Understanding the Electrochemical Performance of Spongy C-F Derivative Chains as an Effective Anion Trapping Composite Matrix for Li-Ion Batteries

Recently, the rapid growth of Li-ion battery (LIB) technologies requires the exploit of highly porous, thermally, and electrochemically stable composite polymer electrolyte (CPE) membranes. Herein, a novel spongy asymmetric composite matrix composed of poly(vinylidene fluoride cohexafluoropropylene), cellulose, and boron nitride was designed via a spinning cum immersion precipitation route. Notably, the fabricated PCBN-CPE membrane displays a high surface porosity, good electrolyte uptake, better mechanical stability, and excellent thermal stability. The fabricated membrane, assembled with a LiFePO4 parallel to Li electrochemical cell, exhibits splendid cycling stability, with a primary specific discharge capacity of 154.1 mAh g(-1) and a capacity retention of 73.8% after 250 cycles at 0.2 C. In addition, the composite polymer electrolyte renders an excellent Li-ion transference number (0.86) at room temperature. Interestingly, the density functional results elucidate that the existence of boron nitrides on the porous matrix can effectively trap anions (PF6-) and, thereby, reduce the growth of Li dendrites. Therefore, the present work affords a fabulous approach for high-performance Li-ion battery (LIB) application.