WO2010146700A1 - Sealed battery and battery case for the same - Google Patents

Sealed battery and battery case for the same Download PDF

Info

Publication number
WO2010146700A1
WO2010146700A1 PCT/JP2009/061161 JP2009061161W WO2010146700A1 WO 2010146700 A1 WO2010146700 A1 WO 2010146700A1 JP 2009061161 W JP2009061161 W JP 2009061161W WO 2010146700 A1 WO2010146700 A1 WO 2010146700A1
Authority
WO
WIPO (PCT)
Prior art keywords
case body
sealing member
case
sealed battery
battery
Prior art date
Application number
PCT/JP2009/061161
Other languages
French (fr)
Japanese (ja)
Inventor
鈴木　哲
勝巳 伊藤
Original Assignee
トヨタ自動車株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by トヨタ自動車株式会社 filed Critical トヨタ自動車株式会社
Priority to PCT/JP2009/061161 priority Critical patent/WO2010146700A1/en
Publication of WO2010146700A1 publication Critical patent/WO2010146700A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/147—Lids or covers
    • H01M50/166—Lids or covers characterised by the methods of assembling casings with lids
    • H01M50/169—Lids or covers characterised by the methods of assembling casings with lids by welding, brazing or soldering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/102—Primary casings, jackets or wrappings of a single cell or a single battery characterised by their shape or physical structure
    • H01M50/103—Primary casings, jackets or wrappings of a single cell or a single battery characterised by their shape or physical structure prismatic or rectangular
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a sealed battery in which an electrode plate group and an electrolytic solution are enclosed and sealed, and a battery case thereof. More specifically, the present invention relates to a sealed battery and its battery case, in which the opening of the metal case body is sealed by joining with a sealing plate so that the inside is sealed.
  • a sealed battery in which an electrode plate group and an electrolytic solution are sealed inside a battery case has been used.
  • a container-shaped case main body provided with an opening is covered with a sealing plate having substantially the same shape as the opening and the opening is sealed by welding the seams.
  • a step is provided in the peripheral portion of the sealing plate (see, for example, Patent Document 1), and the laser is irradiated with an angle with respect to the mating surface.
  • Patent Document 2 Various ideas have been made such as (see, for example, Patent Document 2).
  • JP 11-339737 A Japanese Patent Laid-Open No. 2000-133211
  • the conventional sealed battery described above has the following problems.
  • the pressure difference between the inside and outside changes due to gas generated inside the battery, environmental changes such as temperature and pressure.
  • the internal pressure is repeatedly increased and decreased to some extent by the gas generated during charging and discharging. For this reason, the battery case is slightly deformed (swelled or dented) due to the change in the internal / external pressure difference. During this deformation, stress tends to concentrate on the corner position of the battery case.
  • the present invention has been made to solve the problems of the above-described conventional sealed battery and its battery case. That is, the problem is that a sealed battery that can maintain good sealing performance over a long period of time without cracks or fatigue failure even when the battery case is repeatedly deformed due to changes in internal pressure, etc. It is to provide a battery case.
  • a sealed battery includes a case body having an opening on one side and a sealing member that closes the opening of the case body.
  • the thin part along the joining part is formed in a part other than the part, and the thickness of the part located on the side far from the joining part adjacent to the thin part is thicker than the thin part.
  • the thin portion is formed along the joining portion. Since this thin part is thinner than the adjacent part located farther from the joining part, the strength is small. Therefore, when the battery case is deformed due to changes in internal pressure, stress concentrates on the thin part as well as the joint. Therefore, compared with the case where stress is concentrated only at the joint, fatigue at the joint is small. As a result, even when the battery case is repeatedly deformed due to changes in internal pressure, cracks and fatigue failure are unlikely to occur at the joint, and good sealing performance can be maintained over a long period of time.
  • the thin portion is a groove formed in the sealing member. If it is such, manufacture is easy and the intensity
  • the thickness of the sealing member in the thin portion is in the range of 0.5 to 1.5 times the plate thickness of the case body. If it is larger than this, the effect is small. If it is smaller than this, the strength of the thin part will be too small.
  • the wall surface on the edge side of the sealing member in the groove is formed at a position within a range of 1.5 to 2 times the plate thickness of the case body from the edge of the sealing member. It is desirable. The effect is small if it is too close to or far from the edge of the sealing member.
  • the total length of the grooves is preferably 40% or more of the total length of the joints. If it is shorter than this, the effect is small.
  • the groove may be provided over the entire circumference of the joint.
  • the case main body has a flat rectangular shape
  • the groove includes at least a central position in the long side direction on the outer surface of the sealing member, and has the same length along both long sides. Therefore, it is desirable that it is formed at a position that is 20% or less of the length of the short side of the sealing member from the edge of the sealing member. If it is such, an appropriate effect can be acquired about a flat rectangular sealed battery.
  • a battery case having a case main body having an opening on one surface and a sealing member that closes the opening of the case main body.
  • the joint location is welded over the entire circumference, and the sealing member or case body has a thin portion formed along the joint location at a location other than the joint location, and a joint location adjacent to the thin portion.
  • the sealed battery and the battery case in the above aspect of the present invention even if the battery case is repeatedly deformed due to a change in internal pressure or the like, cracks and fatigue breakage are unlikely to occur at the joint portion, and a good seal is obtained over a long period Can maintain sex.
  • the sealed battery 10 of this embodiment has a flat rectangular battery case 11 as shown in FIG.
  • the battery case 11 is obtained by joining a substantially plate-shaped sealing plate 12 to an opening of a bottomed box-shaped case main body 13 having an upper portion opened in the drawing. Furthermore, in the sealed battery 10 of this embodiment, a positive electrode terminal 14 and a negative electrode terminal 15 that are external electrode terminals are attached to the upper portion of the sealing plate 12 in the figure.
  • the electrode body group 16 includes positive and negative electrode bodies and an electrolytic solution.
  • the positive electrode terminal 14 and the negative electrode terminal 15 are connected to the respective electrodes of the electrode assembly 16 inside the battery case 11.
  • a safety valve 18 and a liquid injection port 19 are formed at a position between the positive electrode terminal 14 and the negative electrode terminal 15 in the sealing plate 12.
  • grooves 21 and 21 are formed on both sides of the sealing plate 12 of this embodiment along the peripheral portion on the long side.
  • the groove 21 has a substantially uniform depth and is formed in a straight line parallel to the edge of the sealing plate 12.
  • the groove 21 is a portion formed thinner than the thickness of the portion adjacent to the center side (the side far from the edge) of the sealing plate 12.
  • FIG. 2 is a view showing only the vicinity of the upper sealing plate 12 in the AA end face of FIG.
  • a notch 32 corresponding to the plate thickness t of the case body 13 is formed on the entire periphery of the peripheral edge portion of the lower surface of the sealing plate 12 of this embodiment.
  • the case main body 13 and the sealing plate 12 are overlapped so that the case main body 13 is fitted in the notch 32. Thereby, the edge of the sealing plate 12 and the outer peripheral surface of the case body 13 are aligned so as to be substantially on the same plane.
  • the surfaces aligned and overlapped as described above are joined by welding from the outside. That is, the laser is irradiated from the outside in a substantially horizontal direction to the joint between the upper end surface of the case body 13 and the notch 32 of the sealing plate 12 in FIG. As a result, this point is welded. As a result, a welded portion 31 is formed at the boundary between the sealing plate 12 and the case body 13. The welded portion 31 is a range that is once melted in the welding process and then solidified. The welded portion 31 has a substantially semicircular or semielliptical shape in this figure.
  • the direction along the outer peripheral surface of the sealed battery 10 is sealed by irradiating laser with the position being shifted little by little. That is, a plurality of locations are irradiated at positions adjacent to each other so that the melting ranges of the respective laser irradiations overlap each other. Thereby, the sealing plate 12 and the case main body 13 are sealed without a gap. As a result, the inside of the battery case 11 is sealed.
  • the width (welding depth) in the left-right direction in FIG. 2 of the welded portion 31 differs somewhat depending on the location.
