Sub-nanometric Manganous Oxide Clusters in Nitrogen Doped Mesoporous Carbon Nanosheets for High-Performance Lithium–Sulfur Batteries

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