Improvement in interfacial stability of high-rate Ni-rich oxide cathode by multifunctional LiTi0.5Zr1.5(PO4)3 conductive buffer layer

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 448; p. 137663
• Main Authors: Luo, Shijian, Yang, Fenghua, Xiong, Zilong, Wu, Yunlong, Ao, Xianquan, Li, Cuiqin, Chen, Qianlin, Wang, Keliang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2022
• Subjects: Conductive buffer layer; DFT calculation; Interface stability; Ni-rich oxide cathode; Superior rate ability; Surface modification; Superior rate ability; Surface modification; DFT calculation; Interface stability; Ni-rich oxide cathode; Conductive buffer layer
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.137663

[Display omitted] •Innovative construction of a multifunctional LTZP buffer layer is introduced.•Ti4+/Zr4+ is doped into NCM811 bulk structure, while LTZP layer is coated on surface.•LTZP stabilizes structure, avoids corrosion, and inhibits release of lattice oxygen.•Excellent rate capability, and long-term cycle of NCM-LTZP1 is demonstrated. With the advent of the double carbon era, Ni-rich layered oxides with high energy density have become ideal cathode materials to support and secure the energy transition of basic power and transportation. However, with the increase in Ni content, Ni-rich layered oxides suffer from several problems, such as difficult precursor synthesis, structural instability, and high interfacial activity. In this study, a design scheme of uniformly coating LiTi0.5Zr1.5(PO4)3 (LTZP) conductive buffer layer on the outer surface of LiNi0.8Mn0.1Co0.1O2 (NCM811) grains was proposed to overcome the above problems. The results of first-principles calculations and various ex-situ characterizations showed that the NASICON-type LTZP material had excellent compatibility with the NCM811 material. The LTZP surface-modified NCM811cathode material presented outstanding electrochemical performance. The initial discharge specific capacity was 210.16 mAh g−1 at 0.2C, and a remarkably high discharge capacity of 147.68 mAh g−1 was recorded at 10C. The capacity retention rate reached 84.7% after 200 cycles of 1C (25 °C). This work presents a strategy for stabilizing the interface with a conductive buffer layer to enhance the electrochemical performance of Ni-rich cathode materials.