US5695887A
Expired / Lapsed
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Chelation treatment for reduced self-discharge in Li-ion batteries
Assignee: Valence Technology Inc
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Filing: 1996-05-09
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Granted: 1997-12-09
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Expires: 2016-05-09
Abstract
Abstract The extent of self-discharge of rechargeable Li-ion secondary batteries is significantly reduced by treatment of LiMn 2 O 4 intercalation compound electrode material with a chelating agent, such as acetylacetone. This treatment decreases the incidence of non-coordinated Mn-ion sites which can lead to battery electrolyte decomposition and resulting loss of battery capacity. The treatment, which also includes annealing at about 400° C. to 800° C., further prevents such decomposition by varying the surface area and topography of the potentially catalytic electrode material.
Inventors
- 👤 Glenn G. Amatucci
- 👤 Alexandra Blyr
- 👤 Jean-Marie Tarascon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:35
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/13; H01M4/131; H01M10/00; H01M10/05; H01M10/052; H01M10/0525; H01M4/36; H01M4/48; H01M4/50; H01M4/505; H01M4/62; H01M4/621; H01M4/622; H01M4/623; H01M10/058; H01M4/133; H01M4/139; H01M4/1391; H01M50/00; H01M50/40; H01M50/409; H01M50/446; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108; Y10T29/49115
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
63 words
A rechargeable lithiated intercalation cell having reduced self-discharge, comprising a negative electrode, a nonaqueous electrolyte, and a positive electrode, wherein the positive electrode comprises a lithiated intercalation electrode, said lithiated intercalation electrode comprising a lithiated intercalation compound, said lithiated intercalation compound comprising an aggregate of particulates, the surfaces of said particulates having a passivating layer formed by chelating reaction with a chelating agent.
Claim 2
Dependent Claim
63 words
A rechargeable lithiated intercalation cell having reduced self-discharge, comprising a negative electrode, a nonaqueous electrolyte, and a positive electrode, wherein the positive electrode comprises a lithiated intercalation electrode, said lithiated intercalation electrode comprising a lithiated intercalation compound, said lithiated intercalation compound comprising an aggregate of particulates, the surfaces of said particulates having a passivating layer formed by chelating reaction with a chelating agent.
Claim 3
Dependent Claim
26 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 1, wherein said chelating agent comprises a bidentate, tridentate, quadridentate, pentadentate, hexadentate, or macrocyclic ligand.
Claim 4
Dependent Claim
32 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 2, wherein said bidentate ligand chelating agent comprises a dithiocarbamate, xanthate, carboxylate, tropolonate, ethylenediamine, 2,2'-bipyridine, 1,10-phenanthroline, o-phenylenebis(dimethylarsine), 1,2-bis(diphenylphosphine)ethane, β-diketonate, or salicylaldiminato.
Claim 5
Dependent Claim
27 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 2, wherein said tridentate ligand chelating agent comprises a terpyridene, acylhydrazone of salicylaldehyde, diethylenetriamine, or bis(3-dimethylarsinylpropyl)methylarsine.
Claim 6
Dependent Claim
72 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 2, wherein said quadridentate ligand chelating agent comprises a triethylenetetramine, β-diketonate Schiff base, or ligand of the type X(-Y) 3 , wherein X is N, P, or As, wherein Y is R 2 N, R 2 P, R 2 As, RS, or RSe, and wherein the connecting chain is (CH 2 ) 2 , (CH 2 ) 3 , or o-phenylene.
Claim 7
Dependent Claim
22 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 2, wherein said pentadentate ligand chelating agent comprises a mono-protonated ethylenediaminetetraacetate.
Claim 8
Dependent Claim
26 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 2, wherein said macrocyclic ligand chelating agent comprises a porphyrin, phthalocyanine, bis-dimethylglyoximato, or Schiff base.
Claim 9
Dependent Claim
34 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 1, wherein said lithiated intercalation electrode comprises Li x Mn 2 O 4 , where 0<x<2, and wherein said chelating agent comprises acetylacetone.
Claim 10
Dependent Claim
35 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 8, wherein said reaction comprises contacting said particulates with said chelating agent for a time ranging from about 1.5 hours to about 24 hours.
Claim 11
Dependent Claim
27 words
The rechargeable lithiated intercalation cell having reduced self-discharge according to claim 9, wherein said reaction further comprises annealing at a temperature in excess of about 400° C.
Claim 12
Dependent Claim
68 words
A rechargeable battery cell comprising a negative electrode, a positive electrode, and an intermediate non-aqueous electrolyte characterized in that said positive electrode comprises a particulate lithium intercalation compound the electrode surface particles of which are coated with a passivating layer of a composition comprising the carbonaceous by-products of annealing the ligand of a multidentate chelating agent which has been reacted to form a chelate with said intercalation compound.
Claim 13
Dependent Claim
68 words
A rechargeable battery cell comprising a negative electrode, a positive electrode, and an intermediate non-aqueous electrolyte characterized in that said positive electrode comprises a particulate lithium intercalation compound the electrode surface particles of which are coated with a passivating layer of a composition comprising the carbonaceous by-products of annealing the ligand of a multidentate chelating agent which has been reacted to form a chelate with said intercalation compound.
Claim 14
Dependent Claim
24 words
A rechargeable battery cell according to claim 11 characterized in that said chelating agent comprises a bidentate, tridentate, quadridentate, pentadentate, hexadentate, or macrocyclic ligand.
Claim 15
Dependent Claim
31 words
A rechargeable battery cell according to claim 11 characterized in that said lithiated intercalation electrode comprises Li x Mn 2 O 4 , where 0<x<2, and said chelating agent comprises acetylacetone.
Claim 16
Independent Claim
105 words
A method of making a rechargeable battery cell comprising a negative electrode, a positive electrode, and an intermediate non-aqueous electrolyte, which method comprises forming said positive electrode of a composition comprising a particulate lithium intercalation compound characterized in that a) said particulate lithium intercalation compound is intimately mixed with a multidentate ligand chelating agent to form a composition comprising a chelate of said intercalation compound with said ligand; and b) said chelate composition is annealed at a temperature in the range of about 400° C. to 800° C. to reduce said chelated ligand to carbonaceous by-products which coat the particulates of said lithium intercalation compound.
Claim 17
Independent Claim
105 words
A method of making a rechargeable battery cell comprising a negative electrode, a positive electrode, and an intermediate non-aqueous electrolyte, which method comprises forming said positive electrode of a composition comprising a particulate lithium intercalation compound characterized in that a) said particulate lithium intercalation compound is intimately mixed with a multidentate ligand chelating agent to form a composition comprising a chelate of said intercalation compound with said ligand; and b) said chelate composition is annealed at a temperature in the range of about 400° C. to 800° C. to reduce said chelated ligand to carbonaceous by-products which coat the particulates of said lithium intercalation compound.
Claim 18
Dependent Claim
27 words
A method according to claim 10 wherein said lithiated intercalation electrode comprises Li x Mn 2 O 4 , where 0<x<2, and said chelating agent comprises acetylacetone.
Claim 19
Dependent Claim
35 words
A method according to claim 15 wherein said lithium intercalation compound is mixed with said chelating agent for about 1.5 hours to about 8 hours and said chelate composition is annealed for about 24 hours.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2000-12-08 | 2001-06-09 | 2001-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-08 | 2005-06-09 | 2005-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-08 | 2009-06-09 | 2009-12-09 | $7700.00 | Window Closed / Lapsed |