WO2024078386A1 - A method and device for preparing high-purity lithium hydroxide based on lithium-ion solid-state electrolyte - Google Patents
A method and device for preparing high-purity lithium hydroxide based on lithium-ion solid-state electrolyte Download PDFInfo
- Publication number
- WO2024078386A1 WO2024078386A1 PCT/CN2023/123190 CN2023123190W WO2024078386A1 WO 2024078386 A1 WO2024078386 A1 WO 2024078386A1 CN 2023123190 W CN2023123190 W CN 2023123190W WO 2024078386 A1 WO2024078386 A1 WO 2024078386A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- lithium
- electrolysis
- cathode
- lithium hydroxide
- anode
- Prior art date
Links
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 title claims abstract description 222
- 238000000034 method Methods 0.000 title claims abstract description 56
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 38
- 239000003792 electrolyte Substances 0.000 title claims abstract description 12
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 97
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 74
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 48
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 48
- 150000003839 salts Chemical class 0.000 claims abstract description 30
- 238000006243 chemical reaction Methods 0.000 claims abstract description 23
- 239000002001 electrolyte material Substances 0.000 claims abstract description 17
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 48
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 46
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 claims description 29
- 229910052757 nitrogen Inorganic materials 0.000 claims description 24
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 20
- 238000006460 hydrolysis reaction Methods 0.000 claims description 18
- 230000007062 hydrolysis Effects 0.000 claims description 17
- 239000007784 solid electrolyte Substances 0.000 claims description 17
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 15
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 14
- GLXDVVHUTZTUQK-UHFFFAOYSA-M lithium hydroxide monohydrate Substances [Li+].O.[OH-] GLXDVVHUTZTUQK-UHFFFAOYSA-M 0.000 claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 12
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 12
- 239000012535 impurity Substances 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 10
- PQVSTLUFSYVLTO-UHFFFAOYSA-N ethyl n-ethoxycarbonylcarbamate Chemical compound CCOC(=O)NC(=O)OCC PQVSTLUFSYVLTO-UHFFFAOYSA-N 0.000 claims description 10
- 229940040692 lithium hydroxide monohydrate Drugs 0.000 claims description 10
- 239000001301 oxygen Substances 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 239000011780 sodium chloride Substances 0.000 claims description 10
- 238000002360 preparation method Methods 0.000 claims description 8
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 claims description 6
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 6
- 229910002804 graphite Inorganic materials 0.000 claims description 6
- 239000010439 graphite Substances 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 229910052697 platinum Inorganic materials 0.000 claims description 6
- 229910052725 zinc Inorganic materials 0.000 claims description 6
- 239000011701 zinc Substances 0.000 claims description 6
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 5
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 claims description 5
- 239000001103 potassium chloride Substances 0.000 claims description 5
- 235000011164 potassium chloride Nutrition 0.000 claims description 5
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 claims 8
- BHZCMUVGYXEBMY-UHFFFAOYSA-N trilithium;azanide Chemical compound [Li+].[Li+].[Li+].[NH2-] BHZCMUVGYXEBMY-UHFFFAOYSA-N 0.000 description 40
- 159000000002 lithium salts Chemical class 0.000 description 26
- 229910003002 lithium salt Inorganic materials 0.000 description 25
- 239000000243 solution Substances 0.000 description 25
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 19
- 229910001947 lithium oxide Inorganic materials 0.000 description 17
- 239000000463 material Substances 0.000 description 15
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 14
- 239000001257 hydrogen Substances 0.000 description 13
- 229910052739 hydrogen Inorganic materials 0.000 description 13
- 229910021525 ceramic electrolyte Inorganic materials 0.000 description 12
- 230000008569 process Effects 0.000 description 12
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 11
- 239000012267 brine Substances 0.000 description 11
- 239000000047 product Substances 0.000 description 11
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 11
- 238000005516 engineering process Methods 0.000 description 10
- 239000012528 membrane Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 229910021529 ammonia Inorganic materials 0.000 description 8
- 239000006260 foam Substances 0.000 description 8
- 239000010935 stainless steel Substances 0.000 description 8
- 229910001220 stainless steel Inorganic materials 0.000 description 8
- 150000002500 ions Chemical class 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 6
- 239000006227 byproduct Substances 0.000 description 6
- 239000000460 chlorine Substances 0.000 description 6
- 229910052801 chlorine Inorganic materials 0.000 description 6
- 238000001914 filtration Methods 0.000 description 6
- 238000002386 leaching Methods 0.000 description 6
- 239000003566 sealing material Substances 0.000 description 6
- 239000002699 waste material Substances 0.000 description 6
- 150000001768 cations Chemical class 0.000 description 5
- 238000001704 evaporation Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 239000011777 magnesium Substances 0.000 description 5
- 229910052749 magnesium Inorganic materials 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 4
- 238000000354 decomposition reaction Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 229910020363 KCl—MgCl2 Inorganic materials 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- RJEIKIOYHOOKDL-UHFFFAOYSA-N [Li].[La] Chemical compound [Li].[La] RJEIKIOYHOOKDL-UHFFFAOYSA-N 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 239000013043 chemical agent Substances 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 238000002425 crystallisation Methods 0.000 description 3
- 230000008025 crystallization Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- GCICAPWZNUIIDV-UHFFFAOYSA-N lithium magnesium Chemical compound [Li].[Mg] GCICAPWZNUIIDV-UHFFFAOYSA-N 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 238000005341 cation exchange Methods 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 239000013067 intermediate product Substances 0.000 description 2
- 229910000664 lithium aluminum titanium phosphates (LATP) Inorganic materials 0.000 description 2
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Inorganic materials [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 description 2
- 229940110728 nitrogen / oxygen Drugs 0.000 description 2
- 238000005580 one pot reaction Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000008247 solid mixture Substances 0.000 description 2
- RBTVSNLYYIMMKS-UHFFFAOYSA-N tert-butyl 3-aminoazetidine-1-carboxylate;hydrochloride Chemical compound Cl.CC(C)(C)OC(=O)N1CC(N)C1 RBTVSNLYYIMMKS-UHFFFAOYSA-N 0.000 description 2
- 231100000331 toxic Toxicity 0.000 description 2
- 230000002588 toxic effect Effects 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910014863 CaCl2—MgCl2 Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- CVJYOKLQNGVTIS-UHFFFAOYSA-K aluminum;lithium;titanium(4+);phosphate Chemical compound [Li+].[Al+3].[Ti+4].[O-]P([O-])([O-])=O CVJYOKLQNGVTIS-UHFFFAOYSA-K 0.000 description 1
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 1
- 229910001863 barium hydroxide Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000000909 electrodialysis Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000003014 ion exchange membrane Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 239000007774 positive electrode material Substances 0.000 description 1
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Inorganic materials [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 1
- 235000010333 potassium nitrate Nutrition 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- SWGJCIMEBVHMTA-UHFFFAOYSA-K trisodium;6-oxido-4-sulfo-5-[(4-sulfonatonaphthalen-1-yl)diazenyl]naphthalene-2-sulfonate Chemical compound [Na+].[Na+].[Na+].C1=CC=C2C(N=NC3=C4C(=CC(=CC4=CC=C3O)S([O-])(=O)=O)S([O-])(=O)=O)=CC=C(S([O-])(=O)=O)C2=C1 SWGJCIMEBVHMTA-UHFFFAOYSA-K 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/02—Hydrogen or oxygen
- C25B1/04—Hydrogen or oxygen by electrolysis of water
- C25B1/042—Hydrogen or oxygen by electrolysis of water by electrolysis of steam
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/14—Alkali metal compounds
- C25B1/16—Hydroxides
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/09—Fused bath cells
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
Definitions
- This application relates to the field of lithium chloride preparation technology. Specifically, it relates to a method and device for preparing high-purity lithium hydroxide based on lithium ion solid electrolyte.
- Lithium hydroxide is an important material for many lithium products, and is widely used in the preparation of lithium-based lubricants, positive electrode materials of ternary lithium battery, and additives in electrolytes of alkaline battery, etc. With the rapid development of the new energy industry in recent years, ternary electrode materials have attracted widespread attention due to their high energy density and other advantages. As a key basic material, the demand for lithium hydroxide has significantly increased globally. China's lithium resources are mainly concentrated in salt lake brine, with lithium resources in salt lakes in Qinghai and China accounting for about 80%of the total lithium resources in China. However, salt lake lithium resources generally have the characteristics of low lithium content, high magnesium-lithium ratio, and fragile surrounding ecological environment, making it difficult to develop and utilize these resources.
- CN202210731726.7 discloses a method for preparing lithium hydroxide and boron acid by high-magnesium-to-magnesium ratio brine.
- the method includes deep purification of the rich lithium brine obtained, and then using bipolar membrane electrodialysis technology to treat the refined rich lithium brine, thus obtaining an alkaline solution containing lithium hydroxide and sodium hydroxide in the alkali chamber, a dilute acid solution in the acid chamber, and a high-boron salt solution in the salt chamber.
- the crude lithium hydroxide product is obtained by separating lithium hydroxide and sodium hydroxide from the alkaline solution, and the battery-grade lithium hydroxide product is obtained by evaporation, centrifugation, washing, and drying of the crude lithium hydroxide product.
- CN202210446706.5 discloses a method for preparing lithium hydroxide from lithium waste materials, including the following steps: Stage 1: collect the lithium waste materials and allow them to air-dry to obtain stable lithium materials; Stage 2: dissolve the stable lithium materials in acid to obtain a lithium-containing leaching solution; Stage 3: adjust the pH of the lithium-containing leaching solution to 7-8, purify it to obtain a first purified solution; Stage 4: perform cold crystallization to separate saltpeter and a second purified solution from the first purified solution; Stage 5: refine, concentrate and crystallize the second purified solution with a chelating agent to obtain lithium hydroxide.
