JP4373743B2 - Battery case and battery - Google Patents

Description

  The present invention relates to a thin battery case and battery that can be used for communication equipment such as a mobile phone, can be easily soldered to an external electric circuit board, and can effectively prevent leakage of electrolyte.

  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 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. 3 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 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, for example, an insulating polypropylene resin. 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 via 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.

  Further, in the conventional battery A, when the electrolyte is sealed in the positive electrode can 11 and the negative electrode can 12, bubbles remain inside, and when the bubbles are exposed to the above temperature cycle test, thermal expansion and heat Repeated shrinkage promoted the generation of the gap in the vicinity of the caulked and bonded sites, and as a result, the battery performance was further deteriorated due to electrolyte leakage and moisture penetration.

  Further, in order to perform charging / discharging, the conventional battery A has to connect external connection terminal members up and down and connect the external connection terminal members to the external electric circuit board. Had the problem of being complicated.

  Further, when a high voltage is required, an external connection terminal member or the like must be used to electrically connect the coin-type battery A in series, and the volume including the external connection terminal member becomes large. However, it was contrary to the trend of miniaturization required for portable devices.

  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. The external electric circuit board is not damaged by the leaked electrolyte, and the battery case that is easy to manufacture and the connection with the external electric circuit board are easy and the mass productivity of the external electric circuit board is effective. It is to provide a battery that can be improved.

  In the battery case of the present invention, a rectangular parallelepiped recess is formed in the central portion of the upper surface, a step is formed over the entire circumference between the inner side surface and the bottom surface of the recess, and the first conductor layer and the lower surface are formed on the lower surface. A base made of ceramics provided with a second conductor layer independently of each other, a metallized layer formed on the bottom surface of the recess, and formed from the periphery of the recess on the top surface of the base to the first conductor layer. A first connection conductor, a second connection conductor formed from the metallization layer to the second conductor layer, and a top surface of the step so as to close the recess and from the side surface to the lower main surface. At least the lower main surface and the side surface attached through the resin bonding material to the outer periphery are made conductive, and the side surface and the first connection conductor are electrically connected through the conductive resin. Connected And it is characterized in that it comprises a lid.

  The battery of the present invention includes a battery case of the present invention, a positive electrode plate placed in close contact with the metallized layer, and a porous insulating sheet impregnated with an electrolyte on the upper surface of the positive electrode plate. And a negative electrode plate that is placed in close contact with each other and whose upper surface is in close contact with and electrically connected to the lower main surface of the lid.

  According to the battery case of the present invention, the base made of ceramics having excellent airtightness and heat resistance, and fitted into the upper surface of the step so as to close the recess, and the resin bonding from the side surface to the outer peripheral portion of the lower main surface Since the electrolytic solution is stored in the battery case formed by the lid attached through the material, a gap is generated in the battery case even when exposed to the temperature cycle test, and the electrolytic solution There is no leakage, and the battery case can be satisfactorily accommodated with the electrolyte. Moreover, since moisture, oxygen, or the like that deteriorates the characteristics of the electrolytic solution does not enter from the gap, deterioration of the electrolytic solution can be suppressed.

  Ceramics have excellent chemical resistance, and the substrate made of ceramics is not easily attacked by electrolytes containing organic solvents, acids, etc., and impurities dissolved from the battery case are not mixed in the electrolyte. Does not deteriorate. For this reason, battery performance can be maintained satisfactorily.

  Furthermore, by providing both the first and second conductor layers that are electrically connected to the positive and negative electrode plates of the battery on the lower surface of the base, external electric terminals can be used without using connection means such as external connection terminal members. It becomes possible to easily connect to the wiring conductor on the surface of the circuit board by the surface mounting method, and the mass productivity of the external electric circuit board on which the battery is mounted can be greatly improved.

  Further, the lid is fitted so as to close the recess on the upper surface of the step formed over the entire circumference between the inner surface and the bottom surface of the recess of the base, and the resin bonding material extends from the side surface to the outer periphery of the lower main surface. A highly reliable hermetic seal is achieved, and the lid is fitted so as to drop into the step, so that the lid can be easily aligned and the mass productivity of the battery can be improved. It can be greatly improved.

  Further, the lower main surface of the lid body can be brought into contact with the upper surface of the negative electrode plate to be electrically connected, and the negative electrode plate and the lid body can be connected by connecting the wide surface of the lid body and the negative electrode plate. The resistance between the negative electrode plate and the lid can be charged and discharged efficiently without causing electrical loss, so it is highly reliable and stable over a long period of time. The battery case can be charged and discharged.

  According to the battery of the present invention, since the battery case of the present invention is provided, a highly reliable airtightness can be obtained, and a battery capable of repeating stable charge and discharge can be obtained, and an external electric circuit can be obtained. The battery can be easily connected to the substrate and can improve the mass productivity of the external electric circuit substrate.

  The battery case of the present invention will be described in detail below. FIG. 1A is a cross-sectional view showing an example of an embodiment of a battery case of the present invention, FIG. 1B is a perspective view of the battery case as viewed from the lower surface side, and FIG. 2 is a battery of the present invention. It is sectional drawing which shows an example of this embodiment. In these drawings, 1 is a base made of ceramics, 1a is a rectangular parallelepiped recess formed in the center of the upper surface of the base 1, 1b is a metallized layer formed on the bottom of the recess 1a, and 1c is an inner surface of the recess 1a. Steps formed between the bottom surface and the bottom surface, C and D are the second and first conductor layers independent of each other provided on the lower surface of the base 1, and 2 is a recess on the upper surface of the step 1c. 2a is a metal layer on the lower main surface of the lid 2; 2b is a metal layer on the side of the lid 2; 3a is first from the periphery of the recess 1a on the upper surface of the base 1; A first connection conductor 3b formed over the conductor layer D, a second connection conductor 3b formed from the metallized layer 1b to the second conductor layer C, and B a battery case. Reference numeral 1b-A denotes an extended portion connected to one end of the metallized layer 1b and formed from the metallized layer 1b to the outside of the base 1, and constitutes a part of the second connecting conductor 3b.

  In the battery case B of the present invention, a rectangular parallelepiped concave portion 1a is formed at the center of the upper surface of the ceramic base 1, and a step 1c is formed over the entire circumference between the inner surface and the bottom surface of the concave portion 1a. The lid 2 is fitted on the upper surface of the step 1c so as to close the recess 1a, and the lid 2 is attached to the outer peripheral portion of the lower main surface from the side surface of the lid 2 via the resin bonding material 5. . Since the lid body 2 is fitted so as to drop into the step 1c, the positioning of the lid body 2 is simple and the mass productivity of the battery is improved. Moreover, since the base body 1 and the lid body 2 are bonded by the resin bonding material 5 regardless of a bonding method such as caulking, the bonding is surely performed and highly reliable airtightness is obtained.

  Further, the first conductor layer D and the second conductor layer C are provided independently on the lower surface of the base body 1, and the first connection conductor is formed in the vertical direction from the periphery of the recess 1 a on the upper surface to the first conductor layer D. 3a is formed, and the second connection conductor 3b is formed from the metallized layer 1b to the second conductor layer C. The lower end of the first connection conductor 3a is electrically connected to the first conductor layer D, and the upper end is connected to the conductive side surface of the lid body 2 via the conductive resin 4, whereby the first connection The conductor 3a constitutes a conductive path for electrically connecting the lid 2 to the first conductor layer D. Further, one end of the second connection conductor 3b is formed as an extending portion 1b-A and connected to the metallized layer 1b, and the other end is electrically connected to the second conductor layer C, whereby the second connection conductor 3 b functions as a conductive path that electrically connects the metallized layer 1 b to the second conductor layer C.

  In the example of FIG. 1B, a part of the first connection conductor 3 a and the second connection conductor 3 b are conductors on the inner surfaces of grooves formed in the vertical direction on the opposite outer surfaces of the base 1. The so-called castoration conductor is formed. A part of the second connection conductor 3b is connected to the extension part 1b-A at the upper end, and the extension part 1b-A and the castellation conductor part constitute the second connection conductor 3b.

  When a part of the first connection conductor 3a and the second connection conductor 3b is a castellation conductor, the lower end portion of the castellation conductor can be joined to the wiring conductor on the external electric circuit board via solder. It is possible to form a good meniscus of solder at the lower end of the castellation conductor to firmly bond the battery case B and the wiring conductor of the external electric circuit board, and visually check the soldered state. Therefore, it is possible to achieve highly reliable joining.

  When the first connection conductor 3a is formed on one outer surface of the base 1 and the second connection conductor 3b is formed on the other outer surface opposite to the one outer surface, the first connection conductor 3a is formed. This is preferable because the maximum insulation distance can be taken between the second connection conductor 3b and the second connection conductor 3b. However, the arrangement is not limited to this, and according to the convenience of connection to the wiring conductor on the external electric circuit board. What is necessary is just to make the optimal arrangement.

  Further, the first connection conductor 3 a and the second connection conductor 3 b may be formed as through conductors provided inside the base body 1. In this case, one or more through conductors that are vertically connected to the inside of the base body 1 from the periphery of the concave portion 1a on the upper surface of the base body 1 to the first conductor layer D are formed as the first connection conductor 3a, and the bottom surface of the concave portion 1a. One or more through conductors that extend vertically from the metallized layer 1b to the second conductor layer C through the bottom surface of the substrate 1 may be formed as the second connection conductor 3b. When the first connection conductor 3a and the second connection conductor 3b are formed by through conductors, the first and second connection conductors 3a and 3b may be protected by the substrate 1 made of ceramics and exposed to the outside air. Therefore, it is possible to maintain a reliable connection without being corroded by outside air during long-term use.

  The first and second connection conductors 3a and 3b are not formed as a single continuous through conductor, but the interior in the direction parallel to the first and second conductor layers D and C formed on the lower surface of the base 1 A connection conductor formed by combining a plurality of wiring layers and perpendicular interlayer connection conductors may be used. As a result, an electric circuit can be routed in the base 1 and the first and second conductor layers D and C can be formed at desired positions on the lower surface of the base 1.

The substrate 1 is made of a ceramic such as an alumina sintered body, a mullite sintered body, or a glass ceramic. When the substrate 1 is made of an alumina sintered body, it is manufactured as follows. First, aluminum oxide (Al ₂ O ₃ ) is used as a main component, and raw material powders such as silicon oxide (SiO ₂ ), magnesium oxide (MgO), calcium oxide (CaO) are added to and mixed with this, and an appropriate amount of organic binder and solvent are further mixed. Etc. are added and mixed to form a slurry. This slurry is formed into a green sheet by a well-known doctor blade method or calendar roll method, and then cut into a required size. Next, in the plurality of green sheets selected from among them, the concave portion 1a, the through-hole serving as the groove for forming the first and second connection conductors 3a and 3b, and the step 1c are formed. The shape is punched.

  Then, a metal paste mainly composed of a metal powder such as tungsten (W) is printed and applied to these green sheets by screen printing or a method of depositing the metal paste on the inner surface of the through hole while sucking from below. A conductor layer to be the layer 1b, the first and second connection conductors 3a and 3b, the first and second conductor layers D and C is formed, and then a green sheet on which these conductor layers are formed is laminated and the first Then, the through-hole portion serving as the groove in which the second connection conductors 3a and 3b are formed is cut into two to form individual laminates, which are fired at a temperature of about 1600 ° C. Produced.

  On the exposed surface of each metal layer formed on the substrate 1 thus produced, a metal excellent in corrosion resistance and wettability with solder, specifically nickel (Ni) having a thickness of 1 to 12 μm. ) 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, even if it exposes to external air, it can prevent that a metal layer is corroded by the water | moisture content etc. which are contained in external air. In particular, in the Ni layer and Au layer formed on the surface of the metallized layer 1b formed inside the battery case B, the metal component of the metallized layer 1b easily elutes into the electrolyte due to the voltage generated by charging and discharging the battery. Is effectively suppressed. Further, the first and second conductor layers D and C are improved in wettability with solder, and the bonding strength with the wiring conductor on the external electric circuit board is made stronger and more reliable.

  If the thickness of the Ni layer is less than 1 μm, it becomes difficult to prevent the oxidative corrosion of each metal layer made of metallization and to effectively prevent the metal component from eluting from the metal layer, and the battery performance is improved. It becomes easy to deteriorate. On the other hand, when the thickness of the Ni layer exceeds 12 μm, it takes a long time to form by the plating method, 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. On the other hand, if the thickness of the Au layer exceeds 5 μm, it takes a long time to form by the plating method, and the mass productivity tends to be lowered.

  Formed on the lower surface of the base 1 are first and second conductor layers D and C electrically connected to the lid 2 and the metallized layer 1b through first and second connection conductor conductors 3a and 3b, respectively. Has been. These first and second conductor layers D and C are joined to the wiring conductor on the surface of the external electric circuit board via solder.

  In the battery case B of the present invention, the first and second conductor layers D and C may each be divided into a plurality. Thereby, the contact surfaces of the first and second conductor layers D and C and the wiring conductor on the external electric circuit board can be divided into small portions, and when the battery case B is soldered to the external electric circuit board, It is possible to suppress the heat from the molten solder from being transmitted to the first and second conductor layers D and C. As a result, the thermal stress generated in the battery case B can be effectively suppressed, and the airtight reliability of the battery case B can be greatly improved.

  Next, the lid body 2 is composed of a metal plate such as an iron (Fe) -nickel (Ni) -cobalt (Co) alloy or an Fe-Ni alloy, an alumina sintered body similar to the substrate 1, a mullite sintered body, When it consists of ceramics, such as glass ceramics, and consists of a metal plate, a metal plate is stamped out to a required dimension shape, and it manufactures by providing metal plating layers, such as Ni, on the surface. When the lid 2 is made of ceramics, a green sheet having a predetermined thickness obtained in the same manner as in the production of the base 1 is punched into a predetermined shape, and then at least the lower main surface and side surfaces of the lid 2 The lid 2 on which the metal layers 2a and 2b are formed is manufactured by depositing a metal paste mainly composed of a metal powder such as tungsten (W) on the substrate by screen printing or the like and baking it at a temperature of about 1600 ° C. Is done. A part of the metal layer 2 b connected to the first connection conductor 3 a may be formed over the upper main surface of the lid 2.

  When the lid 2 is made of a metal plate, it is not necessary to form the lower main surface and the side metal layers 2a and 2b connected to the negative electrode plate, and the process is simplified, compared to the case of the ceramic plate. And the internal resistance of the battery can be reduced.

  When the lid 2 is made of ceramic, the thermal expansion coefficient of the lid 2 is almost the same as the thermal expansion coefficient of the base 1, so that even if heat is applied to the battery case B, the base 1 and the lid 2 It is possible to prevent a stress due to a difference in thermal expansion from being greatly applied to the joint portion, and to effectively prevent breakage such as a crack in the base body 1 and the lid body 2 and the joint portion thereof, and has excellent hermetic reliability. The battery case B can be obtained. Further, if a metal layer such as W is not formed on the upper main surface of the lid 2, the upper main surface of the lid 2 is not made conductive and prevents unnecessary current from flowing on the upper surface of the lid 2. can do. Therefore, even if a conductive member contacts the upper main surface of the lid 2, it is possible to effectively prevent problems such as an electrical short circuit from occurring.

  Here, the first connection conductor 3a and the side surface 2b of the lid 2 can be easily electrically connected by a conductive resin 4 such as a silver epoxy resin. The conductive resin 4 may be deposited and applied from the metal layer 2b on the side surface of the lid body 2 to the first connection conductor 3a by a method such as brushing. The metal layer 2a on the lower main surface connected to can be connected to the first connection conductor 3a.

  Next, the battery of the present invention will be described in detail below. FIG. 2 is a cross-sectional view showing an example of an embodiment of the battery of the present invention. In FIG. 2, 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, 2 is a lid, 4 is a conductive resin, 5 is a resin bonding material, and E is a battery. Parts indicating the same parts as the other battery case B are denoted by the same reference numerals.

