Patent Application
20080311474
The present invention relates to a method of manufacturing a battery. More specifically, the invention relates to a method of manufacturing a standardized cylindrical zinc-air battery. Furthermore, the invention relates to a method of manufacturing a button cell battery having a variety of shapes in addition to the circular shape.
Scaling down of electrical devices has long been attempted and thus many portable electronics have been developed. In recent years, however, as a new paradigm, called ubiquitous Internet, has been introduced, a small size and easy-carrying electronic devices have been being developed in a further extensive and intensive way. Most electronic devices such as MP3 players, digital cameras, mobile telephones, PDAs, laptop computers or the like are being developed into a compact and easily portable form. In addition to this miniaturization, an attempt has also been made to provide a variety of functions to a single device such as an MP3 phone, and a camera phone. While these attempts provide to users a freedom of movement and convenience of use, a stable supply of power should be associated therewith and currently draws attentions as a technical challenge to be solved.
Conventionally, a battery has extensively been used as a power supplying means to electrical devices. Conventional batteries include a primary battery such as a manganese batter, an alkaline manganese battery and a zinc-air battery, and a secondary battery such as a Ni—Cd battery, a Ni—H battery, a lithium ion battery. Among them, the zinc-air battery has advantages of providing a relatively high voltage of 1.4V, and having a higher density of energy and a larger discharging capacity. Furthermore, since it exhibits a nearly constant discharging characteristic until being exhausted, the zinc-air battery is considered an alternative for the mercury battery, of which use is restricted because it contains heavy metals.
The above zinc-air battery includes, in general, a cathode, an anode, a separator for isolating them, and an electrolyte. These elements are sealed by a cathode can and an anode can, both of which are made of a conductive material. The cathode can and anode can are contacted with the cathode and anode respectively to serves as a cathode terminal and an anode terminal respectively. In particular, in order to prevent leakage of the electrolyte from inside of a battery, the cathode can and anode can need to be sealed. Conventionally, a gasket is inserted between the cathode can and anode can, which are then crimped for hermetically sealing.
These conventional button cell batteries are disclosed in U.S. Pat. No. 5,423,027, U.S. Pat. No. 5,486,431 issued to Tuttle, et al., Korean Patent No. 3060321, and the like. The conventional technology will be explained in detail, with reference to the accompanying drawings.
The button cell battery of
As shown in
As described above, in the conventional battery manufacturing process, a can is crimped to seal the battery, so that the process can be simplified. When the cathode can 20 is crimped, however, a pressure is exerted on the central portion of the cathode can 20, which is to be contacted with the cathode 14, thereby causing a deformation. In the case where the crimping pressure is increased in order to improve the precision of sealing, the above problem becomes worse. In addition, the gasket 26 interposed between the cathode can 20 and the anode can 22 leads to a further complicated manufacturing process.
In addition, in case of manufacturing a circular button cell battery, the conventional crimping method is suitable, while in case where a polygonal-shaped battery such as a rectangular or pentagonal one is preferred, the crimping is overlapped at the corners of a polygon and thus the crimping method is not applicable to the manufacturing of polygonal batteries.
Referring to
The membrane is a permeable membrane containing water molecules and generates hydroxyl ions (OH−) by contacting oxygen in air. This reaction may be expressed by the following chemical equation.
O2+2H2O+4e−4OH− Chemistry FIG. 1
In the above reaction, electrons are supplied through the cathode can 20. The membrane is commonly made of carbon, but may be formed of other suitable materials, depending on the required voltage or its applications.
In this way, since the cathode reaction needs oxygen, the cathode must be provided with a path capable of contacting air. Thus, the cathode can 20 is provided with an air hole 21 formed at its bottom. When a batter is not used, the air hole 21 is sealed to suppress the cathode reaction.
The hydroxyl ions generated through the above chemical reaction are transferred to the zinc gel, which is an anode, through the separator 16. The separator 16 is permeable for hydroxyl ions, and on the other hand functions to prevent leakage of the zinc gel and to provide insulation between the zinc gel and the membrane.
The zinc gel contains mainly zinc powder and is mixed with additives and an electrolyte. Commonly, the electrolyte employs an aqueous solution of potassium hydroxide (KOH). If hydroxyl ions are transferred inside of the zinc gel, the zinc powder reacts with the hydroxyl ions to be oxidized. This reaction can be expressed by the following chemical equation.
Zn+2OH−Zn(OH2+2e−
Zn+2OH−ZnO+H2O+2e− Chemistry FIG. 2
Due to this reaction, electrons are generated from the anode and the electrons are transferred through the anode can 22. Through this chemical reaction, theoretically a voltage of 1.65V can be derived at maximum.
