Effect of transition metal cations on the local structure and lithium transport in disordered rock-salt oxides

Abstract

Lithium-excess oxides Li1.2Ti0.4Mn0.4O2 and Li1.3Nb0.3Mn0.4O2 with a disordered rock-salt structure and Mn3+/Mn4+ as a redox couple were compared to analyze the effect of different d0 metal ions on the local structure and Li+ ion migration.

Effect of cooling rate on the structure and electrochemical properties of Mn-based oxyfluorides with cation-disordered rock-salt structure

“…Previously, the formation of ONb6 and OMn1Nb5 octahedra, more stable than Mn-rich ones, was confirmed in DRX oxide Li1.3Nb0.3Mn0.4O2 by computational methods [8]. On the other hand, using geometricaltopological method (bond-valence site energy modeling, BVSE), and density functional theory (DFT) calculations, we demonstrated that Mn ions form MnO6 clusters, which are preferably linked in dense layers in Li1.3Nb0.3Mn0.4O2, and negatively affects lithium diffusion [9]. The formation of Mn clusters was also confirmed by EPR and NMR spectroscopy [9][10][11].…”

“…Earlier, it was found that the Li1.3Nb0.3Mn0.4O2 oxide has a tendency to form the Mn 3+ -O-Mn 4+ clusters [9]. On the other hand, the authors [10] revealed ferromagnetic interactions in Li1.2Ti0.4Mn0.4O2 oxide during cycling.…”

Expandable Li Percolation Network: The Effects of Site Distortion in Cation-Disordered Rock-Salt Cathode Material

“…For example, the current finding of Li–Ti and Ni–Ni clustering preference in LTNNO is in line with the previous theoretical investigations, where prominent Li–Ti and Ni–Ni clusterings were found in a DRX material Li 1.0 Ti 0.5 Ni 0.5 O 2 . Regarding the Nb 5+ cations, Semykina et al pointed out that, in a Li 1.3 Nb 0.3 Mn 0.4 O 2 system, the presence of Nb 5+ tends to prompt the segregation of Mn 3+ cations …”

“…As shown in Figure 2d, the composition of TM elements shows a monotone change as the TM number in the cation cluster , the presence of Nb 5+ tends to prompt the segregation of Mn 3+ cations. 52 In the view of thermodynamics, the formation of SRO in DRX material is driven by the preferred phase segregation at the low temperature, thus resembling the structural features of its ground state. The existence of such structurally ordered domains strongly affects Li + mobility within DRX material.…”

Lithium-rich sulfide Li2Ti1−xSixS3 cathode materials optimized through Si-doping for high-capacity all-solid-state lithium-ion batteries

“…[8][9][10][11][12] Several transition metals such as Mn, Ti, V, and Cr have been utilized to synthesize DRXs with capacities of up to 300 mA h g −1 . [13][14][15][16][17] Transition metal cation mixing, 11,18 shortrange ordered structure analysis, [19][20][21][22] and the Li + migration mechanism [23][24][25][26] are highly researched to activate the high capacity and improve the rate performance of DRXs. Recently, Konuma et al reported a "near dimensionally invariable" material Li 8/7 Ti 2/7 V 4/7 O 2 , which was encapsulated in Li 6 PS 5 Clbased ASSBs using a PEEK mold and achieved a capacity of 300 mA h g −1 at a high operating pressure of 200 MPa and a current of 0.2 C (60 mA g −1 ).…”