Abstract:Anode-free alkali metal batteries (AFAMBs) are regarded as a promising next-generation energy storage technology, featuring high energy density, low manufacturing cost and simple structure. However, the anode side is confronted with challenges such as unstable solid electrolyte interface (SEI), dendrite growth, irreversible deposition and severe volume changes, caused by the high reactivity of alkali metals. These issues severely limit the cycle life and commercialization of AFAMBs. In response to these issues, non-ferrous metals play key roles in the construction of the functionalized interfaces on the anode side of AFAMBs due to their excellent electrical conductivity, favorable mechanical properties and the ability to induce alkali metals. This article focuses on various strategies and mechanisms: (i) constructing alkaliphlic interface layers (e. g. , Au, In) to reduce the nucleation barrier and guide uniform deposition; (ii) building in-situ/artificial SEI with Ru, Zn, etc. , to enhance interface stability and suppress side reactions and dendrite growth; (iii) implementing three-dimensional porous scaffolds to alleviate volume strain and optimize ion/electron transport; (iv) developing advanced alloys and composite current collectors to regulate interface deposition behavior and improve cycle reversibility. This article further analyzes the research progress in the mechanism of non-ferrous metals in aspects such as lattice matching and electronic structure modulation. By introducing high affinity non-ferrous species or reconfiguring crystal planes, the energy barrier can be reduced and homogeneous nucleation can be guided. Certain non-ferrous metals with specific atomic radii facilitate in-situ alloying during deposition, forming stable alloy phases, ensuring reversible deposition. Moreover, by integrating non-ferrous nanoclusters, single-atom coordination bonds, or heterostructures with specific active sites, the local current density can be regulated, thereby accelerating ion transport kinetics, homogenizing the electric field and inhibiting dendrite growth. Future research should prioritize the development of cost-efficient modification materials; develop green, simple, and compatible functionalization techniques with existing production lines; and design advanced computational models to predict interface evolution, ultimately providing support for high-performance AFAMBs.
