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EP-4740249-A2 - SEMI-DRY PREPARATION OF ELECTRODES, FLUORINE FREE ELECTRODES AND ENERGY STORAGE DEVICES PRODUCED THEREBY

EP4740249A2EP 4740249 A2EP4740249 A2EP 4740249A2EP-4740249-A2

Abstract

Disclosed herein is a semi-dry method of preparing an electrode slurry comprising a carbonaceous conductive material, an active material, a polymer binder, and a solvent wherein the electrode slurry has a fluorine content of less than about 900 parts per million. A battery cell comprising a cathode comprising a cathode current collector and a cathode active layer and an anode comprising an anode current collector and an anode active layer, wherein the active layers comprise high aspect ratio carbon elements and have a fluorine content of less than about 900 parts per mission. An energy storage device comprising a housing, a separator, and a cathode and an anode where the cathode and the anode comprise a current collector and an active layer where the active layer has a fluorine content of less than 900 parts per million.

Inventors

  • Cao, Wanjun Ben
  • CHEN, JI
  • Brambilla, Nicolo
  • JAO, DAVE
  • WANG, Luning

Assignees

  • Nanoramic, Inc.

Dates

Publication Date
20260513
Application Date
20240708

Claims (18)

  1. What is claimed is: 1. A semi dry method for preparing an electrode slurry comprising: mixing a carbonaceous conductive material, a solvent, an active material, and a polymer binder to form an electrode slurry, wherein the electrode slurry has a fluorine content of less than 900 parts per million.
  2. 2. The method of Claim 1, comprising the steps of: mixing a carbonaceous conductive material, a solvent to produce a first mixture; adding to the first mixture an active material to produce a second mixture; mixing the second mixture; adding to the second mixture a polymer binder to produce a third mixture; mixing the third mixture to form an electrode slurry, wherein the electrode slurry has a fluorine content of less than 900 parts per million.
  3. 3. The method of Claim 1, wherein the mixture of the carbonaceous conductive material, the plasticizer, the active material, and the polymer binder can be added in any order sequence to prepare the electrode slurry.
  4. 4. The method of Claim 1, wherein the solids content of the electrode slurry is greater than 80 weight percent the total weight of the electrode slurry.
  5. 5. The method of Claim 1, wherein a dispersant is mixed with the electrically conductive material and a solvent to produce the first mixture.
  6. 6. The method of Claim 1, wherein a plasticizer is mixed with the electrically conductive material and a solvent to produce the first mixture.
  7. 7. The method of Claim 1, wherein mixing is performed with a twin-screw extruder.
  8. 8. The method of Claim 1, wherein solvent is added to the second mixture, the third mixture, or both the second mixture and the third mixture.
  9. 9. The method of Claim 1, wherein the solvent is selected from water, alcohol, or mixtures thereof.
  10. 10. The method of Claim 1, wherein the active material is an anode active material, a cathode active material, or a combination thereof.
  11. 11. The method of Claim 1, wherein the solvent is also a plasticizer.
  12. 12. A battery cell comprising: a cathode that comprises a cathode current collector and a cathode active layer, wherein the cathode active layer comprises cathode active materials that include one or more of LFP, LiCoO2, LiNiO2, LiNiMnCoO2, LiNiO2, LiMn2O4, LiFePO4, and LiNixMnyCo1-x-yO2, NCMA, or a combination thereof, where x has a value 0.7 to 0.85 and where y is greater than 0.1; and wherein the cathode active layer contacts the cathode current collector; an anode that comprises an anode current collector and an anode active layer; where the anode active layer comprises an anode active material that includes graphite mixed with LixSiyOz, where x is 1 to 15, y is 1 to 4 and z is 1 to 9; the anode active layer contacts the anode current collector; wherein both the anode active layer and the cathode active layer each comprise high aspect ratio carbon elements; wherein the battery cell has a fluorine content of less than 900 parts per million.
  13. 13. An energy storage device comprising: a housing; a separator, a cathode and an anode disposed in the housing; where the anode and cathode are disposed on opposite sides of the separator; and where the cathode and the anode each comprises a current collector with an active layer disposed thereon; where the active layer comprises a carbonaceous conductive material, an active material, and a binder; wherein the active layer has a fluorine content of less than 900 parts per million.
  14. 14. The energy storage device of Claim 13, wherein the active layer includes an anode active layer and a cathode active layer; and wherein the cathode active layer, the anode active layer, or the cathode active layer and the anode active layer can undergo dimensional and/or geometric changes during operation of the storage device.
  15. 15. The energy storage device of Claim 13, wherein the current collector can undergo deformation in response to a change in the dimensions or geometry of the active layer.
  16. 16. The energy storage device of Claim 13, where the separator can undergo deformation to accommodate a change is dimensions or geometric shape of the active layers.
  17. 17. The energy storage device of Claim 13, where the active layer includes an anode active layer and a cathode active layer; wherein either the anode active layer or the cathode active layer comprise a first layer and a second layer, where the first layer contacts the current collector and where the second layer contacts the first layer; where the second layer has a smaller concentration of active materials than the first layer.
  18. 18. The energy storage device of Claim 17, where the second layer has a higher concentration of carbonaceous materials than the first layer.

