Opening and Constructing Stable Lithium‐ion Channels within Polymer Electrolytes

Abstract

Lithium‐ion batteries play an integral role in various aspects of daily life, yet there is a pressing need to enhance their safety and cycling stability. In this study, we have successfully developed a highly secure and flexible solid‐state polymer electrolyte (SPE) through the in‐situ polymerization of allyl acetoacetate (AAA) monomers. This SPE constructed an efficient Li+ transport channel inside and effectively improved the solid‐solid interface contact of solid‐state batteries to reduce interfacial impedance. Furthermore, it exhibited excellent thermal stability, an ionic conductivity of 3.82×10‐4 S cm‐1 at room temperature (RT), and a Li+ transport number (tLi+) of 0.66. The numerous oxygen vacancies on layered inorganic SiO2 created an excellent environment for TFSI‐ immobilization. Free Li+ migrated rapidly at the C=O equivalence site with the poly(allyl acetoacetate) (PAAA) matrix. Consequently, when cycled at 0.5 C and RT, it displayed an initial discharge specific capacity of 140.6 mAh g‐1 with a discharge specific capacity retention rate of 70% even after 500 cycles. Similarly, when cycled at a higher rate of 5 C, it demonstrated an initial discharge specific capacity of 132.3 mAh g‐1 while maintaining excellent cycling stability.