Inorganic Solid-state Electrolytes Research Articles

Hopping Rate and Migration Entropy as the Origin of Superionic Conduction within Solid-State Electrolytes.

Inorganic solid-state electrolytes (SSEs) have gained significant attention for their potential use in high-energy solid-state batteries. However, there is a lack of understanding of the underlying mechanisms of fast ion conduction in SSEs. Here, we clarify the critical parameters that influence ion conductivity in SSEs through a combined analysis approach that examines several representative SSEs (Li3YCl6, Li3HoCl6, and Li6PS5Cl), which are further verified in the xLiCl-InCl3 system. The scaling analysis on conductivity spectra allowed the decoupled influences of mobile carrier concentration and hopping rate on ionic conductivity. Although the carrier concentration varied with temperature, the change alone cannot lead to the several orders of magnitude difference in conductivity. Instead, the hopping rate and the ionic conductivity present the same trend with the temperature change. Migration entropy, which arises from lattice vibrations of the jumping atoms from the initial sites to the saddle sites, is also proven to play a significant role in fast Li+ migration. The findings suggest that the multiple dependent variables such as the Li+ hopping frequency and migration energy are also responsible for the ionic conduction behavior within SSEs.

Halide‐based solid electrolytes: The history, progress, and challenges

AbstractLithium metal solid‐state batteries (LMSBs) have attracted extensive attention over the past decades, due to their fascinating advantages of safety and potential for high energy density. Solid‐state electrolytes (SEs) with fast ionic transport and excellent stability are indispensable components in LMSBs. Heretofore, a series of inorganic SEs have been extensively explored, such as sulfide‐ and oxide‐based electrolytes. Unfortunately, they both have difficulty in achieving a satisfactory balance of conductivity and stability, and oxides suffer from a high impedance of grain boundaries, while sulfides encounter poor stability. Halide‐based solid electrolytes are gradually emerging as one of the most promising candidates for LMSBs due to their advantages of decent room temperature ionic conductivity (>10−3 S cm−1), good compatibility with oxide cathode materials, good chemical stability, and scalability. Herein, research and development of the widely studied metal halide SEs including fluorides, chlorides, bromides, and iodides are reviewed, mainly focusing on the structures and ionic conductivities as well as preparation methods and electrochemical/chemical stabilities. And then, based on typical metal halide solid electrolytes, we emphasize the interface issues (grain boundaries, cathode−electrolyte and electrolyte–anode interfaces) that exist in the corresponding LMSBs and summarize the related work on understanding and engineering these interfaces. Furthermore, the typical (or in situ) characterization tools widely used for solid‐state interfaces are reviewed. Finally, a perspective on the future direction for developing high‐performance LMSBs based on the halide electrolyte family is put out.

Air-stable iodized-oxychloride argyrodite sulfide and anionic swap on the practical potential window for all-solid-state lithium-metal batteries

Among inorganic solid-state electrolytes, argyrodite sulfides are capable candidates for their superb-ionic conductivity, versatility over synthesis, and cost. However, the growth of resistive interphase, limited oxidative stability, and highly-oxophilic nature are limiting factors. Herein, we report iodized-oxychloride argyrodite with robust SEI containing in-situ formed LiI and Li2O upon treating the sulfide via fumy iodine. Sacrificial iodine-induced dendrite suppression capability up to 21 mA cm−2 was achieved. Ultrahigh-lithium compatibility with a high cutoff-capacity of 10 mAh cm−2 was cycled at 10 mA cm−2 for 260 hr. Moreover, durable cycling was performed at 0.1 mA cm−2 for 11,000 h, 2 mA cm−2 for 1000 h, and 6 mA cm−2 for 460 h. Stepwise CV measurement demonstrates enhanced “True practical potential window” stability up to 3.42 V vs. Li/Li+. Cell performance of Li6PS4.8O0.2Cl-5 wt. % I2 with Li-In at 1 C and 3 C has achieved capacity retention of 89.6 % and 89.9 % after 200 and 300 cycles. Outstanding cyclability with Li-metal at 0.4 C with an initial-discharge capacity of 137.27 mAh g−1 was achieved. Enhanced tolerance to moisture with suppressed H2S gas generation was proven by coupling in-situ Raman measurements.

