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Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
(NaFeO2)2(NaFe3O4)3 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one NaFeO2 ribbon oriented in the (-1, 1, 1) direction and one NaFe3O4 sheet oriented in the (0, 1, -1) direction. In the NaFeO2 ribbon, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.87 Å) and one longer (1.92 Å) Na–O bond length. In the second Na1+ site, Na1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.82 Å) and one longer (1.86 Å) Na–O bond length. There are two inequivalent Fe+2.45+ sites. In the first Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.64 Å) and one longer (1.70 Å) Fe–O bond length. In the second Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.66 Å) and one longer (1.69 Å) Fe–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the NaFe3O4 sheet, there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.85 Å) and one longer (1.89 Å) Na–O bond length. In the second Na1+ site, Na1+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.85 Å) and one longer (1.89 Å) Na–O bond length. In the third Na1+ site, Na1+ is bonded in a distorted linear geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 1.86–2.61 Å. There are nine inequivalent Fe+2.45+ sites. In the first Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Fe–O bond distances ranging from 1.60–2.11 Å. In the second Fe+2.45+ site, Fe+2.45+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Fe–O bond distances ranging from 1.72–2.46 Å. In the third Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to three O2- atoms. There are two shorter (1.66 Å) and one longer (2.56 Å) Fe–O bond lengths. In the fourth Fe+2.45+ site, Fe+2.45+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.70 Å) and one longer (1.76 Å) Fe–O bond length. In the fifth Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.80 Å) and one longer (1.81 Å) Fe–O bond length. In the sixth Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.79 Å) and one longer (1.82 Å) Fe–O bond length. In the seventh Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.69 Å) and one longer (1.77 Å) Fe–O bond length. In the eighth Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.73 Å) and one longer (1.87 Å) Fe–O bond length. In the ninth Fe+2.45+ site, Fe+2.45+ is bonded in a 2-coordinate geometry to two O2- atoms. Both Fe–O bond lengths are 1.67 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Fe+2.45+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Fe+2.45+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Fe+2.45+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to one Na1+ and four Fe+2.45+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two Fe+2.45+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Fe+2.45+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two Fe+2.45+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two Fe+2.45+ atoms. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and one Fe+2.45+ atom.
The demand for developing high-energy density cathode materials has been increasing. The energy densities of cathode materials have been improved by adapting structural deviation from the ideal fully ordered α-NaFeO2 type, but that led to limitations in terms of structural stability and safety. Although disorders in cathode materials are closely related to their electrochemical properties, unfortunately, characterizing the disorder itself in cathode materials has been challenging due to its complex parasitic reaction and strong correlation with other disorders occurring during charge/discharge. In this review, we categorize various disorders by their scales of ordering from short-range to long-range. We addressed the principles of various characterization tools to figure out how they can help to identify the structural disorder in cathode materials. Specifically, we focused on the underlying principles of each characterization technique to correlate different disorder-driven phenomena through several case studies. It underscores the substantial importance of disorder-property relationships and the corresponding characterization methods, which can provide novel research strategies for developing high-energy density cathode materials with decent structural stability.