Enhancing Ultrafast Lithium Ion Storage of Li4Ti5O12 by Tailored TiC/C Core/Shell Skeleton Plus Nitrogen Doping

It is of great importance to reinforce electronic and ionic conductivity of Li₄Ti₅O₁₂ electrodes to achieve fast reaction kinetics and good high‐power capability. Herein, for the first time, a dual strategy of combing N‐doped Li₄Ti₅O₁₂ (N‐LTO) with highly conductive TiC/C skeleton to realize enhanced ultrafast Li ion storage is reported. Interlinked hydrothermal‐synthesized N‐LTO nanosheets are homogeneously decorated on the chemical vapor deposition (CVD) derived TiC/C nanowires forming binder‐free N‐LTO@TiC/C core–branch arrays. Positive advantages including large surface area, strong mechanical stability, and enhanced electronic/ionic conductivity are obtained in the designed integrated arrays and rooted upon synergistic TiC/C matrix and N doping. The above appealing features can effectively boost kinetic properties throughout the N‐LTO@TiC/C electrodes to realize outstanding high‐rate capability at different working temperatures (143 mAh g^?1/10 C at 25 °C and 122 mAh g^?1/50 C at 50 °C) and notable cycling stability with a capacity retention of 99.3% after 10 000 cycles at 10 C. Moreover, superior high‐rate cycling life is also demonstrated for the full cells with N‐LTO@TiC/C anode and LiFePO₄ cathode. The dual strategy may provoke wide interests in fast energy storage areas and motivate the further performance improvement of power‐type lithium ion batteries (LIBs).     

High‐Performance Solid Polymer Electrolytes Filled with Vertically Aligned 2D Materials

Solid state lithium metal batteries are the most promising next‐generation power sources owing to their high energy density and safety. Solid polymer electrolytes (SPE) have gained wide attention due to the excellent flexibility, manufacturability, lightweight, and low‐cost processing. However, fatal drawbacks of the SPE such as the insufficient ionic conductivity and Li⁺ transference number at room temperature restrict their practical application. Here vertically aligned 2D sheets are demonstrated as an advanced filler for SPE with enhanced ionic conductivity, Li⁺ transference number, mechanical modulus, and electrochemical stability, using vermiculite nanosheets as an example. The vertically aligned vermiculite sheets (VAVS), prepared by the temperature gradient freezing, provide aligned, continuous, run‐through polymer‐filler interfaces after infiltrating with polyethylene oxide (PEO)‐based SPE. As a result, ionic conductivity as high as 1.89 × 10^?4 S cm^?1 at 25 °C is achieved with Li⁺ transference number close to 0.5. Along with their enhanced mechanical strength, Li|Li symmetric cells using VAVS–CSPE are stable over 1300 h with a low overpotential. LiFePO₄ in all‐solid‐state lithium metal batteries with VAVS–CSPE could deliver a specific capacity of 167 mAh g^?1 at 0.1 C at 35 °C and 82% capacity retention after 200 cycles at 0.5 C.     

A Mixed Lithium‐Ion Conductive Li2S/Li2Se Protection Layer for Stable Lithium Metal Anode

Constructing artificial solid‐electrolyte interphase (SEI) on the surface of Li metal is an effective approach to improve ionic conductivity of surface SEI and buffer Li dendrite growth of Li metal anode. However, constructing of homogenous ideal artificial SEI is still a great challenge. Here, a mixed lithium‐ion conductive Li₂S/Li₂Se (denoted as LSSe) protection layer, fabricated by a facile and inexpensive gas–solid reaction, is employed to construct stable surface SEI with high ionic conductivity. The Li₂S/Li₂Se‐protected Li metal (denoted as LSSe@Li) exhibits a stable dendrite‐free cycling behavior over 900 h with a high lithium stripping/plating capacity of 3 mAh cm^?2 at 1.5 mA cm^?2 in the symmetrical cell. Compared to bare Li anode, full batteries paired with LiFePO₄, sulfur/carbon, and LiNi_0.6Co_0.2Mn_0.2O₂ cathodes all present better battery cycling and rate performance when LSSe@Li anode is used. Moreover, Li₂Se exhibits a lower lithium‐ion migration energy barrier in comparison with Li₂S which is proved by density functional theory calculation.     

