Energy and power performance of electrochemical double-layer capacitors based on molybdenum carbide derived carbon

Cyclic voltammetry, constant current charge/discharge, and electrochemical impedance spectroscopy have been applied to establish the electrochemical characteristics for electric double-layer capacitor (EDLC) consisting of the 1 M (C₂H₅)₃CH₃NBF₄ electrolyte in acetonitrile and micro/mesoporous carbon electrodes prepared from Mo₂C, noted as C(Mo₂C). The N₂ sorption (total BET specific surface area (S_BET ≤ 1855 m² g⁻¹), micropore area (S_micro ≤ 1823 m² g⁻¹), total pore volume (V_tot ≤ 1.399 m³ g⁻¹) and pore size distribution (average NLDFT pore width d_NLDFT ≥ 0.89 nm) values obtained have been correlated with the electrochemical characteristics for EDLCs (region of ideal polarizability (ΔV = 3.0 V), characteristic time constant (τ_R = 1.05 s), gravimetric capacitance (C_m ≤ 143 F g⁻¹)) dependent strongly on the C(Mo₂C) synthesis temperature. High gravimetric energy (35 Wh kg⁻¹) and gravimetric power (237 kW kg⁻¹) values, normalised to the total active mass of both C(Mo₂C) electrodes, synthesised at T_synt = 800 °C, have been demonstrated at cell voltage 3.0 V and T = 20 °C.