Abstract:Hydrochar from hydrothermal carbonization of biomass are regarded as one of the most promising electrode materials for supercapacitors owing to its low-cost, high carbon content and porosity. However, there were few studies on durian shell hydrochar via hydrothermal carbonization as a high-value porous carbon material. In order to explore the performance of durian shell hydrochar as electrode material, the hydrochar was prepared from durian shell via one-step hydrothermal carbonzation process at 250℃, 10h and liquid-solid ratio of 10g/g. The elemental composition, structural characteristics and electrochemical properties of the hydrochar were analyzed. The results showed that the C content of the hydrochar was 70.29% and its O content was 16.96%. There were abundant oxygen-containing functional groups on the surface of durian shell hydrochar. The prepared hydrochar contained appreciable amount of amorphous carbon, and some were close to graphitization. Moreover, the hydrochar exhibited a BET specific surface area of 38.74m2/g and an average pore size of 4.67nm. In a three electrode system with 6mol/L KOH as electrolyte, the cyclic voltammetry curve of the hydrochar prepared as working electrode presented a symmetrical rectangular shape. The partial pseudo capacitance was provided by the functional groups containing heteroatoms. The galvanostatic charge-discharge curve approximately presented triangle shape. Durian shell hydrochar exhibited a high specific capacitance of 344.83F/g at 1A/g and good rate performance. The electrochemical impedance curve showed a steep slope in the low frequency region, which showed good electrical properties and certain cycle stability. The achieved electrochemical performance demonstrated that durian shell hydrochar could be used as electrode materials for supercapacitors and low-cost energy storage materials.
