Solid Electrolyte Interface Layer Research Articles

Scalable Synthesis of SiOx-TiON Composite As an Ultrastable Anode for Li-Ion Half/Full Batteries.

Among various anode materials, SiOx is regarded as the next generation of promising anode due to its advantages of high theoretical capacity with 2680 mA h g-1, low lithium voltage platform, and rich natural resources. However, the pure SiOx-based materials have slow lithium storage kinetics attributed to their low electron/ion conductive properties and the large volume change during lithiation/delithiation, restricting their practical application. Optimizing the SiOx material structures and the fabricating methods to mitigate these fatal defects and adapt to the market demand for energy density is critical. Hence, SiOx material with TiO1-xNx phase modification has been prepared by simple, low-cost, and scalable ball milling and then combined with nitridation. Consequently, based on the TiO1-xNx modified layer, which boosts high ionic/electronic conductivity, chemical stability, and excellent mechanical properties, the SiOx@TON-10 electrode shows highly stable lithium-ion storage performance for lithium-ion half/full batteries due to a stable solid-electrolyte interface layer, fast Li+ transport channel, and alleviative volumetric expansion, further verifying its practical feasibility and universal applicability.

Electrolyte regulation achieving MoS2/C nanofiber for stable potassium-ion storage

Due to the pronounced expansion exhibited by sulfides in K-ion batteries (KIBs), achieving both high capacity and extended cycle life remains a formidable challenge. In our study, we utilized electrospinning to craft a self-standing MoS2/C electrode, and the incorporation of one-dimensional carbon was identified as a key factor significantly boosting its electronic conductivity. Addressing stability concerns, we meticulously regulated the salt concentration in ether solvents, revealing that the self-standing MoS2/C electrode exhibited outstanding electrochemical performance at a high-concentration electrolyte. After optimization, the MoS2/C electrode in 5 M ether electrolyte presents a capacity of 315 mA h g−1 after 50 cycles at 50 mA g−1. Impressively, even at 1 A g−1, the MoS2/C electrode still sustained a capacity of 200 mA h g−1 after 5000 cycles, exhibiting excellent electrochemical stability. According to our findings, decomposition occurs when the electrode material comes into contact with the electrolyte, resulting in the formation of a solid electrolyte interface (SEI) layer. In high-concentration electrolytes, a competitive mechanism between anions and ether solvent molecules takes place, with a tendency for preferential decomposition of highly concentrated anions. This behavior triggers the formation of a high-quality KF-rich SEI layer on the electrode interface, further suppressing the decomposition of subsequent electrolytes, which significantly improves the KIB’s electrochemical performance. We believe that this discovery will provide new insights for the development of high-performance KIBs.

Reconstructing Solvation Structure by Steric Hindrance‐Coordination Push‐Pull of Dipolymer‐H2O‐Zn2+ toward Long‐life Aqueous Zinc‐Metal Batteries

Aqueous zinc‐metal batteries are prospective energy storge devices due to their intrinsically high safety and cost effectiveness. Yet, uneven deposition of zinc ions in electrochemical reduction and side reactions at the anode interface significantly hinder their development and application. Here, we propose a solvation‐interface attenuation strategy enabled by a frustrated tertiary amine amphiphilic dipolymer electrolyte additive. The configuration of superhydrophilic segments with covalently bonded lipophilic spacers enables coupled steric hindrance/coordination, which establishes a balanced push‐pull dynamic of dipolymer‐H2O‐Zn2+. Such interplay reconstructs the solvation structure of Zn2+ and allows the formation of a stable dipolymer‐inorganic hybrid solid electrolyte interface (SEI) layer. This SEI layer effectively shields the zinc‐metal anode from water and anions, significantly reducing side reactions. In addition, the dipolymer adsorbed at the zinc‐metal anode interface regulates the interfacial electrochemical reduction kinetics and ensures uniform zinc deposition. As a result, the Zn‐Zn symmetric cells with dipolymer‐containing electrolyte exhibit remarkable cycling stability exceeding 5800 h (242 days). The Zn‐NVO batteries and Zn‐AC hybrid ion supercapacitors also deliver stable cycling for up to 1440 h (60 days) with high‐capacity retention over 80%. This research demonstrates the potential to facilitate the development and commercialization of zinc‐based energy storage devices.

Reconstructing Solvation Structure by Steric Hindrance-Coordination Push-Pull of Dipolymer-H2O-Zn2+ toward Long-life Aqueous Zinc-Metal Batteries.

Aqueous zinc-metal batteries are prospective energy storge devices due to their intrinsically high safety and cost effectiveness. Yet, uneven deposition of zinc ions in electrochemical reduction and side reactions at the anode interface significantly hinder their development and application. Here, we propose a solvation-interface attenuation strategy enabled by a frustrated tertiary amine amphiphilic dipolymer electrolyte additive. The configuration of superhydrophilic segments with covalently bonded lipophilic spacers enables coupled steric hindrance/coordination, which establishes a balanced push-pull dynamic of dipolymer-H2O-Zn2+. Such interplay reconstructs the solvation structure of Zn2+ and allows the formation of a stable dipolymer-inorganic hybrid solid electrolyte interface (SEI) layer. This SEI layer effectively shields the zinc-metal anode from water and anions, significantly reducing side reactions. In addition, the dipolymer adsorbed at the zinc-metal anode interface regulates the interfacial electrochemical reduction kinetics and ensures uniform zinc deposition. As a result, the Zn-Zn symmetric cells with dipolymer-containing electrolyte exhibit remarkable cycling stability exceeding 5800 h (242 days). The Zn-NVO batteries and Zn-AC hybrid ion supercapacitors also deliver stable cycling for up to 1440 h (60 days) with high-capacity retention over 80%. This research demonstrates the potential to facilitate the development and commercialization of zinc-based energy storage devices.

Multifunctional Additives to Realize Dendrite‐Free Lithium Deposition in Carbonate Electrolytes toward Low‐Temperature Li Metal Batteries

AbstractLi metal is recognized as one of the most promising anode candidates for next‐generation high specific energy batteries. However, the fragile solid electrolyte interface (SEI) and heterogeneous Li plating/stripping in carbonate electrolyte severely encumber its practical application. Here, the heptafluorobutyramide (HFT) and lithium nitrate (LiNO3) are proposed to synergistically construct a robust SEI layer with excellent Li+ transport kinetics. The HFT can promote the dissolution of LiNO3 in carbonate electrolyte due to the strong cooperation. The results of theoretical calculations, in situ Raman and X‐ray photoelectron spectroscopy with deep Ar‐ion etching demonstrate that HFT and NO3− will be preferentially reduced to a Li3N/LiF‐rich composite structure on the surface of Li metal. Particularly, after the addition of additives, the first solvent shell is converted from solvent‐dominated to anion‐dominated structure, and thus a significantly lower Li‐ion desolvation barrier is presented. Consequently, the Coulombic efficiency (CE) of Li||Cu half cells using the designed carbonate electrolyte can reach 97.1%. The full cells matched with LiFePO4 and LiNi0.8Co0.1Mn0.1O2 (NCM 811) can deliver high‐capacity retention over 100% at −20°C. This work provides an effective strategy for the regulation of solvation structure and the construction of high‐performance Li metal batteries.

Behavior of NO3−-Based Electrolyte Additive in Lithium Metal Batteries

While lithium metal is highly desired as a next-generation battery material due to its theoretically highest capacity and lowest electrode potential, its practical application has been impeded by stability issues such as dendrite formation and short cycle life. Ongoing research aims to enhance the stability of lithium metal batteries for commercialization. Among the studies, research on N-based electrolyte additives, which can stabilize the solid electrolyte interface (SEI) layer and provide stability to the lithium metal surface, holds great promise. The NO3− anion in the N-based electrolyte additive causes the SEI layer on the lithium metal surface to contain compounds such as Li3N and Li2O, which not only facilitates the conduction of Li+ ions in the SEI layer but also increases its mechanical strength. However, due to challenges with the solubility of N-based electrolyte additives in carbonate-based electrolytes, extensive research has been conducted on electrolytes based on ethers. Nonetheless, the low oxidative stability of ether-based electrolytes hinders their practical application. Hence, a strategy is needed to incorporate N-based electrolyte additives into carbonate-based electrolytes. In this review, we address the challenges of lithium metal batteries and propose practical approaches for the application and development of N-based electrolyte additives.

Silicon Solid State Battery: The Solid‐State Compatibility, Particle Size, and Carbon Compositing for High Energy Density

AbstractSolid‐state battery research has gained significant attention due to their inherent safety and high energy density. Silicon anodes have been promoted for their advantageous characteristics, including high volumetric capacity, low lithiation potential, high theoretical and specific gravimetric capacity, and the absence of lethal dendritic growth. Addressing concerns such as low conductivity, pulverization, fracture, dense solid electrolyte interface layer, and low coulombic efficiency has substantially improved the use of silicon electrodes in solid‐state batteries. Researchers have explored carbon additions, solid electrolyte suitability for Si anodes, pressure optimization, and particle size effects (nano/micro) to enhance energy density. Recent studies have investigated the conductivity mechanism, stack pressure, and anode‐solid electrolyte compatibility to improve energy density. Micro‐ and nano‐sized silicon have attracted attention in carbon‐based composites due to their exceptional conductivity, uniform distribution, efficient electron migration, and diffusion channels. The development of solid‐state batteries with high energy density, safety, and extended lifespan has been a major focus. This review sheds light on significant insights and strategic approaches for researchers working on solid‐state silicon‐based systems to overcome existing challenges.

Core‐Shell Architectured Sulfur Coated α‐Fe2O3 Nano‐Sheet Anode for Li‐Ion Battery with Insitu Active Solid Electrolyte Interfacial Layer and Li‐Sulfur Energy Storage Systems

AbstractA versatile approach is achieved through the surface coating of sulfur on α‐Fe2O3 nanosheet by microwave treatment that inherently supports the formation of self‐induced active solid electrolyte interface (SEI) layer which effectively protects the electrode surface and enhances the cyclic stability of lithium‐ion battery. The present findings on a sulfur‐coated α‐Fe2O3@S‐2 core‐shell structured anode demonstrates an initial specific capacity of 1194 mAh g−1 at a 0.1 C rate, and an average discharge capacity of 518 mAh g−1 over 20 cycles. Sulfur coating proves the incredible development of an active SEI layer that prevents electrolyte decomposition and the electrode persuades with stable capacity, fast rate capability and retains excellent coulombic efficiency for 500 cycles in LIB. GITT measurements exhibit superior Li+ ion diffusion coefficient 2.87×10−10 cm2 s−1 at 80 % SOC for the α‐Fe2O3@S‐2 electrode. The in‐depth ex‐situ evaluations uncovered a fascinating self‐assembled active Li2SO4 electrode‐electrolyte interface formation in the sulfur‐coated α‐Fe2O3 electrode that contributes interfacial kinetics. The sulfur coated α‐Fe2O3 electrode exhibits an exceptional high‐rate performance and coulombic efficiency even in lithium‐sulfur battery. This research overthrows sulfur‘s significance in forming an active interfacial bridging SEI layer that facilitates lithium‐ion kinetics across the interface and alleviates undesirable SEI development.

Biopolymer Binders for Low‐Temperature Operation of TiNb2O7 Anode in Li‐Ion Batteries

