Lithium Stripping Research Articles

High-Performance Dendrite-Free Lithium Metal Anode Based on Metal-Organic Framework Glass.

The performance of lithium metal batteries is severely hampered by uncontrollable dendrite growth and volume change within the anode. This work addresses these obstacles by introducing a novel strategy: applying an isotropic and internal grain-boundary-free layer, specifically, a metal-organic framework (MOF) glass layer with nano-porosity onto the electrochemically plated lithium metal anode. Both ab initio and classical molecular dynamics simulations indicate that the MOF glass layer makes the lithium transport smooth and uniform via its internal monolithic and interfacial advantages. This MOF glass layer with the fast and more uniform lithium diffusion in the monolithic interior and its interface enables dendrite-free lithium plating and stripping through surface confinement effect and interfacial effect. When employed in symmetric batteries, the achieved Li metal anode can operate over 300h at 1mAcm-2. The full batteries matched with LiFePO4 exhibit high capacity (148mAhg-1), excellent rate performance (61mAhg-1 at 5C), and outstanding cycling stability (with capacity retention of ≈90% after 1000 cycles). The full batteries matched with high-voltage LiCoO2 also show superior performances. Therefore, the strategy of utilizing a MOF glass layer enables the development of high-performance lithium metal anodes.

Operando insights into ammonium-mediated lithium metal stabilization: surface morphology modulation and enhanced SEI development

Lithium-ion batteries (LiBs) with graphite as an anode and lithiated transition metal oxide as a cathode are approaching their specific energy and power theoretical values. To overcome the limitations of LiBs, lithium metal anode with high specific capacity and low negative redox potential is necessary. However, practical application in rechargeable cells is hindered by uncontrolled lithium deposition manifesting, for instance, as Li dendrite growth which can cause formation of dead Li, short circuits and cell failure.The electrochemical behaviour of a protic additive (NH4PF6) in a carbonate-based electrolyte has been investigated by operando confocal Raman spectroscopy, in situ optical microscopy, and X-ray photoelectron spectroscopy, elucidating its functional mechanism. The ammonium cation promotes a chemical modification of the lithium metal anode-electrolyte interphase by producing an N-rich solid electrolyte interphase and chemically modifying the lithium surface morphology by electrochemical pitting. This novel method results in stable lithium deposition and stripping by a decreasing the local current density on the electrode, thus limiting dendritic deposition.

Enhanced performance of lithium metal batteries via cyclic fluorinated ether based electrolytes

To address the challenges associated with applying high-voltage cathodes in lithium metal batteries (LMBs) there is a need for new electrolytes enabling stable interphases at both electrodes. Here we attack this by using a dioxolane-derived cyclic fluorinated ether, 2,2-bis(trifluoromethyl)-1,3-dioxolane (BTFD), as a fluorinated diluent to a 1,2-dimethoxyethane (DME) based electrolyte. The cells using the resulting BTFD-based electrolytes exhibit higher Coulombic efficiencies for lithium stripping and plating as compared to those using the non-fluorinated ether-based electrolyte. This originates from the reduced formation of ‘dead Li’ at the anode, as shown by using electrochemical impedance spectroscopy (EIS). In practice, the BTFD-based electrolytes are shown to improve the performance of Li||NMC cells, which is due to the formation of a predominantly inorganic cathode electrolyte interphase (CEI) that suppresses the cathode degradation during cycling. We used X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM) to characterize the CEIs’ overall composition and structure. To obtain more details on the CEI speciation, Raman and nuclear magnetic resonance (NMR) spectroscopies were employed, assisted by molecular level computations. Overall, we demonstrate how the very design of the electrolyte composition influences the performance of LMBs.

