Freestanding Needle Flower Structure CuCo2S4 on Carbon Cloth for Flexible High Energy Supercapacitors With the Gel Electrolyte

Tian Xie; Jinxiao Xu; Jie Wang; Chuanli Ma; Linghao Su; Fengying Dong; Liangyu Gong

doi:10.3389/fchem.2020.00062

Freestanding Needle Flower Structure CuCo₂S₄ on Carbon Cloth for Flexible High Energy Supercapacitors With the Gel Electrolyte

Front Chem. 2020 Feb 27:8:62. doi: 10.3389/fchem.2020.00062. eCollection 2020.

Authors

Tian Xie¹, Jinxiao Xu¹, Jie Wang¹, Chuanli Ma¹, Linghao Su¹, Fengying Dong¹, Liangyu Gong¹

Affiliation

¹ College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, China.

Abstract

A facile hydrothermal approach was adopted to the direct synthesis of bimetallic sulfide (CuCo₂S₄) on carbon cloth (CC) without binders for the supercapacitor's electrodes. A possible formation mechanism was proposed. The prepared bimetallic electrode exhibited a high specific capacitance (Csp) of 1,312 F·g^-1 at 1 A·g^-1, and an excellent capacitance retention of 94% at 5 A·g^-1 over 5,000 cycles. In addition, the asymmetric supercapacitor (CuCo₂S₄/CC//AC/CC) exhibited energy density (42.9 wh·kg^-1 at 0.8 kW·kg^-1) and outstanding cycle performance (80% initial capacity retention after 5,000 cycles at 10 A·g^-1). It should be noted that the electrochemical performance of a supercapacitor device is quite stable at different bending angles. Two charged devices in series can light 28 red-colored LEDs (2.0 V) for 5 min. All of this serves to indicate the potentially high application value of CuCo₂S₄.

Keywords: CuCo2S4; flexible electrode; nanoneedles; pseudocapacitance; supercapacitors.