Multifunctional Applications of Thin Film Li Polymer Battery Cells

Commercial off-the-shelf (COTS) thin-film solid-polymer Li-ion battery cells appear to posses the requisite physical characteristics for dual use as both electrical energy-storage devices and structural members under a finite load. One realistic application could be small electric unmanned vehicles where the power requirements are in the range of 10 to 100 watts and the mechanical loads are relatively small. We tested the multifunctional feasibility of COTS battery cells by designing a specific mechanical testing protocol based on realistic use in unmanned vehicles. Our characterization protocol included randomized bending and shear testing and generation of energy-power relation (Ragone) plots of the COTS cells. The results indicate that multifunction applications of COTS Li polymer battery cells are feasible; however, battery packaging geometry and bonding are critical design issues.