Organic ionic plastic crystals (OIPCs) are the crystals of electrolytes with a long-range translational order. The rotational modes of ions in OIPCs are, however, activated even in solid phases such...

Organic ionic plastic crystals (OIPCs) are one of promising solid‐state electrolytes (SSEs) for all‐solid‐state batteries. OIPCs consist of organic ions that form crystalline solid phases. It is a challenging but critical task in the development of SSEs to improve the ion conductivity of lithium ions in such crystalline solid phases. We discuss our recent simulation studies on the transport mechanism of ions in OIPCs and show that the dynamic heterogeneity should be a key to the transport mechanism. We aim to show that both translational and rotational dynamic heterogeneities should play an important role in understanding the ionic conductivity in SSEs. We found from our simulations that the introduction of dopants and defects into OIPCs facilitated both the dynamic heterogeneity and the ion conductivity significantly. We also found that the polarizability of matrix organic ions could contribute to the rotational and conformational relaxations of organic ions in OIPCs.

Organic ionic plastic crystals (OIPCs) consist of molecular ions of which interactions are strong enough to maintain crystalline order but are weak enough to allow the rotations of the molecular...