Electrochemical Performance of Sandwich-Like Porous Co₃O₄ Nanostructures on Nickel Foam

Co₃O₄ is a good anode candidate for high-performance lithium ion batteries (LIBs), attributed to its high specific capacity. However, due to its poor conductivity and significant volume expansion during electrochemical reactions, electrochemical performance of Co₃O₄ electrode is quite poor for practical applications. Co₃O₄ electrodes with various micro-/nanostructures have been designed and synthesized but their performances are still unsatisfied. In this study, we propose and develop a novel sandwich type of Co₃O₄ nanostructures by adjusting the ratio of ammonium fluoride and urea during hydrothermal reactions. When this sandwich-like Co₃O₄ composite electrode was used as the electrode for LIBs, it retained an outstanding reversible capacity of 857 mAh g⁻¹ after 70 cycles at a current density of 500 mA g⁻¹. When the current density was increased to 1000 mA g⁻¹, the reversible capacity was kept at 865 mAh g⁻¹ with insignificant changes of its capacity.