Diphenylphosphoryl Azide as a Multifunctional Flame Retardant Electrolyte Additive for Lithium-Ion Batteries

Graphite anode materials and carbonate electrolyte have been the top choices for commercial lithium-ion batteries (LIBS) for a long time. However, the uneven deposition and stripping of lithium cause irreversible damage to the graphite structure, and the low flash point and high flammability of the carbonate electrolyte pose a significant fire safety risk. Here, we proposed a multifunctional electrolyte additive diphenylphosphoryl azide (DPPA), which can construct a solid electrolyte interphase (SEI) with high ionic conductivity lithium nitride (Li3N) to ensure efficient transport of Li+. This not only protects the artificial graphite (AG) electrode but also inhibits lithium dendrites to achieve excellent electrochemical performance. Meanwhile, the LIBS with DPPA offers satisfactory flame retardancy performance. The AG//Li half cells with DPPA-0.5M can still maintain a specific capacity of about 350 mAh/g after 200 cycles at 0.2 C. Its cycle performance and rate performance were better than commercial electrolyte (EC/DMC). After cycling, the microstructure surface of the AG electrode was complete and flat, and the surface of the lithium metal electrode had fewer lithium dendrites. Importantly, we found that the pouch cell with DPPA-0.5M had low peak heat release rate. When exposed to external conditions of continuous heating, DPPA significantly improved the fire safety of the LIBS. The research of DPPA in lithium electrolyte is a step towards the development of safe and efficient lithium batteries.

In Situ NMR Verification for Stacking Pressure‐Induced Lithium Deposition and Dead Lithium in Anode‐Free Lithium Metal Batteries

AbstractAnode‐free lithium metal batteries have emerged as strong contenders for next‐generation rechargeable batteries due to their ultra‐high energy density. However, their safety and life span are insufficient because of the easy generation of dendrites and dead lithium during lithium plating and stripping. Understanding the formation mechanism for lithium dendrites and dead lithium is essential to further improve battery performance. By employing in situ solid‐state nuclear magnetic resonance (NMR) spectroscopy, the influence of stacking pressure on dendritic behavior and dead lithium is systematically investigated. At 0.1 MPa, lithium dendrite is rapidly formed, followed by a linear increase of dead lithium. High stacking pressure not only causes lithium metal to fracture but also leads to form dendrites and dead lithium at the fracture site. At 0.5 MPa stacking pressure, the least quantity of dead lithium is attained, and the growth pattern of dead lithium is exponential growth. The exponential growth pattern is distinguished by the high growth of dead lithium early in the battery cycle and essentially no growth later in the cycle. As a result, it is believed that efficient suppression of dead lithium generation early in battery cycling can play a critical role in improving battery performance.

An MPM-Based Phase-Field Simulation of Plating and Stripping of Lithium with a Solid Electrolyte Interphase

A methodology for performing phase-field simulations of plating and stripping in the presence of a solid electrolyte interphase (SEI) is presented and applied to a lithium metal electrode. Material point method (MPM) simulations are performed assuming a homogeneous SEI layer and are compared with experiment. Results are consistent with experiment for two electrolytes and confirm the dominance of the SEI layer in determining cell impedance. Notably, in some instances, the SEI potential drop greatly affected activation overpotential, differing from the applied potential. To accurately depict stripping current vs potential for SEI-free systems, the model considered non-ideal electrolyte effects: concentration-dependent salt activity coefficient, salt diffusion coefficient, and electrolyte conductivity. Conversely, systems with SEI layers displayed minimal non-ideal concentration-related electrolyte effects due to impedance originating primarily from the SEI. In plating scenarios, low SEI salt concentration negated the need for non-ideal SEI effects. However, for stripping, non-ideal salt-concentration dependent SEI effects were crucial in reproducing experimental behavior, owing to high salt concentration at the electrode/SEI interface.

Optimized lithium deposition on Ag nanoparticles-embedded TiO2 microspheres: a facile spray pyrolysis approach for enhanced lithium metal anode

TiO2 microspheres with Ag nanocrystals were synthesized via spray pyrolysis process. TiO2-Ag showed excellent reversible lithium deposition and stripping properties. TiO2-Ag electrode paired with cathode showed excellent electrochemical properties.

