Limits...
Graphene wrapped ordered LiNi0.5Mn1.5O4 nanorods as promising cathode material for lithium-ion batteries.

Tang X, Jan SS, Qian Y, Xia H, Ni J, Savilov SV, Aldoshin SM - Sci Rep (2015)

Bottom Line: The morphological characterization by scanning electron microscopy and transmission electron microscopy reveals that the LiNi0.5Mn1.5O4 nanorods of 100-200 nm in diameter are well dispersed and wrapped in the graphene nanosheets for the composite.Benefiting from the highly conductive matrix provided by graphene nanosheets and one-dimensional nanostructure of the ordered spinel, the composite electrode exhibits superior rate capability and cycling stability.As a result, the LiNi0.5Mn1.5O4-graphene composite electrode delivers reversible capacities of 127.6 and 80.8 mAh g(-1) at 0.1 and 10 C, respectively, and shows 94% capacity retention after 200 cycles at 1 C, greatly outperforming the bare LiNi0.5Mn1.5O4 nanorod cathode.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China [2] Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China.

ABSTRACT
LiNi0.5Mn1.5O4 nanorods wrapped with graphene nanosheets have been prepared and investigated as high energy and high power cathode material for lithium-ion batteries. The structural characterization by X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy indicates the LiNi0.5Mn1.5O4 nanorods prepared from β-MnO2 nanowires have ordered spinel structure with P4332 space group. The morphological characterization by scanning electron microscopy and transmission electron microscopy reveals that the LiNi0.5Mn1.5O4 nanorods of 100-200 nm in diameter are well dispersed and wrapped in the graphene nanosheets for the composite. Benefiting from the highly conductive matrix provided by graphene nanosheets and one-dimensional nanostructure of the ordered spinel, the composite electrode exhibits superior rate capability and cycling stability. As a result, the LiNi0.5Mn1.5O4-graphene composite electrode delivers reversible capacities of 127.6 and 80.8 mAh g(-1) at 0.1 and 10 C, respectively, and shows 94% capacity retention after 200 cycles at 1 C, greatly outperforming the bare LiNi0.5Mn1.5O4 nanorod cathode. The outstanding performance of the LiNi0.5Mn1.5O4-graphene composite makes it promising as cathode material for developing high energy and high power lithium-ion batteries.

No MeSH data available.


Related in: MedlinePlus

XRD patterns of the pristine graphene nanosheets, the as-synthesized LiNi0.5Mn1.5O4 nanorods, and the LiNi0.5Mn1.5O4-graphene composite.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4493710&req=5

f2: XRD patterns of the pristine graphene nanosheets, the as-synthesized LiNi0.5Mn1.5O4 nanorods, and the LiNi0.5Mn1.5O4-graphene composite.

Mentions: The hydrothermally prepared β-MnO2 nanowires were used as the template and the XRD pattern shows no trace of impurity (Fig. S1, Supporting Information). Figure 2 shows the XRD patterns of the pristine graphene nanosheets, the as-synthesized LiNi0.5Mn1.5O4 nanorods, and the LiNi0.5Mn1.5O4-graphene composite. The XRD pattern of the graphene shows a small hump at about 26°, which can be attributed to the (002) reflection of graphite. The as-synthesized LiNi0.5Mn1.5O4 nanorods and the LiNi0.5Mn1.5O4-graphene composite show similar XRD patterns, which can be indexed to the cubic spinel structure with space group P4332 (JCPDS No. 80-2184). No impurity peaks from NiO or LixNiyO can be detected, indicating the existence of pure spinel phase. Rietveld refinement gives a lattice parameter of a = 8.169 Å, which agrees well with reported value for the ordered LiNi0.5Mn1.5O41213. No diffraction peaks of graphene can be observed from the XRD pattern of the LiNi0.5Mn1.5O4-graphene composite, which is probably due to the strong diffraction peaks from the highly crystalline LiNi0.5Mn1.5O4 and the nanoscale size feature of low content graphene. However, the superstructure peaks, which are characteristics of Ni and Mn ordering, cannot be resolved from the XRD patterns of the spinels because of their low intensities23. Therefore, further structural investigation by Raman and FTIR are required to confirm the P4332 symmetry of the synthesized spinel in this work.


Graphene wrapped ordered LiNi0.5Mn1.5O4 nanorods as promising cathode material for lithium-ion batteries.

