A lifetime prediction method for Lithium-ion batteries considering storage degradation of spare parts

Standby redundancy is a common fault-tolerant technique to ensure uninterrupted operation and enhance the reliability of Lithium-ion (Li-ion) batteries. In practice, the performance of standby Li-ion batteries has been found deteriorating with their storage, which may decrease the standby system's lifetime (SSL). Unfortunately, SSL prediction has not been investigated thoroughly by existing researches. Therefore, this paper proposes an iterative method for SSL prediction considering the storage degradation of spare parts. The operating and storage degradation processes are respectively described by two nonlinear Wiener-process-based models, based on which an iterative solution of the SSL under the concept of the first passage time (FPT) is provided. Additionally, random effects have been incorporated, and the proposed iterative method for SSL prediction has also been extended to the case with unit-to-unit variability. Both the numerical simulations and Li-ion batteries example are provided for illustration.