To improve lignin function in KMnO 4 reduction through one-step hydrothermal carbonization (HTC), the HTC method must be modified to produce MnO 2 -hydrochar. This study proposed an HTC process with two-step heating to enhance the electrochemical performance of hydrochar. HTC is conducted in two-step heating at 100 °C (4 h) followed by 200 °C (8 h). The highest specific capacitance and kinetic current density of 86.76 F/g and 0.32 mA/cm 2 were obtained from the KMnO 4 -NH 4 OH solution. These findings show that implementing two-step heating in HTC can modify the mechanism and improve the performance of hydrochar.