Effect of Niobium Doping on Structural Stability and Electrochemical Properties of LiNiO2 Cathode for Li-Ion Batteries. Issue 4 (1st April 2022)

• Record Type: Journal Article
• Authors: Huang, Guo-Xin; Wang, Ruo-Heng; Lv, Xiao-Yan; Su, Jing; Long, Yun-Fei; Qin, Zu-Zeng; Wen, Yan-Xuan
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 4(2022)
• Publication Date: 2022-04-01
• Subjects: Lithium ion batteries -- Cathode -- Lithium nickelate -- Niobium doping.; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac653e
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : LiNiO2, a promising cobalt-free cathode, suffers from poor cyclic stability and inferior rate performance due to structural degradation. A strategy based on the synergistic effect of a strong Nb–O bond (753 kJ mol −1 ), high valence state (Nb 5+ ), and larger ionic radius (0.64 Å) was developed to improve the properties of LiNiO2 . The synergistic effects can effectively improve lattice stability, lower Li + /Ni 2+ cation mixing, expand LiO6 -slab spaces, enhance the conductivity and inhibit the H2–H3 phase transition, which can enhance the stability of the layered structure, accelerate Li + diffusion and alleviate mechanical damage. Therefore, LiN0.99 Nb0.01 O2 exhibits higher capacity retention (91.4% after 100 cycles at 0.5C) and superior rate capability (143 mAh g −1 at 5C). As a comparison, the data of bare LiNiO2 is 69.2% and 127 mAh g −1 under the same conditions. These results further demonstrate the effectiveness of the proposed doping strategy.