A renewable magnesium removing agent and its use in a preparation of a low-magnesium lithium-rich brine are provided. The magnesium removing agent includes a magnesium phosphate double salt of an alkali metal or ammonium. A regeneration of the magnesium removing agent is realized by adding the magnesium removing agent into Mg.sup.2+-containing chloride salt solution, wherein Mg.sup.2+ in the chloride salt solution and the magnesium removing agent are subjected to a magnesium removing reaction to form a solid-phase reaction product and carrying out a solid-liquid separation on an obtained mixed reaction product after the magnesium removing reaction is ended to separate the solid-phase material comprising a magnesium phosphate hydrate and then separating out a chlorine salt of the alkali metal or the ammonium from a remaining liquid-phase material, and finally carrying out a regeneration reaction on the magnesium phosphate hydrate and the chlorine salt of the alkali metal or the ammonium.

A renewable magnesium removing agent and its use in a preparation of a low-magnesium lithium-rich brine are provided. The magnesium removing agent includes a magnesium phosphate double salt of an alkali metal or ammonium. A regeneration of the magnesium removing agent is realized by adding the magnesium removing agent into Mg.sup.2+-containing chloride salt solution, wherein Mg.sup.2+ in the chloride salt solution and the magnesium removing agent are subjected to a magnesium removing reaction to form a solid-phase reaction product and carrying out a solid-liquid separation on an obtained mixed reaction product after the magnesium removing reaction is ended to separate the solid-phase material comprising a magnesium phosphate hydrate and then separating out a chlorine salt of the alkali metal or the ammonium from a remaining liquid-phase material, and finally carrying out a regeneration reaction on the magnesium phosphate hydrate and the chlorine salt of the alkali metal or the ammonium.

The present invention relates to a method for producing lithium salts, such as lithium hydroxide and lithium halides, wherein the lithium salts obtained are substantially free of water and optionally other impurities, such as lithium carbonate and/or lithium oxide. Moreover, the present invention refers to lithium salts, such as lithium hydroxide and lithium halides obtainable by said method, as well as their use for the production of e.g. solid electrolytes, lithium metal or lithium carbonate.

The present invention relates to a method for producing lithium salts, such as lithium hydroxide and lithium halides, wherein the lithium salts obtained are substantially free of water and optionally other impurities, such as lithium carbonate and/or lithium oxide. Moreover, the present invention refers to lithium salts, such as lithium hydroxide and lithium halides obtainable by said method, as well as their use for the production of e.g. solid electrolytes, lithium metal or lithium carbonate.

An active material contains: a compound containing lithium (Li) element, sulfur (S) element, and an element M and containing a crystalline phase having an argyrodite-type crystal structure; and a conductive material dispersed on the surface or in the interior of particles of the compound. The element M represents phosphorus (P) element or the like. The active material is a composite material of the compound and the conductive material. It is preferable that the conductive material is a carbon material or a metallic material. It is also preferable that the content of the lithium element in the active material is from 10 to 25% by mass.

An active material contains: a compound containing lithium (Li) element, sulfur (S) element, and an element M and containing a crystalline phase having an argyrodite-type crystal structure; and a conductive material dispersed on the surface or in the interior of particles of the compound. The element M represents phosphorus (P) element or the like. The active material is a composite material of the compound and the conductive material. It is preferable that the conductive material is a carbon material or a metallic material. It is also preferable that the content of the lithium element in the active material is from 10 to 25% by mass.

Described are a solid material which has ionic conductivity for lithium ions, a process for preparing said solid material, a use of said solid material as a solid electrolyte for an electrochemical cell, a solid structure selected from the group consisting of a cathode, an anode and a separator for an electrochemical cell comprising the solid material, and an electrochemical cell comprising such solid structure.

Described are a solid material which has ionic conductivity for lithium ions, a process for preparing said solid material, a use of said solid material as a solid electrolyte for an electrochemical cell, a solid structure selected from the group consisting of a cathode, an anode and a separator for an electrochemical cell comprising the solid material, and an electrochemical cell comprising such solid structure.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.