  • the range melted by welding extends deeper than the plate thickness t of the case body 13, it is at most the range of the plate thickness t that contributes substantially to the joining. This is because, when the internal pressure rises and the battery case 11 swells, a force that widens the gap between the notch 32 and the case main body 13 is received at this joint location. Therefore, in this embodiment, the plate thickness t of the case body 13 is used as a parameter corresponding to the welding depth related to joining.
  • the welded portion 31 that is once melted and solidified is slightly less resistant to mechanical deformation such as bending than the other portions of the case body 13. For this reason, it is not preferable that the stress accompanying the deformation of the battery case 11 due to the change of the internal pressure is concentrated at this location. Therefore, in the sealed battery 10 of the present embodiment, in order to receive the stress accompanying the deformation of the battery case 11 instead of the welded portion 31, a portion where the strength is intentionally reduced is formed. Thereby, even when the mechanical deformation of the battery case 11 is repeated by, for example, a cooling / heating cycle, the welded portion 31 is prevented from being broken.
  • the groove 21 is formed along the welded portion 31 in the sealing plate 12 of the battery case 11 of this embodiment, the stress when the battery case 11 is deformed is distributed to the welded portion 31 and the groove 21. Is done. It is desirable that the groove 21 has substantially the same strength as the corresponding welded portion 31. That is, the concentration of stress on the welded portion 31 is suppressed by previously forming a portion having a strength almost as small as the welded portion 31 in the vicinity of the welded portion 31. By doing in this way, the frequency
  • the largest surface of the battery case 11 (the right front surface and the left back surface in FIG. 1) is most deformed as the internal pressure increases and decreases.
  • the amount of deformation at the center is large. Therefore, the stress is concentrated most in the central portion of the long side of the sealing plate 12 in the welded portion 31. Therefore, the groove 21 is preferably provided near the center with respect to the long side of the sealing plate 12. It is not always necessary for the short side or the corner. However, it may be provided to avoid the vicinity of the place where the safety valve 18 and the liquid injection port 19 are arranged.
  • FIG. 3 shows a simplified cross section of the joint between the sealing plate 12 and the case body 13.
  • the welded portion 31 is not shown.
  • a is the distance from the inner surface 25 of the case body 13 to the wall surface 26 on the outer peripheral side of the groove 21
  • b is the thickness of the sealing plate 12 at the bottom portion (the thinnest portion) of the groove 21.
  • t is the plate thickness of the case body 13
  • W is the short side width of the sealing plate 12 (see FIG. 2).
  • the distance a from the inner surface 25 of the case body 13 to the wall surface 26 on the outer peripheral side of the groove 21 is greater than half the plate thickness t of the case body 13 and smaller than the plate thickness t. This is because the effect is small even if the wall surface 26 is too close or too far from the case body 13.
  • the plate thickness t of the case main body 13 is almost uniform everywhere at least at the junction with the sealing plate 12.
  • channel 21 should just be in the range settled in the location outside the safety valve 18 or the liquid injection port 19. Here, it is about half of the plate thickness t.
  • the thickness b in the groove 21 is larger than a half of the plate thickness t of the case main body 13 and smaller than a half of the plate thickness t. Further, the thickness b is smaller than the thickness d of the portion located on the inner peripheral side adjacent to the groove 21 in the sealing plate 12.
  • the distance c between the wall surface 26 on the outer peripheral side of the groove 21 and the edge of the sealing plate 12 is preferably 1/5 or less of the width W (see FIG. 2) on the short side of the sealing plate 12.
  • the grooves 21 are formed in the same shape along the long sides on both sides of the sealing plate 12.
  • the total length L of the length L in the longitudinal direction is preferably 40% or more with respect to the entire outer periphery of the sealing plate 12.
  • the arrangement preferably includes the vicinity of the center in the longitudinal direction.
  • the inventors manufactured a sealed battery of this embodiment and a comparative example in which no groove was formed, and conducted an experiment to compare the two.
  • a cold cycle test and a pressure resistance test were conducted.
  • the thermal cycle test the battery temperature was repeatedly raised and lowered between ⁇ 20 ° C. and 80 ° C. with normal pressure, and the number of cycles until the battery case 11 was destroyed was examined.
  • the pressure resistance test a through hole was formed at a location far from the joint in the case body 13, the internal pressure was increased by injecting gas into the inside, and the internal pressure when the battery case 11 was destroyed was measured. .
  • a sealing plate without a safety valve and a liquid inlet was used.
  • a sealing plate 12 having a width W (corresponding to the thickness of the battery) of about 20 mm and a long side of about 110 mm was used.
  • a battery having a case body 13 with a plate thickness t of 1.2 mm was used.
  • the dimensions a, b, and c related to the arrangement of the grooves 21 described above were set as follows.
  • the battery of the comparative example is the same as that of the example except that the groove 21 is not formed.
  • the length 2L of the groove 21 is about 50% of the circumferential length of the sealing plate 12, that is, 130 mm.
  • the groove width was 0.5 mm.
  • the results of the thermal cycle test were as follows. Here, five examples and comparative examples were manufactured, and the average number of cycles until destruction was calculated. Average value of the number of cycles Example 2153 times Comparative Example 1253 times. From this result, it was confirmed that in this example, the durability performance was very high as compared with the comparative example.
  • Table 1 shows the results of the pressure test. Here, five samples for each of the example and the comparative example were manufactured and tested. And the place where it was first destroyed by the rise of internal pressure and the pressure at that time are shown respectively. As shown in this table, in all the examples, the sealing plate was first destroyed. In other words, it was confirmed that the weld was protected by the groove formed in the sealing plate.
  • the internal pressure increases and decreases due to, for example, the generation of gas due to charging and discharging.
  • the case main body 13 swells, and an opening force is applied to the welded portion 31 between the case main body 13 and the sealing plate 12.
  • the groove 21 is formed in the sealing plate 12
  • the stress is distributed between the welded portion 31 and the groove 21. Therefore, as compared with the case where the stress is concentrated only on the welded portion 31, even if the deformation is repeated, it is less likely to break.
  • the sealed battery is less susceptible to cracking or fatigue failure in the welded portion and can maintain good hermeticity over a long period of time.
  • the battery case 41 of the sealed battery 40 is formed by joining a sealing plate 42 having no groove and a case body 43 having a groove 44.
  • the groove 44 is formed near the upper end of the case body 43 in the drawing along the joint between the sealing plate 42 and the case body 43. Even in such a case, similar to the example of FIG. 1, the stress to the welded portion is dispersed, and a highly durable sealed battery can be obtained.
  • FIG. 5 shows a simplified section of the joint between the sealing plate 42 and the case main body 43 of the sealed battery 40 of this type.
  • the arrangement of the grooves 44 in this example is preferably as shown below using the reference numerals in the figure.
  • the thickness t of the case main body 43 and the width W of the sealing plate 42 at locations other than the grooves 44 are the same as those shown in FIG.
  • f is the thickness of the case body 43 at the groove 44
  • g is the distance from the upper surface of the sealing plate 42 to the upper end of the groove 44
  • h is the lower surface of the sealing plate 42 (from the outside). Is the distance from the upper end of the groove 44 to the upper end of the groove 44.
  • the total length of the grooves 44 is preferably 40% or more with respect to the entire circumference of the sealing plate 42.
  • the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
  • a square groove is illustrated in the above example, the cross-sectional shape of the groove is not limited to this, and may be a triangular groove, a round groove, or the like.
  • one groove is formed along the long side of the sealing plate.
  • a plurality of grooves 51 may be formed.
  • the grooves have a uniform depth, but the depth may be different depending on the location. For example, a deeper groove closer to the center may be used.
  • the present invention is also applied to a sealed battery in which the welding surfaces of the sealing plates 12 and 42 and the case main bodies 13 and 43 are parallel to the side surfaces of the case main bodies 13 and 43, respectively.
  • the sealing plates 12 and 42 or the case main bodies 13 and 43 the grooves 21 and 44 may be provided in the vicinity of the welded portions in the same manner as in the above embodiment.
  • the shape of the battery case is not limited to a flat rectangular shape, but can be applied to a cylindrical shape or the like.

