Abstract: Domestic power stations of LiFePO₄ battery energy storage have been built and put into operation on a large scale, however, the thermal runaway risk of lithium iron phosphate batteries is relatively prominent, and the fire hazard of energy storage power stations always exists. Aiming at the LiFePO₄ battery, we designed the adiabatic thermal runaway fixed-point cooling experiments. The electrical and material characteristics of LiFePO₄ batteries in different stages of thermal runaway were studied. Then, the starting temperature point of self heating, the starting temperature point of self production heat, the opening temperature point of pressure relief valve and the highest temperature point of thermal runaway were gained. Finally, change rules of composition and structure changes of solid components such as positive pole, negative pole and diaphragm were analyzed. The results show that the initial reaction of thermal runaway of LiFePO₄ battery is mainly concentrated in the negative pole and electrolyte, and the safe treatment temperature range is 60~100 ℃ under the risk of thermal runaway. The study can provide important data support for the safety protection and thermal runaway warning of LiFePO₄ battery energy storage power stations.