Effect of overcharge on Li(Ni0.5Mn0.3Co0.2)O2/Graphite cells–effect of binder

Cells based on NMC/graphite, containing styrene-butadiene rubber/carboxymethylcellulose binder in the anodes and pVdF latex/carboxymethylcellulose in the cathodes, were systematically overcharged to 100, 120, 140, 160, 180, 250% and 270% state-of-charge. The impact of the binder was characterized by elemental analysis, SEM, and HPLC. These results were compared to similar cells just using the poly (vinylidene difluoride) binder. Not only did the binder impact the rate of transition metal transport from the cathode to the anode, it also had a marked effect on the microstructure and composition of the materials on the anode surface. •LFP/Graphite cells made with pVdF or CMC binders were overcharged to 100–250% SOC.•Marked microstructural changes in the anode with SOC were seen in those with CMC.•The number of organics in the SEI was sensitive to binder.