Radially Oriented Single‐Crystal Primary Nanosheets Enable Ultrahigh Rate and Cycling Properties of LiNi0.8Co0.1Mn0.1O2 Cathode Material for Lithium‐Ion Batteries

• Published in: Advanced energy materials Vol. 9; no. 15
• Main Authors: Xu, Xing, Huo, Hua, Jian, Jiyuan, Wang, Liguang, Zhu, He, Xu, Sheng, He, Xiaoshu, Yin, Geping, Du, Chunyu, Sun, Xueliang
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 18.04.2019
• Subjects: anisotropic property; Anisotropy; Cathodes; Crystal structure; Crystallography; Cycles; Diffusion coefficient; Electrode materials; Ion diffusion; Lithium; Lithium-ion batteries; Morphology; Nanosheets; Ni‐rich layered oxides; radial arrangement
• DOI: 10.1002/aenm.201803963
• ISSN: 1614-6832

Ni‐rich Li[NixCoyMn1−x−y]O2 (x ≥ 0.8) layered oxides are the most promising cathode materials for lithium‐ion batteries due to their high reversible capacity of over 200 mAh g−1. Unfortunately, the anisotropic properties associated with the α‐NaFeO2 structured crystal grains result in poor rate capability and insufficient cycle life. To address these issues, a micrometer‐sized Ni‐rich LiNi0.8Co0.1Mn0.1O2 secondary cathode material consisting of radially aligned single‐crystal primary particles is proposed and synthesized. Concomitant with this unique crystallographic texture, all the exposed surfaces are active {010} facets, and 3D Li+ ion diffusion channels penetrate straightforwardly from surface to center, remarkably improving the Li+ diffusion coefficient. Moreover, coordinated charge–discharge volume change upon cycling is achieved by the consistent crystal orientation, significantly alleviating the volume‐change‐induced intergrain stress. Accordingly, this material delivers superior reversible capacity (203.4 mAh g−1 at 3.0–4.3 V) and rate capability (152.7 mAh g−1 at a current density of 1000 mA g−1). Further, this structure demonstrates excellent cycling stability without any degradation after 300 cycles. The anisotropic morphology modulation provides a simple, efficient, and scalable way to boost the performance and applicability of Ni‐rich layered oxide cathode materials. A Ni‐rich LiNi0.8Co0.1Mn0.1O2 cathode material with radially aligned single‐crystal primary particles is synthesized. This unique crystallographic texture enables three‐dimensional (3D) Li+ diffusion channels penetrated straightforwardly from surface to center of the secondary particles and significantly alleviates volume‐change‐induced intergrain stress upon cycling. Accordingly, this material delivers superior capacity, rate capability and excellent cycling stability.