WO2014141765A1 - Assembled battery - Google Patents

Assembled battery Download PDF

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Publication number
WO2014141765A1
WO2014141765A1 PCT/JP2014/052194 JP2014052194W WO2014141765A1 WO 2014141765 A1 WO2014141765 A1 WO 2014141765A1 JP 2014052194 W JP2014052194 W JP 2014052194W WO 2014141765 A1 WO2014141765 A1 WO 2014141765A1
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WO
WIPO (PCT)
Prior art keywords
assembled battery
insulating film
battery
spacer
exterior insulating
Prior art date
Application number
PCT/JP2014/052194
Other languages
French (fr)
Japanese (ja)
Inventor
吉田　正
Original Assignee
日立オートモティブシステムズ株式会社
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Application filed by 日立オートモティブシステムズ株式会社 filed Critical 日立オートモティブシステムズ株式会社
Publication of WO2014141765A1 publication Critical patent/WO2014141765A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0413—Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0481—Compression means other than compression means for stacks of electrodes and separators
    • 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
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
    • H01M50/207—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape
    • H01M50/209—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape adapted for prismatic or rectangular cells
    • 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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/289—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by spacing elements or positioning means within frames, racks or packs
    • H01M50/291—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by spacing elements or positioning means within frames, racks or packs characterised by their shape
    • 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 an assembled battery using a secondary battery such as a lithium ion secondary battery.
  • the lithium ion secondary battery In the reaction of the lithium ion secondary battery, the lithium ion secondary battery swells by being inserted into the negative electrode during charging. If this state is left as it is, it will lead to deterioration of the lithium ion secondary battery and reduce the life of the lithium ion secondary battery. Therefore, it is necessary to tie up lithium ion secondary batteries and suppress swelling.
  • lithium ion secondary batteries have a structure that insulates the outer periphery of the battery can in order to increase safety.
  • a power storage device using a metal case includes a resin frame directly fixed to a part of the outer surface of the metal case, and at least an exposed metal surface on the outer surface of the metal case where the resin frame is not fixed is insulated.
  • a secondary battery covered with a film is known (see Patent Document 1).
  • a graphite-based active material may be used for the negative electrode.
  • the dimensional change ratio of the graphite-based active material is as large as about 10% between full charge and complete discharge. If the expansion and contraction associated with charging / discharging is allowed as it is, the performance of the battery is greatly reduced. However, if the battery is restrained from the outside, the performance deterioration can be greatly suppressed. Hereinafter, restraining the battery from the outside is referred to as lashing.
  • the assembled battery according to the present invention is formed by laminating a plurality of flat batteries having a pair of wide surfaces facing the battery container thickness direction on the surface of the battery container and the wide surfaces of adjacent flat batteries facing each other.
  • a holding member that holds a plurality of flat batteries in a state where compressive force is applied, and an exterior insulating film that covers the outer periphery of the battery container except for a part of the wide surface, the holding members face each other between adjacent flat batteries
  • a spacer that is provided between the wide surfaces and contacts the non-protected portion of the wide surface that is not covered with the exterior insulating film at the contact portion.
  • the present invention deterioration of the battery characteristics of the flat battery can be prevented, and the durability of the assembled battery can be greatly improved.
  • FIG. 1 is an exploded view showing the overall configuration of the assembled battery 100 of the present embodiment.
  • FIG. 2 is an exploded view showing a stacked state of the unit cells 10 constituting the assembled battery 100
  • FIG. 3 is an enlarged view of a part of FIG.
  • the assembled battery 100 includes a plurality of unit cells 10, a battery cell holder 40, and a fixing member 120.
  • the output of the assembled battery 100 is determined from the specifications of a mobile object such as an automobile in which the assembled battery 100 is incorporated and the power storage system, and the number of single cells 10 incorporated in the assembled battery 100 is determined.
  • the number of unit cells 10 incorporated in the assembled battery 100 is about several tens of cells.
  • a battery pack configured by incorporating a plurality of the assembled batteries 100 is mounted on a moving body such as an automobile, a power storage system, or the like.
  • the stacked body 110 in which a plurality of flat unit cells 10 are stacked has a compressive force applied to the stacking direction of the single cells 10 (hereinafter simply referred to as the stacking direction) by the fixing member 120. It is restrained (fixed) by.
  • the stacked body 110 is formed by stacking a plurality of unit cells 10 held by a battery cell holder 40.
  • restraining the stacked body 110 in a state where a compressive force is applied to each unit cell 10 in the stacking direction by the fixing member 120 is also referred to as lashing.
  • the compressive force in the stacking direction applied to each unit cell 10 by the fixing member 120 is also referred to as lashing force.
  • the fixing member includes a pair of end plates 121 and a pair of side plates 126.
  • Each of the pair of end plates 121 is a thick plate-like member that abuts the stacked body 110 in the stacking direction of the unit cells and applies a securing force to the stacked body 110.
  • a screw hole 122 into which a fastening bolt 125 for fastening to the side plate 126 is screwed is provided on a side surface extending in the thickness direction of each end plate 121.
  • the pair of side plates 126 are plate-like members that fix the pair of end plates 121 in a state in which a binding force is applied to the laminate 110 with the pair of end plates 121.
  • Each side plate 126 is provided with a plurality of openings 127 and a plurality of through holes 128.
  • the opening 127 is an opening serving as an air inlet / outlet for air-cooling the unit cell 10, and is provided at a position corresponding to a position of a side opening 43 described later.
  • the through hole 128 is a through hole through which a fastening bolt 125 for fastening the side plate 126 and the end plate 121 is inserted.
  • the battery cell holder 40 includes an intermediate holder 41 provided between two adjacent unit cells 10 and the unit cell 10 positioned on the outermost side among the stacked unit cells 10. And an end holder 46 provided on the outside.
  • the battery cell holder 40 is made of an electrically insulating resin.
  • the intermediate holder 41 is perpendicular to the narrow surface 13, which is a side surface extending in the thickness direction of the unit cell 10 to be described later, and the frame 42 that supports the bottom surface 14 of the unit cell 10, and the narrow surface 13 and the bottom surface 14. And a spacer 51 that directly contacts the wide surface 12 of the unit cell 10 to be described later.
  • the intermediate holder 41 is provided with side openings 43 on both sides serving as air inlets and outlets for air-cooling the unit cell 10.
  • the end holder 46 includes a frame 47 that supports the narrow surface 13 and the bottom surface 14 of the unit cell 10 to be described later, and a spacer 52 that directly contacts the wide surface 12 of the unit cell 10.
  • the spacer 52 is in contact with the side plate 126 on the surface facing the end holder 46.
  • a plurality of spacers 51 and spacers 52 are provided apart from each other in the vertical direction.
  • FIG. 4 is a perspective view of the unit cell 10 around which the exterior insulating film 26 is wound.
  • the unit cell 10 is a flat lithium ion secondary battery, in which a non-illustrated wound group of battery cells is accommodated in a flat bottomed rectangular tube container (battery container) 11 and an upper lid 15 is covered.
  • the upper lid 15 is provided with a battery terminal 16.
  • the battery case 11 has a wide surface 12, a narrow surface 13, and a bottom surface 14.
  • the wide surface 12 is a pair of surfaces facing the thickness direction of the battery container 11 among the side surfaces of the battery container 11.
  • the narrow surface 13 is a pair of surfaces extending in the thickness direction of the battery case 11 among the side surfaces of the battery case 11.
  • the bottom surface 14 is the bottom surface of the battery container 11.
  • an exterior insulating film 26 is wound at a plurality of locations apart in the vertical direction.
  • the exterior insulating film 26 is an insulating material for preventing an unintended electrical short circuit, and an adhesive layer (not shown) for attaching to the battery container 11 is provided on one surface.
  • the exterior insulation film 26 has a number of wrinkles, and is attached so that both ends of the strip-like exterior insulation film 26 overlap, for example, the narrow surface 13 of the battery container 11.
  • the side surface of the battery case 11 is exposed at a portion where the exterior insulating film 26 is not wound.
  • a portion around which the exterior insulating film 26 is wound is referred to as a protection portion 19, and a portion where the exterior insulation film 26 is not wound is referred to as a non-protection portion 17.
  • the exposed part on the wide surface 12 is called a spacer contact part 18.
  • FIG. 5 is a cross-sectional view schematically showing a state in which the spacer 51 of the intermediate holder 41 sandwiched between the wide surfaces 12 of the adjacent unit cells 10 contacts the spacer contact portion 18.
  • the contact state between the spacer 52 provided on the end holder 46 and the spacer contact portion 18 is the same as the contact state between the spacer 51 and the spacer contact portion 18, the illustration is omitted. .
  • each spacer 51 comes into contact with the spacer contact portion 18.
  • each spacer 52 comes into contact with the spacer contact portion 18.
  • the exterior insulating film 26 is spaced apart in the vertical direction so that the spacer 51 and the spacer 52 and the non-protecting portion 17 (that is, the exposed surface of the battery container 11) on the wide surface 12 are in direct contact with each other. It is rolled up.
  • a contact portion (contact surface) of the spacers 51 and 52 with the spacer contact portion 18 is referred to as a contact portion 54.
  • the unit cell 10 is held by the intermediate holder 41 and the end holder 46 to form a laminated body 110, and a pair of end plates 121 and a pair of side plates are applied with a compression force sandwiched between the laminated bodies 110 from the laminating direction.
  • the fastening body 126 is fastened with the fastening bolt 125
  • the laminate 110 is secured with a predetermined compressive force. That is, the end plate 121 and the spacer 52 of the end holder 46 come into contact with each other, and the lashing force is transmitted to the wide surface of the outermost unit cell 10.
  • the securing force transmitted to the outermost unit cell 10 transmits the securing force to the adjacent unit cell 10 via the spacer 51 that is in contact with the wide surfaces 12. Therefore, a securing force is applied to the wide surfaces 12 of all the cells 10 constituting the stacked body 110.
  • FIG. 6 is data showing the degree of improvement in battery characteristic deterioration caused by applying a securing force.
  • the horizontal axis represents the number of charge / discharge cycles, that is, the number of cycles
  • the vertical axis represents the capacity and the rate of change of DCR that serve as a guideline for characteristics.
  • the capacity is the amount of electricity that the battery can store, and it is desirable that the capacity does not decrease over a long period of time.
  • DCR is the electric resistance inside the battery, and it is desirable that it does not increase over a long period of time.
  • FIG. 7 is a cross-sectional view schematically showing a state in which the spacer 51 of the intermediate holder 41 sandwiched between the wide surfaces 12 of the adjacent unit cells 10 is in contact with the exterior insulating film 26 attached to the wide surface 12.
  • the exterior insulating film 26 has an adhesive layer to be attached to the battery container 11, and the film material itself needs to have flexibility in order to be wound around the battery container 11. If pressure due to the lashing force is continuously applied to such a material, the exterior insulating film 26 maintains its thickness in the initial operation state. However, during the operation over a long period of time, the exterior insulating film 26 is creep-deformed and thinned as shown in FIG. If it will be in this state, the securing force will fall and it will accelerate
  • the thickness of the exterior insulating film 26 is usually about 0.05 mm. Therefore, the total of the wide surfaces 12 on both sides of the battery container 11 is about 0.1 mm. The extent to which the securing force is released due to this thickness change will be described with reference to FIG.
  • FIG. 9 is data showing an example of a change in the thickness of the unit cell 10 when the securing force, that is, the load is increased.
  • the thickness (cell thickness) of the unit cell 10 when the load 2000 N is applied to the wide surface 12 of the unit cell 10 is 26.92 mm. This thickness is used as a design dimension when the battery pack 100 is incorporated.
  • the cell thickness at the time of charging / discharging remains fixed at the design dimension of 26.92 mm.
  • the load when SOC becomes 0% due to discharge decreases to about 1000N
  • the load when SOC reaches 100% due to charging increases to about 4000N. .
  • the cell thickness is allowed to increase by 0.1 mm, which corresponds to the thickness of the pair of wide surfaces 12 of the exterior insulating film 26, the cell thickness is 27.02 mm.
  • the spacer 51 and the non-protecting portion 17 on the wide surface 12 are in direct contact with each other, so that they are not affected by the creep deformation of the exterior insulating film 26.
  • the assembled battery 100 of the present embodiment has the following operational effects. (1) In the state where a plurality of flat unit cells 10 are stacked with the wide surfaces 12 facing each other to form a stacked body 110, and a compressive force is applied in the stacking direction of the unit cells 10 by the fixing member 120. Configured to hold. The spacer 51 is provided between the wide surfaces 12 facing each other in the adjacent unit cells 10 and is configured to directly contact the wide surface 12. Thereby, since each cell 10 can be stably secured for a long period of time, deterioration of battery characteristics can be prevented and the durability of the assembled battery 100 can be greatly improved.
  • FIG. 10 is a diagram showing the exterior insulating film 27 of the present embodiment.
  • the exterior insulating film 27 of the present embodiment has a plurality of openings 28.
  • the shape of each opening 28 and the position of each opening 28 on the exterior insulating film 27 are such that each opening 28 is positioned on the pair of wide surfaces 12 when the exterior insulating film 27 is wound around the side surface of the battery container 11. Is set to Further, the shape of each opening 28 and the position of each opening 28 on the exterior insulating film 27 are such that when the intermediate holder 41 and the end holder 42 are attached to the unit cell 10, the spacers 51, It is set so as to coincide with the position where 52 abuts.
  • the protection part 19 and the non-protection part 17 are provided on the wide surface 12 at the same position as the first embodiment, The narrow surface 13 is covered with the exterior insulating film 27 without a break.
