Thin Anode Research Articles

Active fluorobenzene diluent regulated tetraglyme electrolyte enabling high-performance Li metal batteries

Electrolytes with superior compatibility with Li metal anodes and high-voltage cathodes are crucial for high-voltage Li metal batteries. Herein, tetraglyme (G4) with both high oxidation stability and reduction stability is employed to design localized high concentration electrolyte (G4-FB) regulated by active diluent fluorobenzene (FB) via active diluent-anion synergy strategy. FB possesses high activity for generating LiF and cooperates with anions to construct robust LiF-rich solid electrolyte interphases (SEIs) and cathode-electrolyte interphases (CEIs), effectively enhancing the interfacial stability of Li metal anodes and LiNi0.8Mn0.1Co0.1O2 (NCM811) cathodes. G4-FB enables high-efficiency (99.7%), long-term (1439 h) and dendrite-free cycle of Li||Li cells and Li||Cu cells. Parasitic interface reactions and structural damages of NCM811 are significantly suppressed by the robust LiF-rich CEIs. G4-FB markedly boosts the performance of NCM811||Li cells even under harsh conditions, including high voltage (4.5 V), high temperature (60°C), high cathode loading (3.6 mAh cm−2) and thin Li metal anode (50 μm), which display a high capacity retention of 86.3% after 300 cycles. The powerful diluent effect of FB remarkably decreases viscosity, increases ionic conductivity and enhances wettability of G4-FB. This work presents a promising design strategy of highly efficient electrolytes for Li metal batteries.

A Universal Design of Lithium Anode via Dynamic Stability Strategy for Practical All-solid-state Batteries.

All-solid-state Li-metal battery (ASSLB) chemistry with thin solid-state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li-metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra-thin LMA (20 μm) is in-situ constructed with uniform highly Li-ion conductive solid-electrolyte interphase and composite-polymer interphase (CPI) via electroplating process. As a result, the passivation layer with poor Li-ion conduction on Li anode can be dissolved and small surface resistance can be achieved due to the good compatibility of CPI to SSEs. The cycling of Li symmetric cell with Li6PS5Cl thin film electrolyte (< 100 μm) shows a high critical current density of > 2.0 mA cm-2 with excellent cycling stability at 1.0 mA cm-2. The ASSLBs paring with Ni-rich LiNi0.6Mn0.2Co0.2O2 cathode demonstrated the feasibility of engineered LMA design by presenting good rate capability from 0.1C to 1.0 C at room temperature, as well as long-term cycling stability (81% retention after 100 cycles). This work represents a general pathway to make thin dendrite-free LMA available for high-energy-density ASSLBs.

Commercial Cellulosic Paper-Based Solid Electrolyte for High-Temperature Lithium-Sulfur Batteries.

Solid-state lithium-sulfur (Li-S) batteries show promise for future electric mobility due to their high energy density potential. However, high internal impedance, Li polysulfide shuttling, and dendrite formation exist. Herein, we present a Li-rich cellulosic solid-state electrolyte (SSE) that, when paired with a sulfurized polyacrylonitrile (SPAN) cathode, leads to durable Li-S batteries for use in the room temperature to 50 °C range. Our cellulosic SSE is prepared via a scalable, viable method and exhibits high area-normalized conductance (24.4 mS cm-2) and Li-ion transference number (0.76) at 50 °C. After 150 cycles at 50 °C, solid-state Li-S half cells retained 82.2% capacity. Full cells with a thin Li foil anode and an N/P ratio of 4.92 showed stable cycling at both room temperature and 50 °C for nearly 40 cycles, attributed to the excellent conformability of the paper-derived SSE. These results place our work among the top few for SPAN-based all-solid-state Li-S batteries.

Techno-economic assessment of thin lithium metal anodes for solid-state batteries

AbstractSolid-state lithium metal batteries show substantial promise for overcoming theoretical limitations of Li-ion batteries to enable gravimetric and volumetric energy densities upwards of 500 Wh kg−1 and 1,000 Wh l−1, respectively. While zero-lithium-excess configurations are particularly attractive, inhomogeneous lithium plating on charge results in active lithium loss and a subsequent coulombic efficiency penalty. Excess lithium is therefore currently needed; however, this negatively impacts energy density and thus limiting its thickness is essential. Here we discuss the viability of various technologies for realizing thin lithium films that can be scaled up to the volumes required for gigafactory production. We identify thermal evaporation as a potentially cost-effective route to address these challenges and provide a techno-economic assessment of the projected costs associated with the fabrication of thin, dense lithium metal foils using this process. Finally, we estimate solid-state pack costs made using thermally evaporated lithium foils.

