Lithium–sulfur batteries are regarded as one of the most promising candidates for next‐generation rechargeable batteries. However, the practical application of lithium–sulfur (Li–S) batteries is seriously impeded by the notorious shuttling of soluble polysulfide intermediates, inducing a low utilization of active materials, severe self‐discharge, and thus a poor cycling life, which is particularly severe in high‐sulfur‐loading cathodes. Herein, a polysulfide‐immobilizing polymer is reported to address the shuttling issues. A natural polymer of Gum Arabic (GA) with precise oxygen‐containing functional groups that can induce a strong binding interaction toward lithium polysulfides is deposited onto a conductive support of a carbon nanofiber (CNF) film as a polysulfide shielding interlayer. The as‐obtained CNF–GA composite interlayer can achieve an outstanding performance of a high specific capacity of 880 mA h g−1 and a maintained specific capacity of 827 mA h g−1 after 250 cycles under a sulfur loading of 1.1 mg cm−2. More importantly, high reversible areal capacities of 4.77 and 10.8 mA h cm−2 can be obtained at high sulfur loadings of 6 and even 12 mg cm−2, respectively. The results offer a facile and promising approach to develop viable lithium–sulfur batteries with high sulfur loading and high reversible capacities.

Red phosphorus (P) has been recognized as a promising storage material for Li and Na. However, it has not been reported for K storage and the reaction mechanism remains unknown. Herein, a novel nanocomposite anode material is designed and synthesized by anchoring red P nanoparticles on a 3D carbon nanosheet framework for K-ion batteries (KIBs). The red P@CN composite demonstrates a superior electrochemical performance with a high reversible capacity of 655 mA h g at 100 mA g and a good rate capability remaining 323.7 mA h g at 2000 mA g , which outperform reported anode materials for KIBs. The transmission electron microscopy and theoretical calculation results suggest a one-electron reaction mechanism ofP + K + e → KP, corresponding to a theoretical capacity of 843 mA h g ,which is the highest value for anode materials investigated for KIBs. The study not only sheds light on the rational design of high performance red P anodes for KIBs but also offers a fundamental understanding of the potassium storage mechanism of red P.

Lithium–sulfur (Li–S) batteries suffer from sluggish sulfur redox reactions under high-sulfur-loading and lean-electrolyte conditions. Herein, a typical Co@NC heterostructure composed of Co nanoparticles and a semiconductive N-doped carbon matrix is designed as a model Mott–Schottky catalyst to exert the electrocatalytic effect on sulfur electrochemistry. Theoretical and experimental results reveal the redistribution of charge and a built-in electric field at the Co@NC heterointerface, which are critical to lowering the energy barrier of polysulfide reduction and Li2S oxidation in the discharge and charge process, respectively. With Co@NC Mott–Schottky catalysts, the Li–S batteries display an ultrahigh capacity retention of 92.1% and a system-level gravimetric energy density of 307.8 Wh kg–1 under high S loading (10.73 mg cm–2) and lean electrolyte (E/S = 5.9 μL mgsulfur –1) conditions. The proposed Mott–Schottky heterostructure not only deepens the understanding of the electrocatalytic effect in Li–S chemistry but also inspires a rational catalyst design for advanced high-energy-density batteries.

3860 mA h g −1 for metallic Li versus 372 mA h g −1 for graphite) and lowest redox voltage (−3.04 V versus standard hydrogen electrode) among all the anodes, exhibiting great promise as high-performance anode in the next-generation highenergy-density lithium-based rechargeable batteries. [3] Nevertheless, nearly infinite volume expansion/shrinkage and inhomogeneous stripping/plating behavior lead to the growth of dendritic behaviors of metallic Li, which would cause short circuits and other safety issues. [3b,4] Accompanied by large volume change, repeated fracture and repair of solid electrolyte interface (SEI) occurs during the charge/ discharge processes, which causes continuous consumption of active lithium and electrolyte, and finally inferior cycling stability. [5] Recently, extensive studies on electrode surface protection, composite structure, and electrolyte engineering have been conducted to improve the cycle life and safety hazards of metallic Li electrode. [6] However, highly overloaded lithium metal anodes (e.g., 500 µm for ≈100 mA h cm −2 ) and flooding amount of electrolytes were often employed for the evaluation of electrochemical performance of metallic Li. The use of thick Li metal anodes and excessive electrolyte does not support high energy density of batteries and are not feasible in practical applications. Therefore, high-performance ultrathin lithium metal anodes (e.g., 10-50 µm) that possess matched capacities with current cathodes are of key importance to practical battery application. However, the high homologous temperature (T h , for metallic lithium, T h is 0.66 at room temperature) of metallic Li at room temperature leads a strong influence of diffusion creep on its deformation, [7] and the resulting sticky nature and poor mechanical processability make it challenging to realize large-scale fabrication of ultrathin pure Li metal electrode by regular mechanical rolling operation.Free-standing ultrathin metallic Li foil cannot sustain operation for battery fabrication and large current in real application condition, it is of great importance for the employment of current collector with high conductivity and mechanical durability for the practical implantation of ultrathin metallic Li anode in high-energy-density batteries, which is similar to metal current collector for traditional porous electrodes (e.g., graphite on Cu foil). Cu foil is lithiophobic to molten lithium, which