Resonant photoemission spectroscopy of the cathode material LixMn0.5Fe0.5PO4 for lithium-ion battery

Large Charge‐Transfer Energy in LiFePO4 Revealed by Full‐Multiplet Calculation for the Fe L3‐edge Soft X‐ray Emission Spectra

“…The surface‐sensitive total‐electron‐yield (TEY) XAS spectra for a – e are shown in Figure . For a at 4.3 V (charged state), the Fe L 2,3 ‐edge XAS spectrum was ascribed to Fe 3+ high‐spin (HS) state as reported in previous results . As discharging, the XAS spectrum gradually changed.…”

“…For aa t4 .3 V( charged state), the Fe L 2,3 -edge XAS spectrum was ascribed to Fe 3 + high-spin (HS) state as reported in previous results. [11][12][13][14] As discharging, the XAS spectrum gradually changed. The L 3 main peak at 710.0 eV became small.…”

An additional discharge plateau of Mn3+ in LiFe0.5Mn0.5PO4 at high current rates

“…Previous reports indicated that mixed-cation olivine material LiFe x Mn (1 − x) PO 4 combined the good rate capability of LiFePO 4 and high potential of LiMnPO 4 [3,4]. For this reason, the series of LiFe x Mn( 1 − x )PO 4 materials, especially LiFe 0.5 Mn 0.5 PO 4, has attracted a great deal of attention [5][6][7][8][9][10][11]. Commonly, LiFe 0.5 Mn 0.5 PO 4 is considered to exhibit two pairs of plateaus in charge/discharge curves associated with MnPO 4 /LiMnPO 4 and FePO 4 /LiFePO 4 phase transformation.…”

Correlation between the O 2p Orbital and Redox Reaction in LiMn0.6Fe0.4PO4 Nanowires Studied by Soft X‐ray Absorption

“…An enhancement of the Mn 3+ multiplet structure was observed in the Mn L ‐edge XAS spectrum of Li x MnPO 4 with extraction of Li, but the Mn 2+ HS state remained considerably at x= 0.25 . Thus, the dominant Mn 2+ HS character observed in Mn L ‐edge XAS spectra at the charged state should be a common feature of LiMn y Fe 1− y PO 4 compounds, although the 4.0 V plateau was observed for all these studies . In addition, if the 4.0 V plateau corresponded to the redox couple of Mn 2+ /Mn 3+ within the discharge curve having the total capacity of 98 mA h g −1 , as small as approximately 60 % of the theoretical capacity, not only the Mn L ‐edge XAS, but also the Fe L ‐edge XAS at 4.3 V should have exhibited both divalent and trivalent multiplet structures.…”

“…Kurosumi et al. have performed Mn and Fe L ‐edge XAS for Li x Mn 0.5 Fe 0.5 PO 4 . They reported a capacity of 160 mA h g −1 (0< x <1.0), suggesting that the Fe and Mn were completely reduced/oxidized as Fe 3+ /Fe 2+ and Mn 3+ /Mn 2+ in the discharge–charge process.…”