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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.

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FTIR spectra of(a) the ordered LiNi0.5Mn1.5O4 nanorods and (b) the disordered LiNi0.5Mn1.5O4 powder prepared by a solid state synthesis.
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f4: FTIR spectra of(a) the ordered LiNi0.5Mn1.5O4 nanorods and (b) the disordered LiNi0.5Mn1.5O4 powder prepared by a solid state synthesis.

Mentions: To further confirm the structural symmetry of the spinel in the present work, FTIR analysis was carried out on different spinel powder samples. For comparison, disordered LiNi0.5Mn1.5O4 powders were prepared by a solid state synthesis according to the literature26. Figure 4a,b show the FTIR spectra of the as-prepared LiNi0.5Mn1.5O4 nanorods and the LiNi0.5Mn1.5O4 powders prepared by solid state synthesis, respectively. There are eight distinctive bands for the as-prepared LiNi0.5Mn1.5O4 nanorods, and the observed wavenumbers match well with those of ordered spinel in literature823. By contrast, some bands are not well resolved for the disordered LiNi0.5Mn1.5O4 because of lacking of Ni/Mn ordering. Another evidence to distinguish the two structures is the change of the intensity ratio of the two bands at 622 and 584 cm−1. In specific, the 584 cm−1 Ni-O band increases in intensity compared to the 622 cm−1 Mn-O band with increasing level of ordering8. Agreeing well with Raman analysis, the FTIR analysis confirms that the as-prepared LiNi0.5Mn1.5O4 nanorods have ordered spinel structure with P4332 symmetry.


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)

FTIR spectra of(a) the ordered LiNi0.5Mn1.5O4 nanorods and (b) the disordered LiNi0.5Mn1.5O4 powder prepared by a solid state synthesis.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: FTIR spectra of(a) the ordered LiNi0.5Mn1.5O4 nanorods and (b) the disordered LiNi0.5Mn1.5O4 powder prepared by a solid state synthesis.
Mentions: To further confirm the structural symmetry of the spinel in the present work, FTIR analysis was carried out on different spinel powder samples. For comparison, disordered LiNi0.5Mn1.5O4 powders were prepared by a solid state synthesis according to the literature26. Figure 4a,b show the FTIR spectra of the as-prepared LiNi0.5Mn1.5O4 nanorods and the LiNi0.5Mn1.5O4 powders prepared by solid state synthesis, respectively. There are eight distinctive bands for the as-prepared LiNi0.5Mn1.5O4 nanorods, and the observed wavenumbers match well with those of ordered spinel in literature823. By contrast, some bands are not well resolved for the disordered LiNi0.5Mn1.5O4 because of lacking of Ni/Mn ordering. Another evidence to distinguish the two structures is the change of the intensity ratio of the two bands at 622 and 584 cm−1. In specific, the 584 cm−1 Ni-O band increases in intensity compared to the 622 cm−1 Mn-O band with increasing level of ordering8. Agreeing well with Raman analysis, the FTIR analysis confirms that the as-prepared LiNi0.5Mn1.5O4 nanorods have ordered spinel structure with P4332 symmetry.

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