Regulating electrodeposition morphology in high-capacity aluminium and zinc battery anodes using interfacial metal-substrate bonding

Although Li-based batteries have established a dominant role in the current energy-storage landscape, post-Li chemistries (for example, Al or Zn) are emerging as promising candidates for next-generation rechargeable batteries. Electrochemical cells using Al or Zn metal as the negative electrode are of interest for their potential low cost, intrinsic safety and sustainability. Presently, such cells are considered impractical because the reversibility of the metal anode is poor and the amount of charge stored is miniscule. Here we report that electrodes designed to promote strong oxygen-mediated chemical bonding between Al deposits and the substrate enable a fine control of deposition morphology and provide exceptional reversibility (99.6-99.8%). The reversibility is sustained over unusually long cycling times (>3,600 hours) and at areal capacities up to two orders of magnitude higher than previously reported values. We show that these traits result from the elimination of fragile electron transport pathways, and the non-planar deposition of Al via specific metal-substrate chemical bonding. Using metal anodes could in principle boost the energy density of batteries but their electrodeposition often negatively impacts battery performance. Here the authors propose an oxygen-mediated metal-substrate bonding strategy to regulate metal deposition and demonstrate highly reversible Al and Zn anodes.