Fig. 6

Electrode efficiency. Detailed legend: a Capacitance retention of the different electrodes and b charge/discharge efficiency. c Charge-discharge cycle of one and three layers of Gr/CeO x . d Similar for the Gr/WO3 hybrid
Electrode efficiency. Detailed legend: a Capacitance retention of the different electrodes and b charge/discharge efficiency. c Charge-discharge cycle of one and three layers of Gr/CeO x . d Similar for the Gr/WO3 hybrid