Outstanding Electrochemical Performance of Ni-Rich Concentration-Gradient Cathode Material LiNi0.9Co0.083Mn0.017O2 for Lithium-Ion Batteries

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 8; p. 3347
• Main Authors: Li, Hechen, Guo, Yiwen, Chen, Yuanhua, Gao, Nengshuang, Sun, Ruicong, Lu, Yachun, Chen, Quanqi
• Format: Journal Article
• Language: English
• Published: MDPI 10.04.2023; MDPI AG
• Subjects: cathode materials; concentration-gradient; lithium-ion batteries; Ni-rich ternary
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28083347

The full-concentrationgradient LiNi0.9Co0.083Mn0.017O2 (CG-LNCM), consisting of core Ni-rich LiNi0.93Co0.07O2, transition zone LiNi1−x−yCoxMnyO2, and outmost shell LiNi1/3Co1/3Mn1/3O2 was prepared by a facile co-precipitation method and high-temperature calcination. CG-LNCM was then investigated with an X-ray diffractometer, ascanning electron microscope, a transmission electron microscope, and electrochemical measurements. The results demonstrate that CG-LNCM has a lower cation mixing of Li+ and Ni2+ and larger Li+ diffusion coefficients than concentration-constant LiNi0.9Co0.083Mn0.017O2 (CC-LNCM). CG-LNCM presents a higher capacity and a better rate of capability and cyclability than CC-LNCM. CG-LNCM and CC-LNCM show initial discharge capacities of 221.2 and 212.5 mAh g−1 at 0.2C (40 mA g−1) with corresponding residual discharge capacities of 177.3 and 156.1 mAh g−1 after 80 cycles, respectively. Even at high current rates of 2C and 5C, CG-LNCM exhibits high discharge capacities of 165.1 and 149.1 mAh g−1 after 100 cycles, respectively, while the residual discharge capacities of CC-LNCM are as low as 148.8 and 117.9 mAh g−1 at 2C and 5C after 100 cycles, respectively. The significantly improved electrochemical performance of CG-LNCM is attributed to its concentration-gradient microstructure and the composition distribution of concentration-gradient LiNi0.9Co0.083Mn0.017O2. The special concentration-gradient design and the facile synthesis are favorable for massive manufacturing of high-performance Ni-rich ternary cathode materials for lithium-ion batteries.