Na ₃ MnZr(PO ₄ ) ₃ : A High-Voltage Cathode for Sodium Batteries

Journal Article · Sun Dec 02 00:00:00 EST 2018 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/jacs.8b11388· OSTI ID:1543730

Gao, Hongcai  ^[1]; Seymour, Ieuan D. ^[2]; Xin, Sen  ^[1]; Xue, Leigang  ^[1]; Henkelman, Graeme  ^[2]; Goodenough, John B.  ^[1]

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1. Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
2. Department of Chemistry and the Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, United States

Sodium batteries have been regarded as promising candidates for large-scale energy storage application, provided cathode hosts with high energy density and long cycle life can be found. Herein, we report NASICON-structured Na₃MnZr(PO₄)₃ as a cathode for sodium batteries that exhibits an electrochemical performance superior to those of other manganese phosphate cathodes reported in the literature. Both the Mn⁴⁺/Mn³⁺ and Mn³⁺/Mn²⁺ redox couples are reversibly accessed in Na₃MnZr(PO₄)₃, providing high discharge voltage plateaus at 4.0 and 3.5 V, respectively. A high discharge capacity of 105 mAh g^–1 was obtained from Na₃MnZr(PO₄)₃ with a small variation of lattice parameters and a small volume change on extraction of two Na⁺ ions per formula unit. Moreover, Na₃MnZr(PO₄)₃ exhibits an excellent cycling stability, retaining 91% of the initial capacity after 500 charge/discharge cycles at 0.5 C rate. On the basis of structural analysis and density functional theory calculations, we have proposed a detailed desodiation pathway from Na₃MnZr(PO₄)₃ where Mn and Zr are disordered within the structure. We further show that the cooperative Jahn–Teller distortion of Mn³⁺ is suppressed in the cathode and that Na₂MnZr(PO₄)₃ is a stable phase

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of Texas, Austin, TX (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: SC0005397
• OSTI ID: 1543730
• Journal Information: Journal of the American Chemical Society, Vol. 140, Issue 51; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

Chemistry