Methods of stabilizing a vanadium compound in a solution, compositions including a vanadium compound and a stabilizing agent, apparatus including the composition, systems that use the composition, and methods of using the compositions, apparatus, and systems are disclosed. Use of the stabilizing agent allows for use of desired precursors, while mitigating unwanted decomposition of the precursors.

Methods of stabilizing a vanadium compound in a solution, compositions including a vanadium compound and a stabilizing agent, apparatus including the composition, systems that use the composition, and methods of using the compositions, apparatus, and systems are disclosed. Use of the stabilizing agent allows for use of desired precursors, while mitigating unwanted decomposition of the precursors.

Methods of stabilizing a vanadium compound in a solution, compositions including a vanadium compound and a stabilizing agent, apparatus including the composition, systems that use the composition, and methods of using the compositions, apparatus, and systems are disclosed. Use of the stabilizing agent allows for use of desired precursors, while mitigating unwanted decomposition of the precursors.

Provided are sodium battery positive electrode materials and preparation methods therefor, positive electrode sheets and sodium batteries. The positive electrode materials may comprise a core and a coating layer coating the surface of the core, where the general molecular formula of the core comprises Na.sub.3V.sub.2-xM.sub.x(PO.sub.4).sub.2F.sub.3, wherein M represents a doping element capable of replacing V, element M comprises at least one of Fe, Cr, Mn, Co, Ti, Ni, Cu, Zn, Mo, Nb, Zr, La and Ce, and 0x<0.2. The material for the coating layer comprises a carbon material, wherein the I.sub.D/I.sub.G value of a Raman spectrum of the carbon material is y, and 0.9y<1. I.sub.D/I.sub.G is the peak intensity ratio of peak D to peak G of the Raman spectrum of the carbon material, a Raman shift of peak D ranges from 1300 cm.sup.1 to 1360 cm.sup.1, and a Raman shift of peak G ranges from 1580 cm.sup.1 to 1600 cm.sup.1.

Provided are sodium battery positive electrode materials and preparation methods therefor, positive electrode sheets and sodium batteries. The positive electrode materials may comprise a core and a coating layer coating the surface of the core, where the general molecular formula of the core comprises Na.sub.3V.sub.2-xM.sub.x(PO.sub.4).sub.2F.sub.3, wherein M represents a doping element capable of replacing V, element M comprises at least one of Fe, Cr, Mn, Co, Ti, Ni, Cu, Zn, Mo, Nb, Zr, La and Ce, and 0x<0.2. The material for the coating layer comprises a carbon material, wherein the I.sub.D/I.sub.G value of a Raman spectrum of the carbon material is y, and 0.9y<1. I.sub.D/I.sub.G is the peak intensity ratio of peak D to peak G of the Raman spectrum of the carbon material, a Raman shift of peak D ranges from 1300 cm.sup.1 to 1360 cm.sup.1, and a Raman shift of peak G ranges from 1580 cm.sup.1 to 1600 cm.sup.1.

This disclosure relates to a process for selective extraction and separating vanadium and iron using a method of chlorinating vanadium-containing iron oxide ores. More particularly, the disclosure relates to a process for producing vanadium oxytrichloride (VOCl.sub.3) and iron trichloride (FeCl.sub.3) in a moving bed chlorinator by reacting chlorine and carbon monoxide with vanadium iron oxide materials. In addition, this disclosure describes removing other chlorides with the exemption of vanadium and iron chlorides from the exhaust stream from the reactor by creating a conversion temperature zone at the top of the reactor. Furthermore, the invention discloses removing impurities from an exhaust gas stream to purify carbon dioxide and it also includes a closed-loop capture in the process in order to convert carbon dioxide to carbon monoxide.