Abstract

A sealed battery (10) is provided with a case body (13) having an opening in one surface thereof, and also with an opening sealing plate (12) for closing the opening of the case body (13).  The opening is sealed, with an electrode group (16) contained in the case body (13).  A joint between the opening of the case body (13) and the opening sealing plate (12) is welded along the entire length of the joint.  Either the opening sealing plate (12) or the case body (13) has formed therein a groove (21) located at a portion other than the joint and extending along the joint and is adapted such that the thickness of a portion adjacent to the groove (21), at a position on the side away from the joint, is greater than the thickness of the portion of the groove (21).  Cracks and fatigue breakage are less likely to occur in the joint even if the battery case (11) is repeatedly deformed by a change in the pressure in the battery case (11), so that the battery case (11) can be excellently kept sealed for a long time period.

Description

密閉型電池及びその電池ケースSealed battery and its battery case
　本発明は，電極板群と電解液とを内部に封入して密封した密閉型電池及びその電池ケースに関する。さらに詳細には，ともに金属製のケース本体の開口が，封口板との接合によって封止されることにより，内部が密閉されている密閉型電池及びその電池ケースに関するものである。 The present invention relates to a sealed battery in which an electrode plate group and an electrolytic solution are enclosed and sealed, and a battery case thereof. More specifically, the present invention relates to a sealed battery and its battery case, in which the opening of the metal case body is sealed by joining with a sealing plate so that the inside is sealed.
　従来より，電池ケースの内部に電極板群や電解液を密封した密閉型電池が使用されている。例えば，開口部が設けられた容器形状のケース本体に，その開口部とほぼ同形の封口板を被せ，それらの合わせ目を溶接することによって開口部を封じたものがある。この種の密閉型電池では，溶接部の密閉性を確保するために，封口板の周縁部に段差を設ける（例えば，特許文献１参照。），合わせ面に対して角度を設けてレーザを照射する（例えば，特許文献２参照。）等の様々な工夫がなされてきた。 Conventionally, a sealed battery in which an electrode plate group and an electrolytic solution are sealed inside a battery case has been used. For example, there is a case in which a container-shaped case main body provided with an opening is covered with a sealing plate having substantially the same shape as the opening and the opening is sealed by welding the seams. In this type of sealed battery, in order to ensure the sealing performance of the welded portion, a step is provided in the peripheral portion of the sealing plate (see, for example, Patent Document 1), and the laser is irradiated with an angle with respect to the mating surface. Various ideas have been made such as (see, for example, Patent Document 2).
特開平１１－３３９７３７号公報JP 11-339737 A 特開２０００－１３３２１１号公報Japanese Patent Laid-Open No. 2000-133211
　しかしながら，前記した従来の密閉型電池には，以下のような問題点があった。密閉型電池では，電池内部で発生するガスや，気温，気圧等の環境変化などが原因で，内外の圧力差が変化する。特に，二次電池では，充放電に伴い発生するガスにより，ある程度，内圧の上下が繰り返される。そのため，この内外圧差の変化によって，電池ケースは多少変形（ふくらんだりへこんだり）する。この変形時には，電池ケースの角位置に応力が集中しやすい。 However, the conventional sealed battery described above has the following problems. In a sealed battery, the pressure difference between the inside and outside changes due to gas generated inside the battery, environmental changes such as temperature and pressure. In particular, in the secondary battery, the internal pressure is repeatedly increased and decreased to some extent by the gas generated during charging and discharging. For this reason, the battery case is slightly deformed (swelled or dented) due to the change in the internal / external pressure difference. During this deformation, stress tends to concentrate on the corner position of the battery case.
　さらに，上記のような扁平角型の電池ケースの場合では，電池ケースの角位置に封口板とケース本体との合わせ目がある。そして，その箇所は，全周にわたって溶接によって接合されている。そのため，使用によって接合箇所には繰り返し応力が集中することが避けられない。 Furthermore, in the case of the flat rectangular battery case as described above, there is a joint between the sealing plate and the case body at the corner of the battery case. And the location is joined by welding over the perimeter. For this reason, it is inevitable that repeated stresses concentrate at the joints due to use.
　その一方で，溶接によって一旦溶融しその後に凝固した箇所には，どのような溶接条件であったにせよ，「ひけ」による引っ張り応力がある程度残留している。また，一度溶融した時点でそれまでの組織が破壊されているため，靭性が低下した状態となっている。そのため，電池ケースの他の部分と比較して，この接合箇所は，疲労に対する強度が低い。このことから，内圧の上下による変形が繰り返されると，この接合箇所を起点としたクラックや疲労破壊が発生するおそれがあるという問題点があった。 On the other hand, the tensile stress due to “sink” remains to some extent in the welded part once melted by welding and then solidified. In addition, the toughness is in a reduced state because the previous structure has been destroyed once it has melted. Therefore, compared with other parts of the battery case, this joint location has a low strength against fatigue. For this reason, there is a problem that cracks and fatigue fractures starting from this joint may occur if deformation due to the internal pressure is repeated.
　本発明は，前記した従来の密閉型電池及びその電池ケースが有する問題点を解決するためになされたものである。すなわちその課題とするところは，内圧の変化等による電池ケースの変形が繰り返されても，接合箇所にクラックや疲労破壊が発生しにくく，長期間にわたって良好な密閉性を維持できる密閉型電池及びその電池ケースを提供することにある。 The present invention has been made to solve the problems of the above-described conventional sealed battery and its battery case. That is, the problem is that a sealed battery that can maintain good sealing performance over a long period of time without cracks or fatigue failure even when the battery case is repeatedly deformed due to changes in internal pressure, etc. It is to provide a battery case.
　この課題の解決を目的としてなされた本発明の一態様における密閉型電池は，一面が開口部となっているケース本体と，ケース本体の開口部を塞ぐ封口部材とを有し，ケース本体に発電要素を収納して封口されている密閉型電池であって，ケース本体の開口部と封口部材との接合箇所が，全周にわたって溶接されているものであり，封口部材またはケース本体は，接合箇所以外の箇所に，接合箇所に沿った薄肉部が形成されているとともに，薄肉部に隣接して接合箇所から遠い側に位置する箇所の厚さが，薄肉部より厚いものである。 In order to solve this problem, a sealed battery according to an aspect of the present invention includes a case body having an opening on one side and a sealing member that closes the opening of the case body. A sealed battery that contains elements and is sealed, in which the joints between the opening of the case body and the sealing member are welded over the entire circumference. The thin part along the joining part is formed in a part other than the part, and the thickness of the part located on the side far from the joining part adjacent to the thin part is thicker than the thin part.
