Facile synthesis of microporous carbon for supercapacitors with a LiNO3 electrolyte

A facile method for the direct synthesis of interconnected microporous carbon via carbonization of potassium acid phthalate in inert atmosphere is reported. The as-obtained microporous carbon exhibited a high specific surface area (1118 m2 g−1) and 67% of the pore volume was attributed to microporosity, which are ideal for electrodes of supercapacitors. LiNO3 electrolytes of different concentrations were selected according to their corresponding conductivities to evaluate the use of aqueous electrolytes in supercapacitors. The electrochemical performance of the interconnected microporous carbon in 6 M KOH and 1-5 M LiNO3 electrolytes was investigated. The results showed that the microporous carbon could deliver optimal electrochemical properties as an electrode material for supercapacitors. In addition, the electrochemical investigation showed that the microporous carbon exhibited a broad voltage operational window in 3 M LiNO3 electrolyte. Furthermore, 86.2% of the capacitance was retained even after 5000 cycles at 1.6 V.