Concentration-Gradient LiNi0.85Co0.12Al0.03O2 Cathode Assembled with Primary Particles for Rechargeable Lithium-Ion Batteries

• Published in: Energy & fuels 2021-08, Vol.35 (16), p.13474-13482
• Main Authors: Zhang, Yudong, Liu, Jiuding, Cheng, Fangyi
• Format: Article
• Language: English
• Subjects: Batteries and Energy Storage
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.1c02115

Concentration-gradient structure design is a promising strategy to stabilize layered nickel-rich LiNi1–x–y Co x Al y O2 (NCA, 1 – x – y ≥ 0.8) cathode materials. However, the influence of the particle size on the properties of concentration-gradient NCA material has not been explored in detail. Here, we report the synthesis of concentration-gradient LiNi0.85Co0.12Al0.03O2 (CG-NCA) cathode microspheres assembled with different sizes of primary particles by adjusting the calcination temperature. The prepared CG-NCA assembled with 300–500 nm primary particles exhibits remarkable cyclic stability (capacity retention of 99.9% after 100 cycles at 1 C), high rate capability (145.6 mAh g–1 at 10 C), and thermal stability. The superior electrochemical performance is mainly attributed to the combination of the ordered layered structure and concentration-gradient distribution of Ni and Al in NCA. Small primary particles lead to a rapid impedance increase and severe side reactions, while large primary particles unfavor Li-ion diffusion. The results indicate the importance of primary particle size control in enhancing the performance of concentration-gradient Ni-rich cathode materials.