Effect of composite conductive agent consisting of graphene and Super-P carbon black on the performance of LiNi_0.5Co_0.2Mn_0.3O₂ lithium-ion battery

This paper, taking graphene (Gen), conductive carbon black Super-P (SP) and a composite conductive agent consisting of graphene and conductive carbon black (Gen/SP) as the research object, made pouch batteries using a single conductive agent (SP or Gen) and composite conductive agent Gen/SP under different mass ratios, respectively. The cathode material for pouch batteries is LiNi_0.5Co_0.2Mn_0.3O₂, and the preparation process includes preparing slurry, coating, winding, etc. Such testing methods as XRD, SEM and constant-current charging/discharging were applied to study the composites between the conductive agent and positive electrode particles and their effect on the performance of batteries. According to the results, batteries with 1.0% composite conductive agent presented the best performance, and the worst performance was with 0.5% composite conductive agent. Batteries with different contents of composite conductive agent showed better performance, and the pouch batteries prepared with a 1.0% composite conductive agent Gen/SP(5∶5, (w/w)) had the best performance. The specific capacity of initial discharge at 0.1 C was 160.38 mA·h/g, while the capacity retention rate was 97.3% after 100 cycles at 0.5 C.