Synergistic effect of mixed cathode materials on lithium-ion batteries

Abstract

During the charging and discharging of lithium-ion batteries, the internal reaction of the battery changes in temperature, because the thermal stability of the ternary cathode material is not stable, it affects the normal operation of the battery and also affects the available capacity of the battery. Many researchers have mixed two positive electrode materials to prepare electrodes and then improved the rate performance and polarization of the electrodes. The active material of the mixed electrode is mainly made by physical mixing of two or more lithium intercalation compounds. Compared with a single active material, the purpose of a mixed electrode is to balance the performance of two or more active materials. Taking the ternary material as the research object, the modification method is to use the grinding method to mix and stir the lithium iron phosphate (LiFePO4) and the ternary cathode material LiNi1/3co1/3Mn1/3 (NCM) with an appropriate mass ratio to the electrode plates to assemble a lithium ion battery and then explore their various characteristics. The mixed material electrodes uses field emission scanning electron microscopy, infrared spectroscopy and X-ray diffraction to characterize the surface structure, chemical composition, then uses blue electricity test equipment to measure the electrochemical performance of the mixed cathode material, test cycle performance and rate, and use electrochemical workstation to test the volt-ampere curve and electrochemical impedance test of the lithium-ion battery to study the capacity reversibility and electrochemical polarization degree of the mixed cathode material.