The widespread use of lithium‐ion batteries underlines the criticality of a more sustainable cell fabrication. Here, three biopolymers gelatin, pectin, and deoxyribonucleic acid (DNA) are investigated as binders for the TiNb2O7 anode material in Li cells in a temperature range between 0 and 60 ºC and compared to conventional binder polyvinylidene fluoride (PVDF). The use of biopolymers is motivated by their own environmental friendliness and the possibility to implement an aqueous electrode processing. A specific charge capacity of at least 200 mAh g−1 is found for all binders at 0 °C when testing the cycling performance of TiNb2O7 at 77.5 mA g−1 (1C rate). However, low‐rate cycling at 60 °C shows decreasing capacity for all biopolymers due to the swelling effect and continuous contact loss to the current collector, what also reflects in lowering the overall Li‐diffusion coefficient. This effect becomes less pronounced at 0 °C and high current densities, making biopolymers competitive with commercial PVDF. The electrodes with DNA binder demonstrate overall the most stable performance, arising from the biopolymer intactness and a thin solid–electrolyte interface layer. At 0 °C, the electrode with DNA provides 150 mAh g−1 at 775 mA g−1 for at least 500 discharge–charge cycles.

Non-destructive chemical prelithiation of VO2(B) anodes constructing a multifunctional interphase layer for advanced Li-Ion batteries

VO2(B) stands as a promising anode material, comparable to the disordered rock-salt phase Li3+xV2O5, owning to its ease of preparation, suitable redox potential, and remarkable rate capability. However, the practical application of VO2(B) anodes faces substantial limitations due to its low initial coulombic efficiency (ICE) and instability of solid electrolyte interface (SEI) layer during cycling. In this study, we introduce a highly efficient, controllable, and non-destructive chemical prelithiation method utilizing a reductive Li-arene reagent, formed by dissolving Li-metal to THF solutions containing biphenyl derivatives. This method enables the VO2(B) anode to achieve an ICE of nearly 100 %. The investigation on the chemical composition and mechanical properties of SEI layers reveals that the prelithiated VO2(B) electrode contains a more favorable LiF component, fewer adverse byproducts, and exhibits a thinner thickness with high structural strength. Kinetic analysis demonstrates that the prelithiation treatment accelerates the diffusion of lithium ions, reduces interfacial reaction resistances, and maintains interface stability during cycling. To demonstrate the practical application, we assemble a well-designed Prelithiation VO2(B)||NCM811 full cell, achieving an enhancement in the energy density of at least 20 %. This work underscores the potential of prelithiated VO2(B) electrodes for developing lithium-ion batteries (LIBs) with high-safety and high-energy/power density.

Synergistically enhanced LiF–rich protective layer for highly stable silicon anodes

Silicon (Si) is considered as one of the most promising anode materials with an extremely high specific capacity (3579 mAh/g), which is beyond the limit of conventional graphite anodes in lithium (Li) ion batteries (LIBs). However, large volume changes during the lithiation/delithiation process and formation of an unstable solid electrolyte interface (SEI) layer hinder the practical application of Si anodes. To address these issues, constructing a stable protective layer at the interface between anode and electrolyte is a desirable strategy. In this study, a LiF-rich SEI inducing protective layer (LPL) comprising aluminum fluoride (AlF3) and poly(acrylic acid) (PAA) is introduced onto Si anode to construct a stable LiF–rich SEI layer and mitigate the volume changes of the Si anodes during cycling. Owing to the synergetic effects of AlF3 and PAA, a LiF-rich SEI layer with robust physicochemical properties is uniformly formed on the Si anode. As a result, the LPL coated Si (LPL@Si) anodes exhibit outstanding electrochemical properties in Li metal cell tests. In addition, a full-cell prepared with the LPL@Si anode and LiNi0.8Co0.1Mn0.1O2 as a cathode exhibits an excellent cycling performance and mitigated volume changes, demonstrating the potential of this strategy to protect the Si anodes for the development of high-energy–density LIBs.

