Improving the electrochemical performance of a Cr-modified LiNi1/3Co1/3−xCrxMn1/3O2 cathode for lithium-ion batteries

• Published in: Materials research express Vol. 6; no. 9
• Main Authors: Yang, Li, Feng, Qigao, Ren, Fengzhang, Yan, Qinghua
• Format: Journal Article
• Language: English
• Published: IOP Publishing 02.08.2019
• Subjects: Cr doping of cathode materials; electrochemistry performance; sol-gel method; spent lithium-ion batteries
• ISSN: 2053-1591
• DOI: 10.1088/2053-1591/ab3476

In this report, Cr-modified LiNi1/3Co1/3-xCrxMn1/3O2 was prepared as the cathode for lithium-ion batteries through the sol-gel method using spent lithium-ion batteries as raw matrial, and Cr-modified LiNi1/3Co1/3−xCrxMn1/3O2 cathode exhibited better charge/discharge behaviors and cycling stability than the pristine LiNi1/3Co1/3Mn1/3O2. At 0.2 C, the first discharge capacities of Cr-modified LiNi1/3Co1/3−xCrxMn1/3O2 and pristine LiNi1/3Co1/3Mn1/3O2 were 156.8 mAh g−1 and 136.6 mAh g−1 with Coulomb efficiencies of 91% and 93%, respectively. The discharge capacities of Cr-modified LiNi1/3Co1/3−xCrxMn1/3O2 were 156.8, 151.5, and 145.3 mAh g−1, after 30 cycles at 0.2, 0.5, and 1.0 C, which were 91.5%, 90%, and 88% of their initial discharge capacities, respectively. The superior capacity and cycling performance indicate that the structure of Cr-modified LiNi1/3Co1/3−xCrxMn1/3O2 is very stable, and the results reveal that Cr ion doping effectively suppressed the degree of mixing of Li+/Ni2+ so that a limited amount of Li+ was blocked by Ni2+.