Enhanced cycling stability of Sn-doped Li[Ni0.90Co0.05Mn0.05]O2 via optimization of particle shape and orientation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 405; p. 126887
• Main Authors: Thien Nguyen, Trung, Kim, Un-Hyuck, Yoon, Chong S., Sun, Yang-Kook
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2021
• Subjects: Crystallographic orientation; Crystallographic texture; Lithium-ion batteries; Microcrack suppression; Ni-rich cathode; Sn substitution; Lithium-ion batteries; Crystallographic orientation; Ni-rich cathode; Crystallographic texture; Sn substitution; Microcrack suppression
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.126887

[Display omitted] •Sn-doped Ni-rich NCM (Sn-NCM90) has radially oriented thin primary particles.•The substitution of Ni by Sn is a promising method in achieving optimal microstructure.•The Sn-NCM90 particles contract uniformly and suppress microcrack formation.•The Sn-NCM90 guaranteed stable electrochemical performance. Ni-rich Li[NixCoyMn1−x−y]O2 (x ≥ 0.8) cathodes suffer from structural degradation and capacity fading owing to the microcracks generated by abrupt volume contraction in the deeply charged state. To resolve this problem, the substitution of Ni by Sn in Li[Ni0.90Co0.05Mn0.05]O2 is proposed. Li[Ni0.897Co0.05Mn0.05Sn0.003]O2 (Sn-NCM90) has a unique microstructure in which the primary particles are oriented along the radial direction. This radial alignment, combined with the (001) crystallographic texture, suppresses microcrack formation and propagation by effectively relieving an internal strain in the deeply charged state. The microstructure-modified Sn-NCM90 cathode delivers a discharge capacity of 224.3 mAh g−1 and exhibits a capacity retention of 92.9% after 100 cycles at 4.3 V and 82.9% at 4.4 V. The proposed Sn substitution method shows that appropriate microstructural modification of the cathode can improve the cycling stability of Ni-rich layered cathodes.