  • the assembled battery 100 of the present embodiment has the following operational effects in addition to the operational effects of the first embodiment.
  • the exterior insulating film 27 wound around the side surface of the unit cell 10 is a single sheet, and a plurality of openings 28 are provided.
  • the shape of each opening 28 and the position of each opening 28 on the exterior insulating film 27 are such that when the intermediate holder 41 and the end holder 42 are attached to the unit cell 10, the spacer 51, It was made to correspond with the position which 52 contact
  • one exterior insulation film 27 should just be wound per cell 10, the efficiency of the process of a film and the operation
  • FIG. 12 is a cross-sectional view schematically showing a state in which the spacer 51 of the intermediate holder 41 sandwiched between the wide surfaces 12 of adjacent unit cells 10 abuts against the spacer abutting portion 18 in the present embodiment. It is.
  • each spacer 51 comes into contact with the spacer contact portion 18 at the contact portion 54.
  • the dimension of the spacer contact portion 18 in the illustrated vertical direction is slightly larger than the dimension of the spacer 51 in the illustrated vertical direction.
  • the vertical dimension of the spacer abutting portion 18 and the vertical dimension of the spacer 51 are equal.
  • the vertical dimension of the spacer abutting portion 18 is set to the upper and lower dimensions of the spacer 51 so that the spacer 51 reliably contacts the spacer abutting portion 18. It is necessary to make it larger than the dimension in the direction by the above error. Therefore, a gap 29 is formed between the spacer 51 and the exterior insulating film 26 on the upper and lower sides of the spacer 51, and the metal surface that is the surface of the battery container 11 is exposed. There is a risk of an electrical short circuit from this exposed portion.
  • the gap 29 is filled with an insulating resin 61 having electrical insulating properties so that the surface of the battery container 11 is not exposed.
  • the assembled battery 100 of the present embodiment has the following operational effects in addition to the operational effects of the first and second embodiments.
  • the vertical dimension of the spacer abutting portion 18 in the figure is made larger than the vertical dimension of the spacer 51 in the figure by the above error. Accordingly, the contact portion 54 of the spacer 51 does not press the exterior insulating film 26 in the laminating direction, so that the above-described creep deformation of the exterior insulating film 26 does not occur and the transmission of the securing force is adversely affected. Absent. Therefore, since each cell 10 can be stably secured for a long period of time, the battery characteristics can be prevented from deteriorating and the durability of the assembled battery 100 can be greatly improved.
  • FIG. 14 schematically shows the positional relationship between the spacer 53 of the intermediate holder 41 sandwiched between the wide surfaces 12 of the adjacent unit cells 10, the spacer contact portion 18, and the exterior insulating film 26 in the present embodiment.
  • FIG. 14 When the unit cell 10 is held by the intermediate holder 41, each spacer 53 comes into contact with the spacer contact portion 18 at the contact portion 54. Further, the spacer 53 of the present embodiment has an overlapping portion 55 that overlaps with the protective portion 19 covered with the exterior insulating film 26 and the exterior insulating film 26.
  • the overlapping portion 55 is a portion extending upward and downward in the drawing relative to the abutting portion 54 of the spacer 53, and the thickness in the horizontal direction in the drawing (that is, the stacking direction of the unit cells 10) is the same. It is thinner than the contact portion 54.
  • the thickness of the overlapping portion 55 in the stacking direction is set so as to be in close contact with the exterior insulating film 26 wound around the unit cell 10 when the unit cell 10 is held by the intermediate holder 41.
  • the thickness in the stacking direction of the overlapping portion 55 does not contribute to the transmission of the securing force at the contact surface between the overlapping portion 55 and the exterior insulating film 26 so as not to cause the creep deformation of the exterior insulating film 26 described above.
  • the gap 29 is set so as to ensure adequate sealing. That is, for example, the thickness of the overlapping portion 55 in the stacking direction is set to be thinner than the thickness of the contact portion 54 in the stacking direction by about twice the thickness of the exterior insulating film 26.
  • the assembled battery 100 of the present embodiment has the following operational effects in addition to the operational effects of the first to third embodiments.
  • (1) The overlapping part 55 which overlaps the protective part 19 covered with the exterior insulation film 26 and the exterior insulation film 26 on the spacer 53 is provided. Thereby, since the gap 29 between the contact portion 54 and the exterior insulating film 26 is covered with the overlapping portion 55, the insulation against an electrical short circuit is improved, and the durability of the assembled battery 100 can be improved.
  • the thickness of the overlapping portion 55 in the stacking direction does not contribute to the transmission of the securing force at the contact surface between the overlapping portion 55 and the exterior insulating film 26 so as not to cause the creep deformation of the exterior insulating film 26 described above.
  • it is set so that the sealing property of the gap 29 is appropriately secured from the viewpoint of securing electrical insulation. Thereby, the change of the securing force due to creep deformation of the exterior insulating film 26 does not occur. Therefore, since each cell 10 can be stably secured for a long period of time, the battery characteristics can be prevented from deteriorating and the durability of the assembled battery 100 can be improved.
  • the shape of the overlapping portion 55 described above is an example, and the present invention is not limited to this.
  • a gradually decreasing portion 56 in which the thickness in the stacking direction gradually decreases as the distance from the contact portion 54 in the vertical direction in the drawing may be provided between the overlapping portion 55 and the contact portion 54.
  • the surface is a flat surface, but may be a curved surface as shown in FIG.
  • the gradual decreasing portion 57 shown in FIG. 16 gradually increases in inclination as it moves away from the abutting portion 54 in the illustrated vertical direction, in other words, the abutting portion 54 and the overlapping portion 55 in FIG.
  • the step portion is configured to be rounded.
  • the number of the spacers 51, 52, 53 illustrated in each drawing in the one intermediate holder 41 and the end holder 46 is four, but the present invention is not limited to this. If the clamping force can be maintained and the surface pressure distribution due to the clamping force on the wide surface 12 is appropriate from the viewpoint of preventing deterioration of battery characteristics, the spacers 51, 52, 53 provided on one intermediate holder 41 and end holder 46 are provided. The number of may be other than four. If the surface pressure distribution due to the binding force on the wide surface 12 is appropriate from the viewpoint of preventing deterioration of battery characteristics, the contact area per spacer 51, 52, 53, You may set suitably the space
  • the present invention is not limited to the above-described embodiment, and a plurality of flat batteries having a pair of wide surfaces opposed to the battery container surface in the thickness direction of the battery container and the width of adjacent flat batteries are widened.
  • the surfaces are laminated facing each other, and a holding member that holds a plurality of flat batteries in a state where a predetermined compressive force is applied, and an exterior insulating film that covers the outer periphery of the battery container except for a part of the wide surface,
  • the holding member is provided between the wide surfaces facing each other in adjacent flat batteries, and has a spacer that contacts the non-protected portion that is not covered with the exterior insulating film in the wide surface at the contact portion. It includes an assembled battery having various features.

