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Super high-rate, long cycle life of europium-modified, carbon-coated, hierarchical mesoporous lithium-titanate anode materials for lithium ion batteries

Journal Article


Abstract


  • Europium-modified, carbon-coated, hierarchical mesoporous Li4Ti5O12 microspheres were prepared via the co-precipitation method. X-ray diffraction (XRD) and Raman analyses revealed that europium ions were doped into 16d Li+/Ti4+ sites of Li4Ti5O12. Microscopic observations reveal that primary nanoparticles of Li4-x/2Ti5-x/2EuxO12@C (x = 0.004) are assembled into hierarchical mesoporous microspheres, with an average particle size of about 473.4 nm and a uniform particle size distribution. X-ray photoelectron spectroscopy demonstrated that partial Ti4+ is reduced to Ti3+ induced by carbon coating and double-valence state of europium (Eu2+/Eu3+) doping into the Li4Ti5O12. The samples exhibit excellent electrochemical properties including fast lithium storage performance, outstanding cycle stability and high rate capability. The highest initial discharge capacity of Li4-x/2Ti5-x/2EuxO12@C (x = 0.004) reached 198.7 mA h g-1 and the discharge capacity still maintained 173.4 mA h g-1 at 5C after 1000 cycles. Even cycled at 100C, the discharge capacity of Li4-x/2Ti5-x/2EuxO12@C (x = 0.004) maintained 92.1 mA h g-1. The excellent electrochemical performance can be attributed to the hierarchical mesoporous structure combined with modified strategies including europium doping and carbon coating, which not only improved the lithium-ion diffusion coefficient, but also increased the electronic conductivity. Moreover, the electrical conductivity between the Li4Ti5O12 particles was enhanced by carbon coating and the bulk electronic conductivity of Li4Ti5O12 was also improved by the presence of Ti3+.

Authors


  •   Cai, Yanjun (external author)
  •   Haung, Yudai (external author)
  •   Jia, Wei (external author)
  •   Wang, Xingchao (external author)
  •   Guo, Yong (external author)
  •   Jia, Dianzeng (external author)
  •   Sun, Zhipeng (external author)
  •   Pang, Wei Kong.
  •   Guo, Zaiping

Publication Date


  • 2016

Citation


  • Cai, Y., Huang, Y., Jia, W., Wang, X., Guo, Y., Jia, D., Sun, Z., Pang, W. & Guo, Z. (2016). Super high-rate, long cycle life of europium-modified, carbon-coated, hierarchical mesoporous lithium-titanate anode materials for lithium ion batteries. Journal of Materials Chemistry A, 4 (25), 9949-9957.

Scopus Eid


  • 2-s2.0-84976426707

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2198

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 9949

End Page


  • 9957

Volume


  • 4

Issue


  • 25

Place Of Publication


  • United Kingdom

Abstract


  • Europium-modified, carbon-coated, hierarchical mesoporous Li4Ti5O12 microspheres were prepared via the co-precipitation method. X-ray diffraction (XRD) and Raman analyses revealed that europium ions were doped into 16d Li+/Ti4+ sites of Li4Ti5O12. Microscopic observations reveal that primary nanoparticles of Li4-x/2Ti5-x/2EuxO12@C (x = 0.004) are assembled into hierarchical mesoporous microspheres, with an average particle size of about 473.4 nm and a uniform particle size distribution. X-ray photoelectron spectroscopy demonstrated that partial Ti4+ is reduced to Ti3+ induced by carbon coating and double-valence state of europium (Eu2+/Eu3+) doping into the Li4Ti5O12. The samples exhibit excellent electrochemical properties including fast lithium storage performance, outstanding cycle stability and high rate capability. The highest initial discharge capacity of Li4-x/2Ti5-x/2EuxO12@C (x = 0.004) reached 198.7 mA h g-1 and the discharge capacity still maintained 173.4 mA h g-1 at 5C after 1000 cycles. Even cycled at 100C, the discharge capacity of Li4-x/2Ti5-x/2EuxO12@C (x = 0.004) maintained 92.1 mA h g-1. The excellent electrochemical performance can be attributed to the hierarchical mesoporous structure combined with modified strategies including europium doping and carbon coating, which not only improved the lithium-ion diffusion coefficient, but also increased the electronic conductivity. Moreover, the electrical conductivity between the Li4Ti5O12 particles was enhanced by carbon coating and the bulk electronic conductivity of Li4Ti5O12 was also improved by the presence of Ti3+.

Authors


  •   Cai, Yanjun (external author)
  •   Haung, Yudai (external author)
  •   Jia, Wei (external author)
  •   Wang, Xingchao (external author)
  •   Guo, Yong (external author)
  •   Jia, Dianzeng (external author)
  •   Sun, Zhipeng (external author)
  •   Pang, Wei Kong.
  •   Guo, Zaiping

Publication Date


  • 2016

Citation


  • Cai, Y., Huang, Y., Jia, W., Wang, X., Guo, Y., Jia, D., Sun, Z., Pang, W. & Guo, Z. (2016). Super high-rate, long cycle life of europium-modified, carbon-coated, hierarchical mesoporous lithium-titanate anode materials for lithium ion batteries. Journal of Materials Chemistry A, 4 (25), 9949-9957.

Scopus Eid


  • 2-s2.0-84976426707

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2198

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 9949

End Page


  • 9957

Volume


  • 4

Issue


  • 25

Place Of Publication


  • United Kingdom