Approaching 100% Comprehensive Utilization Rate of Ultra-Stable Zn Metal Anodes by Constructing Chitosan-Based Homologous Gel/Solid Synergistic Interface

Aqueous Zn–metal batteries are considered promising candidates for next-generation energy storage. However, low zinc utilization rate (ZUR) and limited cycle life are still hinder its commercial application because of severe parasitic side effects. Herein, inspired by the wound healing process, an innovative electrode recovery technology is developed to improve the comprehensive ZUR and prolong the cycling life through repetitive rejuvenation of zinc anode by designing chitosan-based homologous gel/solid synergistic electrolyte. The designed synergistic electrolyte, consisting of protonated chitosan gel electrolyte and Zn-chitosan solid electrolyte, exhibits superior zinc ion diffusion capability and low free-water activity, leading to dendrite-free Zn deposition and HER inhibition. Moreover, through proton neutralization and zinc ion complexation, the formulated electrolyte can implement the rejuvenation of zinc anode by smoothing interfacial defects and eliminating parasitic byproducts. Consequently, the gel/solid synergistic electrolyte displays reversible Zn plating/stripping chemistry for 4000 cycles with high average Coulombic efficiency (99.8%) and realizes comprehensive ZUR of 97.4% through four iterations of electrode recover under extreme conditions (20 mA cm⁻², 31.5% Zn depth of discharge), noticeably higher than zinc electrode with no recover (11.8%). Furthermore, the superiority of customized synergistic electrolyte is further demonstrated by coupling with I₂ cathode and achieving impressive 36 000 stable cycles.     

Hexafluoroisopropyl Trifluoromethanesulfonate-Driven Easily Li+ Desolvated Electrolyte to Afford Li||NCM811 Cells with Efficient Anode/Cathode Electrolyte Interphases

Solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI) with optimized components and structures are considered to be crucial for lithium-ion batteries. Here, gradient lithium oxysulfide (Li₂SO_x, x = 0, 3, 4)/uniform lithium fluoride (LiF)-type SEI is designed in situ by using hexafluoroisopropyl trifluoromethanesulfonate (HFPTf) as electrolyte additive. HFPTf is more likely to be reduced on the surface of Li anode in electrolytes due to its high reduction potential. Moreover, HFPTf can make Li⁺ desolvated easily, leading to the increase in the flux of Li⁺ on the surface of Li anode to avoid the growth of Li dendrites. Thus, the cycling stability of Li||Li symmetric cells is improved to be 1000 h at 0.5 mA cm⁻². In addition, HFPTf-contained electrolyte could make Li||NCM811 batteries with a capacity retention of 70% after 150 cycles at 100 mA g⁻¹, which is attributed to the formation of uniform and stable CEI on the cathode surface for hindering the dissolvation of metal ions from the cathode. This study provides effective insights on the strong ability of additives to adjust electrolytes in “one phase and two interphases” (electrolyte and SEI/CEI).     

Nanofluid Electrolyte with Fumed Al2O3 Additive Strengthening Zincophilic and Stable Surface of Zinc Anode toward Flexible Zinc–Nickel Batteries

Flexible zinc–nickel batteries (FZNBs) have been considered as a promising power supply for wearable electronics due to the intrinsic safety, high operating voltage and superior rate performance. However, the serious self-corrosion of zinc and the redistribution of dissolved [Zn(OH)₄]²⁻ on the electrode surface limit the electrochemical performance of FZNBs. Herein, the nanofluid electrolyte with fumed Al₂O₃ additive is introduced into FZNBs and a protective layer is formed due to the adsorption of Al₂O₃ on the electrodeposited zinc anode. The protective layer strengthens the zincophilicity of the anode and homogenizes the deposition of [Zn(OH)₄]²⁻, avoiding the dendrite formation and the shape change of electrode. Meanwhile, by suppressing the [Zn(OH)₄]²⁻ diffusion from the anode surface to the bulk electrolyte, the interface stabilization is effectively promoted, thereby improving zinc utilization rate and inhibiting the corrosion. Hence, the FZNBs assembled with Al₂O₃-nanofluid electrolyte and electrodeposited zinc anode demonstrates superior energy density of 210 Wh L⁻¹ with a stable cycling of 575 h. Furthermore, FZNBs modified with Al₂O₃-nanofluid electrolyte have a promising future in the field of wearable and portable electronics.     