- CN202210229992. X discloses a method for producing battery-grade lithium hydroxide by recycling waste ternary lithium batteries. The method involves mixing and roasting pre-treated waste ternary positive electrode powder with sulfate to convert lithium into soluble lithium sulfate, followed by leaching with pure water to obtain a lithium-containing solution. The water leaching solution is then processed through a series of procedures including lithium salt transformation, impurity removal, evaporation, and crystallization to produce lithium hydroxide.
- CN202210073174.5 discloses a method for preparing lithium hydroxide from lithium tailings of salt lake.
- the method includes: (1) adding calcium hydroxide to the lithium tailings, heating and stirring, filtering, and taking the liquid to obtain a first treatment solution; (2) adding oxalic acid to the first treatment solution, heating and stirring, filtering, and taking the liquid to obtain a second treatment solution; (3) adding barium hydroxide to the second treatment solution, heating and stirring, filtering, and taking the liquid to obtain a third treatment solution; (4) adding sodium hydroxide to the third treatment solution, heating and stirring, filtering, and taking the liquid to obtain a fourth treatment solution; (5) evaporating and drying the fourth treatment solution to obtain a solid mixture; (6) heating the solid mixture to 650-700°C, filtering, taking the liquid, cooling to 400-450°C, filtering, and taking the solid to obtain lithium chloride; (7) electrolyzing the lithium chloride to obtain lithium hydroxide.
- CN201910381141.5 discloses a method for directly electrolyzing lithium chloride to prepare battery-grade lithium hydroxide.
- the method includes refining the lithium chloride solution, adding the refined lithium chloride solution to the anode chamber of a bipolar natural circulation ion membrane electrolysis cell, where the ion exchange membrane of the bipolar natural circulation ion membrane electrolysis cell is a cation exchange membrane.
- a lithium hydroxide solution with a mass percentage concentration of 5.5%-7.5% is added to the cathode chamber of the bipolar natural circulation ion membrane electrolysis cell, followed by the addition of pure water to adjust the mass percentage concentration of the lithium hydroxide solution to 4.9%-6.5%.
- the present disclosure requires lower-grade materials, allowing for the use of lithium salt as material, which can effectively separate lithium and magnesium. Moreover, the present disclosure only requires small amount of chemical reagent, and the electrolysis process does not generate chlorine, thereby eliminating environmental pollution and safety hazards. This method can be applied to the development and utilization of lithium resources, including salt lake brine.
- CN201410175543.7 discloses a method for preparing lithium hydroxide by electrolyzing brine from salt lakes, including the following steps: (1) concentrating the original brine containing lithium through solar evaporation in a salt field to obtain brine with a high magnesium-lithium ratio; (2) refining the high magnesium-lithium ratio brine after impurity removal; (3) using the refined brine as the anode liquid and using the lithium hydroxide solution as the cathode liquid for electrolysis, obtaining a lithium hydroxide monohydrate solution through a cation exchange membrane in the cathode chamber; (4) concentrating the lithium hydroxide monohydrate solution through evaporation, cooling, crystallization, washing and drying to obtain lithium hydroxide monohydrate.
- the technology has high requirements for materials, requiring the concentration and impurity removal of salt lake brine before use, and the electrolysis process generates chlorine, posing environmental and safety risks.
- the present disclosure has lower requirements for materials, can use low-purity lithium salt as materials, can effectively separate lithium and magnesium, requires fewer chemical reagents, and the electrolysis process does not generate chlorine, which is environmentally friendly and pollution-free.
- US20210324527A1 discloses a method for preparing lithium hydroxide, comprising: providing a mixture of lithium chloride and water to an electrolytic reaction chamber, wherein the electrolytic reaction chamber comprises an ion-selective membrane separating a first volume from a second volume, wherein the ion-selective membrane selectively allows lithium ions to pass through while inhibiting hydroxide and chloride ions from passing through the membrane; an anode located in the first volume; and a cathode located in the second volume, wherein the mixture is provided to the first volume; water or a lithium hydroxide aqueous solution is provided to the second volume; a selected voltage is provided from a power source to the anode and cathode, producing chlorine from the first volume, producing hydrogen from the second volume, and producing a lithium hydroxide solution from the second volume.
- This technology requires high-quality electrolytic materials that impurities such as calcium and magnesium ions must be removed in advance. Chlorine is produced during the electrolysis process, posing environmental and safety risks. Moreover, the ion-selective membrane used in the device is used in an aqueous solution and can only inhibit hydroxide and chloride ions from passing through, while it cannot inhibit other metal cations from passing through, thereby affecting the purity of the electrolysis product. However, the present disclosure can directly use low-purity lithium salts as materials. The lithium ion ceramic solid-state electrolyte used has highly selective permeability for lithium ions, and impurities such as other metal cations cannot pass through, thereby ensuring the purity of the product. Additionally, the amount of chemical reagents used is small, the cost is low, and no chlorine is generated during the process, resulting in minimal environmental damages and pollution-free production.
- a method for preparing lithium hydroxide includes: in an electrolysis, reducing water vapor at a low potential in presence of lithium ions to generate LiOH by using a lithium-containing molten salt as an electrolyte material at an reaction temperature of 150°C-450°C, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm 2 , wherein a solid-state electrolyte is disposed between an anode and a cathode for the electrolysis, and the water vapor is introduced at the cathode during the electrolysis.
- the electrolysis is a one-step reaction.
- a sacrificial electrode of the anode includes one or more of aluminum, zinc, and iron.
- an inert electrode of the cathode is a porous and includes one or more of graphite, nickel, nickel-iron alloy, and platinum.
- the lithium-containing molten salt comprises impurities including one or more of potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl 2 ) , and magnesium chloride (MgCl 2 ) .
- KCl potassium chloride
- NaCl sodium chloride
- CaCl 2 calcium chloride
- MgCl 2 magnesium chloride
- an electrolytic device for preparation of lithium hydroxide includes an anode, a cathode, and a solid electrolyte disposed between the anode and the cathode, wherein the electrolytic device is configured to use a lithium-containing molten salt as an electrolyte material and perform electrolysis at an reaction temperature of 150°C-450°C, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm 2 , wherein water vapor is introduced at the cathode during the electrolysis.
- the preparation of lithium hydroxide is a one-step reaction.
- a method for preparing lithium hydroxide includes: in an electrolysis, reducing N 2 or O 2 in presence of lithium ions to form Li 3 N or Li 2 O by using a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150°C-450°C, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm 2 , wherein a solid electrolyte is placed between an anode and a cathode for electrolysis, and nitrogen or oxygen is directed to pass through the cathode in the electrolysis.
- the method further includes reacting Li 3 N or Li 2 O with water to produce lithium hydroxide monohydrate with a purity of 95.0 wt%-99.99 wt%.
- reducing N 2 or O 2 in presence of lithium ions includes directing N 2 or O 2 to pass through the cathode such that N 2 or O 2 receives electrons on an inert electrode of the cathode and the lithium ions combine with the reduced nitrogen or oxygen to form Li 3 N or Li 2 O.
- reacting Li 3 N or Li 2 O with water includes by collecting and transferring Li 3 N or Li 2 O to a hydrolysis chamber, into which water vapor is introduced, and Li 3 N or Li 2 O is hydrolyzed to form the lithium hydroxide monohydrate.
- a sacrificial electrode of the anode includes one or more of aluminum, zinc, and iron.
- an inert electrode of the cathode includes one or more of graphite, nickel, nickel-iron alloy, and platinum.
- an electrolysis device for preparing lithium hydroxide.
- the device includes: an anode, a cathode, a solid electrolyte, and a hydrolysis chamber.
- the electrolysis device is configured to reduce N 2 or O 2 in presence of lithium ions to form Li 3 N or Li 2 O by using a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150°C-450°C, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm 2 , wherein the solid electrolyte is placed between the anode and the cathode for electrolysis, and nitrogen or oxygen is directed to pass through the cathode in the electrolysis.
- Li 3 N or Li 2 O is reacted with water in the hydrolysis chamber to produce lithium hydroxide monohydrate with a purity of 95.0 wt%-99.99 wt%.
- FIG. 1 shows an example configuration of an apparatus for carrying out the one-step technology according to one embodiment of the present disclosure, in which (1) represents the molten lithium salt, (2) represents the sacrificial electrode, (3) represents the sealing material, (4) represents the LLZTO, (5) represents the porous inert electrode, (6) represents the water vapor inlet, (7) represents the water vapor /hydrogen outlet, and (8) represents the lithium hydroxide collection chamber.
- FIGs. 2A and 2B show an example configuration of an apparatus for carrying out the two-step technology according to one embodiment of the present disclosure, in which (9) represents the molten lithium salt, (10) represents the sacrificial electrode, (11) represents the sealing material, (12) represents the LLZTO, (13) represents the porous inert electrode, (14) represents the nitrogen/purified air inlet, (15) represents the nitrogen/purified air outlet, (16) represents the lithium nitride/lithium oxide collection chamber, (17) represents the water vapor inlet, (18) represents the lithium nitride/lithium oxide feed, (19) represents the water vapor outlet, and (20) represents the lithium hydroxide collection chamber.
- (9) represents the molten lithium salt
- (10) represents the sacrificial electrode
- (11) represents the sealing material
- (12) represents the LLZTO
- (13) represents the porous inert electrode
- (14) represents the nitrogen/purified air inlet
- (15) represents the nitrogen/purified air outlet
- (16) represents the lithium
- FIG. 3 shows an example electrolysis apparatus, in which (21) represents the glass seal, (22) represents the LLZTO tube, (23) represents the stainless steel foam, (24) represents the water vapor inlet, (25) represents the sacrificial electrode, (26) represents the molten lithium salt, (27) represents the cathode stainless steel shell, (28) represents the water vapor/hydrogen outlet, and (29) represents the lithium hydroxide collection chamber.
- FIG. 4 shows another example electrolysis apparatus, in which (30) represents the glass seal, (31) represents the molten lithium salt, (32) represents the sacrificial electrode, (33) represents the LLZTO, (34) represents the stainless foam, (35) represents the water vapor inlet, (36) represents the water vapor/hydrogen outlet, and (37) represents the lithium hydroxide collection chamber.
- FIGs. 5A and 5B show yet another example electrolysis apparatus, in which (38) represents the glass seal, (39) represents the LLZTO, (40) represents the stainless steel foam, (41) represents the nitrogen/purified air inlet, (42) represents the sacrificial electrode, (43) represents the molten lithium salt, (44) represents the cathode stainless steel shell, (45) represents the nitrogen/purified air outlet, (46) represents the lithium nitride/lithium oxide collection chamber, (47) represents the water vapor inlet, (48) represents the lithium nitride/lithium oxide feed, (49) represents the water vapor/ammonia outlet, and (50) represents the lithium hydroxide collection chamber.
- (38) represents the glass seal
- (39) represents the LLZTO
- (40) represents the stainless steel foam
- (41) represents the nitrogen/purified air inlet
- (42) represents the sacrificial electrode
- (43) represents the molten lithium salt
- (44) represents the cathode stainless steel shell
- (45) represents the
- FIGs. 6A and 6B show yet another example electrolysis apparatus, in which (51) represents the glass seal, (52) represents the molten lithium salt, (53) represents the sacrificial electrode, (54) represents the LLZTO, (55) represents the stainless steel foam, (56) represents the nitrogen/purified air inlet, (57) represents the nitrogen/purified air outlet, (58) represents the lithium nitride/lithium oxide collection chamber, (59) represents the water vapor inlet, (60) represents the lithium nitride/lithium oxide feed, (61) represents the water vapor/ammonia outlet, and (62) represents the lithium hydroxide collection chamber.
- FIGs. 7A and 7B show the electrochemical curves for the electrolysis process carried out in the electrolysis apparatus as shown in FIGs. 6A and 6B.
- FIG. 1 shows an example configuration of an apparatus for carrying out the one-step technology according to one embodiment of the present disclosure, in which (1) represents the molten lithium salt, (2) represents the sacrificial electrode, (3) represents the sealing material, (4) represents the LLZTO, (5) represents the porous inert electrode, (6) represents the water vapor inlet, (7) represents the water vapor /hydrogen outlet, and (8) represents the lithium hydroxide collection chamber.
- FIG. 2 shows an example configuration of an apparatus for carrying out the two-step technology according to one embodiment of the present disclosure, in which (9) represents the molten lithium salt, (10) represents the sacrificial electrode, (11) represents the sealing material, (12) represents the LLZTO, (13) represents the porous inert electrode, (14) represents the nitrogen/purified air inlet, (15) represents the nitrogen/purified air outlet, (16) represents the lithium nitride/lithium oxide collection chamber, (17) represents the water vapor inlet, (18) represents the lithium nitride/lithium oxide feed, (19) represents the water vapor outlet, and (20) represents the lithium hydroxide collection chamber.
- (9) represents the molten lithium salt
- (10) represents the sacrificial electrode
- (11) represents the sealing material
- (12) represents the LLZTO
- (13) represents the porous inert electrode
- (14) represents the nitrogen/purified air inlet
- (15) represents the nitrogen/purified air outlet
- (16) represents the lithium nitride
- the present disclosure proposes a new method and apparatus for extracting and preparing high-purity lithium hydroxide from low-purity lithium salts, which has low requirements for the purity of the materials, can efficiently separate magnesium and lithium, and only uses a small amount of chemical agents and has minimal impact on the environment. It can be used for the development and utilization of lithium resources, including salt lake brines.
- the present disclosure proposes a new method and apparatus for extracting and preparing high-purity lithium hydroxide from low-purity lithium salts, which requires lower purity for materials, can efficiently separate magnesium and lithium, and has smaller chemical agent usage and ecological damages.
- the method utilizes the characteristic of high selective permeability of Li+ by lithium ion ceramic solid electrolyte, which can effectively prevent impurity ions from passing through, and realizes the production of high-purity lithium hydroxide products from low-purity lithium salt materials through reasonable electrode design.
- the reaction is carries out at a temperature of 150°C-450°C; the electrolysis voltage is between 1.5V-3V, and the current density is 1-100mA/cm 2 .
- the lithium ion ceramic solid electrolyte includes but is not limited to lithium lanthanum zirconate (LLZO) , tantalum-doped lithium lanthanum zirconate (LLZTO) , niobium-doped lithium lanthanum zirconate (LLZNO) , and lithium aluminum titanium phosphate (LATP) .
- the mass fraction of lithium in low-purity lithium salts is between 0.1%-16%, where the low-purity lithium salts may include impurities such as potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl 2 ) , and magnesium chloride (MgCl 2 ) , among others.
- KCl potassium chloride
- NaCl sodium chloride
- CaCl 2 calcium chloride
- MgCl 2 magnesium chloride
- the present disclosure provides a method for one-step preparation of lithium hydroxide.
- the method is based on the reduction of water vapor at a low potential, combined with the reaction of lithium ions to generate LiOH.
- the process directly produces LiOH using a lithium-containing molten salt as an electrolyte material at a temperature of 150°C-450°C, with an electrolysis voltage of 1.5V-3V and a current density of 1-100mA/cm 2 .
- a solid-state electrolyte is placed between the anode and the cathode of the electrolysis, and water vapor is directed to pass through the cathode in the electrolysis.
- the sacrificial electrode plate at the electrolytic anode loses electrons to form metal cations that enter the molten salt system, and at the same time, lithium ions in the molten salt system move towards the solid electrolyte through which they can reach the electrolytic cathode.
- Water vapor is directed to pass through the cathode in the electrolysis, where H 2 O molecules are reduced to H 2 on the inert electrode by gaining electrons, leaving OH-to combine with lithium ions to form high-purity LiOH.
- the reaction is carried out at a temperature of 200°C-400°C, or 250°C-350°C, or 280°C-300°C, with an electrolysis voltage of 1.8V-2.5V, or 2.0V-2.3V, and a current density of 10-900mA/cm 2 , or 30-800mA/cm 2 , or 50-550mA/cm 2 .
- the sacrificial electrode of the anode includes but is not limited to aluminum, zinc, and iron.
- the inert electrode at the cathode is a porous electrode, including but not limited to graphite, nickel, nickel-iron alloy, and platinum.
- the lithium-containing molten salt is a low-purity lithium salt, with impurities including but not limited to potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl 2 ) , and magnesium chloride (MgCl 2 ) .
- impurities including but not limited to potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl 2 ) , and magnesium chloride (MgCl 2 ) .
- the mass fraction of lithium element in the low-purity lithium salt is 0.1%-16%.
- Me-ne - Me n+ ;
- the advantage of the disclosed one-step method for preparing lithium hydroxide is that it is simple and can obtain high-purity lithium hydroxide from low-concentration lithium-containing molten salts.
- the by-product is economically valuable hydrogen, and this method does not produce toxic or harmful waste to the environment.
- the present disclosure also provides an electrolysis device for the one-step preparation of lithium hydroxide.
- the device includes an anode, a cathode, and a solid electrolyte using lithium-containing molten salt as an electrolyte material and performs electrolysis at a reaction temperature of 150°C-450°C, an electrolysis voltage of 1.5V-3V, and a current density of 1-100mA/cm 2 .
- a solid electrolyte is placed between the anode and cathode, and water vapor is introduced at the cathode during electrolysis.
- the cathode is an inert porous electrode.
- the electrolytic device includes a lithium hydroxide collection chamber.
- the electrolysis device includes a water vapor inlet and a water vapor/hydrogen outlet.
- the electrolysis device includes sealing materials.
- the present disclosure also provides a method for preparing lithium hydroxide using a two-step process.
- the method includes:
- Step 1 N 2 and O 2 are reduced and combined with lithium ions to form Li 3 N or Li 2 O at low potentials use a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150°C-450°C, an electrolysis voltage of 1.5V-3V, and a current density of 1-100mA/cm 2 .
- a solid electrolyte is placed between the anode and the cathode during electrolysis, and nitrogen or oxygen is directed to pass through the cathode during the reaction.
- Step 2 React the generated Li 3 N or Li 2 O with water to generate lithium hydroxide monohydrate with a purity of 95.0%-99.99%
- the sacrificial electrode plate at the anode of the electrolysis loses electrons to form metal cations that enter the molten salt system, while the lithium ions in the molten salt system move towards the solid-state electrolyte and pass through the solid-state electrolyte to reach the electrolysis cathode.
- the sacrificial electrode plate at the anode of the electrolysis loses electrons to form metal cations that enter the raw material molten salt system, while lithium ions in the molten salt system move towards the solid electrolyte and reach the electrolysis cathode through the solid electrolyte.
- nitrogen or purified air excluding CO 2 , SO x and NO x , etc.
- N 2 and O 2 molecules obtain electrons on the inert electrode of the electrolysis cathode and combine with lithium ions to form Li 3 N and Li 2 O.
- the generated Li3N or Li 2 O is collected and transferred to the hydrolysis chamber.
- Water vapor is introduced into the hydrolysis chamber, and Li 3 N and Li 2 O spontaneously are hydrolyzed to produce high-purity monohydrate lithium hydroxide with a purity of 95.0%-99.99%.
- the temperature of the electrolysis reaction is at 200°C-400°C, or 250°C-350°C, or 280°C-300°C
- the electrolysis voltage is at 1.8V-2.5V, or 2.0V-2.3V
- the current density is at 10-900mA/cm 2 , or 30-800mA/cm 2 , or 50-550mA/cm 2 .
