JP4671652B2 - Battery case and battery - Google Patents

Description

  The present invention relates to a battery case and battery used for rechargeable batteries and the like, and more particularly to a thin battery case and battery used for small electronic devices such as mobile phones.

  In recent years, portable devices typified by mobile phones, portable computers, camera-integrated video tape recorders, etc. have been remarkably developed, and further miniaturization and weight reduction have been demanded. In addition, the demand for batteries as power sources for these portable devices continues to increase, and research on reducing the size and weight by increasing the energy density of the batteries is actively conducted. In particular, the lithium battery is a battery using lithium with a small atomic weight and a large ionization energy, so that it is possible to obtain a high energy density, to achieve a reduction in size and weight, and to be a battery that can be recharged more actively. It has been researched and has now been used for a wide range of applications including power supplies for portable devices.

  Batteries can be broadly divided into cylindrical and square types. The structure is that the positive and negative electrodes are housed in a metal battery case through a separator made of an insulating sheet, and an electrolyte is injected there. It is a sealed structure.

As a positive electrode of a lithium battery, for example, a metal oxide used as a positive electrode active material and a conductive material added thereto is generally used. Examples of the positive electrode active material include lithium cobaltate (LiCoO ₂ ) and lithium manganate (LiMn ₂ O ₄ ), and examples of the conductive material include acetylene black (AB) and graphite. As the negative electrode of the battery, a lithium titanium composite oxide such as lithium titanate (Li ₄ Ti ₅ O ₁₂ ) or an active material such as graphite or amorphous carbon solidified with a resin is used.

In the lithium battery, the charge / discharge voltage of the positive electrode active material made of LiCoO ₂ or LiMn ₂ O ₄ is about 4V, while the charge / discharge voltage of the negative electrode active material made of carbon material or the like is around 0V. Therefore, a high discharge voltage of about 3.5 V is achieved by combining these positive electrode active material, negative electrode active material, and electrolyte.

  For the positive electrode of the battery, the conductive material is added to the active material, and a binder such as polytetrafluoroethylene or polyvinylidene fluoride is added and mixed to form a slurry, which is formed into a sheet using a well-known doctor blade method. For example, the sheet is formed by cutting into a circular shape.

  Also, the negative electrode is added to the above active material, as in the positive electrode, a binder such as polytetrafluoroethylene or polyvinylidene fluoride, mixed to form a slurry, and this is formed into a sheet using a known doctor blade method, Next, this sheet is cut into, for example, a circular shape.

  Then, the positive electrode and the negative electrode thus prepared are accommodated in a battery case via a separator made of a polyolefin fiber nonwoven fabric or a polyolefin microporous film having a heat resistant temperature of about 150 ° C. A battery is obtained by injecting the liquid.

  In order to further reduce the size and density of the battery thus manufactured, a coin-type battery A shown in FIG. 5 has been developed.

This conventional battery A is a separator in which a positive electrode can 11 made of, for example, stainless steel provided with a disk-shaped positive electrode 11b and a negative electrode can 12 made of, for example, stainless steel provided with a disk-shaped negative electrode 12b are impregnated with an electrolyte. 14 and then, for example, a battery case structure in which the periphery of the positive electrode can 11 and the periphery of the negative electrode can 12 are caulked together via a gasket 15 made of insulating polypropylene resin, for example. ing. Charging / discharging in the positive electrode 11b and the negative electrode 12b is performed via an external connection terminal member attached to the positive electrode can 11 and the negative electrode can 12 (see, for example, Patent Documents 1 and 2 below).
Japanese Unexamined Patent Publication No. 2000-106195 (page 6-12, FIG. 1) JP 2002-198019 (page 3-4, FIG. 1)

  However, when the conventional battery A as shown in Patent Documents 1 and 2 is exposed to a temperature cycle test (for example, −40 ° C. to 85 ° C.) with a temperature range of a few hundred degrees over a long period of time, for example, Due to the difference in coefficient of thermal expansion between the gasket 15 made of polypropylene resin, the positive electrode can 11 and the negative electrode can 12, a gap is generated at the joining portion of the battery case can which is caulked around the positive electrode can 11 and the negative electrode can 12 through the gasket 15. There is a case where the electrolyte solution leaks, and this causes a problem that the battery performance of the battery A is deteriorated or the copper (Cu) wiring on the external electric circuit board is corroded and disconnected by the leaked electrolyte solution. Alternatively, there has been a problem in that moisture enters the inside of the battery A from this gap and deteriorates the battery performance.

