Boosting electrochemical supercapacitor performances with three-dimensional porous boron-doped diamond film
Uniform three-dimensional porous boron-doped diamond (P-BDD) film is deposited on titanium substrate through chemical vapor deposition and employed as an efficient potential electrode for electrochemical double-layer supercapacitor. The electrochemical responses of BDD electrodes are evaluated by cyclic voltammetry and galvanostatic charge/discharge techniques. P-BDD film delivers a specific capacitance of 6.02 mF cm−2 under scan rate 10 mV s−1, 12.4 times of flat BDD film in 0.1 M H2SO4 electrolyte in three-electrode configuration. Furthermore, operating voltage window of the symmetric device composing of two pieces of P-BDD electrodes could expand to 2.0 V and lighten a yellow light-emitting diode, where the single device presents an admirable energy density of 1.45 μWh cm−2 and power density of 0.5 mW cm−2. Moreover, P-BDD film exhibits favorable self-discharge behavior with low leakage current as small as 14.9 µA and presents remarkable cycling stability with capacitance retention of 91.6% after 10000 continuous cycles. The boosting electrochemical performances can be attributed to the synergistic effect between BDD film itself possessing excellent physical-chemical features and three-dimensional porous structure, which corroborate the P-BDD film potential candidate as future supercapacitor application.