1
|
Hancock J, Griffith KJ, Choi Y, Bartel CJ, Lapidus SH, Vaughey JT, Ceder G, Poeppelmeier KR. Expanding the Ambient-Pressure Phase Space of CaFe 2O 4-Type Sodium Postspinel Host-Guest Compounds. ACS ORGANIC & INORGANIC AU 2021; 2:8-22. [PMID: 36855408 PMCID: PMC9954301 DOI: 10.1021/acsorginorgau.1c00019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
CaFe2O4-type sodium postspinels (Na-CFs), with Na+ occupying tunnel sites, are of interest as prospective battery electrodes. While many compounds of this structure type require high-pressure synthesis, several compounds are known to form at ambient pressure. Here we report a large expansion of the known Na-CF phase space at ambient pressure, having successfully synthesized NaCrTiO4, NaRhTiO4, NaCrSnO4, NaInSnO4, NaMg0.5Ti1.5O4, NaFe0.5Ti1.5O4, NaMg0.5Sn1.5O4, NaMn0.5Sn1.5O4, NaFe0.5Sn1.5O4, NaCo0.5Sn1.5O4, NaNi0.5Sn1.5O4, NaCu0.5Sn1.5O4, NaZn0.5Sn1.5O4, NaCd0.5Sn1.5O4, NaSc1.5Sb0.5O4, Na1.16In1.18Sb0.66O4, and several solid solutions. In contrast to earlier reports, even cations that are strongly Jahn-Teller active (e.g., Mn3+ and Cu2+) can form Na-CFs at ambient pressure when combined with Sn4+ rather than with the smaller Ti4+. Order and disorder are probed at the average and local length-scales with synchrotron powder X-ray diffraction and solid-state NMR spectroscopy. Strong ordering of framework cations between the two framework sites is not observed, except in the case of Na1.16In1.18Sb0.66O4. This compound is the first example of an Na-CF that contains Na+ in both the tunnel and framework sites, reminiscent of Li-rich spinels. Trends in the thermodynamic stability of the new compounds are explained on the basis of crystal-chemistry and density functional theory (DFT). Further DFT calculations examine the relative stability of the CF versus spinel structures at various degrees of sodium extraction in the context of electrochemical battery reactions.
Collapse
Affiliation(s)
- Justin
C. Hancock
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States,Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States
| | - Kent J. Griffith
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States,Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States
| | - Yunyeong Choi
- Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States,Department
of Materials Science and Engineering, University
of California, Berkeley, California 94720, United States
| | - Christopher J. Bartel
- Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States,Department
of Materials Science and Engineering, University
of California, Berkeley, California 94720, United States
| | - Saul H. Lapidus
- Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States,X-ray
Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - John T. Vaughey
- Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States,Chemical
Sciences and Engineering Division, Argonne
National Laboratory, Lemont, Illinois 60439, United States
| | - Gerbrand Ceder
- Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States,Department
of Materials Science and Engineering, University
of California, Berkeley, California 94720, United States,Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Kenneth R. Poeppelmeier
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States,Joint
Center for Energy Storage Research, Argonne
National Laboratory, Argonne, Illinois 60439, United States,
| |
Collapse
|
2
|
Wang Z, Qu S, Xiang H, He Z, Shen J. Ferromagnetic Half-Metal Cyanamides Cr(NCN) 2 Predicted from First Principles Investigation. MATERIALS 2020; 13:ma13081805. [PMID: 32290419 PMCID: PMC7216073 DOI: 10.3390/ma13081805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 11/16/2022]
Abstract
The stability, physical properties, and electronic structures of Cr(NCN)2 were studied using density functional theory with explicit electronic correlation (GGA+U). The calculated results indicate that Cr(NCN)2 is a ferromagnetic and half-metal, both thermodynamically and elastically stable. A comparative study on the electronic structures of Cr(NCN)2 and CrO2 shows that the Cr atoms in both compounds are in one crystallographically equivalent site, with an ideal 4+ valence state. In CrO2, the Cr atoms at the corner and center sites have different magnetic moments and orbital occupancies, moreover, there is a large difference between the intra- (12.1 meV) and inter-chain (31.2 meV) magnetic couplings, which is significantly weakened by C atoms in Cr(NCN)2.
Collapse
Affiliation(s)
- Zhilue Wang
- School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China; (Z.W.); (S.Q.); (J.S.)
| | - Shoujiang Qu
- School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China; (Z.W.); (S.Q.); (J.S.)
| | - Hongping Xiang
- School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China; (Z.W.); (S.Q.); (J.S.)
- Correspondence: (H.X.); (Z.H.)
| | - Zhangzhen He
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
- Correspondence: (H.X.); (Z.H.)
| | - Jun Shen
- School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China; (Z.W.); (S.Q.); (J.S.)
| |
Collapse
|