　上述の一態様における密閉型電池によれば，薄肉部が接合箇所に沿って形成されている。この薄肉部は，隣接して接合箇所から遠い側に位置する箇所より薄くなっているので，強度が小さい。そのため，内圧の変化により電池ケースが変形した場合に，接合箇所とともに薄肉部にも応力が集中する。従って，接合箇所のみに応力が集中する場合に比較すると，接合箇所の疲労が小さい。これにより，内圧の変化等による電池ケースの変形が繰り返されても，接合箇所にクラックや疲労破壊が発生しにくく，長期間にわたって良好な密閉性を維持できるものとなっている。 According to the sealed battery in one aspect described above, the thin portion is formed along the joining portion. Since this thin part is thinner than the adjacent part located farther from the joining part, the strength is small. Therefore, when the battery case is deformed due to changes in internal pressure, stress concentrates on the thin part as well as the joint. Therefore, compared with the case where stress is concentrated only at the joint, fatigue at the joint is small. As a result, even when the battery case is repeatedly deformed due to changes in internal pressure, cracks and fatigue failure are unlikely to occur at the joint, and good sealing performance can be maintained over a long period of time.
　さらに，本発明の一態様では，薄肉部が，封口部材に形成されている溝であることが望ましい。このようなものであれば，製造が容易であり，薄肉部の強度を適切に調整することができる。 Furthermore, in one aspect of the present invention, it is desirable that the thin portion is a groove formed in the sealing member. If it is such, manufacture is easy and the intensity | strength of a thin part can be adjusted appropriately.
　さらに，本発明の一態様では，薄肉部における封口部材の厚さは，ケース本体の板厚の０．５～１．５倍の範囲内であることが望ましい。これより大きいと効果が小さい。これより小さいと，薄肉部の強度が小さくなりすぎる。 Furthermore, in one aspect of the present invention, it is desirable that the thickness of the sealing member in the thin portion is in the range of 0.5 to 1.5 times the plate thickness of the case body. If it is larger than this, the effect is small. If it is smaller than this, the strength of the thin part will be too small.
　さらに，本発明の一態様では，溝における封口部材の縁辺側の壁面は，封口部材の縁辺から，ケース本体の板厚の１．５～２倍の範囲内の距離の位置に形成されていることが望ましい。封口部材の縁辺に近すぎても遠すぎても効果は小さい。 Furthermore, in one aspect of the present invention, the wall surface on the edge side of the sealing member in the groove is formed at a position within a range of 1.5 to 2 times the plate thickness of the case body from the edge of the sealing member. It is desirable. The effect is small if it is too close to or far from the edge of the sealing member.
　さらに，本発明の一態様では，溝の長さの合計は，接合箇所の全長の４０％以上であることが望ましい。これより短いと効果が小さい。溝は，接合箇所の全周にわたって設けられていても良い。 Furthermore, in one aspect of the present invention, the total length of the grooves is preferably 40% or more of the total length of the joints. If it is shorter than this, the effect is small. The groove may be provided over the entire circumference of the joint.
　さらに，本発明の一態様では，ケース本体が扁平角形のものであって，溝は，封口部材の外面に，少なくとも長辺方向の中央位置を含んで，両長辺に沿ってそれぞれ同じ長さで，形成されているものであり，封口部材の縁辺から，封口部材の短辺の長さの２０％以下の位置に形成されているものであることが望ましい。このようなものであれば，扁平角形の密閉型電池について，適切な効果を得ることができる。 Furthermore, in one aspect of the present invention, the case main body has a flat rectangular shape, and the groove includes at least a central position in the long side direction on the outer surface of the sealing member, and has the same length along both long sides. Therefore, it is desirable that it is formed at a position that is 20% or less of the length of the short side of the sealing member from the edge of the sealing member. If it is such, an appropriate effect can be acquired about a flat rectangular sealed battery.
　また，本発明の他の態様は，一面が開口部となっているケース本体と，ケース本体の開口部を塞ぐ封口部材とを有する電池ケースであって，ケース本体の開口部と封口部材との接合箇所が，全周にわたって溶接されるものであり，封口部材またはケース本体は，接合箇所以外の箇所に，接合箇所に沿った薄肉部が形成されているとともに，薄肉部に隣接して接合箇所から遠い側に位置する箇所の厚さが，薄肉部より厚いものである電池ケースである。 According to another aspect of the present invention, there is provided a battery case having a case main body having an opening on one surface and a sealing member that closes the opening of the case main body. The joint location is welded over the entire circumference, and the sealing member or case body has a thin portion formed along the joint location at a location other than the joint location, and a joint location adjacent to the thin portion. This is a battery case in which the thickness of the part located on the far side is thicker than the thin part.
　本発明の上記態様における密閉型電池及びその電池ケースによれば，内圧の変化等による電池ケースの変形が繰り返されても，接合箇所にクラックや疲労破壊が発生しにくく，長期間にわたって良好な密閉性を維持できる。 According to the sealed battery and the battery case in the above aspect of the present invention, even if the battery case is repeatedly deformed due to a change in internal pressure or the like, cracks and fatigue breakage are unlikely to occur at the joint portion, and a good seal is obtained over a long period Can maintain sex.
本形態に係る密閉型電池を示す斜視図である。It is a perspective view which shows the sealed battery which concerns on this form. 封口板とケース本体との接続箇所を示す端面図である。It is an end view which shows the connection location of a sealing board and a case main body. 封口板とケース本体との接続箇所の一部を示す断面図である。It is sectional drawing which shows a part of connection location of a sealing board and a case main body. 密閉型電池の他の例を示す斜視図である。It is a perspective view which shows the other example of a sealed battery. 封口板とケース本体との接続箇所の一部を示す断面図である。It is sectional drawing which shows a part of connection location of a sealing board and a case main body. 分断された溝の例を示す説明図である。It is explanatory drawing which shows the example of the parted groove | channel. 封口板とケース本体との接続箇所の他の例を示す断面図である。It is sectional drawing which shows the other example of the connection location of a sealing board and a case main body. 封口板とケース本体との接続箇所の他の例を示す断面図である。It is sectional drawing which shows the other example of the connection location of a sealing board and a case main body.
　以下，本発明を具体化した最良の形態について，添付図面を参照しつつ詳細に説明する。本形態は，扁平で角形の密閉型電池に本発明を適用したものである。 Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a flat and square sealed battery.
　本形態の密閉型電池１０は，図１に示すように，扁平な直方体形の電池ケース１１を有するものである。電池ケース１１は，略板状の封口板１２を，図中上部が開口した有底箱型のケース本体１３の開口部に接合したものである。さらに，本形態の密閉型電池１０では，封口板１２の図中上部に，それぞれ外部電極端子である正極端子１４と負極端子１５とが突出して取り付けられている。 The sealed battery 10 of this embodiment has a flat rectangular battery case 11 as shown in FIG. The battery case 11 is obtained by joining a substantially plate-shaped sealing plate 12 to an opening of a bottomed box-shaped case main body 13 having an upper portion opened in the drawing. Furthermore, in the sealed battery 10 of this embodiment, a positive electrode terminal 14 and a negative electrode terminal 15 that are external electrode terminals are attached to the upper portion of the sealing plate 12 in the figure.
　さらに，電池ケース１１の内部には，電極体群１６が封入されている。この電極体群１６は，正負の電極体と電解液とを含むものである。そして，正極端子１４と負極端子１５とは，電池ケース１１の内部において電極体群１６の各電極に，それぞれ接続されている。また，封口板１２のうち正極端子１４と負極端子１５との間の位置には，安全弁１８と注液口１９とが形成されている。さらに，本形態の封口板１２には，図１に示すように，その長辺側の周縁部に沿って両側に，溝２１，２１が形成されている。この溝２１は，ほぼ均一の深さで封口板１２の縁辺に平行な直線状に形成されている。この溝２１は，封口板１２の中央側（縁辺から遠い側）に隣接した箇所の板厚より薄肉に形成されている箇所である。 Furthermore, an electrode assembly 16 is enclosed inside the battery case 11. The electrode body group 16 includes positive and negative electrode bodies and an electrolytic solution. The positive electrode terminal 14 and the negative electrode terminal 15 are connected to the respective electrodes of the electrode assembly 16 inside the battery case 11. A safety valve 18 and a liquid injection port 19 are formed at a position between the positive electrode terminal 14 and the negative electrode terminal 15 in the sealing plate 12. Further, as shown in FIG. 1, grooves 21 and 21 are formed on both sides of the sealing plate 12 of this embodiment along the peripheral portion on the long side. The groove 21 has a substantially uniform depth and is formed in a straight line parallel to the edge of the sealing plate 12. The groove 21 is a portion formed thinner than the thickness of the portion adjacent to the center side (the side far from the edge) of the sealing plate 12.
