Excellent electrochemical properties of Mn₃O₄ cathode materials synthesized with the assistance of CTAB surfactant

Electrode materials are important indicators for evaluating the performance of electrochemical capacitors, and designing nanostructured materials with high specific capacitance and excellent cycling stability performance is an important way to enhance the performance of supercapacitors. In this study, cetyltrimethylammonium bromide (CTAB) was used as a cationic surfactant, and flower cluster-like Mn₃O₄ particles were prepared by the vesicle soft template method, and different concentrations of CTAB were set in order to investigate its effect on the formation and electrical properties of Mn₃O₄ nanoparticles. Physical and electrochemical characterization was carried out using various means such as XRD, SEM, TEM, BET, CV, EIS, and GCD. The results show that the Mn₃O₄ electrode material exhibits a higher specific capacitance of 261 F/g in 1 M Na₂SO₄ electrolyte when the current density is 0.5 A/g and still maintains 253 F/g when the current density is increased to 10 A/g. Excellent capacitance retention is observed after 10,000 cycles at a current density of 5 A/g (up to 93%). In addition, a Mn₃O₄//AC asymmetric supercapacitor (ASC) was assembled using Mn₃O₄ as the positive electrode and commercially available activated carbon (AC) as the negative electrode, and the device provided a maximum energy density of 30.56 Wh/kg at 452.74 W/kg.