Modelling and simulation of high- and low-speed impact damage of lithium batteries for light and small UAVs

In this study, the high- and low-speed impact damage of lithium batteries for light and small UAVs was investigated through the combination of experimental and simulation methods. A high-precision finite element model of the lithium battery was built, impact compression tests were performed for battery cells and battery modules to investigate the mechanical behavior of the lithium battery under the low-speed impact. In addition, the failure parameters of the lithium battery model were modified through battery cells and battery modules impact compression tests. In this paper, we designed and implemented a battery modules air cannon impact test on aluminum plates. The results achieved using the target impact simulation model of lithium batteries were compared with the results of the lithium battery target impact test. The peak strain error was obtained as 5.1%, the error of the back abrupt deformation of the aluminum plate after the target impact test was found as 5.67%, and the error of the approximate circle diameter of the aluminum plate crater reached 2.23%. The numerical simulation results of the lithium battery target impact were well consistent with the results of the target impact test, thus verifying the accuracy of the lithium battery finite element model built in this study under the high-speed impact. As revealed by the results, when the fall impact speed was higher than the normal flight speed of the UAV, the protective effect of the external battery box on the internal battery cell was found to decrease rapidly; the higher the impact speed, the more serious the damage of the internal single lithium battery would be, thus suggesting that the lithium battery under the high-speed impact would have a high risk of explosion and fire.