A flexible cathode of nickel-manganese sulfide microparticles on carbon cloth for aqueous asymmetric supercapacitors with high comprehensive performance

Abstract

Herein, a flexible cathode with high performance, which consists of nickel (Ni)-manganese (Mn) sulfide (S) microparticles on activated carbon cloth (ACC), i.e., Ni–Mn–S/ACC, prepared by one-step electrodeposition of the Ni–Mn based compound and subsequent sulfurization is reported. The optimized Ni–Mn–S/ACC cathode has a high capacitance (∼12789.6 mF cm−2 at 1.0 mA cm−2), good rate performance (∼3352 mF cm−2 up to 60.0 mA cm−2) and cycling behavior (∼81.7% retention of the initial capacitance after 5000 cycles at 50 mA cm−2). An aqueous asymmetric supercapacitor assembled using the cathode of Ni–Mn–S/ACC, the anode of activated carbon on carbon cloth and the electrolyte of 6.0 M potassium hydroxide delivers a desirable energy density of ∼0.789 mWh cm−2 at 0.850 mW cm−2 and good cycling performance of ∼82.8% capacitance retention after 18,000 cycles at 25.0 mA cm−2 with the Coulombic efficiency around 100%.