Synthesis of ZnCo₂O₄ microspheres with Zn_0.33Co_0.67CO₃ precursor and their electrochemical performance

Zn_0.33Co_0.67CO₃ (ZCCO) microspheres are fabricated by a facile solvothermal method at different temperatures, and ZnCo₂O₄ (ZCO) microspheres were further obtained by pyrolysis of the relative ZCCO precursors at 450 °C. All samples were characterized by X-ray diffractometer, Fourier transform infrared spectra, thermogravimetric, scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller (BET). Their electrochemical properties were investigated as the anode materials for the lithium-ion battery applications. The results showed that both the ZCCO and ZCO electrodes possess high specific capacities, and the synthesis temperature greatly influenced their performances. Compared with the synthesized of 180 °C, the synthesized of 200 °C (ZCCO-200) exhibited higher discharge capacity (1530 mAh g⁻¹) and better rate performance with the reversible capacity of 876 mAh g⁻¹ after 70 cycles under the voltage range of 0.01–3.0 V at the current density of 100 mA g⁻¹. The as-obtained ZCO microspheres from the pyrolysis of ZCCO-200 also exhibited higher discharge capacity of 1416 mAh g⁻¹ and better cycling stability (741 mAh g⁻¹ after 70 cycles) than that for the microspheres from the pyrolysis of ZCO-180, indicating that the electrochemical properties of ZCO may be related to the electrochemical performance of ZCCO. Our present work suggested that both the ZCCO and ZCO microspheres can be promising candidates as novel anode materials for lithium-ion battery applications.