Regenerated lithium-ion cathode materials having modified surfaces

1. A regenerated cathode active material for use in a lithium-ion battery, the regenerated cathode active material comprising:

a core material comprising lithium and a transition metal oxide, the core material having a surface, wherein the core material is a recycled cathode active material that has been re-lithiated; and

at least two different lithium-ion conducting species on the surface of the core material, the at least two different lithium-ion conducting species selected from AlF 3 , Li 3 PO 4 , and a lithium metal oxide.

2. The regenerated cathode active material of claim 1 , wherein the re-lithiated recycled cathode active material is one of LiCoO 2 , LiMn 2 O 4 , LiMnO 2 , LiNiO 2 , LiFePO 4 , LiNiCoMnO 2 , LiNiCoAlO 2 , and LiNi 0.5 Mn 1.5 O 4 .

3. The regenerated cathode active material of claim 1 , wherein the lithium-ion conducting species are AlF 3 and Li 3 PO 4 .

4. The regenerated cathode active material of claim 1 , wherein the lithium-ion conducting species are AlF 3 and the lithium metal oxide.

5. The regenerated cathode active material of claim 4 , wherein the lithium metal oxide is one of Li 4 SiO 4 , LiAlO 2 , Li 2 ZrO 3 , and Li 2 TiO 3 .

6. The regenerated cathode active material of claim 1 , wherein the at least two different lithium-ion conducting species form a coating on the core material.

7. The regenerated cathode active material of claim 1 , wherein the at least two different lithium-ion conducting species are non-uniformly positioned on the core material such that a portion of the surface of the core material is exposed.

8. The regenerated cathode active material of claim 7 , wherein the exposed portion of the core material has a coating comprising a lithium-ion conducting material.

9. The regenerated cathode active material of claim 1 , wherein the core material has a particle size ranging between 5.0 and 25.0 micron, inclusive, and the lithium-ion conducting species have a particle size ranging between 1.0 nm and 100 nm, inclusive.

10. A regenerated cathode active material for use in a lithium-ion battery, the regenerated cathode active material comprising:

a core material comprising a transition metal oxide and lithium, the core material having a surface; and

multiple lithium-ion conducting species on the surface, wherein the core material is a recycled cathode active material that has been re-lithiated.

11. A method of producing a regenerated cathode active material for a lithium ion battery, the method comprising:

using cathode active material removed from an end-of-life lithium-ion battery, recycled with a direct recycling process, and re-lithiated, the cathode active material comprised of a core material having a surface on which organic species and inorganic species exist, the inorganic species selected from LiOH, Li 2 CO 3 , Li 2 O and LiF,

rinse the cathode active material with a solvent to remove the organic species from the surface of the cathode active material;

after removing the organic species, either:

heat the cathode active material to a temperature of ≥700° C. and ≤1000° C. in a hydrogen atmosphere to convert LiOH to Li 2 O; and

react the cathode active material with carbon dioxide at a temperature of ≥400° C. and ≤700° C. to convert Li 2 O to Li 2 CO 3 , resulting in the cathode active material having Li 2 CO 3 and LiF as most or all remaining inorganic species, or:

remove LiOH and Li 2 O from the surface by dissolving in water, resulting in the cathode active material having Li 2 CO 3 and LiF as most or all remaining inorganic species; and

convert the Li 2 CO 3 and LiF to lithium-ion conducting species by reacting with one or more of aluminum, a metal oxide and a phosphate using a solid-state reaction.

12. The method of claim 11 , wherein converting Li 2 CO 3 and LiF to lithium-ion conducting species comprises reacting the LiF with aluminum to produce AlF 3 and reacting Li 2 CO 3 with a metal oxide to produce a lithium metal oxide.

13. The method of claim 12 , wherein the metal oxide is SiO 2 , Al 2 O 3 , ZrO 2 , or TiO 2 and the lithium metal oxide is Li 4 SiO 4 , LiAlO 2 , Li 2 ZrO 3 , or Li 2 TiO 3 , respectively.

14. The method of claim 11 , wherein converting Li 2 CO 3 and LiF to lithium-ion conducting species comprises reacting the LiF with AlPO 4 to produce AlF 3 and Li 3 PO 4 and reacting Li 2 CO 3 with a metal oxide to produce a lithium metal oxide.

15. The method of claim 14 , wherein the metal oxide is SiO 2 , Al 2 O 3 , ZrO 2 , or TiO 2 and the lithium metal oxide is Li 4 SiO 4 , LiAlO 2 , Li 2 ZrO 3 , or Li 2 TiO 3 , respectively.

16. The method of claim 11 , wherein converting Li 2 CO 3 and LiF to lithium-ion conducting species comprises reacting the LiF and the Li 2 CO 3 with AlPO 4 to produce AlF 3 and Li 3 PO 4 .

17. The method of claim 11 , wherein the cathode active material after re-lithiation is one of LiCoO 2 , LiMn 2 O 4 , LiMnO 2 , LiNiO 2 , LiFePO 4 , LiNiCoMnO 2 , LiNiCoAlO 2 , and LiNi 0.5 Mn 1.5 O 4 .

18. The method of claim 11 , wherein the solid-state reaction comprises:

select the one or more of aluminum, the metal oxide and the phosphate as the converting material;

form a mixture by mixing the converting material with the cathode active material, wherein an amount of the converting material is 1.0 wt % to 5.0 wt % of the cathode active material and has a diameter of between 1.0 nm and 100 nm, inclusive; and

calcine the mixture at a temperature of between ≥600° C. and ≤1100° C. for a period of time.

19. The method of claim 11 , wherein the lithium-ion conducting species form a coating on the core material.

20. The method of claim 11 , wherein, when removing LiOH and Li 2 O from the surface by dissolving in water, the surface from which the LiOH and Li 2 O are removed is exposed, the method further comprising:

coating exposed portions of the surface with a lithium-ion conducting material.