DEVELOPMENT AND VALIDATION OF A LITHIUM-ION POLYMER BATTERY CELL MODEL FOR 12V SLI BATTERY APPLICATIONS

摘要

An intuitive and comprehensive lithium-ion polymer battery cell model is developed in the Simulink environment. The developed model has capability of transient function in the Thevenin-based model, AC-equivalent function in the impedance-based model, and runtime prediction in the runtime-based model. Several model parameters are determined through five experimental discharging currents (6.67A, 10A, 20A, 30A, and 40A). The model is correlated and validated with other three continuous discharging currents (4A, 15A, and 50A) and two pulse discharges (20A and 30A). The validation indicates a less than 7% discrepancy between model simulation and experiment. The model is currently effective for lithium-metal-oxides polymer battery cell with capacity between 18Ah and 22Ah (20Ah +/- 10%). For other capacity battery cell, the parameters of series resistors need to be adjusted in the model. These parameters can be determined using three to five continuous constant current discharging tests. It is intended to make the developed cell model scalable and accurate in a wider ranges of battery specifications. Expending the developed cell model to a 12 voltage Starting-Lighting-Ignition (SLI) battery used in the start-stop or 48 voltage battery pack for mild hybrid electric vehicle is an example.