Electrochemical reduced ITO for high-stability asymmetric supercapacitors

Indium tin oxide coated glass (ITO) is considered as an ideal conductive substrate for the optoelectronic devices due to its high conductivity, light transmittance and chemical and thermal stability. However, its application in supercapacitors is quite limited because of the poor interfacial adhesion between ITO and electrochemically active materials. In this study, by electrochemically reducing ITO film, we have significantly enhanced the adhesion between current collectors (R-ITO) and the electrochemically active materials (MnO2 and PEDOT) by forming In/Sn nano-particles at the R-ITO surface. The fabricated electrodes based on each material have delivered a specific capacitance over 30 mF cm −2 as well as an excellent cycling stability. Further, the obtained solid-state asymmetric supercapacitor based on R-ITO@MnO2 and R-ITO@PEDOT electrodes gives a high operating voltage of 1.5 V, an energy density of 4.6 μWh cm−2 and a prominent stability (capacitance retention of 93.2% after 2500 cycles).