Abstract: The activated carbon(AC1)was prepared from moso bamboo carbide by KOH activation and hydrochloric acid solution washing. Then AC1 sample was further treated with H₂O₂ oxidation-ultrasonic method to deeply remove the K⁺. The effects of different experimental conditions on the removal of K⁺ content of ACs were studied. The pore structures of the AC samples were characterized by N₂ adsorption-desorption isotherm, and electrochemical properties were characterized by cyclic voltammetry, constant current charge-discharge and electrochemical impedance spectroscopy. The results showed that high quality activated carbon(AC2)could be obtained under the conditions of mass fraction of H₂O₂ solution 0.6%, ultrasonic reaction temperature 60℃ and ultrasonic reaction time 8 h. And the K⁺ content was 52 mg/kg, specific surface area was 3 156 m²/g, pore volume was 1.625 cm³/g, ratio of mesopore was 79.8% and average pore size was 2.208 nm. For the electrochemical properties, it displayed a specific capacitance of 297 F/g and a high capacitance retention of 95% after 3 000 cycles. They increased by 28% and 6 percentage points, respectively, compared with AC1 sample. They indicated excellent capacitive behavior.

Key words: activated carbon, removal of K⁺ process, oxidation-ultrasonic method, electrochemical properties