Developing Single-Ion Conductor Polymer Electrolytes for Rechargeable Magnesium Batteries: A Concept

Single-ion conductor polymer electrolytes (SICPEs), which exhibit a transference number (t_Mg2+) approaching unity, offer significant advantages for rechargeable magnesium batteries (RMBs). These advantages include reducing parasitic side reactions from salt anions, promoting the uniform deposition of Mg²⁺ during cycling, and enhancing the overall performance and stability of full cells. Despite these promising benefits, research on SICPEs for RMBs is still in its early stages, with many challenges remaining to be addressed. In this paper, we summarize the advantages of SICPEs and present innovative and feasible design strategies for their development in RMBs. By highlighting recent advancements, existing gaps, and our proposed strategies, we aim to stimulate further research and innovation in the field, ultimately enabling the realization of safer, more efficient RMBs with improved cycling stability and higher energy density.