Sub-nanometric Manganous Oxide Clusters in Nitrogen\nDoped Mesoporous Carbon Nanosheets for High-Performance Lithium–Sulfur\nBatteries

Abstract

The\ngreatest challenge for lithium–sulfur (Li–S)\nbatteries application is the development of cathode hosts to address\nthe low conductivity, huge volume change, and shuttling effect of\nsulfur or lithium polysulfides (LiPs). Herein, we demonstrate a composite\nhost to circumvent these problems by confining sub-nanometric manganous\noxide clusters (MOCs) in nitrogen doped mesoporous carbon nanosheets.\nThe atomic structure of MOCs is well-characterized and optimized via\nthe extended X-ray absorption fine structure analysis and density\nfunctional theory (DFT) calculations. Benefiting from the unique design,\nthe assembled Li–S battery displays remarkable electrochemical\nperformances including a high reversible capacity (990 mAh g^–1 after 100 cycles at 0.2 A g^–1) and a superior\ncycle life (60% retention over 250 cycles at 2 A g^–1). Both the experimental results and DFT calculations demonstrate\nthat the well-dispersed MOCs could significantly promote the chemisorption\nof LiPs, thus greatly improving the capacity and rate performance.