Self‐Repairable Silicon Anodes Using a Multifunctional Binder for High‐Performance Lithium‐Ion Batteries

Abstract Despite of extremely high theoretical capacity of Si (3579 mAh g −1 ), Si anodes suffer from pulverization and delamination of the electrodes induced by large volume change during charge/discharge cycles. To address those issues, herein, self‐healable and highly stretchable multifunctional binders, polydioxythiophene:polyacrylic acid:phytic acid (PEDOT:PAA: PA, PDPP) that provide Si anodes with self‐healability and excellent structural integrity is designed. By utilizing the self‐healing binder, Si anodes self‐repair cracks and damages of Si anodes generated during cycling. For the first time, it is demonstrated that Si anodes autonomously self‐heal artificially created cracks in electrolytes under practical battery operating conditions. Consequently, this self‐healable Si anode can still deliver a reversible capacity of 2312 mAh g −1 after 100 cycles with remarkable initial Coulombic efficiency of 94%, which is superior to other reported Si anodes. Moreover, the self‐healing binder possesses enhanced Li‐ion diffusivity with additional electronic conductivity, providing excellent rate capability with a capacity of 2084 mAh g −1 at a very high C‐rate of 5 C.