JP4583014B2 - Battery case and battery - Google Patents

Description

  The present invention relates to a battery case and battery used for a rechargeable battery, 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. For example, lithium cobaltate (LiCoO ₂ ) or lithium manganate (LiMn ₂ O ₄ ) is used as the positive electrode active material, and acetylene black (AB) or graphite is used as the conductive material. 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. The sheet is formed and then cut into, for example, 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 a circular shape, for example.

  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 pouring the liquid.

  In order to further reduce the size and density of the battery thus manufactured, a coin-type battery A shown in FIG. 6 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).
JP 2000-106195 A (page 6-12, FIG. 1) JP 2002-198019 A (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 at the center of the upper surface, and is a step formed on the inner surface of the recess, the upper surface of the step being higher than the bottom surface of the recess. has a step located, a substrate made of ceramics which is provided a first conductor layer and second conductor layer independently of each other on the lower surface, the first metallized layer formed on the bottom surface of the recess, the A second metallization layer formed on the upper surface of the step, a first inner conductor formed through the base from the first metallization layer to the first conductor layer, and the second metallization layer and anda second internal conductor formed through said substrate toward said second conductor layer from, and wherein the thermal conductivity of the substrate is not more than 20W / m · K Is.

  In the battery case of the present invention, preferably, the cross-sectional area of the first inner conductor is smaller than the cross-sectional area of the second inner conductor.

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 connected to the second metallization layer while being placed, is characterized in that it comprises a and a lid joined so as to cover the recess.

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 metallized layer formed on the bottom surface of the second metallized layer formed on the upper surface of the substrate, is formed through the base toward said first conductive layer from said first metallized layer A first inner conductor and a second inner conductor formed through the substrate from the second metallization layer to the second conductor layer , and a thermal conductivity of the substrate. Is 20 W / m · K or less.

  In the battery case of the present invention, preferably, the cross-sectional area of the first inner conductor is smaller than the cross-sectional area of the second inner conductor.

The battery of the present invention is in close contact with the battery case having the above-described 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. 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. When, and is characterized in that it comprises a.

  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, From the first metallized layer formed on the bottom surface, the second metallized layer formed on the step formed between the inner surface and the bottom surface of the recess, and from the first metallized layer to the first conductor layer A first inner conductor formed and a second inner conductor formed from the second metallization layer to the second conductor layer, and the substrate has a thermal conductivity of 20 W / m · K or less. As a result, the electrolytic solution is accommodated by a base made of ceramics that is excellent in air tightness and heat resistance, so that the electrolytic solution can be accommodated satisfactorily and a gap is generated even when exposed to a temperature cycle test. Electrolyte leaks That there is no. In addition, since airtightness is maintained, it is possible to effectively prevent moisture, oxygen, and the like that deteriorate battery performance from entering the electrolyte 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.

  Furthermore, since the thermal conductivity of the substrate is as low as 20 W / m · K or less, 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 does not change greatly following the temperature change outside the battery, and the temperature change of the electrolyte is suppressed as much as possible, and the desired battery performance is always exhibited. Can be made.

  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.

  Furthermore, according to the battery case of the present invention, the cross-sectional area of the first inner conductor is smaller than the cross-sectional area of the second inner conductor, so that the first inner conductor is shorter than the second inner conductor. Heat transmitted from the outside of the battery to the electrolyte inside the battery can be suppressed. Therefore, as a result of effectively suppressing the temperature rise inside the battery, the temperature change of the electrolytic solution can be suppressed as much as possible, and desired battery performance can always be exhibited. In addition, the resistance value of the first inner conductor can be made closer to the resistance value of the second inner conductor.

  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.

  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 outer 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, A first inner conductor 2b formed from the first metallized layer 1b to the first conductor layer 1d, and a second inner conductor 2c formed from the second metallized layer 1c to the second conductor layer 1e. The thermal conductivity of the substrate 1 is 20 W / m · K or less.

  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 substrate 1 is made of a ceramic having a thermal conductivity of 20 W / m · K or less, such as an alumina sintered body, and is manufactured as follows. For example, when the substrate 1 is made of an alumina sintered body, an organic binder suitable for raw material powders such as aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO). 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.