Tang X, Jan SS, Qian Y, Xia H, Ni J, Savilov SV, Aldoshin SM - Sci Rep (2015)

XRD patterns of the pristine graphene nanosheets, the as-synthesized LiNi0.5Mn1.5O4 nanorods, and the LiNi0.5Mn1.5O4-graphene composite.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493710&req=5

f2: XRD patterns of the pristine graphene nanosheets, the as-synthesized LiNi0.5Mn1.5O4 nanorods, and the LiNi0.5Mn1.5O4-graphene composite.
Mentions: The hydrothermally prepared β-MnO2 nanowires were used as the template and the XRD pattern shows no trace of impurity (Fig. S1, Supporting Information). Figure 2 shows the XRD patterns of the pristine graphene nanosheets, the as-synthesized LiNi0.5Mn1.5O4 nanorods, and the LiNi0.5Mn1.5O4-graphene composite. The XRD pattern of the graphene shows a small hump at about 26°, which can be attributed to the (002) reflection of graphite. The as-synthesized LiNi0.5Mn1.5O4 nanorods and the LiNi0.5Mn1.5O4-graphene composite show similar XRD patterns, which can be indexed to the cubic spinel structure with space group P4332 (JCPDS No. 80-2184). No impurity peaks from NiO or LixNiyO can be detected, indicating the existence of pure spinel phase. Rietveld refinement gives a lattice parameter of a = 8.169 Å, which agrees well with reported value for the ordered LiNi0.5Mn1.5O41213. No diffraction peaks of graphene can be observed from the XRD pattern of the LiNi0.5Mn1.5O4-graphene composite, which is probably due to the strong diffraction peaks from the highly crystalline LiNi0.5Mn1.5O4 and the nanoscale size feature of low content graphene. However, the superstructure peaks, which are characteristics of Ni and Mn ordering, cannot be resolved from the XRD patterns of the spinels because of their low intensities23. Therefore, further structural investigation by Raman and FTIR are required to confirm the P4332 symmetry of the synthesized spinel in this work.

Bottom Line: The morphological characterization by scanning electron microscopy and transmission electron microscopy reveals that the LiNi0.5Mn1.5O4 nanorods of 100-200 nm in diameter are well dispersed and wrapped in the graphene nanosheets for the composite.Benefiting from the highly conductive matrix provided by graphene nanosheets and one-dimensional nanostructure of the ordered spinel, the composite electrode exhibits superior rate capability and cycling stability.As a result, the LiNi0.5Mn1.5O4-graphene composite electrode delivers reversible capacities of 127.6 and 80.8 mAh g(-1) at 0.1 and 10 C, respectively, and shows 94% capacity retention after 200 cycles at 1 C, greatly outperforming the bare LiNi0.5Mn1.5O4 nanorod cathode.

View Article: PubMed Central - PubMed

Affiliation: 1] School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China [2] Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing 210094, China.

ABSTRACT
LiNi0.5Mn1.5O4 nanorods wrapped with graphene nanosheets have been prepared and investigated as high energy and high power cathode material for lithium-ion batteries. The structural characterization by X-ray diffraction, Raman spectroscopy, and Fourier transform infrared spectroscopy indicates the LiNi0.5Mn1.5O4 nanorods prepared from β-MnO2 nanowires have ordered spinel structure with P4332 space group. The morphological characterization by scanning electron microscopy and transmission electron microscopy reveals that the LiNi0.5Mn1.5O4 nanorods of 100-200 nm in diameter are well dispersed and wrapped in the graphene nanosheets for the composite. Benefiting from the highly conductive matrix provided by graphene nanosheets and one-dimensional nanostructure of the ordered spinel, the composite electrode exhibits superior rate capability and cycling stability. As a result, the LiNi0.5Mn1.5O4-graphene composite electrode delivers reversible capacities of 127.6 and 80.8 mAh g(-1) at 0.1 and 10 C, respectively, and shows 94% capacity retention after 200 cycles at 1 C, greatly outperforming the bare LiNi0.5Mn1.5O4 nanorod cathode. The outstanding performance of the LiNi0.5Mn1.5O4-graphene composite makes it promising as cathode material for developing high energy and high power lithium-ion batteries.

No MeSH data available.


Related in: MedlinePlus