Electrochemical transformation method for the preparation of novel 3D hybrid porous CoOOH/Co(OH)2 composites with excellent pseudocapacitance performance

• Published in: Journal of power sources 2019-12, Vol.443, p.227278, Article 227278
• Main Authors: Yu, Yawei, Tan, Yurong, Yang, Bingqian, Yuan, Lefan, Shen, Xiaodong, Hu, Xiulan
• Format: Article
• Language: English
• Subjects: CoOOH/Co(OH)2; Cu foam; Electrochemical transformation; Hydrothermal method; Supercapacitor
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2019.227278

Novel 3D hybrid porous CoOOH/Co(OH)2 composites are prepared through the electrochemical transformation of the precursor that is synthesized using the hydrothermal method. The CoOOH/Co(OH)2 has a good specific area of 10.88 m2 g−1, which is obviously larger than the 1.48 m2 g−1 of the precursor. The CoOOH/Co(OH)2 has a high specific capacitance (4.721 F cm−2 at 2 mA cm−2) and good stability (94.4% capacitance retention after 5000 cycles at 64 mA cm−2). Furthermore, an asymmetric supercapacitor that is fabricated using CoOOH/Co(OH)2 and α-Fe2O3@carbon cloth has a high specific capacitance (1.667 F cm−2 at 2 mA cm−2) and excellent cyclic stability (103.6% capacitance retention after 10000 cycles at 80 mA cm−2). These fascinating electrochemical properties result from the 3D hybrid porous CoOOH/Co(OH)2 composites that formed during the transformation process, demonstrating their potential application as an electrode material for pseudocapacitors. •Cobalt precursor containing mainly Co3+ was synthesized using hydrothermal method.•The precursor translated into CoOOH/Co(OH)2 by the electrochemical transformation.•The CoOOH/Co(OH)2 has a high specific capacitance and good stability.