Battery is widely suggested as a reservoir to fasten the power balance between supply and demand. Amongst a variety of batteries, lithium-ion battery technology is the most promoted. However, most of the battery models in the power system simulation are assumed that the battery has a fixed electrical performance, while in reality, this is related to various factors, such as temperature and aging. In order to precisely model the battery, this paper proposes an easy-to-use lithium battery model considering multiphysics, including electrodynamic field, thermodynamic field, and lifetime field. The parameter identification of the proposed model has also been provided. Real battery experimental data serves to verify the accuracy of the proposed model. The simulation results prove that the temperature and aging can significantly degrade battery performance, the process of which can be well captured by the proposed model.