Ni‐Single Atoms Modification Enabled Kinetics Enhanced and Ultra‐Stable Hard Carbon Anode for Sodium‐Ion Batteries

AbstractHard carbon with randomly oriented interlayers is the most promising candidate for the anode of commercial sodium‐ion batteries (SIBs). Nevertheless, its sluggish sodium storage kinetics and unsatisfactory cycling stability are bottlenecks to its implementation. Herein, a metal‐single atom modification strategy is proposed to construct a Ni‐single atoms modified N, P co‐doped hard carbon (Ni‐NPC) with a Ni content of ≈5.65 wt%. As an anode for SIBs, Ni‐NPC exhibits far superior initial Coulombic efficiency, reversible specific capacity, rate capability, and cycling stability to N, P co‐doped hard carbon. Combining in situ EIS and ex‐situ XPS,this study reveals that Ni‐single atoms modulate the composition of the solid electrolyte interface layer, thereby improving the cycling stability of Ni‐NPC. Theoretical calculation and kinetics analysis suggest that Ni‐single atoms are the promoters of the diffusion of Na+. Furthermore, with the aid of systematic in situ characterizations, the structural evolution of Ni‐NPC at different sodium storage stages is identified. This work proposes a potential strategy for simultaneously improving the sodium storage kinetics and cycling stability of hard carbon anodes, and elucidates the improvement mechanism of this strategy.

Dual-Parasitic Effect Enables Highly Reversible Zn Metal Anode for Ultralong 25,000 Cycles Aqueous Zinc-Ion Batteries.

The use of electrolyte additives is an efficient approach to mitigating undesirable side reactions and dendrites. However, the existing electrolyte additives do not effectively regulate both the chaotic diffusion of Zn2+ and the decomposition of H2O simultaneously. Herein, a dual-parasitic method is introduced to address the aforementioned issues by incorporating 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIm]OTf) as cosolvent into the Zn(OTf)2 electrolyte. Specifically, the OTf- anion is parasitic in the solvent sheath of Zn2+ to decrease the number of active H2O. Additionally, the EMIm+ cation can construct an electrostatic shield layer and a hybrid organic/inorganic solid electrolyte interface layer to optimize the deposition behavior of Zn2+. This results in a Zn anode with a reversible cycle life of 3000 h, the longest cycle life of full cells (25,000 cycles), and an extremely high initial capacity (4.5 mA h cm-2), providing a promising electrolyte solution for practical applications of rechargeable aqueous zinc-ion batteries.

Triiodide Anion as a Magnesium-ion Transporter for Low Overpotential Battery Cycling in Iodine-Containing Mg(TFSI)2 Electrolyte.

Magnesium iodide (MgI2) solid-electrolyte interface (SEI) layers have previously been shown to protect Mg metal anodes from passivation through products formed during Mg(TFSI)2 electrolyte decomposition (TSFI = trifluorosulfonimide). MgI2 formed in situ from small quantities of I2 added to the electrolyte shows a drastic decrease in the overpotential for magnesium deposition and stripping. In this work, a MgI2 SEI layer was created in an ex situ fashion and then the electrochemical characteristics of this MgI2 SEI layer were probed both alone and with small quantities of I2 or Bu4NI3 additives to identify the electroactive species. Chronopotentiometry (CP) and cyclic voltammetry (CV) show that the MgI2 SEI alone is insufficient for low overpotential magnesium cycling. I(3d) XPS data show that I3- is formed within the SEI layer, which can serve as the electroactive species when ligated with Mg2+ for low overpotential (<50 mV at 0.1 mA cm-2 current density) cycling. Moreover, Raman shifts at 110 and 140 cm-1 are consistent with I3- formation, and these signatures are observed before and after CP experiments. The Mg0 deposition curves in the CV with additives are consistent with diffusive species. Finally, electrochemical impedance spectroscopy (EIS) shows that there is a large decrease in the charge-transfer resistance within the SEI when either I2 or Bu4NI3 additives are used, which supports a solvating effect that facilitates magnesium deposition and stripping.

