In:
Dalton Transactions, Royal Society of Chemistry (RSC), Vol. 50, No. 40 ( 2021), p. 14187-14195
Abstract:
Ni-rich LiNi 0.8 Co 0.15 Al 0.05 O 2 materials have been successfully applied in electric vehicles due to the merits of high energy density which can meet the requirements for driving range. Nevertheless, the electrochemical performances of Ni-rich materials are limited by their structural instability. Herein, LiNi 0.8 Co 0.15 Al 0.05 O 2 materials with the concentration-gradient structure of a Ni-rich core and a Co-rich surface were synthesized. The electrochemical results indicate that surface-concentration gradient LiNi 0.8 Co 0.15 Al 0.05 O 2 provides improved electrochemical performance. It not only displays an initial Coulomb efficiency of 82.4%, and a capacity retention of 80.37% after 200 cycles at 25 °C, but also shows a capacity retention of 77.76% after 150 cycles at a high temperature of 55 °C. These excellent performances can be attributed to adjusting the distribution of Ni on the surface of the LiNi 0.8 Co 0.15 Al 0.05 O 2 material, which inhibits the interfacial reaction between the material surface and electrolyte, lowers the consumption of active Li + and decreases the interfacial film impedance. Moreover, less Ni content on the material surface is beneficial for reducing the formation of a NiO rock salt phase during the charging process and inhibits the surface structural evolution. The proposed method and detected mechanism will provide guidance for the design of cathode materials and their practical industrial applications.
Type of Medium:
Online Resource
ISSN:
1477-9226
,
1477-9234
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
1472887-4
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