Inserting Sn Nanoparticles into the Pores of TiO2−x–C Nanofibers by Lithiation

Tin holds promise as an anode material for lithium‐ion batteries (LIBs) because of its high theoretical capacity, but its cycle life is limited by structural degradation. Herein, a novel approach is exploited to insert Sn nanoparticles into the pores of highly stable titanium dioxide–carbon (TiO_2?x–C) nanofiber substrates that can effectively localize the postformed smaller Sn nanoparticles, thereby address the problem of structural degradation, and thus achieve improved anode performance. During first lithiation, a Li_4.4Sn alloy is inserted into the pores surrounding the initial Sn nanoparticles in TiO_2?x–C nanofibers by its large volume expansion. Thereafter, the original Sn nanoparticle with a diameter of about 150 nm cannot be recovered by the delithiation because of the surface absorption between inserted Sn nanoparticles and the TiO_2?x–C substrate, resulting in many smaller Sn nanoparticles remaining in the pores. Batteries containing these porous TiO_2?x–C–Sn nanofibers exhibit a high capacity of 957 mAh g^?1 after 200 cycles at 0.1 A g^?1 and can cycle over 10 000 times at 3 A g^?1 while retaining 82.3% of their capacity, which represents the longest cycling life of Sn‐based anodes for LIBs so far. This interesting method can provide new avenues for other high‐capacity anode material systems that suffer from significant volume expansion.     

Facile Li+ Transport in Interpenetrating O- and F-Containing Polymer Networks for Solid-State Lithium Batteries

Solid polymer electrolytes (SPEs) provide an intimate contact with electrodes and accommodate volume changes in the Li-anode, making them ideal for all-solid-state batteries (ASSBs); however, confined chain swing, poor ion-complex dissociation, and barricaded Li⁺-transport pathways limit the ionic conductivity of SPEs. This study develops an interpenetrating polymer network electrolyte (IPNE) comprising poly(ethylene oxide)- and poly(vinylidene fluoride)-based networked SPEs (O-NSPE and F-NSPE, respectively) and lithium bis(fluorosulfonyl) imide (LiFSI) to address these challenges. The  CF₂ / CF₃ segments of the F-NSPE segregate FSI⁻ to form connected Li⁺-diffusion domains, and  C O C segments of the O-NSPE dissociate the complexed ions to expedite Li⁺ transport. The synergy between O-NSPE and F-NSPE gives IPNE high ionic conductivity (≈1 mS cm⁻¹) and a high Li-transference number (≈0.7) at 30 °C. FSI⁻ aggregation prevents the formation of a space-charge zone on the Li-anode surface to enable uniform Li deposition. In Li||Li cells, the proposed IPNE exhibits an exchange current density exceeding that of liquid electrolytes (LEs). A Li|IPNE|LiFePO₄ ASSB achieves charge–discharge performance superior to that of LE-based batteries and delivers a high rate of 7 mA cm⁻². Exploiting the synergy between polymer networks to construct speedy Li⁺-transport pathways is a promising approach to the further development of SPEs.     

Core–Shell Ge@Graphene@TiO2 Nanofibers as a High‐Capacity and Cycle‐Stable Anode for Lithium and Sodium Ion Battery

Germanium is considered as a promising anode material because of its comparable lithium and sodium storage capability, but it usually exhibits poor cycling stability due to the large volume variation during lithium or sodium uptake and release processes. In this paper, germanium@graphene nanofibers are first obtained through electrospinning followed by calcination. Then atomic layer deposition is used to fabricate germanium@graphene@TiO₂ core–shell nanofibers (Ge@G@TiO₂ NFs) as anode materials for lithium and sodium ion batteries (LIBs and SIBs). Graphene and TiO₂ can double protect the germanium nanofibers in charge and discharge processes. The Ge@G@TiO₂ NFs composite as an anode material is versatile and exhibits enhanced electrochemical performance for LIBs and SIBs. The capacity of the Ge@G@TiO₂ NFs composite can be maintained at 1050 mA h g^?1 (100th cycle) and 182 mA h g^?1 (250th cycle) for LIBs and SIBs, respectively, at a current density of 100 mA g^?1, showing high capacity and good cycling stability (much better than that of Ge nanofibers or Ge@G nanofibers).     

