Nickel/cobalt based materials for supercapacitors

• Published in: Chinese chemical letters 2018-12, Vol.29 (12), p.1731-1740
• Main Authors: Wang, Chenggang, Sun, Pengxiao, Qu, Guangmeng, Yin, Jiangmei, Xu, Xijin
• Format: Article
• Language: English
• Subjects: Battery-type materials; EDLCs; Hybrid supercapacitors; Nickel/cobalt based materials; Pseudocapacitors
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2018.12.005

We briefly summarize the fundamental mechanism of supercapacitors and classify them into three kinds according to the different energy storage mechanism. We further discuss the energy storage mechanism of nickel/cobalt based materials, and we suggest that these kinds of battery-type materials should be classified into hybrid supercapacitor instead of pseudocapacitors. [Display omitted] The electrode materials as the key component of supercapacitors have attracted considerable research interests, especially for nickel/cobalt based materials by virtue of their superior electrochemical performance with multiple oxidation states for richer redox reactions, abundant natural resources, lower prices and toxicity. There are many advanced electrodes based on the nickel/cobalt materials exploited for the application of supercapacitors, however, some controversial statements have induced some confusion. Herein, we refine the mechanism of energy storage for the nickel/cobalt based materials for supercapacitors and reclassify them into battery-type materials with the corresponding devices named as hybrid supercapacitors.