Water-Soluble Polyamide Acid Binder with Fast Li+ Transfer Kinetics for Silicon Suboxide Anodes in Lithium-Ion Batteries

Silicon suboxide(SiO (x) ) anodes haveattracted considerable attention owing to their excellent cyclingperformance and rate capability compared to silicon (Si) anodes. However,SiO (x) anodes suffer from high volume expansionsimilar to Si anodes, which has been a challenge in developing suitablecommercial binders. In this study, a water-soluble polyamide acid(WS-PAA) binder with ionic bonds was synthesized. The amide bondsinherent in the WS-PAA binder form a stable hydrogen bond with theSiO (x) anode and provide sufficient mechanicalstrength for the prepared electrodes. In addition, the ionic bondsintroduced by triethylamine (TEA) induce water solubility and newLi(+) transport channels to the binder, achieving enhancedelectrochemical properties for the resulting SiO (x) electrodes, such as cycling and rate capability. The SiO (x) anode with the WS-PAA binder exhibited a highinitial capacity of 1004.7 mAh & BULL;g(-1) at a currentdensity of 0.8 A & BULL;g(-1) and a capacity retentionof 84.9% after 200 cycles. Therefore, WS-PAA is a promising binderfor SiO (x) anodes compared with CMC andSA.

Automated summary

A water-soluble polyamide acid (WS-PAA) binder with ionic bonds was synthesized as a promising binder for SiO(x) anodes. The WS-PAA binder formed stable hydrogen bonds with the SiO(x) anode and provided sufficient mechanical strength for the electrodes. The introduction of ionic bonds by triethylamine (TEA) improved water solubility and Li(+) transport channels, enhancing the electrochemical properties of SiO(x) electrodes.