　本形態では，図２にその断面を示すように，封口板１２とケース本体１３との間に溶接部３１が形成されている。図２は，図１のＡ－Ａ端面のうち上部の封口板１２付近のみを示した図である。本形態の封口板１２の下面における周縁部の全周には，ケース本体１３の板厚ｔに対応する切り欠き３２が形成されている。そして，ケース本体１３が切り欠き３２にはめ込まれるように，ケース本体１３と封口板１２とがかさね合わせられている。これによって，封口板１２の縁辺とケース本体１３の外周面とがほぼ同一面上となるように位置合わせされている。 In this embodiment, as shown in FIG. 2, a welded portion 31 is formed between the sealing plate 12 and the case body 13. FIG. 2 is a view showing only the vicinity of the upper sealing plate 12 in the AA end face of FIG. A notch 32 corresponding to the plate thickness t of the case body 13 is formed on the entire periphery of the peripheral edge portion of the lower surface of the sealing plate 12 of this embodiment. The case main body 13 and the sealing plate 12 are overlapped so that the case main body 13 is fitted in the notch 32. Thereby, the edge of the sealing plate 12 and the outer peripheral surface of the case body 13 are aligned so as to be substantially on the same plane.
　さらに本形態では，上記のように位置合わせされて重ねられた面に対して，外側から溶接されることによって接合されている。すなわち，ケース本体１３の図２中で上端面と封口板１２の切り欠き３２との合わせ目に対して，外側からほぼ水平方向にレーザが照射される。これによって，この箇所が溶接されている。その結果，封口板１２とケース本体１３との境目には，溶接部３１が形成されている。この溶接部３１は，溶接工程において一旦溶融され，その後に凝固した範囲である。溶接部３１は，この図中では，略半円ないし半楕円形状である。 Furthermore, in this embodiment, the surfaces aligned and overlapped as described above are joined by welding from the outside. That is, the laser is irradiated from the outside in a substantially horizontal direction to the joint between the upper end surface of the case body 13 and the notch 32 of the sealing plate 12 in FIG. As a result, this point is welded. As a result, a welded portion 31 is formed at the boundary between the sealing plate 12 and the case body 13. The welded portion 31 is a range that is once melted in the welding process and then solidified. The welded portion 31 has a substantially semicircular or semielliptical shape in this figure.
　なお，図２中で奥行き方向であり，密閉型電池１０の外周面に沿った方向へは，位置を少しずつずらしてレーザ照射することにより封止されている。すなわち，各レーザ照射による溶融範囲が互いに重なる程度に隣接した位置に，複数箇所に照射する。これにより，封口板１２とケース本体１３とは隙間無く封止されている。この結果，電池ケース１１の内部が密閉されている。 In addition, in the depth direction in FIG. 2, the direction along the outer peripheral surface of the sealed battery 10 is sealed by irradiating laser with the position being shifted little by little. That is, a plurality of locations are irradiated at positions adjacent to each other so that the melting ranges of the respective laser irradiations overlap each other. Thereby, the sealing plate 12 and the case main body 13 are sealed without a gap. As a result, the inside of the battery case 11 is sealed.
　このようにされているので，溶接部３１の図２中での左右方向の幅（溶接深さ）は，場所によって多少異なる。ただし，溶接によって溶融した範囲がケース本体１３の板厚ｔより深くまで及んでいたとしても，実質的に接合に寄与しているのは高々板厚ｔの範囲までである。これは，内圧が上昇して電池ケース１１がふくらむ場合，この接合箇所では，切り欠き３２とケース本体１３との間の隙間を広げるような力を受けることとなるからである。そこで，本形態では，接合に係る溶接深さに相当するパラメータとして，ケース本体１３の板厚ｔを使用する。 Since this is done, the width (welding depth) in the left-right direction in FIG. 2 of the welded portion 31 differs somewhat depending on the location. However, even if the range melted by welding extends deeper than the plate thickness t of the case body 13, it is at most the range of the plate thickness t that contributes substantially to the joining. This is because, when the internal pressure rises and the battery case 11 swells, a force that widens the gap between the notch 32 and the case main body 13 is received at this joint location. Therefore, in this embodiment, the plate thickness t of the case body 13 is used as a parameter corresponding to the welding depth related to joining.
　一旦溶融されて凝固した範囲である溶接部３１は，ケース本体１３の他の部分に比較して，曲げなどの機械的変形に対する強度がやや小さい。そのため，内圧の変化による電池ケース１１の変形に伴う応力がこの箇所に集中することは好ましくない。そこで，本形態の密閉型電池１０では，電池ケース１１の変形に伴う応力を溶接部３１に代わって受けるために，意図的に強度を低下させた箇所を形成している。これにより，例えば冷熱サイクルによって，電池ケース１１の機械的変形が繰り返された場合でも，溶接部３１が破壊されることを防止している。 The welded portion 31 that is once melted and solidified is slightly less resistant to mechanical deformation such as bending than the other portions of the case body 13. For this reason, it is not preferable that the stress accompanying the deformation of the battery case 11 due to the change of the internal pressure is concentrated at this location. Therefore, in the sealed battery 10 of the present embodiment, in order to receive the stress accompanying the deformation of the battery case 11 instead of the welded portion 31, a portion where the strength is intentionally reduced is formed. Thereby, even when the mechanical deformation of the battery case 11 is repeated by, for example, a cooling / heating cycle, the welded portion 31 is prevented from being broken.
　すなわち，本形態の電池ケース１１の封口板１２には，溶接部３１に沿って溝２１が形成されているので，電池ケース１１が変形した場合の応力は，溶接部３１と溝２１とに分散される。この溝２１は，対応する箇所の溶接部３１とほぼ同等の強度であることが望ましい。つまり，溶接部３１とほぼ同じくらい強度の小さい箇所を，溶接部３１の近傍にあらかじめ形成しておくことにより，溶接部３１への応力の集中が抑制されているのである。このようにすることにより，密閉型電池１０の破壊に至るまでの冷熱サイクル回数は，従来のものの２倍程度に延びている。 That is, since the groove 21 is formed along the welded portion 31 in the sealing plate 12 of the battery case 11 of this embodiment, the stress when the battery case 11 is deformed is distributed to the welded portion 31 and the groove 21. Is done. It is desirable that the groove 21 has substantially the same strength as the corresponding welded portion 31. That is, the concentration of stress on the welded portion 31 is suppressed by previously forming a portion having a strength almost as small as the welded portion 31 in the vicinity of the welded portion 31. By doing in this way, the frequency | count of the thermal cycle until destruction of the sealed battery 10 is extended about twice the conventional one.
