Electrochemical modeling and parameter sensitivity of lithium-ion battery at low temperature

The highly temperature-dependent performance of lithium-ion batteries (LIBs) limits their applications at low temperatures (<-30 °C). Using a pseudo-two-dimensional model (P2D) in this study, the behavior of fives LIBs with good low-temperature performance was modeled and validated using experimental results. The effects of eight different parameters including the active material volume fraction, particle radius and initial lithium-ion concentration in positive and negative electrodes, initial liquid lithium-ion concentration, and separator porosity on the low-temperature performance of these five LIBs were investigated. In order to evaluate the sensitivity of each parameter, the slope of discharge capacity change with respect to the change of each parameter was used. According to the results, the change in the structural parameters of the negative electrode had a more significant impact on the low-temperature performance of LIBs than the structural parameters of the positive electrode. The results showed that the sensitivity of particle radius, active material volume fraction and initial lithium-ion concentration in the negative electrode is approximately 49, 32 and 11 times higher than the positive electrode, respectively. Also in the negative electrode, the sensitivity of the particle radius is approximately 1.4 and 2 times higher than the sensitivity of the active material volume fraction and initial lithium-ion concentration, respectively.