  Furthermore, since the conventional battery A has a positive electrode can 11 and a negative electrode can 12 made of stainless steel, the thermal conductivity is high, the battery A is easily affected by the temperature outside the battery A, and the battery performance is likely to deteriorate. There was also a point. That is, when the temperature outside the battery A rises, the electrolyte easily changes greatly following the temperature change outside the battery A, and the desired battery performance cannot be exhibited.

  Accordingly, the present invention has been completed in view of the above-mentioned problems, and its purpose is to deteriorate the battery performance due to leakage of the electrolyte due to the formation of a gap in the joint portion of the battery case due to long-term use. For the battery with excellent mass productivity, the external electric circuit board is not damaged by the leaked electrolyte, the connection to the external electric circuit board is easy, and the battery performance is not affected by the ambient temperature change. It is to provide a case and a battery.

  The battery case of the present invention has a rectangular parallelepiped recess formed in the center of the upper surface, and a base made of ceramics having a first conductor layer and a second conductor layer provided independently on the lower surface, and the recess A first metallization layer formed on the bottom surface of the substrate, a second metallization layer formed on the upper surface of the step formed between the inner surface and the bottom surface of the recess, and the recess in the bottom of the substrate. An intermediate conductor layer formed in parallel to the bottom surface of the first inner conductor formed from the first metallization layer to the first conductor layer via the intermediate conductor layer, and the second And a second inner conductor formed from the metallized layer to the second conductor layer.

  The battery of the present invention is in close contact with the battery case having the above configuration, the positive electrode plate connected to the first metallization layer, and the upper surface of the positive electrode plate via an insulating sheet impregnated with an electrolyte. A negative electrode plate placed and connected to the second metallization layer, and a lid joined so as to cover the concave portion are provided.

  Further, the battery case of the present invention has a base made of ceramics in which a rectangular parallelepiped recess is formed at the center of the upper surface, and the first conductor layer and the second conductor layer are provided independently on the lower surface, A first metallization layer formed on the bottom surface of the recess, a second metallization layer formed around the recess on the top surface of the base, and parallel to the bottom surface of the recess inside the bottom of the base An intermediate conductor layer formed from the first metallization layer to the first conductor layer via the intermediate conductor layer, and the second metallization layer to the second metallization layer. And a second inner conductor formed over the conductor layer.

  The battery of the present invention is in close contact with the battery case having the above-described configuration, a positive electrode plate connected to the first metallization layer, and an insulating sheet impregnated with an electrolyte on the upper surface of the positive electrode plate. The negative electrode plate placed so as to cover the recess, and at least the lower main surface is made conductive, and the lid is connected to the negative electrode plate and the second metallization layer. It is characterized by comprising.

  In the battery of the present invention, preferably, the positive electrode plate is attached to the first metallized layer via a resin layer containing conductive particles bonded so as to cover the upper surface of the first metallized layer. It is electrically connected.

  The battery case of the present invention has a rectangular parallelepiped recess formed at the center of the upper surface, a base made of ceramics on which the first conductor layer and the second conductor layer are provided independently of each other on the lower surface, A first metallization layer formed on the bottom surface, a second metallization layer formed on the top surface of the step formed between the inner surface and the bottom surface of the recess, and a bottom surface of the recess inside the bottom of the substrate. An intermediate conductor layer formed in parallel, a first inner conductor formed from the first metallization layer through the intermediate conductor layer to the first conductor layer, and a second metallization layer to the second conductor layer. And the second inner conductor formed over the surface, the electrolytic solution is accommodated by a base made of ceramics having excellent airtightness and excellent heat resistance, so that the electrolytic solution can be accommodated satisfactorily. Can, temperature cycle Is does not leak electrolyte occurs gap even when exposed to the test. Moreover, since airtightness is maintained, it is possible to effectively prevent moisture, oxygen, or the like that deteriorates battery performance from entering the electrolytic solution from the outside.

  In addition, the substrate is not easily attacked by an electrolytic solution containing an organic solvent, an acid, and the like, and impurities dissolved from the substrate are not mixed in the electrolytic solution, so that the electrolytic solution is not deteriorated. For this reason, battery performance can be maintained satisfactorily.

