Short communication

A novel and efficient water-based composite binder for LiCoO2 cathodes in lithium-ion batteries

The dispersion, adhesion strength, electrical, and electrochemical properties of LiCoO ₂ cathodes in lithium-ion batteries with the addition of a new composite binder composed of two acrylic emulsions, poly(butyl acrylate)-based (PBA) and polyacrylonitrile-based (PA) latex in a ratio of 3:7, were evaluated. PBA binder has a low-glass transition temperature of 10°C, which can improve the flexibility of the electrode. This new composite binder has a very good binding ability as same as the typical organic solvent-based binder, poly(vinylidene fluoride). The dispersions of the water-based cathode slurries with the composite binder were measured by analyzing the viscosity and sedimentation behaviors. The results show that the new composite binder can well disperse the LiCoO ₂ . Moreover, using the new composite binder could greatly improve the rate capabilities and the cycle stability of water-based LiCoO ₂ cathodes.