- the sacrificial anode of the anode includes but is not limited to aluminum, zinc, and iron
- the inert electrode of the cathode includes but is not limited to graphite, nickel, nickel-iron alloy, and platinum.
- the lithium-containing molten salt in the present invention is low-purity lithium salt, with impurities including but not limited to potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl 2 ) , magnesium chloride (MgCl 2 ) , etc.
- impurities including but not limited to potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl 2 ) , magnesium chloride (MgCl 2 ) , etc.
- the mass fraction of lithium element in the low-purity lithium salt is 0.1%-16%.
- the preparation of monohydrate lithium hydroxide leads to the production of lithium hydroxide.
- the present disclosure provides an electrolytic device for producing lithium hydroxide by a two-step method.
- the device includes an anode, a cathode, a solid-state electrolyte, and a hydrolysis chamber.
- the electrolyte material is a molten salt containing lithium
- the first step of the electrolytic reaction is operated at a temperature of 150°C-450°C, a voltage of 1.5V-3V, and a current density of 1-100mA/cm 2 .
- a solid-state electrolyte is set between the anode and the cathode during electrolysis, and nitrogen or oxygen is introduced at the cathode.
- Li 3 N and Li 2 O undergo a second-step hydrolysis reaction.
- the cathode is an inert porous electrode.
- the electrolysis device comprises a nitrogen/oxygen (purified air inlet) inlet and a nitrogen/oxygen (purified air inlet) outlet.
- the electrolytic cell includes a lithium hydroxide collection chamber.
- the electrolysis device includes sealing materials.
- the hydrolysis chamber comprises a water vapor inlet.
- the water decomposition chamber includes a water vapor or ammonia outlet.
- the advantage of the two-step method for producing lithium hydroxide is that the process conditions are mild and safe, and high-purity lithium hydroxide can be extracted from low-concentration lithium-containing molten salt.
- the by-product, ammonia also has certain economic value, and generates no toxic or harmful waste.
- FIG. 3 shows an example electrolysis apparatus, in which LLZTO lithium-ion ceramic electrolyte tube or LLZTO tube 22 is employed as the ceramic electrolyte, and an aluminum rod is employed as the sacrificial electrode 25.
- the electrolyte material or the molten lithium salt 26 used in this example is LiCl-AlCl 3 -NaCl-KCl-MgCl 2 (molar ratio of 51.7: 43.1: 1.7: 1.7: 1.8) molten salt.
- the electrolysis reaction is carried out at a temperature of 250°C and with an electrolysis current of 50mA.
- the generated hydrogen and excess water vapor are discharged through the water vapor/hydrogen outlet 28 as by-products.
- FIG. 4 shows another example electrolysis apparatus.
- LLZTO lithium-ion ceramic electrolyte sheet ( ⁇ 22*4mm) is used as the ceramic electrolyte or LLZTO 33, and aluminum sheet is used as the sacrificial electrode 32.
- the electrolyte material is a molten lithium salt 31 consisting of LiCl-AlCl 3 -CaCl 2 -KCl-MgCl 2 (molar ratio 39.6: 39.6: 2.0: 6.5: 12.3) .
- the reacting temperature is 250°C, and the electrolysis current is 50mA.
- the lithium ions in the anode compartment enter the lithium hydroxide collection chamber 37 through the LLZTO ceramic electrolyte sheet or LLZTO 33 under the drive of an external power supply.
- the one-hydrate lithium hydroxide is collected in the lithium hydroxide collection chamber 37, with a purity of 98.2%.
- the generated hydrogen and excess water vapor are discharged through the water vapor/hydrogen outlet 36 as by-products.
- FIGs. 5A and 5B This is a description of a setup for a two-step electrolysis process, as shown in FIGs. 5A and 5B.
- the left side (FIG. 5A) of the setup is an electrolysis cell where the first step of electrolysis takes place.
- the ceramic electrolyte used is an LLZTO lithium-ion ceramic electrolyte tube 39, and the sacrificial electrode 42 is an aluminum rod .
- the electrolyte materials consist of a molten lithium salt 43, a mixture of LiCl-AlCl 3 -NaCl-CaCl 2 -MgCl 2 (molar ratio of 20.8: 37.9: 10.4: 8.5: 22.4) .
- the reacting temperature of the electrolysis cell is 250°C, and the electrolysis current is 50mA.
- Lithium ions in the anode chamber are driven by an external power source through the LLZTO ceramic electrolyte tube 39 and enter the cathode chamber 46 of the electrolysis cell.
- the lithium ions react with oxygen in the nitrogen or purified air that is introduced through the nitrogen/purified air inlet 41.
- the intermediate products, Li 3 N and Li 2 O, are collected in the electrolysis cell cathode chamber or lithium nitride/lithium oxide collection chamber 46. Excess nitrogen or purified air is discharged through the electrolysis cell outlet or the nitrogen/purified air outlet 45. The collected lithium nitride or lithium oxide is transferred to the water decomposition tank on the right side of the setup (as shown in FIG. 5B) through the feed inlet or the lithium nitride/lithium oxide feed 48.
- the resulting monohydrated lithium hydroxide is collected as a product in the lithium hydroxide collection chamber 50 of the decomposition tank and has a purity of 99.0%. Excess water vapor and generated ammonia are discharged through the water vapor/ammonia outlet 49 as by-products.
- LLZTO lithium ion ceramic electrolyte sheet or LLZTO 54 ( ⁇ 22*4mm) is used as the ceramic electrolyte, and the aluminum sheet or the sacrificial electrode 53 is used as the sacrificial anode.
- the electrolyte materials are LiCl-AlCl 3 -NaCl-KCl-MgCl 2 (molar ratio 40.2: 38.1: 7.9: 5.8: 8.0) molten lithium salt 52.
- the electrolysis cell reacts at a temperature of 300°C and with an electrolysis current of 100mA.
- lithium ions enter the lithium nitride/lithium oxide collection chamber 58 through the LLZTO ceramic electrolyte sheet or the LLZTO 54 under the drive of an external power source.
- the intermediate products Li 3 N and Li 2 O are collected in the electrolysis cell cathode compartment or the lithium nitride/lithium oxide collection chamber 58, and excess nitrogen or purified air is charged through the electrolysis cell outlet or the nitrogen/purified air outlet 57.
- the collected lithium nitride or lithium oxide is transferred to the right-side hydrolysis tank in FIG. 6B through the hydrolysis tank inlet or the lithium nitride/lithium oxide feed 60.
- the resulting monohydrate lithium hydroxide is collected in the lithium hydroxide collection chamber 62 of the hydrolysis tank as the product, with a purity of 99.9%. Excess water vapor and generated ammonia are discharged through the water vapor/ammonia outlet 61 as by-products.
- FIGs. 7A and 7B The electrolysis current and cell voltage of the two-step method for preparing lithium hydroxide electrolysis cell are shown in FIGs. 7A and 7B.
- the electrolysis voltage reached 1.8V and remained stable, indicating the formation of lithium nitride at the cathode during electrolysis.
- a noticeable purple-red solid was found on the cathode current collector, which is the solid lithium nitride.
Abstract
A method for preparing lithium hydroxide includes reducing water vapor at a low potential in presence of lithium ions to generate LiOH by using a lithium-containing molten salt as an electrolyte material at an reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2. A solid-state electrolyte is disposed between an anode and a cathode for electrolysis, and the water vapor is introduced at the cathode during the electrolysis.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to Chinese Patent Application No. 202211227355.5, filed on October 9, 2022. The above application is incorporated herein by reference in its entirety.
This application relates to the field of lithium chloride preparation technology. Specifically, it relates to a method and device for preparing high-purity lithium hydroxide based on lithium ion solid electrolyte.
Lithium hydroxide is an important material for many lithium products, and is widely used in the preparation of lithium-based lubricants, positive electrode materials of ternary lithium battery, and additives in electrolytes of alkaline battery, etc. With the rapid development of the new energy industry in recent years, ternary electrode materials have attracted widespread attention due to their high energy density and other advantages. As a key basic material, the demand for lithium hydroxide has significantly increased globally. China's lithium resources are mainly concentrated in salt lake brine, with lithium resources in salt lakes in Qinghai and Tibet accounting for about 80%of the total lithium resources in China. However, salt lake lithium resources generally have the characteristics of low lithium content, high magnesium-lithium ratio, and fragile surrounding ecological environment, making it difficult to develop and utilize these resources.
CN202210731726.7 discloses a method for preparing lithium hydroxide and boron acid by high-magnesium-to-magnesium ratio brine. The method includes deep purification of the rich lithium brine obtained, and then using bipolar membrane electrodialysis technology to treat the refined rich lithium brine, thus obtaining an alkaline solution containing lithium hydroxide and sodium hydroxide in the alkali chamber, a dilute acid solution in the acid chamber, and a high-boron salt solution in the salt chamber. The crude lithium hydroxide
product is obtained by separating lithium hydroxide and sodium hydroxide from the alkaline solution, and the battery-grade lithium hydroxide product is obtained by evaporation, centrifugation, washing, and drying of the crude lithium hydroxide product.
CN202210446706.5 discloses a method for preparing lithium hydroxide from lithium waste materials, including the following steps: Stage 1: collect the lithium waste materials and allow them to air-dry to obtain stable lithium materials; Stage 2: dissolve the stable lithium materials in acid to obtain a lithium-containing leaching solution; Stage 3: adjust the pH of the lithium-containing leaching solution to 7-8, purify it to obtain a first purified solution; Stage 4: perform cold crystallization to separate saltpeter and a second purified solution from the first purified solution; Stage 5: refine, concentrate and crystallize the second purified solution with a chelating agent to obtain lithium hydroxide.
CN202210229992. X discloses a method for producing battery-grade lithium hydroxide by recycling waste ternary lithium batteries. The method involves mixing and roasting pre-treated waste ternary positive electrode powder with sulfate to convert lithium into soluble lithium sulfate, followed by leaching with pure water to obtain a lithium-containing solution. The water leaching solution is then processed through a series of procedures including lithium salt transformation, impurity removal, evaporation, and crystallization to produce lithium hydroxide.
CN202210073174.5 discloses a method for preparing lithium hydroxide from lithium tailings of salt lake. The method includes: (1) adding calcium hydroxide to the lithium tailings, heating and stirring, filtering, and taking the liquid to obtain a first treatment solution; (2) adding oxalic acid to the first treatment solution, heating and stirring, filtering, and taking the liquid to obtain a second treatment solution; (3) adding barium hydroxide to the second treatment solution, heating and stirring, filtering, and taking the liquid to obtain a third treatment solution; (4) adding sodium hydroxide to the third treatment solution, heating and stirring, filtering, and taking the liquid to obtain a fourth treatment solution; (5) evaporating and drying the fourth treatment solution to obtain a solid mixture; (6) heating the solid mixture to 650-700℃, filtering, taking the liquid, cooling to 400-450℃, filtering, and taking the solid to obtain lithium chloride; (7) electrolyzing the lithium chloride to obtain lithium hydroxide.
CN201910381141.5 discloses a method for directly electrolyzing lithium chloride to prepare battery-grade lithium hydroxide. The method includes refining the lithium chloride solution, adding the refined lithium chloride solution to the anode chamber of a bipolar natural circulation ion membrane electrolysis cell, where the ion exchange membrane of the
bipolar natural circulation ion membrane electrolysis cell is a cation exchange membrane. A lithium hydroxide solution with a mass percentage concentration of 5.5%-7.5%is added to the cathode chamber of the bipolar natural circulation ion membrane electrolysis cell, followed by the addition of pure water to adjust the mass percentage concentration of the lithium hydroxide solution to 4.9%-6.5%. Compared to existing technology, the present disclosure requires lower-grade materials, allowing for the use of lithium salt as material, which can effectively separate lithium and magnesium. Moreover, the present disclosure only requires small amount of chemical reagent, and the electrolysis process does not generate chlorine, thereby eliminating environmental pollution and safety hazards. This method can be applied to the development and utilization of lithium resources, including salt lake brine.
CN201410175543.7 discloses a method for preparing lithium hydroxide by electrolyzing brine from salt lakes, including the following steps: (1) concentrating the original brine containing lithium through solar evaporation in a salt field to obtain brine with a high magnesium-lithium ratio; (2) refining the high magnesium-lithium ratio brine after impurity removal; (3) using the refined brine as the anode liquid and using the lithium hydroxide solution as the cathode liquid for electrolysis, obtaining a lithium hydroxide monohydrate solution through a cation exchange membrane in the cathode chamber; (4) concentrating the lithium hydroxide monohydrate solution through evaporation, cooling, crystallization, washing and drying to obtain lithium hydroxide monohydrate. The technology has high requirements for materials, requiring the concentration and impurity removal of salt lake brine before use, and the electrolysis process generates chlorine, posing environmental and safety risks. Compared to this technology, the present disclosure has lower requirements for materials, can use low-purity lithium salt as materials, can effectively separate lithium and magnesium, requires fewer chemical reagents, and the electrolysis process does not generate chlorine, which is environmentally friendly and pollution-free.
US20210324527A1 discloses a method for preparing lithium hydroxide, comprising: providing a mixture of lithium chloride and water to an electrolytic reaction chamber, wherein the electrolytic reaction chamber comprises an ion-selective membrane separating a first volume from a second volume, wherein the ion-selective membrane selectively allows lithium ions to pass through while inhibiting hydroxide and chloride ions from passing through the membrane; an anode located in the first volume; and a cathode located in the second volume, wherein the mixture is provided to the first volume; water or a lithium hydroxide aqueous solution is provided to the second volume; a selected voltage is provided from a power source to the anode and cathode, producing chlorine from the first volume,
producing hydrogen from the second volume, and producing a lithium hydroxide solution from the second volume. This technology requires high-quality electrolytic materials that impurities such as calcium and magnesium ions must be removed in advance. Chlorine is produced during the electrolysis process, posing environmental and safety risks. Moreover, the ion-selective membrane used in the device is used in an aqueous solution and can only inhibit hydroxide and chloride ions from passing through, while it cannot inhibit other metal cations from passing through, thereby affecting the purity of the electrolysis product. However, the present disclosure can directly use low-purity lithium salts as materials. The lithium ion ceramic solid-state electrolyte used has highly selective permeability for lithium ions, and impurities such as other metal cations cannot pass through, thereby ensuring the purity of the product. Additionally, the amount of chemical reagents used is small, the cost is low, and no chlorine is generated during the process, resulting in minimal environmental damages and pollution-free production.
In addition, traditional methods of preparing LiOH, such as the lithium sulfate leaching method and the lithium carbonate leaching method, have high energy consumption, use large amounts of chemical agents, have high requirements for material purity, and have difficulty to produce high-quality products.
According to an aspect of the present disclosure, a method for preparing lithium hydroxide is provided. The method includes: in an electrolysis, reducing water vapor at a low potential in presence of lithium ions to generate LiOH by using a lithium-containing molten salt as an electrolyte material at an reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein a solid-state electrolyte is disposed between an anode and a cathode for the electrolysis, and the water vapor is introduced at the cathode during the electrolysis. In some embodiments, the electrolysis is a one-step reaction.
In some embodiments, a sacrificial electrode of the anode includes one or more of aluminum, zinc, and iron.
In some embodiments, an inert electrode of the cathode is a porous and includes one or more of graphite, nickel, nickel-iron alloy, and platinum.
In some embodiments, the lithium-containing molten salt comprises impurities including one or more of potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride
(CaCl2) , and magnesium chloride (MgCl2) .
According to another aspect of the present disclosure, an electrolytic device for preparation of lithium hydroxide is provided. The device includes an anode, a cathode, and a solid electrolyte disposed between the anode and the cathode, wherein the electrolytic device is configured to use a lithium-containing molten salt as an electrolyte material and perform electrolysis at an reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein water vapor is introduced at the cathode during the electrolysis. In some embodiments, the preparation of lithium hydroxide is a one-step reaction.
According to another aspect of the present disclosure, a method for preparing lithium hydroxide is provided. The method includes: in an electrolysis, reducing N2 or O2 in presence of lithium ions to form Li3N or Li2O by using a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein a solid electrolyte is placed between an anode and a cathode for electrolysis, and nitrogen or oxygen is directed to pass through the cathode in the electrolysis. The method further includes reacting Li3N or Li2O with water to produce lithium hydroxide monohydrate with a purity of 95.0 wt%-99.99 wt%.
In some embodiments, reducing N2 or O2 in presence of lithium ions includes directing N2 or O2 to pass through the cathode such that N2 or O2 receives electrons on an inert electrode of the cathode and the lithium ions combine with the reduced nitrogen or oxygen to form Li3N or Li2O.
In some embodiments, reacting Li3N or Li2O with water includes by collecting and transferring Li3N or Li2O to a hydrolysis chamber, into which water vapor is introduced, and Li3N or Li2O is hydrolyzed to form the lithium hydroxide monohydrate.
In some embodiments, a sacrificial electrode of the anode includes one or more of aluminum, zinc, and iron.
In some embodiments, an inert electrode of the cathode includes one or more of graphite, nickel, nickel-iron alloy, and platinum.
According to another aspect of the present disclosure, an electrolysis device for preparing lithium hydroxide is provided. The device includes: an anode, a cathode, a solid electrolyte, and a hydrolysis chamber. The electrolysis device is configured to reduce N2 or O2 in presence of lithium ions to form Li3N or Li2O by using a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein the solid electrolyte is placed
between the anode and the cathode for electrolysis, and nitrogen or oxygen is directed to pass through the cathode in the electrolysis. Li3N or Li2O is reacted with water in the hydrolysis chamber to produce lithium hydroxide monohydrate with a purity of 95.0 wt%-99.99 wt%.
The above and/or additional aspects and advantages of the present application will become apparent and easily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:
FIG. 1 shows an example configuration of an apparatus for carrying out the one-step technology according to one embodiment of the present disclosure, in which (1) represents the molten lithium salt, (2) represents the sacrificial electrode, (3) represents the sealing material, (4) represents the LLZTO, (5) represents the porous inert electrode, (6) represents the water vapor inlet, (7) represents the water vapor /hydrogen outlet, and (8) represents the lithium hydroxide collection chamber.
FIGs. 2A and 2B show an example configuration of an apparatus for carrying out the two-step technology according to one embodiment of the present disclosure, in which (9) represents the molten lithium salt, (10) represents the sacrificial electrode, (11) represents the sealing material, (12) represents the LLZTO, (13) represents the porous inert electrode, (14) represents the nitrogen/purified air inlet, (15) represents the nitrogen/purified air outlet, (16) represents the lithium nitride/lithium oxide collection chamber, (17) represents the water vapor inlet, (18) represents the lithium nitride/lithium oxide feed, (19) represents the water vapor outlet, and (20) represents the lithium hydroxide collection chamber.
FIG. 3 shows an example electrolysis apparatus, in which (21) represents the glass seal, (22) represents the LLZTO tube, (23) represents the stainless steel foam, (24) represents the water vapor inlet, (25) represents the sacrificial electrode, (26) represents the molten lithium salt, (27) represents the cathode stainless steel shell, (28) represents the water vapor/hydrogen outlet, and (29) represents the lithium hydroxide collection chamber.
FIG. 4 shows another example electrolysis apparatus, in which (30) represents the glass seal, (31) represents the molten lithium salt, (32) represents the sacrificial electrode, (33) represents the LLZTO, (34) represents the stainless foam, (35) represents the water vapor inlet, (36) represents the water vapor/hydrogen outlet, and (37) represents the lithium hydroxide collection chamber.
