摘要
The commercialization of lithium-sulfur(Li-S) batteries is obstructed by the sluggish sulfur electrochemical reaction,severe polysulfide shuttling effect,and damaging dendritic lithium growth.Herein,a threedimensional(3D) conductive carbon nanofibers skeleton-based bifunctional electrode host material is fabricated,which consists of a two-dimensional(2D) ultra-thin NiSe_(2)-CoSe_(2)heterostructured nanosheet built on one-dimensional(1D) carbon nanofibers(NiSe_(2)-CoSe_(2)@CNF).When serving as cathodic host,the heterostructured NiSe_(2)-CoSe_(2)@CNF offers a synergistic function of polysulfide confinement and catalysis conversion.The S/NiSe_(2)-CoSe_(2)@CNF cathode shows outstanding cycling stability of 0.03% capacity decay rate per cycle over 500 cycles at 1 C.As anodic host,the NiSe_(2)-CoSe_(2)@CNF with high-flux Li+diffusion property and good lithiophilic capability realizes dendrite-free Li plating/stripping behavior.Benefiting from these synergistically merits,the Li-S full cell with S/NiSe_(2)-CoSe_(2)@CNFILi/NiSe_(2)-CoSe_(2)@CNF electrodes exhibits excellent electrochemical performance including a high specific capacity of1021 mA h g^(-1)over 100 cycles at 0.2 C and reversible areal capacity of 3.05 mA h cm^(-2)under a high sulfur loading of 4.33 mg cm^(-2)at 0.1 C.The pouch cell also delivers ultra-stable Li/S electrochemistry.This study demonstrates a rational and universal electrode construction strategy for developing practical and high-energy Li-S batteries.
基金
financial support from the National Natural Science Foundation of China (52102236)
supported by the Foundation (KF202021) of the Key Laboratory of Pulp and Paper Science&Technology of Ministry of Education of China
the Overseas Faculty Supporting Project in Hebei Province (C20210335)。