Abstract

The purpose of the invention is to improve the durability of an assembled battery. The assembled battery comprises: a plurality of flat batteries having a pair of wide width surfaces facing in a thickness direction of a battery container at the surface of the battery container; a holding member for making the wide width surfaces of adjacent flat batteries face each other to stack the flat batteries and holding the flat batteries while applying a predetermined compressive force thereto; and an exterior insulating film for covering the outer circumference of the battery container except for parts of the wide width surfaces. The holding member has a spacer provided between the wide width surfaces of adjacent flat batteries facing each other and touching non-protected portions of the wide width surfaces at touching portions, said non-protected portions being not covered with the exterior insulating film.

Description

組電池Assembled battery
　本発明は、リチウムイオン二次電池等の二次電池を用いた組電池に関する。 The present invention relates to an assembled battery using a secondary battery such as a lithium ion secondary battery.
　近年、地球温暖化等の問題から電気自動車（ＥＶ）や駆動の一部を電気モーターで補助するハイブリッド電気自動車（ＨＥＶ）が各自動車メーカーで開発され、その電源として高容量で高出力な二次電池が求められるようになってきた。このような要求に合致する電源として、高電圧を有する非水溶液系のリチウムイオン二次電池が注目されている。特に角形リチウムイオン二次電池はパック化した際の体積効率が優れているため、HEV用あるいはEV用として角形リチウムイオン二次電池の開発への期待が高まっている。 In recent years, electric vehicles (EVs) and hybrid electric vehicles (HEVs) that assist electric motors with electric motors have been developed by various automobile manufacturers due to problems such as global warming. Batteries have been demanded. As a power source that meets such requirements, a non-aqueous lithium ion secondary battery having a high voltage has attracted attention. In particular, prismatic lithium ion secondary batteries are excellent in volumetric efficiency when packed into packs, and therefore there is an increasing expectation for the development of prismatic lithium ion secondary batteries for HEVs or EVs.
　このリチウムイオン二次電池の反応では、充電時にはリチウムイオンが負極に挿入されることによって、当該リチウムイオン二次電池が膨らんでしまう。この状態を放置すると、リチウムイオン二次電池の劣化につながり、リチウムイオン二次電池の寿命を低下させてしまう。そのため、リチウムイオン二次電池同士を固縛して膨れを抑制する必要がある。 In the reaction of the lithium ion secondary battery, the lithium ion secondary battery swells by being inserted into the negative electrode during charging. If this state is left as it is, it will lead to deterioration of the lithium ion secondary battery and reduce the life of the lithium ion secondary battery. Therefore, it is necessary to tie up lithium ion secondary batteries and suppress swelling.
　一方で、リチウムイオン二次電池は安全性を高めるため、電池缶の外周部を絶縁する構造をとっている。たとえば、金属ケースを用いた蓄電装置において、金属ケースの外表面の一部に直接固着された樹脂フレームを備えると共に、金属ケースの外表面における少なくとも樹脂フレームが固着していない金属露出面が絶縁塗装膜によって覆われた二次電池が知られている（特許文献１参照）。 On the other hand, lithium ion secondary batteries have a structure that insulates the outer periphery of the battery can in order to increase safety. For example, a power storage device using a metal case includes a resin frame directly fixed to a part of the outer surface of the metal case, and at least an exposed metal surface on the outer surface of the metal case where the resin frame is not fixed is insulated. A secondary battery covered with a film is known (see Patent Document 1).
特開２０１０－９７８６５号公報JP 2010-97865 A
　一般に、二次電池は、内部に用いている電極活物質の種類によっては充放電に伴い電極自体が膨張収縮し、電池の体積が変化するものがある。リチウムイオン二次電池の場合、黒鉛系の活物質を負極に用いることがある。この黒鉛系活物質の寸法変化割合は、満充電から完全放電の間で、約１割と大きい。充放電に伴う膨張収縮をそのまま許容すると電池の性能が大きく低下するが、電池を外側から拘束すると性能低下を大幅に抑制できる。以下、電池を外側から拘束することを固縛と称する。 Generally, in some secondary batteries, depending on the type of electrode active material used therein, there are those in which the electrode itself expands and contracts with charge and discharge, and the volume of the battery changes. In the case of a lithium ion secondary battery, a graphite-based active material may be used for the negative electrode. The dimensional change ratio of the graphite-based active material is as large as about 10% between full charge and complete discharge. If the expansion and contraction associated with charging / discharging is allowed as it is, the performance of the battery is greatly reduced. However, if the battery is restrained from the outside, the performance deterioration can be greatly suppressed. Hereinafter, restraining the battery from the outside is referred to as lashing.
　特許文献１に記載の発明では、樹脂フレームを固着させた後に絶縁塗装を施しているため、作業性が悪く量産に不向きである。また、電池を固縛することに関して何ら考慮がされていない。 In the invention described in Patent Document 1, since the insulating coating is applied after the resin frame is fixed, workability is poor and unsuitable for mass production. In addition, no consideration is given to securing the battery.
　本発明による組電池は、電池容器表面に電池容器厚み方向に対向する一対の幅広面を有する複数の扁平形電池と、隣り合う扁平型電池の幅広面同士を互いに向かい合わせて積層し、所定の圧縮力を付与した状態で扁平電池を複数保持する保持部材と、幅広面の一部を除いて電池容器の外周を覆う外装絶縁フィルムとを備え、保持部材は、隣り合う扁平電池同士で互いに向かい合った幅広面同士の間に設けられて、幅広面のうち外装絶縁フィルムで覆われていない非保護部に当接部で当接するスペーサを有することを特徴とする。 The assembled battery according to the present invention is formed by laminating a plurality of flat batteries having a pair of wide surfaces facing the battery container thickness direction on the surface of the battery container and the wide surfaces of adjacent flat batteries facing each other. A holding member that holds a plurality of flat batteries in a state where compressive force is applied, and an exterior insulating film that covers the outer periphery of the battery container except for a part of the wide surface, the holding members face each other between adjacent flat batteries And a spacer that is provided between the wide surfaces and contacts the non-protected portion of the wide surface that is not covered with the exterior insulating film at the contact portion.
　本発明によれば、扁平形電池の電池特性の劣化を防止して、組電池の耐久性を大幅に向上できる。 According to the present invention, deterioration of the battery characteristics of the flat battery can be prevented, and the durability of the assembled battery can be greatly improved.
