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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Electrolyte-driven interphase stabilization in high-voltage sodium-ion full cells

Sodium-ion batteries with a high-voltage O3-type layered oxide cathode paired with a hard carbon anode can offer high energy density; however, significant interfacial instabilities driven by electrode/electrolyte reactions limit a broader industrial adoption. Localized high concentration electrolytes (LHCEs) are a rational choice as they promote salt decomposition over solvent, forming stable, inorganic-rich electrode-electrolyte interphases (EEIs). We present here a comparison of high-voltage (4.2 V) hard carbon | NaNi 1/3 Fe 1/3 Mn 1/3 O 2 pouch cells in LHCEs and in a standard carbonate-based electrolyte by (i) examining the influence of diluent choice on the electrochemical performance of LHCEs and (ii) investigating how the electrolyte chemistry affects the composition and structure of EEIs formed. Importantly, LHCEs demonstrate superior electrochemical performance, achieving 37% higher capacity after 200 cycles (119 vs. 87 mA h g -1 ) compared to the carbonate-based electrolyte. The enhanced stabilization provided by LHCEs at the interface with high-voltage sodium layered oxide cathode is revealed by gas evolution measurements obtained through online electrochemical mass spectrometry (OEMS). Time-of-flight secondary ion mass spectrometry paired with focused ion beam and advanced statistical analyses reveal that the superior performance of LHCE stems from a robust, thin cathode electrolyte interphase formed on the sodium layered oxide cathode and a homogeneous solid electrolyte interphase formation on the hard carbon anode. Furthermore, this study highlights the critical importance of electrolyte design in interphase stabilization, which plays a key role in advancing sodium-ion batteries toward commercial viability.

25 ENERGY STORAGE↗
DOE OSTI2021

Resolving Chemical and Spatial Heterogeneities at Complex Electrochemical Interfaces in Li-Ion Batteries

The high specific capacities of Ni-rich transition metal oxides have garnered immense interest for improving the energy density of Li-ion batteries (LIBs). Despite the potential of these materials, Ni-rich cathodes suffer from interfacial instabilities that lead to crystallographic rearrangement of the active material surface as well as the formation of a cathode electrolyte interphase (CEI) layer on the composite during electrochemical cycling. While changes in crystallographic structure can be detected with diffraction-based methods, probing the chemistry of the disordered, heterogeneous CEI layer is challenging. In this work, we use a combination of ex situ solid-state nuclear magnetic resonance (SSNMR) spectroscopy and X-ray photoemission electron microscopy (XPEEM) to provide chemical and spatial information, on the nanometer length scale, on the CEI deposited on LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) composite cathode films. XPEEM elemental maps offer insight into the lateral arrangement of the electrolyte decomposition products that comprise the CEI and paramagnetic interactions (assessed with electron paramagnetic resonance (EPR) and relaxation measurements) in 13 C SSNMR provide information on the radial arrangement of the CEI from the NMC811 particles outward. Using this approach, here we find that LiF, Li 2 CO 3 , and carboxy-containing structures are directly appended to NMC811 active particles, whereas soluble species detected during in situ 1 H and 19 F solution NMR experiments (e.g., alkyl carbonates, HF, and vinyl compounds) are randomly deposited on the composite surface. We show that the combined approach of ex situ SSNMR and XPEEM, in conjunction with in situ solution NMR, allows spatially-resolved, molecular-level characterization of paramagnetic surfaces and new insights into electrolyte oxidation mechanisms in porous electrode films.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Directing High-Efficiency Na Plating with Carbon–Aluminum Junction Interfaces for Anode-Free Na Metal Batteries

Anode-free sodium metal batteries are highly promising for future energy storage but suffer from much faster cycling degradation as they are sensitive to even trace levels of irreversible side reactions. This work focuses on the most practical Al foil current collectors and systematically examined the effect of nano-sized carbon coating on improving the Na plating and stripping stability. We identified that the carbon-Al junction interface generated by carbon coating enabled more uniform Na depositing with lower overpotentials, delivering higher than 99.8% Faradaic efficiencies for a wide range of cycling currents between 0.5 and 3.0 mA cm -2 . This performance is much better than the 96.4% efficiency observed on uncoated Al foils under the same conditions, and was also confirmed under lean electrolyte and freezing electrolyte conditions, and can be attributed to the stronger interfacial binding and enhanced sodiophilic properties of the carbon-aluminum junction sites. Furthermore, these sites not only ensure uniform Na plating but also eliminates side reactions that would otherwise cause electrolyte depletion. As a result, Na-metal free full cells assembled with high capacity Na 3 V 2 (PO 4 ) 3 cathode delivered ~ 85% capacity retention for 100 cycles, higher than the 73% of retention of uncoated Al foil.