Interface Welding via Thermal Pulse Sintering to Enable 4.6 V Solid‐State Batteries

AbstractNASICON‐type Li1.3Al0.3Ti1.7(PO4)3 (LATP) is one of the most promising solid‐state electrolytes (SSEs) to achieve high‐energy‐density solid‐state batteries (SSBs) due to its high ionic conductivity, high‐voltage stability, and low cost. However, its practical application is constrained by inadequate interfacial compatibility with cathode materials and significant incompatibility with lithium metal. In this work, a cost‐effective interface welding approach is reported, utilizing an innovative thermal pulse sintering (TPS) to fabricate LATP‐based solid‐state batteries. Initially, the rapid thermal pulses enhance the ionic conductivity of LATP SSE by inducing selective growth of LATP nanowires, effectively occupying interparticle voids. Additionally, this process results in the formation of a dense layer (GCM) comprising graphene oxide, carbon nanotubes, and MXene with a controlled Li+ transport pathway, facilitating lithium stripping and plating processes. Moreover, these thermal pulses facilitate the interfacial fusion between LATP and cathode materials, while avoiding undesired phase diffusion. As a result, SSBs with a LiCoO2 cathode deliver favorable cycle stability at 4.6 V, marking significant progress. This facile interface welding strategy represents a substantial step toward high‐energy‐density SSB development.

Effect of Water As an Electrolyte Additive for Lithium Plating

Li metal anode is generally referred to as the “holy grail” of battery technology as it can deliver the highest possible energy density, which double the capacity of state of art graphite based cells1. At the heart of this advanced technology is the process of continuous plating and stripping of lithium during the cycling of the battery. Owing to the highly reactive nature of Li, this is a complicated process with several challenges2 during both plating (for e.g., dendrite formation and growth, dead lithium, continuous interface/interphase change, short circuit etc.) and stripping (void formation, pitting, broken interface/interphase layers etc.). The electrode architecture, choice of electrolyte, solid electrolyte interphase (SEI) formation, operating conditions etc. are key factors that determine overall stability of Li metal anodes. These issues get magnified when using liquid electrolytes, where continuous SEI formation leads to dead Lithium (electrically insulating) accumulation.In general, most solvents and salts employed for Li ion cells contain some amount of water as impurity even after maintaining strict conditions to keep them anhydrous. The presence of trace amount of water in combination with fluorine from either salt (LiPF6. LiTFSI, LiFSI) or solvent additives FEC can then lead to in-situ formation of HF, which has detrimental effects on Li plating. However, recently many groups have shown the beneficial effect of small amount of water as additives for Li metal anodes3,4. However, the exact mechanism of functioning of H2O as an additive is not very clear. This is partly because the formation of SEI is quite complex, especially when film forming type solvents/additives are present in the electrolyte addition to trace amounts of water.It is thus important to investigate the nucleation and growth of Li during the initial stages of plating and understand how the presence of H2O in the electrolyte affects the morphology andthe chemical nature of the deposited Li metal films. In this direction, we choose tetraglyme (4G), which is a relatively non-labile solvent towards Li plating conditions (reduction potential ~ 1.49 vs Li+/Li), as the solvent to avoid any contribution from the solvent itself on SEI formation. We then systematically study the effect of H2O on Li plating; both stand alone and in presence of various film forming additives. We show that water can indeed drastically affect the morphology and electrochemical properties of the deposited Li. Acknowledgement: This work is part of FUGELS (Functionally Graded Electrodes for Long-Life Lithium-Sulfur Batteries) project, which is a cconsortium of researchers from University of Hasselt, University of Gent, University of Antwerp, VITO, IMEC and IMOMEC.

Improving Cycling Performance of Anode-Free Lithium Metal Batteries By Electrolyte Design

The anode-free lithium metal battery (AFLMB) is gaining attention due to its straightforward yet innovative cell configuration. However, the direct plating and stripping of lithium on the copper current collector presents challenges in material design and cell fabrication. Uncontrolled lithium growth and dendrite formation are common in these challenging conditions and can result in low coulombic efficiency. In this presentation, we summarize recent efforts to develop new electrolytes for high-voltage applications based on AFLMB protocols, including concentrated dual-salt and locally concentrated electrolytes, as well as additives. The solvation structure and corresponding interfacial analysis are significant factors in this development. Additionally, we aim to establish a titration-based method to estimate dead and inactive lithium in various electrolytes, which could facilitate the quick screening of various electrolyte candidates and offer further insight into the fundamentals of lithium growth and solid-electrolyte interface formation.

