Method for recycling lithium-ion battery

Patent metadata

Field	Value
Publication number	US-2020328482-A1
Application number	US-201716304166-A
Country	US
Kind code	A1
Filing date	Jun 12, 2017
Priority date	Jul 7, 2016
Publication date	Oct 15, 2020
Grant date	—

Abstract

Provided herein is a method for recycling lithium-ion batteries, comprising isolating a mixture of anode and cathode materials from waste lithium-ion batteries. The separated electrode materials can easily be collected with high recovery rate, providing a rapid, efficient and low-cost method for recycling electrode materials from waste lithium-ion batteries.

First claim

1 . A method for recycling lithium-ion batteries, comprising the steps of:
a) discharging the lithium-ion batteries; b) chopping the lithium-ion batteries into pieces to provide a mixture of a structural part, a first conductive metal part coated with a cathode layer, and a second conductive metal part coated with an anode layer; c) immersing the pieces of the chopped lithium-ion batteries into a polar solvent to form a heterogeneous mixture; d) processing the heterogeneous mixture with a high shearing mixer for a time period from about 5 minutes to about 5 hours to dissolve a binder material in the cathode and anode layers; e) screening the processed heterogeneous mixture to separate the structural part, first conductive metal part, and second conductive metal part from finer electrode materials comprising cathode and anode materials to provide a suspension comprised of the polar solvent and the finer electrode materials; and f) isolating the finer electrode materials in the suspension from the polar solvent; wherein the polar solvent is water, alcohol, ketone or a combination thereof; wherein the mixer comprises: (i) a mixing vessel having an upper part and lower conically tapering part; (ii) a screw arranged vertically at the centre of the mixing vessel, wherein the screw comprises a rotary shaft and a rotary blade spirally wound around the rotary shaft; and (iii) at least one rotary unit comprising a cylindrical rotary shaft coaxially arranged around the rotary shaft of the screw, a pair of rotary arms horizontally extending radially from the rotary shaft of the rotary unit, a supporting rod vertically extending from each of the rotary arms, and an agitator vane held by each of the supporting rods, wherein each of the agitator vanes comprises an upper portion bent forward relative to the rotation direction of the rotary unit, a middle portion attached to the supporting rod, and an lower portion inclined relative to the radial direction of the rotary unit and extending along the inner wall of the mixing vessel; wherein the screw rotates in a direction to urge the heterogeneous mixture upward and centrifugally, and the rotary unit rotates to urge the heterogeneous mixture downward and centripetally; and wherein the binder material in each of the cathode and anode layers is independently a water-based binder material, or a mixture of water-based and organic-based binder materials.

2 . The method of claim 1 , wherein the cathode material is lithium transition metal oxide selected from the group consisting of LiNiO 2 , LiNi x Mn y O 2 , LiNi x Co y O 2 , Li 1+z Ni x Mn y Co 1−x−y O 2 , LiNi x Co y Al z O 2 , LiCoO 2 , LiV 2 O 5 , LiTiS 2 , LiMoS 2 , LiMnO 2 , LiCrO 2 , LiMn 2 O 4 , LiFeO 2 , LiFePO 4 , and combinations thereof; wherein each x is independently from 0.3 to 0.8; each y is independently from 0.1 to 0.45; and each z is independently from 0 to 0.2.

3 . The method of claim 2 , wherein the lithium transition metal oxide is LiNi 0.8 Mn 0.2 O 2 , LiNi 0.6 Mn 0.4 O 2 , LiNi 0.8 Co 0.2 O 2 , LiNi 0.6 Co 0.4 O 2 , NMC532, NMC622, NMC811, NCA or a combination thereof.

4 . The method of claim 1 , wherein the pieces of the chopped lithium-ion batteries have an average length from about 0.5 inch to about 4.0 inches, or of about one quarter inch or less.

5 . The method of claim 1 , wherein each of the first and second conductive metal parts is independently selected from the group consisting of an aluminum thin plate, a copper thin plate, a gold thin plate, a silver thin plate, and a platinum thin plate.

6 . The method of claim 1 , wherein the polar solvent further comprises a salt selected from the group consisting of lithium carbonate, lithium bicarbonate, lithium phosphate, sodium carbonate, sodium bicarbonate, sodium phosphate, potassium carbonate, potassium bicarbonate, potassium phosphate, ammonium carbonate, ammonium bicarbonate, ammonium phosphate, and combinations thereof.

7 . The method of claim 6 , wherein the polar solvent has a pH from about 6 to about 8.

8 . The method of claim 1 , wherein the alcohol is selected from methanol, ethanol, isopropanol, n-propanol, t-butanol, or a combination thereof.

9 . The method of claim 1 , wherein a weight ratio of water to the alcohol is from about 5:95 to about 95:5.

10 . (canceled)

11 . (canceled)

12 . The method of claim 1 , wherein step d) is performed at room temperature.

13 . The method of claim 1 , wherein the heterogeneous mixture in step d) is heated at a temperature from about 35° C. to about 100° C., or from about 55° C. to about 75° C.

14 . The method of claim 1 , wherein the water-based binder material is selected from the group consisting of styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, nitrile butadiene rubber, acrylonitrile-styrene-butadiene copolymer, polybutadiene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyacrylonitrile, cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylcellulose, polyacrylic acid, polyacrylate, polymethacrylic acid, polymethacrylate, polyacrylamide, a salt of alginic acid, and combinations thereof

15 . The method of claim 1 , wherein the organic-based binder material is selected from the group consisting of polytetrafluoroethylene, perfluoroalkoxy polymer, polyvinylidene fluoride, copolymer of tetrafluoroethylene and hexafluoropropylene, fluorinated ethylene-propylene copolymer, terpolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, and combinations thereof.

16 . The method of claim 1 , wherein the finer electrode materials further comprise a conductive agent.

17 . The method of claim 1 , wherein the finer electrode materials are screened by passing through a sieve having a mesh width between 2 mm and 4 mm, or between 0.5 mm and 1.0 mm.

18 . The method of claim 1 , wherein isolation of the finer electrode materials is performed by filtration, decanting, settling, centrifugation, or a combination thereof.

19 . The method of claim 1 , wherein the recovery of finer electrode material is at least 90%, or at least 95%.

20 . The method of claim 1 , wherein the percentage of impurity in the recovered finer electrode material is less than 2%, less than 1%, less than 0.5%, less than 0.1%, or less than 0.05%.

21 . The method of claim 1 , wherein the mixer further comprises rectifier plates, wherein the rectifier plates are attached to the rotary unit and arranged between the screw and the agitator vanes.

22 . The method of claim 1 , wherein the screw of the mixer rotates at a speed from about 500 rpm to about 2,500 rpm and wherein the rotary unit of the mixer rotates at a speed from about 50 rpm to about 1,000 rpm.

Assignees

• Grst Int Ltd

Inventors

• Ho Kam Piu
• Wang Ranshi
• Shen Peihua

Classifications

• Y02W30/84

  Recycling of batteries or fuel cells · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M6/52

  Reclaiming serviceable parts of waste cells or batteries {, e.g. recycling} · CPC title

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title

• H01M4/623

  fluorinated polymers · CPC title