US4956247A
Expired / Lapsed
US
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Nonaqueous electrolyte secondary cell
Assignee: Bridgestone Corp
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Filing: 1989-03-29
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Granted: 1990-09-11
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Expires: 2009-03-29
Abstract
Abstract A secondary cell comprising a metal oxide positive electrode, a lithium negative electrode, and a nonaqueous electrolyte containing lithium ions exhibits a high capacity and a long cycle life when the positive electrode has a limited capacity per unit area.
Inventors
- 👤 Tadaaki Miyazaki
- 👤 Takao Ogino
- 👤 Takahiro Kawagoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:36
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/05; H01M10/052; H01M4/00; H01M4/02; H01M4/13; H01M4/131; H01M10/056; H01M10/0564; H01M10/0566; H01M10/0569; H01M4/134; H01M4/36; H01M4/48; H01M4/485; H01M4/50; H01M4/505; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
62 words
A nonaqueous electrolyte secondary cell comprising: a positive electrode of a metal oxide capable of occluding and releasing lithium ions, a negative electrode containing at least 80 mol% of metallic lithium, and a nonaqueous electrolyte solution containing lithium ions, wherein the positive electrode has a capcity per unit area of up to 7 mAH/cm 2 , and a thickness of 50-250 microns.
Claim 2
Dependent Claim
62 words
A nonaqueous electrolyte secondary cell comprising: a positive electrode of a metal oxide capable of occluding and releasing lithium ions, a negative electrode containing at least 80 mol% of metallic lithium, and a nonaqueous electrolyte solution containing lithium ions, wherein the positive electrode has a capcity per unit area of up to 7 mAH/cm 2 , and a thickness of 50-250 microns.
Claim 3
Dependent Claim
19 words
The cell of claim 1 wherein the negative electrode has a thickness of about 40 to about 500 μm.
Claim 4
Dependent Claim
42 words
The cell of any one of claims 1 to 4 wherein the nonaqueous electrolyte solution consists essentially of an electrolyte selected from the group consisting of LiAsF 6 , LiPF 6 , and LiClO 4 and mixtures thereof, and a nonaqueous solvent.
Claim 5
Dependent Claim
31 words
The cell of claim 5 wherein the nonaqueous solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxyethane, dioxolan, and γ-butyrolactone and mixtures thereof.
Claim 6
Dependent Claim
25 words
The cell of claim 3 wherein the nonaqueous solvent is a mixture of ethylene carbonate, propylene carbonate, and upt o 20% by volume of benzene.
Claim 7
Dependent Claim
20 words
The cell of claim 1, wherein the positive electrode has a capcity per unit area of 0.5-5 mAH/cm 2 .
Claim 8
Dependent Claim
19 words
The cell of claim 1, wherein the positive electrode has a thickness of about 70 to about 150 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |