Fig 1

Rietveld fit of the (a) X-ray diffraction pattern of LaSr2Mn2O6.96. The Miller indices of main reflections belonging to the active material are marked. (b) Cathode composite of LaSr2Mn2O6.96 containing additional reflections of the electrolyte La0.9Ba0.1F2.9."

Fig 2

SEM micrograph of LaSr2Mn2O6.96 (a) at 1400× magnification (b) 2000x magnification (c) Elemental mapping of the individual elements."

Fig 3

(a) Charging curve of LaSr2Mn2O6.96 Ⅱ La0.9Ba0.1F2.9 Ⅱ Pb-PbF2 cell, the colored arrows mark the selected cutoff potentials at which ex situ XRD measurements were performed. (b) Ex situ diffraction pattern obtained from the individual cells charged at different cut off potentials (Red curve is the annotation of the calculated pristine LaSr2Mn2O6.96 and black vertical dotted line represent how the main peaks are shifted during fluorination)."

Fig 4

(a) Relative weight fractions (RWFs), (b) Lattice parameters a/b, (c) Lattice parameter c, (d) volume changes of different phases formed on charging up to various cut-off capacities."

Fig 5

Schematic of structural changes in LaSr2Mn2O6.96. The schematic illustrates the non-fluorinated LaSr2Mn2O6.96 (left) and the fluorinated phase of LaSr2Mn2O6.96 (right)"

Fig 6

(a) Discharge curve of LaSr2Mn2O6.96 Ⅱ La0.9Ba0.1F2.9 Ⅱ Pb-PbF2 cell, first charged up to 1.5 V and then discharged up to various cut-off capacity. The colored arrows mark the chosen cut off capacities for the discharging process where the ex-situ XRD measurements were taken, (b) Ex situ diffraction pattern obtained from the individual cells charged and discharged at different cut-off capacities (red curve is the annotation of the pristine LaSr2Mn2O6.96 before charging and pristine LaSr2Mn2O6.96 after charging at 150 mAh g−1)."

Fig 7

(a) Relative weight fractions (RWFs), (b) Lattice parameters a/b, (c) Lattice parameter c, (d) volume changes of different phases formed on discharging up to various cut-off capacities."

Fig 8

XANES of LaSr2Mn2O6.96 (a) at different charging states (c) at different discharging states and Fourier-transformed EXAFS spectra (b) at different charging state (d) at different discharging states."

Fig 9

Magnetic Susceptibility versus temperature in an applied field of 0.1 T measured in zero-field cooled and field cooled manner for: (a) the pristine LaSr2Mn2O6.96 polycrystalline sample and the Cathode composite. (b) the cathode composite with increasing charging of 0, 20, 80 and 350 mAh g−1. (c) the cathode composite charged up to 150 mAh g−1 and then with increasing discharging of 0, 10, 100 and 120 mAh g−1."

Fig 10

Cycling curves of LaSr2Mn2O6.96/Pb-PbF2 at T = 170 ℃, Icharge = +10 μA, Idischarge = −10 μA, at the potential (a) 1.5 V to −1.5 V without pressure and (c) 1.5 V to −1.5 V with pressure of 20 kN, charge/discharge capacities and coulombic efficiency against cycle number for the cells with the cut-off potential (b) 1.5 V to −1.5 V without pressure and (d) 1.5 V to −1.5 V with pressure of 20 kN. (The potential limitations were chosen taking into account the structural changes of the active material derived in Fig. 3)."

Fig 11

Cycling curves of LaSr2Mn2O6.96/Pb-PbF2 at T = 170 ℃, Icharge = +10 μA, Idischarge = −10 μA, at the potential (a) 1.0 V to −1.0 V without pressure and (c) 1.0 V to −1.0 V with pressure of 20 kN, charge/discharge capacities and coulombic efficiency against cycle number for the cells with the cut-off potential (b) 1.0 V to −1.0 V without pressure and (d) 1.0 V to −1.0 V with pressure of 20 kN. The increased noise in cycling curves shown in c) likely originate from the fact that the pressured cell is cycled in the glovebox, i.e., the ventilation can result in a bit stronger thermal fluctuations and cable connections are also different."