Description

SEMI-DRY PREPARATION OF ELECTRODES, FLUORINE FREE ELECTRODES AND ENERGY STORAGE DEVICES PRODUCED THEREBY CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Application No.63/525,511, filed on July 7, 2023, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] This disclosure relates to a semi-dry preparation of electrodes and fluorine free electrodes produced thereby. The invention further relates to energy storage devices, particularly ultracapacitors and lithium ion batteries, using the fluorine free electrodes. In particular, the disclosure relates to the preparation of slurries for manufacturing fluorine free electrodes for energy storage devices. BACKGROUND OF THE INVENTION [0003] Lithium batteries are used in many products including medical devices, electric cars, airplanes, and consumer products such as laptop computers, cell phones, and cameras. Due to their high energy densities, high operating voltages, and low-self discharges, lithium ion batteries have overtaken the secondary battery market and continue to find new uses in products and developing industries. [0004] Generally, lithium ion batteries (“LIBs” or “LiBs”) comprise an anode, a cathode, and an electrolyte material such as an organic solvent comprising a lithium salt. More specifically, the anode and cathode (collectively, "electrodes") are formed by mixing either an anode active material or a cathode active material with a binder and a solvent to form a paste or slurry which is then coated and dried on a current collector, such as aluminum or copper, to form a film on the current collector. The anodes and cathodes are then layered or coiled prior to being housed in a pressurized casing containing an electrolyte material, which all together forms a lithium ion battery. [0005] Production of lithium ion batteries often relies on toxic and expensive components such as solvents and fluorinated polymers to provide the desired stability and performance for the finished energy storage devices. Recycling of toxic and/or expensive solvents during manufacturing increases costs and process complexity. Furthermore, fluorine-containing binders, such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), both are per- and polyfluoroalkyl substances known as PFAs, introduce toxic and potentially bioaccumulating decomposition products. [0006] A need remains for more environmentally friendly, less expensive, PFAs-free manufacturing of electrodes for energy storage devices. SUMMARY OF THE INVENTION [0007] Disclosed herein is a semi-dry method for preparing an electrode slurry comprising mixing a carbonaceous conductive material, a solvent, an active material, and a polymer binder to form an electrode slurry, wherein the electrode slurry has a fluorine content of less than 900 parts per million. [0008] Disclosed herein too is a battery cell comprising a cathode comprising a cathode current collector and a cathode active layer, wherein the cathode active layer include one or more of LFP, LiCoO2, LiNiO2, LiNiMnCoO2, LiNiO2, LiMn2O4, LiFePO4, and LiNixMnyCo1-x-yO2, NCMA, or a combination thereof, where x has a value 0.7 to 0.85 and where y is greater than 0.1; and wherein the cathode active layer contacts the cathode current collector; an anode that comprises an anode current collector and an anode active layer; where the anode active layer comprises an anode active material that includes graphite mixed with LixSiyOz, where x is 1 to 15, y is 1 to 4 and z is 1 to 9; the anode active layer contacts the anode current collector; wherein both the anode active layer and the cathode active layer each comprise high aspect ratio carbon elements; wherein the battery cell has a fluorine content of less than 900 parts per million. [0009] Disclosed herein too is an energy storage device comprising a housing; a separator a cathode and an anode disposed in the housing; where the anode and cathode are disposed on opposite sides of the separator; and where the cathode and the anode each comprises a current collector with an active layer disposed thereon; where the active layer comprises a carbonaceous conductive material, an active material, and a binder; wherein the active layer has a fluorine content of less than 900 parts per million. [0010] The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The following is a brief description of the drawings wherein like elements are numbered alike and which are presented for the purposes of illustrating the exemplary