Alkali Metal Anodes for Rechargeable Batteries

Currently, high-energy rechargeable batteries are being intensively pursued to meet the increasing energy requirements of our modern life and industrial society. Alkali metals are considered some of the most promising anodes for next-generation high-energy batteries because of their superior theoretical specific capacities and low reduction potentials. Here, we provide an overview of the recent development of alkali metal anodes. First, we highlight that their high reactivity, unstable solid electrolyte interphase, dendrite formation, and huge volume change bring great challenges for the safety and lifespan of alkali-metal-based batteries. Then, we summarize various advanced strategies—including the micro- and/or nanostructuring of alkali metals, introduction of stable hosts, structural modification of current collectors, construction of artificial anode-electrolyte interfaces, separator modification, and electrolyte optimization—to address these challenges. Lastly, we present the remaining challenges and possible research directions for further developments.