Fiber-based anode for lithium metal battery: Ion deposition behavior, interface stabilization mechanisms, and advanced characterization

With the urgent demand for efficient energy storage systems, Lithium-ion batteries struggle to meet the growing need for high energy density. Therefore, there is an urgent need to develop new lithium battery systems with high energy density and long cycle life, as electrode material development is crucial for enhancing energy density. Lithium metal, with its low redox potential and high theoretical specific capacity, is a highly promising anode material for achieving high energy density in next-generation battery systems. However, the practical application of lithium metal anodes still faces severe challenges, such as uncontrollable dendrite growth and significant volume expansion. The development of functional nanomaterials has brought opportunities for the revival of lithium metal anodes. Among them, nanofiber materials exhibit great potential in lithium metal anodes due to their unique functional and structural characteristics. This paper systematically reviews the recent research progress of nanofiber materials in lithium metal batteries and the advanced characterization techniques. Firstly, the preparation of fiber-based lithium metal anodes is reviewed, with a detailed introduction to the principles and characteristics of various nanofiber forms compounded with lithium metal. Secondly, the deposition mechanism of the lithium metal interface is discussed in depth from multiple perspectives, including current distribution, reduction of nucleation barriers, and gradient design. Finally, using advanced characterization techniques, the structural characteristics and performance improvements of fiber-based lithium metal anodes are summarized from the nanoscale, mesoscale, to the microscale. These studies provide an important theoretical foundation and practical guidance for the development of high-performance lithium metal batteries.