The demand for autonomous devices, including intelligent sensor platforms for IOT applications, is driving a parallel need for efficient energy storage systems that are inexpensive to produce, exhibit high power and energy densities, and occupy a minimum footprint on the device. Necessary enhancement in the performance of batteries and supercapacitors can be realized by fabrication of hierarchical 3D architectures with dimensional control ranging from the nm to the macroscale, however the most promising structures have proven difficult to achieve using approaches suitable for large scale production.

We are fabricating energy storage devices using combinations of nanoimprint lithography, self-assembly, and novel approaches to high-rate materials synthesis including rapid photothermal processing. In one example, 3D lithium-ion microbatteries are prepared via imprint lithography using inks comprised of LiMn2O4 and Li4Ti5O12 nanoparticles and the battery cell is integrated vertically through layer-by-layer (LBL) assembly. The batteries are shown to possess superior capacity retention and high-power density. We also fabricate hierarchical graphene/carbon/FeOx nanoparticle composite anodes for high performance Li ion batteries using a combination of imprint lithography and photothermal processing, wherein multilayer graphene embedded within a porous carbon matrix is generated in situ from a simple precursor film, eliminating the need for externally sourced graphene. The approaches employed are rapid and highly efficient, enabling batch fabrication for 3D microbattery systems as well as the roll-to-roll production of large energy storage batteries.