Imidazole-2-carboxaldehyde additive participation in construction of SEI enabling ultra-stable Zn anode

Poor stability caused by side reactions such as corrosion, Zn dendrite and hydrogen evolution are crucial factors hindering commercial application in queous zinc ion energy storage systems. This article offers a strategy, zinc-rich Solid electrolyte interface (SEI) layer with polar groups by imidazole-2-carboxaldehyde (2-ICA) electrolyte additive, which helps form stable electrode/electrolyte interface and rapid Zn2+ transfer interface with low resistance. Firstly, the chelation with Zn2+ of 2-ICA and its zincophilic capability enable the rapid formation of the SEI layer and result in more sites for initial nucleation, which then guides the uniform Zn2+ deposition. Additionally, the introduced SEI with polar groups accelerates the de-solvation kinetics of Zn2+ and the Zn2+ transfer ability in electrode/electrolyte interface, which enable high-rate charge and discharge. Therefore, the symmetric battery based on 2-ICA electrolyte exhibits excellent cycling stability at 20 mA cm−2 (cycling up to 800 h). At the same time, assembled Zn//Cu also has a high average Coulombic efficiency (99.2 %). The zinc-ion hybrid capacitors (ZICs) assembled based on this electrolyte also exhibit outstanding electrochemical properties. This work offers a simple and novel way to realize high performance and great safety zinc-based energy storage devices.

Regulated Hydrated Eutectic Electrolyte Enhancing Interfacial Chemical Stability for Highly Reversible Aqueous Aluminum‐Ion Battery with a Wide Temperature Range of −20 to 60 °C

AbstractThe development of aqueous aluminum‐ion batteries (AAIBs) is impeded by pronounced side reactions and hydrogen evolution reaction (HER). Here, an eutectic electrolyte named HEE30 (with an optimal molar ratio of 1:8:1:30 for Al(OTf)3, glycerol (Gly), sodium beta‐glycerophosphate pentahydrate (SG), and H2O) to significantly enhance the reversibility of AAIBs across a wide temperature range from −20 to 60 °C is designed. The combination of molecular dynamics simulations and operando synchrotron Fourier‐transform infrared spectroscopy reveals that the unique eutectic network significantly enhances the hydrogen bonding between Gly and H2O, reduces the solvation interaction of Al3+ with active H2O, thereby lowering the freezing point, extending electrochemical windows and suppressing HER. The X‐ray photoelectron spectroscopy (XPS) and X‐ray diffraction (XRD) tests demonstrate that HEE30 is capable of forming a solid electrolyte interface layer consisting of organic and inorganic components, which effectively inhibits corrosion. Additionally, operando synchrotron XRD and ex situ XPS are employed to investigate the changes in lattice peak width and position of the Prussian white cathode, as well as the reversible storage mechanism during cycling This quantitative design offer immediate advantages for the rational development of low‐cost and safe energy storage batteries, specifically tailored for wide‐temperature operation and durable cycling.

Boron-doped three-dimensional porous carbon framework/carbon shell encapsulated silicon composites for high-performance lithium-ion battery anodes

Deleterious volumetric expansion and poor electrical conductivity seriously hinder the application of Si-based anode materials in lithium-ion batteries (LIBs). Herein, boron-doped three-dimensional (3D) porous carbon framework/carbon shell encapsulated silicon (B-3DCF/Si@C) hybrid composites are successfully prepared by two coating and thermal treatment processes. The presence of 3D porous carbon skeleton and carbon shell effectively improves the mechanical properties of the B-3DCF/Si@C electrode during the cycling process, ensures the stability of the electrical contacts of the silicon particles and stabilizes the solid electrolyte interface (SEI) layer, thus enhancing the electronic conductivity and ion migration efficiency of the anode. The developed B-3DCF/Si@C anode has a high reversible capacity, excellent cycling stability and outstanding rate performance. A reversible capacity of 1288.5 mAh/g is maintained after 600 cycles at a current density of 400 mA g−1. The improved electrochemical performance is demonstrated in a full cell using a LiFePO4-based cathode. This study presents a novel approach that not only mitigates the large volume expansion effects in LIB anode materials, but also provides a reference model for the preparation of porous composites with various functionalities.

Saccharin Sodium Coupling Fluorinated Solvent Enabled Stable Interface for High-Voltage Li-Metal Batteries.

