Extending Cycle Life of Li-Ion Batteries Via Gas-Phase Nanocoating of Cathode Active Materials

Abstract

The further penetration of the electric vehicles is dependent on the development of high-performance Li-ion batteries in terms of cost, cycle life, energy density, safety as well as sustainability. It is expected, in the short term, EVs will rely more on Li-ion technologies using active materials such as Ni-rich NMC cathode and Si anode for developing high specific energy and lower cost batteries1.However, these active materials are facing multiple serious challenges which could hinder their targeted performance. Regarding this, Ni-rich NMC cathode active materials (CAM), in spite of their high energy density as a result of higher Ni content, tend to undergo dramatic capacity fade. Since most degradation mechanisms are related to the surface of active materials, immense research and development efforts have been dedicated to surface modification techniques, and especially coating strategies2,3.Examples of surface modification strategies include sol-gel, hydro/solvothermal deposition, and dry coating. A main drawback of these techniques is that they are not capable of precise control of the film thickness and uniformity. On the other hand, gas-phase coating techniques, such as atomic or molecular layer deposition, can address these shortcomings by offering a precise thickness control even in the range of angstroms and pinhole-free conformal coatings. As such, these coatings are better suited at mitigating interfacial degradation. Various nanocoating chemistries, such as oxides, fluorides, nitrides, phosphates and aluminates protect and stabilize the surface of Ni-rich cathode materials through the different pathways. In this talk, we explore the benefits of gas-phase nanocoatings, and will show how we can produce surface modified Ni-rich CAM (e.g. NMC-811) in a continuous process that is ready for mass production. References M. S. E. Houache, C. H. Yim, Z. Karkar, and Y. Abu-Lebdeh, Batteries, 8 (2022).D. Weber, Đ. Tripković, K. Kretschmer, M. Bianchini, and T. Brezesinski, Eur. J. Inorg. Chem., 2020, 3117–3130 (2020).M. Lee et al., Chem. Mater., 34, 3539–3587 (2022).Y. Zhao, K. Zheng, and X. Sun, Joule, 2, 2583–2604 (2018).