Manufacturability of composite laminates with integrated thin film Li-ion batteries

The limits of processability of solid-state thin film lithium-ion batteries embedded into composite laminates are identified through testing under pressure, temperature and a liquid resin environment representative of composite processing cycles. Battery failures are characterized based on optical microscopy and capacity retention, and three distinct types of failures are recognized and analyzed. Failures are associated either with the battery polymeric sealant failure or with the physiochemical degradation of the electrolyte or the anode. Results give evidence that the cure temperature is the most influential parameter for battery survivability. Based on these experimental results, the optimum curing cycle is identified and embedding tests that retain full battery capacity are successfully performed. The minimal three-layer battery packaging proves to be an efficient air and moisture barrier within the above conditions.