Life prediction model for lithium-ion battery considering fast-charging protocol

Abstract

With the development of fast-charging technology, fast-charging protocols have been widely used in electric vehicles. However, charging the same type of lithium-ion batteries with different fast-charging protocols has an impact on the cycle life of the battery. Considering the impact of fast-charging protocols on battery life, this paper proposes a life prediction model for lithium-ion batteries that charge with fast-charging protocols. First, the charging-based features are extracted from charge data using dilated convolutional network. Second, the discharging-based features extracted from the discharge curve are enhanced using deep neural network. Finally, the charging-based features and the discharging-based features are merged and fed into random forest regression to predict the cycle life of lithium-ion batteries. Considering that hyperparameters of the model have great influence on the prediction performance, the Bayesian optimization algorithm is used to optimize the hyperparameters of random forest regression. Two public datasets are used for validation. The experimental results show that the proposed method is significantly superior to other existing algorithms for battery cycle life prediction. The relative importance of the charging-based features and the discharging-based features for predicting battery life is also explored.