A Cellulose/Polyethylene Oxide Gel Polymer Electrolyte with Enhanced Mechanical Strength and High Ionic Conductivity for Lithium‐Ion Batteries

Abstract Polyethylene oxide (PEO) gel polymer electrolyte (GPE) is a promising electrolyte for rechargeable lithium‐ion batteries (LIBs). However, they still suffer from weak mechanical properties and low ionic conductivity. Herein, a novel hybrid GPE with enhanced mechanical properties and superior ionic conductivity is developed by introducing regenerated cellulose (RC) into PEO. Benefiting from the 3D porous interconnected network structure of cellulose aerogels, the obtained PEO‐RC GPEs exhibit improved mechanical strength (up to 40 MPa), increased electrolyte absorption ability, excellent ionic conductivity (4.34 × 10−3 S cm−1), and remarkable Li‐ion transfer number (0.60). As a result, a rechargeable LIB assembled with LiFePO4/GPEs/Li demonstrates a high initial discharge capacity of 149.3 mAh g−1 at 0.2 C and an impressive capacity of 141.3 mAh g−1 (94.6% capacity retention) after 100 cycles. This work provides a new route to the design and synthesis of novel GPEs toward next‐generation safe rechargeable LIBs.