Surface Li2CO3 Mediated Phosphorization Enables Compatible Interfaces of Composite Polymer Electrolyte for Solid-State Lithium Batteries

Composite polymer electrolytes (CPEs) are subject to interface incompatibilities due to the space charge layer of ceramic and polymer phases. The intensive dehydrofluorination of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) incorporating Li₇La₃Zr₂O₁₂ (LLZO) significantly compromises electro-chemo-mechanical properties and compatibilities with electrodes. Herein, this study addresses the challenges by precisely phosphatizing LLZO surfaces through a surface Li₂CO₃ mediated chemical reaction. The designed neutral chemical environment of LLZO surfaces ensures high air stability and effective suppression of PVDF-HFP dehydrofluorination. This greatly facilitates the uniform distribution of ceramic and polymer phases, and fast interfacial Li⁺ exchange, establishing high-throughput ion percolation pathways and distinctly enhancing ionic conductivity and transference number. Moreover, the dramatically reduced formation of dehydrofluorination products and an in situ formed interphase layer between phosphatized surface and a Li metal anode stabilize the Li/CPE and cathode/CPE interfaces, which provide a symmetric Li/Li cell and solid-state Li/LiFePO₄ and Li/LiNi_0.8Co_0.1Mn_0.1O₂ cells an exceptional cycling performance at room temperature. This study emphasizes the vital importance of achieving electro-chemo-mechanical compatibilities for CPEs and provides a new waste to wealth route.     

Tandem Design of Functional Separators for Li Metal Batteries with Long-Term Stability and High-Rate Capability

The lithium (Li) dendrite growth seriously hinders the applications of lithium metal batteries (LMBs). Numerous methods have been proposed to restrict the formation of Li dendrites by improving the Li-ion transference number (t_Li⁺) through separator modification according to Sand's time equation. However, ignoring the positive contribution of anion motion to solid electrolyte interphase (SEI) formation will result in insufficient inorganic components, which impedes practical implementation of LMBs. Herein, a “tandem” separator is constructed (ZSM-5-Poly dimethyl diallyl ammonium chloride (PDDA)/Polyethylene (PE)/SbF₃), which anchored anions and built an inorganic-rich SEI at the same time. The resulting SEI from SbF₃ (SBF) coating on side facing Li is rich in Li-Sb alloy (Li₃Sb) and LiF. Li₃Sb can significantly reduce the migration energy barrier of Li ion (Li⁺) and facilitate Li⁺ transport. Simultaneously, ZSM-5-PDDA (Z5P) coating at the other side can effectively immobilize anions and increase the t_Li⁺. Moreover, the regular pore structure is conducive to homogenizing Li⁺ flux and also capable to uniform temperature distribution, significantly improving safety. Hence, the lifespan of Li|Li and Li|Cu cells assemble with Z5P/PE/SBF separator is significantly extended. In addition, full cells with LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) and LiFePO₄ (LFP) cathodes show excellent cycle stability and superior rate performance.     

In Situ Formation of Li3P Layer Enables Fast Li+ Conduction across Li/Solid Polymer Electrolyte Interface

Solid‐state polymer electrolytes provide better flexibility and electrode contact than their ceramic counterparts, making them a worthwhile pursuit for all‐solid‐state lithium‐metal batteries. However, their large Li/solid state electrolyte interfacial resistance, small critical current density, and rapid lithium dendrite growth during cycling still limit their viability. Owing to these restrictions, all‐solid‐state cells with solid polymer electrolytes must be cycled above room‐temperature and with a small current density. These problems can be mitigated with an in situ formed artificial solid electrolyte interphase that rapidly conducts Li⁺ ions. Herein, a Li₃P layer formed in situ at the Li‐metal/solid polymer electrolyte interphase is reported that significantly reduces the electrode/electrolyte interfacial resistance. Additionally, this layer increases the wettability of the solid polymer by the metallic lithium anode, allowing for the critical current density of lithium symmetric cells to be doubled by homogenizing the current density at the interface. All‐solid‐state Li/Li symmetric cells and Li/LiFePO₄ cells with the Li₃P layer show improved cycling performance with a high current density.     

Hierarchical Co3O4 Nanofiber–Carbon Sheet Skeleton with Superior Na/Li‐Philic Property Enabling Highly Stable Alkali Metal Batteries

