US 20050260465 A1
A cartridge for a fuel cell. In one aspect, the cartridge can have either fuel or water or cleaning solution. Multiple different cartridges can be used in a single electronic device. The cartridge can be pierced by a piercing device that can be electronically for mechanically operated. The piercing device allows water to be removed from the cartridge. A cover can be over the area which will be pierced by the piercing device.
1. A method, comprising:
using a first cartridge which stores an alcohol fuel in an electronic device that uses of direct methanol fuel cell; and
using a second cartridge in said electronic device, where said second cartridge includes a cleaning solution for the direct methanol fuel cell therein.
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8. A fuel supplying system for a direct methanol fuel cell, comprising:
a first part, which holds a cartridge for a direct methanol fuel cell, which cartridge includes a reservoir for alcohol solution therein, and which cartridge has at least one portion which can be pierced;
a tightening mechanism, which tightens around said cartridge; and
a piercing mechanism, which pierces said cartridge that said at least one portion, and locates a piercing part into said reservoir.
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15. A fuel cartridge, comprising;
a plurality of housing surfaces, adapted to hold a liquid alcohol containing fuel therein,
an opening surface, adapted to allow liquid to flow thereto responsive to placing said cartridge in a specified device which receives said cartridges; and
a covering part, which covers said opening surface, and can be removed to expose said opening surface.
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This application claims priority from Provisional Application No. 60/587,733, filed Jul. 13, 2004, and Provisional Application No. 60/572,549, filed May 18, 2004, the disclosures of which are herein incorporated by reference.
Direct methanol fuel cells have become extremely promising as a power source for use in portable electric and electronic appliances. The basic technology described in U.S. Pat. No. 5,599,638 describes the use of the direct methanol fuel cell, which generates power from methanol by removing protons directly from the methanol. This operates without using liquid acid or a reformer, and has many benefits including a biorenewable fuel source, and virtually no undesired pollutants as output.
One of the applications of such a fuel cell is for use in powering portable electronic equipment, such as laptop computers and cellular telephones and the like. When used in this way, it is predicted that the methanol would be supplied for the user in cartridges which could be inserted into the electronic device, and used to power the electronic device. When the cartridge is empty, the cartridge is replaced with a new cartridge, typically a cartridge which is readily available. In this way, the user can use the cartridges in place of batteries.
However, unlike disposable batteries, the cartridges produce relatively few pollutants. In addition, the expectation is that a cartridge of methanol will last many times longer than a battery of comparable size.
There are many issues involved in such a system, and the present application describes technological solutions to a number of these issues.
The present application describes a number of issues associated with use of a fuel cartridge and a portable electronic device.
One aspect describes determining an optimal amount of water to be used in a fuel cartridge with methanol therein.
Another aspect describes different canisters, one for water, and one for methanol fuel.
Another aspect describes configuring an electronic system which can be powered from either methanol or batteries, and sizing the methanol cartridge of a similar size to a battery.
Another aspect describes the ways of holding the fuel cell into the electronic device, and different ways of receiving fuel from the cartridge.
Another aspect, which is usable not only in fuel cells, but also in any branded device, relates to a way of detecting authenticity of the disposable device.
These and other aspects will now be described in detail with reference to the accompanying drawings, wherein:
A basic direct methanol fuel cell intended for use with an electronic device is shown in
The first side 109 of the proton electrolyte membrane is in contact with the aqueous methanol solution. The second side 111 of the proton electrolyte membrane is in contact with air, which is supplied through 112, either passively or using a fan or fluid pump 113.
More operations of the methanol fuel cell is carried out according to the known reaction. Water is produced as part of this reaction. In order to minimize the amount of spare water which is carried by the device, a water recovery unit 115 operates to recover water from the fuel cell, and return it to the aqueous solution container 106.
The water recovery system is intended to recover all of the water within the methanol system, as the used by the fuel cell. However, no system of this type can ever be perfect. The present inventor believes that some water will always be lost due to various circumstances. For example, the methanol fuel cell requires air to operate; some water will be lost during the production of the air. In addition, while it is desirable to use pure water in this system, there may be a buildup of contaminants over time, and it may be desirable to periodically intentionally remove a portion of the water from the fuel cell. Many of these different reasons may contribute to the desire to replenish a portion of the water at various times.
