The Effect of Electrode Thickness on the High-Current Discharge and Long-Term Cycle Performance of a Lithium-Ion Battery

Abstract

Six groups of electrodes with different thickness are prepared in the current study by using Li[Ni1/3Co1/3MN1/3]O2 as the active substance; the electrode thicknesses are 71.8, 65.4, 52.6, 39.3, 32.9, and 26.2 μm, respectively, with similar internal microstructures. The effect of electrode thickness on the discharge rate, pulse discharge, internal resistance, and long-term cycle life of a pouch cell are investigated. The results show that, with the decrease in the electrode thickness from 71.8 μm to 26.2 μm, the high-current-discharge performance of the cell gradually improves, the pulse-discharge power density under 50% SOC increases from 1561 W/Kg to 2691 W/Kg, the Rdis decreases from 8.70 mΩ to 3.34 mΩ, and the internal resistance decreases from 3.36 mΩ to 1.21 mΩ. In the long-term cycle-life test, the thinner the electrode thickness, the less the capacity fading of the cell; the internal resistance of the cell is observed with the increase in the cycle index.