Understanding Electrochemical Reaction Mechanisms of Sulfur in All-Solid-State Batteries through Operando and Theoretical Studies.

Due to its outstanding safety and high energy density, all-solid-state lithium-sulfur batteries (ASLSBs) are considered as a potential future energy storage technology. The electrochemical reaction pathway in ASLSBs with inorganic solid-state electrolytes is different from Li-S batteries with liquid electrolytes, but the mechanism remains unclear. By combining operando Raman spectroscopy and ex situ X-ray absorption spectroscopy, we investigated the reaction mechanism of sulfur (S8 ) in ASLSBs. Our results revealed that no Li2 S8, Li2 S6, and Li2 S4 were formed, yet Li2 S2 was detected. Furthermore, first-principles structural calculations were employed to disclose the formation energy of solid state Li2 Sn (1≤n≤8), in which Li2 S2 was a metastable phase, consistent with experimental observations. Meanwhile, partial S8 and Li2 S2 remained at the full lithiation stage, suggesting incomplete reaction due to sluggish reaction kinetics in ASLSBs.

Realizing high-capacity all-solid-state lithium-sulfur batteries using a low-density inorganic solid-state electrolyte

Lithium-sulfur all-solid-state batteries using inorganic solid-state electrolytes are considered promising electrochemical energy storage technologies. However, developing positive electrodes with high sulfur content, adequate sulfur utilization, and high mass loading is challenging. Here, to address these concerns, we propose using a liquid-phase-synthesized Li3PS4-2LiBH4 glass-ceramic solid electrolyte with a low density (1.491 g cm−3), small primary particle size (~500 nm) and bulk ionic conductivity of 6.0 mS cm−1 at 25 °C for fabricating lithium-sulfur all-solid-state batteries. When tested in a Swagelok cell configuration with a Li-In negative electrode and a 60 wt% S positive electrode applying an average stack pressure of ~55 MPa, the all-solid-state battery delivered a high discharge capacity of about 1144.6 mAh g−1 at 167.5 mA g−1 and 60 °C. We further demonstrate that the use of the low-density solid electrolyte increases the electrolyte volume ratio in the cathode, reduces inactive bulky sulfur, and improves the content uniformity of the sulfur-based positive electrode, thus providing sufficient ion conduction pathways for battery performance improvement.

Review of the Developments and Difficulties in Inorganic Solid-State Electrolytes.

All-solid-state lithium-ion batteries (ASSLIBs), with their exceptional attributes, have captured the attention of researchers. They offer a viable solution to the inherent flaws of traditional lithium-ion batteries. The crux of an ASSLB lies in its solid-state electrolyte (SSE) which shows higher stability and safety compared to liquid electrolyte. Additionally, it holds the promise of being compatible with Li metal anode, thereby realizing higher capacity. Inorganic SSEs have undergone tremendous developments in the last few decades; however, their practical applications still face difficulties such as the electrode-electrolyte interface, air stability, and so on. The structural composition of inorganic electrolytes is inherently linked to the advantages and difficulties they present. This article provides a comprehensive explanation of the development, structure, and Li-ion transport mechanism of representative inorganic SSEs. Moreover, corresponding difficulties such as interface issues and air stability as well as possible solutions are also discussed.