Uncontrollable dendritic behavior and infinite volume expansion in alkali metal anode results in the severe safety hazards and short lifespan for high‐energy batteries. Constructing a stable host with superior Na/Li‐philic properties is a prerequisite for commercialization. Here, it is demonstrated that the small Gibbs free energy change in the reaction between metal oxide (Co₃O₄, SnO₂, and CuO) and alkali metal is key for metal infusion. The as‐prepared hierarchical Co₃O₄ nanofiber–carbon sheet (CS) skeleton shows improved wettability toward molten Li/Na. The 3D carbon sheet serves as a primary framework, offering adequate lithium nucleation sites and sufficient electrolyte/electrode contact for fast charge transfer. The secondary framework of Co/Li₂O nanofibers provides physical confinement of deposited Li and further redistributes the Li⁺ flux on each carbon fiber, which is verified by COMSOL Multiphysics simulations. Due to the uniform deposition behavior and near‐zero volume change, modified symmetrical Li/Li cells can operate under an ultrahigh current density of 20 mA cm^?2 for more than 120 cycles. When paired with LiFePO₄ cathodes, the Li/Co–CS cell shows low polarization and 88.4% capacity retention after 200 cycles under 2 C. Convincing improvement can also be observed in Na/Co–CS symmetrical cells applying NaClO₄‐based electrolyte. These results illustrate a significant improvement in developing safe and stable alkali metal batteries.     

Dendrite‐Free Lithium Plating Induced by In Situ Transferring Protection Layer from Separator

Lithium (Li) metal anodes are regarded as a promising pathway to meet the rapidly growing requirements on high energy density cells, owing to their highest gravimetric capacity (3840 mAh g^?1) and their lowest redox potential. The application of Li metal anodes, however, is still hindered by undesired dendrites formation and endless consumption of liquid electrolyte due to a continuous reaction on interface of electrolyte/Li‐metal without a stable solid–electrolyte–interface (SEI) layer. A stable protection layer is formed on Li metal anode by in situ transferring the coating layer from polymer separator. The Li anode protection strategy is developed with an in situ formed protection layer transferred through the reduction of a coating layer on polymer separator. A PbZr_0.52Ti_0.48O₃ (PZT) coating layer on polypropylene (PP) separator is reduced by Li metal anode to produce a Pb metal containing composite layer, which could form Pb–Li alloy and adhere to the surface of Li metal anode after the reaction and improves the Li plating/stripping efficiency owing to the formation of a more homogenized electric field. Both the Li/Li symmetric cells and LiFePO₄/Li cells with this PZT precoated PP separators exhibit significantly improved Coulombic efficiency and cycling life.     

Intercalated Electrolyte with High Transference Number for Dendrite‐Free Solid‐State Lithium Batteries

Solid‐state lithium (Li) batteries using solid electrolytes and Li anodes are highly desirable because of their high energy densities and intrinsic safety. However, low ambient‐temperature conductivity and poor interface compatibility of solid electrolytes as well as Li dendrite formation cause large polarization and poor cycling stability. Herein, a high transference number intercalated composite solid electrolyte (CSE) is prepared by the combination of a solution‐casting and hot‐pressing method using layered lithium montmorillonite, poly(ethylene carbonate), lithium bis(fluorosulfonyl)imide, high‐voltage fluoroethylene carbonate additive, and poly(tetrafluoroethylene) binder. The electrolyte presents high ionic conductivity (3.5 × 10^?4 S cm^?1), a wide electrochemical window (4.6 V vs Li⁺/Li), and high ionic transference number (0.83) at 25 °C. In addition, a 3D Li anode is also fabricated via a facile thermal infusion strategy. The synergistic effect of high transference number intercalated electrolyte and 3D Li anode is more favorable to suppress Li dendrites in a working battery. The solid‐state batteries based on LiFePO₄ (Al₂O₃ @ LiNi_0.5Co_0.2Mn_0.3O₂), CSE, and 3D Li deliver admirable cycling stability with discharge capacity 145.9 mAh g^?1 (150.7 mAh g^?1) and capacity retention 91.9% after 200 cycles at 0.5 C (92.0% after 100 cycles at 0.2 C) at 25 °C. This work affords a splendid strategy for high‐performance solid‐state battery.     

Ultra-Stable Zn Anode Enabled by Fiber-Directed Ion Migration Using Mass-Producible Separator

Aqueous zinc-ion battery (AZB) is a promising candidate for next-generation energy storage owing to inherent safety and low cost. However, AZBs are currently plagued by Zn dendrite growth and undesirable side-reactions, leading to poor cycling stability and premature failure. To restrain the uncontrollable Zn growth, a unique separator is developed based on polyacrylonitrile/graphene oxide (abbreviated as PG) composite nanofibers, which contain abundance of zincophilicity functional groups to regulate the migration and distribution of Zn²⁺ ions in the separator. It is demonstrated that the cyano ligands on PG not only facilitate the dehydration of solvated Zn²⁺ ions prior to deposition, but also form fast lanes to enable homogenous scattering of deposition spots. Benefiting from these features, the PG separator offers a high ionic conductivity of 7.69 mS cm^-1 and a transference number of 0.74 for Zn²⁺. The Zn||Zn symmetrical cells with PG separators achieve an ultra-stable cycle life over 13 000 h. Zn||Zn_0.27V₂O₅ full batteries with PG separators retain 71.5% of the original capacity after 2800 cycles at a high current density of 2 A g^-1. This study offers future research directions toward the design of multifunctional separators to overcome the limits of Zn metal anode in AZBs.     

