Graphite modified LiNi1/3Co1/3Mn1/3O2 cathodes with improved performance for lithium-ion battery

To reduce the contact between the cathodes and electrolyte, the surface of the LiNi_1/3Co_1/3Mn_1/3O₂ (NCM) cathode was modified with graphite by screen printing. The X-ray diffraction (XRD) test results show that the crystalline structure of the modified NCM cathodes did not change obviously. The morphology of the pristine and modified NCM cathodes were characterized by scanning electron microscopy (SEM), and the results revealed that flake graphite were detected on the surface of the modified NCM cathodes. The performance of both cathodes were evaluated by galvanostatic charge and discharge tests, and it could be concluded that the modified NCM cathodes have better cycling performance and high rate capability than the pristine NCM samples at a cut-off voltage of 4.3V. The results of the CV and EIS test showed that the additional graphite could slow down the increase of electrochemical polarization. In conclusion, the rate capability and cycling performance of the modified NCM were improved.