Effect of slurry preparation and dispersion on electrochemical performances of LiFePO4 composite electrode

A study is attempted on how the dispersion of solid ingredients in solvent affects the electrochemical performance of LiFePO4 composite electrode. The slurries comprising LiFePO4 powder, carbon black and polymeric binder in solvent NMP (N-methyl-2-pyrrolidone) are prepared by two different processes, and results in different dispersion qualities. With better dispersion, the surfactant (Triton-100) is added into slurry as dispersing agent, whereas no dispersing agent in the other sample. The former process leads to more uniform dispersion of solid ingredients as compared to the latter. In the composite electrode prepared from the former process, the LiFePO4 and carbon black particles are homogeneously distributed without obviously reunion. Indebted to this favourable feature, this electrode exhibits a better high C-rate electrochemical performance for cycling and capacity than those without the surfactant.