Study On The Design And Performance Of Lithium Ion Battery For Micro Satellite

Lithium ion battery has its outstanding characteristics such as high voltage, long life, high specific energy, wide range of using temperature, small volume, light quality, charging fast, no memory effect and so on, which satisfy satellite's higher demand for power supply system, at the same time, increase efficiency load and decrease the quality of satellite. Lithium ion battery as ideal energy source can produce much more economic benefit in 21 century.The design and performance of lithium ion battery were studied. The battery structure and the performance of charge and discharge, safety, consistent and cycle were mainly studied. The experiments of cycle and environment simulation simulating Low Earth Orbit Satellite were also carried.The positive material of A company was choose after its charge and discharge and rate performance were evaluated. The battery structure, shell and hermetic parts were designed according to material characteristic and battery parameters, and the battery was prepared at last.The capacity retention was 98% at 2C.When discharging at -10℃, -20℃, and 30℃, the capacity retention was 97.1%, 91.7% and 83.3% respectively. When discharging with 100% depth of discharge (DOD) at 0.5C, the power density was over 150Wh/kg, and the capacity retention was 86.6% after 940 cycles. The battery exhibited good charge and discharge performance.The over charging voltage of 10Ah battery only reached 5.6V, thus its performance needs to be further improved. The battery passed a number of safety tests such as heating in oven, crushing, over-discharging. From the consistent experiment it was shown that the battery exhibited good performance, and the voltage difference ranged between -0.018V and 0.018V in the whole process. The battery resistance was low, but its consistency needed to be improved.The experiment simulating Low Earth Orbit Satellite on earth was done. It was shown that cycle number was over 22080, 19480 and 11950 respectively at 25%DOD, 30%DOD and 40%DOD, and the battery voltage was no less than 3.6V. There was no gas produced and no liquid leaked in the whole experiment. The pile voltage was about 25.5V after 120 cycles and became steady gradually. The battery exhibited good charge and discharge and cycle performance.