FIGs. 5A and 5B show yet another example electrolysis apparatus, in which (38)
represents the glass seal, (39) represents the LLZTO, (40) represents the stainless steel foam, (41) represents the nitrogen/purified air inlet, (42) represents the sacrificial electrode, (43) represents the molten lithium salt, (44) represents the cathode stainless steel shell, (45) represents the nitrogen/purified air outlet, (46) represents the lithium nitride/lithium oxide collection chamber, (47) represents the water vapor inlet, (48) represents the lithium nitride/lithium oxide feed, (49) represents the water vapor/ammonia outlet, and (50) represents the lithium hydroxide collection chamber.
FIGs. 6A and 6B show yet another example electrolysis apparatus, in which (51) represents the glass seal, (52) represents the molten lithium salt, (53) represents the sacrificial electrode, (54) represents the LLZTO, (55) represents the stainless steel foam, (56) represents the nitrogen/purified air inlet, (57) represents the nitrogen/purified air outlet, (58) represents the lithium nitride/lithium oxide collection chamber, (59) represents the water vapor inlet, (60) represents the lithium nitride/lithium oxide feed, (61) represents the water vapor/ammonia outlet, and (62) represents the lithium hydroxide collection chamber.
FIGs. 7A and 7B show the electrochemical curves for the electrolysis process carried out in the electrolysis apparatus as shown in FIGs. 6A and 6B.
DETAIL DESCRIPTION OF THE EMBODIMENTS
The following detailed embodiments disclosed herein are merely illustrative and are intended to further describe the exemplary embodiments of the present invention. The terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. Although exemplary embodiments are described in the present disclosure, the embodiments of the present invention are not limited to the disclosed embodiments. The disclosed embodiments are merely examples of embodiments that may be included in the claims, and other embodiments or modifications, substitutions, equivalents, or the like, of the disclosed embodiments are also within the scope of the claims.
Unless the context requires otherwise, throughout the present specification and claims, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to. ” Recitation of numeric ranges of values throughout the specification is intended to serve as a shorthand notation of referring individually to each separate value falling within the range inclusive of
the values defining the range, and each separate value is incorporated in the specification as it were individually recited herein. Additionally, the singular forms “a, ” “an” and “the” include plural referents unless the context clearly dictates otherwise.
FIG. 1 shows an example configuration of an apparatus for carrying out the one-step technology according to one embodiment of the present disclosure, in which (1) represents the molten lithium salt, (2) represents the sacrificial electrode, (3) represents the sealing material, (4) represents the LLZTO, (5) represents the porous inert electrode, (6) represents the water vapor inlet, (7) represents the water vapor /hydrogen outlet, and (8) represents the lithium hydroxide collection chamber.
FIG. 2 shows an example configuration of an apparatus for carrying out the two-step technology according to one embodiment of the present disclosure, in which (9) represents the molten lithium salt, (10) represents the sacrificial electrode, (11) represents the sealing material, (12) represents the LLZTO, (13) represents the porous inert electrode, (14) represents the nitrogen/purified air inlet, (15) represents the nitrogen/purified air outlet, (16) represents the lithium nitride/lithium oxide collection chamber, (17) represents the water vapor inlet, (18) represents the lithium nitride/lithium oxide feed, (19) represents the water vapor outlet, and (20) represents the lithium hydroxide collection chamber.
The present disclosure proposes a new method and apparatus for extracting and preparing high-purity lithium hydroxide from low-purity lithium salts, which has low requirements for the purity of the materials, can efficiently separate magnesium and lithium, and only uses a small amount of chemical agents and has minimal impact on the environment. It can be used for the development and utilization of lithium resources, including salt lake brines.
The present disclosure proposes a new method and apparatus for extracting and preparing high-purity lithium hydroxide from low-purity lithium salts, which requires lower purity for materials, can efficiently separate magnesium and lithium, and has smaller chemical agent usage and ecological damages. The method utilizes the characteristic of high selective permeability of Li+ by lithium ion ceramic solid electrolyte, which can effectively prevent impurity ions from passing through, and realizes the production of high-purity lithium hydroxide products from low-purity lithium salt materials through reasonable electrode design. The reaction is carries out at a temperature of 150℃-450℃; the electrolysis voltage is between 1.5V-3V, and the current density is 1-100mA/cm2. The lithium ion ceramic solid electrolyte includes but is not limited to lithium lanthanum zirconate (LLZO) , tantalum-doped lithium lanthanum zirconate (LLZTO) , niobium-doped lithium lanthanum zirconate
(LLZNO) , and lithium aluminum titanium phosphate (LATP) . The mass fraction of lithium in low-purity lithium salts is between 0.1%-16%, where the low-purity lithium salts may include impurities such as potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl2) , and magnesium chloride (MgCl2) , among others.
The present disclosure provides a method for one-step preparation of lithium hydroxide. The method is based on the reduction of water vapor at a low potential, combined with the reaction of lithium ions to generate LiOH. The process directly produces LiOH using a lithium-containing molten salt as an electrolyte material at a temperature of 150℃-450℃, with an electrolysis voltage of 1.5V-3V and a current density of 1-100mA/cm2. A solid-state electrolyte is placed between the anode and the cathode of the electrolysis, and water vapor is directed to pass through the cathode in the electrolysis.
In some embodiments, during the electrolysis process, under the applied electric field, the sacrificial electrode plate at the electrolytic anode loses electrons to form metal cations that enter the molten salt system, and at the same time, lithium ions in the molten salt system move towards the solid electrolyte through which they can reach the electrolytic cathode. Water vapor is directed to pass through the cathode in the electrolysis, where H2O molecules are reduced to H2 on the inert electrode by gaining electrons, leaving OH-to combine with lithium ions to form high-purity LiOH.
In some embodiments, the reaction is carried out at a temperature of 200℃-400℃, or 250℃-350℃, or 280℃-300℃, with an electrolysis voltage of 1.8V-2.5V, or 2.0V-2.3V, and a current density of 10-900mA/cm2, or 30-800mA/cm2, or 50-550mA/cm2.
In some embodiments, the sacrificial electrode of the anode includes but is not limited to aluminum, zinc, and iron.
In some embodiments, the inert electrode at the cathode is a porous electrode, including but not limited to graphite, nickel, nickel-iron alloy, and platinum.
In some embodiments, the lithium-containing molten salt is a low-purity lithium salt, with impurities including but not limited to potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl2) , and magnesium chloride (MgCl2) .
In some embodiments, the mass fraction of lithium element in the low-purity lithium salt is 0.1%-16%.
The reaction equations are:
Overall reaction: Me + nLiCl + nH2O = MeCln + nLiOH + n/2H2, where Me represents metal;
Anode (sacrificial electrode) : Me-ne-= Men+;
Cathode: 2Li+ + 2H2O + 2e-= 2LiOH + H2;
The advantage of the disclosed one-step method for preparing lithium hydroxide is that it is simple and can obtain high-purity lithium hydroxide from low-concentration lithium-containing molten salts. The by-product is economically valuable hydrogen, and this method does not produce toxic or harmful waste to the environment.
The present disclosure also provides an electrolysis device for the one-step preparation of lithium hydroxide. The device includes an anode, a cathode, and a solid electrolyte using lithium-containing molten salt as an electrolyte material and performs electrolysis at a reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100mA/cm2. A solid electrolyte is placed between the anode and cathode, and water vapor is introduced at the cathode during electrolysis.
In some embodiments, the cathode is an inert porous electrode.
In some embodiments, the electrolytic device includes a lithium hydroxide collection chamber.
In some embodiments, the electrolysis device includes a water vapor inlet and a water vapor/hydrogen outlet.
Further, the electrolysis device includes sealing materials.
The present disclosure also provides a method for preparing lithium hydroxide using a two-step process. The method includes:
Step 1: N2 and O2 are reduced and combined with lithium ions to form Li3N or Li2O at low potentials use a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100mA/cm2. A solid electrolyte is placed between the anode and the cathode during electrolysis, and nitrogen or oxygen is directed to pass through the cathode during the reaction.
Step 2: React the generated Li3N or Li2O with water to generate lithium hydroxide monohydrate with a purity of 95.0%-99.99%
In some embodiments, in the first step, under the action of an external electric field, the sacrificial electrode plate at the anode of the electrolysis loses electrons to form metal cations that enter the molten salt system, while the lithium ions in the molten salt system move towards the solid-state electrolyte and pass through the solid-state electrolyte to reach the electrolysis cathode.
In some embodiments, in the first step, under the action of the external electric field, the sacrificial electrode plate at the anode of the electrolysis loses electrons to form metal
cations that enter the raw material molten salt system, while lithium ions in the molten salt system move towards the solid electrolyte and reach the electrolysis cathode through the solid electrolyte. In the electrolysis cathode, nitrogen or purified air (excluding CO2, SOx and NOx, etc. ) is introduced, and N2 and O2 molecules obtain electrons on the inert electrode of the electrolysis cathode and combine with lithium ions to form Li3N and Li2O.
In some embodiments, in the second step, the generated Li3N or Li2O is collected and transferred to the hydrolysis chamber. Water vapor is introduced into the hydrolysis chamber, and Li3N and Li2O spontaneously are hydrolyzed to produce high-purity monohydrate lithium hydroxide with a purity of 95.0%-99.99%.
In some embodiments, the temperature of the electrolysis reaction is at 200℃-400℃, or 250℃-350℃, or 280℃-300℃, the electrolysis voltage is at 1.8V-2.5V, or 2.0V-2.3V, and the current density is at 10-900mA/cm2, or 30-800mA/cm2, or 50-550mA/cm2.
In some embodiments, the sacrificial anode of the anode includes but is not limited to aluminum, zinc, and iron, and the inert electrode of the cathode includes but is not limited to graphite, nickel, nickel-iron alloy, and platinum.
