N, S‐Codoped 3D Carbon Protected Nanoporous MnS With Record High Sodium Ion Storage Performance for Potential Industry Applications
Jun Miao, Naixuan Ci, Boxuan Cao, Guoqiang Xie, Xingjun Liu, Hua‐Jun Qiu
Abstract
Abstract With a high theoretical capacity, the MnS anode, however, exhibits a rather complex sodium diffusion kinetics and poor mechanical stability that hinder its application in sodium‐ion batteries (SIBs). In this work, a simple, economical, and scalable strategy is developed to inherently coat nanoporous MnS with a 3D N, S co‐doped thin carbon layer by using commercially available MnCO 3 as precursors. Specifically, the strategy involves a two‐step annealing process, which converts the MnCO 3 microparticles into nanoporous Mn 2 O 3 and MnS step by step. The 3D N, S codoped carbon layer is in situ formed during the second annealing process by first coating the nanoporous Mn 2 O 3 with a polyaniline layer. Due to the inherent 3D carbon protection and the strong electronic interaction between N, S dopants and MnS, the N, S codoped carbon protected MnS obtained at 900 °C (NS‐C@MnS‐900) anode displays a high specific capacity of 845 mAh g −1 at 0.1 A g −1 , which is higher than all reported MnS‐based SIB anodes. It also shows an outstanding cyclability and rate performance, maintaining a stable capacity of ≈493 mAh g −1 after 1300 cycles at 10 A g −1 , which is also the best according to knowledge. These exceptional electrochemical performances and the scalable/simple/low‐cost synthesis make the NS‐C@MnS‐900 attractive for industry application.