Solvation Structure Engineering via Inorganic–Organic Composite Layer for Corrosion‐Resistant Lithium Metal Anodes in High‐Concentration Electrolyte

AbstractHigh‐concentration electrolytes have been reported to form an anion‐derived, inorganic‐rich solid electrolyte interphase on lithium metal electrodes; however, these electrodes suffer from high Li corrosion by the coordinated anions and consequent anion depletion. Herein, the study reports a composite layer comprising single‐ion conducting ceramic (SICC) nanoparticles and a gel polymer electrolyte (GPE), which can suppress the Li corrosion in a high‐concentration electrolyte based on lithium bis(fluorosulfonyl)imide (LiFSI) and a weakly solvating solvent (N,N‐dimethylsulfamoyl fluoride, FSA). The lithium‐ion space charges formed at the SICC/GPE interface reduce the coordination of anions in the composite layer, suppressing their decomposition. A Li | LiNi0.8Co0.1Mn0.1O2 (NCM811) pouch bi‐cell with a composite layer‐coated thin lithium metal anode (N/P = 1, thickness: 20 µm) delivers projected gravimetric (316 Wh kg−1) and projected volumetric (1433 Wh L−1) energy densities and exhibits stable operation for 350 cycles, with 70% capacity retention at 1/3 C charge–discharge rate. The engineering of the solvation structure through the inorganic–organic composite layer represents a practical strategy for developing corrosion‐resistant lithium metal anodes in high‐concentration electrolytes.

Chiral electrolytes for rechargeable metal batteries

Charge transfer at the liquid (electrolyte)-solid (metal) interfaces is of fundamental importance to metal electrochemical deposition that further determines the reversibility and kinetics of energy-dense rechargeable metal batteries (RMBs). We demonstrate the fast charge transfer at the electrolyte-metal interfaces for lithium metal by designing and synthesizing electrolytes with chiral solvents: R (or S)-1,2-dimethoxypropane (R-DMP or S-DMP) and R (or S)-4-methyl-1,3-dioxolane (R-MDOL or S-MDOL). The chiral-induced spin selectivity is considered to produce spin-polarized metal surfaces, enabling the improvement in charge transfer rate and efficiency. The deposited Li metal in chiral electrolytes shows smooth and uniform morphologies, as well as high initial (>95%) and average (∼99.2%) Coulombic efficiency for Li metal stripping/plating process, thus prolonging the life-span of batteries using thin lithium anode (50 μm) to 400 cycles till 80% capacity retention. This work provides a distinct approach to regulate metal deposition beyond the limitation of ion de-solvation.

Realization of a Long-Lifespan Thin Li Metal Batteries Capable of Self-Recovery with a Functional Separator

