Stable and conductive carbon networks enabling high-performance silicon anodes for lithium-ion batteries

Abstract

Many strategies have been developed to improve the Li-ion storage performance of silicon (Si)-based anodes. Unfortunately, production and application of the Si-based anodes are still severely impeded by high cost, complex synthesis and poor practical performance. Herein, we demonstrate a cost-effective strategy for large-scale production of Si-based anodes by pyrolyzing economical gelatin and ball-milled micron-sized Si particles. During the pyrolysis process, the good water solubility and film-forming property of gelatin enable it to form continuous carbon networks with enhanced dual-interfacial bonding between Si particles and current collectors. As a result, the obtained Si anode exhibits an integrated dense structure with ultrahigh Si content and excellent mechanical flexibility. The BMSi@GC anode delivers a high initial coulombic efficiency (88.2%) with high capacities (2,738 mAh g −1 , 2,157 mAh cm −3 , and 2.74 mAh cm −2 ). Moreover, a BMSi@GC//LiCoO 2 pouch cell shows high energy densities (537 Wh kg −1 and 585.1 Wh L −1 ) with good cycling performance. • A low-cost strategy for the preparation of Si anode is proposed • Stable and conductive carbon networks enable good anode performance • In situ characterization reveals the modification mechanism • A full cell based on the Si anode exhibits high energy density Yang et al. propose a cost-effective strategy for large-scale and continuous production of Si-based anodes by using economical micron-sized Si and gelatin as precursors. The gelatin-derived carbon networks with dual-interfacial interactions endow the Si anode with high performance for practical use in Li-ion batteries.