  Furthermore, since a portion that is caulked through a resin as in the prior art is not required, the outer shape of the battery can be reduced to the limit, which is suitable for recent miniaturization.

  Still further, the first inner conductor formed from the first metallized layer to the first conductor layer through the intermediate conductor layer is formed inside the base in parallel to the bottom surface of the recess. Since the intermediate conductor layer is interposed, the length of the first inner conductor is increased, and the first inner conductor is transmitted from the battery outside (bottom surface of the battery) to the electrolyte inside the battery (recessed portion) via the first inner conductor. Heat can be suppressed. Therefore, even when the temperature of the bottom surface of the battery (outside of the battery) rises, it is possible to suppress the temperature change of the electrolytic solution as much as possible and always exhibit desired battery performance. In addition, the resistance value of the first inner conductor can be made closer to the resistance value of the second inner conductor.

  Further, by forming the first conductor layer and the second conductor layer on the lower surface, the first and second conductor layers are joined to the wiring conductor on the surface of the external electric circuit board via solder. Since the wiring conductor of the flat external electric circuit board and the battery can be easily connected, the mass production of the external electric circuit board is very good.

  The battery of the present invention is placed in close contact with the battery case having the above configuration, the positive electrode plate connected to the first metallization layer, and the upper surface of the positive electrode plate via an insulating sheet impregnated with an electrolyte. And having a negative electrode plate connected to the second metallization layer and a lid joined so as to cover the recess, airtight reliability using the battery case having the above-described configuration is achieved. High and excellent in mass productivity. In addition, desired battery performance can be exhibited, reliability is high, and charging and discharging can be performed stably over a long period of time.

  Further, according to the battery case of the present invention, when the second metallized layer is formed around the recess on the upper surface of the base, the step inside the recess can be omitted, so that the inside of the recess can be used widely and effectively. Therefore, the outer shape of the battery case can be reduced in size.

  In addition, the battery of the present invention includes a battery case having a second metallized layer formed around a recess on the upper surface of the base, a positive electrode plate connected to the first metallized layer, and the positive electrode plate A negative electrode plate placed so as to be in close contact with the upper surface of the substrate through an insulating sheet impregnated with an electrolytic solution, and joined so as to cover the recess, and at least the lower main surface is made conductive, and the negative electrode plate And a lid connected to the second metallization layer, the lid is brought into contact with a wide surface of the lower main surface of the lid made conductive and the negative electrode plate. By connecting the negative electrode plate, the resistance between the negative electrode plate and the lid can be reduced, and charging and discharging can be performed efficiently without causing electrical loss between the negative electrode plate and the lid. Therefore, the electrical characteristics can be improved.

  In the battery of the present invention, preferably, the positive electrode plate is electrically connected to the first metallized layer via a resin layer containing conductive particles bonded so as to cover the upper surface of the first metallized layer. By connecting to the first metallized layer, the corrosive electrolytic solution is blocked by the resin layer containing conductive particles and does not come into contact with the first metallized layer. Can be a thing.

  In addition, since the electrolytic solution is less likely to enter the first metallized layer formation site, there is less possibility of the electrolyte leaking from the first metallized layer formation site to the outside of the battery through the first internal conductor.

  In addition, since the resin layer containing conductive particles has elasticity, even if the positive electrode plate is strongly pressed against the substrate, it is buffered by the resin layer containing conductive particles, and the substrate or the positive electrode plate is damaged. Can be effectively prevented.

  The battery case of the present invention will be described in detail below. 1A is a cross-sectional view showing an example of an embodiment of a battery case of the present invention, and FIG. 1B is a plan view of the battery case of FIG.

  The battery case of the present invention is a base 1 made of ceramics in which a rectangular parallelepiped recess 1a is formed at the center of the upper surface, and a first conductor layer 1d and a second conductor layer 1e are provided independently on the lower surface. A first metallized layer 1b formed on the bottom surface of the recess 1a, a second metallized layer 1c formed on the top surface of the step 1-A formed between the inner surface and the bottom surface of the recess 1a, An intermediate conductor layer 2b-A formed parallel to the bottom surface of the recess 1a inside the bottom of the substrate 1, and from the first metallized layer 1b to the first conductor layer 1d via the intermediate conductor layer 2b-A. The first inner conductor 2b is formed, and the second inner conductor 2c is formed from the second metallized layer 1c to the second conductor layer 1e.