Perfluoro Macrocyclic Ether as an Ambifunctional Additive for High-Performance SiO and Nickel 88%-Based High-Energy Li-ion Battery

State-of-the-art lithium (Li)-ion batteries employ silicon anode active material at a limited fraction while strongly relying on fluoroethylene carbonate (FEC) electrolyte additive exceeding 10 wt.% to enable stable cycling. The swelling issue of silicon in the aspect of solid electrolyte interphase (SEI) instability and a risk of safety hazards and high manufacturing cost due to FEC has motivated the authors to design a well-working fluorinated additive substitute. High-capacity cells employing nickel-rich oxide cathode are pursued by operating at > 4.2 V versus Li/Li⁺, for which anodic stability of electrolyte is required. Herein, a highly effective new ambifunctional additive of icosafluoro-15-crown 5-ether is proposed at a little fraction of 0.4 wt.% for the stabilized interfaces and reduced swelling of high capacity (3.5 mAh cm⁻²) 5 wt.% SiO-graphite anode and LiNi_0.88Co_0.08Mn_0.04O₂ cathode. Utilizing together with a lowered fraction of FEC, reversible long 300 cycles at 4.35 V and 1 C (225 mA g⁻¹) are achieved. Material characterization results reveal that such stabilization is derived from the surface passivation of both anode and cathode with perfluoro ether, LiF, and Li_xPF_y species. The present study gives insight into electrolyte formulation design with lower cost and both-side stabilization strategies for silicon and nickel-rich active materials and their interfaces.     

Stable Non-flammable Phosphate Electrolyte for Lithium Metal Batteries via Solvation Regulation by the Additive

The application of lithium metal batteries (LMBs) is impeded by safety concerns. Employing non-flammable electrolytes can improve battery reliability while the cost and performance deterioration limit their popularization. Herein, a high-performance non-flammable electrolyte is designed, 1.5 m LiTFSI in propylene carbonate (PC)/triethyl phosphate (TEP) (4:1 by vol.) with 4-nitrophenyl trifluoroacetate (TFANP) as the additive, which can facilitate the construction of LiF-rich solid electrolyte interphase (SEI) on Li anode surface and cathode electrolyte interphase (CEI) on cathode surface through its prioritized decomposition. In TFANP-containing electrolyte, the decreased TEP coordination number in the solvation sheath relieves the adverse effect of active TEP on both the SEI and CEI for suppressing the growth of Li dendrites and reducing the continuous electrolyte consumption. Thus, the Li||LiNi_0.6Co_0.2Mn_0.2O₂ battery with such an electrolyte can deliver 132 mAh g⁻¹ after 150 cycles with high coulombic efficiency (99.5%) and superior rate performance (110 mAh g⁻¹ at 5 C, 1 C = 200 mA g⁻¹). This work provides a new additive insight on non-flammable electrolyte for reliable LMBs.     

Ultrafast Charging of a 4.8 V Manganese-Rich Cathode-Based Lithium Metal Cell by Constructing Robust Solid Electrolyte Interphases

Fast charging of Li-metal battery (LMB) is a challenging issue owing to the interfacial instability of Li-metal anode in liquid electrolyte and Li-dendrites growth, resulting in fire hazard. Those issues motivated to pioneer a stabilization strategy of liquid electrolyte-derived solid electrolyte interphase (SEI) layer that enables dendrites-free Li-metal anode under extremely high current density, which solid-state battery cannot. Here, the novel electrolyte formulation is reported including trace-level pentafluoropropionic anhydride (PFPA) combined with fluoroethylene carbonate (FEC) additives, and the SEI stabilization in Li//Mn-rich LMB, achieving unprecedented ultrafast charging under simultaneous extreme conditions of 20 C (charged in 3 min), 4.8 V and 45 °C, delivering 118 mAh g⁻¹ for long reversible 400 cycles, and unprecedented high stability of Li//Li cell under extremely high current 10 mA cm⁻² (Li stripping/plating in 6 min) for a prolonged time of 200 h. The SEI analysis results reveal that the PFPA, which has a symmetric 10 F-containing molecular structure, is a strong F source for promptly producing thin, uniform, and robust F- and organics-enriched SEI layers at both Li-metal anode and Mn-rich cathode, preventing Li-dendrites. This study provides a potential concept for ultrafast charging, long-cycled, and safer high-energy LMBs and LIBs.     