Due to the rapid expansion of the electric vehicles (EVs) market, the demand for large-scale batteries is increasing. Particularly, EVs face several limitations in terms of battery volume and weight. Therefore, achieving high energy density in limited spaces requires a significant reduction in the volume of the anode. Recently, the research is underway on batteries that employ thin Li metal anodes, typically around 20-25μm thick, as the next generation of lithium-ion batteries. However, thin Li anodes present various challenges regarding their cycle life. Compared to Li metal, thin Li metal faces scarcity in lithium sources. Furthermore, due to the unstable formation and destruction of the Solid Electrolyte Interphase (SEI) during the plating-stripping process in Li metal anode charging and discharging, lithium ions and electrolyte are constantly consumed. These side reactions lead to decreased capacity and deteriorated lifespan characteristics. To maintain stable charging and discharging properties, it is necessary to minimize electrolyte decomposition by forming a stable SEI in the early cycle and continuously supplying consumed Li ions throughout the cycling process. Commonly used methods to supplement the limited lithium source of the thin Li anode and replenish consumed Li ions during charging and discharging represent the employing the high-concentration electrolytes (HCE). However, HCE have limits on the dissolved concentration of salts in the electrolyte, and the method of dissolving salts in the entire electrolyte is not attractive a cost perspective. Additionally, as the electrolyte concentration increases, viscosity also increases, leading to a decrease in ion mobility.In this study, high-concentration lithium bis(fluoromethanesulfonyl)imide (LiFSI) salts are coated onto commercial separators to provide a locally high-concentration environment at the electrode/electrolyte interface. This coating layer dissolves as Li ions are consumed, replenishing the depleted Li ions. Furthermore, the presence of high-concentration Li ions in the electrolyte eliminates free solvent. Reducing free solvent suppresses electrolyte consumption further. Additionally, by adopting LiFSI as the salt, rapid decomposition of anions in the initial cycle facilitates the formation of a stable LiF layer. The densely formed LiF layer exhibits high mechanical strength and electrochemical stability, aiding in achieving long-term characteristics.Li||Li symmetric cells were tested using commercial electrolytes, including 1M LiFSI in diethylene glycol dimethyl ether (DME) and 1M lithium hexafluorophosphate (LiPF6) in ethylene carbonate/ diethylene carbonate (EC/DEC). Both electrolytes showed improved cycle stability and lower polarization in cells using an ionically conductive salt-coated separator (SDL) compared to polyethylene (PE) separators. Particularly, the nucleation polarization observed during the initial charging process, when Li ions are deposited onto bare lithium metal, significantly decreased in SDL cells, indicating better Li ion affinity on the lithium surface of SDL cells. Tafel plots were used to analyze the exchange current at the electrode/electrolyte interface. The exchange current for PE was 1.09 mA/cm2, while for SDL, it was 1.52 mA/cm2, suggesting faster interfacial kinetics in SDL compared to PE. The results were also evident in rate capability tests, with the largest capacity difference observed at 5C. Scanning electron microscope (SEM) images revealed distinctly different Li ion deposits on the Cu foil. PE showed vigorous dendrite growth with many voids, while SDL exhibited dense Li deposition, attributed to the presence of high-concentration salts at the interphase, suppressing dendrite growth and inducing uniform Li ion flux. The stable interfacial characteristics were analyzed using X-ray photoelectron spectroscopy (XPS). After 100 cycles, PE showed a high proportion of electrolyte decomposition components, while SDL exhibited a higher proportion of LiF formation. These results demonstrate coated separator with LiFSI effectively suppressed electrolyte decomposition. Additionally, boehmite was pre-coated on the PE separator to endow with coating adhesion, resulting in improved surface morphology. When various commercial electrolytes were applied after salt coating, significantly enhanced wettability was observed compared to PE. Ultimately, half-cells were constructed using thin-film Li metal for galvanostatic charge-discharge tests, achieving superior cycle stability of over 200 cycles with SDL. Figure 1

Mechanistic Insights into the Electrochemical Oxidation of 5-Hydroxymethylfurfural on a Thin Film Ni Anode

Oxygen evolution reaction (OER) in ambient electrolyzers consumes a significant amount of energy and yields oxygen, an inherently low-value product. Therefore, it is imperative to choose anodic reactions that can make efficient use of the supplied energy to the electrolyzer when paired with a desired cathodic reaction such as CO2 reduction into value-added commodities. Utilizing biomass oxidation offers a promising avenue to reduce the overall energy input by >50% while producing high-value chemicals, and address the critical requirements for biomass conversion, a crucial 21st-century non-fossil carbon resource. In this work, we demonstrate the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) as an alternative to OER. This reaction not only reduces the theoretical overall energy input into the electrolyzer but also generates FDCA, a significant building block for the sustainable polyester PEF, which has a global market size of more than 30 Mt/yr. We present an experimental and computational approach to understand HMF oxidation on Ni-based catalysts. Our experimental investigation involves evaluating the effect of microenvironment on thin-film (5nm) Ni-catalyst in a pH range of 11-13 to understand the intrinsic kinetics of HMF oxidation. In addition, we compare the reaction energetics of OER and the hydride transfer reaction of the HMF oxidation using density functional theory to understand the competing reaction pathways on the anode. Using the experimental data, we also develop a Multiphysics model to evaluate the electrode kinetics and species concentration distribution near the catalyst surface to understand the implications of mass transport limitations in this electrochemical system. This comprehensive analysis could potentially provide new guidelines to design more energy-efficient anodes for upgrading sustainable alcohols.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Robust Fuel Cell Electrodes: Pt Thin Film Catalysts for Anode Reversal Tolerance

