A mechanically robust, biodegradable and high performance cellulose gel membrane as gel polymer electrolyte of lithium-ion battery

Biodegradable matrixes obtained from natural renewable resources have received increasing attention in the field of gel polymer electrolyte for lithium ion batteries. However, the inferior mechanical property, low uptake ability for liquid electrolytes and the poor lithium ion transference are the obvious drawbacks nowadays. Here, a mechanically robust and environmentally friendly cellulose gel membrane is prepared by the facile solution casting and one-step crosslinking method. This study showed that the GPE based on this cellulose membrane with 5% crosslinker not only possessed good tensile fracture strength of 14.61 MPa, but also presented remarkable electrochemical performance, including high electrolyte uptake of 540%, high ionic conductivity of 6.34 × 10−3 S cm−1, high lithium ion transference number of 0.82 at room temperature, excellent compatibility with lithium electrode and good electrochemical stability. In addition, the assembled cell showed a discharge capacity of 145 mA h g−1 after first cycle at 0.2 C-rate and a high capacity retention of 90% after 50 cycles. We anticipate that this natural polymer membrane will be applied as a high safety, low cost and environmental friendly GPE of lithium-ion batteries.