A novel double dynamic stress accelerated degradation test to evaluate power fade of batteries for electric vehicles

High-power lithium-ion batteries are being deployed in various transportation carriers such as hybrid, plug-in, or full electric vehicles recently. Power fade of lithium cells regarding temperature and charging and discharging rates are being the significant barrier that mitigates its widespread commercialization in the electric vehicle market. A novel double dynamic stress accelerated degradation test (D²SADT) taking an advantage of closing the real driving conditions is developed to reduce the prediction error. The test contains two dynamic stress factors, temperature and cell charging and discharging currents, by which is implemented simultaneously. The test results show that the D²SADT is capable of accelerating the battery degradation where the power of the test cell decreases near 10% after 18 temperature cycles and 900 dynamic cell charging and discharging cycles. Compared to the traditional constant stress test, D²SADT represents more realistic and efficient to evaluate the power fade of batteries used in the electric vehicles.