Zn2SnO4 particles coated with N-doped carbon as an anode material for lithium and sodium-ion batteries

Abstract

Zinc stannate (Zn2SnO4) is an attractive anode material because of its high theoretical capacities of approximately 1231 and 1004 mA h g−1 in lithium and sodium-ion batteries, respectively. However, attaining satisfactory electrochemical performance of Zn2SnO4 is challenging because of the low electrical and ionic conductivities as well as large volume expansion during the cycling. To overcome these problems, Zn2SnO4 nanoparticles are uniformly coated with N-doped carbon layers using dopamine as a carbon and nitrogen source. The thickness of the carbon layers is simply controlled to be about 4–8 nm by adjusting the self-polymerization degree of dopamine. The electrochemical properties of the Zn2SnO4/N-doped carbon composite are characterized, exhibiting excellent cycling performance with the reversible discharge capacities of approximately 992.4 and 324.4 mA h g−1 after the 100th cycle with the current densities of 60 and 32 mA g−1 in lithium and sodium-ion batteries, respectively.