Lithium Plating and Stripping Behaviors of Anode-Free Solid-State Lithium-Ion Batteries Depending on Composition of Protective Layer

Solid-state lithium-ion batteries without anode active materials are one of the most promising types of energy storage methods to improve the energy density of solid-state lithium-ion battery. In this work, we compared lithium plating and stripping behaviors of anode-free solid-state batteries with various anode compositions by means of electrochemical and analytical characterization methods. We found that the electrochemical performance of solid-state lithium ion battery without anode active material is highly dependent on the composition of protective layer. The morphological changes in the anode during lithium plating and stripping will be presented in more detailed in the presentation.

Surface Modification of Li Metal Anodes Using Ag Nanoparticles and PVDF: An EC-AFM Investigation

Lithium metal has captured interest as an attractive anode material for next-generation batteries due to its extremely large theoretical specific capacity (approximately 3800 mAh/g) and low reduction potential. However, challenges related to uncontrolled lithium plating and stripping, unwanted side reactions, and uneven lithium growth on the surface (top growth) contribute to safety concerns and poor cycling performance, hindering the widespread application of lithium metal batteries [1]. In this study, we conducted electrochemical atomic force microscopy (EC-AFM) to investigate the lithium deposition behavior of silver nanoparticles (Ag NPs) on lithium metal substrate surfaces. Kelvin probe force microscopy (KPFM) revealed that Ag NPs possess a lower surface potential than the lithium substrate surface, providing reaction sites for lithium deposition during the plating process. This leads to the formation of a lithium-silver (LiAg) solid solution instead of pure lithium metal, effectively mitigating the issues associated with uncontrolled Li plating. The LiAg alloy phase exhibited improved reversibility compared to bare lithium metal, resulting in improved cycling performance [2]. Additionally, we found that coating the lithium metal surface with a layer of polyvinylidene fluoride (PVDF) promotes bottom-up lithium deposition while physically suppressing dendrite formation. As an ionically conductive but electronically resistant polymer, PVDF allows Li+ transport while suppressing lithium deposition on the top surface [3], reducing safety issues associated with dendrite formation during lithium deposition. Our EC-AFM results reveal the morphological evolution of Ag NPs and PVDF on lithium metal during the plating and stripping process, offering preliminary insights into the underlying mechanisms. Based on our investigations, we propose that the combination of Ag NPs and PVDF could potentially be an effective choice for modifying lithium metal surfaces. This approach aims to enable controlled lithium plating and stripping, as well as bottom-up lithium deposition, with the goal of improving safety and cycling performance for anodes in the next generation of high-energy-density lithium metal batteries, focusing on improving safety and achieving long life cycle.[1] H. Park et al, Adv. Energy Mater. 2021, 11, 2003039.[2] S. Jin et al, J. Am. Chem. Soc. 2020, 19, 8818.[3] J. Yun et al, ACS Energy Lett. 2020, 5, 3108.

(Invited) Controlling Nucleation and Growth of Lithium Metal for High Performance Batteries

The cycling behavior of the lithium metal anode determines the life time of lithium metal batteries when paired with common oxide or polymer-based sulfur (e.g., sulfurized polyacrylonitrile, SPAN) cathodes. Significant progress has been made on electrolyte engineering to improve the morphology of lithium metal. Those electrolytes with high concentration or weakly solvating solvents have shown most promise due to the promotion of anion-cation ion pairing and the reduction in desolvation energy.On the other hand, gaining control of the lithium nucleation and growth remains challenging. We have shown recently that the substrate plays an important role in dictating lithium nucleation. An in-situ formed Fe/LiF substrate has been shown to lead to uniform lithium nucleation and fast lithium surface transport, resulting in the formation of hexagonal lithium single crystal seeds. These faceted seeds promote subsequent dense lithium growth even after repeated cycles. Importantly, the growth of porosity and the pulverization are effectively mitigated.In this talk, we systematically analyze the factors that contribute to the single crystal growth and strive to quantify the different kinetic processes (surface transport, electrolyte transport, bulk diffusion, charge transfer) that collectively determine the seed growth behavior. On the other hand, we will describe our implementation of the nucleation control mechanism on a lithium metal foil so that these electrodes can be paired with non-lithium containing cathodes. We have found that adding nucleation agents to the lithium metal mitigates the formation of random pits during lithium stripping and subsequently promote the formation of dense lithium layer on top. As a result, a Li/SPAN battery with an areal capacity of > 7 mAh cm-2 has demonstrated stable cycling for over 200 cycles. Adding nucleation control measures to lithium metal is thus a promising approach to improve the cycle life of lithium metal batteries.

