Ultrathin Nanosheets of Li₂MSiO₄ (M = Fe, Mn) as High-Capacity Li-Ion Battery Electrode

Abstract

Novel ultrathin Li(2)MnSiO(4) nanosheets have been prepared in a rapid one pot supercritical fluid synthesis method. Nanosheets structured cathode material exhibits a discharge capacity of ~340 mAh/g at 45 ± 5 °C. This result shows two lithium extraction/insertion performances with good cycle ability without any structural instability up to 20 cycles. The two-dimensional nanosheets structure enables us to overcome structural instability problem in the lithium metal silicate based cathode materials and allows successful insertion/extraction of two complete lithium ions.

Tuning anisotropic ion transport in mesocrystalline lithium orthosilicate nanostructures with preferentially exposed facets

“…The subsequent charge curve is fairly different from the primary charge curve (Fig. 5a), with the peak at 4.65 V disappearing and the peak at 3.26 V shifting to 3.05 V. This phenomenon (~0.3 V voltage drop) is ascribed to structural rearrangements involving Li and Fe atom position exchange during the first charge 18,44,49,63 . After Li/Fe cation exchange and structural rearrangement during the initial charge process, the Pmn2 1 orthorhombic structure changes to an inverse-β II orthorhombic structure as Li cations reinsert into the structure during the subsequent discharge process, in which Li ions diffuse mainly along the [010] and [001] directions 47,50,51,64 .…”

“…The high percentage of C-C sp 2 (66.1%) indicates that the carbon nanolayers are composed mostly of graphite, which is consistent with the Raman results. In addition, the Fe 2p 3/2 peak at the BE of 711.75 eV ( Figure S5d) and the Fe 3p peak at the BE of 55.15 eV ( Figure S5c) 49 .…”

“…5b) 50,51 . Theoretically, half of the capacity (~165 mAhg −1 ) should be observed at the first charge plateau of~3.1V, corresponding to the oxidation of Fe 2+ to Fe 3+ , and another half capacity should be observed for the second charge plateau of~4.6V (Fe 3+ to Fe 4+ ) 13,47,[49][50][51][52][53] . However, the initial charge capacity at the 3.1 V plateau is less than 165 mA hg -1 (~70 mA hg −1 in this work), which has also been observed in previous work 17,18,20,21,24,27,47,50,51,[53][54][55][56][57][58][59][60][61] .…”

Hydrothermal Synthesis and Electrochemical Properties of Li₂Fe<i>_x</i>Mn<i>_x</i>Co_1&minus;2<i>_x</i>SiO₄/C Cathode Materials for Lithium-ion Batteries

“…4 5,9,10 its practical discharge capacity is less than 166 mAh g ¹1 (half of the theoretical value) between 4.5 and 1.5 V (electrolyte stability window). 11 On the other hand, Li 2 FeSiO 4 delivers a discharge capacity greater than 300 mAh g ¹1 between 4.8 and 1.5 V. 12 Li 2 MnSiO 4 , with a theoretical discharge capacity of 333 mAh g…”

Mechanically robust Si nanorod arrays on Cu/Ti bilayer film coated Si substrate for high performance lithium-ion battery anodes

“…8 In the past decade, a great deal of effort has already been invested in developing different morphological nanostructures, such as nanosheets, nanowires, nanotubes, and nanoparticles, to minimize electrode pulverization and capacity loss. [22][23][24] However, to the best of our knowledge, mechanical characterization of such nanostructured anode materials is still absent in the literature.…”