Effect of carboxymethyl cellulose on aqueous processing of LiFePO4 cathodes and their electrochemical performance

Aqueous-based LiFePO4 particulates were investigated with respect to their use in fabrication of lithium-ion battery cathode as a function of degree of substitution (DS) on carboxymethyl cellulose (CMC). The dispersion properties of LiFePO4 particulates were characterized using electroacoustic measurements, rheology, and microstructural observations at two different DS values on CMC. It was found that the LiFePO4 suspensions with lower DS had better long-term dispersing efficiency and more compact microstructure than those with higher DS. Furthermore, the electrodes with lower DS (141 mAh) exhibited a better electrochemical cycling performance than those with higher DS (134 mAh) after the same number of cycles. (C) 2008 The Electrochemical Society.