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

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.