Nanotwinned Structure in Copper Affects Lithium Deposition Behavior at Electrolyte-Electrode Interface in Anode-Free Lithium Metal Battery

Anode-free lithium metal battery (AFLMB) is one of new promising energy storage systems. In contrast to lithium-ion battery, the negative electrode of AFLMB does not contain any active materials, resulting in a two-fold increase in energy density. As a result, the charging mechanism on the negative electrode in AFLMB is based on electrodeposition of lithium, rather than intercalation of lithium ions. Unfortunately, that causes a series of problems, such as lithium dendrite formation, volume expansion, broken SEI and dead lithium accumulation, leading to the low cycling stability of AFLMB. Consequently, interfacial characteristics of the negative electrode (usually copper) play a critical role in determining the morphology of lithium deposits which largely affects the issues mentioned above. Understanding the mechanism of lithium electrodeposition across the electrode-electrolyte interface is crucial to design a better copper electrode for long-cyclability AFLMB.The interfacial characteristics of copper are mainly influenced by crystal phase, surface roughness and defects. While the effects of crystal phase and surface roughness on lithium electrodeposition have been extensively studied, the role of micro-scale defects has been seldom discussed, despite their potential to strongly influence the surface properties of copper. Therefore, this work focuses on elucidating the elementary process about how the defects on copper affect the lithium nucleation and subsequent growth. Specifically, we use (111)-nanotwinned and (111)-preferred orientation copper foils with the same surface roughness to conduct a series of electrochemical measurements. The presence of nanotwin structure can reduce the grain boundary and atomic step density, a type of the defects with high surface energy, on the copper. Before lithium electrodeposition, solvents and anions in an electrolyte adsorb on the electrode-electrolyte interface to form the electric double layer. During this process, the atomic steps with high surface energy on copper can establish strong adsorption with the substance in the electrolyte. The solvents adsorbed on the defects may hinder the reduction of anion. Accordingly, the (111)-nanotwinned Cu foil with fewer defects induces the formation of LiF-rich solid electrolyte interphase (SEI), which is beneficial to the transportation of lithium ions. In cyclic voltammetry test, the (111)-nanotwinned Cu foil exhibits higher reduction current density of the precipitation of LiF (Fig. 1).For lithium electrodeposition, during the initial stage, lithium adatoms tend to adsorb on the defects with high surface energy on the copper surface, where other adatoms accumulate to form stable nucleus. Subsequently, the nucleus on each nucleation sites might have different growth direction and crystal phase, resulting in a lot of independent lithium grains. In other words, compared to the (111)-preferred orientation substrate, the (111)-nanotwinned Cu foil with less nucleation sites provides more space for the nucleus to grow in 2-D direction, which leads to the lower nucleation overpotential (Fig. 2 a). That result also facilitates the formation of larger lithium grains with smaller surface area exposed to the electrolyte (Fig. 3). As shown in Figure 2 (b), quasi-steady state over-potential of Li plating on the (111)-nanotwinned Cu is generally larger than that on the (111)-preferred orientation Cu foil, which has been ascribed to the high local current density on larger lithium grains. The quasi-steady state overpotential of Li plating on the (111)-preferred orientation Cu foil gradually increased with the cycle number, which might be attributable to the relatively unstable SEI and the accumulation of dead lithium with the GCD cycling. Furthermore, the (111)-nanotwinned Cu foil always exhibits a lower quasi-steady state overpotential of lithium stripping in comparison with the (111)-preferred orientation substrate at each cycle, probably resulting from the uniform Li deposit and the special LiF-rich SEI formation due to the nanotwinned structure. In the cycling stability test (Figure 2 c), for the Cu//Li cell using the (111)-nanotwinned Cu foil, the coulombic efficiency was kept being around 90% in this 160-cycle test. However, for the Cu//Li cell using the (111)-preferred orientation Cu foil, the coulombic efficiency is generally lower than that of the cell using the (111)-nanotwinned Cu foil at the cycle number > 15. In addition, the coulombic efficiency starts to obviously decay at the 135th cycle and becomes lower than 5% at the 160th cycle.To sum up, we proposed a mechanism about how the defects affect the reaction at electrode-electrolyte interface. The nanotwinned columnar grains reduces the atomic density on the copper surface, which effectively reduces the formation of lithium dendrite, the accumulation of dead lithium and broken SEI. The (111)-nanotwinned Cu foil is proved to be a superior substrate for lithium deposition and stripping, significantly improving the Li+/Li redox reversibility and cycling stability. Figure 1

