Innovating lithium metal batteries through anode-free design in solid-state systems: Materials challenges and perspectives

ABSTRACT Anode-free solid-state lithium batteries (AFSSLBs) are promising candidates for advanced energy storage, offering theoretical gravimetric energy density up to 400 Wh·kg -1 and volumetric energy density exceeding 1500 Wh·L -1 , while maintaining the safety benefits of solid-state electrolytes (SSEs). However, their practical adoption faces technical challenges such as interfacial instability, dynamic volume changes, and uneven lithium plating behavior. Consequently, current collector engineering has become a critical focus of battery research, as it directly influences lithium deposition uniformity and electron transport efficiency. This review examines three current collector architectures for AFSSLBs based on copper, steel, and carbon. Emerging strategies such as three-dimensional (3D) topology design, bi-continuous electron/ion transport pathways, gradient lithiophilic interfaces, and interfacial engineering through coatings showing promise in controlling Li deposition and suppressing dendrites. Optimizing charge collector architectures and interfaces could enable high-density, high-safety energy storage systems with mitigated thermal runaway risks under extreme conditions. Future progress in AFSSLBs hinges on integrating material innovation, interface engineering, advanced manufacturing, and system design to transcend existing battery limitations.