Design of a Calorimeter for Measurement of Heat Generation Rate of Lithium Ion Battery Using Thermoelectric Device

Analysis of thermal behavior of Lithium ion battery is one of crucial issues to ensure a safe and durable operation. Temperature is the physical quantity that is widely used for analysis, but limited for accurate investigations of behavior of heat generation of battery because of sensitivities affected by heat transfer in experiments. Calorimeter available commercially is widely used to measure the heat generation of battery, but does not follow required dynamics because of a relatively large thermal time constant given by cavity and a limited heat transfer capability. In this paper, we proposed a highly dynamic calorimeter that was constructed using two thermoelectric devices (TEMs). For the design of the calorimeter and its calibration, a printed circuit board (PCB) with the same size as the battery was used as a dummy load to generate controlled heat. Dynamics were improved using a lead-lag compensator for temperature control and heat generation was estimated using Kalman filter based on a thermal model of the calorimeter. All parameters were optimized using the PCB. Finally, heat generation rate of a large format of pouch type lithium ion battery was measured and compared with theoretical values.