Core–shell-structured Mn₂SnO₄@Void@C as a stable anode material for lithium-ion batteries with long cycle life

Owing to its high theoretical specific capacity, Mn2SnO4 has been regarded as a promising electrode material for lithium-ion batteries. However, in suffering from huge volume expansion and pulverization amidst the alloying/dealloying processes, it presents difficulties in applications as an anode material. Herein, a core-shell-structured Mn2SnO4@Void@C anode material was successfully synthesized using a layer-wise assembly and selective etching method. Tetraethyl silicate (TEOS) and resorcinol formaldehyde resin, serving, respectively, as sacrificial template (SiO2) and carbon layer sources, were coated successively onto Mn2SnO4 particles. Adopting an alkali etching process, the SiO2 template was removed, and a Mn2SnO4@Void@C was therewith constructed. As Mn2SnO4 is well wrapped by a carbon shell and there are enough voids therein, its volume expansion whilst cycling can be significantly buffered. Moreover, the porous structure in Mn2SnO4@Void@C can provide convenient channels for ion transport and alleviate volume changes. Mn2SnO4@Void@C exhibits upgraded capacity and long cycling stability, since its specific capacity is maintained at 783.1 mA h g-1 at 100 mA g-1 after 150 cycles and at 553.3 mA h g-1 at 1000 mA g-1 after 1000 cycles.