組電池の全体構成を示す分解図である。It is an exploded view which shows the whole structure of an assembled battery. 組電池を構成する単電池の積層状態を示す分解図である。It is an exploded view which shows the lamination | stacking state of the cell which comprises an assembled battery. 図２の一部を拡大した図である。It is the figure which expanded a part of FIG. 外装絶縁フィルムが巻かれた単電池の斜視図である。It is a perspective view of the cell by which the exterior insulation film was wound. 中間ホルダのスペーサが、スペーサ当接部へ当接する状態を模式的に示した断面図である。It is sectional drawing which showed typically the state which the spacer of an intermediate holder contact | abuts to a spacer contact part. 固縛力を与えることによる電池特性劣化の改善程度を示すデータである。It is data which shows the improvement degree of the battery characteristic degradation by giving a securing force. 中間ホルダのスペーサが、幅広面に貼られている外装絶縁フィルムへ当接する状態を模式的に示した断面図である。It is sectional drawing which showed typically the state which the spacer of an intermediate holder contact | abuts to the exterior insulation film stuck on the wide surface. 固縛力の低下について説明する図である。It is a figure explaining the fall of lashing force. 固縛力と単電池の厚さとの関係の一例を示すデータである。It is data which shows an example of the relationship between the securing force and the thickness of a single cell. 第２の実施の形態の外装絶縁フィルムを示す図である。It is a figure which shows the exterior insulation film of 2nd Embodiment. 第２の実施の形態の外装絶縁フィルムを電池容器に貼り付けた状態を示す図である。It is a figure which shows the state which affixed the exterior insulation film of 2nd Embodiment on the battery container. 第３の実施の形態における、中間ホルダのスペーサが、スペーサ当接部へ当接する状態を模式的に示した断面図である。It is sectional drawing which showed typically the state in which the spacer of an intermediate holder contact | abuts to a spacer contact part in 3rd Embodiment. 絶縁樹脂を隙間に充填した状態を説明する断面図である。It is sectional drawing explaining the state which filled the insulation resin in the clearance gap. 第４の実施の形態における、中間ホルダのスペーサと、スペーサ当接部および外装絶縁フィルムとの位置関係を模式的に示した断面図である。It is sectional drawing which showed typically the positional relationship of the spacer of an intermediate | middle holder, a spacer contact part, and an exterior insulation film in 4th Embodiment. 変形例を示す図である。It is a figure which shows a modification. 変形例を示す図である。It is a figure which shows a modification.
　図１～９を参照して、本発明による組電池の第１の実施の形態を説明する。図１は、本実施の形態の組電池１００の全体構成を示す分解図である。図２は、組電池１００を構成する単電池１０の積層状態を示す分解図であり、図３は、図２の一部を拡大した図である。組電池１００は、複数個の単電池１０と、電池セルホルダ４０と、固定部材１２０とを備えている。 A first embodiment of a battery pack according to the present invention will be described with reference to FIGS. FIG. 1 is an exploded view showing the overall configuration of the assembled battery 100 of the present embodiment. FIG. 2 is an exploded view showing a stacked state of the unit cells 10 constituting the assembled battery 100, and FIG. 3 is an enlarged view of a part of FIG. The assembled battery 100 includes a plurality of unit cells 10, a battery cell holder 40, and a fixing member 120.
　組電池１００が組み込まれる自動車等の移動体や蓄電システム等の仕様から組電池１００としての出力が決まり、組電池１００に組み込む単電池１０の員数が決まる。通常、組電池１００に組み込む単電池１０の員数は、数十セル程度である。この組電池１００を複数組み込んで構成した電池パックが自動車等の移動体や蓄電システム等に搭載される。 The output of the assembled battery 100 is determined from the specifications of a mobile object such as an automobile in which the assembled battery 100 is incorporated and the power storage system, and the number of single cells 10 incorporated in the assembled battery 100 is determined. Usually, the number of unit cells 10 incorporated in the assembled battery 100 is about several tens of cells. A battery pack configured by incorporating a plurality of the assembled batteries 100 is mounted on a moving body such as an automobile, a power storage system, or the like.
　組電池１００では、扁平型の複数個の単電池１０が積層された積層体１１０が、固定部材１２０によって単電池１０の積層方向（以下、単に積層方向と呼ぶ）に圧縮力が加えられた状態で拘束（固定）されている。積層体１１０は、複数個の単電池１０が電池セルホルダ４０によって保持されて積層されたものである。以下、固定部材１２０によって各単電池１０に積層方向へ圧縮力を加えた状態で積層体１１０を拘束することを固縛とも呼ぶ。また、固定部材１２０によって各単電池１０に加える積層方向への圧縮力を固縛力とも呼ぶ。 In the assembled battery 100, the stacked body 110 in which a plurality of flat unit cells 10 are stacked has a compressive force applied to the stacking direction of the single cells 10 (hereinafter simply referred to as the stacking direction) by the fixing member 120. It is restrained (fixed) by. The stacked body 110 is formed by stacking a plurality of unit cells 10 held by a battery cell holder 40. Hereinafter, restraining the stacked body 110 in a state where a compressive force is applied to each unit cell 10 in the stacking direction by the fixing member 120 is also referred to as lashing. The compressive force in the stacking direction applied to each unit cell 10 by the fixing member 120 is also referred to as lashing force.
　図１に示すように、固定部材は、一対の端板１２１と、一対の側板１２６とを備えている。一対の端板１２１は、それぞれ、積層体１１０に単電池の積層方向に当接して、積層体１１０に固縛力を与える厚板状の部材である。それぞれの端板１２１の厚さ方向に延在する側面には、側板１２６と締結するための締結ボルト１２５が螺合するネジ穴１２２が設けられている。 As shown in FIG. 1, the fixing member includes a pair of end plates 121 and a pair of side plates 126. Each of the pair of end plates 121 is a thick plate-like member that abuts the stacked body 110 in the stacking direction of the unit cells and applies a securing force to the stacked body 110. A screw hole 122 into which a fastening bolt 125 for fastening to the side plate 126 is screwed is provided on a side surface extending in the thickness direction of each end plate 121.
　一対の側板１２６は、一対の端板１２１で積層体１１０に固縛力を与えた状態で一対の端板１２１を固定する板状の部材である。それぞれの側板１２６には、複数の開口１２７と、複数の貫通孔１２８とが設けられている。開口１２７は、単電池１０を空冷するための空気の出入口となる開口であり、後述する側面開口４３の位置と対応する位置に設けられている。貫通孔１２８は、側板１２６と端板１２１とを締結するための締結ボルト１２５が挿通される貫通孔である。 The pair of side plates 126 are plate-like members that fix the pair of end plates 121 in a state in which a binding force is applied to the laminate 110 with the pair of end plates 121. Each side plate 126 is provided with a plurality of openings 127 and a plurality of through holes 128. The opening 127 is an opening serving as an air inlet / outlet for air-cooling the unit cell 10, and is provided at a position corresponding to a position of a side opening 43 described later. The through hole 128 is a through hole through which a fastening bolt 125 for fastening the side plate 126 and the end plate 121 is inserted.