The effect of defects for the ion transport of Li3ScCl6 and Li3InCl6 with the interface of lithium metal anode: A first-principles study

Li3ScCl6 and Li3InCl6 have good ionic conductivity and a wide stable chemical window, which showing great potential in many inorganic solid-state electrolytes. Due to the disordered occupancy phenomenon of the lattice sites between the framework lithium ions and the transported ions. The concentration nonuniformity of lithium ions causes the blocking of mobile ions in the transition metal lithium halide solid electrolyte. However, vacancy defects can cause changes in the charge balance of nonstoichiometric systems, which reducing blocking effects during ion diffusion. In addition, lithium dendrites still exist at the interface between the inorganic solid electrolyte and the lithium metal anode. It can effectively improve the occurrence of interface side reaction because LiF has high interface energy. The effect of vacancy defects for lithium ion migration parameters of Li3ScCl6 and Li3InCl6 at different temperatures are simulated by the first principle. The results showing that lithium ions had better migration and diffusion ability in the structure containing lithium site defects of Li3InCl6. A dual-halide electrolyte interface model was constructed to suppress the growth of Li dendrites on the surface of a Li metal anode. The Li3ScCl6-LiF heterostructure interface can stably control ion transport on the surface of a lithium metal anode.

Surface engineering of inorganic solid-state electrolytes via interlayers strategy for developing long-cycling quasi-all-solid-state lithium batteries

Lithium metal batteries (LMBs) with inorganic solid-state electrolytes are considered promising secondary battery systems because of their higher energy content than their Li-ion counterpart. However, the LMB performance remains unsatisfactory for commercialization, primarily owing to the inability of the inorganic solid-state electrolytes to hinder lithium dendrite propagation. Here, using an Ag-coated Li6.4La3Zr1.7Ta0.3O12 (LLZTO) inorganic solid electrolyte in combination with a silver-carbon interlayer, we demonstrate the production of stable interfacially engineered lab-scale LMBs. Via experimental measurements and computational modelling, we prove that the interlayers strategy effectively regulates lithium stripping/plating and prevents dendrite penetration in the solid-state electrolyte pellet. By coupling the surface-engineered LLZTO with a lithium metal negative electrode, a high-voltage positive electrode with an ionic liquid-based liquid electrolyte solution in pouch cell configuration, we report 800 cycles at 1.6 mA/cm2 and 25 °C without applying external pressure. This cell enables an initial discharge capacity of about 3 mAh/cm2 and a discharge capacity retention of about 85%.

A stable solid-state lithium–oxygen battery enabled by heterogeneous silicon-based interface

Solid-state lithium-metal batteries using inorganic solid-state electrolyte (SSE) instead of liquid-electrolyte, especially lithium–oxygen (Li-O2) battery, have attracted much more attention due to their high-energy density and safety. However, the poor interface contact between electrodes and SSEs makes these batteries lose most of their capacity and power during cycling. Here we report that by coating a heterogeneous silicon carbide on lithium metal anode and Li1.5Al0.5Ge1.5P3O12 (LAGP)-SSE, a good interface contact is created between the electrode and electrolyte that can effectively reduce the interface impedance and improve the cycle performance of the assembled battery. As a result, the solid-sate Li-O2 battery demonstrates a cycle lifespan of ∼78 cycles being at least 3-times higher than the solid-state Li-O2 battery without silicon carbide with a capacity limitation of 1000 mAh g−1 at 250 mA g−1. The characterization of discharge products indicates a typical two-electron convention of oxygen-to-lithium oxide for the solid-state Li-O2 battery system. This work paves a way for developing high-energy long-cycle solid-state lithium-metal battery. The work provides insights into the interface between the Li-metal and SSE to develop high-energy long-cycle all solid-state Li-metal batteries.

Observation of Li+ jumps in solid inorganic electrolytes over a broad dynamical range: A case study of the lithium phosphidosilicates Li8SiP4 and Li14SiP6

7Li NMR spectroscopy is known to be very sensitive to translational motion in solids and therefore highly suited for investigating temperature-dependent Li+ dynamics. A number of different NMR methods are available for choosing the dynamical range of the observed Li+ jump frequencies present in inorganic solid-state electrolytes. This includes 7Li spin-alignment echo NMR spectroscopy, static 7Li lineshape analysis, and 7Li spin-lattice relaxometry that can be used to detect Li+ jumps in the Hz, kHz, and MHz range, respectively. We introduce and discuss these NMR techniques with respect to their theoretical description and practical application to investigate the Li+ dynamics at different time scales for the two solid-state electrolytes Li8SiP4 and Li14SiP6. The data evaluation for all methods is discussed in detail, focusing on the determination of Li+ jump frequencies and activation energies for the investigated self-diffusion processes in a given structure.

