New Chemistries for a Growing Demand

Organic electrode-active materials (OAMs) represent an alternative to (transition-) metal-based materials used in conventional battery cells. Reversibly oxidizable p-type OAMs allow realization of full-organic battery cells operating in an anion-rocking-chair mechanism. In the search for p-type materials with a low redox potential, so-called super-electron-donors (SEDs) are a promising class of molecules. Herein, we incorporate a bi(benzimidazole) (BBI)-based SED into three polymers, PBBI, a conjugated homopolymer, PSBBI as a styrene-based side-chain polymer, and X-PSBBI as its cross-linked counterpart. Their properties as potential OAMs in lithium–organic half-cells were investigated, and PBBI was found to be electrochemically inactive. The side-chain polymers showed reversible cycling behavior in binder-free powder electrodes in LiBF$_4$-based electrolytes with a low charge/discharge potential of 2.1 V vs Li$^{+/0}$, even though the accessible capacity quickly faded. As a possible degradation mechanism, we propose decomposition via a dicarbene species as a plausible, reactive key species. This study showcases bi(benzimidazole)s as redox-active groups in OAMs with a low redox potential and provides insight into challenges associated with obtaining reversible cycling behavior in battery electrodes.

Anion-rocking chair batteries, functioning without any metals, are intriguing candidates as alternative, more sustainable energy storage systems. They can be operated by using two types of p-type organic electrode-active materials (OAMs) with low and high redox potentials for the negative and positive electrode, respectively. However, identifying compatible material pairs delivering a potential difference above 1.5 V is challenging. Viologens are promising candidates as low-potential OAMs, but they usually lack stability when cycled over both redox processes. Herein, we report on linear and crosslinked N-aryl viologen polymers with enhanced electrochemical stability over both redox processes in lithium half-cells. We employ these as negative electrodes in anion-rocking chair full-cells with a dimethoxyphenothiazine-polymer-based positive electrode, able to undergo two reversible oxidations. The full-cell, using 2 m LiClO$_4$ in PC as electrolyte, delivered a voltage of ca. 1.8 V and a capacity of up to 78 mAh g$^{−1}$ and could be cycled over 100 cycles with a capacity retention of 71%. We further demonstrate a metal-free all-organic full-cell using nBu$_4$NClO$_4$ as electrolyte salt that delivers an even higher specific discharge capacity of up to 88 mAh g$^{−1}$. This work constitutes a step forward toward anion-rocking chair batteries with attractive cell voltages exceeding 1.5 V.

Redox-active ionic liquids (ILs) represent a promising class of energy carriers due to their intrinsic ionic conductivity, negligible volatility, and electron-transfer capability. However, the design of ILs capable of reversible multielectron storage is still in its infancy. In this work, we report a family of mixed-valence polyoxovanadate-based ionic liquids (POV-ILs) obtained by combining the highly redox-active, mixed-valence cluster ($n$Bu$_4$N)$_4$)$_8$[V$_{14}$O$_{34}$Cl][(MgOH)V$_{13}$O$_{33}$Cl] with a series of bulky quaternary ammonium cations. Cation exchange transforms the solid precursor into liquid-like POV-ILs, dramatically enhancing solubility in organic solvents, such as acetonitrile, THF, and glymes, making them ideal compounds for nonaqueous redox flow batteries (NRFBs). Electrochemical studies demonstrate that these POV-ILs retain the reversible multielectron redox activity of the parent cluster across a wide potential window, enabling their use as symmetric electrolytes in NRFBs. Flow-cell demonstration confirms stable multielectron cycling, with electrolyte remixing mitigating capacity fading. By integrating the redox versatility of POVs with the solubility and processability of ILs, this work establishes a new design strategy for redox-active electrolytes and highlights the promise of POV-ILs for next-generation, high-energy-density NRFBs.

Electrolytes critically influence the electrochemical performance and cycle life of lithium ion batteries (LIBs). This holds especially for organic redox polymer-based batteries, such as those employing poly(3-vinyl-N-methylphenoxazine) (PVMPO), where solubility limits performance in conventional ethylene carbonate (EC)/ dimethyl carbonate (DMC)-based electrolytes. Reducing EC content has shown solubility suppression when using ethyl methyl carbonate (EMC) as a co-solvent, however, capacity fading persists due to PVMPO electrode degradation. To address this degradation, this study explores the use of EC-free electrolytes, with and without fluoroethylene carbonate (FEC). Electrochemical investigations, UltraViolet/Visible (UV/Vis) spectroscopy, post-cycling Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) mapping, and X-ray Photoelectron Spectroscopy (XPS) analyses are employed to evaluate solubility, interfacial properties, and electrode integrity. The EC-free electrolyte system with FEC retains 95 mAh g$^{‒1}$, while that without FEC retains 86 mAh g$^{‒1}$, outperforming the 76 mAh g$^{‒1}$ observed in EC-based systems after 500 cycles at 1C. FEC containing electrolyte systems display reduced interfacial resistance, fewer surface cracks, and minimal electrode degradation. These findings demonstrate that EC-free electrolytes, particularly with FEC, effectively suppress electrode degradation and enhance the cycle life of organic LIBs.

Solid-state batteries (SSBs) are seen as a promising advancement of conventional lithium-ion batteries that use liquid electrolytes. Yet, their current reliance on operation under high stack pressures is a key challenge for wide-scale application. In this context, the composite cathode microstructure is of crucial importance as interface contact between the active material and solid electrolyte as well as charge transport pathways must remain intact under low-pressure operation. In this work, we evaluate the electrochemical charge transport properties of composite cathodes consisting of LiNi$_{0.82}$Mn$_{0.07}$Co$_{0.11}$O$_2$ and Li$_6$PS$_5$Cl at different stack pressures. By using solid electrolytes with different particle size distributions, we investigate how a change in the composite microstructure affects the pressure dependence of effective electronic and ionic conductivities. The effective electronic conductivity is found to be highly sensitive to pressure. Even though the effective ionic conductivity is less sensitive to pressure, it also diminishes when the stack pressure is decreased and approaches practically relevant values. A reduced solid electrolyte particle size leads to higher effective ionic conductivity, but it has no influence on the pressure dependence as such. This demonstrates the need for solid electrolytes that not only feature an optimized particle size distribution but also tailored mechanical properties. Considering the strong pressure dependence of electronic charge transport, SSB cells with and without conductive carbon were tested at different stack pressures. The results highlight the benefits of an electronically conductive additive during low stack pressure operation.