The conventional zinc-air batteries are mostly implemented as a button cell type. In the button cell type zinc-air battery, similarly, hermetical sealing of the battery is performed through crimping of can. A conventional method of manufacturing a zinc-air battery is disclosed in Japanese Patent Laid-open Publication No. 2002-373711.
Referring to
At the can distal area, a gasket 26 is interposed between the anode can 22 and the cathode can 20, and the cathode can 20 and the gasket 26 are crimped towards the anode can 22 to thereby seal the battery.
Such zinc-air batteries have favorable properties in terms of energy density, and discharging capacity and characteristic. But use of the conventional zinc-air battery has been limited to special areas such as hearing aids, cameras or the like. In particular, such zinc-air batteries have been commercialized as a button type battery only, but have not been manufactured in cylindrical standard types such as AAA, AA and the like. In order to commercialize a cylindrical zinc-air battery, they must be manufactured so as to generate a voltage and current suitable to the applications of the cylindrical batteries. Also, a manufacturing process must be developed so as to allow the zinc-air batteries to be made in a cylindrical form.
Referring to
Therefore, in order to fabricate a cylindrical zinc-air battery, there needs to provide a method of bonding the separator 12 and the cathode membrane 14 while preventing the zinc gel from being leaked.
Accordingly, the present invention has been made in order to solve the above problems, and it is an object of the invention to provide a method of manufacturing a button cell battery, in which a separate gasket is not necessitated to be interposed between an anode can and a cathode can and deformation of cans by crimping can be avoided.
Another object of the invention is to provide a method of manufacturing a button cell battery, which is applicable to a polygonal button cell battery in addition to a circular button cell battery.
A further object of the invention is to provide a method of manufacturing a zinc-air battery, which can be applied to a polygonal button cell battery while preventing deformation of a can.
A further object of the invention is to provide a cylindrical zinc-air battery and a method of manufacturing the same, in which leakage of zinc-gel is blocked.
In order to accomplish the above objects of the invention, according to one aspect of the invention, there is provided a battery comprising: an anode; a cathode; an anode can disposed to enable electrons to transfer against the anode; a cathode can disposed to enable electrons to transfer against the cathode; and a body forming a battery body, wherein one end of the body is fusion-bonded with an end portion of the anode can and the other end of the body is fusion-bonded to an end portion of the cathode can, thereby hermetically sealing the battery.
According to another aspect of the invention, there is provided a zinc-air battery comprising: a cathode membrane serving as a cathode; a zinc gel serving as an anode; a cathode can disposed to enable electrons to transfer against the cathode membrane; an anode can disposed to enable electrons to transfer against the zinc gel; and a body forming a battery body, wherein one end of the body is fusion-bonded with an end portion of the anode can and the other end of the body is fusion-bonded to an end portion of the cathode can, thereby hermetically sealing the battery.
According to a further aspect of the invention, there is provided a zinc-air battery including a zinc gel serving as an anode and a cathode membrane serving as a cathode and capturing the zinc gel, wherein both end portions of the cathode membrane face each other with a gap in-between, and the gap is filled with a resin.
According to another aspect of the invention, there is provided a zinc-air battery including a zinc gel serving as an anode and a cathode membrane serving as a cathode and capturing the zinc gel, wherein both end portions of the cathode membrane are overlapped and fusion-bonded.
According to another aspect of the invention, there is provided a cylindrical zinc-air battery comprising: a zinc gel serving as an anode; a cathode membrane serving as a cathode and capturing and hermetically sealing the zinc gel in a cylindrical form; a housing capturing the cathode membrane in a cylindrical form and having an opening formed therein for allowing air to pass through; and an insulator interposed between the cathode membrane and the housing and having an opening formed therein for allowing air to pass through.
According to another aspect of the invention, there is provided a method of manufacturing a battery, the battery including a first electrode, a second electrode, a first can disposed so as to allow electrons to transfer against the first electrode, a second can disposed so as to allow electrons to transfer against the second electrode, and a body constituting the battery body, the method comprising: a first fusion-bonding step in which an end portion of the first can is fusion-bonded with one end of the body; and a second fusion-bonding step in which an end portion of the second can is fusion-bonded with the other end of the body.
