Structural Design and Advanced Diagnostics of Lithium Metal Anodes for High-Energy-Density Batteries

Lithium metal anodes (LMAs) are pivotal for next-generation high-energy-density batteries but are plagued by dendritic growth and interfacial instability. Moving beyond the extensively reviewed domain of electrolyte and interface engineering, this review offers a dedicated focus on two pivotal and interconnected frontiers: (1) the rational structural design of anodes, encompassing 3D lithiophilic hosts, gradient current collectors, and composite alloy strategies to guide uniform plating and mitigate volume change; and (2) the cutting-edge application of advanced diagnostics, including multi-scale operando characterization and computational simulations, as essential tools for deciphering the underlying mechanisms of Li deposition and failure. By synthesizing insights across these domains, we further outline persistent challenges, including balancing high areal capacity with long-term cyclability, and present an integrated developmental pathway toward practical high-energy lithium metal batteries. This work underscores that the synergistic integration of structural innovation with multiscale diagnostics is indispensable to unlock the full potential of LMAs.