In some embodiments, the lithium-containing molten salt in the present invention is low-purity lithium salt, with impurities including but not limited to potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl2) , magnesium chloride (MgCl2) , etc.
In some embodiments, the mass fraction of lithium element in the low-purity lithium salt is 0.1%-16%.
In some embodiments, the preparation of monohydrate lithium hydroxide leads to the production of lithium hydroxide.
The reaction equations are:
overall reaction: Me + nLiCl + n/6N2 + nH2O = MeCln + nLiOH + n/3NH3 (where Me represents metal)
or Me + nLiCl + n/4O2 + n/2H2O = MeCln + nLiOH
Anode (sacrificial electrode) : Me-ne-= Men+
The cathode: 6Li+ + N2 + 6e-= 2Li3N or 4Li+ + O2 + 4e-= 2Li2O.
Hydrolysis: Li3N + 3H2O = 3LiOH + NH3 and/or Li2O +H2O = 2LiOH.
The present disclosure provides an electrolytic device for producing lithium hydroxide by a two-step method. The device includes an anode, a cathode, a solid-state electrolyte, and a hydrolysis chamber. The electrolyte material is a molten salt containing lithium, and the first step of the electrolytic reaction is operated at a temperature of 150℃-450℃, a voltage of 1.5V-3V, and a current density of 1-100mA/cm2. A solid-state electrolyte
is set between the anode and the cathode during electrolysis, and nitrogen or oxygen is introduced at the cathode. In the hydrolysis chamber, Li3N and Li2O undergo a second-step hydrolysis reaction.
In some embodiments, the cathode is an inert porous electrode.
In some embodiments, the electrolysis device comprises a nitrogen/oxygen (purified air inlet) inlet and a nitrogen/oxygen (purified air inlet) outlet.
In some embodiments, the electrolytic cell includes a lithium hydroxide collection chamber.
In some embodiments, the electrolysis device includes sealing materials.
In some embodiments, the hydrolysis chamber comprises a water vapor inlet.
In some embodiments, the water decomposition chamber includes a water vapor or ammonia outlet.
The advantage of the two-step method for producing lithium hydroxide is that the process conditions are mild and safe, and high-purity lithium hydroxide can be extracted from low-concentration lithium-containing molten salt. The by-product, ammonia, also has certain economic value, and generates no toxic or harmful waste.
Example 1
FIG. 3 shows an example electrolysis apparatus, in which LLZTO lithium-ion ceramic electrolyte tube or LLZTO tube 22 is employed as the ceramic electrolyte, and an aluminum rod is employed as the sacrificial electrode 25. The electrolyte material or the molten lithium salt 26 used in this example is LiCl-AlCl3-NaCl-KCl-MgCl2 (molar ratio of 51.7: 43.1: 1.7: 1.7: 1.8) molten salt. The electrolysis reaction is carried out at a temperature of 250℃ and with an electrolysis current of 50mA. The lithium ions in the anode chamber are driven by an external power through the LLZTO ceramic electrolyte tube or LLZTO tube 22 to enter the lithium hydroxide collection chamber 29, where they react with high-temperature water vapor entering through the water vapor inlet 24 in the stainless steel foam 23, producing LiOH according to the following formula: 2Li+ + 3H2O + 2e-= 2LiOH·H2O + H2, and generating a hydrate of lithium hydroxide and hydrogen, where the hydrate of lithium hydroxide remains in the lithium hydroxide collection chamber 29, which is collected as a product with a purity of 98.9%. The generated hydrogen and excess water vapor are discharged through the water vapor/hydrogen outlet 28 as by-products.
Example 2
FIG. 4 shows another example electrolysis apparatus. LLZTO lithium-ion ceramic electrolyte sheet (Φ22*4mm) is used as the ceramic electrolyte or LLZTO 33, and aluminum sheet is used as the sacrificial electrode 32. The electrolyte material is a molten lithium salt 31 consisting of LiCl-AlCl3-CaCl2-KCl-MgCl2 (molar ratio 39.6: 39.6: 2.0: 6.5: 12.3) . The reacting temperature is 250℃, and the electrolysis current is 50mA. The lithium ions in the anode compartment enter the lithium hydroxide collection chamber 37 through the LLZTO ceramic electrolyte sheet or LLZTO 33 under the drive of an external power supply. In the nickel or stainless foam 34, lithium ions react fully with the high-temperature water vapor introduced through the water vapor inlet 35 to generate LiOH·H2O and hydrogen according to:2Li+ + 3H2O + 2e-= 2LiOH·H2O + H2. The one-hydrate lithium hydroxide is collected in the lithium hydroxide collection chamber 37, with a purity of 98.2%. The generated hydrogen and excess water vapor are discharged through the water vapor/hydrogen outlet 36 as by-products.
Example 3
This is a description of a setup for a two-step electrolysis process, as shown in FIGs. 5A and 5B. The left side (FIG. 5A) of the setup is an electrolysis cell where the first step of electrolysis takes place. The ceramic electrolyte used is an LLZTO lithium-ion ceramic electrolyte tube 39, and the sacrificial electrode 42 is an aluminum rod . The electrolyte materials consist of a molten lithium salt 43, a mixture of LiCl-AlCl3-NaCl-CaCl2-MgCl2 (molar ratio of 20.8: 37.9: 10.4: 8.5: 22.4) . The reacting temperature of the electrolysis cell is 250℃, and the electrolysis current is 50mA. Lithium ions in the anode chamber are driven by an external power source through the LLZTO ceramic electrolyte tube 39 and enter the cathode chamber 46 of the electrolysis cell. In the stainless steel foam 40, the lithium ions react with oxygen in the nitrogen or purified air that is introduced through the nitrogen/purified air inlet 41. The reaction produces either 2Li3N or 2Li2O from 6Li++ N2 +6e-=2Li3N or 4Li++O2+4e-=2Li2O, respectively. The intermediate products, Li3N and Li2O, are collected in the electrolysis cell cathode chamber or lithium nitride/lithium oxide collection chamber 46. Excess nitrogen or purified air is discharged through the electrolysis cell outlet or the nitrogen/purified air outlet 45. The collected lithium nitride or lithium oxide is transferred to the water decomposition tank on the right side of the setup (as shown in FIG. 5B) through the feed inlet or the lithium nitride/lithium oxide feed 48. Water vapor enters the decomposition tank through the water vapor inlet 47 and reacts with the Li3N and Li2O added through the lithium nitride/lithium oxide feed 48 to produce either Li3N + 4H2O =
3LiOH·H2O + NH3 or Li2O + 2H2O = 2LiOH·H2O. The resulting monohydrated lithium hydroxide is collected as a product in the lithium hydroxide collection chamber 50 of the decomposition tank and has a purity of 99.0%. Excess water vapor and generated ammonia are discharged through the water vapor/ammonia outlet 49 as by-products.
Example 4
This is a description of another setup for a two-step electrolysis process, as shown in FIGs. 6A and 6B. LLZTO lithium ion ceramic electrolyte sheet or LLZTO 54 (Φ22*4mm) is used as the ceramic electrolyte, and the aluminum sheet or the sacrificial electrode 53 is used as the sacrificial anode. The electrolyte materials are LiCl-AlCl3-NaCl-KCl-MgCl2 (molar ratio 40.2: 38.1: 7.9: 5.8: 8.0) molten lithium salt 52. The electrolysis cell reacts at a temperature of 300℃ and with an electrolysis current of 100mA. In the anode compartment, lithium ions enter the lithium nitride/lithium oxide collection chamber 58 through the LLZTO ceramic electrolyte sheet or the LLZTO 54 under the drive of an external power source. The lithium ions fully react with oxygen in nitrogen or purified air introduced through the inlet 56 in the stainless steel foam 55 to form the reaction products according to: 6Li+ + N2 + 6e-=2Li3N or 4Li+ + O2 + 4e-= 2Li2O. The intermediate products Li3N and Li2O are collected in the electrolysis cell cathode compartment or the lithium nitride/lithium oxide collection chamber 58, and excess nitrogen or purified air is charged through the electrolysis cell outlet or the nitrogen/purified air outlet 57. The collected lithium nitride or lithium oxide is transferred to the right-side hydrolysis tank in FIG. 6B through the hydrolysis tank inlet or the lithium nitride/lithium oxide feed 60. The water vapor introduced through the hydrolysis tank inlet or the water vapor inlet 59 reacts with the Li3N and Li2O added through the inlet or the lithium nitride/lithium oxide feed 60 in the hydrolysis tank, producing the reaction products according to Li3N + 4H2O = 3LiOH·H2O + NH3 or Li2O + 2H2O = 2LiOH·H2O. The resulting monohydrate lithium hydroxide is collected in the lithium hydroxide collection chamber 62 of the hydrolysis tank as the product, with a purity of 99.9%. Excess water vapor and generated ammonia are discharged through the water vapor/ammonia outlet 61 as by-products.
The electrolysis current and cell voltage of the two-step method for preparing lithium hydroxide electrolysis cell are shown in FIGs. 7A and 7B. As can be seen from the figures, at a current of 100mA, the electrolysis voltage reached 1.8V and remained stable, indicating the formation of lithium nitride at the cathode during electrolysis. After disassembling the device, a noticeable purple-red solid was found on the cathode current collector, which is the solid
lithium nitride.
Claims (11)
- A method for preparing lithium hydroxide, comprising:reducing water vapor at a low potential in presence of lithium ions to generate LiOH by using a lithium-containing molten salt as an electrolyte material at an reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein a solid-state electrolyte is disposed between an anode and a cathode for electrolysis, and the water vapor is introduced at the cathode during the electrolysis.
- The method according to claim 1, wherein a sacrificial electrode of the anode comprises one or more of aluminum, zinc, and iron.
