Sodium-Ion Batteries

13Solid‐State and Gel Electrolytes for Sodium‐Ion Batteries

13.1 Introduction

Liquid electrolyte used in traditional secondary battery systems has good ion transport capacity and excellent electrochemical performance. However, liquid electrolyte is not perfect with several disadvantages. First, the thermal stability and electrochemical stability of liquid electrolyte are not good enough, especially at elevated temperatures or against Na metal anode or high‐potential cathode. Second, liquid electrolyte suffers from concentration polarization, due to low Na⁺ transport number. Third, liquid electrolyte poses safety risks due to its flammability. Lastly, batteries with liquid electrolyte are easy to leak and gas, which also leads to safety problems. ...