Organic redox-active electrode materials are gaining increasing attention due to their eco-friendliness, abundance, and structural versatility. However, their processing typically depends on poly(vinylidene difluoride) (PVdF) as binder and N-methyl-2-pyrrolidone (NMP) as solvent, both are expensive and hazardous. While aqueous processing methods are well established for inorganic electrodes, their application to organic materials remains largely unexplored. This study investigates the use of water-processable binders, specifically sodium carboxymethyl cellulose (Na-CMC) and styrene-butadiene rubber (SBR) for fabricating poly(3-vinyl-N-methylphenothiazine) electrodes. Key factors influencing electrode performance and microstructure were systematically studied, including the choice of conductive additive, mixing procedures, hot-pressing, and densification. Among these, the selection of conductive additive, mixing method, and room temperature densification at different pressure had the most pronounced impact on electrochemical performance. Electrodes using Na-CMC as the primary binder retained ≈90% of their theoretical capacity over 1000 cycles at 1C rate, comparable to PVdF-based electrodes. While increased densification pressure improved electrode uniformity, it had a detrimental effect on electrochemical performance. Introducing SBR as a co-binder at various weight ratios enhanced mechanical integrity and mitigated the negative effects of high densification pressure, ultimately leading to improved electrochemical performance under these applied operation conditions.

The synthesis of mesoporous carbon thin films is proposed on titanium plates with well-ordered 70 nm mesopores via soft templating of resol resins with poly(ethylene oxide)-block-poly(hexyl acrylate) copolymers. Surprisingly, regular carbonization in pure argon suffers from a metal substrate corrosion not yet observed in literature. This corrosion phenomenon is investigated by secondary ion mass spectrometry, electron microscopy, and X-ray diffraction, and it is identified that the introduction of carbon monoxide into the carbonization atmosphere as successful approach to suppress substrate corrosion without changing microstructure, composition, or pore structure of the non-graphitic carbon. The model electrodes, which consist of a 200–300 nm thick mesoporous carbon layer, the titanium substrate, and a 200 nm thick titanium carbide interphase, are tested for their suitability as electrocatalyst support: The electric transport through and along the thin film is investigated by impedance and Hall measurements and contrasted to similarly mesoporous IrO$_2$ thin films. Accessibility of the pore system and electrochemical stability under acidic water-splitting conditions are studied by SIMS and cyclovoltammetry, respectively. The mesoporous carbon thin films reveal a conductivity similar to IrO$_2$, high stability, and (tunable) accessibility, rendering them a promising model system for several applications like electrocatalysis and sodium-ion batteries.

In the quest for sustainable and metal-free energy storage systems, viologen-based materials offer exciting prospects as they are synthetically well accessible and show two reversible electrochemical processes with anion insertion. This study introduces and compares two π-extended viologen–carboxylate materials bearing double zwitterionic backbones as model compounds based on 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium ([bcbp]): the neutral [bcbp] as a double zwitterionic molecule (1) and its corresponding (Li)$_2$[bcbp](ClO$_4$)$_2$ disalt (2). The choice of these two materials for our electrochemical studies is motivated by the literature available on their synthesis routes and solid-state properties. Electrochemical tests in lithium half-cells revealed that compound (1) is initially inactive but gradually converts into the electroactive disalt (2) via spontaneous chemical insertion of LiClO$_4$ from the electrolyte. Compound (2) directly displays the expected reversible two-electron p-type mechanism involving perchlorate anion (de)insertion, while lithium ions act as spectator species. The system delivers stable cycling performance and high coulombic efficiency, supporting the interest of viologen-based zwitterionic salts as host material for negative electrode application in anionic rocking-chair organic batteries. The bipyridinium-bis(carboxylate) radical ((Li)[bcbp]• (3)) formed during our synthesis optimizations is likewise electrochemically assessed. This fundamental work highlights the tunability of double zwitterionic viologens as molecular platforms to promote optimized p-type negative electrode materials.

Electrolyte development for potassium-ion batteries (KIBs) pose great challenges due to the high intrinsic reactivity of the K-ion system as well as the desired high-voltage application of KIBs, which often trigger strong decomposition of the electrolyte at the electrode interfaces. A common approach to tailor the electrolyte's properties is the use of cosolvents and additives. While their role in lithium- and sodium-based systems is progressively elucidated and even become established as standard cell components, the impact in KIBs still demands for a fundamental investigation. In this study, a comparative analysis of K-ion full cells based on a potassium vanadium phosphate cathode (KVP/C) and a graphite anode employing several electrolyte formulations was carried out to shed light on the complex interrelations of cyclability and the use of prevalent electrolyte additives. Thereby, vinylene carbonate (VC) was determined as most promising additive for next-generation high-voltage KIBs.

We report a compact benchtop solid-state NMR platform that achieves 50 kHz magic-angle
spinning (MAS) in a 1.4 T permanent magnet with an 18 mm bore, enabling high-speed MAS
under extremely space-constrained conditions. The probe architecture leverages field–bore
orthogonality for convenient magic-angle alignment and is demonstrated with miniaturized
1.8 mm rotors (≈5 mm length) at stable high-speed operation. As a demanding test case,
we measure 7Li MAS NMR of the paramagnetic layered cathode oxide LiNi0.5Mn0.5O2,
where hyperfine interactions produce very large paramagnetic shifts spanning the several-
thousand-ppm regime. Overall, the results establish a path toward portable, cost-effective
high-MAS NMR in compact permanent-magnet geometries.

The science and technology behind end-of-life lithium-ion batteries (EoL-LIBs) is a fast-evolving field. Among various solutions proposed to recycle cathode active materials, the solvometallurgy exploiting deep eutectic solvents (DESs) for the leaching of cathode materials is one of the leading research technology due to high efficiencies, low costs of reagents, and absence of wastewater production. In literature, up to now, this method has been exploited to dissolve selected cathode materials and subsequently recover the critical raw materials in the form of salts to be reused for the synthesis of new cathodes. With this work, we propose and demonstrate the feasibility of an innovative and alternative solvometallurgical process, based on the design of a conceptually new DES formulation based on the presence of choline citrate substituting the always-exploited choline chloride, combined with ethylene glycol. This new method enables the leaching of the most relevant and common cathode materials - LiCoO$_2$ (LCO), Li(Ni/Mn/Co)O$_2$ (NMC), LiMn$_2$O$_4$ (LMO), LiFePO$_4$ (LFP), thus providing high flexibility combined with high efficiency. The leap forward and innovation is the new possibility of the direct resynthesis of cathodes, avoiding the step of metals separation; this is intrinsically linked to the new formulation of the DES, avioiding the presence of chlorine. This new strategy can open new ways for the further development of solvometallurgy and efficient recycling of EoL-LIBs.

