Solubility-dependent gelatination toward N-doped SnOx/C deriving from commercial SnO2 for the ultrastable lithium storage

More than 200% volume change is the major restriction for the practical application of Sn-based anode materials in lithium-ion batteries. In order to prepare carbon-coated structure by a facile, low-cost, facile and common method, the solubility-dependent gelatination of carboxylated chitosan is developed for the precursors of N-doped SnOx/C composites with commercial SnO2 nanoparticles as Sn source. The phase, porosity and ratio of Sn/C of the composites can be easily controlled by changing the raw materials ratio and calcination temperature. According to the results, N-doped SnOx/C anode material shows excellent stability (93.9% retention of the second cycle) and superior specific capacity (679.8 and 542.3 mAh g(-1) after 300 cycles at 200 mA g(-1) and 1000 mA g(-1), respectively). This strategy lights on the illuminating design of 3D carbon-coated Sn-based anode by liquid carbon source and commercial solid tin source, which can improve electrochemical performance for next-generation lithium-ion batteries.