In order to set the thermal conductivity of the substrate 1 to 20 W / m · K or less, when the substrate 1 is made of an alumina sintered body, the blending ratio of aluminum oxide (Al ₂ O ₃ ) that is a raw material powder is set. What is necessary is just to be 96 mass% or less.

  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.

  In addition, since the thermal conductivity of the substrate 1 is 20 W / m · K or less, the temperature inside the battery is hardly affected by the temperature outside the battery, and even when the temperature outside the battery rises, the electrolytic solution B− 4 does not change greatly following the temperature change outside the battery. Since the temperature change of the electrolytic solution B-4 does not follow the temperature change outside the battery as much as possible, the discharge voltage of the battery C can be suppressed to a temperature change range that does not decrease to less than 80% of the desired voltage. Battery performance can be exhibited. When the thermal conductivity of the substrate 1 increases beyond 20 W / m · K, the temperature change of the electrolytic solution B-4 follows the temperature change outside the battery, and the battery voltage fluctuates greatly. The discharge voltage of the battery C falls below 80% of the desired voltage, and the desired battery performance cannot be exhibited.

  Further, as shown in the sectional view of FIG. 2, the first inner conductor 2b is shorter than the second inner conductor 2c because the sectional area of the first inner conductor 2b is smaller than the sectional area of the second inner conductor 2c. Heat transmitted to the electrolyte solution inside the battery from the lower surface of the battery via 2b can be reduced. Therefore, as a result of effectively suppressing the temperature rise inside the battery, the temperature change of the electrolytic solution B-4 can be suppressed as much as possible, and desired battery performance can always be exhibited. Incidentally, in the example of the present embodiment, the first inner conductor 2b has a length of 0.25 mm and a diameter of 0.1 mm, and the second inner conductor 2c has a length of 0.75 mm and a diameter of 0.2 mm.

  In addition, since the cross-sectional area of the first inner conductor 2b is smaller than the cross-sectional area of the second inner conductor 2c, the resistance value of the first inner conductor 2b and the resistance value of the second inner conductor 2c are made closer to each other. You can also.

  The first and second inner conductors 2b and 2c are shown as one interlayer connection conductor (penetrating conductor) in FIG. 1 that is perpendicular to the first and second conductor layers 1d and 1e. However, the first and second conductor layers 1d and 1e formed on the lower surface of the substrate 1 may be formed by combining a plurality of internal wiring layers in the direction parallel to the vertical interlayer connection conductors. 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.

  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. 3 shows a form in which a second metallized layer 1c is formed around the recess 1a on the upper surface of the base 1. 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 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 substantially 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 a problem such as an electrical short circuit from occurring. In addition, since the thermal expansion coefficient of the lid 3 is substantially the same as the thermal expansion coefficient of the base body 1, even if heat is applied to the battery case, stress due to the thermal expansion difference is large at the joint between the base body 1 and the lid body 3. Therefore, it is possible to effectively prevent the base body 1 from being damaged such as cracks, and a battery case having excellent hermetic reliability can be obtained.

  Next, the battery of the present invention will be described in detail below. 4 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. 5 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 recess 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 the 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. 6, the positive electrode can 11 and the negative electrode can 12 are integrated by caulking them with 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. 5, 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 high, and charging and discharging can be performed stably over a long period of time.

Examples of the present invention will be described below.
A sample of the battery C having the configuration shown in FIG. 4 was produced as follows.

  In addition to 93%, 94, 95, 95.5, 96, 96.5, and 97% by mass of aluminum oxide, 5mm in length, 5mm in width, and 1mm in height consisting of an alumina sintered body containing silicon oxide, magnesium oxide, and calcium oxide. A base 1 having a rectangular parallelepiped concave portion 1a having a length of 3 mm, a width of 3 mm, and a depth of 0.6 mm was prepared at the center of the upper surface. Then, a positive electrode plate B-1, an insulating sheet B-3, a negative electrode plate B-2, and an electrolytic solution B-4 are inserted into the concave portion 1a, and a longitudinally made of an alumina sintered body having the same purity as that of the base 1 is used. A lid 3 having a thickness of 5 mm, a width of 5 mm, and a thickness of 0.5 mm was sealed to the base 1 using a resin adhesive. The substrate 1 and the lid 3 are made of an alumina sintered body having a purity of 93% by mass. Sample C1, the sample having a purity of 94% by mass is sample C2, the sample having a purity of 95% by mass is sample C3, and the purity is 95.5% by mass. Sample C4, sample C5 having a purity of 96% by mass, sample C6 having a purity of 96.5% by mass, and sample C7 having a purity of 97% by mass.

