Abstract:

Energy storage is an important part of the new power system and plays an important role in achieving carbon peak and carbon neutrality. Lithium-ion may cause the power station to burn or explode when they encounter extreme abuse under the influence of internal and external triggers such as electricity, heat, and mechanics. For a long time, research on safety early warning technology for lithium-ion battery energy storage based on battery temperature, gas, internal resistance, and voltage characteristics has been widely concerned. This paper constructs a multiparameter test platform for overcharge thermal runaway of batteries and studies the voltage, temperature, and deformation change characteristics of prismatic lithium iron phosphate battery cells during the process ofcharge thermal runaway. The results show that the large surface of the prismatic lithium iron phosphate battery cell detects deformation earlier than the side surface because of the use of fixtures in experiment, and the final deformation amount of the large surface is less than that of the side surface. The upper surface sensor of the prismatic lithium iron phosphate battery cell can change. The deformation monitoring of the prismatic lithium iron phosphate battery cell is 100 seconds ahead of the temperature monitoring, which plays a certain role in preventing the occurrence of and the expansion of fault scale in energy storage power stations, and also reserves more time for the fault handling of energy storage batteries. This method provides a new direction for the safety early of lithium-ion batteries for energy storage and further technical support for the later application of energy storage projects.

Key words: energy storage, lithium-ion battery, safety warning, surface deformation