Surface Modified Copper Improves the Electrochemical Performance of LiNi0.5Co0.2Mn0.3O2 Cathode Material

The application of LiNi0.5Co0.2Mn0.3O2 is still hindered by its low capacity retention rate and poor high rate performance. The surface coating has proven to be an effective strategy to solve these problems. However, the previous surface coating method will make the synthesis process more complicated. In this work, a simple organic salt decomposition method is developed to prepare LiNi0.5Co0.2Mn0.3O2@Cu cathode material (NCM@Cu). The results of the scanning electron microscope (SEM), X-ray diffractometer (XRD), and energy X-ray spectroscopy (EDS) have confirmed that a uniform copper-coated composite structure has been successfully constructed without changing the crystal structure. Charge and discharge tests show that the irreversible capacity loss of NCM@Cu at 0.2 C is 33.8 mA h g–1, which is lower than NCM. Compared with bare NCM, the composite cathode NCM@Cu has better cycle performance. This improvement is attributed to the coating of the copper element, which increases surface electron transport.