Patent US5961671A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5961671A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus and method of preparing electrochemical cells

Assignee: Valence Technology Inc
•
Filing: 1997-09-17
•
Granted: 1999-10-05
•
Expires: 2017-09-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method for removing plasticizers such dibutyl phthalate from the anode, cathode, and polymeric matrix components of electrochemical cell precursors using carbon dioxide in the supercritical state is provided. The method forms porous polymeric structures that enhances the mass transport of ions in the cell which results in improved electrochemical performance.

Inventors

  • 👤 Wade Guindy
  • 👤 Steven D. Cochran
  • 👤 Carl Richwine
  • 👤 George Adamson
  • 👤 Porter H. Mitchell

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 09:45
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/04; H01M4/0402; H01M4/0409; H01M10/00; H01M10/05; H01M10/058; H01M10/052; H01M10/056; H01M10/0564; H01M10/0565; H01M4/0404; H01M4/043; H01M4/0435; H01M4/62; H01M4/621; H01M4/622; H01M4/623; H01M50/00; H01M50/40; H01M50/409; H01M50/411; H01M50/414; H01M50/426; H01M10/0525; H01M6/00; H01M6/14; H01M6/18; H01M6/181; H01M6/188; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108; Y10T29/49115; Y10T29/53; Y10T29/5313; Y10T29/53135

