Li0.33La0.56TiO3, a novel coating to improve the electrochemical properties and safety of NCM523 cathode materials for Li-ion batteries

• Published in: New journal of chemistry 2023-06, Vol.47 (23), p.11303-11311
• Main Authors: Heidari, Ehsan, Mohammad Amin Razmjoo Khollari, Soltani, Reza
• Format: Article
• Language: English
• Subjects: Cathodes; Cathodic coating (process); Cycles; Discharge; Electrochemical analysis; Electrode materials; Electrons; Industrial applications; Lithium-ion batteries; Rechargeable batteries; Safety; Structural stability
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d3nj01278f

There is an increasing demand for high energy density lithium-ion battery cathodes such as LiNi0.5Co0.2Mn0.3O2 (NCM523); however, severe capacity fading, and structural instability have limited their widespread application. In this study, the effect of surface modification with Li0.33La0.56TiO3 (LLTO) and its crystallinity on the electrochemical performance of NCM523 cathode materials was investigated. Scanning and transmission electron microscopy observation showed a uniform distribution of 3 and 5 wt% LLTO coating, but agglomeration was observed in a higher coating content. According to the electrochemical tests, the amorphous LLTO coating improved the cycling performance and rate capability of the NCM523 cathode. The 5 wt% amorphous LLTO-coated cathode showed the highest discharge capacity after 30 cycles at 0.1 C and after 100 cycles at 0.5 C (136.3 and 104.6 mA h g−1); significantly higher than that of the pristine NCM523 cathode (98.5 and 62.5 mA h g−1). The discharge capacity of this coated sample at 5 C was also much higher than that of the pristine cathode (106.8 compared to 78.5 mA h g−1). In addition, 5 wt% of the amorphous LLTO coating shifted the exothermic peak of the NCM523 electrode from 249 to 281 °C, indicating enhanced safety after the coating process. Compared to the crystalline LLTO-coated NCM523, the cathode with amorphous coating delivered a higher discharge capacity over cycling and at different C-rates. In light of the results, it is evident that surface modification with an amorphous LLTO coating could be a promising approach for industrial application of NCM523 cathode materials.