A new method to determine the solid diffusion coefficient of Li~+ in anode materials was introduced, which was called capacity intermittent titration technique (CITT). The solid diffusion coefficient of Li~+ within LiCoO_2 was determined by CITT. The variation of solid diffusion coefficient of Li~+ within LiCoO_2 under different voltages and different cycling number was studied. CITT results show that value of Li~+ solid diffusion coefficient of LiCoO_2 is about 10~(-12)cm~2/s. The value of solid...