Structure and reversible lithium intercalation in a new P′3-phase: Na2/3Mn1−yFeyO2 (y = 0, 1/3, 2/3)

Abstract

International audienceIn this contribution, new data on the reversible Li+ intercalation in iron substituted sodium manganates are provided. Novel Na2/3Mn1−yFeyO2 (y = 0, 1/3 and 2/3) compounds with a P′3-type structure are prepared from freeze-dried citrate precursors at 500 °C. A new structural element is the development of three-layer oxygen stacking contrary to the well-known P2-type Na2/3MnO2 with a two-layer sequence. The effect of Fe additives on the structure of Na2/3MnO2 was examined by XRD powder diffraction and TEM analysis. The oxidation state and the distribution of transition metal ions in Na2/3Mn1−yFeyO2 were analysed using electron paramagnetic resonance spectroscopy. The lithium intercalation in Na2/3Mn1−yFeyO2 was investigated in two-electrode lithium cells of the type Li|LiPF6 (EC:DMC)|Na2/3Mn1−yFeyO2. The stability of the layered phases during lithium intercalation was studied by ex situ Raman spectroscopy. It was found that the intermediate Na2/3Mn2/3Fe1/3O2 composition is able to intercalate Li+ reversibly in high amounts. Details of the structure and its stability during the Li+ intercalation are discussed

P2-Na0.6[Cr0.6Ti0.4]O2 cation-disordered electrode for high-rate symmetric rechargeable sodium-ion batteries

“…In the case of transition metal ordering, we found that as expected it is mainly controlled by the difference in the ionic radii of M1 and M2, as illustrated by a large number of P2-layered oxides689121314151617181920212223242526272829303132333435. Large difference in ionic radii is favourable for forming ordered arrangement while small difference tends to form disordered arrangement.…”

Recent research progress on iron- and manganese-based positive electrode materials for rechargeable sodium batteries

“…Because the P2 and O3 phases have similar particle morphology (figure 5), the kinetic limitation related to the diffusion length is not responsible for the difference in performance. Research interest in the Na–Fe–Mn system as high-capacity electrode material is rapidly increasing, and now the electrode performance for P2- and O3-Na x [Fe y Mn 1 −  y ]O 2 with different chemical compositions has been determined [68–70]. …”

Influence of Mn/Fe Ratio on Electrochemical and Structural Properties of P2-NaxMn1–yFeyO2 Phases as Positive Electrode Material for Na-Ion Batteries

“…[1][2][3][4][5][6][7] Among the various materials studied, sodium layered oxides (NaxMO2, M = transition metal) represent a promising family [8][9][10] . The most promising candidates are based on the Mn and / or Fe elements, which are the less expensive ones among the 3d elements: Nax(Mn,Fe)O2 [11][12][13][14][15][16][17][18][19] , Nax(Mn,Ni)O2 [20][21] , Nax(Mn,Mg)O2 [22][23][24] , Nax(Mn,Ni, Fe)O2 [25][26][27] , Nax(Mn,Co)O2 [28][29][30][31] Nax(Mn,Ni, Co)O2 [32][33][34][35][36][37][38][39] ,Nax(Li,Ni,Mn)O2 [39][40] .…”