  The battery E of the present invention has the battery case B and a positive electrode placed on the metallized layer 1b so as to be in close contact with the metallized layer 1b through a bonding material (not shown) containing, for example, carbon as a main component. The plate B-1 is placed so as to be in close contact with the upper surface of the positive electrode plate B-1 via a porous insulating sheet B-3 impregnated with the electrolytic solution B-4, and the upper surface is the lid 2 Similarly, a negative electrode plate B-2 that is in close contact with and electrically connected to the lower main surface of the lower main surface via a bonding material mainly composed of carbon is provided.

  As a result, the battery E becomes a battery E having a highly reliable airtightness using the battery case B of the present invention and capable of repeating stable charging and discharging, and the first and second conductors. Since the layers D and C are provided, it can be easily connected to the wiring conductor of the external electric circuit board with solder or the like, and the mass productivity of the external electric circuit board is excellent.

The positive electrode plate B-1 is a plate or sheet having a positive electrode active material such as 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 It is a plate or sheet 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 shape using, for example, and then cut into a square 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 square 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 contact between the positive electrode plate B-1 and the negative electrode plate B-2 is prevented, and the movement of lithium ions between the positive electrode plate B-1 and the negative electrode plate B-2 is prevented. Make it possible.

  Next, after placing the positive electrode plate B-1 on the metallized layer 1b and placing the negative electrode plate B-2 on the upper surface of the insulating sheet B-3 via the insulating sheet B-3, the conductive resin 4 The outer peripheral portion of the side surface and the lower main surface of the lid body 2 on which no coating is formed is bonded to the base body 1 by a resin bonding material 5 having thermoplasticity such as polypropylene or polyether ether ketone. At the time of bonding, a frame-shaped preform of the resin bonding material 5 is placed on the upper surface of the step 1c, the lid body 2 is placed on the upper surface, and then the metallized layer 1b, the positive electrode plate B-1, The insulating sheet B-3, the negative electrode plate B-2, and the metal layer 2a on the lower main surface of the lid body 2 were held at 140 to 150 ° C. while lightly pressing the upper surface of the lid body 2 so as to be in close contact with each other. The resin bonding material 5 is softened in a furnace filled with argon (Ar) gas or nitrogen (N2) to attach the lid 2 to the upper surface of the step 1c.

  In the battery E of the present invention, a through hole 1d is preferably formed in the side surface or bottom surface of the base body 1 or the lid body 2. Thereby, when injecting the electrolyte B-4 into the battery case B, the electrolyte B-4 can be injected from the through hole 1d, so that the adjustment of the injection speed and the injection amount is facilitated. Large bubbles are not generated inside. Thus, a large stress due to the thermal expansion of the bubbles is not applied to the inside of the battery E, and it is possible to effectively prevent the battery case B from being cracked.

  After the electrolyte B-4 is injected into the battery E from the through-hole 1d, for example, by filling the through-hole 1d as a sealing material with a resin that is less susceptible to the electrolyte B-4 such as polypropylene resin, The inside of the battery E can be hermetically sealed.

  When injecting the electrolytic solution B-4, if the surface of the substrate 1 provided with the through hole 1d is turned up, no bubbles are left inside the battery case B, and the production can be performed with high yield. .

  The electrolytic solution B-4 is obtained by 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 E of the present invention, the substrate 1 made of ceramics is excellent in chemical resistance, and an organic solvent, acid, etc. In addition, since the impurities dissolved from the battery case B are not mixed in the electrolytic solution B-4, the electrolytic solution B-4 is not deteriorated. For this reason, battery performance can be maintained satisfactorily.

  Further, in a battery case using a conventional battery case made of stainless steel, as shown in FIG. 3, the positive electrode can 11 and the negative electrode can 12 are caulked around them via a gasket 15 made of polypropylene resin or the like. Since the thickness of the caulked portion is about 2 mm in combination with the positive electrode can 11, the negative electrode can 12 and the separator 14, according to the present invention, there is no caulking portion. The outer shape of the battery E can be reduced, which can greatly contribute to the reduction in size and thickness of the portable device.

