Tailoring the surface properties of LiNi0.4Mn0.4Co0.2O₂ by titanium substitution for improved high voltage cycling performance
The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4Mn0.4Co0.2O₂ (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher c...
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Published in | Physical chemistry chemical physics : PCCP Vol. 17; no. 34 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Royal Society of Chemistry
01.01.2015
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Subjects | |
Online Access | Get full text |
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Summary: | The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4Mn0.4Co0.2O₂ (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher capacities and exhibit better cycling stability than the unsubstituted compounds. It is found that NMC cathodes containing Ti show equivalent capacity fading but greater specific capacity than those without Ti in the same potential range. When repeatedly charged to the same degree of delithiation, NMC cathodes containing Ti showed better capacity retention. Soft x-ray absorption spectroscopy (XAS) spectra for Mn and Co indicated increased reduction in these elements for NMC cathodes without Ti, indicating that the substitution of Ti for Co acts to suppress the formation of a high impedance rock salt phase at the surface of NMC cathode particles. The results of this study validate the adoption of a facile change to existing NMC chemistries to improve cathode capacity retention under high voltage cycling conditions. |
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Bibliography: | USDOE Office of Science (SC), Basic Energy Sciences (BES) SC00112704 BNL-108310-2015-JA |
ISSN: | 1463-9076 1463-9084 |
DOI: | 10.1039/c5cp03228h |