Suppress Dendrite Growth Research Articles

3D Leaf-Like Copper-Zinc Alloy Enables Dendrite-Free Zinc Anode for Ultra-Long Life Aqueous Zinc Batteries.

Metallic zinc exhibits immense potential as an anode material for aqueous rechargeable zinc batteries due to its high theoretical capacity, low redox potential, and inherent safety. However, practical applications are hindered by dendrite formation and poor cycling stability. Herein, a facile substitution reaction method is presented to fabricate a 3D leaf-like Cu@Zn composite anode. This unique architecture, featuring a 3D network of leaf-like Cu on a Zn foil surface, significantly reduces nucleation overpotential and facilitates uniform Zn plating/stripping, effectively suppressing dendrite growth. Notably, an alloy layer of CuZn5 forms in situ on the 3D Cu layer during cycling. DFT calculations reveal that this CuZn5 alloy possesses a lower Zn binding energy compared to both Cu and Zn metal, further promoting Zn plating/stripping and enhancing electrochemical kinetics. Consequently, the symmetric Cu@Zn electrode exhibits remarkable cycling stability, surpassing 1300 h at 0.5mA cm-2 with negligible dendrite formation. Furthermore, full cells comprising Cu@Zn||VO2 exhibit superior capacity and rate performance compared to bare Zn anodes. This work provides a promising strategy for constructing highly stable and efficient Zn anodes for next-generation aqueous zinc batteries.

Phase-Field Modeling of Electrolyte Transport Properties and Elasticity Modulus in Suppression of Dendrite Growth in Solid-State-Lithium-Ion-Batteries

Dendrite formation in batteries is a critical issue that affects battery performance and lifespan. Solid-state electrolytes have gained attention due to their advantages such as compactness, higher energy density, and enhanced safety. This study investigates dendrite growth in batteries via phase field simulations utilizing a grand potential-based phase field model. The simulations are executed using the MOOSE (Multiphysics Object-Oriented Simulation Environment) framework, a Finite Element Method (FEM) based solver known for its modular approach and proficiency in handling complex multi-physics problems. Initially, the study considers a pure lithium anode and a 1M LiPF6 electrolyte for the liquid case. To explore the benefits of solid electrolytes, a fictitious solid electrolyte with transport properties similar to the liquid electrolyte but having different mechanical properties is considered. The mechanical impact resulting from the volume changes due to lithium deposition is not accounted for in the liquid electrolyte model. However, the solid electrolyte model addresses this by modifying the Butler-Volmer kinetics and incorporating the influence of stresses on the localized lithium deposition. Sensitivity analysis is performed for various parameters in both the liquid and solid electrolytes. The results indicate that dendrite growth is reduced with decreased applied over-potential and interfacial energies. For solid electrolytes, an additional parameter, increased Young’s modulus, contributes to reduced dendrite growth. The evaluation of dendrite growth involves quantifying surface roughness using the root mean square (RMS) approach. The elasticity modulus significantly influences dendrite formation, with higher values in materials like LLZO, and glass Li3PS4 exhibiting lower dendrite growth, while lower values in polymer-based materials like P(VDF-HFP) and PVDF/CAB/PE exhibit higher dendrite growth. The solid electrolyte acts as a crucial mechanical barrier, influencing the dendrite tip growth rate and ensuring uniform electrodeposition throughout the dendritic structure. Furthermore, the work investigates the impact of the cathode on dendrite growth. The contraction of the cathode provides additional space for dendrites to move, leading to reduced compressive stresses and increased dendrite growth. Conversely, higher compressive stresses suppress dendrite growth.

Advanced Hybrid Polymer/Ceramic PEO-SnF2 Protective Mechanism for Sodium Metal Anodes

In the face of mounting global energy requirements and pressing environmental issues, the scientific community turned to lithium-metal batteries, celebrated for their superior capacity and efficiency. However, challenges arising from the scarcity and increasing costs of lithium have redirected research efforts towards sodium batteries. Sodium metal anodes, with their remarkable theoretical specific capacity of ~1166 mAh/g, low anode potential of -2.714 V vs standard hydrogen electrode, and cost benefits, are increasingly recognized as promising candidates for conventional energy storage systems. Notwithstanding their advantages, the unstable and fragile solid electrolyte interphase (SEI) due to the spontaneous reaction between metallic Na and a liquid electrolyte remains a significant limitation. As this SEI layer expands, it hinders ion transport, causing increased polarization and diminishing the battery's energy efficiency. Specifically, during the plating process, Na ions are deposited beneath the SEI layer, causing significant expansion. This expansion fractures the fragile SEI, allowing dendrites to grow through these defects. As these dendrites grow, they can pierce the separator, posing a risk of short-circuiting the battery. While numerous studies have proposed designs for protecting sodium metal interphase, to overcome these challenges, this study amalgamates mechano-electrochemical protective strategies to enhance sodium metal anode stability, offering groundbreaking solutions to these challenges.Central to our exploration were tin fluoride (SnF2) and silicon nitride (Si3N4), both established as effective in generating robust artificial SEI layers on the sodium metal surface. These layers, rich in NaF and NaxN respectively, demonstrated a notable improvement in cycling performance, effectively suppressing dendrite growth and enhancing the battery's cycling stability by nearly 3.5 times compared to bare sodium anodes.Building upon these foundational insights, a novel approach was conceptualized: a hybrid protective mechanism combining polyethylene oxide (PEO) with the presence of SnF2 as an additive, is particularly efficacious. This combination was specifically chosen to provide chemical stability, morphological conformality, and mechanical flexibility to accommodate the mechano-electrochemical instability upon sodiation/desodiation processes. Through this novel strategy, we aimed to amalgamate the strengths of both components, ensuring optimal outcomes. This composite artificial SEI under a 0.25 mA/cm2 current density, delivers a cycling performance 10 times superior to bare sodium metal and survived up to 1800 hours of cycling. Impressively, at a high current density of 0.5 mA/cm2, the hybrid system still performed much better than its untreated counterpart and continued cycling for up to 800 hours of cycling. The synergy of PEO and SnF2 remarkably minimized electrolyte decomposition, inhibited dendrite formation, and stabilized Na plating/stripping processes, all of which consolidated its promise for sodium metal battery technology.

A 5 V Ultrahigh Energy Density Lithium Metal Capacitor Enabled by the Fluorinated Electrolyte

Lithium metal capacitor (LMC), incorporating a redox-type lithium metal anode and a capacitive-type carbon cathode, delivers a combination of high energy and power characteristics, which is regarded as a promising electrochemical energy storage system. However, the unstable interface stability of lithium anode and the unclear capacitive mechanism of carbon cathode seriously restrict the advancement of LMC. Herein, an all-fluorinated electrolyte with high voltage stability has been designed for engineering 5 V LMC. It is noticed that a high-quality LiF-rich solid electrolyte interphase derived from all-fluorinated electrolyte effectively improves the interfacial stability of lithium metal anode, boosting the reversible Li plating/stripping behavior and suppressing dendrite growth. Moreover, analyzed by the thermodynamic perspective, the stable PF6−(FEC)2(FEMC)4 configuration with the lowest solvation energy mainly exists in the all-fluorinated electrolyte, which reveals that the suitable pore size distribution (1.3–4.6 nm) can ensure the strong adsorption/desorption process. Endowed by the all-fluorinated electrolyte, the established 5 V LMC paired with an optimized porous carbon sheet cathode manifests excellent electrochemical performances with an ultrahigh energy density of 537.6 Wh kgcathode−1 and a large power density of 17500 W kgcathode−1. This elaborate work affords in-depth insights based on fluorinated electrolyte strategy into the fabrication guidance of LMC.

Experimental research of electrolyte additives and battery performance of aqueous zinc-ion batteries

Abstract Aqueous zinc-ion batteries (AZBs) have received increasing attention due to their high safety, high theoretical specific capacity, and abundant resources. However, the problems of zinc anode dendrite growth, hydrogen precipitation corrosion, and irreversible side reactions in AZIBs have restricted their application process. Electrolyte additives are an effective way to solve problems. This work looked at what would happen when 4-(2-hydroxyethyl) piperazine-1-ethane sulfonic acid (HEPES) was added to the ZnSO4 solution, which is the electrolyte. It was tested on AZIBs by using coin batteries as the carriers and adding HEPES to the electrolyte. The findings demonstrated that the electrolyte exhibited robust stability following HEPES addition, effectively suppressing dendrite growth through electric field modulation at the zinc anode. Incorporating 8 mM HEPES notably enhanced battery cycle longevity to over 240 hours under conditions of 0.2 mA cm−2 and 0.2 mAh cm−2. The HEPES additive was found to be effective in improving the rate capability through the testing of Zn||Zn symmetric batteries. This work provides a feasible idea for the performance improvement of low-cost and high-efficiency AZIBs.

Unraveling the Role and Impact of Alumina on the Nucleation and Reversibility of β‐LiAl in Aluminum Anode Based Lithium‐Ion Batteries

AbstractAluminum, due to its high abundance, very attractive theoretical capacity, low cost, low (de−) lithiation potential, light weight, and effective suppression of dendrite growth, is considered as a promising anode candidate for lithium‐ion batteries (LIBs). However, its practical application is hindered due to multiple detrimental challenges, including the formation of an amorphous surface oxide layer, pulverization, and insufficient lithium diffusion kinetics in the α‐phase. These outstanding intrinsic challenges need to be addressed to facilitate the commercial production of Al‐based batteries. The native passivation layer, Al2O3, plays a critical role in the nucleation and reversibility of lithiating aluminum and is thoroughly investigated in this study using high precision electrochemical micro calorimetry. The enthalpy of crystallization of β‐LiAl is found to be 40.5 kJ mol−1, which is in a strong agreement with the value obtained by calculation using Nernst equation (40.04 kJ mol−1). Surface treatment of the active material by the addition of 25 nm of alumina increases the nucleation energy barrier by 83 % over the native oxide layer. After the initial nucleation, the added alumina does not negatively impact the reversibility at 0.1 C rate, suggesting the removal of alumina is not necessary for improving the cyclability of aluminum anode based lithium‐ion batteries. Moreover, the coulombic efficiencies are also found to be slightly higher in the alumina treated samples compared to the untreated ones.

Amorphous High‐Entropy Alloy Interphase for Stable Lithium Metal Batteries

AbstractThe unstable anode/electrolyte interphase induces severe lithium dendrite growth hindering the practical application of lithium metal batteries. The lithium alloy interphase presents a promising strategy for regulating Li+ plating/stripping behavior. However, binary or ternary alloys are insufficient to address various challenges in lithium metal batteries and the high temperature required for alloy preparation hampers their direct applications on lithium metal surfaces. In this study, a high‐entropy alloy (HEA) interphase is developed on lithium metal surfaces via room‐temperature magnetron sputtering, showcasing multifunctional advantages in regulating Li+ plating/stripping behavior. The cocktail effect of the (HEA) facilitated the formation of a homogeneous amorphous interphase with abundant lithiophilic sites and magnetic properties, promoting uniform Li+ nucleation and deposition. Furthermore, the high mechanical strength and corrosion resistance of HEA provided physicochemical stability for the lithium anode interphase, consistently suppressing dendrite growth. Consequently, lithium metal anodes with HEA interphases exhibited robust cycling performance lasting over 4000 h at 2 mA cm−2. The LFP full battery demonstrated high‐capacity retention of 90% with an average Coulombic efficiency of 99.7%. Thus, the HEA interphases on lithium metal surfaces offer controllable regulation of Li+ deposition behavior through high‐entropy manipulation, opening novel strategies for stable lithium metal batteries.

Rational design of hybrid electrolyte for all-solid-state lithium battery based on investigation of lithium-ion transport mechanism

Lithium all-solid-state batteries (ASSBs) are a promising technology for achieving high energy density, long cycle life, and safe rechargeable battery systems. Among these, Li ASSBs using solid polymer electrolytes (SPEs) have gained attention owing to their processability, lightweight nature, flexibility, and favorable electrode contacts. However, SPEs have low ionic conductivity, low Li+ transference number, and lack mechanical strength, limiting cell performance. Therefore, the present study focuses on the development of hybrid polymer electrolytes (HPEs) by incorporating Li1+xAlxTi2-x(PO4)3 (LATP) of Li/Na superionic conductor-type materials into SPEs. The HPEs with LATP 10 wt% exhibited significant improvements with an ionic conductivity of 7.23 × 10−4 S cm−1 at 45 °C and a Li+ transference number of 0.61. Density functional theory calculations supported the enhanced Li-ion migration through the polymer-LATP interface achieved by the optimized LATP content. The addition of LATP particles enhanced the mechanical strength of the electrolytes, effectively suppressing dendrite growth, resulting in a 66.65 % capacity retention after 320 cycles, highlighting the crucial role of high-performance HPEs in advanced ASSBs. By addressing the limitations of SPEs, HPEs offer promising opportunities to unlock the full potential of solid-state battery technologies for various energy storage systems.

Amorphous FeSnOx Nanosheets with Hierarchical Vacancies for Room-Temperature Sodium-Sulfur Batteries.

Room-temperature sodium-sulfur (RT Na-S) batteries, noted for their low material costs and high energy density, are emerging as a promising alternative to lithium-ion batteries (LIBs) in various applications including power grids and standalone renewable energy systems. These batteries are commonly assembled with glass fiber membranes, which face significant challenges like the dissolution of polysulfides, sluggish sulfur conversion kinetics, and the growth of Na dendrites. Here, we develop an amorphous two-dimensional (2D) iron tin oxide (A-FeSnOx) nanosheet with hierarchical vacancies, including abundant oxygen vacancies (Ovs) and nano-sized perforations, that can be assembled into a multifunctional layer overlaying commercial separators for RT Na-S batteries. The Ovs offer strong adsorption and abundant catalytic sites for polysulfides, while the defect concentration is finely tuned to elucidate the polysulfides conversion mechanisms. The nano-sized perforations aid in regulating Na ions transport, resulting in uniform Na deposition. Moreover, the strategic addition of trace amounts of Ti3C2 (MXene) forms an amorphous/crystalline (A/C) interface that significantly improves the mechanical properties of the separator and suppresses dendrite growth. As a result, the task-specific layer achieves ultra-light (~0.1 mg cm-2), ultra-thin (~200 nm), and ultra-robust (modulus=4.9 GPa) characteristics. Consequently, the RT Na-S battery maintained a high capacity of 610.3 mAh g-1 and an average Coulombic efficiency of 99.9 % after 400 cycles at 0.5 C.

Amorphous FeSnOx Nanosheets with Hierarchical Vacancies for Room‐Temperature Sodium‐Sulfur Batteries

AbstractRoom‐temperature sodium‐sulfur (RT Na−S) batteries, noted for their low material costs and high energy density, are emerging as a promising alternative to lithium‐ion batteries (LIBs) in various applications including power grids and standalone renewable energy systems. These batteries are commonly assembled with glass fiber membranes, which face significant challenges like the dissolution of polysulfides, sluggish sulfur conversion kinetics, and the growth of Na dendrites. Here, we develop an amorphous two‐dimensional (2D) iron tin oxide (A‐FeSnOx) nanosheet with hierarchical vacancies, including abundant oxygen vacancies (Ovs) and nano‐sized perforations, that can be assembled into a multifunctional layer overlaying commercial separators for RT Na−S batteries. The Ovs offer strong adsorption and abundant catalytic sites for polysulfides, while the defect concentration is finely tuned to elucidate the polysulfides conversion mechanisms. The nano‐sized perforations aid in regulating Na ions transport, resulting in uniform Na deposition. Moreover, the strategic addition of trace amounts of Ti3C2 (MXene) forms an amorphous/crystalline (A/C) interface that significantly improves the mechanical properties of the separator and suppresses dendrite growth. As a result, the task‐specific layer achieves ultra‐light (~0.1 mg cm−2), ultra‐thin (~200 nm), and ultra‐robust (modulus=4.9 GPa) characteristics. Consequently, the RT Na−S battery maintained a high capacity of 610.3 mAh g−1 and an average Coulombic efficiency of 99.9 % after 400 cycles at 0.5 C.

Effects of solid electrolyte particle size and silver-carbon interlayer on lithium deposition in all-solid-state lithium-metal batteries

All-solid-state batteries with lithium-metal anodes are expected to exhibit high performance. For practical application, the growth of lithium dendrites must be suppressed. One method to suppress dendrite growth is to insert a carbon interlayer at the interface between the anode and solid electrolyte (SE). Dendrite growth is related to the anode interface properties and depends on the SE particle size used in the SE layer. Appropriate control of the SE particle size used at the anode interface can improve battery performance. In this study, the effects of SE particle size and carbon interlayer type on lithium-metal deposition morphology are investigated by X-ray CT measurement. The results show that dendrite growth is suppressed when the small-particle SE is used owing to the smaller pores between the SE layer and carbon interlayer. In addition, by controlling the SE particle size distribution using a double SE layer, both high ionic conductivity and dendrite suppression can be achieved. Furthermore, dendrite growth can be suppressed using a silver particle-added carbon interlayer, even with the large-particle SE where dendrites are prone to grow more easily.

Anti-corrosive and carbonyl-rich interlayer enables highly reversible zinc anode

Aqueous zinc ion batteries (AZIBs) are considered as highly promising candidates for large-scale energy storage due to their exceptional safety profile, environmental sustainability, and cost-effectiveness. However, the progress of AZIBs is impeded by several challenges including the formation of zinc dendrites, self-corrosion issues, and hydrogen evolution. Herein, we demonstrate the in-situ fabrication of a hydrophobic and carbonyl-rich zinc phthalate (ZCHO) solid electrolyte interphase (SEI) layer on the zinc foil through a facile liquid deposition method. The incorporation of carbonyls into the ZCHO layer enhances ion migration dynamics by attracting Zn2+, while also promoting preferential deposition onto the (002) surface, effectively mitigating water-induced corrosion and hydrogen evolution, likewise reducing charge transfer resistance. These inherent advantages contribute to a homogeneous distribution of Zn2+ concentration on the zinc anode surface, thereby suppressing dendrite growth. The results demonstrate that the symmetric battery exhibits an impressive cycle life of over 2300 h under a current density of 1 mA cm−2, with an areal capacity of 0.5 mAh cm−2. Additionally, it demonstrates stable cycling for more than 700 h at 5 mA cm−2, 0.25 mAh cm−2. Furthermore, when assembled with NH4V4O10, the full battery delivers a specific capacity of 222.9 mAh g−1 after undergoing 1000 cycles under a current density of 5 A g−1 while maintaining a capacity retention rate of 86.26 %. This study presents a novel and facile approach to advance research on high-performance AZIBs.

Isomeric dichloropyrazine of dual-function additives: Synergistic enhancement of lithium anode protection and sulfur redox kinetics in lithium–sulfur batteries

Lithium-sulfur batteries (LSBs) currently face challenges such as low sulfur utilization, inadequate cycling stability, and unstable lithium anode interfaces. In this study, dichloropyrazines (DCPs) are introduced as dual-functional additives into electrolyte and 2,5-DCP exhibits the most promising performance enhancement. This superiority can be attributed to its strong redox activity, lower molecular orbital energy gap, and more negative relative binding energy compared to the other DCP isomers. Specifically, DCPs demonstrate their dual functionality by promoting the formation of a stable organic-inorganic hybrid solid electrolyte interface (SEI) rich in LiCl on lithium anodes. This ensures uniform lithium deposition and suppresses dendrite growth. At sulfur cathodes, density functional theory (DFT) calculations confirm that DCPs facilitate lithium polysulfides (LiPSs) conversion kinetics through Li–N bond formation. LSBs with 2,5-DCP exhibit excellent stability at a 1C rate and retain 86.6 % capacity after 800 cycles. This study demonstrates DCPs' potential as effective dual-functional electrolyte additives in designing high-performance LSBs.

Anion trapping-coupling strategy driven asymmetric nonflammable gel electrolyte for high performance sodium batteries

Gel polymer electrolytes, promising electrolyte candidates for advanced sodium metal batteries (SMBs), suffer from the great challenges of combustion risk and inferior interfacial stability caused by poor mechanical properties and low Na+ selectivity. Herein, we proposed a rational anion trapping-coupling strategy to build a mechanically robust asymmetric nonflammable composite gel electrolyte (AS-NFCGE) by introducing in-situ coupled boron nitride nanosheets (BNNs) on glass fiber matrix embedded with synchronous polymerized flame-retardant polymer. Theoretical calculations, finite-element simulations, and experimental tests prove that the high coupling BNNs with anion trapping effect constructed asymmetric structure can significantly accelerate selective Na+ migration kinetics, enhance mechanical properties of AS-NFCGE and endow a similar single-ion conducting behavior to homogenize ion-distribution at the anode side, thus improving interfacial stability and suppressing dendrite growth to achieve ultra-stable SMBs. Specifically, the AS-NFGE delivers high ionic conductivity and Na+ transference number (0.73) together with excellent flam-retardant. Consequently, the dendrite-free Na/Na symmetric cell exhibits considerable cycling life for over 3000 h at 0.1 mA cm−2 with low overvoltage. Applications of the AS-NFCGE in SMBs further demonstrate the excellent electrochemical performances, and no thermal runaway and no electrolyte leakage occur for pouch cells using AS-NFCGE. This strategy provides new insight into the development of safe and high-energy SMBs and the beyond.

Water-Capture Filter Paper Separator Realizing Ambient Li-Air Battery.

Lithium-air battery (LAB) is regarded as one of the most promising energy storage systems. However, the challenges arising from the lithium metal anode have significantly impeded the progress of LAB development. In this study, cellulose-based filter paper (FP) is utilized as a separator for ambient Li-air batteries to suppress dendrite growth and prevent H2O crossover. Thermogravimetric analysis and molecular spectrum reveal that FP enables ambient Li-air battery operation due to its surface functional groups derived from cellulose. The oxygen-enriched surface of cellulose not only enhances ion conductivity but also captures water and confines solvent molecules, thereby mitigating anode corrosion and side reactions. Compared with commercial glassfiber (GF) separator, this cellulose-based FP separator is cheaper, renewable, and environmentally friendly. Moreover, it requires less electrolyte while achieving prolonged and stable cycle life under real air environment conditions. This work presents a novel approach to realizing practical Li-air batteries by capturing water on the separator's surface. It also provides insights into the exploration and design of separators for enabling practical Li-air batteries toward their commercialization.

Extension of Aqueous Zinc Battery Life Using a Robust and Hydrophilic Polymer Separator

AbstractThe use of zinc (Zn) metal as an anode in aqueous batteries offers an eco‐friendly and cost‐effective energy storage solution. However, Zn dendrite formation severely restricts the cycle life of the battery toward practical application. Herein, a commercially hydrophilic polytetrafluoroethylene (PTFE) membrane is demonstrated as a separator to significantly extend the cycle life of the Zn metal anode. In contrast with the conventional fragile glass fiber separator, a wetted PTFE separator exhibited high mechanical strength (stress of 34.3 MPa at 41.4% strain) and favorable hydrophilicity, which both efficiently suppress dendrite growth. The uniform and robust pore structures are proven to facilitate a homogeneous Zn2+ ion flux and a high transfer number of Zn2+ (0.81), which has guaranteed reversible Zn plating/stripping. As a proof of concept, the PTFE separator extended the cycle life considerably to over 3000 h and promoted a Zn plating/stripping efficiency of 99.5% in the unmodified 2 m ZnSO4 aqueous electrolyte. This advancement underscores the significant potential of the PTFE separator for enhancement of the cycling durability of aqueous zinc‐ion batteries (AZIBs).

Constructing Highly Stable Zinc Metal Anodes via Induced Zn(002) Growth.

The nonuniform electric field at the surface of a zinc (Zn) anode, coupled with water-induced parasitic reactions, exacerbates the growth of Zn dendrites, presenting a significant impediment to large-scale energy storage in aqueous Zn-ion batteries. One of the most convenient strategies for mitigating dendrite-related issues involves controlling crystal growth through electrolyte additives. Herein, we present thiamine hydrochloride (THC) as an electrolyte additive capable of effectively stabilizing the preferential deposition of the Zn(002) plane. First-principles calculations reveal that THC tends to adsorb on Zn(100) and Zn(101) planes and is capable of inducing the deposition of Zn ion onto the (002) plane and the preferential growth of the (002) plane, resulting in a flat and compact deposition layer. A THC additive not only effectively suppresses dendrite growth but also prevents the generation of side reactions and hydrogen evolution reaction. Consequently, the Zn||Zn symmetric battery exhibits long-term cycling stability of over 3000 h at 1 mA cm-2/1 mAh cm-2 and 1000 h at 10 mA cm-2/10 mAh cm-2. Furthermore, the NH4V4O10||Zn full battery also displays excellent cycling stability and a high reversible capacity of 210 mAh g-1 after 1000 cycles at 1 A g-1, highlighting a significant potential for practical applications.

In Situ Forming Na─Sn Alloy/Na2S Interface Layer for Ultrastable Solid State Sodium Batteries

AbstractThe poor interfacial compatibility between sodium superionic conductor (NASICON) electrolyte and metallic sodium anode will lead to severe dendrite penetration, impeding the application of NASICON electrolytes for solid state sodium batteries. Herein, a homogeneous SnS2 coating layer is sputtered on the surface of Na3.4Zn0.1Zr1.9Si2.2P0.8O12 electrolyte to in situ construct a kinetically stable Na─Sn alloy/Na2S interlayer, possessing superior Na affinity, low diffusion barrier, and electronic insulating character to suppress dendrite growth, which is confirmed by experiments and density‐functional theory calculations. Benefiting from the Na─Sn alloy/Na2S interphase, the critical current density of Na3.4Zn0.1Zr1.9Si2.2P0.8O12 increases from 2.4 to 9.4 mA cm−2. In addition, the obtained Na3V2(PO4)3/Na3.4Zn0.1Zr1.9Si2.2P0.8O12@SnS2/Na solid state batteries exhibit a high initial reversible discharge capacity of 115.1 mAh g−1 at 0.1 °C with an initial Coulombic efficiency of 93.6%, and a capacity retention rate of 88.1% after 1000 cycles at 1 C.

β''-Al2O3 protecting layer for stable zinc metal anodes

Aqueous zinc-ion batteries (AZIB) has attracted considerable attention on account of its low cost, high security and environmental friendliness. Nevertheless, the growing dendrites and corrosion reactions on the surface of zinc anode limit the development of AZIB. Herein, β''-Al2O3 with high ion conductivity was firstly employed as an efficient artificial layer for stabilizing the zinc anode. The optimized β''-Al2O3 layer enables homogeneous ion flux and uniform zinc deposition, significantly suppressing dendrite growth and parasitic reactions. Symmetric cells based on this unique protective layer can stably operate for 1600 h under 1 mA cm−2/1 mAh cm−2. Benefiting from the high-performance zinc metal anode, the full cell paired with the NH4V4O10 cathode delivers a high discharge initial capacity of 400 mAh g−1 at 1 A g−1 and good cycling stability. This simple protecting layer provides a new strategy for the modification of zinc metal anode and accelerates the practical application of AZIB.

Ultralong Cycling and Safe Lithium-Sulfur Pouch Cells for Sustainable Energy Storage.

While layered metal oxides remain the dominant cathode materials for the state-of-the-art lithium-ion batteries, conversion-type cathodes such as sulfur present unique opportunities in developing cheaper, safer, and more energy-dense next-generation battery technologies. There has been remarkable progress in advancing the laboratory scale lithium-sulfur (Li-S) coin cells to a high level of performance. However, the relevant strategies cannot be readily translated to practical cell formats such as pouch cells and even battery pack. Here these key technical challenges are addressed by molecular engineering of the Li metal for hydrophobicization, fluorination and thus favorable anode chemistry. The introduced tris(2,4-di-tert-butylphenyl) phosphite (TBP) and tetrabutylammonium fluoride (TBA+F-) as well as cellulose membrane by rolling enables the formation of a functional thin layer that eliminates the vulnerability of Li metal towards the already demanding environment required (1.55% relative humidity) for cell production and gives rise to LiF-rich solid electrolyte interphase (SEI) to suppress dendrite growth. As a result, Li-S pouch cells assembled at a pilot production line survive 400 full charge/discharge cycles with an average Coulombic efficiency of 99.55% and impressive rate performance of 1.5 C. A cell-level energy density of 417Wh kg-1 and power density of 2766W kg-1 are also delivered via multilayer Li-S pouch cell. The Li-S battery pack can even power an unmanned aerial vehicle of 3kg for a fairly long flight time. This work represents a big step forward acceleration in Li-S battery marketization for future energy storage featuring improved safety, sustainability, higher energy density as well as reduced cost.