Electrodeposited Porous Mn1.5Co1.5O4/Ni Composite Electrodes for High-Voltage Asymmetric Supercapacitors

Materials

Thomas C.-K. Yang¹  Guan-Ting Pan¹  Siewhui Chong²  Chao-Ming Huang³ 

[1] Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan;Department of Chemical and Environmental Engineering, University of Nottingham, Selangor 43500, Malaysia;Department of Materials Engineering, Kun Shan University, Tainan 710, Taiwan;

关键词: spinel;    Ni foam;    electrodeposition;    gel electrolyte;    asymmetric supercapacitor;   

DOI  :  10.3390/ma10040370

来源: DOAJ

【 摘 要 】

Mesoporous Mn1.5Co1.5O4 (MCO) spinel films were prepared directly on a conductive nickel (Ni) foam substrate via electrodeposition and an annealing treatment as supercapacitor electrodes. The electrodeposition time markedly influenced the surface morphological, textural, and supercapacitive properties of MCO/Ni electrodes. The (MCO/Ni)-15 min electrode (electrodeposition time: 15 min) exhibited the highest capacitance among three electrodes (electrodeposition times of 7.5, 15, and 30 min, respectively). Further, an asymmetric supercapacitor that utilizes (MCO/Ni)-15 min as a positive electrode, a plasma-treated activated carbon (PAC)/Ni electrode as a negative electrode, and carboxymethyl cellulose-lithium nitrate (LiNO3) gel electrolyte (denoted as (PAC/Ni)//(MCO/Ni)-15 min) was fabricated. In a stable operation window of 2.0 V, the device exhibited an energy density of 27.6 Wh·kg−1 and a power density of 1.01 kW·kg−1 at 1 A·g−1. After 5000 cycles, the specific energy density retention and power density retention were 96% and 92%, respectively, demonstrating exceptional cycling stability. The good supercapacitive performance and excellent stability of the (PAC/Ni)//(MCO/Ni)-15 min device can be ascribed to the hierarchical structure and high surface area of the (MCO/Ni)-15 min electrode, which facilitate lithium ion intercalation and deintercalation at the electrode/electrolyte interface and mitigate volume change during long-term charge/discharge cycling.

【 授权许可】

Unknown