Hydrofluoric Acid-Removable Additive Optimizing Electrode Electrolyte Interphases with Li+ Conductive Moieties for 4.5 V Lithium Metal Batteries

High-voltage lithium metal batteries (LMBs) are capable to achieve the increasing energy density. However, their cycling life is seriously affected by unstable electrolyte/electrode interfaces and capacity instability at high voltage. Herein, a hydrofluoric acid (HF)-removable additive is proposed to optimize electrode electrolyte interphases for addressing the above issues. N, N-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) aniline (DMPATMB) is used as the electrolyte additive to induce PF₆⁻ decomposition to form a dense and robust LiF-rich solid electrolyte interphase (SEI) for suppressing Li dendrite growth. Moreover, DMPATMB can help to form highly Li⁺ conductive Li₃N and LiBO₂, which can boost the Li⁺ transport across SEI and cathode electrolyte interphase (CEI). In addition, DMPATMB can scavenge traced HF in the electrolyte to protect both SEI and CEI from the corrosion. As expected, 4.5 V Li|| LiNi_0.6Co_0.2Mn_0.2O₂ batteries with such electrolyte deliver 145 mAh g⁻¹ after 140 cycles at 200 mA g⁻¹. This work provides a novel insight into high-voltage electrolyte additives for LMBs.     

Phosphonium Bromides Regulating Solid Electrolyte Interphase Components and Optimizing Solvation Sheath Structure for Suppressing Lithium Dendrite Growth

Electrolyte additives play important roles in suppressing lithium dendrite growth and improving the electrochemical performance of long-life lithium metal batteries (LMBs), however, it is still challenging to design individual additive for adjusting the solid electrolyte interphase (SEI) components and changing lithium ion solvation sheath in the electrolyte at the same time for optimizing electrochemical performance. Herein, alkyl-triphenyl-phosphonium bromides (alkyl-TPPB) are designed as the electrolyte additive to enhance the stability of metallic Li anode under the guidance of multi-factor principle for electrolyte additive molecule design (EDMD). Both alkyl-TPP cations and Br⁻ anions produce positive influences on suppressing Li dendrite growth and stabilizing the unstable interphase between metallic Li anode/electrolyte. As expected, the optimized solvation sheath structure, and the stable SEI suppress Li dendrite growth. As a result, the Li||Li₄Ti₅O₁₂ cell reveals a long stable life over 1000 cycles with high Coulombic efficiency (99.9%). This work provides an insight on stabilizing SEI and optimizing solvation sheath structure with novel approach to develop long-term stability and safety LMBs.     

Low-Cost,Safe, and Ultra-Long Cycle Life Zn–K Hybrid Ion Batteries

Zinc-ion batteries (ZIBs) are viewed as a promising energy storage system for large-scale applications thanks to the low cost and wide accessibility of Zn-based materials, the high theoretical capacity of Zn anode, and their high level of safety. However, the practical application of ZIBs is hindered by the rapid performance degradation. Herein, a Zn–K hybrid ion battery design is proposed using a high-quality Prussian blue cathode and a nonflammable Zn–K hybrid ion electrolyte. The electrochemical process is divided into two parts, with K⁺ insertion/extraction occurring at the cathode side and Zn²⁺ plating/stripping occurring at the anode side, which avoids structure destruction caused by Zn²⁺ insertion in the cathode. The non-flammable electrolyte not only ensures high safety but also effectively suppresses dendrite growth on the Zn anode. The hybrid cells demonstrate a high capacity of 151.0 mAh g⁻¹, a high voltage of 1.74 V (vs Zn²⁺/Zn), and an ultra-long cycle life of 15 000 cycles. Combining the nonflammable nature of the electrolyte, the abundance of raw materials, and good electrochemical performance, the Zn–K hybrid ion battery system promises a promising future for renewable energy storage applications.     

Outer Helmholtz Plane Regulation and In Situ Zn Surface Reconstruction for Highly Reversible Zn Anodes

Metallic Zn, a promising anode for aqueous energy storage devices, suffers from uncontrolled dendrite growth and corrosion, leading to a short cycle life and low Coulombic efficiency (CE) in Zn-based batteries. Herein, a composite electrolyte including zinc sulfate, copper(II) chloride, and poly(N-diallyldimethylammonium chloride) (PDADMAC), denoted as PDADMAC–CuCl₂–ZnSO₄, is applied to simultaneously reconstruct the outer Helmholtz plane (OHP) and homogenize the Zn surface for highly reversible Zn anodes. The results of characterization, namely Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, density functional theory calculations, and electrochemical tests, confirm that the addition of chloride ions promotes the adsorption of PDADMAC on the OHP of the electric double layer and controls the Zn deposition process by regulating the electric field. Simultaneously, in situ Zn surface homogenization is accomplished by the reaction of Cu²⁺ on the Zn surface. As a result, the highly reversible Zn anode sustains extremely long-term cycling for 2407 h at 5 mA cm⁻² with 5 mAh cm⁻² and 1300 h at 10 mA cm⁻² with 10 mAh cm⁻² in Zn//Zn symmetrical cells. A high average CE of 99.3% is achieved over 430 cycles at 15% depth of discharge.     

