Cream roll-inspired advanced MnS/C composite for sodium-ion batteries: encapsulating MnS cream into hollow N,S-co-doped carbon rolls.

With advantages of high theoretical capacity and low cost, manganese sulfide (MnS) has become a potential electrode material for sodium-ion batteries (SIBs). However, complicated preparations and limited cycle life still hinder its application. Inspired by cream rolls in our daily life, a MnS/N,S-co-doped carbon tube (MnS/NSCT) composite with a 3D cross-linked tubular structure is prepared via an ultra-simple and low-cost method in this work. As the anode for SIBs, the cream roll-like MnS/NSCT composite has delivered the best electrochemical performance to date (the highest capacity of 550.6 mA h g at 100 mA g, the highest capacity of 447.0 mA h g after 1400 cycles at 1000 mA g, and the best rate performance of 319.8 mA h g at 10 000 mA g). Besides, according to several in situ and ex situ techniques, the sodium storage mechanism of MnS/NSCTs is mainly from a conversion reaction, and the superior electrochemical performance of MnS/NSCTs is mainly attributed to the unique cream roll-like structure. More importantly, this simple method may be feasible for other anode materials, which will greatly promote the development of SIBs.