Rechargeable aluminum batteries (RABs) are promising post-lithium energy storage systems due to the high abundance and volumetric capacity of aluminum, yet stable positive electrodes development remains a bottleneck. Cross-linked poly(3-vinyl-N-methylphenothiazine) (X-PVMPT) as a p-type redox polymer shows reversible two-electron redox chemistry at relatively high potentials and excellent cycling stability in RABs when paired with chloroaluminate-based ionic liquid electrolytes. Here, we present the investigation of volume expansion and morphological evolution of X-PVMPT composite electrodes during cycling using electrochemical (ec-) atomic force microscopy (AFM) and cyclic voltammetry. ec-AFM data reveals the dynamics of reversible expansion during anion insertion and (ir)reversible changes associated with prolonged cycling. In situ linescan profiling and 2D nanomechanical imaging allows visualization of pronounced and reversible volume change during cycling, associated with the insertion of AlCl$_4$$^−$ / Al$_2$Cl$_7$$^−$ anions. Complementary electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) measurements validate these observations at the macroscopic scale, confirming that volume expansion and electrochemical stiffening are homogeneous, bulk phenomena of the X-PVMPT framework. We determined a reversible swelling amplitude of 1.1 ± 0.1 µm during anion insertion for a 9.6 µm thick film, correlated with a 4-fold increase in stiffness. While initial cycles involve large-scale structural changes, the network rapidly reaches a mechanically stabilized state after the initial cycle, where the polymer matrix undergoes irreversible reorganization. After the steady-state phase (from cycle 120 onwards), the swelling amplitude drops by 60-75% to 0.3 – 0.4 µm with sustained faradaic performance, highlighting the ability of the cross-linked matrix to establish ion-conduction pathways during prolonged cycling.

Organic electrode-active materials offer a sustainable pathway toward sodium-based batteries, yet their application is hindered by electrolyte dissolution, limited conductivity, and synthetic challenges. Herein, we present an efficient nickel-free synthesis of poly(pyrene-4,5,9,10-tetraone) (PPTO), a high-capacity organic carbonyl-based polymer, via oxidative Pd-catalyzed homopolymerization of propylene glycol-protected PTO boronic esters. Among different conductive carbon-based electrodes, a PPTO@CNTs@Ketjen Black composite electrode achieves a reversible capacity of 286 mAh g$^{−1}$ at 1 A g$^{−1}$, 72% capacity retention over 500 cycles, and delivers 201 mAh g$^{−1}$ even at 10 A g$^{−1}$. An energy density of 549 Wh kg$^{−1}$ (at low rates) and 346 Wh kg$^{−1}$ (at high rates) is achieved based on active-material mass under half-cell conditions (275 Wh kg$^{−1}$ based on total electrode mass). Ex situ spectroscopy, combined with theoretical calculations, reveals a two-electron redox process of each PTO unit with possible intermolecular interactions stabilizing the reduced state. Kinetic studies demonstrate rapid Na$^+$ transport (D$_{Na}$$^+$ ≈ 10$^{−10}$ cm$^2$ s$^{−1}$) and capacitive-dominated storage. Tomographic 3D image data reconstruction highlights the favorable microstructure of the CNT/Ketjen Black composite in hindering PPTO dissolution. This work provides insights into the interplay between polymer chemistry, electrode architecture, and ion transport, offering design principles for organic electrode materials for sodium-based batteries.

Rechargeable calcium (Ca) metal batteries present an exciting opportunity for electrochemical systems offering high energy density at low costs. Although Ca possesses intrinsic advantages as a metal anode, the feasibility of fabricating thin Ca metal foils for use as practical electrodes remains unexplored. This represents a critical objective for the realization of Ca metal batteries, while it currently limits the research progress in this area. In this study, we introduce a straightforward and effective method for producing Ca foils with a thickness of approximately 100 µm from inexpensive Ca metal chunks. Additionally, we demonstrate that mechanical deformation of Ca can induce alterations in hardness, structural features, and electrochemical properties. The as-prepared Ca foils exhibit enhanced electrochemical performance underscoring that mechanical processing is a key parameter controlling the electrochemical reliability of Ca metal anodes and provides a scalable pathway toward more practical Ca metal battery architectures. This processing method could significantly contribute to the advancement of the research and development of Ca batteries.

Organic electrode materials (OEM)s have emerged as promising candidates for next-generation alkali metal-ion batteries due to their structural tunability, sustainability, and potential for high-rate capabilities. In this work, the role of conductive additives in tuning the electrochemical performance of a typical metal porphyrin-based organic cathode for lithium and sodium-ion batteries was investigated. By varying the type and content of conductive additives including graphene nanoplatelets (GNP), Ketjen black (KB), activated carbon (AC), and Super C (SC), the critical influence of conductive network architecture on capacity, rate capability and cycling stability was identified. Among them, GNP with planar morphology, enables efficient electronic pathways and delivers the highest capacities at low-to-moderate current densities, achieving up to 204 mAh g$^{−1}$ in Li and 229 mAh g$^{−1}$ in Na-ion cells at 100 mA g$^{−1}$. These findings have been elucidated by a combination of theoretical calculations, electrochemical impedance and extended cycling data. It is demonstrated that an optimal balance of conductive additive content and morphology is essential for long-term stability and high-rate performance. This study underscores the role of conductive additive and content in governing the charge transport kinetics of organic electrodes and provides valuable insights for designing high-performance electrode architectures in future sustainable energy storage systems.

