New process for the preparation of M²⁺–V₂O₅–H₂O xerogels and their transformation to α-M²⁺–V₂O₅bronzes (M  Ca, Mn, Co, Ni, Cu)

Abstract

Five kinds of M2+-V205-H20 xerogels (M=Ca, Mn, Co, Ni, Cu) have been synthesized by a simple aging of V,05 powder in aqueous solutions of MCI, below 100 "C. These xerogels had a layer structure with a spacing between 1.20 (for Cu) and 1.38 nm (for Co), larger than the V205 xerogel. The x-M2+-V20, bronzes were obtained by thermal dehydration of the corresponding xerogel at temperatures up to 450 "C. The bronzes synthesized had orthorhombic structure, similar to V,05, and each M2+ was located between the a6 planes of V,05. The dehydration behaviour and the structural change from xerogel to bronze were also studied.

Influence of vanadium doping on the electrochemical performance of nickel oxide in supercapacitors

“…For all V-doped NiO samples, a weak and slightly exothermic peak related to vanadium oxide is observed at about 420 1C. 24 Therefore, we choose 500 1C as the calcination temperature to form V 2 O 5 with full oxidation of vanadium species and the decomposition of various organic moieties. The as-prepared samples were analyzed by X-ray diffraction (XRD, D/Max-2500/PC, Rigaku, Japan) using Cu Ka radiation at 40 kV and 200 mA.…”

Soft process for the intercalation of ammonium cations into vanadium oxide

“…In the reaction product from the solution with TMA/V 2 O 5 of 0.1, a weak 001 peak for the xerogel appears at around 6.8 ± in 2u, in addition to the starting crystalline V 2 O 5 with strong and sharp diffraction peaks. 8 In the case of the compound with AN, on the other hand, an additional reaction of oxidation and polymerization of aniline to polyaniline had to be taken into consideration, because V 2 O 5 was an oxidizing agent. AN, all peaks in their XRD patterns are able to be indexed as 00l lines up to 007 and 110 line which shifts toward a little low angle side [ Fig.…”

“…1,2 Because of its characteristic structural and chemical properties, vanadium xerogel was studied as a cathode material for lithium batteries. 6,7 In our previous works, a new soft process to synthesize the vanadium xerogel containing mono-and divalent metal cations was developed 8,9 ; by aging an aqueous solution of chlorides of metal cations (Li 1 , Na 1 , K 1 , Ca 21 , Mn 21 , Co 21 , Ni 21 , and Cu 21 ) with V 2 O 5 powder either at 100 or 60 ± C, vanadium xerogels containing various metal cations in their interlayer spaces were obtained. 5 Intercalation of ammonium cations of alkyl chains with various lengths was carried out, and three different orientation schemes, depending on the length of alkali chain, were found.…”

Carbon-vanadium Nitride Composite for Electrode with High-rate Capability

“…of 0.2 mol dm -3 under refluxing for 24 hours (6,7), molar ratio of NH 4 Cl/V 2 O 5 being 1/1 and polyacrylicacid equivalent to V 2 O 5 weight being also dissolved in the NH 4 Cl aq. before refluxing.…”