Chemistry: electrical current producing apparatus – product – and – With pressure equalizing means for liquid immersion operation
Reexamination Certificate
1999-05-27
2001-06-19
Chaney, Carol (Department: 1745)
Chemistry: electrical current producing apparatus, product, and
With pressure equalizing means for liquid immersion operation
C429S006000, C429S082000, C429S083000, C429S071000
Reexamination Certificate
active
06248464
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to batteries, and more particularly relates to an air-managing system for a metal-air battery.
DESCRIPTION OF THE RELATED ART
Metal-air battery cells include an air permeable cathode and a metallic anode separated by an aqueous electrolyte. During discharge of a metal-air battery, such as a zinc-air battery, oxygen from the ambient air is converted at the cathode to hydroxide, zinc is oxidized at the anode by the hydroxide, and water and electrons are released to provide electrical energy. Metal-air batteries have a relatively high energy density because the cathode utilizes oxygen from ambient air as a reactant in the electrochemical reaction rather than a heavier material such as a metal or metallic composition. Metal-air battery cells are often arranged in multiple cell packs within a common housing to provide a sufficient amount of power output. The result is a relatively lightweight battery.
To operate a metal-air battery cell, it is necessary therefore to provide a supply of oxygen to the air cathodes of the cells. An air manager system is typically used to provide reactive air and to isolate the air cathodes when the cell is idle. Some prior systems open air cathodes widely to the atmosphere or use a fan system to sweep a flow of new ambient air from openings across the air cathodes to supply oxygen at a rate sufficient to achieve the desired power output. The open air cathodes or the openings are generally sealed during non-use by sealing tapes, plugs, mechanical doors, etc. because the water vapor and oxygen in the ambient air would cause the cell to flood, dry out, or discharge in some circumstances, thereby leading to a reduction in cell efficiency and lifetime. Diffusion-controlling openings have been applied to the air manager, as shown in U.S. Pat. No. 5,691,074. However, a more strict isolation may sometimes be desired for a longer shelf life.
The above-described sealing systems such as a sealing-tape are generally designed for single use and require new sealing means such as a new tape to seal the opening again. Mechanical doors are usually durable and thereby can open and close the openings more than once. The doors typically are positioned on a battery housing case such that a disposable battery body may have door mechanisms, which may be reusable even after the battery loses its power. However, the mechanisms require expensive moving parts and they tend to leak.
Thus, there has been a need for a reusable and practical sealing system to prevent water vapor transfer and leakage current when the battery is not in use. The system should be simple and work repeatedly during a battery lifetime, and further minimize disposable parts to lower the cost and to protect the environment. Along these lines, it would be efficient not to have to dispose of an air manager when every cell pack reaches the end of its useful life. If the battery could be divided into a disposable part and a reusable part, a simple and reliable engaging means to connect two parts may be needed.
SUMMARY OF THE INVENTION
The invention seeks to provide an improved ventilation system and an improved ventilating method for a metal-air cell or battery, which has a long shelf life and retains essentially all its original power during a period of storage.
In accordance with the invention, this object is accomplished in a metal-air power supply system having two air pathway segments separated by a self-sealable septum, and a hollow needle to puncture the septum.
The present invention, therefore, provides a ventilation system for a metal-air battery having a housing or a case for enclosing at least one metal-air cell, at least one self-sealable septum, and one or more hollow needles. The case has at least one opening that is covered with the self-sealable septum and is sealed off from a reactive gas source or the outside air. Thus, the septum divides an air pathway into two segments. The first segment from an air cathode of the cell is enclosed in the case and terminated by the septum. The second segment to the outside air includes tubular passages of the hollow needles. When the needles penetrate the septum, the two segments are connected and the air pathway is completed to convey a reactive gas, e.g., oxygen, to the air cathode from the outside air.
The present invention provides a multi mode ventilation system for a metal-air battery with one or more openings connected to the outside air in the second segment. At least one air-moving device is disposed in the second segment such that the device may give a satisfactory air flow rate for required power. If the openings are preferably sized, leakage current of the cell may be lowered for non-use conditions when the air-moving device is off. Furthermore, the preferably sized openings prevent the cell from flooding and drying out by exchanging water vapor with the outside air. Thus, the lowest mode is for storage, a middle mode is for non-use, and the highest mode is to provide power with the air-moving device on.
The present invention further provides a power supply system having a cell pack with at least a self-sealable septum and an air-managing device with one or more hollow needles. The cell pack may be stored alone to maintain the original power. The air-managing device engages with the cell pack when the power supply is needed.
The present invention further provides an electric device with an air-managing device and a disposable cell pack with a self-sealable septum. The air-managing device is combined in the electric device such that the consumers may only have to buy a disposable cell pack.
The present invention further provides a cell pack including one or more metal-air cells in a housing which has air opening sealed by resealable septum.
The present invention further provides a reusable ventilation system that engages with an above-mentioned cell pack. The ventilation system has one or more hollow needles, at least one air moving device or fan, and one or more openings for air ingress and egress.
REFERENCES:
patent: 1299149 (1919-04-01), Duvall
patent: 2382675 (1945-08-01), Sutherland et al.
patent: 2745894 (1956-05-01), Nowotny
patent: 2880259 (1959-03-01), Nowotny
patent: 3865631 (1975-02-01), Clayman
patent: 3945846 (1976-03-01), Dey
patent: 4060670 (1977-11-01), Tamminen
patent: 4118544 (1978-10-01), Przybyla et al.
patent: 4189526 (1980-02-01), Cretzmeyer et al.
patent: 4360573 (1982-11-01), Rao et al.
patent: 4366213 (1982-12-01), Tamminen
patent: 4505996 (1985-03-01), Simonton
patent: 4525439 (1985-06-01), Simonton
patent: 4554226 (1985-11-01), Simonton
patent: 4649090 (1987-03-01), Oltman et al.
patent: 4816354 (1989-03-01), Tamminen
patent: 5069986 (1991-12-01), Dworkin et al.
patent: 5191274 (1993-03-01), Lloyd et al.
patent: 5356729 (1994-10-01), Pedicini
patent: 5362577 (1994-11-01), Pedicini
patent: 5486429 (1996-01-01), Thibault
patent: 5571630 (1996-11-01), Cheiky
patent: 5641588 (1997-06-01), Sieminski et al.
patent: 5691074 (1997-11-01), Pedicini
patent: 6068944 (2000-05-01), Witzigreuter
patent: 6087029 (2000-07-01), Golovin et al.
patent: 2 097 574 (1982-04-01), None
patent: WO 97/15090 (1997-04-01), None
Pedicini Christopher S.
Witzigreuter John D.
Alejandro R.
Alston & Bird LLP
Chaney Carol
LandOfFree
Air-managing system for metal-air battery using resealable... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Air-managing system for metal-air battery using resealable..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Air-managing system for metal-air battery using resealable... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2459259