Emerging and safer rechargeable battery technologies such as sodium-ion batteries have attracted much attention in recent years due to the low cost and large natural abundance of sodium sources. Non-graphitic hard carbons (HC), formed by randomly orientated and curved graphene sheets with expanded interlayer distance (3.6–4 Å) and with the possibility of being derived from biosources, are promising anode candidates for Na-ion batteries, showing typical reversible capacities of ca. 300 mAh g⁻¹. The reaction mechanisms that drive the sodiation/desodiation properties in hard carbons are complex and relate to (1) Na⁺ ion adsorption at edge sites and defects, (2) Na⁺ intercalation into graphene–graphene interlayer spacing, and (3) Na⁺ ion insertion into nanopores. These storage mechanisms and their subsequent electrochemical response are strictly linked to the characteristic slope and plateau regions observed in the voltage profile of these materials.

In this work we show that electron paramagnetic resonance (EPR) spectroscopy is a powerful and fast diagnostic tool to predict the extent of the charge stored in the slope and plateau regions during galvanostatic tests in pristine hard carbon materials. EPR lineshape simulation and temperature-dependent measurements help to separate the nature of the spins in mechanochemically modified hard carbon materials synthesised at different temperatures. This proves relationships between structure modification and electrochemical signatures in the galvanostatic curves to obtain information on their sodium storage mechanism. Furthermore, we show through the use of ex-situ EPR the evolution of these EPR signals at different states of charge to further elucidate the storage mechanisms in these hard carbons, to answer questions related to the nature of the Na clusters. 

Carbon materials have been widely used as main components or conductive additives in the electrodes of various electrochemical devices, including supercapacitors [1], Li-ion batteries [2], and beyond Li-ion batteries [3, 4]. The stability of carbon materials is an important but often overlooked factor that determines battery safety. Compared with the relatively more stable carbon basal plane, the key structural feature that may be the origin of oxidation reactions in carbon materials is carbon edge sites. To precisely quantify carbon edge sites, we have developed a unique temperature-programmed desorption (TPD) technique with an upper limit temperature of 1800 ^oC [5]. Using advanced TPD, we found a strong correlation between the number of H-terminated and oxygen-functionalized carbon edge sites and carbon electrode corrosion in supercapacitors [6]. In addition, the amount of carbon edge sites also controls the stability of Li-O₂ batteries [7]. By combining differential electrochemical mass spectrometry with isotopic ¹³C labeling techniques, we have investigated the carbon electrode corrosion mechanism in Li-O₂ batteries [8]. In our recent work, we also explored how carbon edge sites affect SEI formation, ion diffusion, and rate performance in Na-ion batteries by using TPD together with other comprehensive characterization techniques. In this talk, I will summarize our recent progress in determining the degradation caused by carbon electrodes in advanced batteries.

The accelerating miniaturization of electronics has created a pressing need for equally small yet powerful energy sources that can sustain autonomous microsystems and robotic devices at sub-millimeter scales. While most battery research has focused on large-scale systems—from consumer electronics to electric vehicles and the grid—the challenge of delivering energy to sub-millimeter devices remains largely unresolved. Zinc-based batteries present a compelling solution: they are stable in air, inherently safe, and seamlessly compatible with microfabrication processes, offering distinct advantages over conventional lithium systems when scaled down.

Despite these advantages, realizing high-energy-density storage below 1 mm² has been limited by both materials constraints and architectural bottlenecks. Our research addresses these barriers by introducing micro-origami fabrication, where thin-film layers are folded into compact Swiss-roll structures. This strategy has enabled zinc batteries that shatter the footprint boundary of 1 mm², achieving capacities above 1 mAh cm^-2 and reaching into the deep-submillimeter regime (< 0.1 mm²). Equally important, advances in photolithographable polymer electrolytes now extend cycling stability, opening a pathway to long-lived energy storage directly integrated on-chip.

Beyond storage, new chemistries—such as cathode-free concepts, halogen cathodes, and decoupled electrolytes—are beginning to expand the functional space of zinc microbatteries. In parallel, coupling these devices with micro-actuators demonstrates how zinc ion dynamics can be harnessed not only for powering but also for driving motion. Together, these developments point toward a new class of functional microsystems where actuation and energy storage are intertwined, providing a blueprint for the next generation of intelligent machines at sub-millimeter scales.

Aqueous zinc metal batteries are attractive for long duration and grid scale energy storage because they are intrinsically safe, sustainable, and based on low cost, abundant materials. However, their broader adoption is still limited by challenges at the zinc metal anode, including dendrite formation and parasitic reactions associated with water reduction. These processes undermine reversibility and make it difficult to achieve long term cycling stability at practical current densities.

Our work introduces an electrolyte design strategy that enables stable zinc plating and stripping without relying on traditional highly concentrated water in salt formulations. We show that the local zinc ion coordination environment can be tuned to resemble water in salt behavior even in moderately dilute electrolytes when using coordinating, non-fluorinated anions such as acetate. This provides the interfacial and solvation benefits typically associated with concentrated systems while preserving the high conductivity, low viscosity, and lower environmental footprint of dilute electrolytes. The results highlight that extreme salt concentrations are not necessary for dendrite suppressed zinc deposition; instead, the coordination strength and identity of the anion emerge as key molecular design parameters.

In parallel, we investigate complex zinc electrolyte systems that contain supporting salts and demonstrate how their composition alters zinc ion solvation, ion transport, and concentration polarization, all of which strongly influence dendrite morphology and high rate performance. Because standard approaches such as the Bruce Vincent method do not accurately quantify cation transference numbers in multicomponent electrolytes, we developed a new measurement framework that resolves the transport contributions of zinc ions and the accompanying ions in solution. This enables a mechanistic link between electrolyte composition, transport behavior, and interfacial stability.

Taken together, these insights establish a path toward environmentally benign, low cost aqueous electrolytes that support stable, high-rate zinc metal cycling. By coupling controlled solvation chemistry with accurate ion transport characterization, our work provides design principles for next generation zinc-based batteries that can meet the needs of grid energy storage systems.

Lithium phosphate NASICON-type electrolytes are promising candidates for enabling high-energy-density and safe batteries. Moreover, their stability in air and moisture, combined with a composition that relies on few critical raw materials, makes them excellent candidates for practical implementation. However, the interfacial instability between the NASICON-type solid electrolytes and the Li metal anode remains a critical bottleneck for the practical deployment of all-solid-state lithium batteries. When put in contact, the highly reductive potential of Li metal reduces the transition metals of the electrolyte. This process leads to the formation of a mixed conducting interphase (MCI), accompanied by amorphization, electrolyte decomposition, and mechanical pulverization, causing rapid capacity fade after only a few cycles. To mitigate this issue, we deposited a 200 nm protective thin film of metallic titanium (Ti) onto the Li1.5Al0.5Ge1.5(PO4)3 (LAGP) surface using magnetron DC sputtering. This interfacial modification promotes the in-situ formation of lithium titanate species (LixTiyOz), which stabilize the interface and extend the operational lifespan of LAGP-based cells. In this presentation, we will highlight the enhanced electrochemical performance of these surface-engineered cells and provide structural characterization by operando Raman and post-mortem analysis to elucidate the mechanisms underlying the observed improvements.

The growing demand for extended-range electric vehicles has renewed interest in replacing conventional metal-ion batteries with higher energy-density metal-anode batteries, such as lithium, sodium, and zinc. However, metal cells often suffer from capacity fading and potential safety issues due to uneven metal electrodeposition. Understanding metal plating mechanisms is crucial for developing the next generation of rechargeable batteries with high energy density, prolonged cycle life, and improved safety.

“Soft shorts” are small, localized electrical connections between electrodes that allow simultaneous electron transfer and interfacial reactions. Although soft shorts were identified as a potential safety concern in lithium-ion batteries as early as the 1990s, their detection and prevention have been relatively understudied. Using coupled electrochemical impedance spectroscopy (EIS) and operando NMR, we demonstrated that transient soft shorts could form under realistic battery cycling conditions.

Interestingly, the typical rectangular-shaped voltage trace, often considered ideal, was shown in our study to result from soft shorts under these conditions. We further demonstrated recoverable soft-shorted cells in symmetric cell polarization experiments, defining a new type of critical current density: the current density at which soft shorts are no longer reversible. Importantly, soft shorts were found to be predictive of subsequent hard shorts, highlighting the potential of EIS as a relatively low-cost, non-destructive method for early detection of catastrophic short circuits and battery failure. [1]

These results underscore that a fundamental understanding of soft short circuits, coupled with reliable detection methods, is critical for realizing safer metal-based batteries, including metal-air, metal-sulphur, and anode-free configurations.

Zinc metal anodes have gained increasing attention due to the sustainability of aqueous electrolytes. However, deeper insights into zinc plating, hydrogen evolution, and corrosion mechanisms are essential. In our SECM studies of zinc plating, we compared the effects of various electrolyte compositions on SEI heterogeneity, zinc morphology, and soft short formation. [2]

One way to improve the safety of lithium-ion batteries is to replace the flammable organic electrolyte with a water-based alternative. However, due to its narrow electrochemical stability window of 1.23 V, water alone is not suitable for Li-ion battery applications. This limitation can be overcome by employing a water-in-salt electrolyte (WISE) since high salt concentration significantly decreases the molecular activity of water, thereby preventing the decomposition of water with the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Therefore, the electrochemical stability window (ESW) of the electrolyte can be widened up to 3 V once high concentration LiTSFI (21 m) is employed.

Unfortunately, experimental evidence shows that HER is still taking place and is reported as the primary source of parasitic reaction responsible for cell failure and poor electrochemical performance. Here, we investigate the ageing mechanism occurring in LiFePO4/TS2 full cell using water-in-salt electrolyte. By using bulk and surface characterisation techniques (XRD, XPS, SEM, HAXPES, XAS, OEMS, etc.), we will shed light on the ageing mechanisms and explain the possible trategies to keep improving water-in-salt system. As an example, we tuned the electrochemical parameters (applied C-rate, cut-off potential, electrolyte concentration) and as can be seen in Figure 1a, the cut-off potential drastically influences the electrochemical curves since more reversibility are obtained from the electrode cycled with a lower cut-off. Additionally, we employed X-ray Absorption Spectroscopy (XAS) at Fe K-edge (Figure 1b) to probe LiFePO4 electrode after a full delithiation in WISE electrolyte. Despite likely HER reaction occurring during the first delithiation, LiFePO4 electrode is properly delithiated but not following a complete linearity imposed by its biphasic nature. Indeed, there is almost no difference between the pristine LiFePO4 and the one cycled at 25%SOC, indicating that the first delithiation process might be linked to parasitic reaction (SEI, or others). Additional surface sensitive techniques such as X-ray Photoelectron Spectroscopy (XPS) and Hard X-ray Photoelectron Spectroscopy (HAXPES) will be used to complete the picture of ageing mechanisms occurring in water-in-salt electrolyte.

Greener emerging technologies are arising to substitute dominant Li-ion batteries due to their high costs and safety issues. The development of energy storage systems based on zinc technologies, such as Zn-ion hybrid supercapacitors (ZHSCs)^1-2 is one these emerging technologies, due to its simplicity, its compatibility with water and stability. ZHSCs uses Zn as anode and capacitive carbon electrodes as cathode, with offers the possibility to hybridize them by incorporating redox-active nanomaterials to obtain higher energy density and longer cyclability^3-4. Prussian Blue (PB, nanocubes made from Fe, N, and C) and its analogues (Co, Cu, Ni) have emerged as interesting faradaic nanomaterials for Zn-ion technologies due to their ability to intercalate cations (Na⁺ and Zn⁺²) inside their crystalline structure.⁵ However, PB often suffers from crystalline defects problems that reduce their potential performance, together with low kinetics due to large sizes of the particles.³ In this sense, the development of novel synthetic approaches to control their nanostructure and size become an important factor in order to obtain high diffusion PB.^6-7 In addition, for a real development of more efficient devices, focusing only on electrode materials is not enough. Innovation towards more respectful and eco-friendlier electrode fabrication, together with a tailored electrode engineering is mandatory. In this sense, this work combines the development of novel nanoconfined synthetic approaches for obtaining good ion diffusion Prussian Blue nanomaterials with the fundamental study of their incorporation the microstructure of a hybrid free-standing electrode for dual zinc-ion supercapacitors.