Stabilization of Zn Metal Anode through Surface Reconstruction of a Cerium-Based Conversion Film

Corrosion and dendritic deposition have been the long-standing interfacial challenges of Zn anode, resulting in the deterioration of the aqueous zinc-based batteries. Herein, the surface of Zn metal anode is pioneeringly reconstructed by a cerium-based conversion film (Zn@CCF) through a chemical conversion method. Faster growth of the film in the vicinity of zinc grain boundaries significantly prevents the substrate from genetic micro-corrosion that leads to catastrophic damage. The affinity of the film toward zinc facilitates a low nucleation barrier and smooth zinc deposition. Consequently, Zn@CCF enables long-term lifespan (1200 h) with low polarization ( ≈ 60 mV) at 4.4 mA cm⁻², which also maintains good capacity retention and excellent cycling stability of Zn@CCF/MnO₂ full cells. This facile and effective approach helps suppress Zn dendrite formation and brings forward the significance of surface reconstruction of the Zn metal anode for corrosion inhibition, which can be potentially applied to other metal anodes in aqueous energy storage systems.     

A Universal Superhydrophobic-Ionophilic Interfacial Strategy for Cycling Stable Aqueous Zinc Metal Electrodes under Low Current Density

A key challenge to apply aqueous zinc-metal batteries (AZMBs) as next-generation energy storage devices is to eliminate the adverse reactions of hydrogen evolution, especially in low current. Here, superhydrophobic and ionophilic artificial solid electrolyte interface (HI-SEI) on zinc anode is proposed and constructed by enhancing roughness and etching ion channels in universal polysiloxane polymer backbones. The HI-SEI exhibits superhydrophobicity with high contact angle of 151.5° and ionophilicity with low activation energy of 23.97 kJ mol⁻¹. Thus, the HI-SEI isolates Zn metal and solvent water and promotes desolvation kinetics of Zn²⁺. Besides, the HI-SEI alters the double electric layer structure to form a compact layer hardly any adsorbed solvent water, achieving a small nucleation overpotential of 5 mV and low self-corrosion current density of 0.95 µA cm⁻². Moreover, a symmetric cell with HI-SEI@Zn anode has a cycle life of >1330 h at low current of 0.1 mA cm⁻². And a full cell with HI-SEI@Zn anode and NaV₃O₈-1.5H₂O cathode provides long cycle life and low capacity degradation (180 mAh g⁻¹ after 1100 cycles). Hopefully, SEI designs based on such a strategy will be able to improve the low-current cycling performance of the next-generation AZMBs.     

Engineering Wavy‐Nanostructured Anode Interphases with Fast Ion Transfer Kinetics: Toward Practical Li‐Metal Full Batteries

Fast Li‐metal depletion and severe anode pulverization are the most critical obstacles for the energy‐dense Li‐metal full batteries using thin Li‐metal anodes (<50 µm). Here, a wavy‐nanostructured solid electrolyte interphase (SEI) with fast ion transfer kinetics is reported, which can promote high‐efficiency Li‐metal plating/stripping (>98% at 4 mAh cm^?2) in conventional carbonate electrolyte. Cryogenic transmission electron microscopy (cryo‐TEM) further reveals the fundamental relationship between wavy‐nanostructured SEI, function, and the electrochemical performance. The wavy SEI with greatly decreased surface diffusion resistance can realize grain coarsening of Li‐metal deposition and exhaustive dissolution of active Li‐metal during the stripping process, which can effectively alleviate “dead Li” accumulation and anode pulverization problems in practical full cells. Under highly challenging conditions (45 µm Li‐metal anodes, 4.3 mAh cm^?2 high capacity LiNi_0.8Mn_0.1Co_0.1O₂ cathodes), full cells exhibit significantly improved cycling lifespan (170 cycles; 20 cycles for control cells) via the application of wavy SEI.     

Engineering Polymer Glue towards 90% Zinc Utilization for 1000 Hours to Make High-Performance Zn-Ion Batteries

Zinc (Zn) metal is considered the promising anode for “post-lithium” energy storage due to its high volumetric capacity, low redox potential, abundant reserve, and low cost. However, extravagant Zn is required in present Zn batteries, featuring low Zn utilization rate and device-scale energy/power densities far below theoretical values. The limited reversibility of Zn metal is attributed to the spontaneous parasitic reactions of Zn with aqueous electrolytes, that is, corrosion with water, passive by-product formation, and dendrite growth. Here, a new ion-selective polymer glue coated on Zn anode is designed, isolating the Zn anode from the electrolyte by blocking water diffusion while allowing rapid Zn²⁺ ion migration and facilitating uniform electrodeposition. Hence, a record-high Zn utilization of 90% is realized for 1000 h at high current densities, in sharp contrast to much poorer cyclability (usually < 200 h) at lower Zn utilization (50–85%) reported to date. When matched with the vanadium-based cathode, the resulting Zn-ion battery exhibited an ultrahigh device-scale energy density of 228 Wh kg⁻¹, comparable to commercial lithium-ion batteries.     

Elastic Interfacial Layer Enabled the High-Temperature Performance of Lithium-Ion Batteries via Utilization of Synthetic Fluorosulfate Additive

The key to producing high-energy Li-ion cells is ensuring the interfacial stability of Si-containing anodes and Ni-rich cathodes. Herein, 4-(allyloxy)phenyl fluorosulfate (APFS), a multi-functional electrolyte additive that forms a mechanical strain-adaptive solid electrolyte interphase (SEI) comprising LiF and polymeric species, and a thermally stable cathode–electrolyte interface containing S O and S F species. The radical copolymerization of vinylene carbonate (VC) with APFS via electrochemical initiation creates a spatially deformable polymeric SEI on the SiG-C (30 wt.% graphite + 70 wt.% SiC composite) anode, with large volume changes during cycling. Moreover, the APFS-promoted interfacial layers reduce Ni dissolution and deposition. Furthermore, APFS deactivates the Lewis acid PF₅, thereby inhibiting hydrolyses that produce unwanted HF. These results indicate that the combined use of VC with APFS allows capacity retentions of 72.5% with a high capacity of 143.5 mAh g⁻¹ in SiG-C/LiNi_0.8Co_0.1Mn_0.1O₂ full cells after 300 cycles at 45 °C.     

Dynamic Ion Sieve as the Buffer Layer for Regulating Li+ Flow in Lithium Metal Batteries

How to realize uniform Li⁺ flow is the key to achieve even Li deposition for lithium metal batteries (LMBs). In this study, a concept of dynamic ion sieve is proposed to design the buffer layer nearby Li anode surface to regulate Li⁺ spatial arrangement by introducing tributylmethylphosphonium bis(trifluoromethanesulfonyl)imide (TMPB) into the carbonate electrolyte. The buffer layer induced by TMP⁺ can adjust the velocity of arriving solvated Li⁺ that gives solvated Li⁺ sufficient time to redistribute and accumulate on Li anode surface, resulting in a uniform and higher concentrated Li⁺ flow. Besides, TFSI⁻ can participate in the generation of inorganic component-rich solid electrolyte interphase (SEI) with Li₃N, which can facilitate the Li⁺ conductivity of SEI. Consequently, the stable and uniform Li deposition can be obtained, achieving the excellent cycling performance up to 1000 h at 0.5 mA cm⁻² in the Li||Li symmetric cell. Besides, the Li||NCM622 full cell also possesses excellent cycling stability with a high-capacity retention rate of 66.7% after 300 cycles.     

Catalytically Induced Robust Inorganic-Rich Cathode Electrolyte Interphase for 4.5 V Li||NCM622 Batteries

Tailoring inorganic components of cathode electrolyte interphase (CEI) and solid electrolyte interphase (SEI) is critical to improving the cycling performance of lithium metal batteries. However, it is challenging due to complicated electrolyte reactions on cathode/anode surfaces. Herein, the species and inorganic component content of the CEI/SEI is enriched with an objectively gradient distribution through employing pentafluorophenyl 4-nitrobenzenesulfonate (PFBNBS) as electrolyte additive guided by engineering bond order with functional groups. In addition, a catalytic effect of LiNi_0.6Mn_0.2Co_0.2O₂ (NCM622) cathode is proposed on the decomposition of PFBNBS. PFBNBS with lower highest occupied molecular orbital can be preferentially oxidized on the NCM622 surface with the help of the catalytic effect to induce an inorganic-rich CEI for superior electrochemical performance at high voltage. Moreover, PFBNBS can be reduced on the Li surface due to its lower lowest unoccupied molecular orbital , increasing inorganic moieties in SEI for inhibiting Li dendrite generation. Thus, 4.5 V Li||NCM622 batteries with such electrolyte can retain 70.4% of initial capacity after 500 cycles at 0.2 C, which is attributed to the protective effect of the excellent CEI on NCM622 and the inhibitory effect of its derived CEI/SEI on continuous electrolyte decomposition.     

Cu-Modified Ti3C2Cl2 MXene with Zincophilic and Hydrophobic Characteristics as a Protective Coating for Highly Stable Zn Anode

Zn anode is a promising candidate for aqueous batteries, but suffers from the dendrite growth and side reaction issues, leading to short cycling life and unsatisfactory reversibility. Herein, a Cu-modified Ti₃C₂Cl₂ MXene (Cu-MXene) with high zincophilic and hydrophobic property is prepared with a one-step molten salt etching method. Serving as a protective coating on Zn anode, the Cu-MXene can provide massive nucleation sites and uniformize the charge distribution, leading to homogenous Zn deposition. Moreover, the hydrophobic coating can prevent the Zn anode from the aqueous electrolyte, beneficial for suppressing the side reactions such as hydrogen evolution reaction and corrosion. Therefore, the stable and reversible Zn plating/stripping is achieved for the Zn anode coated by the Cu-MXene, which delivers an extended cycling life of over 1000 h with a low polarization within 120 mV at 10 mA cm⁻², and a high coulombic efficiency of over 99.6% for 1100 cycles, indicating excellent stability and reversibility of Zn stripping/plating. The practical full cell coupled with NaV₃O₈·1.5H₂O cathode also displays stable performance for 1000 cycles. The proposed Cu-MXene coating reveals a promising prospect for designing highly stable Zn anode, which can also be extended to other energy storage systems based on metal anodes.     

N-Rich Solid Electrolyte Interface Constructed In Situ Via a Binder Strategy for Highly Stable Silicon Anode

Silicon (Si) is regarded as a promising anode material for high-energy-density lithium-ion batteries due to its high specific capacity (4200 mAh g⁻¹) and low potential (0.3 V vs Li⁺/Li). However, the large volume change (over 300%) of Si during the lithiation/delithiation process leads to severe pulverization, electrode structure destruction, and finally capacity fading, which slows down its step to practical application. Herein, a poly(vinylamine) (PVAm) binder containing amino ( NH₂) and amide ( NH CHO) is proposed to improve the stability of Si anodes from particle to electrode structure. The N-containing functional groups show strong interaction with the Si particles and form a uniform and thin layer on the surface, which would decompose and form an N-rich inorganic solid electrolyte interphase (SEI) layer during discharging. The high mechanical stability N-rich SEI helps relieve the pulverization of Si particles through stress dissipation, maintains electrode structural stability, and reduces the loss of active materials. Thus, the Si anode with PVAm binder exhibits high capacity of ≈2000 mAh g⁻¹ after 200 cycles, which is much higher than that of using Poly(vinylidene fluoride) (PVDF) binder (66 mAh g⁻¹) and Poly(vinyl alcohol) PVA binder (820 mAh g⁻¹). This facile and practical strategy provides a new perspective for the application of Si anodes in advanced batteries.     

Solvent-Free Electrolyte for High-Temperature Rechargeable Lithium Metal Batteries

The formation of lithiophobic inorganic solid electrolyte interphase (SEI) on Li anode and cathode electrolyte interphase (CEI) on the cathode is beneficial for high-voltage Li metal batteries. However, in most liquid electrolytes, the decomposition of organic solvents inevitably forms organic components in the SEI and CEI. In addition, organic solvents often pose substantial safety risks due to their high volatility and flammability. Herein, an organic-solvent-free eutectic electrolyte based on low-melting alkali perfluorinated-sulfonimide salts is reported. The exclusive anion reduction on Li anode surface results in an inorganic, LiF-rich SEI with high capability to suppress Li dendrite, as evidenced by the high Li plating/stripping CE of 99.4% at 0.5  mA cm⁻² and 1.0 mAh cm⁻², and 200-cycle lifespan of full LiNi_0.8Co_0.15Al_0.05O₂ (2.0 mAh cm⁻²) || Li (20 µm) cells at 80 °C. The proposed eutectic electrolyte is promising for ultrasafe and high-energy Li metal batteries.