In recent years, polymer electrolyte membrane fuel cells (PEMFCs) have garnered significant attention due to their remarkable attributes including high power density, energy efficiency, and zero-emission characteristics. This surge in interest has primarily been driven by the potential of PEMFC-powered fuel cell electric vehicles (FCEVs) to substantially reduce carbon dioxide emissions in the transportation sector, thereby propelling the advancement of the hydrogen economy on a global scale. However, the widespread commercialization of FCEVs hinges upon addressing key challenges surrounding the durability and resilience of fuel cell systems.One critical issue that has emerged is the phenomenon of hydrogen starvation in the anode, particularly during start-up/shutdown or cold start scenarios, which can lead to rapid and severe degradation of PEMFC performance and durability through cell reversal. This degradation manifests quickly, often within minutes, resulting in abrupt cell failure. Extensive prior research has been devoted to unraveling the mechanisms underlying degradation induced by hydrogen starvation and cell reversal in PEMFCs, with the goal of identifying effective mitigation strategies to minimize damage to membrane electrode assembly (MEA) components.In this study, we introduce an innovative materials approach aimed at mitigating cell damage by employing a thin film Pt anode catalyst supported on Nafion nanowires in a co-axial configuration, referred to as coaxial nanowire electrode (CANE). Leveraging the high roughness of Nafion nanowires, CANE eliminates the need for conventional carbon support and exhibits exceptional tolerance to reversal-induced stress. We present a comprehensive evaluation of CANE as a reversal-tolerant anode, comparing its performance to that of conventional supported catalysts (Pt/C). Furthermore, we explore the potential for further enhancing durability by integrating iridium with the CANE anode. Finally, we will delve into our efforts to evaluate the feasibility of implementing this concept in structures that can be manufactured at scale. This research contributes to the ongoing efforts to enhance the robustness and longevity of PEMFC systems, thereby advancing the prospects of FCEVs as a sustainable and viable solution for future transportation needs.AcknowledgementThis research was supported by the Hydrogen and Fuel Cell Technologies Office (HFTO), Office of Energy Efficiency and Renewable Energy, US Department of Energy (DOE) through the Million Mile Fuel Cell Truck (M2FCT) consortia, technology managers G. Kleen and D. Papageorgopoulos. Authors would also like to acknowledge support for this work from the Laboratory Directed Research and Development (LDRD) program at Los Alamos National Laboratory (LANL) (2020200DR).

A MXene Modulator Enabled High‐Loading Iodine Composite Cathode for Stable and High‐Energy‐Density Zn‐I2 Battery

AbstractAchieving both high iodine loading cathode and high Zn anode depth of discharge (DOD) is pivotal to unlocking the full potential of energy‐dense Zn‐I2 batteries. However, this combination exacerbates the detrimental shuttle effect of polyiodide intermediates, significantly impairing the battery's reversibility and stability. Herein, this study reports an advanced high‐loading iodine cathode (denoted as MX‐AB@I) enabled by a multifunctional Ti3C2Tx MXene modulator, which presents high stability and energy density in Zn‐I2 batteries. Through comprehensive experimental and theoretical analyses, the intrinsic regulating mechanisms are elucidated by which the MXene modulator effectively suppresses polyiodide shuttling, enhances iodine conversion kinetics, and dramatically improves Zn anode reversibility. With the aid of the MXene modulator, the MX‐AB@I composite cathode achieves a high iodine mass loading of 23 mg cm−2 and realizes a practically high areal capacity of 4.0 mAh cm−2. When paired with a thin Zn anode (10 µm), this configuration realizes a high Zn DOD of 78.7% and a high energy density of 171.3 Wh kg−1, surpassing the majority of Zn‐I2 battery systems reported in the literature. This study presents an effective approach to designing high‐loading iodine cathodes for Zn‐I2 batteries by leveraging MXene modulators to regulate critical electrochemical reaction processes.

Functional Separator with Poly(Acrylic Acid)-Enabled Li2CO3-Free Garnet Coating for Long-Cycling Lithium Metal Batteries.