- The method according to claim 1, wherein an inert electrode of the cathode is a porous and comprises one or more of graphite, nickel, nickel-iron alloy, and platinum.
- The method according to claim 1, wherein the lithium-containing molten salt comprises impurities comprises one or more of potassium chloride (KCl) , sodium chloride (NaCl) , calcium chloride (CaCl2) , and magnesium chloride (MgCl2) .
- An electrolytic device for preparation of lithium hydroxide comprising: an anode, a cathode, and a solid electrolyte disposed between the anode and the cathode, wherein the electrolytic device is configured to use a lithium-containing molten salt as an electrolyte material and perform electrolysis at an reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein water vapor is introduced at the cathode during the electrolysis.
- A method for preparing lithium hydroxide, comprising:reducing N2 or O2 in presence of lithium ions to form Li3N or Li2O by using a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein a solid electrolyte is placed between an anode and a cathode for electrolysis, and nitrogen or oxygen is directed to pass through the cathode in the electrolysis; andreacting Li3N or Li2O with water to produce lithium hydroxide monohydrate with a purity of 95.0 wt%-99.99 wt%.
- The method according to claim 6, wherein reducing N2 or O2 in presence of lithium ions comprises directing N2 or O2 to pass through the cathode such that N2 or O2 receives electrons on an inert electrode of the cathode and the lithium ions combine with the reduced nitrogen or oxygen to form Li3N or Li2O.
- The method according to claim 6, wherein reacting Li3N or Li2O with water comprises collecting and transferring Li3N or Li2O to a hydrolysis chamber, into which water vapor is introduced, and Li3N or Li2O is hydrolyzed to form the lithium hydroxide monohydrate.
- The method according to claim 6, wherein a sacrificial electrode of the anode comprises one or more of aluminum, zinc, and iron.
- The method according to claim 6, wherein an inert electrode of the cathode comprises one or more of graphite, nickel, nickel-iron alloy, and platinum.
- An electrolysis device for preparing lithium hydroxide, comprising: an anode, a cathode, a solid electrolyte, and a hydrolysis chamber, wherein:the electrolysis device is configured to reduce N2 or O2 in presence of lithium ions to form Li3N or Li2O by using a lithium-containing molten salt as an electrolyte material at a reaction temperature of 150℃-450℃, an electrolysis voltage of 1.5V-3V, and a current density of 1-100 mA/cm2, wherein the solid electrolyte is placed between the anode and the cathode for electrolysis, and nitrogen or oxygen is directed to pass through the cathode in the electrolysis;wherein Li3N or Li2O is reacted with water in the hydrolysis chamber to produce lithium hydroxide monohydrate with a purity of 95.0 wt%-99.99 wt%.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211227355.5A CN117888123A (en) | 2022-10-09 | 2022-10-09 | Preparation method and device of high-purity lithium hydroxide based on lithium ion solid electrolyte |
| CN202211227355.5 | 2022-10-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2024078386A1 true WO2024078386A1 (en) | 2024-04-18 |
Family
ID=90651309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CN2023/123190 WO2024078386A1 (en) | 2022-10-09 | 2023-10-07 | A method and device for preparing high-purity lithium hydroxide based on lithium-ion solid-state electrolyte |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN117888123A (en) |
| WO (1) | WO2024078386A1 (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005033366A1 (en) * | 2003-10-08 | 2005-04-14 | Artem Valerievich Madatov | Method of producing hydrogen and device therefor |
| CN1653210A (en) * | 2002-03-15 | 2005-08-10 | 千年电池公司 | Hydrogen-assisted electrolysis processes |
| CN102409174A (en) * | 2010-09-23 | 2012-04-11 | 株式会社半导体能源研究所 | Method for recovering metallic lithium |
| CN202898560U (en) * | 2012-09-05 | 2013-04-24 | 中国东方电气集团有限公司 | Fused electrolysis device used for preparing metallic sodium |
| CN105540609A (en) * | 2015-12-30 | 2016-05-04 | 中国石油大学(北京) | Carbon-footprint-free ammonia synthesis device and method, and application thereof |
| CN107636204A (en) * | 2015-05-30 | 2018-01-26 | 清洁锂公司 | High-purity lithium and Related product and method |
| US20180029895A1 (en) * | 2016-08-01 | 2018-02-01 | The Board Of Trustees Of The Leland Stanford Junior University | Electro-thermochemical Li Cycling for NH3 Synthesis from N2 and H2O |
| CN109516437A (en) * | 2019-01-02 | 2019-03-26 | 广东石油化工学院 | A kind of method of electrochemical reduction-Thermochemical water decomposition cyle for hydrogen production |
| US20200399772A1 (en) * | 2019-06-21 | 2020-12-24 | Xerion Advanced Battery Corp. | Methods for extracting lithium from spodumene |
| CN112566867A (en) * | 2018-06-25 | 2021-03-26 | 西门子股份公司 | Process for producing ammonia capable of withstanding high currents |
| CN113811640A (en) * | 2018-12-28 | 2021-12-17 | 崔屹 | Electrolytic production of high purity lithium from low purity feedstock |
-
2022
- 2022-10-09 CN CN202211227355.5A patent/CN117888123A/en active Pending
-
2023
- 2023-10-07 WO PCT/CN2023/123190 patent/WO2024078386A1/en unknown
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1653210A (en) * | 2002-03-15 | 2005-08-10 | 千年电池公司 | Hydrogen-assisted electrolysis processes |
| WO2005033366A1 (en) * | 2003-10-08 | 2005-04-14 | Artem Valerievich Madatov | Method of producing hydrogen and device therefor |
| CN102409174A (en) * | 2010-09-23 | 2012-04-11 | 株式会社半导体能源研究所 | Method for recovering metallic lithium |
| CN202898560U (en) * | 2012-09-05 | 2013-04-24 | 中国东方电气集团有限公司 | Fused electrolysis device used for preparing metallic sodium |
| CN107636204A (en) * | 2015-05-30 | 2018-01-26 | 清洁锂公司 | High-purity lithium and Related product and method |
| CN105540609A (en) * | 2015-12-30 | 2016-05-04 | 中国石油大学(北京) | Carbon-footprint-free ammonia synthesis device and method, and application thereof |
| US20180029895A1 (en) * | 2016-08-01 | 2018-02-01 | The Board Of Trustees Of The Leland Stanford Junior University | Electro-thermochemical Li Cycling for NH3 Synthesis from N2 and H2O |
| CN112566867A (en) * | 2018-06-25 | 2021-03-26 | 西门子股份公司 | Process for producing ammonia capable of withstanding high currents |
| CN113811640A (en) * | 2018-12-28 | 2021-12-17 | 崔屹 | Electrolytic production of high purity lithium from low purity feedstock |
| CN109516437A (en) * | 2019-01-02 | 2019-03-26 | 广东石油化工学院 | A kind of method of electrochemical reduction-Thermochemical water decomposition cyle for hydrogen production |
| US20200399772A1 (en) * | 2019-06-21 | 2020-12-24 | Xerion Advanced Battery Corp. | Methods for extracting lithium from spodumene |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117888123A (en) | 2024-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2009238625B8 (en) | Method of making high purity lithium hydroxide and hydrochloric acid | |
| CN100455512C (en) | Method for preparing battery-stage monohydrate lithium hydroxide | |
| CN107653378A (en) | The recovery method of valuable metal in a kind of waste and old nickel cobalt manganese lithium ion battery | |
| CN110616438B (en) | Device and method for electrochemically preparing high-purity battery-grade lithium hydroxide | |
| KR101909724B1 (en) | Method of Preparing Lithium Hydroxide, and Method of Preparing Lithium Carbonate | |
| CN109772169A (en) | A kind of bipolar membrane electrodialysis system and its method for preparing lithium hydroxide | |
| CN102560535A (en) | Method for recovering lead in waste lead-acid storage battery filler by using wet process | |
| CN110745795B (en) | Method for synthesizing lithium bis (fluorosulfonyl) imide by using electrochemistry | |
| CN101713078A (en) | Device and method for preparing potassium ferrate through electrolysis | |
| JP2023103929A (en) | Method for recovering lithium from waste lithium ion battery | |
| CN101481096B (en) | Technological process for producing sulphuric acid from waste gypsum and carbon dioxide and implementing membrane coupled reactor thereof | |
| WO2024078386A1 (en) | A method and device for preparing high-purity lithium hydroxide based on lithium-ion solid-state electrolyte | |
| JP2023051697A (en) | Method for recovering lithium from waste lithium-ion battery | |
| Yang et al. | A study on the reaction of carbonation in the preparation of lithium carbonate powders | |
| CN101307470A (en) | Method for preparing additive agent electrolyte for electrolyzing aluminium from lithium-containing wastes | |
| WO2024016115A1 (en) | Co2 capture and desorption apparatus and method | |
| CN113151680A (en) | Method for recycling waste lithium batteries | |
| CN107128973B (en) | Method for preparing ammonium metavanadate from sodium vanadate | |
| CN218202985U (en) | Device for producing metal magnesium lithium by utilizing renewable energy sources | |
| CN209759047U (en) | Device for preparing lithium hydroxide by using high magnesium-lithium ratio old brine solution bipolar membrane electrodialysis method | |
| CN207567354U (en) | A kind of pilot-plant for being electrolysed soluble halogen | |
| CN116791105A (en) | Process for preparing lithium hydroxide by bipolar membrane electrolysis | |
| CN116654957A (en) | Method for preparing lithium carbonate by using electrolytic aluminum waste cathode carbon blocks | |
| CN117737455A (en) | Method for extracting lithium from electrolytic aluminum lithium-containing overhaul slag and lithium iron phosphate positive electrode waste in cooperation | |
| CN115522072A (en) | Device for producing metal magnesium lithium by utilizing renewable energy sources |