  In FIG. 1, a first metallized layer 1b is formed on the bottom surface of the recess 1a of the substrate 1, and a step 1-A is formed between the inner surface and the bottom surface of the recess 1a. The second metallized layer 1 c is formed, and the first and second conductor layers 1 d and 1 e are formed on the lower surface of the substrate 1.

  Since the first and second conductor layers 1d and 1e are formed on the lower surface of the base 1, the first and second conductor layers 1d and 1e are connected to the wiring conductor on the surface of the external electric circuit board via solder. By bonding, the wiring conductor of the flat external electric circuit board and the battery can be easily connected, so that the mass productivity of the external electric circuit board is improved.

Such a base | substrate 1 consists of ceramics, such as an alumina sintered body, and is produced as follows. For example, when the substrate 1 is made of an alumina sintered body, an organic binder suitable for a raw material powder such as aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), magnesium oxide (MgO), calcium oxide (CaO), etc. Add a solvent and mix to form a slurry. This slurry is formed into a green sheet by a doctor blade method or a calender roll method and cut into a required size. Next, in order to form the concave portion 1a, the step 1-A and the like in a plurality of green sheets selected from them, an appropriate punching process is performed.

  Then, a metal paste mainly composed of a metal powder such as tungsten (W) is printed on these green sheets, and the first metallized layer 1b, the first inner conductor 2b, the first conductor layer 1d, the second A printed pattern to be a conductor layer such as the metallized layer 1c, the second inner conductor 2c, and the second conductor layer 1e is formed, and then green sheets on which these printed patterns are formed are laminated, and the temperature is about 1600 ° C. By baking, the base | substrate 1 provided with the conductor layer is produced.

  The first conductor layer 1d is electrically connected to the first metallized layer 1b via the first inner conductor 2b, and the second conductor layer 1e is second metallized via the second inner conductor 2c. It is electrically connected to the layer 1c. The first conductor layer 1d is used as the positive electrode of the battery, and the second conductor layer 1e is used as the negative electrode. The first conductor layer 1d and the second conductor layer 1e are joined to the wiring conductor on the surface of the external electric circuit board via solder, whereby the battery is electrically connected to the external electric circuit.

  Further, the exposed surfaces of these conductor layers formed on the substrate 1 thus manufactured have a metal excellent in corrosion resistance and wettability with solder, specifically nickel (thickness 1 to 12 μm). A Ni) layer and a gold (Au) layer having a thickness of 0.3 to 5 μm are preferably sequentially deposited by a plating method or the like. Thereby, it can suppress effectively that the metal component of the 1st metallization layer 1b and the 2nd metallization layer 1c which were especially formed inside the case for batteries is easily eluted by the voltage by charging / discharging. In addition, the first and second conductor layers 1d and 1e have improved wettability with solder, and the bonding strength with the wiring conductor on the external electric circuit board via the solder becomes stronger.

  If the thickness of the Ni layer is less than 1 μm, it becomes difficult to prevent the oxidative corrosion of each conductor made of the metallized layer and to effectively prevent the metal component from eluting from the conductor, and the battery performance deteriorates. It becomes easy to do. On the other hand, if the thickness of the Ni layer exceeds 12 μm, it takes a long time to form the plating, so that the mass productivity is likely to be lowered and the electric resistance is likely to be increased.

  Further, if the thickness of the Au layer is less than 0.3 μm, it is difficult to form an Au layer having a uniform thickness, and a portion where the Au layer is extremely thin or a portion where the Au layer is not formed is likely to occur. The effect of preventing oxidative corrosion and the wettability with solder are likely to decrease. If the thickness of the Au layer exceeds 5 μm, it takes a lot of time to form the plating, and the mass productivity tends to decrease.

  The base body 1 made of ceramics is not easily attacked by the electrolytic solution B-4 containing an organic solvent, an acid, etc. Therefore, impurities dissolved from the base body 1 are mixed in the electrolytic solution B-4 and deteriorate the electrolytic solution B-4. I will not let you. For this reason, the battery case which can maintain battery performance favorably can be obtained.

