US3847603A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a sintered iron negative plate for an alkaline storage battery
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1972-12-19
•
Granted: 1974-11-12
•
Expires: 1992-12-19
Abstract
Abstract Needle-shaped oxygen-containing iron compound particles are heated in a first temperature range in a hydrogen atmosphere to produce a loosely tied sintered body, pulverized into finely divided particles of a predetermined size, tamped into a mould to a desired density so that the constituting needle-shaped iron particles are intertwined. The tamped mould is sintered at a second temperature range higher than the first temperature range to provide a desired porosity. Alternatively, oxygen-containing needle-like iron compound particles are initially mixed with oxygen-containing spherical iron compound particles prior to the process described above. The end product prevents disintegration of active material and provides an increased ampere-hour capacity.
Inventors
- 👤 M Fukuda
- 👤 T Iwaki
- 👤 T Mitsumata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:02
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/02; H01M4/24; H01M4/26; H01M4/30; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A METHOD OF PREPARING AN IRON NEGATIVE PLATE FOR AN ALKALINE STORAGE BATTERY, COMPRISING THE STEPS OF: HEATING NEEDLE-SHAPED PARTICLES OF AN OXYGEN-CONTAINING IRON COMPOUND SELECTED FROM THE GROUPC CONSISTING OF IRON (III) OXYHYDROXIDE AND Y-TYPE FERRIC OXIDES AT A TEMPERATURE RANGE BETWEEN 700*C AND 850*C IN HYDROGEN ATMOSPHERE TO OBTAIN A SINTERED BODY; PULVERIZING SAID SINTERED BODY INTO FINELY DIVIDED PARTICLES; TAMPING SAID FINELY DIVIDED PARTICELS INTO A MOULD OF DESIRED SHAPE; AND SINTERING SAID TAMPED BODY AT A TEMPERATURE RANGE BETWEEN 700*C AND 1050*C IN HYDROGEN ATMOSPHERE.
Claim 2
Independent Claim
89 words
A METHOD OF PREPARING AN IRON NEGATIVE PLATE FOR AN ALKALINE STORAGE BATTERY, COMPRISING THE STEPS OF: HEATING NEEDLE-SHAPED PARTICLES OF AN OXYGEN-CONTAINING IRON COMPOUND SELECTED FROM THE GROUPC CONSISTING OF IRON (III) OXYHYDROXIDE AND Y-TYPE FERRIC OXIDES AT A TEMPERATURE RANGE BETWEEN 700*C AND 850*C IN HYDROGEN ATMOSPHERE TO OBTAIN A SINTERED BODY; PULVERIZING SAID SINTERED BODY INTO FINELY DIVIDED PARTICLES; TAMPING SAID FINELY DIVIDED PARTICELS INTO A MOULD OF DESIRED SHAPE; AND SINTERING SAID TAMPED BODY AT A TEMPERATURE RANGE BETWEEN 700*C AND 1050*C IN HYDROGEN ATMOSPHERE.
Claim 3
Dependent Claim
32 words
A method as claimed in claim 1 wherein said needle-shaped particles of an oxygen-containing iron compound are mixed with not more than 95 percent of spherical particles of Alpha -type ferric oxide.
Claim 4
Dependent Claim
27 words
A method as claimed in claim 1 wherein said needle-shaped particles of oxygen-containing iron compound are mixed with not more than 95 percent of spherical iron particles.
Claim 5
Dependent Claim
16 words
A method as claimed in claim 3 wherein said spherical iron particles are electrolytic iron particles.
Claim 6
Dependent Claim
16 words
A method as claimed in claim 3 wherein said spherical iron particles are carbonyl iron particles.
Claim 7
Dependent Claim
27 words
A method as claimed in claim 1 wherein said finely divided particles are mixed with not more than 95 percent finely divided spherical iron particles before tamping.
Claim 8
Dependent Claim
32 words
A method of preparing an iron negative plate as claimed in claim 1, wherein said needle-shaped particles of oxygen-containing iron compound is heated in the hydrogen atmosphere for at least 30 minutes.
Claim 9
Dependent Claim
24 words
A method of preparing an iron negative plate as claimed in claim 1, wherein said tamped body is sintered for at least 20 minutes.
Claim 10
Dependent Claim
30 words
A method of preparing an iron negative plate as claimed in claim 1, wherein said needle-shaped particles of oxygen-containing iron compound particles have a length-to-width ratio of at least 3/1.
Claim 11
Dependent Claim
26 words
A method of preparing an iron negative plate as claimed in claim 1, wherein said finely divided particles have a size smaller than about 32 mesh.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |