Online State-of-Health Estimation for Fast-Charging Lithium-Ion Batteries Based on a Transformer–Long Short-Term Memory Neural Network

With the rapid development of machine learning and cloud computing, deep learning methods based on big data have been widely applied in the assessment of lithium-ion battery health status. However, enhancing the accuracy and robustness of assessment models remains a challenge. This study introduces an innovative T-LSTM prediction network. Initially, a one-dimensional convolutional neural network (1DCNN) is employed to effectively extract local and global features from raw battery data, providing enriched inputs for subsequent networks. Subsequently, LSTM and transformer models are ingeniously combined to fully utilize their unique advantages in sequence modeling, further enhancing the accurate prediction of battery health status. Experiments were conducted using both proprietary and open-source datasets, and the results validated the accuracy and robustness of the proposed method. The experimental results on the proprietary dataset show that the T-LSTM-based estimation method exhibits excellent performance in various evaluation metrics, with MSE, RMSE, MAE, MAPE, and MAXE values of 0.43, 0.66, 0.53, 0.58, and 1.65, respectively. The performance improved by 30–50% compared to that of the other models. The method demonstrated superior performance in comparative experiments, offering novel insights for optimizing intelligent battery management and maintenance strategies.