　図２，３に示すように、電池セルホルダ４０は、隣り合う２つの単電池１０同士の間に設けられる中間ホルダ４１と、積層された単電池１０のうち、最も外側に位置する単電池１０の外側に設けられる端部ホルダ４６とを有する。電池セルホルダ４０は、電気絶縁性を有する樹脂で構成されている。 As shown in FIGS. 2 and 3, the battery cell holder 40 includes an intermediate holder 41 provided between two adjacent unit cells 10 and the unit cell 10 positioned on the outermost side among the stacked unit cells 10. And an end holder 46 provided on the outside. The battery cell holder 40 is made of an electrically insulating resin.
　中間ホルダ４１は、後述する単電池１０の厚さ方向に延在する側面である幅狭面１３、および、単電池１０の底面１４を支持するフレーム４２と、幅狭面１３および底面１４と直交する単電池１０の幅広面１２に後述するように直接当接するスペーサ５１とを備えている。中間ホルダ４１には、単電池１０を空冷するための空気の出入口となる側面開口４３が両側面に設けられている。 The intermediate holder 41 is perpendicular to the narrow surface 13, which is a side surface extending in the thickness direction of the unit cell 10 to be described later, and the frame 42 that supports the bottom surface 14 of the unit cell 10, and the narrow surface 13 and the bottom surface 14. And a spacer 51 that directly contacts the wide surface 12 of the unit cell 10 to be described later. The intermediate holder 41 is provided with side openings 43 on both sides serving as air inlets and outlets for air-cooling the unit cell 10.
　端部ホルダ４６は、後述する単電池１０の幅狭面１３および底面１４を支持するフレーム４７と、単電池１０の幅広面１２に直接当接するスペーサ５２とを備えている。なお、スペーサ５２は、端部ホルダ４６に対向する面で側板１２６に当接する。 The end holder 46 includes a frame 47 that supports the narrow surface 13 and the bottom surface 14 of the unit cell 10 to be described later, and a spacer 52 that directly contacts the wide surface 12 of the unit cell 10. The spacer 52 is in contact with the side plate 126 on the surface facing the end holder 46.
　スペーサ５１およびスペーサ５２は、それぞれ上下方向に離間して複数設けられている。 A plurality of spacers 51 and spacers 52 are provided apart from each other in the vertical direction.
　図４は、外装絶縁フィルム２６が巻かれた単電池１０の斜視図である。単電池１０は、扁平形のリチウムイオン二次電池であり、扁平した有底角筒容器（電池容器）１１に不図示の電池セル内捲回群が収容され、上蓋１５が被せられている。上蓋１５には、電池の端子１６が設けられている。電池容器１１は、幅広面１２と、幅狭面１３と、底面１４とを有する。幅広面１２は、電池容器１１の側面のうち、電池容器１１の厚み方向に対向する一対の面である。幅狭面１３は、電池容器１１の側面のうち、電池容器１１の厚み方向に延在する一対の面である。底面１４は、電池容器１１の底面である。 FIG. 4 is a perspective view of the unit cell 10 around which the exterior insulating film 26 is wound. The unit cell 10 is a flat lithium ion secondary battery, in which a non-illustrated wound group of battery cells is accommodated in a flat bottomed rectangular tube container (battery container) 11 and an upper lid 15 is covered. The upper lid 15 is provided with a battery terminal 16. The battery case 11 has a wide surface 12, a narrow surface 13, and a bottom surface 14. The wide surface 12 is a pair of surfaces facing the thickness direction of the battery container 11 among the side surfaces of the battery container 11. The narrow surface 13 is a pair of surfaces extending in the thickness direction of the battery case 11 among the side surfaces of the battery case 11. The bottom surface 14 is the bottom surface of the battery container 11.
　電池容器１１の側面には、外装絶縁フィルム２６が上下方向に離間して複数箇所に巻かれている。外装絶縁フィルム２６は、意図しない電気的な短絡を防止するための絶縁材であり、電池容器１１に貼り付けるための不図示の粘着層が一方の面に設けられている。外装絶縁フィルム２６は、捲回数が１回であり、帯状の外装絶縁フィルム２６の両端が、たとえば、電池容器１１の幅狭面１３で重複するように貼り付けられている。 On the side surface of the battery container 11, an exterior insulating film 26 is wound at a plurality of locations apart in the vertical direction. The exterior insulating film 26 is an insulating material for preventing an unintended electrical short circuit, and an adhesive layer (not shown) for attaching to the battery container 11 is provided on one surface. The exterior insulation film 26 has a number of wrinkles, and is attached so that both ends of the strip-like exterior insulation film 26 overlap, for example, the narrow surface 13 of the battery container 11.
　電池容器１１の側面で、外装絶縁フィルム２６が巻かれていない部分は電池容器１１の側面が露出している。電池容器１１の側面で、外装絶縁フィルム２６が巻かれている部分を保護部１９と呼び、外装絶縁フィルム２６が巻かれていない部分を非保護部１７と呼ぶ。非保護部１７のうち、幅広面１２上の露出部分をスペーサ当接部１８と呼ぶ。 In the side surface of the battery case 11, the side surface of the battery case 11 is exposed at a portion where the exterior insulating film 26 is not wound. On the side surface of the battery case 11, a portion around which the exterior insulating film 26 is wound is referred to as a protection portion 19, and a portion where the exterior insulation film 26 is not wound is referred to as a non-protection portion 17. Of the non-protection part 17, the exposed part on the wide surface 12 is called a spacer contact part 18.
　図５は、隣り合う単電池１０のそれぞれの幅広面１２で挟まれた中間ホルダ４１のスペーサ５１が、スペーサ当接部１８へ当接する状態を模式的に示した断面図である。なお、端部ホルダ４６に設けられたスペーサ５２と、スペーサ当接部１８との当接状態もスペーサ５１とスペーサ当接部１８との当接状態と同じであるので、図示による説明を省略する。 FIG. 5 is a cross-sectional view schematically showing a state in which the spacer 51 of the intermediate holder 41 sandwiched between the wide surfaces 12 of the adjacent unit cells 10 contacts the spacer contact portion 18. In addition, since the contact state between the spacer 52 provided on the end holder 46 and the spacer contact portion 18 is the same as the contact state between the spacer 51 and the spacer contact portion 18, the illustration is omitted. .
　中間ホルダ４１で単電池１０を保持すると、各スペーサ５１がそれぞれスペーサ当接部１８に当接する。同様に、端部ホルダ４６で単電池１０を保持すると、各スペーサ５２がそれぞれスペーサ当接部１８に当接する。換言すると、スペーサ５１およびスペーサ５２と、幅広面１２上の非保護部１７（すなわち電池容器１１の露出面）とが直接当接するように、外装絶縁フィルム２６が上下方向に離間して複数箇所に巻かれている。スペーサ５１，５２におけるスペーサ当接部１８との当接部分（当接面）を当接部５４と呼ぶ。 When the unit cell 10 is held by the intermediate holder 41, each spacer 51 comes into contact with the spacer contact portion 18. Similarly, when the unit cell 10 is held by the end holder 46, each spacer 52 comes into contact with the spacer contact portion 18. In other words, the exterior insulating film 26 is spaced apart in the vertical direction so that the spacer 51 and the spacer 52 and the non-protecting portion 17 (that is, the exposed surface of the battery container 11) on the wide surface 12 are in direct contact with each other. It is rolled up. A contact portion (contact surface) of the spacers 51 and 52 with the spacer contact portion 18 is referred to as a contact portion 54.