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 259 words
A method of preparing an electrochemical cell comprising an anode, a cathode, and a polymeric layer interposed between the anode and cathode which comprises the steps of: (a) forming an anode composition comprising a carbon material, a first polymer, and a first plasticizer; (b) forming a cathode composition comprising a cathode active material, a second polymer, and a second plasticizer; (c) forming a polymeric matrix comprising a third polymer and third plasticizer that is interposed between the anode composition and cathode composition, wherein the polymeric matrix formed has a first surface that is attached to a surface of the cathode composition and a second surface that is attached to a surface of the anode composition; and (d) removing said first, second, and third plasticizers by extraction with a supercritical fluid comprising carbon dioxide to form an electrochemical cell precursor which comprises contacting said anode composition, cathode composition, and polymeric matrix to said supercritical fluid, wherein said supercritical fluid during said contacting is maintained for a sufficient length of time such that the supercritical fluid takes up at least a portion of said plasticizers, and wherein during said contact the temperature of the supercritical fluid is maintained between about 32° C. to 60° C. and the pressure of the supercritical fluid is maintained between about 1,100 psi to 4,000 psi and wherein step (d) substantially does not cause any detachment of the cathode composition from the first surface of the polymeric matrix and substantially does not cause detachment of the anode composition from the second surface of the polymeric matrix.
Claim 2
Independent Claim 259 words
A method of preparing an electrochemical cell comprising an anode, a cathode, and a polymeric layer interposed between the anode and cathode which comprises the steps of: (a) forming an anode composition comprising a carbon material, a first polymer, and a first plasticizer; (b) forming a cathode composition comprising a cathode active material, a second polymer, and a second plasticizer; (c) forming a polymeric matrix comprising a third polymer and third plasticizer that is interposed between the anode composition and cathode composition, wherein the polymeric matrix formed has a first surface that is attached to a surface of the cathode composition and a second surface that is attached to a surface of the anode composition; and (d) removing said first, second, and third plasticizers by extraction with a supercritical fluid comprising carbon dioxide to form an electrochemical cell precursor which comprises contacting said anode composition, cathode composition, and polymeric matrix to said supercritical fluid, wherein said supercritical fluid during said contacting is maintained for a sufficient length of time such that the supercritical fluid takes up at least a portion of said plasticizers, and wherein during said contact the temperature of the supercritical fluid is maintained between about 32° C. to 60° C. and the pressure of the supercritical fluid is maintained between about 1,100 psi to 4,000 psi and wherein step (d) substantially does not cause any detachment of the cathode composition from the first surface of the polymeric matrix and substantially does not cause detachment of the anode composition from the second surface of the polymeric matrix.
Claim 3
Dependent Claim 27 words
The method of claim 1 further comprising the step of introducing an electrolyte solution comprising an electrolyte solvent and salt into the electrochemical precursor, after step d.
Claim 4
Dependent Claim 27 words
The method of claim 1 wherein the temperature ranges from about 35° C. to 50° C. and the pressure ranges from about 1,600 psi to 3,000 psi.
Claim 5
Dependent Claim 27 words
The method of claim 1 wherein the temperature ranges from about 35° C. to 45° C. and the pressure ranges from about 1,800 psi to 2,600 psi.
Claim 6
Dependent Claim 15 words
The method of claim 1 wherein the first, second, and third plasticizers comprise dibutyl phthalate.
Claim 7
Dependent Claim 14 words
The method of claim 1 wherein the supercritical fluid consists essentially of carbon dioxide.
Claim 8
Dependent Claim 27 words
The method of claim 1 wherein the temperature ranges from about 35° C. to 50° C. and the pressure ranges from about 1,600 psi to 3,000 psi.
Claim 9
Dependent Claim 27 words
The method of claim 5 wherein the temperature ranges from about 35° C. to 45° C. and the pressure ranges from about 1,800 psi to 2,600 psi.
Claim 10
Dependent Claim 23 words
The method of claim 2 which further comprises the step of removing moisture from the electrochemical cell precursor before introducing the electrolyte solution.
Claim 11
Dependent Claim 20 words
The method of claim 5 wherein the first, second, and third polymers comprise a copolymer of polyvinylidene difluoride and hexafluoropropylene.
Claim 12
Dependent Claim 25 words
The method of claim 1 wherein step (d) further comprises removing said supercritical fluid loaded with said portion of plasticizer taken up during said contacting.
Claim 13
Independent Claim 342 words
A method of preparing an electrochemical cell comprising an anode, a cathode, and a polymeric layer positioned between the anode and cathode which comprises the steps of: (a) forming an anode composition comprising a carbon material, a first polymer, and a first plasticizer; (b) forming a cathode composition comprising a cathode active material, a second polymer, and a second plasticizer; (c) forming a polymeric matrix comprising a third polymer and a third plasticizer that is positioned between the anode composition and cathode composition wherein the polymeric matrix formed has a first surface that is attached to a surface of the cathode composition and a second surface that is attached to a surface of the anode composition; and (d) removing said first, second, and third plasticizers by extraction with a supercritical fluid to form an electrochemical cell precursor by a process comprising the steps of: (i) providing an apparatus that comprises: a sealable chamber defining a compartment adapted to receive an article containing a plasticizer; means for circulating a supercritical fluid into said compartment that comes into contact with said article; and means for separating supercritical fluid and plasticizer from a mixture of supercritical fluid and plasticizer; (ii) placing said anode composition, cathode composition, and polymeric matrix into said compartment and contacting the same with a supercritical fluid that comprises carbon dioxide, wherein said supercritical fluid during said contacting is maintained for a sufficient length of time such that the supercritical fluid takes up at least a portion of said plasticizers, and wherein during said contact the temperature of the supercritical fluid is maintained between about 32° C. to 60° C. and the pressure of the supercritical fluid is maintained between about 1,100 psi and 4,000 psi; and (iii) removing said supercritical fluid loaded with said portion of plasticizer taken up during said contacting wherein step (d) substantially does not cause any detachment of the cathode composition from the first surface of the polymeric matrix and substantially does not cause detachment of the anode composition from the second surface of the polymeric matrix.
