| PXRD, milled sample | Poor crystallinity made Rietveld analysis infeasible; the approximate 1:2 ratio of the peaks at 14° and 29° 2θ indicated formation of the Fd3̅m structure |
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| PXRD, annealed samples | Annealing at 300 °C retained the Fd3̅m structure; after 6 months at room temperature, 27 % of the Fd3̅m phase had converted to Cmmm, increasing to 32 % after 9 months; the product annealed at 400 °C contained 14 % Cmmm and 86 % Fd3̅m |
| EIS at 25 °C | Ionic conductivity was 0.023 mS cm⁻¹ for Fd3̅m Li₂FeCl₄ and decreased to 0.0038 and 0.0014 mS cm⁻¹ in samples containing 27 and 32 % Cmmm, respectively |
Jon A. Newnham, Jaeyoung Cho, John W. Still, Graeme Henkelman, Ieuan D. Seymour. “Induced structural disorder enables high ionic conductivity and capacity in Li₂Fe₁−ₓMnₓCl₄ cathodes.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15005178/v2
Values presented only in powder X-ray diffraction, SEM-EDX, DC-polarization or electrochemical-impedance-spectroscopy plots or images were not transcribed. The main paper refers to supporting information, but no separate supporting information file was available on the ChemRxiv article page
| PXRD | All compositions, synthesized in steps of x = 0.25, formed the Fd3̅m polymorph and contained approximately 4 wt % LiCl; the refined lattice parameter increased linearly with x, and both the metal octahedra and Li⁺ tetrahedra increased in volume with increasing Mn²⁺ content; none of the Mn²⁺-containing samples converted to Cmmm or Imma after 6 months |
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| SEM-EDX | Measured Fe:Mn ratios from multiple particles closely matched the nominal compositions |
| EIS, 25–60 °C | A single semicircle was observed for every sample at every temperature; at 25 °C, ionic conductivity decreased from 0.023 mS cm⁻¹ for Li₂FeCl₄ to 0.0012 mS cm⁻¹ for Li₂MnCl₄; activation energy increased from 0.46 to 0.57 eV across the same end members |
| DC polarization at 25 °C | Electronic conductivities were approximately 10⁻¹⁰ S cm⁻¹, about five orders of magnitude below the ionic conductivities, with no distinct compositional trend |
| SEM-EDX | Cl content was the same before and after cycling |
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| PXRD | No difference was found before and after cycling, although the carbon content and mixing step made the patterns difficult to interpret fully |