Preparation and morphology of three-dimensional structured LiMn2O4 films

LiMn2O4 films with vertically aligned holes were formed by electrostatic spray deposition (ESD) and subsequent annealing. Different surface morphologies, such as dense grains, 1 μm-diameter pores with 1 μm-thick walls, and 5 μm pores with 3 μm walls, were formed by varying the lithium sources in the precursor solution. The randomly oriented pores in the films prepared using ESD were rearranged in vertical stacks after annealing to produce crystalline LiMn2O4. This process would be suitable for constructing three-dimensional interfaces between active materials and solid-state electrolytes.