Physics-informed mixture of experts network for interpretable battery degradation trajectory computation amid second-life complexities

Retired electric vehicle batteries offer immense potential to support low-carbon energy systems, but uncertainties in their degradation behavior and data inaccessibilities under second-life use pose major barriers to safe and scalable deployment. This work proposes a Physics-Informed Mixt ure of Experts (PIMOE) network that computes battery degradation trajectories using partial, field-accessible signals in a single cycle. PIMOE leverages an adaptive multi-degradation prediction module to classify degradation mode s using expert weight synthe sis underpinned by capacity-voltage and relaxation data, producing latent degradation trend embeddings. These are input to a use-dependent recurrent network for long-term trajectory prediction. V a lidated on 207 batteries across 77 use conditions and 67,902 cycles, PIMOE achieves an average mean absolute percentage (MAPE) errors of 0.88% with a 0.43 ms inference time. Compared to the state-of-the-art Informer and PatchTST, it reduces computational time and MAPE by 50%, respectively. Compatible with random state of charge region sampling, PIMOE suppor ts 150-cycle forecasts with 1.50% average and 6.26% maximum MAPE, and operates effe ctively even with pruned 5M B training data. Broadly, PIMOE framework offers a deployable, history-free solu tion for battery degradation trajectory computation, redefining how second-life energy storage systems are asse ssed, optimized, and integrated into the sustainable energy landscape.