Study On The Characteristics Of 18650 Lithium-ion Battery Array Under Low Temperature And Large Current Condition

In civil aviation,Lead-acid and nickel cadmium batteries have increased their work burden because of their large volume and high weight.Lithium-ion batteries have been widely used because of their advantages of high energy density,low self-discharge rate and no memory effect.At present,scholars at home and abroad have studied the performance of lithium-ion battery monomers at low temperature,and the research on the operating characteristics of the lithium-ion battery array under low temperature and high current conditions is less.Therefore,the research on the performance of 18650 lithium-ion battery array under low temperature and large current conditions has certain theoretical guidance and reference value for the use and maintenance of lithium-ion power supply in civil aviation fieldThis paper designs a hardware circuit test system based on STM32 main control circuit and LTC6803 equalization circuit,and builds a low temperature experimental environment.The 18650 lithium-ion battery array was tested under different temperature and working current.The data of discharge current,discharge voltage,internal resistance of cell monomer and the temperature of the outer surface of the battery were collected.The effect of low temperature on charge and discharge characteristics of 18650 lithium-ion battery array is studied.The difference in the balance efficiency of the hardware circuit test system at normal temperature and low temperature is compared and analyzed.Through the analysis of the experimental data,the conclusion is drawn:It is obtained that the discharge capacity of the 18650 lithium-ion battery array will be obviously attenuated with the decrease of temperature below 0°C.The resistance and dispersion of the single cell will become larger,which increases the balance difficulty of 18650 lithium-ion battery array.At the same time,the lower the temperature,the greater the current of the system,the problem of temperature rise of the 18650 lithium-ion battery array is also more prominent.In addition,in the charging process,the low temperature environment makes the charge capacity of the18650 lithium-ion battery array reduced,the dispersion of the battery voltage increases obviously,and the equilibrium strategy with the battery voltage as the equilibrium parameter is limited.