Optimizing the electrode/electrolyte interface structure is the key to realizing high-voltage Li-metal batteries (LMBs). Herein, a functional electrolyte is introduced to synergetically regulate the interface layer structures on the high-voltage cathode and the Li-metal anode. Saccharin sodium (NaSH) as a multifunctional electrolyte additive is employed in fluorinated solvent-based electrolyte (FBE) for robust interphase layer construction. On the one hand, combining the results of ex-situ techniques and in-situ electrochemical dissipative quartz crystal microbalance (EQCM-D) technique, it can be seen that the solid electrolyte interface (SEI) layer constructed by NaSH-coupled fluoroethylene carbonate (FEC) on Li-metal anode significantly inhibits the growth of lithium dendrites and improves the cyclic stability of the anode. On the other hand, the experimental results also confirm that the cathode-electrolyte interface (CEI) layer induced by NaSH-coupled FEC effectively protects the active materials of LiCoO2 and improves their structural stability under high-voltage cycling, thus avoiding the material rupture. Moreover, theoretical calculation results show that the addition of NaSH alters the desolvation behavior of Li+ and enhances the transport kinetics of Li+ at the electrode/electrolyte interface. In this contribution, the LiCoO2 ǁLi full cell containing FBE+NaSH results in a high capacity retention of 80% after 530 cycles with a coulombic efficiency of 99.8%.

In Situ Plasma Polymerization of Self-Stabilized Polythiophene Enables Dendrite-Free Lithium Metal Anodes with Ultra-Long Cycle Life.

Constructing a flexible and chemically stable multifunctional layer for the lithium (Li) metal anodes is a highly effective approach to improve the uneven deposition of Li+ and suppress the dendrite growth. Herein, an organic protecting layer of polythiophene is in situ polymerized on the Li metal via plasma polymerization. Compared with the chemically polymerized thiophene (C-PTh), the plasma polymerized thiophene layer (P-PTh), with a higher Young's modulus of 8.1GPa, shows strong structural stability due to the chemical binding of the polythiophene and Li. Moreover, the nucleophilic C─S bond of polythiophene facilitates the decomposition of Li salts in the electrolytes, promoting the formation of LiF-rich solid electrolyte interface (SEI) layers. The synergetic effect of the rigid LiF as well as the flexible PTh-Li can effectively regulate the uniform Li deposition and suppress the growth of Li dendrites during the repeated stripping-plating, enabling the Li anodes with long-cycling lifespan over 8000h (1mAcm-2 , 1 mAhcm-2) and 2500h (10mAcm-2 , 10 mAhcm-2 ). Since the plasma polymerization is facile (5-20min) and environmentally friendly (solvent-free), this work offers a novel and promising strategy for the construction of the forthcoming generation of high-energy-density batteries.

Stabilizing poly(vinylidene fluoride) solid-state electrolytes/lithium metal interface by constructing an ultrathin interface layer to inhibit the electron transfer

Residual N, N-dimethylformamide (DMF) enhances the conductivity of poly(vinylidene fluoride) (PVDF) solid-state polymer electrolytes (SPEs), but adversely impacts the SPEs/Li interface through electron transfer between DMF and Li. Herein, we developed a novel LiOH and LiNH2 (LON) artificial solid electrolyte interface (SEI) layer with limited electronic conductivity to block such electron transfer. Unlike conventional SEI, which are unsuitable for integration with SPEs since their high thickness (1–30 μm) results in high interfacial resistance, the LON layer is ultrathin (∼30 nm), and more importantly, it facilitates the separation of Li ions from Li-DMF bound ions during Li plating, contributing to a notable reduction in interfacial impedance. As a result, the LON protected Li (Li@LON)-based symmetrical cell exhibits an ultra-long cycle life of 2100 h and survives even under 0.6 mAh cm−2 at 25 °C, in stark contrast to the Bare Li-based symmetrical cell, which only maintains stable cycles for 806 h at 0.2 mAh cm−2. Furthermore, the Li@LON//LiNi0.8Co0.1Mn0.1O2 (NCM811) cell stably cycles over 3000 times at 0.5 C and 25 °C, significantly outperforming the Li//NCM811 cell with 880 times. This work paves a novel strategy for stabilizing SPEs-Li interface by constructing an ultrathin artificial SEI with low electronic conductivity.