Influence of Lithium Diffusion into Copper Current Collectors on Lithium Electrodeposition in Anode-Free Lithium-Metal Batteries

With increasing demands for lithium-based batteries that have higher energy densities, access to better negative electrode materials becomes crucial. Lithium metal which has a very high theoretical specific capacity, a very low standard potential and a very low density can be considered one of the best negative electrode materials for next-generation lithium-based batteries. In order to fully exploit the merits of lithium metal, a cell configuration in which lithium is directly electrodeposited (and then stripped) on (from) the negative electrode current collector (i.e., copper foil) is essential. Such “anode-material-free” (or ”anode-free”) lithium-metal batteries can have significantly higher gravimetric and volumetric energy densities than conventional graphite-based lithium-ion batteries. However, poor control of the lithium electrodeposition directly on the copper current collector, especially in conventional carbonate electrolytes, limits the development of such batteries. It is therefore essential to improve the understandings of the lithium electrodeposition, especially its nucleation process, and the interactions between lithium and the copper substrate.According to the classical electrodeposition theory, a larger overpotential will lead to a decrease in both the critical free energy for the nucleation and the critical radius of the nuclei, which should facilitate the nucleation process since more clusters can reach the critical radius required to form stable nuclei with a lower energy barrier. The concept was utilized via the application of a potentiostatic nucleation pulse to attain two-dimensional instantaneous lithium nucleation on lithium-metal electrodes in a previous study by Rehnlund et al.[1] Using such a strategy should also provide some insights into the lithium nucleation on copper substrates. In addition, it is also important to consider interactions between lithium and the copper substrate. A study, in which Lv et al.[2] used operando neutron diffraction to track the spatial distribution of lithium during lithium electrodeposition and stripping on copper, revealed that some lithium was actually taken up by the copper substrates most likely via the grain boundaries during the electrodeposition. In other studies by Rehnlund et al., the results also showed that lithium can diffuse into copper and that the effect of this diffusion can be readily seen after electrodepositing a small amount of lithium (as would be the case during the lithium nucleation stage).[3,4] However, the relation between such a lithium diffusion behavior and the lithium nucleation on copper substrates is not clearly studied.With a series of electrodeposition experiments, we demonstrate that it is highly possible that the lithium diffusion into the copper substrate can influence the nucleation process. Due to the presence of such diffusion, small lithium clusters and nuclei may be lost during the nucleation process, which makes it difficult to obtain a larger number of lithium nuclei with a homogeneous distribution on the copper surface. This then leads to inhomogeneous lithium electrodeposits with poor morphologies. It is, however, demonstrated that the nucleation of lithium on copper can be significantly improved if an initial chemical prelithiation of the copper surface is performed. This prelithiation saturates the copper surface with lithium and hence decreases the influence of lithium diffusion via the grain boundaries. In this way, the lithium nucleation can be made to take place more homogenously on the copper surface, especially when a short potentiostatic nucleation pulse that can generate a large number of nuclei is used.[1] D. Rehnlund, C. Ihrfors, J. Maibach, L. Nyholm, Mater. Today 21 (2018) 1010–1018.[2] S. Lv, T. Verhallen, A. Vasileiadis, F. Ooms, Y. Xu, Z. Li, Z. Li, M. Wagemaker, Nat. Commun. 9 (2018) 1–12.[3] D. Rehnlund, F. Lindgren, S. Böhme, T. Nordh, Y. Zou, J. Pettersson, U. Bexell, M. Boman, K. Edström, L. Nyholm, Energy Environ. Sci. 10 (2017) 1350–1357.[4] D. Rehnlund, J. Pettersson, K. Edström, L. Nyholm, ChemistrySelect 3 (2018) 2311–2314.

Cu Foil Modification By Ag Inkjet Printing for Improved Li Plating in Anode-Free Li Batteries

The rush in the development of new generation of lithium-ion batteries (LIB) is focused on enhancing the specific energy of batteries by employing innovative materials and manufacturing techniques. Anode-free lithium metal batteries (AFLBs) are an emerging technology that can almost double the specific energy of LIBs by eliminating the conventional graphite negative electrode or excess lithium metal 1. However, AFLBs are well-known to suffer of fast capacity decay due to the poor lithium plating and stripping efficiency process associated to the typical porous growth of Li during charge 2. Tuning the interfacial electrochemistry was widely demonstrated to be one the most performing key to enable efficient and smooth Li deposition. In this regards, functional coatings of metals as Sn, Al, Zn and Ag have been widely demonstrated to dramatically improve the quality of Li plating process respect to the neat Cu foil substrate, by forming lithium-rich alloys that provide minimum Li nucleation overpotentials 3. Inkjet printing (IJP) could be a viable technique for electrode fabrication in LIBs manufacturing, being a quick, easy and scalable technology able to deposit both thin film and patterned structures 4. However, very poor attention has been paid so far to the potentiality of IJP for Cu modification for improved Li plating in AFLBs.In this work, we employed a Fujifilm Dimatix inkjet printer to achieve “lithiophilic” coatings of Ag nanoparticles deposited on a Cu foil. In particular, potenziodynamic and galvanostatic electrochemical test were employed to investigate the effect of the Ag printed structures on the Li nucleation overpotential. Ex-situ morphological analysis by electron scanning microscopy (SEM) were usefully employed to investigate the surface evolution of the printed electrodes during lithium alloying and plating. In particular, the effect pf patterned Ag structured rather than fully coated Cu was investigated, revealing that patterning can provide more mechanically robust electrode and efficient catalytic sites for Li electrodeposition respect to fully coated inkjet printed electrodes. Bibliography L. Lin et al., Advanced Materials, 34, 2110323 (2022).L. Su and A. Manthiram, Small Structures, 3, 2200114 (2022).X. Gu, J. Dong, and C. Lai, Engineering Reports, 3, e12339 (2021).P. Viviani, E. Gibertini, F. Iervolino, M. Levi, and L. Magagnin, Journal of Manufacturing Processes, 72, 411–418 (2021).

Forming Artificial Solid-Electrolyte-Interfaces between Lithium Metal Anodes and Halide and Sulfide Solid Electrolytes in All-Solid-State-Batteries Via Spatial-Atomic-Layer-Deposition

