Effects of Nb substitution on structure and electrochemical properties of LiNi0.7Mn0.3O2 cathode materials
- 101 Downloads
Nb-doped cathode materials with the formula Li(Ni0.7Mn0.3)1−xNbxO2 (x = 0, 0.01, 0.02, 0.03, 0.04) have been prepared successfully by calcining the mixtures of LiOH·H2O, Nb2O5, and Ni0.7Mn0.3(OH)2 precursor formed through a simple continuous co-precipitation method. The effects of Nb substitution on the crystal structure and electrochemical properties of LiNi0.7Mn0.3O2 were studied systematically by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and various electrochemical measurements. The results show that the lattice parameters of the Nb substitution LiNi0.7Mn0.3O2 samples are slightly larger than that of pure LiNi0.7Mn0.3O2, and the basic α-NaFeO2 layered structure does not change with the Nb doping. What’s more, better morphology, lower resistance, and good cycle stability were obtained after Nb substitution. In addition, CV test exhibits that Nb doping results in lower electrode polarization and XPS results indicate that the valence of Mn kept constant but the component of Ni3+ decreased after doping. All the results indicate that Nb doping in LiNi0.7Mn0.3O2 is a promising method to improve the properties of Ni-rich lithium-ion batteries positive-electrode materials.
KeywordsLithium-ion batteries Ni-rich positive-electrode materials Niobium doping Electrochemical properties
This work received financial support from the National Natural Science Fund of China (No. 51372104), Jiangxi Province Science and Technology Plan Project (grant nos. 20141BBE50019, 20151BBE50106), Youth science fund program of Jiangxi science and technology bureau (grant no. 2010GQC0064), and Jiangxi Provincial Education Office Natural Science Fund Project (GJJ170510).
- 6.Hwang S, Kim SM, Bak SM, Kim SY, Cho BW, Chung KY, Lee JY, Stach EA, Chang WY (2015) Using real-time electron microscopy to explore the effects of transition-metal composition on the local thermal stability in charged LixNiyMnzCo1-y-zO2 Cathode Materials. Chem Mater 27(11):3927–3935CrossRefGoogle Scholar
- 11.Bak SM, Hu E, Zhou Y, Yu X, Senanayake SD, Cho SJ, Kim KB, Chung KY, Yang XC (2014) Structural changes and thermal stability of charged LiNixMnyCozO2 cathode materials studied by combined in situ time-resolved XRD and mass spectroscopy. Acs Appl Mater Interfaces 6(24):22594–22601CrossRefGoogle Scholar
- 15.Schipper F, Dixit M, Kovacheva D, Talianker M, Haik O, Grinblat J, Erickson EM, Ghanty C, Major DT, Markovsky B, Aurbach D (2016) Stabilizing nickel-rich layered cathode materials by a high-charge cation doping strategy: zirconium-doped LiNi0.6Co0.2Mn0.2O2. J Mater Chem A 4(41):16073–16084CrossRefGoogle Scholar
- 35.Zhen C, Jin W, Chao DL, Baikie T, Bai LY, Chen S, Zhao YL, Sum TC, Lin JY, Shen ZX (2016) Hierarchical porous LiNi1/3Co1/3Mn1/3O2 nano-/micro spherical cathode material: minimized cation mixing and improved Li+ mobility for enhanced electrochemical performance. Sci Rep 6:25771–25780CrossRefGoogle Scholar