Direct Imprinting of Scalable, High-Performance Woodpile Electrodes for Three-Dimensional Lithium-Ion Nanobatteries

The trend of device downscaling drives a corresponding need for power source-miniaturization. Though numerous microfabrication methods lead to successful creation-of shbmillimeter-scale electrodes, scalable approaches that provide cost-effective narioscale resolution for energy storage devices. such as on-chip batteries remain elusive. Here, we report nanoimprint lithography (NIL) as a direct patterning technique to fabricate high-performance TiO2 nanoelectrode arrays for lithium-ion batteries (LIES) over relatively large areas. The critical electrode dimension is below200 nm, which enables the structure to possess favorable rate capability even under dischating current densities as high as 5000 mA =g(-1). In addition, by sequential imprinting, electrodes with three-diinensional (3D) woodpile architecture were readily made iri a "stack-up" Manner. The height of architecture can be easily controlled by the number of stacked layers, while maintaining nearly, constant surface-to-volume ratios. The result is a proportional increase of areal capacity with the number cif layers. The structure-processing combination leads to efficient use of the material, and the resultant specific capacity (250:9 mAh g(-1)) is among the highest reported. This work provides a simple yet effective strategy to fabricate nanobatteries and can' e potentially extended to other electroUctive materials.