Insights from Li and Zn systems for advancing Mg and Ca metal batteries

The inherent limitations of lithium (Li)-ion batteries have sparked interest in exploring alternative technologies, especially those relying on metallic anodes: monovalent Li and divalent zinc (Zn), magnesium (Mg), and calcium (Ca) metals. In particular, Mg and Ca metal batteries offer significant advantages based on the natural abundance of their raw materials and high energy-storage capabilities resulting from the bivalency of the carrier ions. Yet, these battery systems are far from commercialization, and the lack of reliable electrolytes constitutes a primary concern. The formation of ion-insulating passivation layers on these metallic anodes and their inferior desolvation kinetics have long been recognized as formidable hurdles in the way of optimizing the electrolyte composition. These impediments call for innovative strategies in electrolyte engineering and an extensive analysis o…