Design of high-performance transition metal sulfide electrode materials and its application in supercapacitors

Abstract

In this paper, the starting point is to create a large surface area, multi-metal cooperative composite material, and then add lithium to enhance the capacitance of the material to build a high-performance and high-stability electrode material. The CoMnLi hydroxide is synthesized on the metal organic framework Ni-BTC, and the composite is vulcanized as Ni-BTC@CoMnLiS using a solvent-thermal process. Moreover, the electrochemical properties electrode materials prepared under different conditions are investigated. It is eventually discovered that the electrode material prepared using water as a solvent having the best electrochemical performance at a reaction time of 6 h, and it is named Ni-BTC@Co2.13Mn1.78LiS4.52#6 (N@CMLS#6). The N@CMLS#6 electrode material has a high specific capacity (1040C g−1, 1 A g−1) and an eminent cycling stability (87.94 %, 10,000 cycles). In addition, the asymmetric supercapacitors devices (N@CMLS#6//AC) exhibit large energy density (82.14 W h kg−1, 800 W kg−1) and good cycle life (85.62 % of the original capacity after 10,000 charge-discharge cycles). Connecting two asymmetric supercapacitors (ASC) devices in series may light up tiny Light Emitting Diode (LED) lights, demonstrating its practical utility.