Electrolytes for target ion transport

A zwitterionic plastic crystal (ZIPC) compound in the form of a non-polymeric molecule comprising:

• at least one positively charged functional group carrying at least one positive charge, and
• at least one negatively functional group carrying at least one negative charge, wherein
• the positively charged functional groups and the negatively charged functional groups are covalently tethered together in the molecule, and the net charge of the zwitterionic compound is zero, and wherein the compound exhibits molecular disorder in the solid state, wherein the compound exhibits two or more of the following:
• thermal phase behaviour which includes one or more solid-solid phase transitions before melting;
• in the solid state one or more NMR linewidths of 20 KHz or less;
• and
• a morphology including slip and glide planes on SEM analysis.