An enhanced interface between garnet solid electrolyte and lithium through multifunctional lithium titanate anode-additive for solid-state lithium batteries

Garnet-structured solid-state electrolytes are getting considerable attention due to their high figure of merit over other inorganic solid-state electrolytes. The high lithium-ion conductivity and exceptional stability with metallic lithium over a wide voltage window open the door for the practical realization of an all-solid-state battery. However, the lithiophobic nature of garnet solid electrolytes creates huge interface resistance, which restricts achieving high critical current density. Herein a multifunctional composite anode containing lithium metal and lithium titanate (Li4Ti5O12) is introduced to tackle the interface challenges with the garnet solid electrolyte. The partial reduction of titanium in the composite enhances the electronic conductivity of the anode, and the intrinsic structural advantages of lithium titanate are expected to accommodate volume change as well. The prepared symmetric cell with the composite anode is found to have a minimal areal-specific resistance of 27 Ω cm2, while that of the pristine lithium anode is 249 Ω cm2. The cell has also run with a better critical current density (0.35 mA cm−2) than the pristine lithium (0.15 mA cm−2). A full cell study with a lithium iron phosphate cathode offers a capacity of 145 mAh g−1 at 0.2 C and runs for 100 cycles at 1 C with minimum capacity loss.

Recent progress and strategic perspectives of inorganic solid electrolytes: fundamentals, modifications, and applications in sodium metal batteries.

Solid-state electrolytes (SEs) have attracted overwhelming attention as a promising alternative to traditional organic liquid electrolytes (OLEs) for high-energy-density sodium-metal batteries (SMBs), owing to their intrinsic incombustibility, wider electrochemical stability window (ESW), and better thermal stability. Among various kinds of SEs, inorganic solid-state electrolytes (ISEs) stand out because of their high ionic conductivity, excellent oxidative stability, and good mechanical strength, rendering potential utilization in safe and dendrite-free SMBs at room temperature. However, the development of Na-ion ISEs still remains challenging, that a perfect solution has yet to be achieved. Herein, we provide a comprehensive and in-depth inspection of the state-of-the-art ISEs, aiming at revealing the underlying Na+ conduction mechanisms at different length scales, and interpreting their compatibility with the Na metal anode from multiple aspects. A thorough material screening will include nearly all ISEs developed to date, i.e., oxides, chalcogenides, halides, antiperovskites, and borohydrides, followed by an overview of the modification strategies for enhancing their ionic conductivity and interfacial compatibility with Na metal, including synthesis, doping and interfacial engineering. By discussing the remaining challenges in ISE research, we propose rational and strategic perspectives that can serve as guidelines for future development of desirable ISEs and practical implementation of high-performance SMBs.

Influence of LiBF4 sintering aid on the grain boundary and conductivity of LAGP electrolyte

NASICON-type Li[Formula: see text]Al[Formula: see text]Ge[Formula: see text]P3O[Formula: see text](LAGP) is one of the most promising inorganic solid-state electrolytes (SSEs). However, its practical applications have been hindered due to the high grain boundary resistance and poor sintering performance. In this work, we introduce a novel LiBF4 sintering aid into LAGP to promote the growth of grains, decrease grain boundary resistance, and supplement the loss of lithium. The experimental results show that the ionic conductivity of LAGP-0.5 wt% LiBF4 has the highest ionic conductivity (3.21 × 10[Formula: see text]S/cm), grain boundary impedance decreases from 162.2 [Formula: see text] to 35.2 [Formula: see text], the relative density increases from 93.6% to 96.5%, and no impurity phase is observed in LAGP–0.5 wt% LiBF4. At the same ionic conductivity, the sintering temperature of LAGP without LiBF4 and with a small amount of LiBF4 decreases from 800[Formula: see text]C to 700[Formula: see text]C. The Li/LAGP-LiBF4/LiFePO4 cell presents excellent cyclic stability (capacity retention of the discharge capacity is still 117.5 mAhg[Formula: see text] after 100 cycles) and a high initial discharge capacity of 164.2 mAhg[Formula: see text] at 0.2 C.

