Development of Lithium-ion Battery Test Bench

A test bench is proposed to be developed to measure relevant mechanics responses of lithium-ion batteries during different charge and discharge processes. It primarily consists of two parts: a mechanical structure part and a measurement and control part. The test system composed of an upper/lower battery fixing spacer and a battery is the core part of the mechanical structure part. This measurement and control part mostly contains an environmental control, an acquisition as well as a charge discharge system. For this mechanical structure part, firstly heat dissipation simulations of test systems with different structural spacers are performed to preliminarily select a structural test system with better heat dissipation performance to guarantee its local heat dissipation performance; Secondly, the coupled thermal-mechanical finite element model of this whole test bench is modeled to analyze the influence of different structural spacers on the bulk force transfer efficiency of the battery and to ensure the safety of lithium-ion batteries in the test bench during charge and discharge tests. In the model, the interaction between a lithium-ion battery and this test bench in the charge and discharge processes 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, which provide references for the development of the same type of lithium-ion battery test benches. Based on the developed test bench, bulk force-SOC curves under different preloads and swelling -SOC curves at a variety of discharge rates are obtained, which provide base data for the research of battery management systems integrating swelling-bulk force.