A method for selectively removing sodium or potassium from an alkaline lithium-containing aqueous solution, the method comprising: (i) contacting the alkaline lithium-containing aqueous solution with a hydrophobic solution comprising: (a) an aqueous-insoluble hydrophobic solvent, (b) a protic ionic liquid of the formula X.sup.Y.sup.+, wherein X.sup. is a conjugate base of a superacid and Y.sup.+ is a protonated cation, and (c) at least one of lipophilic sodium-selective and potassium-selective complexing ligands, wherein the contacting step results in selective complexation with and removal of sodium and/or potassium ions from the lithium-containing aqueous solution into the hydrophobic solution along with simultaneous abstraction of a proton from Y.sup.+ to form Y; and (ii) separating the aqueous solution from the hydrophobic solution, wherein, in some embodiments, X.sup. is a bis(sulfonyl)imide and Y.sup.+ is a protic ammonium species. The method may further include stripping sodium and potassium ions from the hydrophobic solution and regenerating Y.sup.+.

A method for selectively removing sodium or potassium from an alkaline lithium-containing aqueous solution, the method comprising: (i) contacting the alkaline lithium-containing aqueous solution with a hydrophobic solution comprising: (a) an aqueous-insoluble hydrophobic solvent, (b) a protic ionic liquid of the formula X.sup.Y.sup.+, wherein X.sup. is a conjugate base of a superacid and Y.sup.+ is a protonated cation, and (c) at least one of lipophilic sodium-selective and potassium-selective complexing ligands, wherein the contacting step results in selective complexation with and removal of sodium and/or potassium ions from the lithium-containing aqueous solution into the hydrophobic solution along with simultaneous abstraction of a proton from Y.sup.+ to form Y; and (ii) separating the aqueous solution from the hydrophobic solution, wherein, in some embodiments, X.sup. is a bis(sulfonyl)imide and Y.sup.+ is a protic ammonium species. The method may further include stripping sodium and potassium ions from the hydrophobic solution and regenerating Y.sup.+.

Disclosed is a purification method for removing a metal component from a fluorine compound gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. It is preferable for the fluorine compound gas to contain at least one kind selected from the group consisting of CIF, CIF.sub.3, IF.sub.5, IF.sub.7, BrF.sub.3, BrF.sub.5, NF.sub.3, WF.sub.6, SiF.sub.4, CF.sub.4, SF.sub.6 and BF.sub.3. It is also preferable for the metal fluoride to be an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine compound gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.

Disclosed is a purification method for removing a metal component from a fluorine compound gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. It is preferable for the fluorine compound gas to contain at least one kind selected from the group consisting of CIF, CIF.sub.3, IF.sub.5, IF.sub.7, BrF.sub.3, BrF.sub.5, NF.sub.3, WF.sub.6, SiF.sub.4, CF.sub.4, SF.sub.6 and BF.sub.3. It is also preferable for the metal fluoride to be an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine compound gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.

A positive electrode active material includes a core and a coating disposed on at least a portion of a surface of the core. The core includes a lithium metal oxide, a lithium metal phosphate, or a combination thereof. The coating includes a compound according to the formula Li.sub.mM.sup.1.sub.nX.sub.p, wherein M.sup.1, X, m, n and p are as defined herein. Also, an electrochemical cell including the positive electrode active material, and methods for the manufacture of the positive electrode active material and the electrochemical cell.

A positive electrode active material includes a core and a coating disposed on at least a portion of a surface of the core. The core includes a lithium metal oxide, a lithium metal phosphate, or a combination thereof. The coating includes a compound according to the formula Li.sub.mM.sup.1.sub.nX.sub.p, wherein M.sup.1, X, m, n and p are as defined herein. Also, an electrochemical cell including the positive electrode active material, and methods for the manufacture of the positive electrode active material and the electrochemical cell.

Solid-state lithium ion electrolytes of lithium potassium element oxide based compounds are provided which contain an anionic framework capable of conducting lithium ions. The element atoms are Ir, Sb, I Nb and W. An activation energy of the lithium potassium element oxide compounds is from 0.15 to 0.50 eV and conductivities are from 10.sup.3 to 22 mS/cm at 300K. Compounds of specific formulae are provided and methods to alter the materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided. Electrodes containing the lithium potassium element oxide based materials and batteries with such electrodes are also provided.

Solid-state lithium ion electrolytes of lithium potassium element oxide based compounds are provided which contain an anionic framework capable of conducting lithium ions. The element atoms are Ir, Sb, I Nb and W. An activation energy of the lithium potassium element oxide compounds is from 0.15 to 0.50 eV and conductivities are from 10.sup.3 to 22 mS/cm at 300K. Compounds of specific formulae are provided and methods to alter the materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided. Electrodes containing the lithium potassium element oxide based materials and batteries with such electrodes are also provided.

An aqueous or organic solvent medium for additive manufacturing technologies comprising a nanocrystal comprising a functional group. The nanocrystal material is selected from a metal oxide, fluoride, metallic, carbon-based, semiconducting quantum dot or combinations thereof. The functional group comprises primary amine, carboxylic acid, lactam ring, polyamide polymer chain or group used to attach a similar functional group.

An aqueous or organic solvent medium for additive manufacturing technologies comprising a nanocrystal comprising a functional group. The nanocrystal material is selected from a metal oxide, fluoride, metallic, carbon-based, semiconducting quantum dot or combinations thereof. The functional group comprises primary amine, carboxylic acid, lactam ring, polyamide polymer chain or group used to attach a similar functional group.