Lithium metal batteries (LMBs) possess a theoretical energy density far surpassing that of commercial lithium-ion batteries (LIBs), positioning them as one of the most promising next-generation energy storage systems. Modifying separators with composite coatings comprising oxide solid-state electrolyte (SSE) particles and polymers can improve the cycling stability and safety of LMBs. However, exposure to air forms Li2CO3 on oxide SSE particles, diminishing their ion flux regulation at the electrode/electrolyte interface. Utilizing the reaction of Li2CO3 with polyacrylic acid (PAA) to form lithium polyacrylate (LiPAA), an ultra-thin composite coating on polyethylene (PE) separator with Li2CO3-free Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles and LiPAA binder is fabricated in one step. The exposed Li2CO3-free LLZTO surface increases the ionic conductivity and lithium ion (Li+) transference number of the functional separator, resulting in small resistance and uniform Li deposition of the Li metal anode. Consequently, the Li//LiCoO2 cell with the functional separator exhibits a significantly improved life of 980 cycles with 80.9% capacity retention under lean-electrolyte conditions. Both the Li//LiCoO2 coin cell and pouch cell using thin Li foil anode demonstrate good cycling stability and high mechanical robustness. This study provides a green and scalable approach for fabricating advanced separators for LMBs.

A Quasi-Solid-State Polymer Lithium-Metal Battery with Minimal Excess Lithium, Ultrathin Separator, and High-Mass Loading NMC811 Cathode.

Solid-state batteries with lithium metal anodes are considered the next major technology leap with respect to today's lithium-ion batteries, as they promise a significant increase in energy density. Expectations for solid-state batteries from the automotive and aviation sectors are high, but their implementation in industrial production remains challenging. Here, we report a solid-state lithium-metal battery enabled by a polymer electrolyte consisting of a poly(DMADAFSI) cationic polymer and LiFSI in Pyr13FSI as plasticizer. The polymer electrolyte is infiltrated and solidified in the pores of a commercial LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode with up to 2.8 mAh cm-2 nominal areal capacity and in the pores of a 25 μm thin commercial polypropylene separator. Cathode and separator are finally laminated into a cell in combination with a commercial 20 μm thin lithium metal anode. Our demonstration of a solid-state polymer battery cycling at full nominal capacity employing exclusively commercially available components available at industrial scale represents a critical step forward toward the commercialization of a competitive all-solid-state battery technology.

ZnO Nanowire Cold Cathode Hemispherical X‐Ray Sources

AbstractCurved or spherical X‐ray sources are significant for use in intraoperative radiotherapy, adaptive static medical imaging, and high‐throughput industrial inspection, but they are hard to achieve using traditional thermionic cathode point electron sources. In this study, copper (Cu)‐doped zinc oxide (ZnO) nanowires grown on a brass substrate with a designed shape are proposed to achieve cold cathode hemispherical X‐ray sources. The strain‐driven solid–liquid growth model of Cu‐doped ZnO nanowires is proposed, and the oxidation temperature‐dependent and time‐dependent growth characteristics are investigated to optimize the morphologies of ZnO nanowire cold cathodes with a typical turn‐on field of 7.36 MV m−1, a maximum current of 12.54 mA (4.93 mA cm−2) and a uniform field emission image with an area of 2.54 cm2. Hemispherical X‐ray sources formed by Cu‐doped ZnO nanowire field emitters grown on spherical brass alloy and an Al thin film transmission anode target deposited on a hemispherical quartz glass are successfully fabricated, achieving an operating voltage of 39 kV, a dose rate of 240 µGyair s−1 and a projection X‐ray imaging resolution of 2.8 lp mm−1, demonstrating their promising use in a variety of applications.

Scalable Production of Thin and Durable Practical Li Metal Anode for High-Energy-Density Batteries.

Utilization of thin Li metal is the ultimate pathway to achieving practical high-energy-density Li metal batteries (LMBs), but its practical implementation has been significantly impeded by formidable challenges of poor thinning processability, severe interphase instability and notorious dendritic Li growth. Here we report a practical thin (10-40 μm) Li/Mo/Li2Se with concurrently modulated interphase and mechanical properties, achieved via a scalable mechanical rolling process. The in situ generated Li2Se and Mo not only enhance the mechanical strength enabling the scalable fabrication of thin Li metal, but also promote homogeneous Li electrodeposition. Significantly, the Li/Mo/Li2Se demonstrates ultrahigh-rate performance (15 mA cm-2) and ultralong-lifespan cycling sustainability (2700 cycles) with exceptional anti-pulverization capability. The Li|LiFePO4 cells show substantially prolonged cyclability over 1200 cycles with an ultralow decay rate of ~0.01 % per cycle. Moreover, the Li|LiNi0.8Co0.1Mn0.1O2 pouch cells deliver enhanced cycling stability even under the extremely harsh conditions of low negative-to-positive-capacity (N/P) ratio of ~1.2 and lean electrolyte of ~0.95 g Ah-1, showing an exceptional energy density of 329.2 Wh kg-1. This work sheds light on facile pathway for scalable production of durable thin Li metal anode toward reliable practicability.

Scalable Production of Thin and Durable Practical Li Metal Anode for High‐Energy‐Density Batteries

AbstractUtilization of thin Li metal is the ultimate pathway to achieving practical high‐energy‐density Li metal batteries (LMBs), but its practical implementation has been significantly impeded by formidable challenges of poor thinning processability, severe interphase instability and notorious dendritic Li growth. Here we report a practical thin (10–40 μm) Li/Mo/Li2Se with concurrently modulated interphase and mechanical properties, achieved via a scalable mechanical rolling process. The in situ generated Li2Se and Mo not only enhance the mechanical strength enabling the scalable fabrication of thin Li metal, but also promote homogeneous Li electrodeposition. Significantly, the Li/Mo/Li2Se demonstrates ultrahigh‐rate performance (15 mA cm−2) and ultralong‐lifespan cycling sustainability (2700 cycles) with exceptional anti‐pulverization capability. The Li|LiFePO4 cells show substantially prolonged cyclability over 1200 cycles with an ultralow decay rate of ~0.01 % per cycle. Moreover, the Li|LiNi0.8Co0.1Mn0.1O2 pouch cells deliver enhanced cycling stability even under the extremely harsh conditions of low negative‐to‐positive‐capacity (N/P) ratio of ~1.2 and lean electrolyte of ~0.95 g Ah−1, showing an exceptional energy density of 329.2 Wh kg−1. This work sheds light on facile pathway for scalable production of durable thin Li metal anode toward reliable practicability.

Boosting the Anode and Cathode Stability Simultaneously by Interfacial Engineering via Electrolyte Solvation Structure Regulation Toward Practical Aqueous Zn‐ion Battery

AbstractThe application of zinc‐ion batteries (ZIBs) is seriously challenged by the poor stability of Zn anode and cathode in aqueous solution, which is closely associated with electrolyte structure and water reactivity. Herein, the stability issues both for the cathode and anode can be simultaneously addressed via tuning the electrolyte solvation structure in hybrid electrolyte with tripropyl phosphate (TPP) as co‐solvent. On the Zn anode, a robust poly‐inorganic solid electrolyte interphase (SEI) layer comprised of Zn3(PO4)2‐ZnS‐ZnF2 species is in situ formed, effectively suppressing parasitic reaction and dendrite evolution. For V2O5 cathode, the notorious vanadium dissolution is effectively restricted with improved structure stability achieved. The optimized electrolyte facilitates the reversible redox kinetics both at the cathode and Zn anode. Consequently, Zn||Zn cells display extended cycling lifespans over 3000 h at 1 mA cm−2, 1 mAh cm−2. Zn||V2O5 full cells deliver a high reversible capacity of 261.8 mAh g−1 and hold retention of 73.6% upon 500 cycles even operated in harsh conditions with thin Zn anode (10 µm) and low negative/positive (N/P) ratio of ≈4.3, which also showcase impressive performance with regard to rate and storage performance, further emphasizing the potential of electrolyte regulation tactics in advancing the commercialization of ZIBs.

Comparison and optimization of electrochemical and thermal performances of SOFC with different configurations of a metal foam flow field

The effects of different configurations of a metal foam flow field on current density and temperature gradient of a single channel solid oxide fuel cell (SOFC) are investigated, and the overall performance of the optimum configuration is optimized. First, model A (conventional channel-rib flow field) is compared with three different configurations (i.e., model B with metal foam flow field only at anode, model C with that only at cathode, and model D at both). Although model C achieves the highest current density, its temperature is also fairly high. Although model B achieves the lowest temperature gradient, its current density is also fairly low. Model D performs well in both current density and temperature gradient. Then, the effect of electrode thickness and metal foam thickness on the performance of model D is investigated. The Ohmic polarization of model D remains almost constant with different electrode thicknesses, and its concentration polarization decreases as the electrode thickness decreases, which is totally different from the channel-rib flow field. Moreover, a thinner cathode causes lower activation overpotential, whereas a thinner anode causes higher activation overpotential. In general, a thick anode, a thin cathode, and thin metal foam can maximize the current density of model D, while a thick electrode and metal foam can always reduce the temperature gradient. Finally, the Taguchi method and gray relational analysis are used to optimize the current density and temperature gradient of model D. The current density of an optimized model is 3.27% higher than that of the original model with a temperature gradient of 9.05 K/cm.

Facile synthesis of tunable ultra-thin anodes for long-lasting and high-energy-density lithium metal batteries

Thin lithium metal anodes (LMAs) play a crucial role in realizing lithium metal batteries (LMBs) with high-energy–density. However, the commercial production of thin lithium anode continues to face challenges in manufacturing complexities, inadequate reversible capacity and unstable cyclability. Herein, we show a facile and effective strategy to produce ultra-thin LMAs with tunable thickness (10 ∼ 50 μm), in which the Li-Ag alloy is in-situ formed and uniformly loaded on the cellulose-derived carbon supported reduced graphene oxide (CC-rGO). Density functional theory (DFT) calculations reveal that the Li-Ag alloy has strong adsorption energy and minimal energy barrier for Li diffusion, which can effectively meliorate Li transfer and homogeneous deposition. Due to the advantages of the synergistic effect of Li-Ag alloy modification, the elaborate-designed ultra-thin and 3D structure, the CC-rGO/LixAgy/Li anode facilitates the acceleration of Li-ion transport kinetics, reduce the nucleation barrier and offer adequate active sites, thereby improving the electrochemical characteristics. The CC-rGO/LixAgy/Li symmetric cell exhibits stably Li plating/stripping for 5000 h at 1 mA cm−2. When matched with LiFePO4 cathode, the full cell delivers remarkable cycling reversibility for 900 cycles at 3C and the negative/positive capacity (N/P) ratio can be down to 1.18. More impressively, the pouch cell reveals an excellent flexibility with maintaining more than 80 % capacity over 80 cycles at 0.3C in folded states. This study provides a promising avenue to developing viable high-energy–density LMBs.

1 µm‐Thick Robust Gel Polymer Electrolyte with Excellent Interfacial Stability for High‐Performance Li Metal Batteries

AbstractGel polymer electrolytes (GPEs) hold great promise for lithium (Li) metal batteries (LMBs). Nevertheless, a critical challenge lies in reducing the thickness of GPEs while maintaining their mechanical integrity to achieve high‐energy‐density LMBs. Additionally, protecting the Li metal anode via electrolyte engineering in GPEs remains demanding. Herein, an innovative ultrathin (1 µm‐thick) yet robust GPE developed using an in situ curing technique, featuring a nanofibrous, exceptionally strong polyethylene separator is presented. The unique microstructure, interfacial conformability, and ultrahigh mechanical robustness of the ultrathin polyethylene separator are thoroughly verified. Enhanced ionic association within the GPE is achieved due to the strong affinity of electrolyte solvent with the fluorinated polymer network, as confirmed by large‐scale molecular dynamics simulations. The optimized solvation structure with high contact ion pairs and aggregate fractions contributes to forming an anion‐derived inorganic‐rich solid electrolyte interphase (SEI), thereby protecting the lithium anode. Benefiting from the ultrahigh robustness of GPE and the excellent interfacial stability, the Li metal full cell with a high mass loading LiNi0.8Co0.1Mn0.1O2 cathode (≈17.3 mg cm−2) and thin Li foil anode (50 µm) demonstrates 91% capacity retention after 200 cycles. This design demonstrates a feasible approach toward the practical quasi‐solid‐state LMBs.

(Invited) LIOVIX® Technology: Lithium Metal Anode Manufacturing at Scale

Next generation battery technologies critically depend on giga factory scale for production of the battery components, such as thin lithium anodes. The core of Livent innovative and sustainable solution is LIOVIX®, proprietary Printable Lithium Formulation. The ability to print lithium metal anodes opens the pathway for the various ranges of anode’s width and thickness and allows cell manufacturer to easier change cell design and format to meet application requirements.