Toward high lithium conduction in solid polymer and polymer-ceramic batteries

High-energy-density batteries use lithium electrodes because they provide the highest theoretical capacity and widest electrochemical potential window of all the possible anodes for rechargeable lithium batteries. However, adoption of metallic lithium leads to safety problems and low cycling performance due to the reactivity of lithium with standard liquid electrolytes (LEs). Solid electrolytes (SEs) are a promising solution to replace LEs due to their high thermal and chemical stability. They also possess numerous other advantages such as light-weight, flexibility, low-cost and a high operating window voltage. The aim of this review is to present a summary of recent advances in polymer and inorganic SEs for all-solid lithium metal batteries (LMBs). We will discuss the replacement of polyethylene oxide (PEO) and the crucial parameters for achieving a suitable combination of polymer matrix with inorganic ceramic fillers to obtain viable SE composites for high-voltage and high-capacity cell.