Architectural integration of the components necessary for electrical energy storage on the nanoscale and in 3D

Abstract

We describe fabrication of three-dimensional (3D) multifunctional nanoarchitectures in which the three critical components of a battery—cathode, separator/electrolyte, and anode—are internally assembled as tricontinuous nanoscopic phases. The architecture is initiated using sol–gel chemistry and processing to erect a 3D self-wired nanoparticulate scaffold of manganese oxide (>200 m² g⁻¹) with a continuous, open, and mesoporous void volume. The integrated 3D system is generated by exhaustive coverage of the oxide network by an ultrathin, conformal layer of insulating polymer that forms via self-limiting electrodeposition of poly(phenylene oxide). The remaining interconnected void volume is then wired with RuO₂ nanowebs using subambient thermal decomposition of RuO₄. Transmission electron microscopy demonstrates that the three nanoscopic charge-transfer functional components—manganese oxide, polymer separator/cation conductor, and RuO₂—exhibit the stratified, tricontinuous design of the phase-by-phase construction. This architecture contains all three components required for a solid-state energy storage device within a void volume sized at tens of nanometres such that nanometre-thick distances are established between the opposing electrodes. We have now demonstrated the ability to assemble multifunctional energy-storage nanoarchitectures on the nanoscale and in three dimensions.