Nonparametric Estimation of Surface Temperature of Li-Ion Cells Using Thermal Impulse Response

Abstract

This paper focuses on the prediction of temperature profiles on the surface of lithium-ion cells using a nonparametric method. In particular, this paper proposes the adoption of the impulse response technique to compute and interpret cell surface temperatures through generic discharge conditions. The method requires data obtained from dedicated experiments performed on the targeted cell. In order to develop the proposed method, these experiments aim at obtaining cell surface overshoot in temperature profiles consequent upon current discharge impulses that are used as reference inputs. A set of dedicated experimental validations is included in this paper to verify the accuracy of the proposed method for different states of health of the cell and environmental conditions. The results show an error in the temperature prediction of <1.8% in the entire predicted temperature subject to generic current discharge profiles as well as a negligible error on the predicted peak temperature. It is important to underline that the proposed technique does not require any knowledge of the internal structure of the targeted cell or any properties of material.