Previous systems, such as described in publication 2004-000938, have described that the fuel cartridges will maintain the highest possible concentration of methanol. According to a first aspect, described according to this embodiment, the system herein finds an amount of water to be replenished on a periodic basis. For example, it may be decided that during each fuel replenishment cycle, 10% of the water should be changed. In this embodiment, a certain amount of the water from the water recovery unit 115 is stored into a removal tank 120. This amount may be metered by a flow meter 119. In any case, a certain amount of the water is removed into the water removal tank 120. The water removal tank 120 may then use residual heat from the fuel cell to evaporate the water, or may allow the water to drip out in some other way. The tank 120 is preferably a removable and either cleanable or replaceable tank, since the contaminants that accumulate in the water may be part of that tank.
The methanol fuel which is stored in cartridge 100 is intentionally diluted with a specified amount of water based on the amount of water removed, and a calculated amount of water which will be lost by the fuel cell. This dilution is intended to replenish that amount lost through normal operation of the fuel cell, as well as the amount which is intentionally removed. In one embodiment, the amount which is intentionally removed can be zero, and in that embodiment, the fuel is intentionally diluted by substantially exactly the amount which makes up for the amount of loss of water within the fuel cell.
It is contemplated that the amount of water lost during operation of the fuel cell is probably 0.1-2% of the total water quantity at any given time. It may be desirable to change a comparable amount of the water during each fuel cell cycle. For example, if the fuel cell is 98% efficient in recycling the water, then may be desirable to intentionally remove another 2% of the water to avoid contaminant buildup. In one embodiment, therefore, an amount of water is intentionally removed that is within 10% of the amount of the water which is unintentionally lost to fuel cell operation. However, the amount of water which is removed can be any amount, ranging from zero in an embodiment where no water is removed, to as high as five times the amount of water unintentionally removed. In another embodiment, as much as 10% of the total amount of water in the fuel cell may be changed. However, is contemplated that the amount intentionally removed remain between 1 and 2% during each cycle of operation of the fuel cell.
In another embodiment, the auxiliary cartridge 210 may be a water cartridge, used to replenish and/or change the water used in the reservoir at 106. It may be desirable to periodically change the water, in which case a water cartridge 210 could be used. The water in the cartridge 210 may be of special characteristics, for example it may be extremely filtered, or have a high concentration of certain kinds of ions which may be used to clean the methanol device. In this embodiment, the reservoir 106 is maintained at the bottom of the cellular phone, and an adjustable drain 215 is also provided. The drain is normally closed, but may be electronically or mechanically opened to allow all of the water and/or water fuel mixture to be removed from the reservoir.
In the embodiment, each of the cartridges includes a special indicia shown as 220 which indicates the contents of the cartridge. The indicia may be of a specified shape, detected by the unit. For example, the indicia 220 indicates that the cartridge is a fuel cartridge, while the indicia 221 indicates that the cartridge is a water cartridge.
Periodically the user may need to add more water or remove water. When the fuel cell detects a water cartridge, it may prompt the user to open the drain to allow a certain amount of the water to be drained out, thereafter replenishing the water from the water cartridge 221.
In an alternative embodiment, a special cleaning cartridge, may be used. The fuel cell uses specified kinds of catalysts, such as platinum catalysts, which may over time become less effective due to impurities in the water or fuel or other. The special cleaning cartridge may be of a special kind of solvent which is intended for use in cleaning the direct methanol fuel cell. The cleaning cartridge may cause the fuel cell to undergo a cleaning operation, and again after which the residue is removed through drain 215.
In this embodiment, the cartridges are shown as generally cylindrical, although they may be of any shape. In this embodiment, the cartridges are clipped into place, and held by spring clips 232. The spring clips 232 are shown inside the view in
In the embodiment of
In an alternative embodiment, the clip positions are electronically controlled by a solenoid. In this embodiment, shown in
According to another aspect of this system, the fuel canisters are formed in the size of conventional batteries. For example, in the embodiment shown in
It is contemplated that canisters the size of different batteries would have numerous advantages. First of all, packaging for battery-sized fuel canisters could use the same packaging conventionally already available for batteries. This system contemplates batteries of AAA, AA, C or D size, as well as battery packs formed of packed together battery cells. For example, two or three battery cells are often held together, and shrink-wrapped, as shown in
This embodiment may use conventional valves or the like to allow the fuel from the fuel canister to the imported into the fuel cell. An alternative, however, uses a puncturing mechanism. In the
The user may signal their desire to remove a canister by pressing a special button, such as 415. This causes the clips to retract, allowing the user to remove the canister from the area 421. The user then presses another canister into place. A mechanical switch 422 contacts the canister that has been pressed into place, and causes the clips to be moved towards one another. The motor monitors an amount of torque placed on the clips. When an amount of torque exceeds a specified amount, for example 8 ft.-pounds, the clips are stopped and locked into place.
An important feature when using these fuel cells will be branding of the fuel which is used. Low quality or substandard fuel may cause eventual problems with the fuel cell, or may be more diluted and not work as well within the fuel cell. The users may want to rely on the branding of the fuel that is used.
However, counterfeit copying of consumable devices is rampant. This environment is usable not only with a fuel cell of this type, but also with any device which can be easily counterfeited. Examples of such devices include most consumables; e.g., cartridges for printers and laser printers are quite often counterfeited as have many other similar consumables. Accordingly, while this embodiment describes use in a fuel cell, for determining whether the fuel cell cartridge is counterfeit, it may alternatively be used in other similar systems, and more specifically, in any consumable item.
The counterfeit prevention indicator uses a one-way code. One-way codes are well known in the art. Basically, a one-way code takes advantage of large numbers to produce a code which is difficult for another to produce, but easy for someone to verify as being real. Public-key encryption is one example of one-way codes. When using a public-key encryption system, a code is produced which is easy to verify as being correct, but very difficult to duplicate. Any such code of this type can be used. The code can be a hash function, or any other kind of cryptographic verification code.
The code 805 may be a machine-readable number, or may be a two-dimensional or one-dimensional bar code, or may be encrypted in a hologram, or encoded on the device using any other known means. Techniques of encoding a number into a hologram are well known. In an embodiment, a reader is also provided which may be a relatively inexpensive device offer to users for a nominal fee. The reader reads and decrypts the code, and determines authenticity and validity. The reader can also be included into other devices, such as handhelds, PDAs, or other kinds of computers.
The reader may be given to users, or alternatively may be provided to the retail establishments to allow the retail establishments to determine and verify the authenticity of the device.
In a particularly preferred embodiment, the number is encoded on a hologram, and the reader includes a hologram reader, as well as a computer for detecting the one-way code. The one-way code detection may be done on a single chip, may be updated as necessary, and the like.
The cell phone 899 includes matching thread portions 910 which match with and thread to, the thread portions 902 on the cartridge 900. This allows the fuel canister 900 to be screwed into place and held tight against the connection surface 920 of the cell phone. When held tight in this way, the connection surface 904 of the canister 900 may be pressed tight against the connection surface 920 of the cell phone. In one embodiment, the connection surface 904 may include an O-ring shown as 905 which maintains a fluid tight connection.
The connection surface of the cell phone, 920, also includes a fuel receptacle piercing portion 930 thereon. The fuel receptacle portion may be simply a stationary piercing portion that pierces the surface 904 of the canister when the canister is screwed therein. In another embodiment, however, a motor 932 may electrically move the piercing portion 930 into the fuel canister once the fuel canister has been seated into place.
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The shrink wrap may be formed with perforations thereon to enable easier removal. A cross-section of the
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Another embodiment is shown in
In an embodiment, the structural portion 1425 of the receiving portion 1410 may be mostly hollow and filled with supporting ribs 1417 that establish pressure but allows elastic deformation so that the inner diameter 1412 can be expanded somewhat to allow the fuel canister to be placed therein. Once secured in place, any of the piercing mechanisms described above with respect to
The receiving mechanism 1410 may be hinged using hinge mechanism 1409 to allow the receiving mechanism to be pointed at an angle relative to the surface of the electronic device. This may facilitate inserting the fuel canister 1400.
Although only a few embodiments have been disclosed in detail above, other modifications are possible. All such modifications are intended to be encompassed within the following claims.