Materials design for high-energy-density anode-free batteries

With the merits of high energy density, cost effectiveness, high safety, and simple manufacturing, anode-free batteries (AFBs) are emerging as promising alternatives for next-generation energy storage devices. Nevertheless, the development of AFBs is restricted by rampant dendrite growth, large volume expansion, undesirable side reactions, and unstable solid electrolyte interphase layers. Summarizing the materials design principles of current collectors, electrolytes, and cathodes is crucial for the improvement of AFBs. Herein, the latest progress of AFBs is comprehensively reviewed. First, the fundamental principles of AFBs, such as configurations, working mechanisms, advantages, scientific challenges, etc., are introduced. Subsequently, the materials design strategies of current collectors, electrolytes, and cathodes to overcome these challenges are summarized in detail. Finally, a summary and perspectives on the future possible directions of AFBs toward practical applications are proposed.