Sodium-ion batteries (SIBs) present a promising alternative to conventional lithium-ion batteries (LIBs), offering potential advantages in cost reduction and environmental sustainability. SIBs are in the early stages of development and numerous cathode materials are still being explored. A systematic screening is required to identify the most promising sustainable cathode materials of these early-stage technologies, in line with EU battery regulations and chemical safety strategies. To support such a screening, the evaluation considers major factors such as energy density, cost, greenhouse gas (GHG) emissions, supply risk, and input-related toxicity. As the number of evaluation criteria is high, both the complexity of finding an optimal solution and the impact of linguistic uncertainties in decision-making grow significantly. To address these challenges, a combination of hesitant-intuitionistic fuzzy multi-criteria decision-making (MCDM) is proposed. The hesitant fuzzy linguistic Analytic Hierarchy Process (HFL-AHP) is used to assign weights to the criteria, while the intuitionistic New Easy Approach to Fuzzy-PROMETHEE (NEAT-Fuzzy-PROMETHEE) method is used to rank the alternative materials. Obstacle degree analysis and comprehensive sensitivity assessments are additionally performed to find the field of improvement and ensure robustness with reliability of the results, respectively. The results highlight that the energy density of the cathode material is a critical factor in the screening of optimal solutions. Na$_2$FeSiO$_4$ is the optimal solution when input-related toxicity is not included, while Na$_{0.61}$Fe[Fe(CN)$_6$]$_{0.94}$   becomes a promising option with the inclusion of that factor under given assumptions and limitations of the approach. Furthermore, the analysis shows that energy density, GHG emissions and toxicity affect sustainable decision-making in material screening, indicating critical areas for improvement.

Hard carbon (HC) is currently the predominant anode material for sodium-ion batteries; however, its practical application is still limited by insufficient initial Coulombic efficiency (ICE) and plateau capacity. Meanwhile, conventional HC production relies on energy-intensive carbonization processes with considerable carbon emissions. Here, an induction heating carbonization strategy is developed for extruded biocarbon columns derived from biomass-based biochar and bio-oil, enabling simultaneous enhancement of electrochemical performance and production sustainability. Bio-oil combined with high-pressure extrusion suppresses open pores, whereas induction heating generates localized eddy currents and concentrated Joule heating that accelerate carbon rearrangement and promote closed pore formation. As a result, the closed-to-open pore volume ratio increases from 0.32 to 85.18, leading to improved ICE (95.0% vs. 84.4%) and plateau capacity ratio (77.6% vs. 64.7%) relative to conventional carbonized HC. Life-cycle assessment further indicates an approximately 35% reduction in global warming potential. Overall, this work presents an energy-efficient, low-emission route for producing high-performance HC anodes.

Cobalt selenide (CoSe) has been explored as a cathode material for rechargeable aluminum batteries, particularly under high current densities (1 A g$^{−1}$) with a reported capacity of near 250 mAh g$^{−1}$ at 5 A g$^{−1}$. However, its rapid capacity fading has hindered practical applications, and the underlying mechanisms proposed to be attributed to the intercalation of Al$^{3+}$ remain unclear. In this study, CoSe was synthesized via high-temperature selenization of a ZIF-67 MOF template, and its electrochemical behavior was investigated using operando, in situ and ex situ characterization techniques. Contrary to the previously accepted Al$^{3+}$ intercalation mechanism, we reveal a complex, partially reversible conversion mechanism driven by selenium redox activity. Operando synchrotron diffraction and X-ray absorption spectroscopy show a phase transition from hexagonal CoSe to cubic CoSe$_2$, alongside selenium oxidation from Se$^{2−}$ to (Se$_2$)$^{2-}$. Cobalt remains electrochemically inactive but undergoes structural reorganization and dissolution, forming soluble chloroaluminate complexes that migrate to the Al anode. This process contributes to capacity fade and anode contamination, as confirmed by ex situ SEM-EDX and ICP-OES. At high current densities, the desired electrochemical reactions outpace parasitic side reactions, preserving activity. These findings redefine the charge storage mechanism in CoSe and provide a framework for designing more stable cathodes for long-term RAB performance.

Room-temperature sodium–sulfur (RT Na–S) batteries are emerging as promising next-generation energy storage systems owing to their high theoretical capacity and environmental friendliness. Nevertheless, the intrinsic insulating nature of elemental sulfur and the polysulfide shuttle effect significantly limit the widespread practical and large-scale applications of RT Na–S batteries. Sulfurized polyacrylonitrile (SPAN) is a potential cathode candidate for Na–S batteries, which provides efficient charge transfer due to the conjugated structure of SPAN and avoids the formation of long-chain polysulfide by its structure that only has a short sulfur–sulfur chain. However, the decay mechanism of the SPAN positive electrode in ether-based electrolyte RT Na–S batteries remains poorly understood. In this study, SPAN was studied as a cathode material in ether-based RT Na–S cells. The focus was on the structural evolution of the material during the first few cycles and on variations at different depths of discharge (DOD). This work reveals that deep discharge below 1.0 V affects the structure of SPAN, the equilibrium of polysulfides in the electrolyte, and the growth of sodium dendrites at the negative electrode. On this basis, to enhance the cycling stability and rate performance, carbon-coated functionalized separators are incorporated in the cell.

Sodium-ion batteries (SIBs) are attractive alternatives to lithium-ion batteries owing to their comparable performance, improved safety, and reduced reliance on critical raw materials. Hard carbon (HC) is widely regarded as the most practical anode for SIBs; however, conventional HCs still suffer from limited reversible capacity, poor rate capability, and an incompletely understood Na+ storage mechanism. Here, we investigate hazelnut shell–derived HC synthesized via a sustainable water-washing route, with a particular focus on the effects of particle size and pyrolysis temperature on electrochemical behavior. We demonstrate that smaller particle sizes improve reversible capacity and cycling stability, while uniformly distributed nanoscale inorganic impurities regulate the evolution of pore structure in HC, thereby enhancing Na⁺ storage. A clear thermodynamic relationship between the sloping and plateau capacities is identified. Operando X-ray diffraction and ex-situ Raman spectroscopy reveal that Na$^+$ storage proceeds through chemisorption in the sloping region and diffusioncontrolled Na clustering within pseudographitic domains in the low-voltage plateau, accompanied by reversible structural disordering. Density functional theory and molecular dynamics simulations further confirm that Na$^+$ preferentially chemisorbs at disordered carbon layers at higher potentials and subsequently forms semimetallic Na clusters within nanopores adjacent to pseudographitic layers at lower potentials, closely linked to the pre-adsorbed Na$^+$ species. These findings provide fundamental mechanistic insight into Na$^+$ storage in biomass-derived HC and offer clear guidelines for optimizing HC anodes toward high-performance SIBs.

