RETRACTED: Cross-Linked Sodium Alginate–Sodium Borate Hybrid Binders for High-Capacity Silicon Anodes in Lithium-Ion Batteries
Jianbin Li, Xianchao Hu, Hongshun Zhao, Yurong Ren, Xiaobing Huang
Abstract
Silicon is considered one of the most promising next-generation anode materials for lithium-ion batteries. It has the advantages of high theoretical specific capacity (4200 mAh·g–1), which is 10 times larger than that of a commercial graphite anode (372 mAh·g–1). However, there are some problems such as the pulverization of the electrode and an unstable solid electrolyte interphase (SEI) layer aroused by the huge bulk effect (>300%) of Si during the repeated lithiation/delithiation process. A binder plays a vital role in the conventional lithium-ion batteries that can effectively relieve the bulk expansion stress of a silicon anode. In this work, the inorganic cross-linker sodium borate (SB) and the commonly used binder sodium alginate (SA) were condensed through an esterification reaction and the reaction product was marked as SA–SB. It is found that the mechanical robustness and the peel strength of SA–SB are improved after cross-linking, which is conducive to maintaining the structural stability of the silicon anode in long cycle life. In consequence, the capacity retention of the silicon anode using the SA–SB binder (64.1%) is higher than that of SA (50.6%) after 100 cycles at 0.2 A·g–1.