Abstract: In order to test the bulk force of lithium-ion batteries during the process of charging and discharging, a lithium-ion battery bulk force test bench is proposed to be developed. The test bench is composed of a mechanical structure part and a measurement and control part. The test system composed of upper/lower battery fixing spacer and battery is the core part of the mechanical structure. Firstly, in order to simulate the influence of different structural spacer on the heat dissipation performance of the test system, the heat dissipation simulation model of the test system is established. The lithium-ion battery is a homogenization model based on the vertical and horizontal section of the battery, and the volume power of the heat source is calculated after HPPC pulse charge discharge test; Secondly, the coupled thermal-mechanical finite element model of the whole test bench is established to analyze the influence of different structural spacers on the bulk force transfer efficiency of the battery. In the model, the interaction between lithium-ion battery and the test bench under the process of charging and discharging is simplified as an equivalent coupled thermal- mechanical; Then short pulse tests and bulk force tests are used to verify the effectiveness of the simulation results. Finally, based on the developed test bench, the bulk force-state of charge(SOC) curves under different preloads are obtained, which provide basic data for the development of a battery management system integrating battery bulk force.

Key words: test bench, battery management system, battery bulk force, numerical simulation analysis