A high-fidelity hybrid lithium-ion battery model for state of energy and circuit characteristics prediction

The state of energy (SOE) of Li-ion batteries is a key indicator for the energy optimization and management of energy storage devices (ESDs) in electric vehicles and smart grids. To improve the SOE estimation accuracy, a hybrid Li-ion battery model is presented against the dynamic loads and the rate energy effects of the battery. In order to acquire advantages of both models, an analytical battery model is merged with an electrical model for accurately tracking the battery voltage characteristics and capturing the nonlinear rate energy effects to realize high-fidelity SOE prediction. Commercial Li-ion batteries are tested at the single-cell level at dynamic loads to validate the effectiveness of the proposed model. The simulation results show high accuracy and reliability of the proposed model for predicting of the terminal voltage and the SOE of batteries under dynamic loads.