Life prediction model and performance degradation of lithium-ion battery under different cut-off voltages

Battery lifetime prediction is critical to successfully introducing new products to the market, and a long testing time will affect the promotion of the product. In this paper, The prediction model of battery cycle life composed of cut-off voltages and state of health (SOH) is established based on an inverse power law equation to evaluate the NCM(811)battery. It is found that the capacity is more sensitive to the charge cut-off voltages (CCOV) than to the discharge cut-off voltages (DCOV). The capacity degrades to 67.3 % at 180th cycle in the range of 3–4.4 V, while it is 65.8 % at 380th cycle in the range of 2.5–4.2 V (the normal work voltage of battery is 3–4.2 V). The internal resistance and capacity degradation of the battery is analyzed by the incremental capacity curve and the hybrid pulse power characterization (HPPC) test. The error between prediction and measurement is less than 3 % within 400 cycles, and the model can predict the battery lifetime under different conditions (SOH, voltage). It helps to shorten the test time of new products and optimize the operating conditions of battery.