Anode-Free Batteries: Pioneering Energy Storage Revolution

Anode-free batteries (AFBs) represent a transformative approach in energy storage technologies, eliminating the anode to achieve remarkable improvements in energy density, safety, and manufacturing simplicity. This review provides a comprehensive analysis of the fundamental phenomena governing the operation of AFBs during metal plating and stripping, including nucleation and growth, dendrite formation, dead lithium formation and regeneration mechanisms, morphological evolution, and electrolyte decomposition. The challenges associated with AFBs are critically examined, alongside various designed innovative strategies. Expanding the discussion beyond lithium, this review explores advancements in anode-free sulfur, sodium, potassium, zinc, magnesium, aluminum, and all-solid-state batteries, highlighting the unique challenges and solutions tailored to each system. Critical parameters influencing performance, including Coulombic efficiency, electrolyte-to-cathode ratio, and cycling protocols, are analyzed to provide insights into optimizing these systems. Furthermore, the potential of AFBs as a platform for probing interfacial phenomena is emphasized, with applications in visualizing metal deposition, quantifying dead metal formation, and rapid screening of electrolytes. The review concludes with a perspective on future research directions aimed at addressing current limitations and accelerating the practical deployment of AFBs. By bridging fundamental understanding and innovative design, this work positions AFBs as a pivotal technology for the next generation of high-performance energy storage systems.