Rechargeable lithium batteries and beyond: Progress, challenges, and future directions

This issue contains assessments of battery performance involving complex, interrelated physical and chemical processes between electrode materials and electrolytes. Transformational changes in battery technologies are critically needed to enable the effective use of renewable energy sources such as solar and wind to allow for the expansion of hybrid electric vehicles (HEVs) to plug-in HEVs and pure-electric vehicles. For these applications, batteries must store more energy per unit volume and weight, and they must be capable of undergoing many thousands of charge-discharge cycles. The articles in this theme issue present details of several growing interest areas, including high-energy cathode and anode materials for rechargeable Li-ion batteries and challenges of Li metal as an anode material for Li batteries. They also address the recent progress in systems beyond Li ion, including Li-S and Li-air batteries, which represent possible next-generation batteries for electrical vehicles. One article reviews the recent understanding and new strategies and materials for rechargeable Mg batteries. The knowledge presented in these articles is anticipated to catalyze the design of new multifunctional materials that can be tailored to provide the optimal performance required for future electrical energy storage applications.