Mechanistic insights and materials strategies for dendrite-free metal anodes in alkali and zinc batteries

Advanced battery technologies have gained significant interest because of the high-energy-density demands of proliferated electronic devices and extensive energy storage systems. Introducing metals such as Lithium (Li), Sodium (Na), Potassium (K), and Zinc (Zn) to high-capacity, high-voltage cathodes offers a promising pathway toward conquering conventional low-capacity anode materials such as graphite and silicon carbon. However, several critical challenges are associated with metal batteries, including the high reactivity of anodes, dendritic growth, and associated safety hazards; most of these problems originate with dendrites. Dendrite formation increases the effective surface area of the metal anode, disrupting the solid electrolyte interphase (SEI) and accelerating electrolyte consumption, thus causing capacity degradation and short circuits, which pose a safety risk. This review investigates the core mechanisms underlying dendrite formation, their effects on battery efficiency, and the factors driving their growth, including temperature, current density, and interfacial behavior. Furthermore, it explores recent innovations in mitigating dendrite growth, focusing on electrolyte formulation, electrode optimization, and interphase engineering across various metal battery systems. Finally, the review offers perspectives to address dendrite-related challenges, advancing safer and more reliable battery technologies.