Aluminum-doping-based method for the improvement of the cycle life of cobalt–nickel hydroxides for nickel–zinc batteries

• Published in: Journal of colloid and interface science 2021-04, Vol.587, p.693-702
• Main Authors: Zhu, Xinqiang, Wu, Yatao, Lu, Yingzhuo, Sun, Yangyi, Wu, Qiang, Pang, Yajun, Shen, Zhehong, Chen, Hao
• Format: Article
• Language: English
• Subjects: Al doping; Cathode; Cycle life; Hydroxide; Ni-Zn battery
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2020.11.029

[Display omitted] •A method is developed to prepare Al-doped Co-Ni double hydroxides (Al-CoNiDH) on CC.•Al-doing depresses the transition of crystal phase and microstructure in the cycling.•After cycling, capacity retention of Al-CoNiDH-5% is 2.5 times that of Al-CoNiDH-0%•Al-CoNiDH-5%//Zn battery has >14% rise in the cycle life vs. Al-CoNiDH-0%//Zn battery. The unsatisfactory cycle life of nickel-based cathodes hinders the widespread commercial usage of nickel–zinc (Ni–Zn) batteries. The most frequently used methods to improve the cycle life of Ni-based cathodes are usually complicated and/or involve using organic solvents and high energy consumption. A facile process based on the hydrolysis-induced exchange of the cobalt-based metal-organic framework (Co-MOF) was developed to prepare aluminum (Al)-doped cobalt–nickel double hydroxides (Al-CoNiDH) on a carbon cloth (CC). The entire synthesis process is highly efficient, energy-saving, and has a low negative impact on the environment. Compared to undoped cobalt–nickel double hydroxide (Al-CoNiDH-0%), the as-prepared Al-CoNiDH as the electrode material displays a remarkably improved cycling stability because the Al-doping successfully depresses the transition in the crystal phase and microstructure during the long cycling. Benefiting from the improved performance of the optimal Al-CoNiDH electrode (Al-CoNiDH-5% electrode), the as-constructed aqueous Ni–Zn battery with Al-CoNiDH-5% as the cathode (Al-CoNiDH-5%//Zn) displays more than 14% improvement in the cycle life relative to the Al-CoNiDH-0%//Zn battery. Moreover, this Al-CoNiDH-5%//Zn battery achieves a high specific capacity (264 mAh g−1), good rate capability (72.4% retention at a 30-fold higher current), high electrochemical energy conversion efficiency, superior fast-charging ability, and strong capability of reversible switching between fast charging and slow charging. Furthermore, the as-assembled quasi-solid-state Al-CoNiDH-5%//Zn battery exhibits a decent electrochemical performance and satisfactory flexibility.