A calibration calorimetry method to investigate the thermal characteristics of a cylindrical lithium-ion battery

Thermal characteristics of lithium-ion battery cells are crucial in the thermal design of power battery packs for electric vehicles. In this paper, a calibration calorimetry method of considering the heat loss is proposed to investigate the thermal characteristics of a commercial cylindrical 21700 cell. In the meantime, an existing heat-flux meter method is employed to analyze the present method effectiveness. Furthermore, a cell thermal model by considering the physical specifications and thermal parameters is established to predict the cell's temperature rise during its operation. It is shown that the proposed calibration calorimetry method matches well with the existing heat-flux meter method in determining the cell heat generation rate. The cell heat generation rate increases as the decreasing temperature and the increasing discharge rate, and there exists a quadratic-relationship in them between each other. The established thermal model to predict the cell temperature rise is effective with accuracy of within 3.0 °C. This work is fast and cost-effective in characterizing the thermal characteristics of the commercial cylindrical cells, without resorting to the specialized instruments.