High-voltage polymer electrolytes: Challenges and progress

In recent years, research and commercial effort has been focused on developing high-performance polymer electrolytes (PEs) to create high-energy lithium metal batteries (LMBs). However, increasing battery energy density comes at the expense of continual PE disintegration at high voltage and worsening of the electrolyte/ electrode contact. In this review, the merits and drawbacks of various functional units and polymer manufacturing methods are explored, and they are employed in composite solid electrolytes to rectify the inherent faults of inorganic electrolytes and raise the energy density of LMBs. The electrochemical testing techniques of PEs are then discussed, and novel testing methods to rigorously test PEs to produce the most realistic findings are offered. It is demonstrated that the design of high-voltage electrolytes may begin with the structure of the polymer matrix, molecular interactions within the electrolyte, and interface architecture between the electrode and electrolyte. Finally, the future of high-energy LMBs is examined, and some present development challenges are identified, with the hope that they will be resolved soon.