　中間ホルダ４１および端部ホルダ４６で単電池１０を保持して積層体１１０とし、一対の端板１２１で積層体１１０を積層方向から挟んで圧縮力を加え、一対の端板１２１と一対の側板１２６とを締結ボルト１２５で締結すると、積層体１１０が所定の圧縮力で固縛される。すなわち、端板１２１と端部ホルダ４６のスペーサ５２とが当接して、最も外側の単電池１０の幅広面に固縛力を伝達する。最も外側の単電池１０に伝達された固縛力は、隣り合う単電池１０に対して、幅広面１２同士で当接しているスペーサ５１を介して固縛力を伝達する。したがって、積層体１１０を構成するすべての単電池１０の幅広面１２に対して固縛力が付与される。 The unit cell 10 is held by the intermediate holder 41 and the end holder 46 to form a laminated body 110, and a pair of end plates 121 and a pair of side plates are applied with a compression force sandwiched between the laminated bodies 110 from the laminating direction. When the fastening body 126 is fastened with the fastening bolt 125, the laminate 110 is secured with a predetermined compressive force. That is, the end plate 121 and the spacer 52 of the end holder 46 come into contact with each other, and the lashing force is transmitted to the wide surface of the outermost unit cell 10. The securing force transmitted to the outermost unit cell 10 transmits the securing force to the adjacent unit cell 10 via the spacer 51 that is in contact with the wide surfaces 12. Therefore, a securing force is applied to the wide surfaces 12 of all the cells 10 constituting the stacked body 110.
　なお、積層体１１０の固縛力、すなわち、各単電池１０の積層方向に作用する圧縮力が低下すると、電池の特性が劣化する。不図示の電池セル内捲回群の構成部品のうち、負極には、その材料として電池容量の大きい黒鉛を用いる場合が多い。黒鉛負極は、充放電により膨張収縮を繰り返し、電池セル内捲回群を変形させることにより、特性が急激に劣化する。この変形を外部から拘束する、すなわち、固縛力を加えることにより、電池特性の劣化を大幅に改善できる。 In addition, when the fastening force of the laminated body 110, that is, the compressive force acting in the stacking direction of each unit cell 10, decreases, the battery characteristics deteriorate. Of the components in the battery cell winding group (not shown), graphite having a large battery capacity is often used for the negative electrode. The characteristics of the graphite negative electrode are rapidly deteriorated by repeatedly expanding and contracting by charging and discharging and deforming the wound group in the battery cell. By constraining this deformation from the outside, that is, by applying a securing force, it is possible to greatly improve the deterioration of battery characteristics.
　図６は、固縛力を与えることによる電池特性劣化の改善程度を示すデータである。図６では、横軸に充放電の回数、すなわち、サイクル数をとり、縦軸に特性の指針となる容量とDCRの変化率をとっている。容量とは電池が蓄えることのできる電気量であり、長期にわたり低下しないことが望ましい。また、DCRは電池の内部の電気抵抗であり、長期にわたり上昇しないことが望ましい。固縛力を与えた場合（固縛有りの場合）には、充放電回数が増加しても、容量およびDCRの変化率の変動は小さい。しかし、固縛力を与えない場合（固縛無しの場合）には、充放電回数の増加すると、容量が大きく低下し、DCRは大きく上昇する。 FIG. 6 is data showing the degree of improvement in battery characteristic deterioration caused by applying a securing force. In FIG. 6, the horizontal axis represents the number of charge / discharge cycles, that is, the number of cycles, and the vertical axis represents the capacity and the rate of change of DCR that serve as a guideline for characteristics. The capacity is the amount of electricity that the battery can store, and it is desirable that the capacity does not decrease over a long period of time. DCR is the electric resistance inside the battery, and it is desirable that it does not increase over a long period of time. When a securing force is applied (with securing), the change in capacity and DCR change rate is small even if the number of charge / discharge cycles increases. However, when no lashing force is applied (in the case of no lashing), as the number of charge / discharge increases, the capacity is greatly reduced and the DCR is greatly increased.
　本実施の形態とは異なって、幅広面１２とスペーサ５１との間に外装絶縁フィルム２６が存在する状態で、組電池１００を長期間運転した場合に固縛力が減少する（抜ける）理由を説明する。図７は、隣り合う単電池１０のそれぞれの幅広面１２で挟まれた中間ホルダ４１のスペーサ５１が、幅広面１２に貼られている外装絶縁フィルム２６へ当接する状態を模式的に示した断面図である。 Unlike the present embodiment, in the state where the exterior insulating film 26 exists between the wide surface 12 and the spacer 51, the reason why the securing force is reduced (disengaged) when the assembled battery 100 is operated for a long period of time. explain. FIG. 7 is a cross-sectional view schematically showing a state in which the spacer 51 of the intermediate holder 41 sandwiched between the wide surfaces 12 of the adjacent unit cells 10 is in contact with the exterior insulating film 26 attached to the wide surface 12. FIG.
　外装絶縁フィルム２６は、電池容器１１に貼り付けるために粘着層を有し、フィルム材自体も電池容器１１に巻くために柔軟性を有している必要がある。このような材料に対して固縛力による圧力を加え続けると、運転初期の状態では外装絶縁フィルム２６はその厚さを保っている。しかし、長期間にわたる運転の途中で図８に示すように外装絶縁フィルム２６がクリープ変形して薄くなる。この状態になると、固縛力が低下し、電池特性の劣化を早めることになる。 The exterior insulating film 26 has an adhesive layer to be attached to the battery container 11, and the film material itself needs to have flexibility in order to be wound around the battery container 11. If pressure due to the lashing force is continuously applied to such a material, the exterior insulating film 26 maintains its thickness in the initial operation state. However, during the operation over a long period of time, the exterior insulating film 26 is creep-deformed and thinned as shown in FIG. If it will be in this state, the securing force will fall and it will accelerate | stimulate deterioration of a battery characteristic.
