Stable operation of SiO anodes enabled by a multifunctional molecular crosslinker

Abstract

SiO anodes are promising for energy-dense lithium-ion batteries, however, they suffer from short cycle life caused by large volume change (∼200%) and low initial Coulomb efficiency (ICE). Herein, we report a conceptual strategy to boost the electrochemical performance of SiO by enhancing the interaction between binders and conductive additives via a molecular crosslinker with both pyrene ring and adamantyl group (AdPy). Benefiting from the inclusion interaction between beta-cyclodextrin polymers (βCDp) and AdPy as well as the π-π interaction between single-walled carbon nanotube (SWCNT) and AdPy, a robustly conductive and adhesive network is constructed for maintaining integral electrode structure and robust conductive network during charge/discharge cycles. The resultant SiO electrode with SWCNT/AdPy-βCDp networks achieves larger initial capacity, higher ICE and better cycle stability than those of SiO electrode with SWCNT/βCDp complex, indicating the key role of AdPy crosslinker in enhancing electrochemical performance. Experimental results suggest that the interaction between binders and conductive additives can effectively alleviate stress generated from SiO volume changes during cycling. This work provides a promising platform to construct dynamic cross-linking conductive and adhesive network for boosting the lithium storage performance of high-capacity electrode materials.