Claim 14
Independent Claim 342 words
A method of preparing an electrochemical cell comprising an anode, a cathode, and a polymeric layer positioned between the anode and cathode which comprises the steps of: (a) forming an anode composition comprising a carbon material, a first polymer, and a first plasticizer; (b) forming a cathode composition comprising a cathode active material, a second polymer, and a second plasticizer; (c) forming a polymeric matrix comprising a third polymer and a third plasticizer that is positioned between the anode composition and cathode composition wherein the polymeric matrix formed has a first surface that is attached to a surface of the cathode composition and a second surface that is attached to a surface of the anode composition; and (d) removing said first, second, and third plasticizers by extraction with a supercritical fluid to form an electrochemical cell precursor by a process comprising the steps of: (i) providing an apparatus that comprises: a sealable chamber defining a compartment adapted to receive an article containing a plasticizer; means for circulating a supercritical fluid into said compartment that comes into contact with said article; and means for separating supercritical fluid and plasticizer from a mixture of supercritical fluid and plasticizer; (ii) placing said anode composition, cathode composition, and polymeric matrix into said compartment and contacting the same with a supercritical fluid that comprises carbon dioxide, wherein said supercritical fluid during said contacting is maintained for a sufficient length of time such that the supercritical fluid takes up at least a portion of said plasticizers, and wherein during said contact the temperature of the supercritical fluid is maintained between about 32° C. to 60° C. and the pressure of the supercritical fluid is maintained between about 1,100 psi and 4,000 psi; and (iii) removing said supercritical fluid loaded with said portion of plasticizer taken up during said contacting wherein step (d) substantially does not cause any detachment of the cathode composition from the first surface of the polymeric matrix and substantially does not cause detachment of the anode composition from the second surface of the polymeric matrix.
Claim 15
Dependent Claim 27 words
The method of claim 12 further comprising the step of introducing an electrolyte solution comprising an electrolyte solvent and salt into the electrochemical precursor after step (d).
Claim 16
Dependent Claim 27 words
The method of claim 12 wherein the temperature ranges from about 35° C. to 50° C. and the pressure ranges from about 1,600 psi to 3,000 psi.
Claim 17
Dependent Claim 27 words
The method of claim 12 wherein the temperature ranges from about 35° C. to 45° C. and the pressure ranges from about 1,800 psi to 2,600 psi.
Claim 18
Dependent Claim 15 words
The method of claim 12 wherein the first, second, and third plasticizers comprise dibutyl phthalate.
Claim 19
Dependent Claim 14 words
The method of claim 12 wherein the supercritical fluid consists essentially of carbon dioxide.
Claim 20
Dependent Claim 27 words
The method of claim 17 wherein the temperature ranges from about 35° C. to 50° C. and the pressure ranges from about 1,600 psi to 3,000 psi.
Claim 21
Dependent Claim 27 words
The method of claim 17 wherein the temperature ranges from about 35° C. to 45° C. and the pressure ranges from about 1,800 psi to 2,600 psi.
Claim 22
Dependent Claim 23 words
The method of claim 13 which further comprises the step of removing moisture from the electrochemical cell precursor before introducing the electrolyte solution.
Claim 23
Dependent Claim 20 words
The method of claim 17 wherein the first, second, and third polymers comprise a copolymer of polyvinylidene difluoride and hexafluoropropylene.
Claim 24
Dependent Claim 25 words
The method of claim 12 wherein step (d) further comprises removing said supercritical fluid loaded with said portion of plasticizer taken up during said contacting.
Claim 25
Dependent Claim 19 words
The method of claim 12 wherein step (ii) comprises circulating said supercritical fluid into and out of the compartment.
Claim 26
Dependent Claim 25 words
The method of claim 12 wherein step (iii) comprises separating supercritical fluid and plasticizer from a mixture of supercritical fluid and plasticizer exiting the compartment.
Claim 27
Dependent Claim 25 words
The method of claim 12 wherein step (iii) comprises separating supercritical fluid and plasticizer from a mixture of supercritical fluid and plasticizer exiting the compartment.
Claim 28
Dependent Claim 20 words
The method of claim 12 wherein the first, second, and third polymers comprise a copolymer of vinylidene difluoride and hexafluoropropylene.
Claim 29
Dependent Claim 26 words
The method of claim 12 wherein step (ii) comprises phase shifting said supercritical fluid between a supercritical state and a subcritical state or a liquid state.
Claim 30
Dependent Claim 26 words
The method of claim 20 wherein the step of removing the moisture comprises circulating gas into said compartment to remove moisture from said electrochemical cell precursor.
Claim 31
Dependent Claim 21 words
The method of claim 28 wherein the gas is selected from the group consisting of air, nitrogen, argon and carbon dioxide.
Claim 32
Dependent Claim 10 words
The method of claim 29 wherein said gas is heated.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-10-04 2003-04-05 2003-10-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-10-04 2007-04-05 2007-10-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-10-04 2011-04-05 2011-10-05 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag