US4917973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Secondary battery
Assignee: Sharp Corp
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Filing: 1989-07-18
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Granted: 1990-04-17
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Expires: 2009-07-18
Abstract
Abstract There is disclosed a secondary battery wherein either one of positive electrode and negative electrode elements is made of an active material, the color of which is changed according to a voltage between these electrodes and wherein= a window is formed for observing the color change of the electrode. Further, an electrochromic display device is disclosed in which a working electrode is made of a pyrolytic carbonaceous material which is obtained by thermal decomposition of a hydrocarbon compound at a low temperature of about 1,000° C.
Inventors
- 👤 Yoshikazu Yoshimoto
- 👤 Hiroshi Wada
- 👤 Tomonari Suzuki
- 👤 Masaru Yoshida
- 👤 Shigeo Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:32
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/48; H01M10/488; G; G02; G02F; G02F1/00; G02F1/01; G02F1/15; G02F1/153; G02F1/1533; H01M10/05; H01M4/00; H01M4/02; H01M4/36; H01M4/58; H01M4/583; H01M4/587; H01M4/86; H01M4/96; H01M6/00; H01M6/50; H01M6/5044; H01M6/505; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
143 words
A secondary battery which is composed of a positive electrode element, a negative electrode element, a separator containing an electrolyte therein which is inserted between the positive electrode element and the negative electrode element and a casing for packaging these elements therein, being characterized in that: either one of the positive and negative electrode is made of a pyrolytic carbonaceous material which is obtained by thermal decomposition of a hydrocarbon compound selected from benzene, propane and their derivatives at a low temperature of about 1,000° C., said pyrolytic carbonaceous material changing in the color thereof due to a change in stage structure of a graphite intercalation compound formed between adjacent layers which is caused in response to a voltage generated between the positive and negative electrodes; wherein the casing has a transparent window for observing the color change of said pyrolytic carbonaceous material.
Claim 2
Dependent Claim
143 words
A secondary battery which is composed of a positive electrode element, a negative electrode element, a separator containing an electrolyte therein which is inserted between the positive electrode element and the negative electrode element and a casing for packaging these elements therein, being characterized in that: either one of the positive and negative electrode is made of a pyrolytic carbonaceous material which is obtained by thermal decomposition of a hydrocarbon compound selected from benzene, propane and their derivatives at a low temperature of about 1,000° C., said pyrolytic carbonaceous material changing in the color thereof due to a change in stage structure of a graphite intercalation compound formed between adjacent layers which is caused in response to a voltage generated between the positive and negative electrodes; wherein the casing has a transparent window for observing the color change of said pyrolytic carbonaceous material.
Claim 3
Dependent Claim
81 words
An electrochromic display device which utilizes a change in color due to a change in the stage structure of a graphite intercalation compound as a working electrode being characterized in that the working electrode is comprised of a pyrolytic carbonaceous material which is obtained by thermal decomposition of a hydrocarbon compound selected from benzene, propane and their derivatives at a low temperature of about 1,000° C., said pyrolytic carbonaceous material having microcrystalline grains of a small radius of about 100 Å.
Claim 4
Dependent Claim
81 words
An electrochromic display device which utilizes a change in color due to a change in the stage structure of a graphite intercalation compound as a working electrode being characterized in that the working electrode is comprised of a pyrolytic carbonaceous material which is obtained by thermal decomposition of a hydrocarbon compound selected from benzene, propane and their derivatives at a low temperature of about 1,000° C., said pyrolytic carbonaceous material having microcrystalline grains of a small radius of about 100 Å.
References Cited (Backward Citations)
US3955879A
Cited
US4522901A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |