Protection of lithium metal anodes: A comprehensive review

Lithium metal batteries (LMBs) have emerged as a transformative solution for next-generation energy storage systems, offering exceptional theoretical energy densities. Nevertheless, the practical implementation of lithium metal anodes (LMA) faces critical challenges, including dendrite formation, volume expansion, lithium deactivation, and high reductivity. These unresolved issues manifest in compromised safety profiles, constrained cycle durability, and suboptimal electrochemical performance. This comprehensive review systematically examines contemporary progress in LMA protection strategies, categorized into three principal approaches: Surface Modification Techniques designed to optimize the chemical homogeneity and nucleation dynamics of lithium deposition through tailored surface architectures. Interfacial Engineering strategies targeting enhanced charge transfer kinetics and robust solid electrolyte interphase (SEI) formation via interfacial modulation. New lithium anode materials, enhancing lithium metal stability and compatibility through alloy materials. These concerted efforts collectively address fundamental aspects of lithium-ion flux regulation and SEI stabilization mechanisms. Beyond critically assessing current scientific bottlenecks, this analysis maps future research trajectories, emphasizing multi-dimensional solutions. Particular focus is directed towards the synergistic integration of emerging nanomaterials, three-dimensional electrode configurations, and novel materials to accelerate the realization of commercially viable, high-safety LMBs. The discourse culminates in a balanced perspective on persistent technical hurdles and promising investigative pathways, highlighting the pivotal role of intelligent material design paradigms and machine learning-enabled optimization in advancing next-generation LMBs technologies.