A Self-Healing Polymer Binder of Silicon-Based Anode with Enhanced Lithium-Ion Transport Performance

Abstract

A multi-functional binder was designed for silicon-based anode lithium-ion battery to alleviate the huge volume expansion of silicon anode during the process of charging and discharging, and to provide ion transport channels to improve the rate performance of electrodes to meet the needs of rapid charging and discharging. In this study, a binder PAA-TUEG which combined the mechanical properties of PAA, the fast self-healing ability provided by the zigzag hydrogen bond in TUEG, and the ion transport ability provided by the ether-oxygen group was synthesized. The effect of different proportion of TUEG binder on the electrochemical performance of the electrode was further investigated. The synthesized PAA-TUEG5% polymer material exhibits a tensilestrength of 0.8 MPa and a fracture elongation of 397%. The Si@PAA-TUEG5% electrode demonstrates reversible capacities of 3035, 2260, and 1249 mAh g−1 at 0.5, 1, and 2 C (1 C = 3500 mAh g−1), respectively. In extended cycling tests, the remaining capacities after 180 cycles at 0.5 and 1 C are 852 and 793 mAh g−1, respectively. This innovative binder, featuring both self-healing ability and enhanced ion transport through dynamic reversible hydrogen bond and ionic bond, presents a promising design concept for the next generation of high-energy-density lithium-ion batteries.