Effects of various electrolytes on the electrochemistry performance of Mn3O4/carbon cloth to ultra-flexible all-solid-state asymmetric supercapacitor

Abstract

Rapid developing flexible electronics, such as flexible screens, sensors and wearable devices, make them forward to invent portable and flexible energy storage systems. Flexible supercapacitors possess quick charge-discharge, high power density, environmentally friendly and flexible characteristics, which highly cater to the growing market demands. In supercapacitors, electrolyte is one of the key factors affecting their performance. Herein, we demonstrate that a self-assembly Mn3O4/carbon cloth (Mn3O4/CC) electrode is synthesized successfully by a two-step hydrothermal method. In a three electrodes system, the Mn3O4/CC electrode is tested in Na2SO4 and KOH respectively. The results reveal that Mn3O4/CC exhibits higher specific capacitance (555 mF cm−2 at 1 mA cm−2) and lower internal resistance in KOH. On the other hand, it expresses nearly no loss in the cycle stability test (99% retention after 2000 cycles) in Na2SO4. The all-solid-state asymmetric supercapacitor presents a maximum energy density reaching 25 μWh cm−2 with a power density of 0.64 mW cm−2. It also presents ultra-high flexibility (bending and twisting for 200 times) and superior cycling performance (99.3% after 2000 cycles). Hence, the Mn3O4/CC electrode is of great prospect in the application of flexible electronic devices.