Advancing energy materials is crucial to meeting the increasing demand for efficient and sustainable energy storage systems. Among these, polycrystalline layered LiNi_0.8Mn_0.1Co_0.1O₂ (PC NMC811) cathode materials are widely used in state-of-the-art electric vehicles due to their high storage capacity. However, capacity degradation, partly triggered by cathode cracking, remains a significant bottleneck. Our previous research [1] has shown that the mechanical strength of PC NMC811 reduces during delithiation, underscoring the need to investigate its chemical composition in this state. Conventional materials characterisation techniques face limitations, such as air exposure, beam damage, and difficulties in detecting light elements such as Li.

To address these challenges, we employ a fully cryogenic materials characterisation workflow, where the material is frozen in liquid nitrogen in a partially delithiated state and transported between the microscopes using a vacuum transfer suitcase. Using a plasma Focused Ion Beam (pFIB) microscope, we lift out a sample containing the PC NMC811 and electrolyte interface and subsequently fabricate a thin needle for Atom Probe Tomography. This setup is unique in the world, and experiments involving delithiated NMC811 are extremely challenging owing to the mechanical instability of the material. Obtaining this data represents a significant achievement, highlighting the importance and complexity of the experimental methods employed.

Here, we report nanoscale chemical composition variations in delithiated PC NMC811 using Atom Probe Tomography. By comparing these results to lithiated NMC811 nanoscale composition, we can make predictions on local chemistry evolution as a function of state of charge. Freezing the electrochemical state of the battery combined with the low atomic number element imaging at nanoscale interface enables us to characterise the interface between the PC NMC811 and electrolyte in its native state allowing us unprecedented insight into relationship between structure, interface stability and reactivity. This insight can then be used to understand battery material degradation including poorly understood transition metal dissolution and be ultimately applied to design better energy materials.

Next-generation lithium-ion batteries for eVTOL, aerospace and high-power applications require cells with low impedance, fast-charging ability and stable operation at low temperatures. Silicon anodes are becoming the new industry standard as they offer exceptional performance and capacity; however, their degradation mechanisms under high-power cycling remain poorly understood.

In this work, we characterise the Molicel P50B 21700 cylindrical cell and provide a parameterised dataset for multi-scale modelling. This study combines (1) multi-temperature diagnostics (25, 15, 5 and -5 °C), including pulse testing, with corresponding (2) long-term cycling to 80% SOH at ~900 cycles, (3) teardown-based verification pathways to understand the processes within the cell, and (4) chemical and structural analysis of the electrodes in the pristine and cycled states.

The positive electrode is polycrystalline NCA. The negative electrode is a bi-component graphite-silicon-carbon composite designed for stability. This material is compared to other silicon materials to assess expansion and performance. Throughout all temperature conditions, the cell maintains consistent capacity and pulse performance. Low temperature (-5 °C) capacity loss is minimal, with 95% retention at C/3 before HPPC testing. At -5 °C, the HPPC resistance increases substantially, ~ 98% higher compared to 25 °C, yet the cell shows stable pulse performance and a controlled temperature rise, benefiting cell operation.

This comprehensive electrochemical, physicochemical, and thermal analysis provides insight into the P50B’s material behaviour under high-power conditions. These findings are directly relevant for manufacturers aiming to validate and model next-generation anode performance, supporting improved prediction and safer use of these cells.

The electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) is a highly sensitive technique for probing metal plating/stripping, enabling real-time quantification of mass changes and interphase viscoelasticity.[1] In this presentation, we employ operando EQCM-D combined with hydrodynamic spectroscopy to investigate Mg and Zn deposition and dissolution processes.[2,3] For magnesium systems, we demonstrate that chloride content and electrolyte stability critically govern the evolution of the passivation layer at the negative electrode. Continuous tracking of mass and mechanical properties reveals dynamic restructuring of the Mg electrode/electrolyte interphase during cycling, highlighting how chloride-rich environments suppress blocking films and facilitate more reversible Mg plating. Using the same methodology, we further resolve distinct growth regimes during Mg electrode/electrolyte interphase formation and correlate interphase softness, mass accumulation, and electrochemical reversibility. Extending these insights to zinc, we show that indium-salt additives can effectively manipulate horizontal Zn nucleation and deposition, enabling stable anode-free Zn metal operation.[4] Overall, these works establish operando EQCM-D as a powerful platform for decoding interphase dynamics and guiding electrolyte and additive design for next-generation Mg and Zn batteries.

Potassium metal batteries (PMBs) hold great promise for next-generation, sustainable batteries due to economic advantages including the cost-effectiveness of K sources and the elimination of critical elements (e.g., Li, Co, Ni) and (electro)chemical advantages including the low redox potential of K⁺/K, the faster K⁺ transport in electrolytes, and the lower desolvation energy at the electrode/electrolyte interface. The challenge to develop PMBs largely comes from K metal anodes – K dendrite growth and unstable solid-electrolyte interphase (SEI) during repetitive plating/stripping cycles, which can cause rapid performance degradation and safety issues. In this talk, I will first talk about the crucial role of lab approaches of processing K metal anodes, reflected by the optimization of the K metal surface properties through K processing methods and how they amplify the benefits of a robust SEI via tuning the electrolyte concentration. I will then discuss another investigation to improve K plating/stripping - creating surface nanotexture on substrates. This is guided by considering the work of adhesion (W_adh) at the K/substrate interface, and we propose this thermodynamic term as a proper descriptor for designing K plating/stripping substrates. Finally, I will show that our investigations enable energy dense PMBs (coin cells) by pairing K metal anodes with high-loading cathodes.

Medium-temperature molten salt battery (<200℃) is a unique electrochemical energy storage device that uses the low melting point inorganic molten salts as electrolytes, features with high electrochemical kinetics and ionic conductivity. The Metal Chlorides-Graphite battery that we proposed is a novel medium-temperature molten salt battery, in which the reversible intercalation/de-intercalation of chloroaluminate ion in graphite interlayers and the solid-phase oxidation/reduction of metal chlorides (MCl2 oxidized)- metal and NaCl (reduced) were used as the positive and negative electrode reactions, and the corresponding electrochemical system has the characteristics of low cost and high safety. Existed researches have shown that metal chlorides such as Fe/FeCl₂, Ni/NiCl₂, and Zn/ZnCl₂ all exhibit excellent electrochemical performances when applied as the anode materials. In the Fe/FeCl2-graphite battery, the obtained Fe/FeCl₂-EAE-1.4V electrode exhibits excellent electrochemical reversibility (over 7000 cycles). Scale up to 150 mAh cell, the capacity remains 155.2 mAh after 1000 cycles, with capacity retention rate of 94.5%. The 10 wt% Ni/NiCl₂-C anode prepared by pre-added metallic nickel and carbon coating shows the specific capacity of 330 mAh·g⁻¹, and the operating temperature for corresponding Ni/NiCl2-graphite molten salt battery is 95℃.