25 ENERGY STORAGE↗
DOE OSTI2021

Structure–Capacitance Relationships of Graphene/Ionic Liquid Electrolyte Double Layers

The differential capacitance profile of electrochemical interfaces reflects the physical properties of the double layer. For carbon electrodes and ionic liquid based electrolytes, these capacitance profiles are not fully understood. In this work, we utilize constant voltage molecular dynamics simulations to compute differential capacitance profiles of ionic liquids [BMIm + ][BF 4 - ] and [BMIm + ][TFSI - ] mixed with acetonitrile and 1,2-dichloroethane, at model graphene electrodes. We find that both pure and 10% mole fraction ionic liquid electrolytes exhibit camel shaped capacitance profiles with two peaks on either side of a minimum centered at the potential of zero charge. This profile shape results from electric field induced rearrangement of ion structure within the inner layer closest to the electrode interface. At low potential, the ionic liquid inner layer is concentrated with non-polar tri-fluoromethyl and butyl functional groups of the anions and cations, corresponding to the minimum of the capacitance profiles. With increasing voltage, electrostatic interactions of polar/charged functional groups with the electrode surface compete with these non-polar interactions, leading to ion rearrangement that increases the inner layer charge density and results in higher capacitance. After the ion restructuring is complete, the response saturates and capacitance diminishes. The presence of organic solvent significantly changes the composition of the inner layer. For example, strong non-polar interactions between dichloroethane molecules and the graphene surface substantially block ion/electrode contact at moderate potentials. Overall, our simulations highlight the dynamic nature of the inner region of organic electrolyte double layers, and the sensitive dependence on electrolyte composition and applied voltage.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Redox Couples Control Band Bending, Photovoltage, and Quasi-Fermi Levels in Tungsten Oxide (WO 3 ) Photoanodes

Tungsten oxide (WO 3 ) is a well-known photoanode and photocatalyst for photoelectrochemical (PEC) water oxidation. Because the compound has a deep valence band, it can facilitate the oxygen evolution reaction without added cocatalysts, and it can drive the oxidation of species with much higher electrochemical potentials, including the conversion of water to hydrogen peroxide, sulfate to persulfate, and iodate to meta-periodate. Here, we use the liquid vibrating Kelvin probe surface photovoltage (liquid VK-SPV) technique in combination with open circuit potential (OCP) and photoelectrochemical (PEC) scans to assess the possibility of reaching such oxidizing potentials in aqueous electrolytes and at open circuit. Here, this is done by mapping the quasi-Fermi levels of electrons and holes at the interfaces as a function of the light intensity. Nanostructured WO 3 photoelectrodes for this purpose were fabricated by thermal annealing of a tungstic acid solution on fluorine-doped tin oxide. Electrochemical measurements are conducted at open circuit and 400 nm LED light illumination in electrolytes containing fast (O 2 /H 2 O 2 ), slow (O 2 /H 2 O), and very oxidizing (NaIO 4 /NaIO 3 ) redox couples. Photovoltage values scale with the light intensity and with the built-in potential for each redox couple and reach values up to 0.61 V under 20 mW cm –2 illumination for the NaIO 4 electrolyte. This shows that the photoelectrodes behave like Schottky-type diodes whose maximum possible energy output is determined mainly by the built-in voltage of each junction. For slow redox couples, the quasi-Fermi level of the holes increases with light intensity due to hole accumulation at the WO 3 –liquid interface. For example, for the O 2 /H 2 O electrolyte, interfacial hole accumulation and removal occur on the 90–300 s time scale. For the fast hole acceptor H 2 O 2 , on the other hand, the quasi-Fermi level of the photoholes is pinned to the electrochemical potential of the O 2 /H 2 O 2 couple. This limits the energy conversion efficiency of the electrode. Overall, these results reveal the influence of charge transfer thermodynamics and kinetics on the photovoltage of WO 3 . Furthermore, the work further establishes VK-SPV as a contactless method to observe the photovoltage, carrier dynamics, and quasi-Fermi levels of semiconductor-liquid junctions.

Electrodes↗
DOE OSTI2021

Orientation-Dependent Distortion of Lamellae in a Block Copolymer Electrolyte under DC Polarization

Lithium-salt-doped block copolymers have the potential to serve as solid electrolytes in rechargeable batteries with lithium metal anodes. In this work, we use small-angle X-ray scattering (SAXS) to study the structure of polystyrene-block-poly(ethylene oxide) (PS-b-PEO) doped with bis-(trifluoromethylsulfonyl)amine lithium salt (LiTFSI) during direct current (dc) polarization experiments in lithiu-lithium symmetric cells. The block copolymer studied is nearly symmetric in composition, has a total molecular weight of 39 kg mol -1 , and exhibits a lamellar morphology at all studied salt concentrations. When ionic current is passed through the electrolyte, a salt concentration gradient forms that induces a spatial gradient in the domain spacing, d. The dependence of d on distance from the positive electrode, x, was determined experimentally by scanning the incident X-ray beam from one lithium electrode to the other. By studying the two-dimensional (2D) SAXS patterns as a function of azimuthal scattering angle, we find that lamellae with PS/PEO interfaces oriented perpendicular to the flow of ionic current (LAM ⟂ ) swell and contract to a greater degree than those with interfaces oriented parallel to the current direction (LAM || ). While domains with the LAM ⟂ do not provide direct conducting pathways between the electrodes, our analysis suggests that they play an important role in establishing the salt concentration gradient necessary for sustaining a large ionic current through greater expansion and contraction.

25 ENERGY STORAGE↗
DOE OSTI2025

Role of Salt Concentration on Interphase Dynamics and Chemistry of Silicon Anodes during Electrochemical Cycling

We investigated the chemistry and structure of the solid electrolyte interphase (SEI) grown over a silicon anode as a function of the lithium salt concentration. In these experiments, in situ neutron reflectivity measurements were performed to measure the thickness and composition of the SEI formed from 1.0 and 5.5 M lithium bis(trifluoromethane)sulfonimide (LiTFSI) in standard ethylene carbonate:dimethyl carbonate electrolytes. These measurements reveal the formation of a 350+ Å thick SEI layer that is predominantly organic (∼80%) and dimensionally stable when using a 1.0 M salt solution. In contrast, increasing the salt concentration to 5.5 M resulted in an SEI that exhibited thickness changes from 100 to 375 Å and became up to 30% inorganic. In conclusion, these compositional and structural changes point to the role of salt speciation on the resulting passivation of silicon electrodes and indicate the need to form more organic-like passivation layers to promote the calendar life of silicon anodes.

Electrodes↗
DOE OSTI2022

Understanding the Effect of Cathode Composition on the Interface and Crosstalk in NMC/Si Full Cells

Crosstalk between the cathode and the anode in lithium-ion batteries has a great impact on performance, safety, and cycle lifetime. Still, no report exists for a systematic investigation on crosstalk behavior in silicon (Si)-based cells as a function of transition metal composition in cathodes. We studied the effect of crosstalk on degradation of Si-rich anodes in full cells with different cathodes having the same crystal structure but different transition metal compositions, such as LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NM111), LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532), and LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811). We found that the transition metal composition in cathodes, especially Mn ion concentration, significantly affects electrolyte decomposition reactions, even from very early cycles. This change causes differences in the solid electrolyte interphase (SEI) chemistry of each aged Si sample. As a result, each of the aged Si samples has a different electrochemistry, in terms of initial Coulombic efficiency and the mechanism of capacity fade.

25 ENERGY STORAGE↗
DOE OSTI2023

Enhanced Electrochemical Performance of Disordered Rocksalt Cathodes Enabled by a Graphite Conductive Additive

Cobalt-free cation-disordered rocksalt (DRX) cathodes are a promising class of materials for next-generation Li-ion batteries. Although they have high theoretical specific capacities (>300 mA h/g) and moderate operating voltages (~3.5 V vs Li/Li + ), DRX cathodes typically require a high carbon content (up to 30 wt %) to fully utilize the active material which has a detrimental impact on cell-level energy density. To assess pathways to reduce the electrode’s carbon content, the present study investigates how the carbon’s microstructure and loading (10–20 wt %) influence the performance of DRX cathodes with the nominal composition Li 1.2 Mn 0.5 Ti 0.3 O 1.9 F 0.1 . While electrodes prepared with conventional disordered carbon additives (C65 and ketjenblack) exhibit rapid capacity fade due to an unstable cathode/electrolyte interface, DRX cathodes containing 10 wt % graphite show superior cycling performance (e.g., reversible capacities ~260 mA h/g with 85% capacity retention after 50 cycles) and rate capability (~135 mA h/g at 1000 mA/g). Furthermore, a suite of characterization tools was employed to evaluate the performance differences among these composite electrodes. Overall, these results indicate that the superior performance of the graphite-based cathodes is largely attributed to the: (i) formation of a uniform graphitic coating on DRX particles which protects the surface from parasitic reactions at high states of charge and (ii) homogeneous dispersion of the active material and carbon throughout the composite cathode which provides a robust electronically conductive network that can withstand repeated charge–discharge cycles. Overall, this study provides key scientific insights on how the carbon microstructure and electrode processing influence the performance of DRX cathodes. Based on these results, exploration of alternative routes to apply graphitic coatings is recommended to further optimize the material performance.

25 ENERGY STORAGE↗
DOE OSTI2022

A Superior Carbonate Electrolyte for Stable Cycling Li Metal Batteries Using High Ni Cathode

Li metal batteries pairing Li metal anode with high-nickel layer structured oxide cathode are a promising energy storage technology to achieve high energy density. To obtain long cycling life for Li metal batteries, the electrolyte plays a pivotal role in stabilizing both the Li metal anode and the high-nickel cathode upon electrochemical cycling. Herein, we report a carbonate electrolyte that enables a Li||LiNi 0.8 Mn 0.1 Co 0.1 O 2 pouch cell to achieve a high gravimetric energy density of 366 Wh/kg and unprecedented cycling stability with 80% capacity retention after 335 cycles. Here, the 19 F quantitative nuclear magnetic resonance spectroscopy and interface characterization demonstrate that FEC and LiDFOB can reduce the consumption rate of each other and the electrolyte, form a robust LiF-rich SEI on Li metal anode, and improve the microstructure integrity of the high-nickel cathode.

25 ENERGY STORAGE↗
DOE OSTI2025

The Role of Catholyte Modulation in Suppressing the Initial Capacity Fade of Zinc Electrolytic Manganese Dioxide Coin Cells

Despite its potential for zinc–manganese oxide batteries, electrolytic manganese dioxide (EMD) can experience capacity fade due to a deficiency in the Mn 2+ supply at the cathode electrolyte interphase (CEI) from side reactions, even in the presence of an electrolyte additive. In this work, electrolyte loading modulation at the cathode electrolyte interface (CEI) was correlated with Zn∥EMD cell capacity retention and cycling performance, as a proposed measure to curb the initial capacity fade observed in EMD. Initial galvanostatic charge/discharge cycling, with varied electrolyte loading, revealed severe capacity fade (from ~188 to 10 mAh g –1 for the highest loading of 200 μL) within the first 15 cycles. Such a decrease in cell capacity is correlated with the formation of a Mn 4+ deposit on the current collector and consequently, the Mn 2+ depletion at CEI, as was supported by elemental and Raman analyses. Interestingly, confinement of the electrolyte to the CEI at a lower (≤15 μL) electrolyte loading mitigated Mn 4+ side-deposition, maintaining the cell capacity at >80% over the first 15 cycles. Interfacial Mn supply/depletion could be monitored via voltammetric analysis based on changes of the Zn 2+ insertionreduction peak. Additional galvanostatic experiments corroborated the voltammetric interpretation and the proposed degradation pathway in the studied cell conditions. The outcomes of this work provide practical insight into coin-cell design and configuration strategies for developing Zn∥EMD batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Synergistic Effects of the Electric Field Induced by Imidazolium Rotation and Hydrogen Bonding in Electrocatalysis of CO 2

The roles of the ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF₄]), and water in controlling the mechanism, energetics, and electrocatalytic activity of CO₂ reduction to CO on silver in non-aqueous electrolytes were investigated. The first electron transfer occurs to CO₂ at reduced overpotentials when it is trapped between the planes of [EMIM]⁺ ring and electrode surface due to cation re-orientation as determined from voltammetry, in-situ surface-enhanced Raman spectroscopy, and density functional theory calculations. Within this interface, water up to 0.5 M does not induce significant faradaic activity, opposing the notion of it as a free proton source. Instead, water acts as a hydrogen bond donor and the proton is sourced from [EMIM]⁺. Furthermore, this study demonstrates that alcohols with varying acidity tune the hydrogen bonding network in the interfacial microenvironment to lower the energetics required for CO₂ reduction. Here, the hydrogen bonding suppresses the formation of inactive carboxylate species, thus preserving the catalytic activity of [EMIM]⁺. The ability to tune the hydrogen bonding network opens new avenues for advancing IL-mediated electrocatalytic reactions in non-aqueous electrolytes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Locally Confined Polysulfide-Reactive Electrolytes for Shuttle-Free Sodium–Sulfur Batteries

Sodium-sulfur batteries promise high-energy-density and sustainable electrochemical energy storage but suffer from uncontrolled polysulfides dissolution and high sodium reactivity. These challenges fundamentally originate from poor electrolyte-electrode compatibility. Current electrolyte research inadequately addresses the trade-off between minimal polysulfides solvation and stabilizing sodium interfaces. Here, we present a locally-confined polysulfide-reactive electrolyte strategy that mediates the polysulfide dissolution dynamics and sodium stability by leveraging an electrophilic solvating species with a localized high-concentration electrolyte. This design enables shuttle-free cell operation by synergistically restricting the global solvating power of the electrolyte through intermolecular interactions and locally scavenging sparingly dissolved polysulfides via electrolyte electrophilicity. The precisely confined surface reaction facilitates a protective cathode-electrolyte interface, realizing a quasi-solid-state sulfur conversion in our liquid ether-based electrolyte, which crucially avoids crossover-induced catastrophic sodium-metal degradation. The proposed electrolyte demonstrates long-term cycling of high-mass-loading sulfur cathodes (> 3 mg S cm −2 with commercial carbon host and 70 wt% sulfur content), which afford 710 mA h g −1 over 400 cycles in coin cells and steady pouch cell operation over 180 cycles. Furthermore, this work establishes a scalable electrolyte design protocol that regulates the reaction chemistry of highly reactive electrodes, offering a pathway toward sustainable renewable energy storage.

25 ENERGY STORAGE↗
DOE OSTI2025

Interfacial Cation Arrangement Controls Electrocatalytic Kinetics in CO 2 Reduction

The identity of electrolyte cations is known to strongly influence electrocatalytic activity, but the relationship between their interfacial arrangement and observed performance remains poorly understood. Organic cations, with their molecular tunability, provide a powerful platform for systematically probing these effects. Here, we leverage phosphonium-based geminal dications to control interfacial cation arrangement and identify the variables that most strongly influence catalytic rates. As a case study, we examine CO 2 reduction to CO over polycrystalline silver electrodes in dry aprotic acetonitrile. Through a combination of rotating disk electrode measurements, electrochemical impedance spectroscopy, and molecular dynamics simulations, we decouple the effects of cation–electrode distance and interfacial cation density on catalytic rates. We find that smaller, more densely packed cations induce stronger interfacial electric fields, which lower the activation barrier for CO 2 adsorption and increase reaction rates. Using geminal phosphonium dications [C n (P mmm ) 2 ][ClO 4 ] 2 , we demonstrate that both the vertical and lateral positioning of organic cations within the electrical double layer independently affect reactivity. These results demonstrate that electrolyte cation identity primarily influences catalytic kinetics by determining how efficiently charge can be arranged at electrochemical interfaces. Altogether, our findings support an electrostatic view of cation effects in catalysis and provide design principles for next-generation electrolytes.

