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

Author: Pan Guan-Ting   Chong Siewhui   Yang Thomas C.-K.   Huang Chao-Ming  

Publisher: MDPI

E-ISSN: 1996-1944|10|4|370-370

ISSN: 1996-1944

Source: Materials, Vol.10, Iss.4, 2017-03, pp. : 370-370

Access to resources Favorite

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

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.