Solid electrolyte-based batteries are seen as a new breakthrough technology to exceed by 50% the energy density of current Li-ion batteries, due to the use of lithium metal as negative electrode [1]. Sulfide solid electrolytes, and especially the argyrodite Li₆PS₅Cl, are the most considered candidates for this application, thanks to their good shaping ability and high ionic conductivity (>10^-3 S/cm) [2]. However, they exhibit a narrow electrochemical stability window, causing their oxidation at its interface with most of common positive electrodes [3]. A Li⁺ ions blocking interphase then forms and causes a fast capacity loss that hinders the use of this electrolyte.

The approach of this work is to develop a highly conformal nanometer-thick coating on the Li₆PS₅Cl electrolyte, in order to prevent its decomposition on contact with the positive electrode, while allowing Li⁺ to cross this layer. These coatings are deposited using Atomic Layer Deposition (ALD), with a tool specially designed for powder deposition under pure argon atmosphere. Lithium phosphates (Li_xP_yO_z) coatings were chosen because of their electrochemical stability, ionic conduction and electronic insulation. This deposition is made following the process by Hämäläinen et al. using lithium hexamethyldisilazide (LiHMDS) and trimethyl phosphate (TMP) [4].

Silicon wafers were used as first-approach substrates to characterize the thin film synthesis. Ellipsometry, X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM) confirmed the controlled conformal growth of a Li₃PO₄ material at a rate of 0.6 Å/cycle. After demonstration of the stability of the solid electrolyte in ALD conditions, the first coatings could be synthesised on the targeted powder substrate. STEM-EDX imaging and XPS analysis revealed that the expected Li₃PO₄ layer was successfully obtained at various thicknesses on all particles. Together with electrochemical impedance spectroscopy (EIS), these characterizations provide valuable insights for a further integration of this coated argyrodite into all-solid-state-batteries.

Zn-based energy storage systems (Zinc-ion Batteries (ZIBs) and capacitors (ZIC) and Rechargeable Zinc-Air Batteries (RZABs)) have emerged as promising alternative for large-scale and stationary applications. Thus, a huge number of investigations have been lately dealt with this technology, trying to tackle the main drawbacks of these technologies[1,2]. Among these, the intrinsic thermodynamic instability of the Zn metal anode in aqueous solutions is a key problem that needs urgent resolution. This fundamental flaw drives critical parasitic side reactions, which together with dendritic growth, severely degrade battery performance limiting cyclability and shelf life. This has made evident the need to engineer electrolytes that can mitigate the Zn anode issues while allowing cathode materials to perform at the required level. While both chemistries face similar problems on the anode, the approach taken for each is quite different. While for ZIBs the composition of the electrolyte has been tuned and modified from dilute ZnSO₄ all the way to water-in-salt formulations[3], the study of organic additives in 6 M KOH has been the dominant strategy in RZABs. A relatively recent trend has focused on the use of near-neutral electrolytes to minimize Zn dissolution and improve stability[4,5]. In this work, the diverse concepts that have been developed in our group for Zn-based technologies are presented. From the use of additives with different functionalities to the implementation of an aqueous-organic water-in-salt electrolytes for Zn-ion capacitors, our results expose the complexity and interaction of many parameters in these systems. Moreover, our attempts to develop a near-neutral Zn(OAc)₂ electrolyte for RZABs will be described, including the use of in-situ Raman to understand the effect of additives on Zn electrochemistry. Overall, this study will point out the delicate link between electrolyte, anode stability and cathode performance, as well as the need to develop cost efficient electrolyte to bring Zn energy storage devices to the next level.

Electrochemical ion intercalation is the predominant charge storage mechanism of modern rechargeable batteries. Typically, ions from a liquid electrolyte desolvate at the electrochemical liquid/solid interface before being inserted into the bulk volume of the layered host electrode. This desolvation is associated with an energy barrier. In contrast, emerging solvent co-intercalation reactions circumvent the desolvation step by directly inserting (partially) solvated ions into the electrode. This can result in fast charge transfer kinetics with improved safety and is an avenue to enable more sustainable battery chemistries that may not be feasible for desolvated ions.[1]

However, there is currently little understanding of how co-intercalation reactions can be achieved and regulated. Herein, I will address how the degree of solvation of intercalating ions can be controlled by the nanoconfinement environment of the layered electrode materials.

