Suppressed volume variation of optimized SiO_x/C anodes with PAA-based binders for advanced lithium-ion pouch cells

The binder plays an important role in the aspect of improving cycle performance of silicon anode electrodes. Although a series of new binders have been developed by researchers, the feasibility of engineering application of these binders is a significant challenge. To address this problem, three kinds of PAA-based binders which were prepared by different mixing process were discussed. It was indicated that using Li-PAA binder independently, which were neutralized by lithium hydroxide solution, could buffer the volume expansion of silicon, decrease the surface cracks and enhance the crystal stability of anodes, effectively. The obtained NCA|SiO_x/C pouch cell with the single-sided areal density of anode electrode reached 11.5 mg/cm² showed remarkable rate performance with 90.9% capacity retention (vs. the capacity at 0.1C) at 1C rate and favorable cyclability with 90.8% capacity retention after 100 cycles. All these results provided convincing evidence to construct cells over 300 Wh/kg with the further design of capacity comes up to 20 Ah.