Effects of annealing temperature on the electrochemical characteristics of ZnO microrods as anode materials of lithium-ion battery using chemical bath deposition

This study reports a facile synthesis of ZnO microrods using chemical bath deposition (CBD) for anode materials of lithium-ion batteries (LIB). During the synthesis, we controlled the uniformity, the density, and the diameter growth of ZnO microrods in order to find the optimum conditions. In particular, the effects of annealing temperature on the ZnO microrod morphology, structure, and electrochemical performances were further investigated. The size, alignment, and uniformity of the ZnO microrods were evaluated by scanning electron microscopy (SEM), while structural analysis was performed by X-ray diffraction (XRD) technique. The results showed that the annealing temperatures significantly influenced the ZnO microrod growth. We found the excellent experimental parameters were achieved at annealing temperature of 150 °C (ZnO_150) within 10 min and three seed layers, providing an average diameter of ~ 233.6 nm, crystallite size of 46.01 nm, and the density of 5.05 rods/μm ² . Among the other samples, the ZnO_150 microrods delivered the highest initial discharge capacity of 811 mAhg ⁻¹ with relatively stable capacity retention of ~ 82% after 80 cycles and excellent rate capability performance.