The transition toward a decarbonized energy system requires long-term energy storage (LTES) solutions capable of complementing hydrogen-based technologies. This study presents an exploratory life cycle assessment (LCA) of a primary aluminum–air battery (AAB) system as a prospective solid-state LTES option, benchmarked against gaseous hydrogen (GH2) with underground storage and liquid hydrogen (LH$_2$) with cryogenic tank. The AAB is evaluated under current and prospective aluminum production scenarios across different geographic contexts, and is benchmarked against alternatives using identical supply chain and use-phase assumptions. AAB system achieves round-trip efficiencies of 29–35%, exceeding GH$_2$ and LH$_2$ by at least 2% and 10%, respectively. Consequently, GH$_2$ outperforms AAB across all categories on a cradle-to-use basis only thanks to underground storage, while AAB showing competitive performance it performs better than LH$_2$ in global warming potential (GWP$_{100}$) impact category. The conducted uncertainty analysis reveals that AAB might outperform H$_2$ in GWP and eutrophication potential (freshwater) under favorable conditions. Overall, the findings highlight trade-offs realizing climate benefits while mitigating resource and ecosystem impacts. Advancing low-carbon smelting, material circularity, optimized logistics, and durable low-impact components will be essential for enabling AAB to serve as a sustainable complement or partial substitute for hydrogen-based LTES in future low-carbon energy systems.

Sodium-ion batteries are treated as a drop-in technology to complement lithium-ion batteries in applications such as entry-level cars and stationary storage. This study compares water-based processing of the sodium-ion battery active material sodium vanadium phosphate (NVP/C) with processing using slurries based on the organic solvent NMP. By utilizing CMC/SBR as a binder, the adhesion strength, flexibility, electrical resistance, and rate capability were improved. These superior properties could be maintained at increasing the drying rate by a factor of 8. However, electrodes processed with the water-based binder system also suffered from binder migration at higher drying rates. To enable high-throughput processing, a strategy involving simultaneous multilayer coating of a primer and electrode slurry was explored. This approach helped mitigate the negative effects of binder migration.

The central focus of existing life cycle assessment (LCA) studies on lithium-ion battery (LIB) cell production has been around cell manufacturing energy, different cathode chemistries, and the supply chain of cathode active materials. In contrast, the crucial role of graphite as the anode active material on the carbon footprint (CF) of LIB cell production has remained largely underexplored. Particularly the differences between synthetic and natural graphite, and their varying compositions in LIB anodes and sourcing are not considered. This work addresses this gap by conducting an LCA on LIB cell production using latest industrial primary LCA data for both graphite types. The results highlight that the CF of LIB cell production is substantially higher (93 kg CO2eq. kWh$^{-1}$) than LIB cell with older graphite datasets (58 kg CO$_2$eq. kWh$^{-1}$), with graphite emerging as a key hotspot (37 kg CO$_2$eq. kWh$^{-1}$, 26.85 kWh kWh$^{-1}$). Results show that the choice and proportion of the graphite types in the anode strongly influence the CF of LIB cell production. Furthermore, the findings reveal the importance of relative
proportions of the two graphite types in benchmarking where different ratios of graphite types may lead to different benchmarking results. Moreover, the origin of the graphite substantially influences the overall CF of LIB cell production. Utilizing graphite sourced from regions with a higher proportion of renewable energy in their electricity mix significantly reduces the CF of cell production compared to graphite sourced from regions with a lower share of renewables. Nevertheless, the study underscores the importance of including the full life cycle data (use-phase and end-of-life) into future assessments to fully capture the effects of different proportions of the two different graphite types on performance and cycle life for a robust decision making on the optimal ratio of graphite in LIB cell design from an environmental perspective. Overall, the study provides important insights for multiple stakeholders by highlighting the pivotal role of graphite, its types, and sourcing in determining the environmental performance of LIB cell.

Sodium-ion batteries (SIBs) are progressively recognized as a viable alternative to lithium-ion batteries due to their operational and economic viability. However, their practical application is limited by lower energy density and intermediate cycling performance, predominantly limited by the cathodes. The exploration of anionic redox in layered oxides has introduced a new approach to enhance the energy density of rechargeable Na-ion batteries. By exploiting anionic redox activity, various positive electrodes are capable of providing additional capacity beyond their theoretical capacity. This additional capacity emerges from the combined contributions of anionic and cationic redox processes. However, the anionic capacity achieved during charge is often only partially reversible upon discharge, posing a significant challenge for practical use. This review offers a comprehensive analysis of anionic redox phenomena in sodium-based layered oxides, summarizing recent research strategies aimed at improving the anionic and cationic redox performance of these cathode insertion materials. It also elucidates the relationship between structure, function, and electrochemical performance. Eventually, it provides insights into the future research directions for Na-based layered oxide cathodes for energy storage applications.

Probing the solid/liquid interface of batteries operando/in situ with ambient pressure X-ray photoelectron spectroscopy (APXPS) using the dip-and-pull method remains a challenging endeavor due to spatial and temporal variations in liquid layer shape, thickness, and composition. Monitoring the electrochemical and topographical nature of the liquid edge where the interface is accessed is essential to correctly interpret interfacial spectra. In this work, a methodology combining experimental design and software-based data processing for interface probing is reported. This experimental methodology utilizes continuous motion during fixed-mode APXPS measurements by periodically scanning across the dry electrode and thick electrolyte regions to capture the transitional interface. Two software-based approaches for retrieving the interface spectra are evaluated. In an analysis of the intensity attenuation pattern of a unique electrode signal, interface spectra are recognized at the edge of the intensity transition from electrode to electrolyte. The second method utilizes peak positions for interface identification. Selected spectra with the same peak energies also exhibit the same chemical features, indicating the close correlations between the interface energetics and local chemical compositions. Further, topographical information can be extracted using scanning APXPS by translating spectral intensities into liquid thickness, creating a spectro-microscopic 3D image of the liquid edge region. In the examined systems, the thickness of a propylene carbonate electrolyte edge on both lithium cobalt oxide and gold WE surfaces exhibits a step-jump transition from the thin to thick liquid region. The liquid distribution is also shown to depend on the morphological and chemical nature of the electrode. The imaging provides a better understanding of the relationship between liquid distribution and probed interface features while validating the functionality of the setup.

Lithium-ion batteries (LIBs) are considered a key technology for the energy and mobility transition. But the high demand for LIBs causes an increasing demand for critical raw materials (CRMs), like lithium, cobalt, graphite and nickel. Furthermore, there are concerns that the well-established LIB technology is falling short on environmental and social expectations, pointing out issues of human exploitation, including forced- and child labour. Currently, sodium-ion battery (SIB) technology is promoted as complementary to LIBs, but based on abundant resources. While SIBs are considered a promising alternative in some applications, with potential environmental advantages in the future, little is known regarding their potential social risks and impacts. This study uses Social Life Cycle Assessment (S-LCA) methodology to explore the potential social impacts of a representative emerging SIB in comparison to LIB. The focus is on the raw material extraction phase, and the investigated impact categories include child labour, trafficking in persons, fair salary, trade union density, disability-adjusted life years (DALY) due to indoor and outdoor air and water pollution, and the contribution of the sector to economic development. Except for the DALY, SIBs portrayed a better potential social performance, mainly due to the absence of CRMs such as cobalt and lithium.

