Design Considerations for Practical Li-S Battery Components for Electric Aviation

The development of high-energy, high-safety, and high-power batteries beyond electric automobile requirements is vital for future electric aviation applications. The transition to non-volatile solid-state electrolytes (SSE) promises many advantages over traditional flammable liquid electrolytes and may also be an enabling technology for next generation chemistries. However, significant manufacturing challenges must be overcome before the adoption of such technology. This study focuses on advancement of previous electrolyte development to produce sulfide-polymer composites with densified thicknesses between 20-30 microns using a tape-casting technique with an elastomer binder [1]. Parameters such as binder type, binder loading, and filler loading are modified to determine their impact on electrochemical performance and mechanical stability. The composites were determined to retain reasonable ionic conductivity with improved flexibility and scalability critical for practical manufacturing of such cells. Films were produced 10-15 times thinner than comparable bulk powder electrolytes and within the range of commercial polyolefin separators (25 micron) used in commercial liquid containing lithium-ion cells. Composite conductivities were maintained above 0.2mS/cm, which holds promise for future electric aviation applications. Processing techniques are investigated to further improve electrochemical performance. [1] Donald A. Dornbusch, Rocco P. Viggiano, John W. Connell, Yi Lin, Vadim F. Lvovich. Practical considerations in designing solid state Li-S cells for electric aviation, Electrochimica Acta, 2021, 139406, ISSN 0013-4686, https://doi.org/10.1016/j.electacta.2021.139406.