NSF/EPSCoR: High Resolution In Situ Imaging of Solid State Li-ion Nanobatteries

Battery technology is of crucial importance to space operations, since equipment designed to operate in space must be able to collect solar energy during periods of sunlight, and store it for use during darkness. Li-ion batteries are of particular interest due to their superior energy density, non-toxic and lightweight components, and longevity. Recent breakthroughs in Li-ion battery technology include the use of nanostructured components to increase the active area and reduce the volume effect of fracture, and, fully solid-state battery cells to increase the safety of operation - of particular importance at high temperature. We propose to develop a technique to observe the effect of the charge/discharge process in a nano-scale Li-ion battery, to observe and correlate microstructural changes in the anodic and cathodic regions for the first time simultaneously. Nanowires of prototypical electrode materials will be observed in situ, and the size dependence of fracture discerned using a variety of nanowire diameters. Further, our technique should be widely applicable to any new electrode material currently under development and is therefore of great future interest. Finally, the effect of cycling the nanobattery at elevated temperatures will be investigated by repeating in situ device tests at the increased temperatures potentially experienced by power sources traveling to, and operating outside of the Earth's atmosphere.