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

• Published in: Solid state ionics 2019-12, Vol.343, p.115070, Article 115070
• Main Authors: Song, Jinhua, Feng, Zhenhe, Wang, Yong, Zhou, Xinbin, Zhang, Xinghao, Wang, Ke, Xie, Jingying
• Format: Article
• Language: English
• Subjects: Anode effect; Binder; Electrodes; Engineering; High energy density; Lithium; Lithium hydroxides; Lithium ion battery; Lithium ions; PAA; Silicon; Surface cracks; Surface stability
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2019.115070

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|SiOx/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. •Most suitable process based on PAA binder for high energy density pouch cells•Remarkable rate and cycle performance obtained by Li-PAA binder with lack amount of binders and conductive additives•Suppressed volume expansion of silicon was the main reason for favorable cyclability.