Organic ionic plastic crystals as solid-state electrolytes

The development of safe and reliable energy conversion and storage technologies is an urgent global challenge central to mitigating our dependence on fossil fuels. Key to many emerging electrochemical technologies is the need for a safe and stable electrolyte that enables high device efficiency. Organic ionic plastic crystals (OIPC)are an emerging class of solid-state electrolytes with significant advantages over conventional materials, including plasticity, nonflammability, and high ionic conductivity. Recent advances in this evolving field include increasingly efficient lithium-ion batteries and dye-sensitized solar cells, and the first application of OIPCs in sodium-ion batteries. In this review, we highlight these advances and discuss recent fundamental developments such as structure–property relationships and conduction mechanisms in both protic and aprotic OIPCs.