ChemInform Abstract: Nickel‐Molybdenum Sulfide Ni2Mo6S7.9 as the Cathode of Lithium Secondary Batteries.

Abstract

ChemInform Abstract The galvanostatic discharge curve of the Li/Ni2Mo6S7.9 cell indicates that up to 4-5 Li atoms per formula unit can be intercalated into this nickel Chevrel phase (LixNi2Mo6S7.9, x = 4-5) when the current density is < 0.5 mA/cm2. Upon Li intercalation nly small expansion of the crystal lattice occurs and distortion of the crystal lattice is negligible. No evidence of Ni deposition from the cathode is observed even when the cell is deeply discharged to x 4. The Ni2Mo6S7.9 cathode exhibits excellent discharge-charge cycling erformance. More than 50% of the initial discharge capacity is retained even after 200 deep cycles between 1.5-2.7 V. In shallow range cycling tests performed in the ranges 0.5 < x < 1 and 1 < x < 2, the cells are cycled more than 5000 and 1700 times, respectively.

A review on the problems of the solid state ions diffusion in cathodes for rechargeable Mg batteries

“…6 Arrangement of cation sites in MgMo 6 T 8 : (a) Two adjacent groups of cation sites (12+12) in the crystal structure of the sulfide, MgMo 6 S 8 , marked by ellipse in the insert. The insert presents the three-dimensional framework of cation sites [35]. (b) Two adjacent groups of cation sites in the crystal structure of the selenide, MgMo 6 Se 8 Mg 2 Mo 6 S 8 .…”

Determination of lithium diffusion coefficient in LiFePO4 electrode by galvanostatic and potentiostatic intermittent titration techniques

“…A mosaic model was shown to be an alternative to the radial model [4]. In most of the works dealing with lithium transport processes in the intercalated electrode material, it is considered as a solid solution with continuous concentration distribution along the diffusion thickness (see, for example, [14][15][16][17]). However, many compounds undergo phase transition during lithium intercalation (see, for example, [18][19][20]).…”

Mixed Metal Sulfides for Electrochemical Energy Storage and Conversion

“…The solid-state method is used earliest to synthesize MMSs, in which two metals and sulfur are first mixed together and then heated at high temperature under inert atmosphere or vacuum condition. [42][43][44][45][46][47] For the solid-state method, it usually needs high temperature (>500 °C) and long reaction time (usually several days). In addition, the solid-state strategy offers little control over the desirable size, morphology, and structure of obtained MMSs.…”

“…[42][43][44][45][46][47] Reproduced with permission. [255] Copyright 2015, American Chemical Society.…”

“…On the other hand, no metal deposition in the cathodes of Ni x Mo 6 S 8−y , Co x Mo 6 S 8−y , Fe x Mo 6 S 8−y , and Cr x Mo 6 S 8−y even after deep cycling resulted in improved cycling behavior. [43][44][45]47] However, their relatively low specific capacities (below 100 mA h g −1 ) and operating voltages (around 2 V vs Li/Li + ) have hindered their use as cathode materials in commercial cells. Conventional pathways for the synthesis of Chevrel phase materials require high temperature (≥1000 °C) and long time (usually several days).…”