Investigation of the Effect of State-of-Charge and C-rates on the Heat Loss and Efficiency of a Lithium-ion Battery

To comprehend the thermal behaviour, performance and the dependency of the affecting parameters such as state-of-charge and C-rates on the heat loss, efficiency, heat flux and maximum temperature of a commercial pouch type lithium-ion battery under various working conditions, different loading were applied to the battery. The capacity of the battery is 13Ah, which has a lithium titanate oxide based anode from Altairnano. Surface temperatures and heat flux of the Lithium-ion battery cell were measured by means of isothermal battery calorimeter. Different charge and discharge current pulses with different C-rates at ten state of charge (SOC) levels from 10% to 90% SOC were applied to the battery by using Maccor automated test system. It was concluded that heat losses demonstrated approximately decreasing pattern from 10 % SOC to 90% SOC.