A molten salt route to binder-free CeO2 on carbon cloth for high performance supercapacitors

Cerium oxide is one of the most abundant and environment-benignity rare earth oxides, which is thus of interesting to explore its feasibility to serve as a safe and efficient candidate for supercapacitor electrodes. We report herein a facile one-step molten salt method to synthesize CeO 2 nanoparticles abundant in surface oxygen vacancies , which are directly grown on a carbon cloth (CeO 2 @CC). The CeO 2 @CC exhibits a high specific capacitance of 811.5 mF cm −2 at the current density of 5 mA cm −2 in −0.8–0 V, with a good capacitance retention of 86.3 % at 5 mA cm −2 after 10,000 cycles in 6 M KOH aqueous electrolyte. When assembled with a Co 3 O 4 @CC positive electrode , the Co 3 O 4 @CC//CeO 2 @CC asymmetric supercapacitor achieves an energy density of 0.11 mWh cm −2 at a power density of 3.25 mW cm −2 . Both the abundant oxygen vacancies and the conductive carbon cloth contribute to the electrochemical performance. This work suggests that CeO 2 could be a candidate material for high performance supercapacitors .