Light-weight High-power Lithium-ion Battery Technologies for Small SAR Satellite

Until now, the highest rate of lithium-ion battery for SAR satellite is 5 C. With the increasing requirements of light weight, related indicators can be achieved through improving rate performance and maintaining high specific energy. To meet this demand, light-weight high-power lithium-ion battery technologies for small SAR satellite have been systematically developed, including electrode active materials research, separators improvement, and electrolytes formula design. Using LiNi0.8Co0.15Al0.05O2 (NCA) materials possessing both energy and power performances as cathode materials, the design capacity of battery has been increased by 15.6% and 29%, respectively, compared with that of power lithium batteries using Li1+zNixMn1-x-yCoyO2 (NMC) and LiCoO2 (LCO) materials as cathodes. Through comparing the power performances of different types of graphite anode materials, it is found that the discharge voltage plateau under 10 C rate can be increased by 0.2 V by improving the specific capacity based on particle-size control. Besides, the effect of types of ceramic separator coating layer and separator substrates on the power performance of lithium battery has been studied. It is found that the discharge voltage plateau under 10C rate can be increased by 0.4 V and the power platform kept stable during the discharge process when dry-process polyolefin film as the substrate and Al2O3 as the ceramic coating were employed. Furthermore, for the bottleneck of poor high-temperature and cycling stability of NCA materials, the effects of several types of electrolytes on batteries’ high-rate discharge and rate cycling were compared and studied. In this study, high-power lithium-ion battery applied for small SAR satellite has been successfully prepared, exhibiting a specific capacity of 180 Wh/kg with continuous discharge capability of 10 C.