Research advance of lithium-rich cathode materials in all-solid-state lithium batteries

The development of all-solid-state lithium batteries with high energy density, long cycle life, low cost and high safety is one of the important directions for the developing next-generation lithium-ion batteries. Lithium-rich cathode materials have been widely used in liquid lithium batteries for their higher discharge specific capacity (> 250 mAh/g) and energy density (> 900 Wh/kg), high thermal stability and low raw material cost. With the rapid development of high-performance lithium-rich cathode materials and solid-state electrolytes in all-solid-state lithium batteries, the application of lithium-rich cathode materials in all-solid-state lithium batteries is expected to make a breakthrough toward the target of 500 Wh/kg energy density of lithium-ion batteries. In this review, first, we elaborate the failure mechanism of lithium-rich cathode materials in all-solid-state lithium batteries. The poor electronic conductivity, irreversible redox reaction of anionic oxygen and structute transformation during the electrochemical cycling of lithium-rich cathode materials result in the low initial coulomb efficiency, poor cycling stability and voltage decay. In addition, the high operating voltage of lithium-rich cathode materials (> 4.5 V <i>vs</i>. Li/Li<sup>+</sup>) triggers off not only the conventional interfacial chemical reactions between anode and electrolyte, but also the release of oxygen, aggravating the interfacial electrochemical reactions, which reduces the stability of the cathode/electrolyte interface. Therefore, the intrinsic characteristics of lithium-rich cathode materials and the severe interfacial reaction of lithium-rich cathode/electrolyte greatly limit the application of lithium-rich cathode materials in all-solid-state lithium batteries. Then, we review the research progress of lithium-rich cathode materials in various solid-state electrolyte systems in recent years. The higher room temperature ionic conductivity and wider voltage window of inorganic solid-state electrolytes provide opportunities for the application of lithium-rich cathode materials in all-solid-state lithium batteries. At present, the application of lithium-rich cathode materials in all-solid-state lithium batteries is explored on the basis of sulfide, halide and oxide solid-state electrolyte systems, and important progress has been made in the studies of composite cathode preparation methods, interfacial reaction mechanisms and activation mechanisms. Finally, we summarize the current research hotspot of lithium-rich cathode all-solid-state lithium batteries and propose several strategies for their future studies, such as the regulation of cathode material components, the construction of lithium ion and electron transport pathways within the composite cathode, and the interfacial modification of cathode materials that have been shown to have significant effects in solving the failure problem.

Thermal Enhancement of Product Conductivity Raises Capacity in Solid-State Li-O2 Batteries

Li-O2 batteries are mainly limited by the poor conductivity of their discharge products as well as parasitic reactions with carbon-containing electrodes and electrolytes. Here, Li-O2 cells utilizing inorganic solid-state electrolytes are investigated as a means to operate at elevated temperature, thereby increasing the conductivity of discharge products. Growth of dense, conductive LixOy products further removes the need for high-surface area support structures commonly made of carbon. Patterned Au electrodes, evaporated onto Li7La3Zr2O12 (LLZO) solid electrolyte, are used to create a triple-phase boundary for the nucleation of the discharge product, with growth outward into the cell headspace with gaseous O2. Through capacity measurements and imaging, discharge product growths are estimated to reach a critical dimension of approximately 10 μm, far exceeding what would be possible for a conformal film based on its room temperature electronic conductivity. Raman spectroscopy and electrochemical mass spectrometry are used to characterize the discharge chemistry and reveal a mixed lithium oxide character, with evidence of trace lithium hydroxides and initial carbonate contamination. These results showcase that thermal enhancement of Li-O2 batteries could be a viable strategy to increase capacity when paired with solid electrolytes.