  Further, the first inner conductor 2b is interposed from the first metallized layer 1b through the intermediate conductor layer 2b-A formed inside the bottom of the base 1 in parallel to the bottom surface of the recess 1a. The length of the first inner conductor 2b is longer than the case where the first inner conductor 2b is formed linearly over one conductor layer 1d, and the inside of the battery (recess 1a) from the outside of the battery (the bottom surface of the battery) via the first inner conductor 2b. Heat transmitted to the electrolytic solution B-4 can be suppressed. Therefore, the inside of the battery is hardly affected by the temperature outside the battery. As a result, even when the temperature outside the battery rises, the electrolyte B-4 does not change greatly following the temperature change outside the battery, and the temperature change of the electrolyte B-4 is suppressed as much as possible. Desired battery performance can be exhibited. In addition, the length of the first inner conductor 2b is made closer to the length of the second inner conductor 2c formed from the second metallized layer 1c to the second conductor layer 1e inside the side portion of the base body 1. Therefore, the resistance value of the second inner conductor 2c can be made closer to the resistance value of the first inner conductor 2b.

  Further, since the upper end of the first inner conductor 2b is covered with the lower surface of the first metallized layer 1b, the electrolytic solution B-4 does not directly contact the first inner conductor 2b, Even if slight peeling occurs between the inner conductor 2b and the surrounding ceramic, there is little possibility that the electrolyte B-4 leaks out of the battery through the peeled portion.

  The first inner conductor 2b includes an intermediate conductor layer 2b-A that is parallel to the bottom surface of the recess 1a and a through conductor 2b-B that is continuous with the bottom surface of the recess 1a. As a result, an electric circuit can be routed in the base 1, and the first and second conductor layers 1d and 1e can be formed at desired positions on the base 1.

  The through conductors 2b-B continuous from the intermediate conductor layer 2b-A to the bottom surface of the recess 1a may be divided into a plurality of connections, and the connection reliability can be improved.

  The first inner conductor 2b is composed of the through conductor 2b-B perpendicular to the bottom surface of the recess 1a and the intermediate conductor layer 2b-A parallel to the bottom surface of the recess 1a. And the intermediate conductor layer 2b-A cross at a substantially right angle, and the electrolyte B-4 passes through the slight gap between the penetrating conductor 2b-B and the intermediate conductor layer 2b-A and the surrounding ceramics. Even if it is about to leak into the passage, the passage is bent at a right angle in the middle and the length of the passage becomes longer, so that the structure is difficult to leak out.

  On the upper surface of the substrate 1, ceramics such as an alumina sintered body and a mullite sintered body, aluminum (Al), copper (Cu), carbon, iron (Fe) -Ni-cobalt (Co) alloy, Fe The lid 3 made of a metal such as a Ni alloy is joined by a method such as brazing using Al brazing, silver (Ag) brazing, Au-tin (Sn) soldering, or bonding using a resin adhesive. .

  Next, as another example of the embodiment of the battery case of the present invention, FIG. 2 shows a form in which a second metallized layer 1c is formed around the recess 1a on the upper surface of the base 1. As shown in FIG. In the figure, (a) is a cross-sectional view of the battery case, and (b) is a plan view of the battery case. According to this embodiment, since the step 1-A inside the recess 1a can be omitted, the inside of the recess 1a can be used widely and effectively, so that the outer shape of the battery case can be reduced in size.

  The base 1 is made of ceramics similar to the battery case of FIG. 1, and the lid 3 is made of a conductive material such as Al, Cu, carbon, Fe—Ni—Co alloy, Fe—Ni alloy. Or it consists of ceramics, such as an alumina sintered body and a mullite sintered body, and the metallized layer 3a, such as W, is formed in the lower main surface.

  Preferably, the lid 3 has a metallized layer 3a such as W formed on almost the entire lower main surface of the base 1 side, and is made of the same ceramic as the base 1 such as an alumina sintered body and a mullite sintered body. It is good. The metallized layer 3a is electrically connected to the second metallized layer 1c and joined to the upper surface of the base 1 so as to cover the recess 1a. With this configuration, the upper main surface of the lid 3 is not made conductive, and unnecessary current can be prevented from flowing through the upper surface of the lid 3. Therefore, even if a conductive member contacts the upper main surface of the lid 3, it is possible to effectively prevent problems such as an electrical short circuit from occurring. Further, since the thermal expansion coefficient of the lid 3 is substantially the same as the thermal expansion coefficient of the base body 1, even when heat is applied to the battery case, the stress due to the thermal expansion difference is large at the joint between the base body 1 and the lid body 3. It is possible to prevent the occurrence of breakage such as cracks in the base body 1 and to effectively prevent the breakage of the base body 1 and to provide a battery case having excellent hermetic reliability.

  Next, the battery of the present invention will be described in detail below. FIG. 3 is a cross-sectional view showing an example of a battery according to the present invention using the battery case of FIG. 1 (this is referred to as a battery C), and FIG. 4 is a diagram of the present invention using the battery case of FIG. It is sectional drawing which shows the other example (it is set as the battery D) of embodiment of a battery. Here, B-1 is a positive electrode plate, B-2 is a negative electrode plate, B-3 is an insulating sheet, B-4 is an electrolytic solution, and C and D are batteries.

  The battery C of the present invention includes the battery case of the present invention, a positive electrode plate B-1 connected to the first metallized layer 1b, and an electrolyte B-4 on the upper surface of the positive electrode plate B-1. The lid 3 that is placed so as to be in intimate contact with the insulative insulating sheet B-3 and is connected to the second metallized layer 1c and joined so as to cover the recess 1a. It is equipped with.

  The battery D of the present invention includes a battery case of the present invention, a positive electrode plate B-1 connected to the first metallized layer 1b, and an upper surface of the positive electrode plate B-1 impregnated with an electrolytic solution B-4. The negative electrode plate B-2 placed so as to be in close contact with the insulating sheet B-3 and joined so as to cover the recess 1a, and at least the lower main surface is made conductive, and the negative electrode plate And a lid 3 electrically connected to B-2 and the second metallized layer 1c.

The positive electrode plate B-1 is a plate or sheet containing a positive electrode active material made of LiCoO ₂ or LiMn ₂ O ₄ and a conductive material such as acetylene black or graphite, and the negative electrode plate B-2 Is a plate-like or sheet-like material containing a negative electrode active material made of a carbon material such as coke or carbon fiber.

  The positive electrode plate B-1 is obtained by adding a binder such as polytetrafluoroethylene or polyvinylidene fluoride to the positive electrode active material added with the conductive material, and mixing it to form a slurry. This is a well-known doctor blade method. For example, the sheet is formed into a sheet using, for example, and then cut into a circular shape.

  Similarly, the negative electrode plate B-2 is made into a slurry by adding and mixing a binder such as polytetrafluoroethylene or polyvinylidene fluoride to the negative electrode active material, and this is made into a sheet using a known doctor blade method or the like. Then, the sheet is produced by cutting the sheet into, for example, a circular shape.

  The insulating sheet B-3 is made of a non-woven fabric made of polyolefin fiber, a microporous membrane made of polyolefin, and the like, impregnated with the electrolytic solution B-4, and between the positive electrode plate B-1 and the negative electrode plate B-2. By being disposed between the positive electrode plate B-1 and the negative electrode plate B-2, the electrolytic solution between the positive electrode plate B-1 and the negative electrode plate B-2 is prevented. The movement of B-4 is enabled to allow a current to flow.

  The electrolytic solution B-4 is injected into the batteries C and D from the upper surface of the concave portion 1a using an injection means such as a syringe in a container filled with, for example, argon (Ar) gas that hardly contains moisture. Then, the inside of the batteries C and D can be hermetically sealed by welding the lid 3 to the upper surface of the base 1 after injection.

  The electrolytic solution B-4 is obtained by, for example, dissolving a lithium salt such as lithium tetrafluoroborate or an acid such as hydrochloric acid, sulfuric acid, or nitric acid in an organic solvent such as dimethoxyethane or propylene carbonate.

  Such an electrolytic solution B-4 is highly corrosive and soluble, but by using the battery case of the present invention, the substrate 1 is excellent in chemical resistance. The electrolyte solution B-4 is not easily affected by the electrolyte solution B-4, and impurities dissolved out from the battery case are not mixed in the electrolyte solution B-4 so that the electrolyte solution B-4 is not deteriorated. be able to.

  Further, in the metal case that has been conventionally used, as shown in FIG. 5, the positive electrode can 11 and the negative electrode can 12 are integrated by caulking the periphery of them through a gasket 15 made of polypropylene resin or the like. In the conventional battery, since the caulking portion is present, the caulking portion including the positive electrode can 11, the negative electrode can 12, and the separator 14 needs to have a size of about 2 mm. According to the present invention, the caulking portion Therefore, the external shapes of the batteries C and D can be reduced, which can greatly contribute to miniaturization of the portable device. Further, the airtight reliability is high and the mass productivity is excellent.

  In addition, since the lid 3 can be firmly bonded to the upper surface of the substrate 1 having excellent airtightness and heat resistance by a resin adhesive such as polypropylene, solder bonding, seam welding bonding or the like, the electrolyte can be stored well. Even when exposed to a temperature cycle or the like, a gap is not generated and the electrolyte does not leak. Moreover, since airtightness is maintained, it is possible to effectively suppress moisture, oxygen, and the like that deteriorate battery performance from entering the electrolyte from the outside.

  Further, by using this battery case, the first metallized layer 1b is formed on the bottom surface of the recess 1a, so that the positive electrode plate B-1 can be easily connected, and the upper surface of the positive electrode plate B-1 is electrolyzed. Place the negative electrode plate placed in close contact with the insulating sheet impregnated with liquid B-4 and connected to the second metallized layer 1c or connected to the lower main surface of the lid. Can be obtained, and it is very good for mass production.

  In the battery D of FIG. 4, the lower main surface of the lid 3 can be brought into contact with the upper surface of the negative electrode plate B-2 to be electrically connected, and the lid 3 and the negative electrode plate B-2 are wide. By connecting the surfaces, the resistance between the negative electrode plate B-2 and the lid 3 can be reduced, and no electrical loss occurs between the negative electrode plate B-2 and the lid 3. Since charging and discharging can be performed efficiently, the electrical characteristics are excellent, the reliability is higher, and charging and discharging can be performed stably over a long period of time.

  Preferably, in the batteries C and D of the present invention, the positive electrode plate B-1 is first through a resin layer containing conductive particles bonded so as to cover the upper surface of the first metallized layer 1b. The metallization layer 1b is preferably electrically connected.

  The resin layer containing conductive particles is composed of conductive particles and a binder resin that binds the conductive particles. A resin layer containing conductive particles (hereinafter also referred to as a conductive resin layer) contains conductive particles and a binder resin, so that it does not react with the electrolytic solution B-4 and has electrical conductivity. It becomes a functional resin layer. That is, the conductive particles have high electrical conductivity and characteristics such as being chemically stable, and the conductive resin layer has electrical conductivity.

  The mixing ratio of the conductive particles and the binder resin is not particularly limited. That is, when the batteries C and D are formed, if the content of the conductive particles is too small and the electric resistance does not increase too much, the binder resin can be mixed within a range of a mixing ratio that can sufficiently bind the conductive particles. Good. When the content of the conductive particles increases, the conductivity of the conductive resin layer increases, and when the content of the conductive particles decreases, the conductivity decreases. Further, when the content of the conductive particles increases, the content of the binder resin relatively decreases, and the conductive particles cannot be sufficiently bound and supported by the binder resin.

  The binder resin is not particularly limited as long as the conductive particles can be bound, and examples thereof include phenol resins, polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), and the like.

  The type of conductive particles is not particularly limited, and is composed of metal particles that do not react with the electrolytic solution B-4 such as carbon particles or aluminum powder. When the conductive particles are made of carbon particles, it is preferable to contain at least one of carbon black and graphite. By containing at least one of carbon black and graphite, sufficient electrical conductivity is ensured in the conductive resin layer.

  Then, the conductive particles and the binder resin are mixed to form a paste, which is applied from the top surface of the first metallized layer 1b to the bottom surface of the recess 1a, and then dried and bonded to form the conductive resin layer. Form. Alternatively, the paste-like mixture is formed into a sheet shape using a well-known doctor blade method or the like, and cut into a size that can cover the first metallized layer 1b and its surroundings before being completely dried. The sheet is sufficiently adhered over the bottom surfaces of the first metallized layer 1b and the recess 1a to form a conductive resin layer.

  In this way, the conductive resin layer is bonded so as to cover the first metallized layer 1b, and the positive electrode plate B-1 is electrically connected to the first metallized layer 1b via the conductive resin layer thereon. In this case, the corrosive electrolytic solution B-4 is blocked by the conductive resin layer and does not come into contact with the first metallized layer 1b, and the surface of the first metallized layer 1b by metal plating or the like on the electrolytic solution B-4 Protection can be simplified.

  In addition, since the electrolytic solution B-4 is less likely to enter the formation site of the first metallized layer 1b, the electrolytic solution B-4 passes from the formation site of the first metallized layer 1b to the batteries C, The possibility of leakage to the outside of D can be reduced. Further, since the conductive resin layer has elasticity, even if the positive electrode plate B-1 is strongly pressed against the base body 1, it is buffered by the conductive resin layer, so that the base body 1 or the positive electrode plate B-1 is damaged. Can be effectively prevented.

  Preferably, the conductive resin layer may be provided so as to cover the lower surface of the lid 3 and the surface of the second metallized layer 1c, and the negative electrode plate B-2 is interposed via the conductive resin layer. The second metallized layer 1c or the conductive portion on the lower surface of the lid 3 may be electrically connected. With this configuration, the lower surface of the lid 3 and the surface of the second metallized layer 1c can be prevented from being in direct contact with the corrosive electrolyte B-4, and the negative electrode plate B-2 can be interposed via the conductive resin layer. The lid 3 can be elastically held. Thereby, without damaging the negative electrode plate B-2 with a crack or the like, the battery elements inside the batteries C and D can be held so as not to be misaligned.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

(A) is sectional drawing which shows an example of embodiment of the case for batteries of this invention, (b) is a top view of (a). (A) is sectional drawing which shows the other example of embodiment of the case for batteries of this invention, (b) is a top view of (a). FIG. 2 is a cross-sectional view of a battery using the battery case of FIG. 1, showing an example of an embodiment of the battery of the present invention. FIG. 4 is a cross-sectional view of a battery using the battery case of FIG. 2, showing another example of the embodiment of the battery of the present invention. It is sectional drawing which shows the example of the conventional battery.

Explanation of symbols

1: Base 1a: Recessed portion 1-A: Step 1b: First metallized layer 1c: Second metallized layer 1d: First conductor layer 1e: Second conductor layer 2b: First inner conductor 2b-A: Intermediate conductor layer 2c: second inner conductor 3: lid B-1: positive electrode plate B-2: negative electrode plate B-3: insulating sheet B-4: electrolyte C, D: battery

Claims (5)

A rectangular parallelepiped recess is formed in the center of the upper surface, and a base made of ceramics provided with the first conductor layer and the second conductor layer independently of each other on the lower surface, and the first formed on the bottom surface of the recess And a second metallized layer formed on the upper surface of the step formed between the inner surface and the bottom surface of the recess, and formed parallel to the bottom surface of the recess inside the bottom of the base body. An intermediate conductor layer formed from the first metallized layer to the first conductor layer via the intermediate conductor layer, and the second metallized layer to the second conductor. A battery case comprising a second inner conductor formed over the layers. The battery case according to claim 1, the positive electrode plate connected to the first metallization layer, and the positive electrode plate are placed so as to be in close contact with an upper surface of the positive electrode plate via an insulating sheet impregnated with an electrolytic solution. And a negative electrode plate connected to the second metallized layer and a lid joined so as to cover the recess. A rectangular parallelepiped recess is formed in the center of the upper surface, and a base made of ceramics provided with the first conductor layer and the second conductor layer independently of each other on the lower surface, and the first formed on the bottom surface of the recess A second metallization layer formed around the recess on the upper surface of the base, an intermediate conductor layer formed parallel to the bottom of the recess inside the bottom of the base, and A first inner conductor formed from the first metallization layer through the intermediate conductor layer to the first conductor layer, and a second inner conductor formed from the second metallization layer to the second conductor layer. A battery case comprising an inner conductor. The battery case according to claim 3, the positive electrode plate connected to the first metallization layer, and an upper surface of the positive electrode plate placed so as to be in close contact via an insulating sheet impregnated with an electrolytic solution. A negative electrode plate, and a lid that is joined so as to cover the concave portion and that has at least a lower main surface made conductive and connected to the negative electrode plate and the second metallized layer. A battery characterized by that. The positive electrode plate is electrically connected to the first metallized layer through a resin layer containing conductive particles bonded to cover the upper surface of the first metallized layer. The battery according to claim 2 or claim 4.

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