Currently, there is a growing need to improve the power performance of batteries, which would enable faster charging and improved performance of electronic devices. However, the internal kinetics of most batteries prevent the rapid transport of electrons and ions, which limits power density. We have developed hierarchical battery architectures and advanced manufacturing technologies to dramatically increase the power density of primary and secondary microbatteries by controlling ion and electron transport across nm – mm scales. We seek to further understand the limits of electron and ion transport, reduce heat generation and improve thermal transport in high power batteries, and develop high power architectures for conventionally sized batteries.
High power microbatteries:
In this project we designed and fabricated hierarchical microbatteries with unprecedented power density. The three-dimensional bicontinuous interdigitated microbattery architecture improved power performance by simultaneously reducing ion and electron transport distances through the anode, cathode, and electrolyte. The microbattery power densities were up to 7.4 mW cm-2 mm-1, which equals or exceeds that of the best supercapacitors, is 100X greater than conventional batteries, and is 2000 times higher than that of other microbatteries. Electrochemical deposition techniques improved the microbattery energy density while maintaining high power density by allowing high volume fractions of electrochemically active material to be integrated into the high power architectures.
High power primary microbatteries:
In this project we developed technologies for integrating high volume fractions of high capacity materials into a primary microbattery. The primary microbatteries had similar energy densities to commercially available lithium/manganese oxide based primary batteries with a ~50 X higher peak power density.
Holographic lithography for on-chip microbattery integration:
In this project we demonstrated a high-performance microbattery suitable for large-scale on-chip integration with both microelectromechanical and complementary metal-oxide–semiconductor (CMOS) devices. Enabled by a 3D holographic patterning technique, the battery possessed well-defined, periodically mesostructured porous electrodes. Such battery architectures offer both high energy and high power, and the 3D holographic patterning technique offers exceptional control of the electrode’s structural parameters, enabling customized energy and power for specific applications.
 James H. Pikul, Jinyun Liu, Paul V. Braun, William P. King, “Integration of high capacity materials into interdigitated mesostructured electrodes for high energy and high power density primary microbatteries.” Journal of Power Sources, vol. 315, pp. 308-315, 2016.
 Hailong Ning, James H. Pikul, Runyu Zhang, Xuejiao Li, Sheng Xu, Junjie Wang, John A. Rogers, William Paul King, and Paul V. Braun, ” Holographic Patterning of High Performance on-chip 3D Lithium-ion Microbatteries”, Proceeding of the National Academy of Sciences, vol. 112, no. 21, pp. 6573-6578, 2015.
 Jinyun Liu, Huigang Zhang, Junjie Wang, Jiung Cho, James Pikul, Eric Scott Epstein, Xingjiu Huang, Jinhuai Liu, Paul V. Braun, “Hydrothermal Fabrication of Three-Dimensional Secondary Battery Anodes”, Advanced Materials, vol. 26, no. 41, pp. 7096-7101, 2014.
 James H. Pikul, Huigang Zhang, Jiung Cho, Paul V. Braun, and William P. King, “High power lithium ion micro batteries from interdigitated three-dimensional bicontinuous nanoporous electrodes”, Nature Communications, vol. 4, pp. 1732, 2013
 Paul V. Braun, Jiung Cho, James H. Pikul, William P. King, and Huigang Zhang, “High power rechargeable batteries”, Current Opinion in Solid State & Materials Science, vol. 16, pp. 186 – 198, 2012.