Cations↗
DOE OSTI2024

Tuning the solvation structure with salts for stable sodium-metal batteries

Sodium-metal batteries are an appealing, sustainable, low-cost alternative to lithium metal batteries due to the high abundance and theoretical specific capacity (1,165 mA h g -1 ) of sodium. However, the poor compatibility of the electrolyte with the cathode and anode leads to unstable electrode-electrolyte interphases. Here we introduce the concept of using a salt as a diluent, which enables the use of a single non-flammable solvent, such as trimethyl phosphate. By using sodium nitrate (NaNO 3 ) salt as a model diluent, we report a 1.1 M NaFSI-NaNO 3 -trimethyl phosphate electrolyte that forms a stable interface with sodium-metal anode. In addition, the formation of robust cathode-electrolyte interphases on Na(Ni 0.3 Fe 0.4 Mn 0.3 )O 2 cathode facilitates smooth phase transitions, thus leading to stable cycle life with a capacity retention of 80% over 500 cycles at C/5 rate in Na||Na(Ni 0.3 Fe 0.4 Mn 0.3 )O 2 cells. Further, the work demonstrates a promising approach towards the development of safe, low-cost, sustainable high-performance sodium-metal batteries. Electrolytes with non-flammable solvents are important for the safe operation of sodium-metal batteries. Here the authors report an electrolyte engineering approach, employing salts as a diluent, to enhance interfacial stability and overall safety.

25 ENERGY STORAGE↗
DOE OSTI2022

Investigation of the Electrode-Electrolyte Interphase in Ester-Based Electrolytes in NCM523/Graphite Cells

The use of methyl acetate (MA) and methyl propionate (MP) as co-solvents in carbonate/LiPF 6 electrolytes have been investigated in LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523)/graphite cells to improve electrochemical performance at low temperature (−20 °C). Consistent with previous investigations, improved low temperature performance was observed with all electrolyte formulations containing esters. Detailed ex situ surface analysis of the surface films generated with the ester-based electrolytes containing electrolyte additives reveal significant changes to the SEI on graphite upon cycling at moderately elevated temperature (45 °C). In the presence of vinylene carbonate (VC) lithium plating is observed upon cycling at low temperature (−20 °C) which leads to a thicker solid electrolyte interface (SEI) upon cycling at 45 °C. Incorporation of fluoroethylene carbonate (FEC) as an electrolyte additive results in the generation of a thin SEI and alters the structure of the surface film on the NCM523 cathode resulting in stable cycling over a wide temperature range.

Rodrigo, Nuwanthi D. (ORCID:0000000343129536)↗
DOE OSTI2023

Development, Characterization, and Testing of Solid-State Electrolytes for Batteries

Traditional liquid electrolytes used in lithium (Li) metal batteries (LMBs) have severe safety issues, poor power density, as well as thermal and electrochemical instability that prevents their scaling to newer applications, such as electric vehicles. Using sulfide-based solid-state electrolytes (SSEs) is a viable method to address many of the issues that plague LMBs. However, the key issue preventing the expansion of sulfide-based SSEs is an interplay between poor interfacial stability with the electrodes and massive external stack pressure required to maintain electrode-electrolyte contact. The need for extensive pressure requires large system-level (i.e., battery pack used in an electric vehicle) housing that causes a disconnect between performance at a smaller scale and actual application. Secondary prevention to sulfide-based SSE adoption are difficulties in manufacturing, as toxic deterioration occurs when these materials are exposed to humidity, as well as drastic reduction in SSE performance at low temperature. This work hypothesizes that unique interfacial designs of electrodes and the modification of the sulfide-based SSE will enable reduction of necessary external cell pressure, and therefore support the design of practical LMBs. This will be done through collaboration within Idaho National Laboratory (INL), where manufacturing practices will be parameterized to produce low defect, low porosity SSEs with slight modifications. Next, artificial interfaces will be produced on electrodes to observe the conformality and mass transport properties between the modified SSE and pre-treated anode. External pressure on Li-metal cells will also be parameterized to reduce interfacial impedance while a reduction in the pressure will allot reasonable housing design for larger scale applications. Focus on novelty in this work occurs by modifications to the solid-solid interfaces between electrolyte and electrode, done through doping of the electrolyte and production of artificial interfaces on the Li-metal anode. The modifications at these interfaces, in addition to modified external pressure could identify and address the poor interfacial impedance that hinders high performance SSEs. Fundamental understanding on how to reduce the key hindrances of all-solid-state batteries (ASSBs) will support the advancement for larger scale production and performance, of which will be held in perspective for future works. Beyond battery development, the knowledge gained from process control and defect analysis is applicable to other ceramic systems, such as nuclear fuel coatings and high temperature electrolyzers.

25 ENERGY STORAGE↗