A renewable gel polymer electrolyte based on the different sized carboxylated cellulose with satisfactory comprehensive performance for rechargeable lithium ion battery

Gel polymer electrolyte (GPE) comprising the merits of liquid electrolyte (LE) and solid state electrolyte (SSE) has attracted soaring attention. Herein, we develop a GPE with good comprehensive performance by means of mixing the micro carboxylated cellulose fibril (MCCF) and nano carboxylated cellulose fibril (NCCF) in different proportions. In this composite structure, MCCF forms the skeleton of the host membrane of GPE and provides aplenty pores. While NCCF reinforces the connections of the micron cellulose filaments, enhancing the mechanical properties of the membrane. Obtained from the experimental results, the GPE containing 1%wt nano cellulose exhibits a high tensile strength of 40.1 MPa, a good ionic conductivity of 1.84 mS cm −1 at 25 °C and a stable thermal performance up to 220 °C. Simultaneously, the NCM523//Li half cell assembled with this GPE shows a moderate cyclic performance at the ambient temperature of 25 °C. Moreover, such cellulose based GPE is renewable and biodegradable, which can contribute to the environmental protection-oriented development of lithium ion battery industry. • The Carboxylated cellulose prepared via TEMPO-oxidization is adopted as host material of GPE for LIB. • The GPE based on the multi-sized carboxylated cellulose possesses satisfactory comprehensive performance. • This work can provide a direction for the development of renewable and biodegradable GPE.