Carbon Interlayer with Uniformly Anchored ZnO Nanoparticles: Surface-Energy-Driven Coble Creep for Practical...

Anode-free solid-state batteries (AFSSBs) promise high energy density and improved safety, but their material/manufacturing costs and electrochemical performance remain challenging. Here, cost-effective and high-energy-density AFSSBs are demonstrated using a zinc oxide-carbon composite interlayer (ZnO@C) synthesized via an electron-beam (e-beam) irradiation method. Strong chemical anchoring of ZnO nanoparticles (NPs) smaller than 5 nm on the carbon host ensures their homogeneous dispersion across the interlayer. These ZnO NPs lower the energy barrier for reacting with lithium and serve as a buffer layer during lithium deposition. Moreover, the ZnO NPs with high surface energy induce the formation of finer lithium nuclei, which improves the creep behavior. By suppressing nanoparticle agglomeration, the chemical anchoring preserves the nanoscale morphology during cycling. As a result, the ZnO@C layer anodes exhibit high energy density, stable Coulombic efficiency of greater than 99.8%, and cycle retention of 69.6% after 300 cycles.