　なお，本形態の密閉型電池１０では，内圧の上昇及び下降に伴い，電池ケース１１のうち最も大面積の面（図１の右手前面及び左奥面）が最も大きく変形する。特にその中央部での変形量が大きい。そのため，溶接部３１のうち，封口板１２の長辺の中央部分に最も応力が集中する。従って，溝２１は，封口板１２の長辺について，中央近傍に設けることが好ましい。短辺側や角部には必ずしも必要ではない。ただし，安全弁１８や注液口１９の配置されている箇所の近くは避けて設けるようにしても良い。 In the sealed battery 10 of the present embodiment, the largest surface of the battery case 11 (the right front surface and the left back surface in FIG. 1) is most deformed as the internal pressure increases and decreases. In particular, the amount of deformation at the center is large. Therefore, the stress is concentrated most in the central portion of the long side of the sealing plate 12 in the welded portion 31. Therefore, the groove 21 is preferably provided near the center with respect to the long side of the sealing plate 12. It is not always necessary for the short side or the corner. However, it may be provided to avoid the vicinity of the place where the safety valve 18 and the liquid injection port 19 are arranged.
　次に，図３を参照して，溝２１の配置や大きさについて説明する。図３は，封口板１２とケース本体１３との合わせ目の断面を簡略化して図示したものである。この図では，溶接部３１は示していない。この図中の符号を用いると，溝２１の配置の条件は以下の通りである。
　ｔ／２　＜　ａ　＜　ｔ
　ｔ／２　＜　ｂ　＜　ｔ
　ｃ（＝ｔ＋ａ）　≦　Ｗ／５
ただし，ａは，ケース本体１３の内面２５から溝２１の外周側の壁面２６までの距離であり，ｂは，溝２１の底の箇所（最も薄い箇所）における封口板１２の厚さである。また，ｔは，ケース本体１３の板厚であり，Ｗは，封口板１２の短辺側の幅（図２参照）である。 Next, the arrangement and size of the grooves 21 will be described with reference to FIG. FIG. 3 shows a simplified cross section of the joint between the sealing plate 12 and the case body 13. In this figure, the welded portion 31 is not shown. Using the reference numerals in this figure, the conditions for the arrangement of the grooves 21 are as follows.
t / 2 <a <t
t / 2 <b <t
c (= t + a) ≦ W / 5
However, a is the distance from the inner surface 25 of the case body 13 to the wall surface 26 on the outer peripheral side of the groove 21, and b is the thickness of the sealing plate 12 at the bottom portion (the thinnest portion) of the groove 21. Further, t is the plate thickness of the case body 13, and W is the short side width of the sealing plate 12 (see FIG. 2).
　すなわち，ケース本体１３の内面２５から溝２１の外周側の壁面２６までの距離ａは，ケース本体１３の板厚ｔの２分の１より大きく，板厚ｔより小さい。壁面２６がケース本体１３に近すぎても遠すぎても効果が小さいからである。なお，ケース本体１３の板厚ｔは，少なくとも封口板１２との接合箇所ではどこでもほぼ一律なものとなっている。なお，溝２１の溝幅は，安全弁１８や注液口１９より外側の箇所に収まる範囲内のものであればよい。ここでは，板厚ｔの半分程度としている。 That is, the distance a from the inner surface 25 of the case body 13 to the wall surface 26 on the outer peripheral side of the groove 21 is greater than half the plate thickness t of the case body 13 and smaller than the plate thickness t. This is because the effect is small even if the wall surface 26 is too close or too far from the case body 13. The plate thickness t of the case main body 13 is almost uniform everywhere at least at the junction with the sealing plate 12. In addition, the groove width of the groove | channel 21 should just be in the range settled in the location outside the safety valve 18 or the liquid injection port 19. Here, it is about half of the plate thickness t.
　また，溝２１における厚さｂは，ケース本体１３の板厚ｔの２分の１より大きく，板厚ｔの２分の３より小さい。さらに，この厚さｂは，封口板１２における溝２１に隣接して内周側に位置する箇所の厚さｄより小さい。また，溝２１の外周側の壁面２６と，封口板１２の縁辺との距離ｃは，封口板１２の短辺側の幅Ｗ（図２参照）の５分の１以下であることが望ましい。なお，溝２１の配置については，距離ａの範囲と厚さｂの範囲のうち一方のみを満たしているものであってもよい。 Further, the thickness b in the groove 21 is larger than a half of the plate thickness t of the case main body 13 and smaller than a half of the plate thickness t. Further, the thickness b is smaller than the thickness d of the portion located on the inner peripheral side adjacent to the groove 21 in the sealing plate 12. In addition, the distance c between the wall surface 26 on the outer peripheral side of the groove 21 and the edge of the sealing plate 12 is preferably 1/5 or less of the width W (see FIG. 2) on the short side of the sealing plate 12. In addition, about arrangement | positioning of the groove | channel 21, you may satisfy | fill only one among the range of distance a and the range of thickness b.
　さらに，図１のように見ると，溝２１は封口板１２の両側の長辺に沿って，それぞれ同様の形状に形成されている。そして，その長手方向の長さＬの合計２Ｌは，封口板１２の外周全周に対して，４０％以上とすることが好ましい。ただし，その配置には，長手方向の中央近傍が含まれていることが好ましい。 Further, as shown in FIG. 1, the grooves 21 are formed in the same shape along the long sides on both sides of the sealing plate 12. The total length L of the length L in the longitudinal direction is preferably 40% or more with respect to the entire outer periphery of the sealing plate 12. However, the arrangement preferably includes the vicinity of the center in the longitudinal direction.
　さらに，発明者らは，本形態の密閉型電池と，溝の形成されていない比較例とを製造し，両者を比較する実験を行った。実験としては，冷熱サイクル試験と耐圧試験とを行った。冷熱サイクル試験では，常圧のまま，電池温度を－２０～８０℃の間で繰り返し上下し，電池ケース１１が破壊されるまでのサイクル回数を調べた。耐圧試験では，ケース本体１３のうち接合部とは遠い箇所に貫通穴を形成して，内部へガスを注入することにより内圧を上げていき，電池ケース１１が破壊されたときの内圧を測定した。なお，この実験では，安全弁及び注液口の形成されていない封口板を用いた。 Furthermore, the inventors manufactured a sealed battery of this embodiment and a comparative example in which no groove was formed, and conducted an experiment to compare the two. As an experiment, a cold cycle test and a pressure resistance test were conducted. In the thermal cycle test, the battery temperature was repeatedly raised and lowered between −20 ° C. and 80 ° C. with normal pressure, and the number of cycles until the battery case 11 was destroyed was examined. In the pressure resistance test, a through hole was formed at a location far from the joint in the case body 13, the internal pressure was increased by injecting gas into the inside, and the internal pressure when the battery case 11 was destroyed was measured. . In this experiment, a sealing plate without a safety valve and a liquid inlet was used.
　この実験では，封口板１２として，幅Ｗ（電池の厚さに相当する）が約２０ｍｍであり，長辺の長さが約１１０ｍｍのものを用いた。また，ケース本体１３の板厚ｔが１．２ｍｍの電池を用いた。さらに，上記した溝２１の配置に係る各寸法ａ，ｂ，ｃは，以下のように設定した。なお，比較例の電池は，溝２１が形成されていないだけで，それ以外は実施例のものと同じである。
　ａ　＝　１．２ｍｍ
　ｂ　＝　１．５ｍｍ
　ｃ　＝　２．０ｍｍ
　さらに，溝２１の長さ２Ｌは，封口板１２の周長の約５０％，すなわち１３０ｍｍとした。また，溝幅は０．５ｍｍとした。 In this experiment, a sealing plate 12 having a width W (corresponding to the thickness of the battery) of about 20 mm and a long side of about 110 mm was used. A battery having a case body 13 with a plate thickness t of 1.2 mm was used. Furthermore, the dimensions a, b, and c related to the arrangement of the grooves 21 described above were set as follows. The battery of the comparative example is the same as that of the example except that the groove 21 is not formed.
a = 1.2 mm
b = 1.5mm
c = 2.0 mm
Further, the length 2L of the groove 21 is about 50% of the circumferential length of the sealing plate 12, that is, 130 mm. The groove width was 0.5 mm.
　冷熱サイクル試験は，以下のような結果となった。ここでは，実施例と比較例をそれぞれ５個ずつ製造して，破壊されるまでのサイクル回数の平均値を算出した。
　サイクル回数の平均値　　実施例　　２１５３回
　　　　　　　　　　　　　比較例　　１２５３回
であった。この結果から，本実施例では，比較例に比較して耐久性能が非常に高くなったことが確認できた。 The results of the thermal cycle test were as follows. Here, five examples and comparative examples were manufactured, and the average number of cycles until destruction was calculated.
Average value of the number of cycles Example 2153 times Comparative Example 1253 times. From this result, it was confirmed that in this example, the durability performance was very high as compared with the comparative example.
Figure JPOXMLDOC01-appb-T000001
   
