Pseudocapacitance-dominated high-performance and stable lithium-ion batteries from MOF-derived spinel ZnCo2O4/ZnO/C heterostructure anode

Abstract

Spinel ZnCo₂O₄/ZnO/C hierarchically porous structures were successfully synthesized by two-step annealing of cyanide-bridged coordination polymer precursors. Such hierarchically porous structures exhibit a regular cube structure and provide a large surface area, which provides excellent charge transport kinetics by promoting the charge transfer into the inside of the electrode materials. When used as the anode material of lithium ion batteries, the spinel ZnCo₂O₄/ZnO/C porous structures exhibit high capacity and excellent cycling stability with a capacity of 1100 mA h g⁻¹ at a current density of 0.1 A g⁻¹ and maintain 800 mA h g⁻¹ after 400 cycles at a current density of 1 A g⁻¹. Meanwhile, the spinel ZnCo₂O₄/ZnO/C porous structures also exhibit an excellent pseudocapacitive contribution ratio of 86% at a scan rate of 1 mV s⁻¹.