Study on the High Voltage and High Power Lithium ion Battery

Abstract

Li-ion battery has become the most widely used battery with the advantages of high energy density, good cycling performance and no memory effect. With the development of various equipment in the aspect of aerospace, high-voltage, high energy and power density lithium-ion battery has been studied at home and abroad, which was mainly used in unmanned aerial vehicles.In this paper, a battery system was assembled by 11 modules connected in series, and a module was combined in 2 parallels and 11 series by 22 cells, that was, the battery system was combined of 242 cells in 121 series and 2 parallels. In order to achieve isolated installation and series-parallel connection, a frame structure was used to encapsulate the cells in the modules. Finally, a battery system with a nominal voltage of 440V, an energy greater than 4kWh and a power greater than 90kW was completed, of which the specific energy reached to 140Wh/kg. And it can be discharged continuously at 20-25C. The working temperature range was -2 °C-55 °C. And the battery system showed good power performance and low-temperature performance. The related technology can be widely used in high-voltage and high-power energy storage devices, such as SAR energy supply.