According to another aspect of the invention, there is provided a method of manufacturing a zinc-air battery, the zinc-air battery including a cathode membrane serving as a cathode, a zinc gel serving as an anode, a cathode can disposed so as to allow electrons to transfer against the cathode membrane, an anode can disposed so as to allow electrons to transfer against the zinc gel, and a body constituting the battery body, the method comprising: a first fusion-bonding step in which an end portion of the anode can is fusion-bonded with one end of the body; and a second fusion-bonding step in which an end portion of the cathode can is fusion-bonded with the other end of the body.
According to another aspect of the invention, there is provided a method of manufacturing a zinc-air battery, the zinc-air battery including a zinc gel serving as an anode and a cathode membrane serving as a cathode and capturing the zinc gel, the method comprising the steps of: disposing the cathode membrane such that both end portions thereof face each other with a gap in-between; and filling the gap with a resin and fusion-bonding the both end portions with the resin.
According to another aspect of the invention, there is provided a method of manufacturing a zinc-air battery, the zinc-air battery including a zinc gel serving as an anode, and a cathode membrane serving as a cathode and capturing the zinc gel, the method comprising the steps of: disposing the cathode membrane such that both end portions thereof are overlapped; and fusion-bonding the overlapped both end portions of the cathode membrane to each other.
According to another aspect of the invention, there is provided a method of manufacturing a cylindrical zinc-air battery, the zinc-air battery including a zinc gel serving as an anode and a cathode membrane serving as a cathode, the method comprising the steps of: hermetically sealing the cathode membrane in a cylindrical form; filling the zinc gel inside of the cathode membrane; inserting the filled cathode membrane into a cylindrical insulator; and forming a housing coating the insulator.
According to the invention, deformation of a can caused by can-crimping is prevented to improved reliability of contact between the can and an electrode (or MEA) and battery performance.
In addition, a cathode can and an anode can are not overlapped, thereby eliminating necessity of a separate gasket and thus simplifying the manufacturing process thereof.
Furthermore, the hermetical sealing of battery does not require can-crimping, thus enabling to fabricate various shapes of battery having a polygonal transversal cross-section, as well as a circular cross-section.
In particular, where the invention is applied to a zinc-air battery, the shape of the zinc-air battery can be diversified, departing from the conventional circular button cell type, thus broadening the application range of a zinc-air battery.
In addition, according to the invention, leakage of zinc gel can be prevented in a cylindrical zinc-air battery.
Furthermore, according to the invention, a cylindrical zinc-air battery not causing leakage of zinc gel can be fabricated, so that the zinc-air battery can be standardized to the universal AAA to A types.
Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The button cell battery of this embodiment includes a first can 52 and a second can 54 having a U-shape cross-section, and a body 56. Inserted inside of these are a first electrode 42 and a second electrode 44, a separator 46 for insulating them, and an electrolyte 48.
The first and second electrodes 42 and 44 are accommodated inside of the U-shape cans 52 and 54. The end portion 60 of the cans 52 and 54 is protruded higher than the electrodes 42 and 44. The first and second cans 52 and 54 are made of a conductive material and may be fabricated through a pressing process. The first electrode 42 is contacted with the first can 52 for electrons to be able to transfer and thus the first can 52 serves as an external terminal of the first electrode 42. Similarly, the second can 54 contacts the second electrode 44 to serve as an external terminal of the second electrode 44.
The separator 46 is made of a porous material to prevent the first and second electrodes 42 and 44 from being directly contacted with each other and at the same time allows electrons to be transferred through the electrolyte 48.
In this embodiment, hermetical sealing of the battery may be carried out by fusion-bonding of the cans 52 and 54 and the body 56. The body 56 is made of an insulation resin and insulates the first and second cans 52 and 54 from each other and also is fused at the end portion 60 of the cans 52 and 54 to seal the inside of the battery. The fusion-bonding of the body 56 and the cans 52 and 54 may be performed using ultrasonic, pressing, heating or the like, which will be hereafter described.
On the other hand, the shape of the end portion 60 of the cans 52 and 54 may be changed in order to improve reliability of the fusion-bonding.
As illustrated in
Hereafter, referring to
Then, at step 110, the second can 54 is fusion-bonded to one end of the body 56. Referring to
As illustrated in
Thereafter, the second can 54 is pressurized and the end portion of the can is inserted into the inside of the body 56 (step 110c). The body 56 is cooled and cured to fusion-bond the second can 54 and the body 56 (step 110d).
On the other hand, first, the second can 54 may be disposed at one end of the body 56, which is then heat-melted such that the end portion of the can 54 can be inserted into the body 56 by the weight of the can 54 and fusion-bonded thereto.
Alternatively, as shown in
As shown in
Referring to
As described above, in this embodiment, without crimping the cans 52 and 54, they are fusion-bonded with the body 56 to seal the battery, thereby enabling to prevent deformation of a can, which occurs at the central portion of the cans 52 and 54 when they are bent or crimped. Therefore, reliability of contact between the can 52, 54 and the electrode 42, 44 can be improved and the battery performance can be enhanced.
In addition, as long as the cans 52 and 54 have a U-shaped cross-section, they may be manufactured in the form of a polygon as well as a circular. Thus, the present invention can be applied to manufacturing of polygonal button cell batteries and thus applications of the battery can be extended into a variety of fields.
In the above embodiments, the second can 54 is fusion-bonded before the first can 52, but the first can 52 may be first fusion-bonded or the first and second cans 52 and 54 may be simultaneously fusion-bonded.
Referring to
Finally, at step 240, both ends of the body 56 are melted and, after the end portions of the cans 52 and 54 are inserted into the inside of the body 56, the body 56 is cooled and cured to fusion-bond the body 56 with the cans 52 and 54. The fusion-bonding at the step 240 may be performed in various ways, which are previously described in conjunction with
In this embodiment, two cans are fusion-bonded at the same time. Thus, the manufacturing process can be simplified to thereby improve the efficiency of battery production.
The present invention may be applied to the manufacturing of a zinc-air battery.
The zinc-air batter of this embodiment includes a cathode can 72 and an anode can 74 having U-shaped cross-sections, and a body 56. The cathode can 72 accommodates a membrane electrode assembly (MEA) 65, which is contacted with the cathode can 72. In addition, the inside of the battery is filled with a zinc gel 66 serving as an anode. The cathode can 72 and the anode can 74 are formed of a conductive material and can serve as a cathodic external terminal and an anodic external terminal respectively. On the other hand, the cathode can 72 is formed with a through-hole 68 such that the MEA 65 can be contacted with air.
In the zinc-air battery of this embodiment, the cathode can 72 and the anode can 74 are fusion-bonded to the body 56 to thereby seal the battery. The fusion-bonding of the body 56 with the cathode can 72 and the anode can 74 is carried out in the same way as in the previous embodiments of
Hereafter, a manufacturing method of a button cell zinc-air battery according to yet another embodiment of the invention will be explained, referring to
According to this embodiment, at step 300, an anode can 74 is fusion-bonded to one end of the body 56. The fusion-bonding of the anode can 74 and the body 56 may be carried out in various ways, which are previously explained in conjunction with
Thereafter, a zinc gel 66 is filled in the internal space formed by the assembly of the anode can 74 and the body 56 (step 310). The fusion-bonding of the body 56 and the anode can 74 seals the fusion area of them, thereby preventing leakage of the zinc gel 66.
At step 320, a cathode can 72 is fusion-bonded to the other end of the body 56. The cathode can 72 is pre-assembled with an MEA 65, or an anode membrane and a separator, and the end portion 60 of the cathode can 72 is protruded higher than the MEA 65. In this step, the end portion 60 of the protruded cathode can 72 is fusion-bonded to the other end of the body 56. The fusion-bonding of the cathode can 72 and the body 56 may be performed in various ways, which are previously explained in conjunction with
In this embodiment, the anode can 74 and the cathode can 72 are fusion-bonded with the body 56 in the described order, but the cathode can 72 may be first fusion-bonded. In addition, the anode can 74 and the cathode can 72 may be simultaneously fusion-bonded. In this case, similar to the previous embodiment described in conjunction with
In this embodiment, without crimping the cans 72 and 74, they are fusion-bonded with the body 56 to seal the battery, thereby enabling to prevent deformation of a can, which occurs when they are bent or crimped. Therefore, the battery performance can be improved. In addition, a polygonal can can be used to thereby enable to manufacture a polygonal button cell battery, as well as a circular one. Thus, application range for the zinc-are battery can be extended, beyond that of the circular button cell. In particular, besides a button cell battery, in case where the present invention is extensively applied to a standard battery type such as a cylindrical shape, a square pillar shape and the like, universal application of a zinc-air battery is possible.
Hereafter, a cylindrical zinc-air battery will be explained in greater detail.
The cylindrical zinc-air battery of this embodiment includes a zinc-gel 66, a separator 46 capturing the zinc gel 66, a membrane 64 serving as a cathode membrane. The membrane 64 may be enclosed with an insulator 78 and a housing 80.
The housing 80 may be a metallic plate fabricated through a press forming and protects the battery and holds the outer appearance. In addition, the housing 80 may be connected with the membrane 64 (which is a cathode) at the upper portion (not shown) of the battery and thus serve as a cathode can supplying electrons to the membrane 64. The insulator 78 is provided for insulating between the housing 80 and the membrane 64 to prevent current leakage. The insulator 78 may be fabricated by means of an injection molding process using a resin. On the other hand, an opening 84 is formed in the housing 80 and the insulator 78 for oxygen to be supplied to the membrane 64, which is a cathode.
The membrane 64 and the separator 46 may be fabricated in a plane form and then bent into a cylindrical form to enable to capture the zinc gel 66. Both end portions of the bent membrane 64 and the separator 46 face each other with a gap in-between, and are bonded with each other by means of a bonding member 82. The bonding member 82 is made of a resin and fusion-bonded to the membrane 64 and the separator 46, so that leakage of the zinc gel can be prevented at the bonding area of the both end portions. In addition, as illustrated, the bonding member 82 is formed in such a way to cover part of the membrane 64 and the separator 46, thereby further improving its sealing effect.
Hereafter, referring to
First, a cylindrical insulator 78 is prepared. The insulator 78 may be fabricated in the form of a cylinder using an injection molding process.
Then, a membrane 64 and a separator 46 having plane forms are prepared. As illustrated in
Thereafter, as illustrated in
A zinc gel 66 is filled inside of the above-formed cylindrical membrane 64 and the separator 46, which is then inserted inside of the insulator 78. Finally, a housing is formed so as to coat the insulator 78 to thereby complete the manufacturing of a cylindrical zinc-air batter.
Hereafter, referring to
In this embodiment, the same elements as in the previous embodiment are denoted by the same reference numerals and details thereon will not be repeated.
The cylindrical zinc-air battery of this embodiment includes a zinc gel, a separator capturing the zinc gel 66, and a membrane 64 serving as a cathode membrane. The membrane 64 may be wrapped around by an insulator 78 and a housing 80. In addition, an opening 84 may be formed in the housing 80 and the insulator 78 for air to come in and out.
The membrane 64 and the separator 46 may be formed in a plane form and then bent into the form of a cylinder so as to capture the zinc gel 66. At this time, both end portions of the bent membrane 64 and separator 46 are overlapped. In this case, as illustrated in
Then, referring to
Firstly, a cylindrical insulator 78 is prepared and a membrane 64 and a separator 46 having plane shapes are prepared. Then, as illustrated in
Thereafter, the overlapped both end portions 70 are fusion-bonded by means of heating, pressurizing or ultrasonic radiation through the jig 90. In this way, the both end portions of the membrane 64 and the separator 46 are fusion-bonded to each other to enable to seal the internal space thereof, and thus, in case where a zinc gel 66 is filled, leakage of the zinc gel 66 can be prevented.
A zinc gel 66 is filled inside of the above formed cylindrical membrane 64 and separator 46, which are then inserted into the inside of an insulator 78. Finally, a housing 80 is formed so as to coat the insulator 78 to complete manufacturing of a cylindrical zinc-air battery.
Although the present invention has been described with reference to several preferred embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and variations may occur to those skilled in the art, without departing from the scope of the invention as defined by the appended claims.
For example, in the batteries of the above embodiments, the separator 46 and the membrane 64 are illustrated as separate elements, but they may be embodied as a single element. In particular, according to the invention, these elements may be replaced by a membrane-electrode assembly (MEA). The MEA is a composite serving as a conventional cathode membrane and separator, which is well known in the art. Of course, instead of the MEA, a cathode membrane and a separator can be employed as separate elements, which is included in the scope of the invention as appreciated to those skilled in the art. In addition, each element of the invention may be made of one of well-known materials, from which those skilled in the art will be able to easily select the most suitable one.
In addition, in the manufacturing method of the above embodiments, individual process steps have been described in a particular order. However, it should be appreciated to those skilled in the art that these steps may be performed in a different order, without departing from the scope of the invention.
Furthermore, although in the embodiments of the invention, only essential elements related to the battery functions have been explained, in order to improve the functions of a battery, various well-known other elements may be added. For example, various functional membranes, such as a water-repellent membrane or a diffusion membrane, may be interposed between the membrane and the cathode can of a zinc-air battery.
Although the present invention has been described with reference to several preferred embodiments shown in figures, the description is just illustrative of the invention and various modifications and variations may occur to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2005-0044929 | May 2005 | KR | national |
| 10-2005-0044930 | May 2005 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2006/001946 | 5/24/2006 | WO | 00 | 7/9/2008 |