Figure JPOXMLDOC01-appb-T000001
   
　耐圧試験の結果を，表１に示す。ここでは，実施例と比較例とについてそれぞれ５個のサンプルを製造して実験を行った。そして，内圧の上昇により最初に破壊された場所と，そのときの圧力とについてそれぞれ示した。この表に示すように，実施例ではいずれも，まず封口板が破壊された。すなわち，封口板に形成した溝によって，溶接部が保護されていることが確認できた。 Table 1 shows the results of the pressure test. Here, five samples for each of the example and the comparative example were manufactured and tested. And the place where it was first destroyed by the rise of internal pressure and the pressure at that time are shown respectively. As shown in this table, in all the examples, the sealing plate was first destroyed. In other words, it was confirmed that the weld was protected by the groove formed in the sealing plate.
　なお，表１に示すように，実施例の耐圧圧力は，いずれも，比較例のものに比較してやや小さいものであった。しかし，実際の密閉型電池には安全弁が形成されているので，実際の使用環境においては，密閉型電池の内圧がこの耐圧試験での破壊圧力ほどまで上昇するようなことはない。よって，この程度の耐圧性能を有すれば充分である。実際の使用において重要なのは，耐圧が特に大きいことよりもむしろ，温度変化等による繰り返しの圧力変化に対する耐久性が大きいことである。すなわち，耐圧試験の結果よりもサイクル試験の結果が重要なのである。上記の実験結果からも，本実施例の電池は，比較例のものに比較して長寿命であることが確認できた。 In addition, as shown in Table 1, all of the withstand pressures of the examples were slightly smaller than those of the comparative examples. However, since a safety valve is formed in an actual sealed battery, the internal pressure of the sealed battery does not increase as much as the breakdown pressure in this pressure test in the actual usage environment. Therefore, it is sufficient to have such a pressure resistance performance. What is important in actual use is that the durability against repeated pressure changes due to temperature changes is great, rather than having a particularly high pressure resistance. In other words, the result of the cycle test is more important than the result of the pressure test. From the above experimental results, it was confirmed that the battery of this example had a longer life than that of the comparative example.
　以上詳細に説明したように，本形態の密閉型電池１０によれば，例えば充放電によるガスの発生等により，内部の圧力が上下する。特に，内圧上昇時には，ケース本体１３がふくらみ，ケース本体１３と封口板１２との間の溶接部３１に，開く向きの力が加わる。このとき，本形態では，封口板１２に溝２１が形成されているので，溶接部３１と溝２１とに応力が分散される。従って，溶接部３１のみに応力が集中するものに比較して，変形が繰り返されても破壊には至りにくい。これにより，内圧の変化等による電池ケースの変形が繰り返されても，溶接部にクラックや疲労破壊が発生しにくく，長期間にわたって良好な密閉性を維持できる密閉型電池となっている。 As described in detail above, according to the sealed battery 10 of this embodiment, the internal pressure increases and decreases due to, for example, the generation of gas due to charging and discharging. In particular, when the internal pressure rises, the case main body 13 swells, and an opening force is applied to the welded portion 31 between the case main body 13 and the sealing plate 12. At this time, in this embodiment, since the groove 21 is formed in the sealing plate 12, the stress is distributed between the welded portion 31 and the groove 21. Therefore, as compared with the case where the stress is concentrated only on the welded portion 31, even if the deformation is repeated, it is less likely to break. As a result, even when the battery case is repeatedly deformed due to changes in internal pressure or the like, the sealed battery is less susceptible to cracking or fatigue failure in the welded portion and can maintain good hermeticity over a long period of time.
　なお，封口板１２に溝２１を形成する代わりに，図４に示すように，ケース本体４３に溝４４を形成したものでも同様の効果が得られる。この密閉型電池４０の電池ケース４１は，溝の形成されていない封口板４２と溝４４を有するケース本体４３とが，接合されたものである。溝４４は，封口板４２とケース本体４３との合わせ目に沿って，ケース本体４３の図中上端近くに形成されている。このようなものであっても図１の例と同様に，溶接部への応力を分散し，耐久性の高い密閉型電池とすることができる。 It should be noted that, instead of forming the groove 21 in the sealing plate 12, the same effect can be obtained even when the groove 44 is formed in the case main body 43 as shown in FIG. The battery case 41 of the sealed battery 40 is formed by joining a sealing plate 42 having no groove and a case body 43 having a groove 44. The groove 44 is formed near the upper end of the case body 43 in the drawing along the joint between the sealing plate 42 and the case body 43. Even in such a case, similar to the example of FIG. 1, the stress to the welded portion is dispersed, and a highly durable sealed battery can be obtained.
　このタイプの密閉型電池４０について，その封口板４２とケース本体４３との合わせ目の断面を簡略化して，図５に示す。この例における溝４４の配置は，図中の各符号を用いて，以下に示す通りとすることが望ましい。溝４４以外の箇所におけるケース本体４３の板厚ｔと，封口板４２の幅Ｗは，図１に示した形態と同様のものである。 FIG. 5 shows a simplified section of the joint between the sealing plate 42 and the case main body 43 of the sealed battery 40 of this type. The arrangement of the grooves 44 in this example is preferably as shown below using the reference numerals in the figure. The thickness t of the case main body 43 and the width W of the sealing plate 42 at locations other than the grooves 44 are the same as those shown in FIG.
　ｔ／２　＜　ｆ　＜　ｔ
　ｇ　＜　Ｗ／５
　ｔ／２　＜　ｈ　＜　ｔ
　ただし，ｆは，溝４４の箇所におけるケース本体４３の板厚であり，ｇは，封口板４２の上面からの溝４４の上端までの距離であり，ｈは，封口板４２の下面（外からは見えない）から溝４４の上端までの距離である。さらに，溝４４の合計の長さは，封口板４２の全周に対して，４０％以上とすることが好ましい。 t / 2 <f <t
g <W / 5
t / 2 <h <t
Where f is the thickness of the case body 43 at the groove 44, g is the distance from the upper surface of the sealing plate 42 to the upper end of the groove 44, and h is the lower surface of the sealing plate 42 (from the outside). Is the distance from the upper end of the groove 44 to the upper end of the groove 44. Furthermore, the total length of the grooves 44 is preferably 40% or more with respect to the entire circumference of the sealing plate 42.
　なお，本形態は単なる例示にすぎず，本発明を何ら限定するものではない。したがって本発明は当然に，その要旨を逸脱しない範囲内で種々の改良，変形が可能である。
　例えば，上記の例では角溝を図示しているが，溝の断面形状はこれに限らず，三角溝，丸溝等とすることもできる。また例えば，上記の形態では，封口板の長辺に沿って，それぞれ１つの溝としたが，例えば図６に示すように，いくつかに分断された溝５１を形成してもよい。また，本形態ではいずれも均一な深さの溝としたが，場所によって深さの異なるものとしてもよい。例えば，中央に近いほど深い溝としてもよい。 In addition, this form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
For example, although a square groove is illustrated in the above example, the cross-sectional shape of the groove is not limited to this, and may be a triangular groove, a round groove, or the like. Further, for example, in the above embodiment, one groove is formed along the long side of the sealing plate. However, as shown in FIG. 6, for example, a plurality of grooves 51 may be formed. In this embodiment, the grooves have a uniform depth, but the depth may be different depending on the location. For example, a deeper groove closer to the center may be used.
　さらに，例えば図７や図８に示すように，封口板１２，４２とケース本体１３，４３との溶接面が，ケース本体１３，４３の側面にそれぞれ平行な面である密閉型電池にも適用可能である。この場合にも，封口板１２，４２またはケース本体１３，４３として，上記の形態と同様に，その溶接部近傍に溝２１，４４を設けたものとすればよい。また，電池ケースの形状は，扁平角形に限らず，円筒形等のものにも適用可能である。 Further, for example, as shown in FIGS. 7 and 8, the present invention is also applied to a sealed battery in which the welding surfaces of the sealing plates 12 and 42 and the case main bodies 13 and 43 are parallel to the side surfaces of the case main bodies 13 and 43, respectively. Is possible. Also in this case, as the sealing plates 12 and 42 or the case main bodies 13 and 43, the grooves 21 and 44 may be provided in the vicinity of the welded portions in the same manner as in the above embodiment. Further, the shape of the battery case is not limited to a flat rectangular shape, but can be applied to a cylindrical shape or the like.
　１０，４０　密閉型電池
　１１　電池ケース
　１２，４２　封口板
　１３，４３　ケース本体
　１６　電極体群
　２１，４４　溝
　３１　溶接部 10, 40 Sealed battery 11 Battery case 12, 42 Sealing plate 13, 43 Case body 16 Electrode body group 21, 44 Groove 31 Welded portion

Claims (7)

  1. 一面が開口部となっているケース本体と，前記ケース本体の開口部を塞ぐ封口部材とを有し，前記ケース本体に発電要素を収納して封口されている密閉型電池において，
    　前記ケース本体の開口部と前記封口部材との接合箇所が，全周にわたって溶接されているものであり，
    　前記封口部材または前記ケース本体は，
    　　前記接合箇所以外の箇所に，前記接合箇所に沿った薄肉部が形成されているとともに，
    　　前記薄肉部に隣接して前記接合箇所から遠い側に位置する箇所の厚さが，前記薄肉部より厚いものであることを特徴とする密閉型電池。     In a sealed battery having a case body having an opening on one side and a sealing member that closes the opening of the case body, the power generation element is housed and sealed in the case body,
    The joint portion between the opening of the case body and the sealing member is welded over the entire circumference,
    The sealing member or the case body is
    A thin wall portion is formed along the joining portion at a place other than the joining place,
    A sealed battery characterized in that a thickness of a portion located adjacent to the thin portion and on a side far from the joint portion is thicker than the thin portion.
  2. 請求項１に記載の密閉型電池において，
    　前記薄肉部が，前記封口部材に形成されている溝であることを特徴とする密閉型電池。     The sealed battery according to claim 1,
    The sealed battery, wherein the thin portion is a groove formed in the sealing member.
  3. 請求項２に記載の密閉型電池において，
    　前記薄肉部における前記封口部材の厚さは，前記ケース本体の板厚の０．５～１．５倍の範囲内であることを特徴とする密閉型電池。     The sealed battery according to claim 2,
    The sealed battery according to claim 1, wherein a thickness of the sealing member in the thin wall portion is in a range of 0.5 to 1.5 times a plate thickness of the case body.
  4. 請求項２または請求項３に記載の密閉型電池において，
    　前記溝における前記封口部材の縁辺側の壁面は，前記封口部材の縁辺から，前記ケース本体の板厚の１．５～２倍の範囲内の距離の位置に形成されていることを特徴とする密閉型電池。     The sealed battery according to claim 2 or 3,
    The wall surface on the edge side of the sealing member in the groove is formed at a position within a range of 1.5 to 2 times the plate thickness of the case body from the edge of the sealing member. Sealed battery.
  5. 請求項２から請求項４までのいずれか１つに記載の密閉型電池において，
    　前記溝の長さの合計は，前記接合箇所の全長の４０％以上であることを特徴とする密閉型電池。     In the sealed battery according to any one of claims 2 to 4,
    The sealed battery characterized in that the total length of the grooves is 40% or more of the total length of the joints.
  6. 請求項２から請求項５までのいずれか１つに記載の密閉型電池において，
    　前記ケース本体が扁平角形のものであって，
    　前記溝は，
    　　前記封口部材の外面に，少なくとも長辺方向の中央位置を含んで，両長辺に沿ってそれぞれ同じ長さで，形成されているものであり，
    　　前記封口部材の縁辺から，前記封口部材の短辺の長さの２０％以下の位置に形成されているものであることを特徴とする密閉型電池。     In the sealed battery according to any one of claims 2 to 5,
    The case body has a flat rectangular shape,
    The groove is
    The outer surface of the sealing member includes at least a central position in the long side direction and is formed with the same length along both long sides,
    A sealed battery, wherein the battery is formed at a position that is 20% or less of a length of a short side of the sealing member from an edge of the sealing member.
  7. 一面が開口部となっているケース本体と，前記ケース本体の開口部を塞ぐ封口部材とを有する電池ケースにおいて，
    　前記ケース本体の開口部と前記封口部材との接合箇所が，全周にわたって溶接されるものであり，
    　前記封口部材または前記ケース本体は，
    　　前記接合箇所以外の箇所に，前記接合箇所に沿った薄肉部が形成されているとともに，
    　　前記薄肉部に隣接して前記接合箇所から遠い側に位置する箇所の厚さが，前記薄肉部より厚いものであることを特徴とする電池ケース。
          In a battery case having a case body having an opening on one side and a sealing member for closing the opening of the case body,
    The joint portion between the opening of the case body and the sealing member is welded over the entire circumference,
    The sealing member or the case body is
    A thin wall portion is formed along the joining portion at a place other than the joining place,
    A battery case characterized in that a thickness of a portion located adjacent to the thin portion on the side far from the joint portion is thicker than the thin portion.
PCT/JP2009/061161 2009-06-19 2009-06-19 Sealed battery and battery case for the same WO2010146700A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2009/061161 WO2010146700A1 (en) 2009-06-19 2009-06-19 Sealed battery and battery case for the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2009/061161 WO2010146700A1 (en) 2009-06-19 2009-06-19 Sealed battery and battery case for the same

