The Polymer Society of Korea

Abstract

Silicon (Si) is a promising anode for lithium-ion batteries (LIBs) due to its high theoretical capacity; however, severe volume changes during lithiation/delithiation lead to particle pulverization, repeated SEI rupture/reformation, and rapid capacity fade. Because ex situ characterization provides post-mortem snapshots, it often misses the nanoscale evolution of deformation and interfacial instability. Here, we develop a host–guest supramolecular self-healing binder and use in situ TEM to visualize lithiation-induced Si expansion and damage evolution in real time. Reversible bonding dissipates stress and enables autonomous crack healing under repeated swelling/shrinkage. In situ TEM shows that the supramolecular binder accommodates nanoscale deformation, preserves electrode integrity, and improves electrochemical stability and cycling retention. These results highlight supramolecular self-healing binders as an effective strategy for durable, high-capacity Si anodes.