  Samples C1 to C7 were produced one by one, and the discharge voltage of the battery in an atmosphere at 20 ° C. was measured for these samples. As a result, the discharge voltage of each sample was 3.5V. Next, a temperature cycle test in which each sample was subjected to a temperature cycle of −15 ° C. to 85 ° C. for 10 cycles (1 cycle 60 minutes) was performed using a temperature cycle test apparatus (“TSA-201S” manufactured by Tabay Espec). However, the minimum value of the voltage discharged from each sample was measured at the end of each temperature cycle.

Table 1 shows the lowest measured value of the voltage discharged from each sample and the thermal conductivity of the substrate 1 of each sample for samples C1 to C7.

  From Table 1, when the thermal conductivity of the substrate 1 is greater than 20 W / m · K (C6, C7), the discharge voltage during the temperature cycle test is less than 2.8V, that is, the discharge voltage in an atmosphere of 20 ° C. When it is less than 80%, it becomes lower than the discharge voltage at which a mobile phone or a portable computer using the battery C can operate, and the desired battery performance cannot be exhibited. Therefore, it was found that the thermal conductivity of the substrate 1 should be 20 W / m · K or less in order to suppress the temperature change of the electrolytic solution B-4 as much as possible and to always exhibit the desired battery performance.

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

  INDUSTRIAL APPLICABILITY The present invention can be used as a thin battery case and battery that can be easily connected to an external electric circuit board and can effectively prevent leakage of an electrolytic solution, as used in communication equipment such as a mobile phone.

(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). It is sectional drawing which shows the other example of embodiment of the case for batteries of this invention. (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. 3, showing an example of an 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: Recess 1b: First metallized layer 1c: Second metallized layer 1d: First conductor layer 1e: Second conductor layer 2b: First inner conductor 2c: Second inner conductor 3: Lid B-1: Positive electrode plate B-2: Negative electrode plate B-3: Insulating sheet B-4: Electrolytic solution C, D: Battery

Claims (6)

A rectangular parallelepiped recess is formed at the center of the upper surface, and a step is formed on the inner side surface of the recess, the upper surface of the step being higher than the bottom surface of the recess. a substrate comprising a first conductor layer and a second ceramic conductor layer is provided independently of each other, a first metallized layer formed on the bottom surface of the recess, first formed on the upper surface of the step Two metallized layers, a first inner conductor formed through the substrate from the first metallized layer to the first conductor layer, and from the second metallized layer to the second conductor layer second and the inner conductor, and comprising a battery case, wherein the thermal conductivity of the substrate is not more than 20W / m · K, which is formed through the substrate. The battery case according to claim 1, wherein a cross-sectional area of the first inner conductor is smaller than a cross-sectional area of the second inner conductor. The battery case according to claim 1, the positive electrode plate connected to the first metallization layer, and an upper surface of the positive electrode plate so as to be in close contact via an insulating sheet impregnated with an electrolyte. battery, characterized in that it comprises a negative electrode plate connected to the second metallized layer, a lid joined so as to cover the recess, along with being placed. 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 metallized layer, a second metallized layer formed on the upper surface of the substrate, a first inner conductor formed through the substrate from the first metallized layer to the first conductor layer, and anda second internal conductor formed through said substrate toward said second conductor layer from said second metallization layer, the thermal conductivity of the substrate is less than or equal to 20W / m · K A battery case characterized by being. The battery case according to claim 4, wherein a cross-sectional area of the first inner conductor is smaller than a cross-sectional area of the second inner conductor. The battery case according to claim 4 or 5, the positive electrode plate connected to the first metallization layer, and an upper surface of the positive electrode plate so as to be in close contact via an insulating sheet impregnated with an electrolyte. A negative electrode plate placed thereon, and joined to cover the recess, and at least a lower main surface is made conductive, and a lid connected to the negative electrode plate and the second metallization layer ; A battery comprising:

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