Effect of current density on the solid electrolyte interphase formation at the lithium∣Li6PS5Cl interface

Understanding the chemical composition and morphological evolution of the solid electrolyte interphase (SEI) formed at the interface between the lithium metal electrode and an inorganic solid-state electrolyte is crucial for developing reliable all-solid-state lithium batteries. To better understand the interaction between these cell components, we carry out X-ray photoemission spectroscopy (XPS) measurements during lithium plating on the surface of a Li6PS5Cl solid-state electrolyte pellet using an electron beam. The analyses of the XPS data highlight the role of Li plating current density on the evolution of a uniform and ionically conductive (i.e., Li3P-rich) SEI capable of decreasing the electrode∣solid electrolyte interfacial resistance. The XPS findings are validated via electrochemical impedance spectrsocopy measurements of all-solid-state lithium-based cells.

X-ray absorption spectromicroscopy gives access to Li1+xAlxGe2−x(PO4)3 (LAGP) local degradation at the anode-electrolyte interface

Batteries with inorganic solid-state electrolytes (ISSE) are attracting notable interest for next-generation systems implementing Lithium (Li) metal anodes, in view of achieving higher energy densities combined with superior safety. Notwithstanding extensive research and development work, this technology is not yet ready for industrial implementation, one of the key challenges being the stability of ISSEs, chiefly at the anodic interface. This work attacks this issue for the specific case of the LAGP/Li (Lithium Aluminium Germanium Phosphate/Lithium) interface with a micro-spectroscopic approach centred on post mortem Scanning Transmission X-ray Microscopy (STXM) of intact LMO/LAGP/Li thin-film batteries, microfabricated in discharged state. Pristine and cycled cells were mapped to pinpoint morphochemical changes, induced by electrochemical ageing. The evidenced shape changes, corresponding to mechanical damaging of the solid/solid electrodic interfaces correlate with LAGP decomposition at the anode, leading to reduction of Ge, whereas the chemical state at the cathodic interface is preserved. Thanks to its submicron spacial resolution, the STXM at the Ge L-edge and O K-edge spectra allowed to assess the highly localized nature of the chemical transformation of LAGP and its correlation with the formation of Li outgrowth features. • Scanning X-ray Microscopy of local degradation at the Lithium-LAGP interface in a thin-film battery. • STXM maps revealed morphochemical changes induced by electrochemical ageing. • Germanium chemical state changes occur only at the anode-electrolyte interface.

Bilayer Halide Electrolytes for All-Inorganic Solid-State Lithium-Metal Batteries with Excellent Interfacial Compatibility.

Inorganic solid-state electrolytes (ISSEs) have been extensively researched as the critical component in all-solid-state lithium-metal batteries (ASSLMBs). Many ISSEs exhibit high ionic conductivities up to 10-3 S cm-1. However, most of them suffer from poor interfacial compatibility with electrodes, especially lithium-metal anodes, limiting their application in high-performance ASSLMBs. To achieve good interfacial compatibility with a high-voltage cathode and a lithium-metal anode simultaneously, we propose Li3InCl6/Li2OHCl bilayer halide ISSEs with complementary advantages. In addition to the improved interfacial compatibility, the Li3InCl6/Li2OHCl bilayer halide ISSEs exhibit good thermal stability up to 160 °C. The Li-symmetric cells with sandwich electrolytes Li2OHCl/Li3InCl6/Li2OHCl exhibit long cycling life of over 300 h and a high critical current density of over 0.6 mA cm-2 at 80 °C. Moreover, the all-inorganic solid-state lithium-metal batteries (AISSLMBs) LiFePO4-Li3InCl6/Li3InCl6/Li2OHCl/Li fabricated by a facile cold-press method exhibit good rate performance and long-term cycling stability that stably cycle for about 3000 h at 80 °C. This work presents a facile and cost-effective method to construct bilayer halide ISSEs, enabling the development of high-performance AISSLMBs with good interfacial compatibility and thermal stability.

