Abstract:

The dispersible uniformity of cathode slurry of Li-ion battery has significant influence on the performance of bat-tery.Fine dispersible uniformity of cathode slurry of Li-ion battery relied on the adequate knowledge of rheological properties of slurry.Cathode slurry was prepared by using two commercial PVDF with different structure as binder,Li（Ni,Mn,Co）O₂ as active material,carbon black as conducting additive（SP） and N-methy-2-pyrrolidone as solvent.The influence of PVDF structure on the rheological properties of cathode slurry of battery was analyzed using rotational rheometer.Results showed that,for steady shear,the slurry with branched PVDF as binder had higher zero-shear-rate viscosity and lower yield point than slurry with linear PVDF as binder,which meant slurry had higher anti-sedimentation and better fluidity.For oscillatory shear,slurry with linear PVDF as binder was prone to yield flow.SEM result showed that branched PVDF could bond with SP and active material to form a space conductive network,and the component distribution is more uniform.The research provided basis for technological optimization of storing and dispersion of Li-ion battery slurry.

Key words: cathode slurry, PVDF, Li-ion battery, rheological property