  Furthermore, according to the battery E, the electrolytic solution B-4 is contained in the battery case B formed by the base body 1 made of ceramics and the lid body 2 firmly attached to the base body 1 via the resin bonding material 5. Therefore, even when exposed to a temperature cycle test, the battery case B does not leak due to cracks or the like in the battery case B due to thermal stress, and the electrolyte B-4 does not leak. It can be.

  Further, the lower main surface of the lid 2 can be brought into contact with the upper surface of the negative electrode plate B-2 to be electrically connected, and the wide surface of the lid 2 and the negative electrode plate B-2 is connected. As a result, the resistance between the negative electrode plate B-2 and the lid 2 can be greatly reduced, and the negative electrode plate B-2 and the lid 2 can be efficiently charged without causing electrical loss. Since the battery can be discharged, the battery E is highly reliable and can be stably charged and discharged over a long period of time.

  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. For example, in the present invention, the material of the substrate 1 made of the ceramic of the battery case B has been described as an alumina sintered body, but may be made of other ceramics such as an aluminum nitride (AlN) sintered body or glass ceramics. In the case of an AlN sintered body, heat during operation can be efficiently dissipated to the outside.

  Moreover, although the battery E using the battery case B having one recess 1a has been described, the battery case B having a plurality of recesses 1a may be used. In this case, the lid 2 covers all the recesses 1a. What is necessary is just to make it the sheet | seat cover body 2 or the several cover body 2 which covers each recessed part 1a. When the battery case B having a plurality of recesses 1a is used in this way, the battery E produced in each recess 1a can be connected in parallel to obtain a high-capacity battery E, which is connected in series. Thus, a battery E that can supply a high voltage can be obtained.

  According to the present invention, the elements of the lithium battery that are conventionally housed in a metal can can be housed in a ceramic substrate, so that the size of the lithium battery can be reduced, and the electrolyte can be held reliably over a long period of time. In addition, the lid can be joined with high precision and the connection to the external electric circuit board is simple and reliable, so that it can be used for consumer applications such as calculators, watches, and mobile phones that have been used in the past. In addition, it may be used for industrial purposes such as in-vehicle use, which is used under more severe conditions.

An example of embodiment of the battery case of this invention is shown, (a) is sectional drawing of a battery case, (b) is the perspective view which looked at the battery case from the lower surface side. It is sectional drawing which shows an example of embodiment of the battery of this invention. It is sectional drawing which shows the example of the conventional coin type battery.

Explanation of symbols

1: Base 1a: Recess 1b: Metallized layer 1b-A: Extension 1c: Step 2: Lid 2a: Metal layer on lower main surface 2b: Metal layer on side 3a: First connecting conductor 3b: Second Connecting conductor 4: conductive resin 5: resin bonding material B: battery case B-1: positive electrode plate B-2: negative electrode plate B-3: insulating sheet B-4: electrolyte C: second conductor Layer D: First conductor layer E: Battery

Claims (2)

A rectangular parallelepiped recess is formed in the center of the upper surface, a step is formed over the entire circumference between the inner surface and the bottom surface of the recess, and the first conductor layer and the second conductor layer are independent of each other on the lower surface. A base made of ceramics, a metallization layer formed on the bottom surface of the recess, a first connection conductor formed from the periphery of the recess on the top surface of the base to the first conductor layer, The second connecting conductor formed from the metallized layer to the second conductor layer, and the upper surface of the step are fitted so as to close the recess, and the resin is bonded from the side surface to the outer peripheral portion of the lower main surface. And a lid body in which at least the lower main surface and the side surface are made conductive and the side surface and the first connection conductor are electrically connected via a conductive resin. Have Battery case according to claim. The battery case according to claim 1, a positive electrode plate placed so as to be in close contact with the metallized layer, and a porous insulating sheet impregnated with an electrolyte solution on the upper surface of the positive electrode plate And a negative electrode plate having an upper surface closely attached to and electrically connected to the lower main surface of the lid.

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