Method and apparatus for recycling lithium-ion batteries

Patent metadata

Field	Value
Publication number	US-2017077564-A1
Application number	US-201615358862-A
Country	US
Kind code	A1
Filing date	Nov 22, 2016
Priority date	Apr 4, 2012
Publication date	Mar 16, 2017
Grant date	—

Abstract

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

First claim

What is claimed is:

1 . A method for recycling lithium-ion batteries, comprising:
identifying a molar ratio for cathode materials for a new battery; forming a leach solution by combining crushed battery material from a lithium battery recycling stream with an acidic leach agent and hydrogen peroxide (H 2 O 2 ) to separate cathode materials from undissolved materials; filtering the undissolved materials from the formed leach solution to leave dissolved salts of cathode materials remaining in the leach solution; determining a composition of the leach solution by identifying a molar ratio of the cathode material salts dissolved therein; adding, based on the determined composition, Ni, Co, Mn or Al salts in a sulfate (xSO 4 ) or hydroxide (xOH) form to adjust the molar ratio of the dissolved cathode material salts in the leach solution to correspond to the identified molar ratio for the recycled battery, including adding a solution of aluminum sulfates and a chelating agent; and raising the pH of the leach solution to at least 10 for precipitating and filtering metal ions of the cathode materials to form a charge material precursor by coprecipitating the Ni, Co, Mn and Al salts remaining in the leach solution as a combined hydroxide (OH) 2 or carbonate (CO 3 ) having a molar ratio corresponding to the identified molar ratio for the recycled battery, the charge precursor material responsive to sintering for forming active cathode materials in an oxide form following sintering with lithium carbonate (Li 2 CO 3 ).

2 . The method of claim 1 further comprising, prior to adjusting the molar ratio, precipitating impurities from the leach solution by adding sodium hydroxide until the pH is in a range between 5.0-7.0 for precipitating hydroxide forms of the impurities outside the determined material parameters.

3 . The method of claim 1 further comprising raising the pH to a range of 10-13.0 for precipitating hydroxide precursor material.

4 . The method of claim 3 further comprising raising pH by adding sodium hydroxide to increase the pH to 11.0.

5 . The method of claim 1 wherein the cathode material salts include Ni, Mn and Co in a hydroxide form with different ratios.

6 . The method of claim 1 wherein the cathode material salts include Ni, Co and Al in a hydroxide form with different ratios.

7 . The method of claim 1 wherein acidic leach agent is a concentration of sulfuric acid is in the range of 2-5 M (molar).

8 . The method of claim 7 wherein the acidic leach agent is 4M sulfuric acid.

9 . The method of claim 1 wherein the charge material precursor has the form Ni x Mn y Co z (OH) 2 , NixMnyCozCO3, NixCoyAlz(OH)2 or NixCoyAlzCO3 where the molar ratios defined by x, y, and z are based on the determined material parameters of the new battery.

10 . The method of claim 6 further comprising, prior to adding charge material salts for adjusting the molar ratio, removing manganese ions from the leach solution.

11 . An apparatus for recycling exhausted lithium ion batteries, comprising:
a containment for extracting cathode material by leaching crushed spent battery materials to separate undissolved material in a solution; a filter for removing impurities by precipitating hydroxides and filtering after adjusting a pH of the solution to a range between 5-7; the containment responsive to removing manganese (Mn) ions from the solution, and addition of at least one of Ni, Co and aluminum salts based on a desired composition of resulting recovered charge materials, an inert atmosphere for precipitating the recovered precursor materials using at least one of sodium hydroxide or potassium hydroxide; and a heat source for sintering the recovered charge materials with lithium carbonate to form active cathode material.

12 . The apparatus of claim 11 wherein the containment includes:
added Ni or Co prior to precipitating the recovered charge materials; and
deferred addition of aluminum hydroxide until after precipitation and before sintering.

13 . The apparatus of claim 11 wherein the active charge material formed includes LiNixCoxAlzO2 where x, y and z defining the molar ratio of the resulting active charge material.

14 . The apparatus of claim 11 wherein the aluminum salts include at least one of adding aluminum sulfate Al 2 (SO 4 ) 3 or aluminum hydroxide (Al(OH) 3 ), the containment having a pH above 7 prior to adding the aluminum salts.

15 . A method of recycling batteries comprising:
generating a solution of aggregate battery materials from spent cells; precipitating impurities from the generated solution; maintaining a temperature of the solution sufficiently low to maintain a structure of the cathode material compounds in the generated solution; adjusting the solution to achieve a predetermined ratio of dissolved desirable materials, the desirable materials defining useful cathode materials; and precipitating the desirable material in the predetermined ratio to form cathode material for a new battery having the predetermined ratio of the desirable materials.

16 . The method of claim 15 further comprising
introducing lithium carbonate; and
sintering to form cathode materials in the form of LiNi x Co y Al z O 2 .

17 . The method of claim 15 further comprising introducing the lithium carbonate after precipitating the desirable materials and before sintering.

18 . The method of claim 15 wherein adjusting the desirable materials includes the addition of at least one of Ni, Co or Al.

19 . The method of claim 15 wherein the desirable materials remain in the predetermined ratio during precipitation.

20 . The method of claim 15 wherein adjusting the solution includes:
identifying a desired ratio of the desirable materials for use in recycled cathode material resulting from the generated solution;
adding raw materials to achieve the desired ratio, the raw materials including additional quantities of the desirable materials; and
adjusting a pH of the solution such that the desirable materials precipitate.

21 . The method of claim 15 wherein adding the raw materials includes adding additional quantities of the raw materials for achieving the desired ratio without separating the individual materials already in solution form.

22 . The method of claim 15 wherein the desirable materials include manganese (Mn), cobalt (Co), and nickel (Ni) extracted from cathode material of battery cells, the desirable materials remaining during precipitation, the desirable materials having the form Ni x Mn y Co z (OH) 2 or Ni x Mn y Co z CO 3 .

23 . The method of claim 15 wherein the desirable materials include aluminum (Al), cobalt (Co), and nickel (Ni) extracted from cathode material of battery cells, the desirable materials remaining during precipitation, the desirable materials having the form Ni x Co y Al z (OH) 2 or Ni x Co y Al z CO 3 .

24 . The method of claim 1 wherein the added chelating agent for NCA is 5-sulfosalicylic acid added to a distilled water solution including the aluminum sulfates.

25 . The method of claim 24 further comprising adding the aluminum sulfate solution with the chelating agent to the leach solution previously formed from the Ni and Co salts to a reactor for coprecipitation, the reactor having ammonium water and sodium hydroxide.

26 . The method of claim 1 wherein the concentration of the chelating agent is 0.05M

Assignees

• Worcester Polytech Inst

Inventors

• Wang Yan
• Gratz Eric
• Sa Qina
• Zheng Zhangfeng
• Heelan Joseph

Classifications

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• C22B7/006

  Wet processes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• Y02W30/84

  Recycling of batteries or fuel cells · CPC title

• C22B3/02

  Apparatus therefor · CPC title