Gel polymer electrolyte with high performances based on pure natural polymer matrix of potato starch composite lignocellulose

Highlights: •Starch composite lignocellulose for gel polymer electrolyte (GPE) is inspected. •The composite membrane possesses more than 6 times enhanced in tensile strength. •The GPE show high lithium ion transference number (0.79). •The prepared GPE with outstanding comprehensive performances is biodegradable. -- Abstract: A kind of gel polymer electrolyte (GPE) based on natural composite polymers matrix of lignocellulose (LC) and potato starch with higher comprehensive performance is prepared. This study reveals that when the content of potato starch is 5 wt.%, the composite membrane presents 6 times tensile strength of pure LC membrane and high electrolyte uptake of 194%. Meantime, the ionic conductivity of 1.27 mS cm⁻¹, lithium ion transference number of 0.79, wide electrochemical window and good affinity with electrodes for the as-prepared GPEs can be obtained. In addition, the Li/GPE/LiFePO₄ cells display excellent initial discharge capacity, rate and cycling performances. Therefore, the high performance, low cost and biodegradable GPE with the optimized material proportion developed in this work for application in lithium ion batteries (LIBs).