Hailong Chen

Publications (2)19.81 Total impact

• Source

  Available from: Geoffroy Hautier

  Article: Synthesis, computed stability and crystal structure of a new family of inorganic compounds: Carbonophosphates.

  Hailong Chen, Geoffroy Hautier, Gerbrand Ceder
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  ABSTRACT: Ab initio based high-throughput computing and screening have begun to be used to search and predict new functional materials and novel compounds(1-5). However, systematical experimental validation on the predictions remains highly challenging yet desired. Careful comparison between computational predictions and experimental results is sparse in the literature. Here we report on a systematical experimental validation on previously presented computational predictions of a novel alkali-carbonophosphate family of compounds(6). We report the successful hydrothermal synthesis and structural characterization of multiple Na-carbonophosphates. The experimental formation conditions of the carbonophosphates and the computational results are compared and discussed. We also demonstrate topotactic chemical desodiation of one of the compounds indicating the potential of this novel class of compounds as Li(+) or Na(+) insertion electrodes.
  Journal of the American Chemical Society 10/2012; · 9.91 Impact Factor
• Article: Electronic spin transition in nanosize stoichiometric lithium cobalt oxide.

  Danna Qian, Yoyo Hinuma, Hailong Chen, Lin-Shu Du, Kyler J Carroll, Gerbrand Ceder, Clare P Grey, Ying S Meng
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  ABSTRACT: A change in the electronic spin state of the surfaces relevant to Li (de)intercalation of nanosized stoichiometric lithium cobalt oxide LiCo(III)O(2) from low-spin to intermediate and high spin is observed for the first time. These surfaces are the ones that are relevant for Li (de)intercalation. From density functional theory calculations with a Hubbard U correction, the surface energies of the layered lithium cobalt oxide can be significantly lowered as a consequence of the spin change. The crystal field splitting of Co d orbitals is modified at the surface due to missing Co-O bonds. The electronic spin transition also has a significant impact on Co(III)-Co(IV) redox potential, as revealed by the change in the lithium (de)intercalation voltage profile in a lithium half cell.
  Journal of the American Chemical Society 03/2012; 134(14):6096-9. · 9.91 Impact Factor