Performance of carbon-coated nano-ZnO prepared by carbonizing gel precursor as anodic material for secondary alkaline Zn batteries

• Published in: Transactions of Nonferrous Metals Society of China 2019-10, Vol.29 (10), p.2151-2159
• Main Authors: PENG, Ke, ZHANG, Zhi-jian, ZHAO, Ze-jun, YANG, Chao, TIAN, Zhong-liang, LAI, Yan-qing
• Format: Article
• Language: English
• Subjects: carbon-coated nano-ZnO; porous hierarchical architecture; sol−gel method; Zn−Ni battery
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(19)65121-6

Although carbon coating can improve the cycle life of anode for alkaline Zn batteries, the specific capacity reported is still lower compared with nanosized ZnO. Herein, carbon-coated nanosized ZnO (nano-ZnO@C) was synthesized by one-step heat treatment from a gel precursor in N2. Commercial ZnO and homemade ZnO prepared similarly in air atmosphere were studied for comparison. Structure analysis displayed that both nano-ZnO@C and homemade ZnO had a porous hierarchical agglomerated architecture produced from primary nanoparticles with a diameter of approximately 100 nm as building blocks. Electrochemical performance measurements showed that nano-ZnO@C displayed the highest electrochemical activity, the lowest electrode resistance, the highest discharge capacity (622 mA·h/g), and the best cyclic stability. These properties were due to the combination of nanosized ZnO and the physical capping of carbon, which maintained the high utilization efficiency of nano-ZnO, and simultaneously prevented dendrite growth and densification of the anode.