Janus‐Faced,Dual‐Conductive/Chemically Active Battery Separator Membranes

Battery separators are supposed to be electrical insulators to prevent internal short‐circuit failure between electrodes as well as having porous channels to allow ion transport. Here, as a multifunctional membrane strategy to dispel this stereotypical belief about battery separators, a new class of Janus‐faced, dual (ion/electron)‐conductive/chemically active battery separators (denoted as “Janus separators”) based on a heterolayered nanofiber mat architecture is demonstrated. The Janus separator, which is fabricated through in‐series, concurrent electrospraying/electrospinning processes, consists of an ion‐conductive/metal ion‐chelating support layer (a mat of densely packed, thiol‐functionalized silica particles spatially besieged by polyvinylpyrrolidone/polyacrylonitrile nanofibers) and a dual‐conductive top layer (a thin mat of polyetherimide nanofibers wrapped with multi‐walled carbon nanotubes). The support layer acts as a chemical trap that can capture heavy metal ions dissolved in liquid electrolytes and the top layer serves as an upper current collector for cathodes to boost the redox reaction kinetics. Notably, the unusual porous microstructure of the top layer is theoretically elucidated using molecular dynamics simulation. Benefiting from such material/structural uniqueness, the Janus separator enables significant improvements in fast‐rate charge/discharge reactions (even for high‐mass loading cathodes) and in the high‐temperature cycling performance, which lie far beyond those achievable with conventional polyethylene separators.     

A Self‐Standing and Flexible Electrode of Li4Ti5O12 Nanosheets with a N‐Doped Carbon Coating for High Rate Lithium Ion Batteries

Flexible energy‐storage devices have attracted growing attention with the fast development of bendable electronic systems. Thus, the search for reliable electrodes with both high mechanical flexibility and excellent electron and lithium‐ion conductivity has become an urgent task. Carbon‐coated nanostructures of Li₄Ti₅O₁₂ (LTO) have important applications in high‐performance lithium ion batteries (LIBs). However, these materials still need to be mixed with a binder and carbon black and pressed onto metal substrates or, alternatively, by be deposited onto a conductive substrate before they are assembled into batteries, which makes the batteries less flexible and have a low energy density. Herein, a simple and scalable process to fabricate LTO nanosheets with a N‐doped carbon coating is reported. This can be assembled into a film which can be used as a binder‐free and flexible electrode for LIBs that does not require any current collectors. Such a flexible electrode has a long life. More significantly, it exhibits an excellent rate capability due to the thin carbon coating and porous nanosheet structures, which produces a highly conductive pathway for electrons and fast transport channels for lithium ions.     

Dendrite-Free Lithium Metal Battery Enabled by Dendritic Mesoporous Silica Coated Separator

Concentration polarization-induced lithium dendrites seriously impede the practical application of high-energy-density lithium metal batteries. Porous materials that aim to inhibit lithium dendrites are extensively explored. However, their effects are still limited by the intrinsic features of the pores, especially channel geometry and surface properties. Herein, a separator modification strategy of blocking “dendritic deposition” via “dendritic channels” is proposed. A porous shield-like film is formed on the polypropylene separator through the close packing of ultra-small (≈100 nm) silica nanospheres with unique dendritic mesopores (DMS). Besides the hierarchical pores homogenizing the ion flux, the DMS film also provides abundant Si(OH)_x groups, preferentially adsorbing the TFSI⁻ in the electrolyte and accelerating the transport of Li⁺. Most notably, the dendritic mesochannels with high complexity can diversify the growth directions of lithium and contribute to a more substantial homogenizing process of Li⁺. Consequently, a dendrite-free deposition with 1000 stable cycles in Li|Li symmetric cells even at 10 mA cm⁻² is achieved. This study provides a scalable approach for the fabrication of mesoporous separators and offers a fresh perspective on the future design of advanced separators utilized for dendrite suppression.     

