A Highly Efficient Silicone-Modified Polyamide Acid Binder for Silicon-Based Anode in Lithium-Ion Batteries

Silicon (Si) exhibits an excellent specific capacity and emerging application potential as anode material of lithium-ion batteries. However, Si anodes usually generate the huge volume expansion and the instability of the solid electrolyte interface, leading to performance degradation. Herein, a silicone-modified partially imidized polyamide acid (S-PA) is successfully synthesized, which shows excellent performances as the binder of a silicon-based electrode in lithium-ion batteries. The S-PA anodes exhibit high initial Coulombic efficiencies of above 87% and maintain over 98% in the following cyclic tests. At a current of 0.5 C, the initial discharge capacity of the S-PA-based electrode is as high as 2736 mAh g–1 and remains at about 2295 mAh g–1 over 200 cycles. The abundant chemical bonds in the S-PA binder contribute to the improvement of the interactions with silicon nanoparticles, maintain the electrode structural integrity, and facilitate the Li-ion diffusion during cycling. The results show that S-PA is a promising type of binder for silicon-based anodes as compared with commonly adopted PAA and PVDF.