Increasing need in energy density and safety of current lithium-ion batteries has resulted in a search for next generation battery technologies1,2. All-solid-state-batteries (ASSBs) could answer these needs owing to the use electrode materials with higher capacities and potential difference, and by replacing flammable liquid electrolytes with solid electrolytes3,4. ASSBs using inorganic sulfide and halide solid electrolytes in particular have drawn a lot of attention as the electrolytes have very high RT ionic conductivities (>10-3 S.cm-1)5–7. Nevertheless, they suffer from issues related to electro-chemical and chemo-mechanical stabilities at electrode – electrolyte interfaces7,8. One promising approach to mitigate this issue is depositing an artificial solid-electrolyte-interface (SEI) layer via atomic-layer-deposition (ALD)9–11. In this work, we deposited a variety of artificial layers with different thicknesses and chemistries on the lithium metal anode using spatial ALD. We characterized the bonding within the thin film layer using X-ray photoelectron spectroscopy, and evaluated the stabilizing effect of the artificial SEI layer using electrochemical impedance spectroscopy and galvanostatic lithium plating and stripping methods. We compared the growth of lithium dendrites within the solid electrolyte pellets post-mortem analysis via scanning electron microscopy. J. Janek and W. G. Zeier, Nat. Energy (2023) https://www.nature.com/articles/s41560-023-01208-9.Q. Wang, L. Jiang, Y. Yu, and J. Sun, Nano Energy, 55, 93–114 (2019) https://doi.org/10.1016/j.nanoen.2018.10.035.J. B. Goodenough and M. H. Braga, Dalt. Trans. (2017) http://xlink.rsc.org/?DOI=C7DT03026F.J. Janek and W. G. Zeier, Nat. Energy, 1, 16141 (2016) http://www.nature.com/articles/nenergy2016141.R. Schlem et al., Adv. Energy Mater., 11, 2101022 (2021) https://onlinelibrary.wiley.com/doi/10.1002/aenm.202101022.S. Ohno et al., Prog. Energy, 2, 022001 (2020) https://iopscience.iop.org/article/10.1088/2516-1083/ab73dd.T. Koç, F. Marchini, G. Rousse, R. Dugas, and J. M. Tarascon, ACS Appl. Energy Mater., 4, 13575–13585 (2021).Y. He, C. Lu, S. Liu, W. Zheng, and J. Luo, Adv. Energy Mater., 9, 1–40 (2019).L. Han, C. Te Hsieh, B. Chandra Mallick, J. Li, and Y. Ashraf Gandomi, Nanoscale Adv., 3, 2728–2740 (2021).J. Liu and X. Sun, Nanotechnology, 26, 24001 (2015) http://dx.doi.org/10.1088/0957-4484/26/2/024001.Y. Jiang et al., Energy Storage Mater., 28, 17–26 (2020) https://doi.org/10.1016/j.ensm.2020.01.019.

Influence of Au, Pt, and C Seed Layers on Lithium Nucleation Dynamics for Anode-Free Solid-State Batteries.

In the concept of anode-free lithium-ion batteries, cells are manufactured with a bare anode current collector where the lithium metal anode is electrochemically formed from the lithium-containing cathode during the first charge cycle. While this concept has many attractive aspects from a manufacturing and energy density standpoint, stable plating and stripping remain challenging. We have investigated gold, platinum, and amorphous carbon as seed layers placed between the copper current collector and the lithium phosphorus oxynitride thin-film solid electrolyte. These layers guide lithium nucleation and improve the plating and stripping dynamics. All seed layers facilitate reversible lithium plating and stripping even at high current densities up to 8 mA cm-2. Of particular note is the amorphous carbon seed layer, which allowed a significant reduction in plating potential from 300 mV to as low as 50 mV. These results underscore the critical role of seed layers in improving the efficiency of anode-free solid-state batteries and open the door to simplified manufacturing of anode-free battery designs.

Nanocrystalline cellulose reinforced poly(ethylene oxide) electrolytes for lithium-metal batteries with excellent cycling stability

Polyethylene oxide (PEO) based polymer electrolytes are still the state of the art for commercial lithium-metal batteries (LMBs) despite their remaining challenges such as the limited ionic conductivity at ambient temperature. Accordingly, the realization of thin electrolyte membranes and, thus, higher conductance is even more important, but this requires a sufficiently high mechanical strength. Herein, the incorporation of nanocrystalline cellulose into PEO-based electrolyte membranes is investigated with a specific focus on the electrochemical properties and the compatibility with lithium-metal and LiFePO4-based electrodes. The excellent cycling stability of symmetric Li||Li cells, including the complete stripping of lithium from one electrode to the other, and Li||LiFePO4 cells renders this approach very promising for eventually yielding thin high-performance electrolyte membranes for LMBs.

Dynamics of lithium stripping on graphite electrodes after fast charging

Dynamics of lithium stripping on graphite electrodes after fast charging