Specifically, I will present our recent discovery that there is a geometrical threshold of interlayer spacing in bilayered V2O5 electrodes above which solvent co-intercalation from organic, lithium-ion electrolytes takes place.[2] Moreover, I will demonstrate the feasibility of controlling the extent of water co-intercalation from aqueous zinc-based electrolytes into V2O5 via tuning the nanoconfining interlayer chemistry from hydrophilic to hydrophobic.[3] Finally, I will showcase how the degree of electrolyte confinement in layered titanates[4] can tune the electrochemical charge storage mechanism from battery-like to capacitor-like.

Lithium metal is considered the most promising anode materials for next-generation high energy density batteries (e.g., solid state batteries, Li metal batteries, Li-sulphur batteries, Li-oxygen bateries), benefiting from its very high theoretical capacity (3860 mAh/g) and very low reduction potential (-3.04V). However, the formation and growth of Li dendrite during the repeated charge and discharge process cause significant capacity fade, short circuit, and fatal failure of batteries [1,2]. The safety of Li batteries can be enhanced by modification of the copper current collector and introduction of interlayer materials, to alter the Li nucleation process and suppress dendrite formation at the metal anode-electrolyte interfaces [3,4].

In this talk, I will introduce our efforts in using computational modelling to help design the metal anode-electrolyte interfaces. First-principle density functional theory calculations are used to investigate Li deposition on 19 interlayer metals [4]. A relationship between the Li deposition overpotential and diffusion barriers is established to help identify interlayer metals and alloys that can enable efficient Li deposition. We also collaborate with experimental partners to design a Sn-modified copper substrate, which forms alloying reaction with Li to yield a deposition interlayer composed of Sn and Li-Sn intermetallics that regulates both Li diffusivity and adsorption during initial deposition, leading to enhanced battery performance. Finally, we combine fine-tuned machine-learning interatomic potentials (MLIP) with large-scale molecular dynamics (MD) simulations to resolve the atomistic pathways of lithium alloying and crystallization on Cu and interlayer metals. Zn and Mg show alloy-mediated crystallization process to enhance lithium diffusion and structural uniformity, whilst the Li nucleation on Cu and the formation of intermetallic alloys with Bi are revealed. These results are validated by experimental observations through scanning electron microscopy, X-ray diffraction, atomic force microscopy, and time-of-flight elastic recoil detection corroborates the predicted alloying and phase evolution. The MLIP enhanced MD simulations are also performed for metal anode-solid state electrolytes (SSEs), revealing the formation of different interphase compounds when different SSEs and different interlayer metals are used. Our modelling framework can help design metal interlayers for regulating lithium nucleation and enabling safe operation of next-generation lithium batteries.

Solid-state batteries face persistent challenges arising from sluggish ion transport in solids and interfacial instability at solid–solid contacts. This presentation focuses on in situ polymerized electrolyte strategies for stabilizing interfaces and enabling efficient ion transport in solid-state and quasi-solid-state battery architectures. In particular, we examine enthalpy-driven copolymerization pathways leading to quasi-solid-state poly-DOL electrolytes that form conformal, self-limiting interphases directly at electrode–electrolyte interfaces. These in situ-formed polymers combine mechanical compliance with chemical passivation, mitigating interfacial degradation, contact loss, and chemo-mechanical mismatch during cycling. The polymerization process further enables intimate interfacial contact without external pressure or high-temperature processing, improving manufacturability and scalability. This approach is complemented by the integration of halide solid electrolytes with computationally predicted, chemically stable interlayers that suppress parasitic reactions and broaden electrochemical stability windows. Emphasis is placed on establishing simple, transferable design principles that connect first-principles modeling, molecular design, and high-throughput screening workflows. Together, these strategies provide a unified framework for engineering robust interfaces and ion-conducting pathways, ultimately enabling practical, scalable, and durable solid-state battery architectures.