Improvement of rate capability by graphite foam anode for Li secondary batteries

The rate performances of Li batteries are severely influenced by the electrochemical properties of anode material. The graphite foams (GFms) is prepared by simple process from mesophase pitch (MP) precursor. The physical and electrochemical properties are investigated for Li secondary battery anode. The rate performances of GFms anode cell is more than 92% at the 30 C-rate compare to 1 C-rate current, which is very promising to the high power applications such as electric vehicles. For the quantitative analysis of rate capability improvement, the charge transfer resistance and diffusivity are measured by microelectrode system with single particle and galvanostatic intermittent titration technique (GITT). The diffusion coefficient of GFms is in the range of 3.2 × 10−12 - 2.0 × 10−9 cm2/s, which is 2 orders higher than that of commercialized graphite anodes.