Research progress of polymer composite system in solid electrolyte

Because of its light weight, flexibility, and good contact with electrode, solid polymer electrolyte (SPE) has become a potential material for the development of electrochemical devices with high energy density, high safety and high flexibility, and has been paid extensive attention in recent years. However, defects such as low ionic conductivity and poor mechanical properties have also become the problems that limit its further commercialization. It is possible to solve these problems by forming a composite system of polymers by means of crosslinking, blending, copolymerization, etc. Therefore, in this paper, the mechanism of ionic conductivity in polymers was briefly introduced in order to explain the strategies to solve the above problems from the point of principle. Then, the applications and modification strategies of a variety of polymer-based composite electrolytes in electrochemical devices in recent years were reviewed. Finally, the problems of basic research and practical application faced currently by the composite SPEs were discussed and the solutions to these problems were given. It is hoped that this review can provide ideas for the design and preparation of future composite SPEs