Composite Separators for Robust High Rate Lithium Ion Batteries

Lithium ion batteries (LIBs) are one of the most potential energy storage devices among various rechargeable batteries due to their high energy/power density, long cycle life, and low self-discharge properties. However, current LIBs fail to meet the ever-increasing safety and fast charge/discharge demands. As one of the main components in LIBs, separator is of paramount importance for safety and rate performance of LIBs. Among the various separators, composite separators have been widely investigated for improving their thermal stability, mechanical strength, electrolyte uptake, and ionic conductivity. Herein, the challenges and limitations of commercial separators for LIBs are reviewed, and a systematic overview of the state-of-the-art research progress in composite separators is provided for safe and high rate LIBs. Various combination types of composite separators including blending, layer, core–shell, and grafting types are covered. In addition, models and simulations based on the various types of composite separators are discussed to comprehend the composite mechanism for robust performances. At the end, future directions and perspectives for further advances in composite separators are presented to boost safety and rate capacity of LIBs.     

Facile Design of Sulfide-Based all Solid-State Lithium Metal Battery: In Situ Polymerization within Self-Supported Porous Argyrodite Skeleton

All solid-state batteries holds great promise for superiorly safe and high energy electrochemical energy storage. The ionic conductivity of electrolytes and its interfacial compatibility with the electrode are two critical factors in determining the electrochemical performance of all solid-state batteries. It is a great challenge to simultaneously demonstrate fantastic ionic conductivity and compatible electrolyte/electrode interface to acquire a well-performed all solid-state battery. By in situ polymerizing poly(ethylene glycol) methyl ether acrylate within a self-supported 3D porous Li-argyrodite (Li₆PS₅Cl) skeleton, the two bottlenecks are tackled successfully at once. As a result, all solid-state lithium metal batteries with a 4.5 V LiNi_0.8Mn_0.1Co_0.1O₂ cathode designed by this integrated strategy demonstrates a high Coulombic efficiency exceeding 99% at room temperature. Solid-state nuclear magnetic resonance data suggest that Li⁺ mainly migrates along the continuous Li₆PS₅Cl phase to result in a room temperature conductivity of 4.6 × 10⁻⁴ S cm⁻¹, which is 128 times higher than that of the corresponding polymer. Meanwhile, the inferior solid–solid electrolyte/electrode interface is integrated via in situ polymerization to lessen the interfacial resistance significantly. This study thereby provides a very promising strategy of solid electrolyte design to simultaneously meet both high ionic conductivity and good interfacial compatibility towards practical high-energy-density all solid-state lithium batteries.     

Highly‐Cyclable Room‐Temperature Phosphorene Polymer Electrolyte Composites for Li Metal Batteries

Despite significant interest toward solid‐state electrolytes owing to their superior safety in comparison to liquid‐based electrolytes, sluggish ion diffusion and high interfacial resistance limit their application in durable and high‐power density batteries. Here, a novel quasi‐solid Li⁺ ion conductive nanocomposite polymer electrolyte containing black phosphorous (BP) nanosheets is reported. The developed electrolyte is successfully cycled against Li metal (over 550 h cycling) at 1 mA cm^?2 at room temperature. The cycling overpotential is dropped by 75% in comparison to BP‐free polymer composite electrolyte indicating lower interfacial resistance at the electrode/electrolyte interfaces. Molecular dynamics simulations reveal that the coordination number of Li⁺ ions around (trifluoromethanesulfonyl)imide (TFSI^?) pairs and ethylene‐oxide chains decreases at the Li metal/electrolyte interface, which facilitates the Li⁺ transport through the polymer host. Density functional theory calculations confirm that the adsorption of the LiTFSI molecules at the BP surface leads to the weakening of N and Li atomic bonding and enhances the dissociation of Li⁺ ions. This work offers a new potential mechanism to tune the bulk and interfacial ionic conductivity of solid‐state electrolytes that may lead to a new generation of lithium polymer batteries with high ionic conduction kinetics and stable long‐life cycling.     

N‐Doped Graphene‐SnO2 Sandwich Paper for High‐Performance Lithium‐Ion Batteries

A new facile route to fabricate N‐doped graphene‐SnO₂ sandwich papers is developed. The 7,7,8,8‐tetracyanoquinodimethane anion (TCNQ^?) plays a key role for the formation of such structures as it acts as both the nitrogen source and complexing agent. If used in lithium‐ion batteries (LIBs), the material exhibits a large capacity, high rate capability, and excellent cycling stability. The superior electrochemical performance of this novel material is the result from its unique features: excellent electronic conductivity related to the sandwich structure, short transportation length for both lithium ions and electrons, and elastomeric space to accommodate volume changes upon Li insertion/extraction.