Conflicting roles of nickel in controlling cathode performance in lithium ion batteries

Meng Gu, Ilias Belharouak, Arda Genc, Zhiguo Wang, Dapeng Wang, Khalil Amine, Fei Gao, Guangwen Zhou, Suntharampillai Thevuthasan, Donald R. Baer, Ji Guang Zhang, Nigel D. Browning, Jun Liu, Chongmin Wang

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161 Citations (Scopus)

Abstract

A variety of approaches are being made to enhance the performance of lithium ion batteries. Incorporating multivalence transition-metal ions into metal oxide cathodes has been identified as an essential approach to achieve the necessary high voltage and high capacity. However, the fundamental mechanism that limits their power rate and cycling stability remains unclear. The power rate strongly depends on the lithium ion drift speed in the cathode. Crystallographically, these transition-metal-based cathodes frequently have a layered structure. In the classic wisdom, it is accepted that lithium ion travels swiftly within the layers moving out/in of the cathode during the charge/discharge. Here, we report the unexpected discovery of a thermodynamically driven, yet kinetically controlled, surface modification in the widely explored lithium nickel manganese oxide cathode material, which may inhibit the battery charge/discharge rate. We found that during cathode synthesis and processing before electrochemical cycling in the cell nickel can preferentially move along the fast diffusion channels and selectively segregate at the surface facets terminated with a mix of anions and cations. This segregation essentially can lead to a higher lithium diffusion barrier near the surface region of the particle. Therefore, it appears that the transition-metal dopant may help to provide high capacity and/or high voltage but can be located in a "wrong" location that may slow down lithium diffusion, limiting battery performance. In this circumstance, limitations in the properties of lithium ion batteries using these cathode materials can be determined more by the materials synthesis issues than by the operation within the battery itself.

Original languageEnglish
Pages (from-to)5186-5191
Number of pages6
JournalNano Letters
Volume12
Issue number10
DOIs
Publication statusPublished - 10 Oct 2012
Externally publishedYes

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Keywords

  • DFT calculation
  • Li Ni Mn O
  • lithium diffusion barrier
  • Lithium ion battery
  • nickel segregation
  • STEM

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanical Engineering

Cite this

Gu, M., Belharouak, I., Genc, A., Wang, Z., Wang, D., Amine, K., Gao, F., Zhou, G., Thevuthasan, S., Baer, D. R., Zhang, J. G., Browning, N. D., Liu, J., & Wang, C. (2012). Conflicting roles of nickel in controlling cathode performance in lithium ion batteries. Nano Letters, 12(10), 5186-5191. https://doi.org/10.1021/nl302249v