Abstract: Energy storage power stations are critical equipment for mitigating the fluctuations of renewable energy and ensuring the safe and stable operation of power grids. Conducting research on battery aging modeling and health state analysis is essential for extending the service life of power stations and formulating scientific operation strategies. To this end, this paper first establishes a linear battery aging model by incorporating key factors such as operation time, temperature, state of charge, and depth of discharge, and proposes an aging factor model suitable for engineering application scenarios to quantify the influence laws of various factors on the health state of energy storage power stations. Furthermore, combined with the formation and evolution mechanism of the solid electrolyte interphase film of lithium batteries, a nonlinear battery aging model is proposed, which can accurately characterize the aging characteristics of batteries in different life stages of energy storage power stations. Finally, the proposed nonlinear model is verified based on experimental data, and the results confirm the effectiveness of the proposed model.