Durable and Damageless Supramolecular Binder for Fast, Stable, and Sustainable Si-Based Anodes

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 [an]daisy chains (DCMIN) and poly(acrylic acid) (PAA) to improve the structural cohesion of the Si-based anode. This DCMIN@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 DCMIN@PAA binder in quickly dissipating energy and reducing damage accumulation. Therefore, with the DCMIN@PAA binder, the pure-Si anode showcases high retention over 1050 cycles at 1 C and a fast rate response (5 C). The DCMIN@PAA binder also improves the cycling stability of the homemade pouch cell using a pure-Si anode. In addition, the water-soluble DCMIN@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.