| 초록 |
Recently, Ni-riched cathode material is mainly used as the large-scale power sources, such as EV, HEV and ESS, etc, due to its low cost and high capacities. However, it has some problems, such as lower thermal stability, poor cycling performance, and increased impedance during cycling. In order to solve these problems, doping and/or surface treatment have been employed. In this study, boron was selected as a doping element onto Li1.06Ni0.91Co0.08Al0.01O2 (B-NCA) to improve its cycling performance. Also, LiCoO2 (LCO) layer was coated onto the surface of NCA powders (LCO-NCA) to improve its coulomb efficiency. The crystalline and morphological structures were analyzed by using XRD methode and FE-SEM. For investigation of electrochemical properties as the cathode material of battery, the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and cycling performance were investigated. As a result, the discharge capacities of pure NCA, B-NCA, and LCO-NCA based lithium ion batteries exhibited 193, 214, and 200 mAh g-1 at the first cycle, respectively, and the higher coulomb efficiency (＞90%) was obtained in LCO-NCA based lithium ion battery. |
