Durable and Damageless Supramolecular Binder for Fast, Stable, and Sustainable Si-Based Anodes
Zhu Liu, Yongming Wang, Guoquan Liu, Xinyang Yue, Zhangqin Shi, Yi‐Hong Tan, Jun Zhao, Lei Yu, Xuzhou Yan, Zheng Liang
Abstract
Mechanical fatigue of the binders during the repeated volume change of Si-based anodes induces binder network collapse, resulting in lithium-ion batteries (LIBs) failing prematurely. Herein, we designed a damageless polymer binder with a mechanically interlocked network utilizing [ a n]daisy chains ( DC MIN) and poly(acrylic acid) (PAA) to improve the structural cohesion of the Si-based anode. This DC MIN@PAA binder exhibits robust mechanical properties, high elasticity, and excellent adhesion. More importantly, the recognition between the dialkylammonium salt decorated on the thread component and the ether group of benzo-24-crown-8 provides efficacy for the DC MIN@PAA binder in quickly dissipating energy and reducing damage accumulation. Therefore, with the DC MIN@PAA binder, the pure-Si anode showcases high retention over 1050 cycles at 1 C and a fast rate response (5 C). The DC MIN@PAA binder also improves the cycling stability of the homemade pouch cell using a pure-Si anode. In addition, the water-soluble DC MIN@PAA binder, capable of quick release and separation, could facilitate recycling of the end-of-life anode, enhancing the sustainability of the battery. This work highlights the indispensability of energy dissipation with the consideration of a binder and provides a viable path forward to stabilize Si-based anodes suffering from volume change-induced stress accumulation.