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Uniform Ni-rich LiNi0.6Co0.2Mn0.2O2 porous microspheres: facile designed synthesis and their improved electrochemical performance

Journal Article


Abstract


  • A facile two-step synthetic route, i.e., combining the carbonate co-precipitation method and impregnation method, to prepare uniform porous Ni-rich LiNi0.6Co0.2Mn0.2O2 microsphere with an average diameter of ∼3 μm and BET specific surface area of 13.4 m2 g-1 is proposed for the first time. The XRD and TEM results confirm that the porous microspheres LiNi0.6Co0.2Mn0.2O2 material has a well-ordered α-NaFeO2 structure with stable in-plane [3×3]R30° ordering in the transition-metal layers. The exquisite morphology and ideal structure endow this nanocrystal-assembled porous LiNi0.6Co0.2Mn0.2O2 microspheres enhanced electrochemical performance such as high capacity, good cycling stability and excellent rate capability. Specifically, the as-prepared porous LiNi0.6Co0.2Mn0.2O2 cathode delivers a high discharge capacity of 79 mAh g-1 even at the ultrahigh rate 50C (10 A g-1), and 138 mAh g-1 at 1C after 100 cycles with an excellent cycle life. Additionally, the fast-charging test results are indicative of the fact that this cathode has sufficiently stable structure, because it can still deliver a discharge capacity higher than 123 mAh g-1 after 100 cycles with capacity retention of 90.1% at 5C charge and 1C discharge. The cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) results demonstrate that the porous LiNi0.6Co0.2Mn0.2O2 cathode has a higher apparent lithium ion diffusion coefficient (insertion/extraction process are 8.67 × 10-8 and 3.78 × 10-8 cm2 s-1, respectively) and lower activation energy (29.3 KJ mol-1). Our results indicate that this preparation strategy may be facile and versatile for synthesis other high-capacity anode/cathode materials.

Authors


  •   Zheng, Zhuo (external author)
  •   Guo, Xiaodong (external author)
  •   Chou, Shulei
  •   Hua, Wei-Bo (external author)
  •   Liu, Hua K.
  •   Dou, Shi Xue
  •   Yang, Xiu-Shan (external author)

Publication Date


  • 2016

Citation


  • Zheng, Z., Guo, X., Chou, S., Hua, W., Liu, H., Dou, S. Xue. & Yang, X. (2016). Uniform Ni-rich LiNi0.6Co0.2Mn0.2O2 porous microspheres: facile designed synthesis and their improved electrochemical performance. Electrochimica Acta, 191 401-410.

Scopus Eid


  • 2-s2.0-84955517379

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2061

Has Global Citation Frequency


Number Of Pages


  • 9

Start Page


  • 401

End Page


  • 410

Volume


  • 191

Place Of Publication


  • United Kingdom

Abstract


  • A facile two-step synthetic route, i.e., combining the carbonate co-precipitation method and impregnation method, to prepare uniform porous Ni-rich LiNi0.6Co0.2Mn0.2O2 microsphere with an average diameter of ∼3 μm and BET specific surface area of 13.4 m2 g-1 is proposed for the first time. The XRD and TEM results confirm that the porous microspheres LiNi0.6Co0.2Mn0.2O2 material has a well-ordered α-NaFeO2 structure with stable in-plane [3×3]R30° ordering in the transition-metal layers. The exquisite morphology and ideal structure endow this nanocrystal-assembled porous LiNi0.6Co0.2Mn0.2O2 microspheres enhanced electrochemical performance such as high capacity, good cycling stability and excellent rate capability. Specifically, the as-prepared porous LiNi0.6Co0.2Mn0.2O2 cathode delivers a high discharge capacity of 79 mAh g-1 even at the ultrahigh rate 50C (10 A g-1), and 138 mAh g-1 at 1C after 100 cycles with an excellent cycle life. Additionally, the fast-charging test results are indicative of the fact that this cathode has sufficiently stable structure, because it can still deliver a discharge capacity higher than 123 mAh g-1 after 100 cycles with capacity retention of 90.1% at 5C charge and 1C discharge. The cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) results demonstrate that the porous LiNi0.6Co0.2Mn0.2O2 cathode has a higher apparent lithium ion diffusion coefficient (insertion/extraction process are 8.67 × 10-8 and 3.78 × 10-8 cm2 s-1, respectively) and lower activation energy (29.3 KJ mol-1). Our results indicate that this preparation strategy may be facile and versatile for synthesis other high-capacity anode/cathode materials.

Authors


  •   Zheng, Zhuo (external author)
  •   Guo, Xiaodong (external author)
  •   Chou, Shulei
  •   Hua, Wei-Bo (external author)
  •   Liu, Hua K.
  •   Dou, Shi Xue
  •   Yang, Xiu-Shan (external author)

Publication Date


  • 2016

Citation


  • Zheng, Z., Guo, X., Chou, S., Hua, W., Liu, H., Dou, S. Xue. & Yang, X. (2016). Uniform Ni-rich LiNi0.6Co0.2Mn0.2O2 porous microspheres: facile designed synthesis and their improved electrochemical performance. Electrochimica Acta, 191 401-410.

Scopus Eid


  • 2-s2.0-84955517379

Ro Metadata Url


  • http://ro.uow.edu.au/aiimpapers/2061

Has Global Citation Frequency


Number Of Pages


  • 9

Start Page


  • 401

End Page


  • 410

Volume


  • 191

Place Of Publication


  • United Kingdom