Reliability Characterization and Modeling of Flexible LCO battery Under Flexing and Calendar Aging for SOH degradation analysis

Flexible batteries have received a lot of attention owing to their thin form-factor and their wide applicability due to its flexibility and portability. Reliability of thin flexible power sources under stresses from human body motions are not well understood. Thin lithium-ion power source reliability may depend on use conditions, operating conditions, and storage prior to deployment. The use conditions are related to flexing stress cycles such as twist, fold, stretch, etc. as well as the charging and discharging cycles. Additionally, aging conditions are regarding to thermal aging and calendar aging. In this paper, the use cases have been replicated using lab setups to study the state-of-health degradation of thin power sources during charge-discharge cycling. The flexing test device has been used to replicate the stresses of daily motions, by administering 60-folding and twisting motions during 150 charge/discharging cycles. In addition, a simulation study by finite element method of multi-physics approach has been done for the better understanding of phenomenon of state of health degradation, electro-chemo-mechanical reactions, and life prediction. For the validation of the model, electro-chemical measurements via cyclic voltammetry method have been done. Consequently, various reliability characteristics, life expectations, electro-chemo-mechanical characteristics have been found.