Bacterial cellulose network based gel polymer electrolyte for quasi-solid-state sodium-ion battery

Quasi-solid-state sodium-ion batteries (QSSNIBs) are regarded as a wise choice that balances practicality with security. However, further improvements is hindered by low ionic conductivity at room temperature. Herein, based on bacterial cellulose network, a high-strength gel polymer electrolyte (BC-GPE) for QSSNIBs is developed. The interwoven structure with abundant 3D ion transport passageways of BC-GPE make it display both high-strength (tensile strength of 36 MPa and maximum strain of 31.23%) and the inhibitory of “sodium dendrite” and “dead sodium” (an outstanding average coulombic efficiency of 98.3% and 190 cycles at 0.5 mA/cm 2 and 1 mAh/cm 2 in the Na/BC-GPE/SS cell). Furthermore, due to the excellent electrochemical properties of BC-GPE and the compatibility with NASICON type cathode Na 3.5 Mn 0.5 V 1.5 (PO 4 ) 3 @C (NMVP@C), the QSSNIBs demonstrate high-rate performance and long cyclic life of 1250 cycles with a capacity decay rate of only 0.005%. All of these findings in this work can provide a novel insight for designing other high-strength GPEs and some new ideas for the potential applications of QSSNIBs in the near future.