Predominant growth orientation of Li_1.2(Mn_0.4Co_0.4)O₂cathode materials produced by the NaOH compound molten salt method and their enhanced electrochemical performance

Self-transforming ultrathin α-Co(OH)2 nanosheet arrays from metal-organic framework modified graphene oxide with sandwichlike structure for efficient electrocatalytic oxygen evolution

“…These EELS spectra clearly show L3 and L2 edges of cobalt at 779.2 and 794.3 eV and the intensity ratio of the L3 to L2 peaks keeps around at 4.3, implying that the structure of Co(OH)2-GNS-x samples remains unchanged and chemical valence of cobalt in all compound is about +2 [34,35], which is supported by XRD and XPS analysis. High-resolution XPS spectrum of Co 2p of Co(OH)2-GNS-3 (Fig.…”

Flux-mediated crystal growth of metal oxides: synthetic tunability of particle morphologies, sizes, and surface features for photocatalysis research

“…In the case of a PbO flux with a TiO 2 precursor, the flux liberates O 2− anions in which can then react with Pb 2+ cations in solution to form PbTiO 3 . [3][4][5]7,13,22,31,[54][55][56][57][58][59][60][61][62] Molten fluxes that tend to form strongly oxidizing species or complex metallates in solution act to stabilize structures with higher oxidation states. Molten-salt fluxes can also be used in binary combinations to form eutectic mixtures that are advantageous owing to their reduced melting points and lower viscosity, e.g., NaCl-KCl and Na 2 SO 4 -K 2 SO 4 .…”

“…These guidelines have been the driving force for the growth of mixed-metal oxide nanocrystals, such as Cu 2 Nb 8 O 21 , 15 ATiO 3 (A = Sr, Ba, Pb), 13,[78][79][80][81][82] ANbO 3 (A = Li, Na, K), [83][84][85] LaMnO 3 , 78 BaTi 2 O 5 , 86 Sr 2 SbMnO 6 , 87 and for several Li-ion battery materials. 59,[88][89][90][91] In all cases, the initial size and morphology of the less soluble metal-oxide precursors (e.g., TiO 2 , Nb 2 O 5 ) have largely determined the morphology and nanoscale dimensions of the desired This journal is © The Royal Society of Chemistry 2015 products, such as nanoparticulate rods, spheres, cubes, platelets, and wires. Synthetic modulation of the particle characteristics can also have a large impact on metal-oxide surfaces that influence their photocatalytic properties, as described below.…”

“…Phases containing transition-metal cations with higher oxidation states (e.g., LaFeO 3 ) can be stabilized by superoxides and peroxides that form in alkali-metal hydroxide fluxes at lower reaction temperatures, e.g., NaOH-KOH eutectic. 4,5,7,22,31,54,56,57,59,60,90,[124][125][126] The crystalline rareearth orthoferrites LnFeO 3 (Ln = La, Pr, Nd) have been synthesized by flux methods at a temperature of 400 °C using a molten hydroxide in a 10 : 1 flux-to-reactant molar ratio. 22 The syntheses of the LnFeO 3 phases were attempted by means of a eutectic NaOH-KOH flux with a heating temperature of 300-500 °C and a reaction time of 6-24 h. The hydroxide eutectic flux has a reduced melting point and increased oxobasicity from incorporating KOH.…”

Li‐Rich Li[Li1/6Fe1/6Ni1/6Mn1/2]O2 (LFNMO) Cathodes: Atomic Scale Insight on the Mechanisms of Cycling Decay and of the Improvement due to Cobalt Phosphate Surface Modification

“…), also termed x Li 2 MnO 3 ·(1 − x )LiMO 2 (0 < x < 1), are attracting significant attention due to the high voltage and capacity, enhanced thermal stability, and lower cost . These Li‐rich cathode materials may be considered as two interpenetrating lattices of the monoclinic C 2 /m Li 2 MnO 3 structure and the trigonal R‐ 3 m LiMO 2 structure . The Li 2 MnO 3 is irreversibly activated to Li x MnO y at potentials higher than 4.5 V versus Li/Li + .…”