The large-scale deployment of stationary battery storage is critical for enabling renewable energy integration, yet life cycle assessments (LCAs) of these systems often overlook the contributions of balance-of-system (BOS) components. This study establishes a life cycle inventory (LCI) model for two container storage systems (CSSs), a liquid-cooled and an air-cooled system. Consequently, a full LCA is carried out with four different cell types, focusing on sodium-ion batteries (SIBs). The resource and environmental impacts of all BOS subsystems, including containers, thermal management systems (TMSs), power converters, control systems and auxiliary components, are investigated in detail. The results show that BOS components contribute between 32 and 58% of impacts in global warming potential (GWP) and 63–88% in resource use, minerals and metals, emphasizing their significant role in the sustainability of grid-scale storage. Due to its high demand for copper and steel, a transformer is particularly important in this regard. However, the environmental impact attributable to its production can be reduced through correct dimensioning and adequate recycling. It is further shown that SIBs are competitive with lithium-ion batteries in CSSs with regard to environmental impacts, despite their lower energy densities. By shedding light on previously underexplored system elements, this work provides a robust foundation for more comprehensive LCAs of containerized battery storage solutions and enables more informed design, scaling, and policy decisions for future energy systems.

Hard carbon (HC) is commonly used as negative electrode material in sodium-ion batteries. Despite its extensive use, there is still a lack of comprehensive understanding of the sodiation mechanism. To obtain thermodynamic information on the storage processes, the reaction entropy of HC/Na metal cells in NaPF6/diglyme electrolyte solution is determined by measuring the temperature dependence of the equilibrium cell voltage at different states of charge (SoCs), commonly known as entropy profiling. In contrast to former studies, we changed the temperature of the cell stepwise within less than 1 min, which reduces the influence of baseline drift of the cell voltage. The cell reaction entropy varied between −10 and 6 J mol−1K−1 for all SoCs, which indicates complete solvation/desolvation of the Na+ ions at the HC composite electrode. In addition, the fast temperature change led to characteristic features of the cell voltage response. These features were explained with a simple model including temperature gradients across the cell and different kinetics of the reactions at the HC and the Na metal electrode. From the cell voltage response, we inferred that the sodiation of HC is significantly slowed down with decreasing SoC.

Solid-state dewetting is the process by which thin solid films break up and retract on a substrate, forming nanostructures. While dewetting of single-crystalline films is understood as a surface-energy-driven process mediated by surface diffusion, polycrystalline films exhibit additional complexity due to the presence of grain boundaries. Most theoretical and computational studies have focused on single-crystalline dewetting. Here, we present the application of the grand-potential multi-phase-field model to the dewetting of thin polycrystalline films in three dimensions, reproducing the key phenomenology of this process. By considering isotropic interface/surface energy, we illustrate its consistency with predictions based on energetic arguments and the morphological evolution towards equilibrium. We also provide novel analytical criteria for the onset of three-dimensional dewetting, serving as fundamental theoretical benchmarks, and highlight the critical role of triple junctions. Moreover, we unveil the dewetting behavior of polycrystalline patches, extending the scenarios of their single-crystalline counterparts.

The characteristics of the gas itself, such as its volatility, compressibility, or weight, often complicate the process of feeding gas into a measuring system, such as a gas chromatograph. This is particularly relevant when quantifying individual gas components. While it is possible to inject gas with syringes, this method has several disadvantages, such as gas tightness and syringe and gas volume, especially for small gas quantities. Therefore, there is an urgent need for a simple, reliable, and improved method of gas injection into a measuring device. This study describes the development of a novel gas injection system that reliably and contaminant-free injects gas into gas chromatography (GC) instruments and other gas-related devices. The system consists of an injection unit, a vacuum system, and a loop assembly, and it connects directly to the corresponding device. Sample gas can then be introduced directly into the evacuated injection system and delivered to the measuring device. The system has been validated using a range of configurations and has undergone extensive testing. Additionally, two applications are presented to demonstrate the system's wide range of potential uses. Notably, the setup enables a contamination-free gas supply from battery pouch-bag cells. For this configuration, an adapter assembly was required for the pouch-bag cell and was integrated into the battery cell. Additionally, it is demonstrated how the setup can be used to determine the gas composition of a thermal decomposition reaction. This setup is a new, platform-independent option for introducing gas into a low-pressure environment and connecting it to devices without causing contamination. Reduced pressure enables multi-point calibration with a single reference or calibration gas mixture, which is pressure-dependent. Additionally, the integrated loop technology allows for the quantitative calculation of gas concentrations. Errors in calculating the amount of substance are less than 10–20%, even with flexible pouch cells.

Spray-dried battery active materials exhibit high specific surface area and tap density, enhancing battery performance with superior rate capability and initial capacity. However, this morphological optimization induces severe interfacial side reactions, causing rapid capacity fading. Herein, this study reports a novel wet chemistry coating method using hydrogen peroxide as an activation agent. Inspired by niobium-based oxide coatings for lithium-ion battery materials, this method is adapted for the sodium system with P2-type Na$_{7/9}$Mn$_{6/9}$Cu$_{2/9}$Fe$_{1/9}$O$_2$ layered sodium oxides. Despite the adverse effect of hydrogen peroxide on active material performance, this coating method retains significant advantages in time efficiency and scalability with uniform coating on the active material surface. Consequently, the surface modified material achieves remarkable capacity retention of 97% after 200 cycles at a current rate of 120 mA g$^{−1}$ within a voltage window of 1.5–4.2 V with presodiated hard carbon electrode, much higher than that of pristine material (54%). Postmortem analysis of cycled electrodes and electrochemical impedance spectroscopy results confirm the well-covered material surface with suppressed side reactions, extending the battery cycling life. Additionally, powder X-ray diffraction and X-ray photoelectron spectroscopy analyses validate the temperature-dependent coating and substitution behaviors of the coating material.

The growing demand for efficient energy storage systems directs substantial research attention toward aluminum–air batteries, primarily due to their low cost and the abundant availability of aluminum. Among the various strategies aimed at enhancing their performance, the incorporation of electrolyte additives emerges as one of the most cost-effective and efficient approaches. Elec-
trolyte additives, usually constituting approximately 1% of the total electrolyte composition, actively influence the physicochemical characteristics of both the electrolyte and the electrode–electrolyte interface, thereby contributing to marked enhancements in the overall performance of aluminum–air batteries. Despite their low concentrations, additives play a fundamental role in enhancing the efficiency and extending the service life of aluminum–air batteries by stabilizing the electrode–electrolyte interface and promoting favorable electrochemical performance. This review investigates the primary factors propelling the advancement of aluminum–air batteries by considering the diverse functions of electrolyte additives. The additives are classified into three categories: organic, inorganic, and hybrid. This comprehensive analysis aims to serve as a key resource for the informed selection and development of electrolyte additives, thereby fostering continued innovation in aluminum–air battery technologies.

Models based on the coupling of phase-field methods with fluid dynamics are commonly used to simulate flow in complex geometries or in conjunction with phase transformation. Thereby, diffuse interfaces between fluid and solid are used, which requires the corresponding diffusive application of the boundary conditions with regard to the flow. While different approaches to achieving this are found in literature, a quantitative comparison of these methods is still missing. The present work aims to establish benchmarks addressing the diffuse fluid–solid transition for interfaces with and without wall velocity. Furthermore, different models from literature are revisited and comparatively discussed in detail. Using the defined benchmark cases, a quantitative assessment of these models is performed to investigate their accuracy for varying interface widths and different phase-field profiles. The results show that the best choice of the diffuse model is problem-dependent.

Predicting the macroscopic properties of thin fiber-based porous materials from their microscopic morphology remains challenging because of the structural heterogeneity of these materials. In this study, computational fluid dynamics simulations were performed to compute volume air flow based on tomographic image data of uncompressed and compressed paper sheets. To reduce computational demands, a pore network model was employed, allowing volume air flow to be approximated with less computational effort.
To improve prediction accuracy, geometric descriptors of the pore space, such as porosity, surface area, median pore radius, and geodesic tortuosity, were combined with predictions of the pore network model. This integrated approach significantly improves the predictive power of the pore network model and indicates which aspects of the pore space morphology are not accurately represented within the pore network model. In particular, we illustrate that a high correlation among descriptors does not necessarily imply redundancy in a combined prediction.

Recently, research developments on layered-spinel composite cathodes have surfaced as a promising approach to improving the electrochemical performance of cathode materials for sodium-ion batteries (SIBs). Here, a P2/P3 layered-spinel composite, (P2/P3-LS-Na1/2Mn2/3Ni1/6Co1/6O2 (LS-NMNC)), has been synthesized and evaluated as a promising cathode material for SIBs. The material exhibited distinct electrochemical characteristics across different voltage ranges of 1.50–4.00 V and 1.50–4.50 V. In operando X-ray diffraction and X-ray absorption spectroscopy were employed to investigate the remarkable charge capacity and rapid capacity degradation observed in broader voltage range. It was determined that material undergoes various electrochemical mechanisms when adjusting the upper cut-off voltage. A unique Co3+/Co2+ redox process was activated during the intercalation of sodium ions at a potential of 1.94 V within 1.50–4.00 V range, accompanied by a phase transition from P2/P3 to P′2/O′3. This phase transition, in conjunction with the Co3+/Co2+ redox process, is likely responsible for the enhanced structural stability and capacity exhibited by the material when upper cut-off voltage is restricted. Additionally, presence of an anionic redox couple and strain in the structure was noted with the increase in the upper cut-off to 4.50 V, which leads to instability and diminished electrochemical performance.

Aqueous Mg-ion batteries (AMIBs) have emerged as promising candidates for grid-level energy storage systems, thanks to their exceptional safety characteristics, cost-effectiveness, and abundant Mg resources. However, AMIBs confront great challenges, such as the shortage of high-performance electrodes and the sluggish Mg2+ diffusion in the electrodes. In this work, a Mg2+-regulated bilayered vanadium oxide (MgVOnH) positive electrode, holding a large interplanar spacing of ∼13.4 Å, was investigated in 0.8 m Mg(TFSI)2–85% poly(ethylene glycol) (PEG)–15% H2O and 0.8 m Mg(TFSI)2–65% PEG–20% dimethyl sulfoxide (DMSO)–15% H2O (20% DMSO-containing) electrolytes. MgVOnH delivers a first discharge capacity of 268 mAh g–1 at 50 mA g–1, obtaining 81% capacity retention after 100 cycles (against a second discharge capacity of 249 mAh g–1) in a DMSO-free electrolyte, whereas MgVOnH exhibits much better rate capability and high capacity at 500 and 1000 mA g–1 in the DMSO-containing electrolyte, respectively. Particularly, MgVOnH shows a first discharge capacity of 106 mAh g–1 at 1000 mA g–1, maintaining 80/65% of its capacity after 920/2000 cycles. Furthermore, the electrochemical reaction mechanism and reversibility of MgVOnH during Mg2+ (de)intercalation are systematically explored through ex situ techniques. This work helps us to understand the mechanisms, and this can guide us in achieving a better design for high-performance positive electrodes for AMIBs.

Sodium-ion batteries (SIB) have recently emerged as an alternative to current lithium-ion batteries (LIB), using low-cost and abundant raw materials. However, previous assessments have come to controversial results regarding their economic competitiveness, and the potential impacts of SIB on the wider energy system are still unexplored. This study combines a bottom-up cost modelling including future performance developments on material level for SIB with a global energy system model to obtain a comprehensive assessment of the potential impact of SIB on the global energy-industry transition until 2050. The results show that with recent cost developments and learning curves, batteries are no longer a cost-critical component in the energy system with projected utility-scale battery system capex of 28.5–51.9 €/kWh$_{cap}$ by 2050. SIB potentially outperform LIB on the medium term and are less prone to price spikes and supply shortages. Being a so-called drop-in technology, they could be produced on existing LIB production lines with only minor modifications. Therefore, concerns about supply shortages or price increases can be seen as resolved, since any disturbance in LIB supply would simply trigger a shift to SIB. The overall energy system structure remains virtually unaffected, with similar solar photovoltaic shares, but a shift in power-to-X processes operation. In this sense, electrochemical energy storage is not found to be a limiting factor for the global energy transition. Correspondingly, this work projects the possibly highest stationary battery demand published with a range of 67.9–106.5 TWh$_{cap}$ by 2050, above those in existing cost-optimised energy-industry system analyses.

Aqueous zinc-ion batteries are emerging as potential candidates to cater low-cost stationary energy storage due to the abundance, economic and ecological benignity of zinc. Among the various cathode materials, vanadium-based compounds have garnered significant attention owing to their structural diversity, Zn$^{2+}$ storage capability, and high theoretical capacity. The electrochemical activities in these cathodes can be tuned by modulating their structure, particle morphology, surface coatings and local structural (dis)ordering. This study probes the role of disorder on the electrochemical performance of ZnV$_2$O$_4$ spinel cathodes. Without any surface or structural optimization, ZnV$_2$O$_4$ delivers a specific capacity of 150 mAh g$^{−1}$ with stability over ≈1000 cycles at a current density of 1 A g$^{−1}$. Using operando and ex situ techniques – including electron microscopy, X-ray diffraction, X-ray absorption, and Raman spectroscopy – it is revealed that initial cycling induces a conversion reaction, forming a disordered Zn-deficient vanadium oxide phase. This phase enables reversible Zn$^{2+}$ (co)insertion, enhancing long-term performance. This findings highlight the critical role of disorder dynamics in tuning the electrochemical behavior of spinel ZnV$_2$O$_4$, offering valuable insights for designing advanced spinel cathodes for secondary zinc-ion batteries.

Magnesium (Mg) is set as a viable alternative battery material to lithium (Li) owing to its cost, natural abundance, and safety. Nevertheless, the formation of dendrites on Mg anodes remains controversial. While some studies refute their existence, others report contradictory findings influenced by current density and the insufficiently understood roles of electrolyte formulation, additives, and temperature. In this work, these parameters are systematically investigated using symmetric Mg|Mg and asymmetric Mg|TiS$_2$ cells with tailored ionic-liquid-based electrolytes. Furthermore, operando optical microscopy is employed to visualize nucleation and dendritic growth at different current densities. At low current densities (0.1–0.5 mA cm$^{−2}$), non-uniform island-like Mg deposits evolved into soft dendrites, finally leading to short-circuiting. Contrary, higher current densities (1–5 mA cm$^{−2}$) promote uniform, spherical deposits and facilitate stable cycling over 700 cycles. In Mg|TiS2 asymmetric cells, enhanced cycling stability is observed at 50 mA g$^{−1}$, whereas soft dendrite formation at 10 mA g$^{−1}$ leads to cell failure within 30 cycles. Taking advantage of Mg's safety, cycling of symmetric cells are continued even beyond dendrite-forming to study morphological and mechanical recovery. Notably, our analysis reveales self-healing due to dendrite fusion in previously short-circuited cells. These findings reveal conditions affecting Mg dendrite behavior, highlighting the key roles of current density and temperature in developing stable, rechargeable Mg batteries, and reporting self-healing in Mg batteries for the first time.

[5,15-bis(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP) composite cathodes for rechargeable magnesium-ion batteries have been investigated before, after, and during initial cycling (pristine, first charging, and consecutive discharging). The initial self-conditioning is studied by scanning electron microscopy and spectroscopy-based methods (energy-dispersive X-ray spectroscopy, total reflection X-ray fluorescence spectrometry, and Raman spectroscopy) as well as time-of-flight secondary ion mass spectrometry (ToF-SIMS) and orbitrap SIMS (Orbi-SIMS). This study shows that copper is released from the active material into the electrolyte solution during the initial cycling at potentials higher than 3.1 V versus Mg2+/Mg. The results point toward a transmetalation process transforming CuDEPP into [5,15-bis(ethynyl)-10,20-diphenylporphinato]magnesium(II) (MgDEPP). Further, the self-conditioning process via electro-polymerization observed for monovalent ions appears to be absent in the investigated Mg-based system, as the alkynyl group of the CuDEPP seems to remain unaltered during the initial charging and discharging steps. Additionally, cross-sectional and laterally resolved ToF-SIMS image analyses show an accumulation of inorganic fluorine-rich copper and magnesium species at the electrode surface including the active material exposed to the electrolyte after cycling that might be a result of a passivation layer or the formation of a cathodic electrolyte interphase.

The unstable solid-electrolyte interface (SEI) poses a major obstacle to the widespread use of rechargeable magnesium batteries (RMBs) as high-volumetric-capacity next-generation energy storage systems. This issue is effectively mitigated by adding 3 wt.% tris(trimethylsilyl) borate (TMSB, C9H27BO3Si3) to a state-of-the-art Cl-free magnesium tetrakis(hexafluoroisopropyloxy)borate in dimethoxyethane (Mg[B(hfip)(4)](2)/DME) non-aqueous electrolyte. The modified electrolyte enables stable Mg||Mo6S8 (Chevrel phase, CP) full cell operation for up to 1000 cycles at a 1C rate. Tip-enhanced Raman spectroscopy (TERS) reveals that TMSB scavenges degraded electrolyte components and facilitates the formation of a uniform and thin SEI on the magnesium anode. Reflection anisotropy spectroscopy (RAS) further demonstrates that TMSB transforms the interfacial structure, creating a more isotropic and robust SEI during the initial stripping and plating process, thereby extending electrochemical cycling stability. This approach presents a compelling pathway for practical RMB development by stabilizing the SEI and optimizing magnesium electrolyte formulations.

Sodium-ion batteries (SIBs) show promise for the next generation of energy storage technology but face significant challenges in regards to stability due in part to uncontrolled degradation of the solid electrolyte interphase (SEI). Kinetic Monte Carlo (kMC) modeling is uniquely suited to provide molecular-scale insight on the phenomena that influence SEI growth and behavior in SIBs over full charge. In this work, spatially- and time-dependent electrical potential is incorporated into kMC modeling for the first time, which enables the precise study of electrochemical reactivity and SEI growth during charging. A reaction network for a carbonate/NaPF6 electrolyte developed using density functional theory is used to power the kMC simulations. The decomposition of NaPF6 and formation of NaF is unfavorable at standard conditions, suggesting that water or other contaminants are required to facilitate the reaction. The SEI is shown to be primarily made of Na2CO3. SEIs with low electric conductivities exhibit the most ideal behavior and high C-rates generate thinner SEIs with greater fractions of organic species. Dissolution of SEI species is shown to occur rapidly, even during formation. The results of the model correspond well to the SEI behavior known in the literature, and reveal the fundamental mechanisms that influence cell behavior.