Publications (1)

Publication Number Publication Date
WO2010146700A1 true WO2010146700A1 (en) 2010-12-23

Family

ID=43356038

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/061161 WO2010146700A1 (en) 2009-06-19 2009-06-19 Sealed battery and battery case for the same

Country Status (1)

Country Link
WO (1) WO2010146700A1 (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012105364A1 (en) * 2011-01-31 2012-08-09 三洋電機株式会社 Prismatic sealed cell
JP2013054964A (en) * 2011-09-05 2013-03-21 Toyota Motor Corp Sealed battery
JP2014041770A (en) * 2012-08-22 2014-03-06 Toyota Motor Corp Battery
WO2014033906A1 (en) * 2012-08-31 2014-03-06 日立ビークルエナジー株式会社 Rectangular secondary battery
JP2014057986A (en) * 2012-09-18 2014-04-03 Toyota Motor Corp Laser welding method
JP2014103125A (en) * 2014-02-05 2014-06-05 Hitachi Vehicle Energy Ltd Square secondary battery
WO2015072010A1 (en) * 2013-11-15 2015-05-21 日立オートモティブシステムズ株式会社 Prismatic battery
JP2015133300A (en) * 2014-01-15 2015-07-23 株式会社豊田自動織機 power storage device
DE102015110244A1 (en) * 2015-06-25 2016-12-29 Schuler Pressen Gmbh Battery cell housing and method for its manufacture
DE112016005140B4 (en) * 2015-11-09 2019-10-02 Kabushiki Kaisha Toyota Jidoshokki Electric storage device
JPWO2019116914A1 (en) * 2017-12-12 2020-12-17 株式会社Ｇｓユアサ Power storage element

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0587814U (en) * 1992-04-28 1993-11-26 日本電池株式会社 Square sealed battery
JPH11297292A (en) * 1998-04-08 1999-10-29 Alps Electric Co Ltd Hermetic device with safety valve
JP2000268781A (en) * 1999-03-17 2000-09-29 Sanyo Electric Co Ltd Sealing plate for sealed battery, sealed battery and manufacture thereof
JP2006260883A (en) * 2005-03-16 2006-09-28 Toyota Motor Corp Sealed electricity storage and manufacturing method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0587814U (en) * 1992-04-28 1993-11-26 日本電池株式会社 Square sealed battery
JPH11297292A (en) * 1998-04-08 1999-10-29 Alps Electric Co Ltd Hermetic device with safety valve
JP2000268781A (en) * 1999-03-17 2000-09-29 Sanyo Electric Co Ltd Sealing plate for sealed battery, sealed battery and manufacture thereof
JP2006260883A (en) * 2005-03-16 2006-09-28 Toyota Motor Corp Sealed electricity storage and manufacturing method thereof

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012105364A1 (en) * 2011-01-31 2012-08-09 三洋電機株式会社 Prismatic sealed cell
JP2013054964A (en) * 2011-09-05 2013-03-21 Toyota Motor Corp Sealed battery
JP2014041770A (en) * 2012-08-22 2014-03-06 Toyota Motor Corp Battery
US9812676B2 (en) 2012-08-31 2017-11-07 Hitachi Automotive Systems, Ltd. Prismatic secondary battery
WO2014033906A1 (en) * 2012-08-31 2014-03-06 日立ビークルエナジー株式会社 Rectangular secondary battery
JP5475206B1 (en) * 2012-08-31 2014-04-16 日立ビークルエナジー株式会社 Prismatic secondary battery
JP2014057986A (en) * 2012-09-18 2014-04-03 Toyota Motor Corp Laser welding method
US9905819B2 (en) 2013-11-15 2018-02-27 Hitachi Automotive Systems, Ltd. Prismatic battery
JPWO2015072010A1 (en) * 2013-11-15 2017-03-09 日立オートモティブシステムズ株式会社 Square battery
WO2015072010A1 (en) * 2013-11-15 2015-05-21 日立オートモティブシステムズ株式会社 Prismatic battery
JP2015133300A (en) * 2014-01-15 2015-07-23 株式会社豊田自動織機 power storage device
JP2014103125A (en) * 2014-02-05 2014-06-05 Hitachi Vehicle Energy Ltd Square secondary battery
DE102015110244A1 (en) * 2015-06-25 2016-12-29 Schuler Pressen Gmbh Battery cell housing and method for its manufacture
US10673026B2 (en) 2015-06-25 2020-06-02 Schuler Pressen Gmbh Battery cell housing and method for producing same
DE102015110244B4 (en) 2015-06-25 2023-01-19 Schuler Pressen Gmbh Battery cell housing and method of manufacturing same
DE112016005140B4 (en) * 2015-11-09 2019-10-02 Kabushiki Kaisha Toyota Jidoshokki Electric storage device
JPWO2019116914A1 (en) * 2017-12-12 2020-12-17 株式会社Ｇｓユアサ Power storage element
JP7247893B2 (en) 2017-12-12 2023-03-29 株式会社Ｇｓユアサ Storage element
US11640880B2 (en) 2017-12-12 2023-05-02 Gs Yuasa International Ltd. Energy storage device

Similar Documents

Publication Publication Date Title
WO2010146700A1 (en) Sealed battery and battery case for the same
TWI239111B (en) Sealed battery
TWI690109B (en) Sealing plate
JP4493623B2 (en) Secondary battery
KR100458437B1 (en) Sealed battery
US9496538B2 (en) Battery, production method for battery, and mask member for production of battery
JP4715843B2 (en) Sealed battery
JP4865254B2 (en) Nonaqueous electrolyte secondary battery
JP2008541373A (en) Lithium secondary battery with improved tab bondability to polymer film
JP2010021027A (en) Sealed battery
JP2006216411A (en) Sealed battery
JP6085058B1 (en) Battery can and battery
US20240021936A1 (en) Battery housing, battery, and electronic device
JP6548031B2 (en) Method of manufacturing sealed battery
JP5110958B2 (en) Sealed battery
US9029007B2 (en) Rechargeable battery including first and second metallic plates coupled together and a cap assembly including an insulator
JP6872145B2 (en) Terminal fixing structure
JP2016110859A (en) Current cutoff device and secondary battery
JP6523722B2 (en) Sealing plate of cylindrical battery and cylindrical battery
WO2024001498A1 (en) Battery
JP5162106B2 (en) Battery with pressure relief valve
JP6608787B2 (en) Manufacturing method of sealed battery
US20130255073A1 (en) Method for manufacturing sealed cell
WO2021124796A1 (en) Non-aqueous electrolyte secondary battery
JP6761961B2 (en) Lithium primary battery

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09846193

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09846193

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP