Synthesis and Characterization of ZnO from Thermal Decomposition of Precipitated Zinc Oxalate Dihydrate as an Anode Material of Li-Ion Batteries

Abstract

Zinc oxide (ZnO) is one of the most promising materials applied in Li-ion batteries. In this research, ZnO was synthesized by the thermal decomposition of zinc oxalate dihydrate. This precursor was obtained from the precipitation process of zinc sulfate with oxalic acid. In-depth studies were carried out on the effect of various heating temperatures of zinc oxalate dihydrate precursors on ZnO synthesis. The as-prepared materials were characterized by XRD, SEM, and FTIR. Based on the XRD analysis, the presence of the ZnO-wurtzite phase can be confirmed in samples heated at temperatures above 400 °C. Meanwhile, SEM-EDX results showed that the ZnO particles have a micron size. Cells with ZnO samples as anodes have low columbic efficiency. In contrast, cells with ZnO/Graphite composite anodes have a relatively large capacity compared to pure graphite anodes. Overall, based on the consideration of the characterization results and electrochemical performance, the optimal sintering temperature to obtain ZnO is 600 °C with a cell discharge capacity of ZnO anode and in the form of graphite composites is 356 mAh/g and 450 mAh/g, respectively. This suggests that ZnO can be used as an anode material and an additive component to improve commercial graphite anodes’ electrochemical performance.

Keywords

• Li-ion battery
• ZnO
• anode
• precipitation
• sintering