Improved electrochemical performance of yolk-shell structured SnO2@void@C porous nanowires as anode for lithium and sodium batteries

Various yolk-shell structured particles designed for large volume expansion materials for lithium-ion storage have been reported, the cycle stability and coulombic efficiency can be effectively improved through such structure design. SnO2 has high theoretical capacity of 1494 mA h g−1 and 1378 mA h g−1 for lithium and sodium storage, respectively. The large volume expansion problem of SnO2 has long been considered as the primary reason for the capacity fading of SnO2 based anode materials. In this paper, the yolk-shell structured SnO2 porous nanowire has been designed, and this unique yolk-shell structure is reported as anode materials for lithium and sodium-ion storage for the first time. The yolk-shell structured porous nanowires deliver significantly improved cycle stability and coulombic efficiency as active material for both lithium and sodium-ion storage compared with that of pure SnO2 porous nanowires. It exhibits a high and stable capacity of 1150 mA h g−1 at current density of 200 mA g−1 for lithium-ion storage, and a capacity of 401 mA h g−1 at current density of 50 mA g−1 after 50 cycles for sodium-ion storage.