High-quality LiNi0.8Co0.15Al0.05O2 cathode with excellent structural stability: Suppressed structural degradation and pore defects generation. (July 2020)

• Record Type: Journal Article
• Authors: Gao, Tian-Peng; Wong, Ka Wai; Ng, Ka Ming
• Is Part Of: Nano energy. Volume 73(2020)
• Publication Date: 2020-07
• Subjects: LiNi0.8Co0.15Al0.05O2 (NCA) -- Desired stoichiometric ratio -- {010} planes -- Structural degradation -- Pore defects; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2020.104798
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Although LiNi0.8 Co0.15 Al0.05 O2 (NCA) cathode materials have been widely used for electric vehicles, the poor cycle performance still limits the further application. In this work, high-quality NCA with desired stoichiometric ratio and few structural defects is prepared by using N-methyl-2-pyrrolidone (NMP)- and urea-based solvothermal reaction. The as-prepared NCA exhibits high capacity (203 mAh g −1 at 0.1 C), excellent rate capability (117 mAh g −1 at 10 C, attributed to enhanced exposure of {010} planes), and good cycle performance (74.4% capacity retention at 300th cycle). Compared with NCA prepared by NaOH, NCA prepared by NMP and urea shows superior ability in suppressing structural degradation of R 3 ‾ m phase-to- Fd 3 ‾ m/Fm 3 ‾ m phase transformation, transition metal segregation, and pore defects generation after prolonged cycling, which can be used for ultrafast and long-lifespan lithium storage. Graphical abstract: Image 1 Highlights: Hierarchical spherical precursor for NCA without Al deficiency is prepared by using urea-based solvothermal reaction. Owing to few structural defects and enhanced exposure of {010} planes, NCA shows excellent electrochemical performance. Structural degradation from R 3 ‾ m to Fd 3 ‾ m/Fm 3 ‾ m, transition metal segregation, and pore defects generation are suppressed.