Investigation of Li~+ as additive to (NH_4)_2SO_4 electrolyte for supercapacitor

To improve the capacitance, Li+ as additive was added to (NH4)2SO4 electrolyte for activated carbon and MnO2/ activated carbon hybrid supercapacitor. The test results show that when 0.37 mol/L Li2CO3 is added into 2 mol/L (NH4)2SO4 electrolyte, the specific capacitance is highest. The function of additive to hybrid supercapacitor is more than that to double layer capacitor. The specific capacitance of hybrid supercapacitor is higher than that of without additive by 77 %, and after 2 000 cycles, the specific capacitance is 30 F/g and reduces by 2.9 %.