Influence of the Lattice Parameter Difference between the Two Cubic Phases Formed in the 4 V Region on the Capacity Fading of Spinel Manganese Oxides

Abstract

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Three‐Dimensional Microstructural Characterization of Lithium Manganese Oxide with Atom Probe Tomography

“…All peaks could be assigned to an element or molecule.P eaks for the atomic species Li, Mn, and Od ominate the spectrum,a nd different isotopes,f or example,f rom Li, can be distinguished. Theo bserved ratio between the Li isotopes 7 Li and 6 Li after subtractingt he exponentially decaying noise level is 7 Li/ 6 Li = 12.06, which is in good agreement with the theoretical value of 12.16 for an atural isotope mixture. Additionally,peaks for molecules of Mn andOwith different charge states are found, as typically observed for oxides.…”

“…All three materials were expected to have ac ubic crystal structure with the space group Fd3 m. Thel attice parameter for material Aw as reported between 0.824 and 0.825 nm. [2][3][4][5][6][7]41] Form aterial B, it was expected to differ slightly owing to doping, and for material Cal attice parameter of 0.8185(3) nm was reported. [37] Samplepreparation Samples for atom probe tomography were prepared as nanoscopic needles by using two different focused ion beam (FIB)-based techniques,s chematically shown in Figure 12.…”

“…Examples are X-ray diffractions tudies on structural changes in lithium manganese oxide (LMO)i nduced by Li (de)intercalation [1][2][3][4][5][6] and on the influence of dopants in LMO on the cycling performance [7] in addition to electrochemical impedances pectroscopy studies on the Li-insertion process in Li x Mn 2 O 4 to develop an atomic modelf or Li insertion. [8,9] Am ore detailed understanding of the processes determining battery performance requires the investigation of the individual battery components and their interaction.…”

Microwave-assisted optimization of the manganese redox states for enhanced capacity and capacity retention of LiAlxMn2−xO4 (x = 0 and 0.3) spinel materials

“…High content of Mn 3+ ions causes capacity fading, and leads to the dissolution of the cathode material into the electrolyte. There are three known strategies for improving the cycling performance of LMO; (i) making the spinel structure lithium-rich (Li-excess), [16][17][18] (ii) doping with cations [19][20][21] and (iii) coating with metal oxides. Aluminium is a preferred dopant for LMO [16][17][18] since it is abundant, non-toxic, less expensive and lighter than transition metal elements.…”

Sucrose-aided combustion synthesis of nanosized LiMn1.99−yLiyM0.01O4 (M=Al3+, Ni2+, Cr3+, Co3+, y=0.01 and 0.06) spinels

“…(R.M. Rojas).the discharge on the surface of the particles [8]; (iii) mechanical instability generated by structural changes occurring during Li + -de/insertion in the charge/discharge steps [9,10]. It is possible that the three phenomena contribute simultaneously to the capacity fade of the LiMn 2 O 4 electrode.…”