Differentiating grain and grain boundary ionic conductivities of Li-ion antiperovskite electrolytes

Recently, antiperovskites such as Li2OHX (X ​= ​Cl, Br) have gained attention as possible solid-state electrolytes for use in all-solid-state batteries. Their low melting point allows for scalable manufacturing, making them more attractive than other inorganic solid-state electrolytes, and their high ion selectivity and good mechanical rigidity are superior to those of polymer electrolytes. However, there is significant variation of up to three orders of magnitude between reported ionic conductivities in different studies. One of the likely reasons is that studies have not separated Li-ion conduction contributions from the grain and the grain boundaries. Therefore, in this study, we present an electrochemical impedance analysis of Li-ion antiperovskites (Li2OHBr and Li2OHCl) prepared by different methods: cold press, hot press, and melt casting. We thereby separate the contributions from grain ionic conduction and grain boundary ionic conduction. While each method gives the same grain conductivity, the grain boundary conductivity depends on the preparation method. The largest improvement in grain boundary conductivity was found using the melt-casting method. These results provide an explanation for the reported variations in ionic conductivity.

Silver Doped Lithium Metal Thin Films for Solid-State Batteries

Potential use of lithium metal anode is a primary factor behind the high-energy density promise of solid-state batteries. However, large anodic loads lead to void formation and contact loss at the lithium/solid electrolyte interface which, in turn, lead to much higher effective local current densities during the subsequent lithium plating, causing dendrite formation and cell shorting.1, 2 This is due to the slow self-diffusion of Li atoms/vacancies, which is an inherent limitation of lithium metal.3 Modifying the bulk physiochemical properties of lithium metal via doping/alloying (<10 at% dopant) is an attractive approach, as such a small concentration of dopants can alter lithium metal’s bulk properties, without lowering its energy density. As an example, pore formation was effectively eliminated by alloying Li with 10 at% Mg, although chemical diffusion of Li within the alloy still restricted its rate performance.4 In this work, we report the effects of Ag as a dopant on the morphological stability and rate capability of Li-Ag alloy anodes during electrochemical cycling, as its concentration is varied in Li from 0-10 at.%. The alloy samples are prepared as 10 μm thick films, a practical form factor for solid-state batteries, via a combination of sputtering and thermal evaporation. Comparison of performance as a function of Ag content will be presented for both polymeric and inorganic solid-state electrolytes. Structural characterization of the alloy anodes via complementary techniques will also be presented. This research was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL). This abstract has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). References Kasemchainan, J.; Zekoll, S.; Spencer Jolly, D.; Ning, Z.; Hartley, G. O.; Marrow, J.; Bruce, P. G., Critical stripping current leads to dendrite formation on plating in lithium anode solid electrolyte cells. Nature Materials 2019, 18 (10), 1105-1111.Krauskopf, T.; Hartmann, H.; Zeier, W. G.; Janek, J., Toward a Fundamental Understanding of the Lithium Metal Anode in Solid-State Batteries—An Electrochemo-Mechanical Study on the Garnet-Type Solid Electrolyte Li6.25Al0.25La3Zr2O12. ACS Applied Materials & Interfaces 2019, 11 (15), 14463-14477.Jow, T. R.; Liang, C. C., Interface Between Solid Electrode and Solid Electrolyte—A Study of the Li / LiI ( Al2 O 3 ) Solid‐Electrolyte System. Journal of The Electrochemical Society 1983, 130 (4), 737-740.Krauskopf, T.; Mogwitz, B.; Rosenbach, C.; Zeier, W. G.; Janek, J., Diffusion Limitation of Lithium Metal and Li–Mg Alloy Anodes on LLZO Type Solid Electrolytes as a Function of Temperature and Pressure. Advanced Energy Materials 2019, 9 (44), 1902568.