　外装絶縁フィルム２６の厚さは通常0.05mm程度である。したがって、電池容器１１の両側の幅広面１２で合わせて0.1mm程度となる。この厚さ変化で、固縛力がどの程度抜けるのかを図９を用いて説明する。図９は固縛力、すなわち、荷重を増加させていった場合の単電池１０の厚さの変化の一例を示すデータである。電池の充電量をSOC(State of Charge)と称しており、図９はSOC=50%におけるデータである。単電池１０の幅広面１２に荷重2000Nを加えた場合の単電池１０の厚さ（セル厚み）は26.92mmである。この厚さを組電池１００に組み込む場合の設計寸法とする。 The thickness of the exterior insulating film 26 is usually about 0.05 mm. Therefore, the total of the wide surfaces 12 on both sides of the battery container 11 is about 0.1 mm. The extent to which the securing force is released due to this thickness change will be described with reference to FIG. FIG. 9 is data showing an example of a change in the thickness of the unit cell 10 when the securing force, that is, the load is increased. The amount of charge of the battery is called SOC (State of Charge), and FIG. 9 shows data at SOC = 50%. The thickness (cell thickness) of the unit cell 10 when the load 2000 N is applied to the wide surface 12 of the unit cell 10 is 26.92 mm. This thickness is used as a design dimension when the battery pack 100 is incorporated.
　組電池１００は組立て後の寸法を固定することになるので、充放電を行う際のセル厚みは設計寸法26.92mmに固定したままになる。この状態で充放電を行って荷重の変化を測定すると、放電によりSOCが0%となった場合の荷重は1000N程度まで下がり、充電によりSOCが100%になった場合の荷重は4000N程度まで上がる。 Since the assembled battery 100 has fixed dimensions after assembling, the cell thickness at the time of charging / discharging remains fixed at the design dimension of 26.92 mm. When charging and discharging are performed in this state and the change in load is measured, the load when SOC becomes 0% due to discharge decreases to about 1000N, and the load when SOC reaches 100% due to charging increases to about 4000N. .
　仮に、外装絶縁フィルム２６の一対の幅広面１２における厚さに相当する0.1mmだけセル厚みが厚くなることを許容すると、セル厚みは27.02mmとなる。この場合、SOC=50%での固縛力は700N程度となる。この状態で充放電を行うと、SOCの低い領域で固縛力が極めて小さくなり、電池特性の劣化を大幅に早めることになる。すなわち、仮に、幅広面１２とスペーサ５１との間に外装絶縁フィルム２６が存在した場合には、外装絶縁フィルム２６がクリープ変形して薄くなると、電池特性の劣化を大幅に早めることになる。 If the cell thickness is allowed to increase by 0.1 mm, which corresponds to the thickness of the pair of wide surfaces 12 of the exterior insulating film 26, the cell thickness is 27.02 mm. In this case, the securing force at SOC = 50% is about 700N. If charging / discharging is performed in this state, the securing force becomes extremely small in the low SOC region, and the deterioration of the battery characteristics is greatly accelerated. That is, if the exterior insulating film 26 exists between the wide surface 12 and the spacer 51, the deterioration of the battery characteristics is greatly accelerated if the exterior insulating film 26 is thinned by creep deformation.
　これに対して本実施の形態の組電池１００では、スペーサ５１と幅広面１２上の非保護部１７とが直接当接するので、外装絶縁フィルム２６のクリープ変形の影響を受けない。 On the other hand, in the assembled battery 100 according to the present embodiment, the spacer 51 and the non-protecting portion 17 on the wide surface 12 are in direct contact with each other, so that they are not affected by the creep deformation of the exterior insulating film 26.
　本実施の形態の組電池１００では、次の作用効果を奏する。
（１）　幅広面１２同士を互いに向かい合わせて扁平型の複数個の単電池１０を積層して積層体１１０を構成し、固定部材１２０によって単電池１０の積層方向に圧縮力を付与した状態で保持するように構成した。そして、スペーサ５１が、隣り合う単電池１０同士で互いに向かい合った幅広面１２同士の間に設けられて、幅広面１２に直接当接するように構成した。これにより、長期間にわたって安定的に各単電池１０に固縛力を与えられるので、電池特性の劣化を防止して、組電池１００の耐久性を大幅に向上できる。 The assembled battery 100 of the present embodiment has the following operational effects.
(1) In the state where a plurality of flat unit cells 10 are stacked with the wide surfaces 12 facing each other to form a stacked body 110, and a compressive force is applied in the stacking direction of the unit cells 10 by the fixing member 120. Configured to hold. The spacer 51 is provided between the wide surfaces 12 facing each other in the adjacent unit cells 10 and is configured to directly contact the wide surface 12. Thereby, since each cell 10 can be stably secured for a long period of time, deterioration of battery characteristics can be prevented and the durability of the assembled battery 100 can be greatly improved.
（２）　幅広面１２におけるスペーサ当接部１８以外の部分を外装絶縁フィルム２６で覆うように構成した。これにより、意図しない短絡を防止でき、組電池１００の耐久性を向上できる。 (2) A portion other than the spacer contact portion 18 on the wide surface 12 is covered with the exterior insulating film 26. Thereby, the unintended short circuit can be prevented and durability of the assembled battery 100 can be improved.
（３）　中間ホルダ４１の両側面に、単電池１０を空冷するための空気の出入口となる側面開口４３を設けた。これにより、外部の送風装置を用いて各単電池１０を効率的に冷却できるので、組電池１００の耐久性を向上できる。 (3) Side openings 43 serving as air inlets and outlets for air-cooling the unit cell 10 are provided on both side surfaces of the intermediate holder 41. Thereby, since each single battery 10 can be efficiently cooled using an external air blower, durability of the assembled battery 100 can be improved.
－－－第２の実施の形態－－－
　図１０，１１を参照して、本発明による組電池の第２の実施の形態を説明する。以下の説明では、第１の実施の形態と同じ構成要素には同じ符号を付して相違点を主に説明する。特に説明しない点については、第１の実施の形態と同じである。本実施の形態では、主に、外装絶縁フィルムの形状が第１の実施の形態と異なる。 --- Second Embodiment ---
A second embodiment of the assembled battery according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first embodiment. In the present embodiment, the shape of the exterior insulating film is mainly different from that of the first embodiment.
　図１０は、本実施の形態の外装絶縁フィルム２７を示す図である。本実施の形態の外装絶縁フィルム２７は、複数の開口２８を有する。各開口２８の形状、および、各開口２８の外装絶縁フィルム２７上での位置は、外装絶縁フィルム２７を電池容器１１の側面に巻き付けた際に、各開口２８が一対の幅広面１２に位置するように設定されている。さらに、各開口２８の形状、および、各開口２８の外装絶縁フィルム２７上での位置は、中間ホルダ４１および端部ホルダ４２が単電池１０に取り付けられた際に、幅広面１２にスペーサ５１，５２が当接する位置と一致するように設定されている。 FIG. 10 is a diagram showing the exterior insulating film 27 of the present embodiment. The exterior insulating film 27 of the present embodiment has a plurality of openings 28. The shape of each opening 28 and the position of each opening 28 on the exterior insulating film 27 are such that each opening 28 is positioned on the pair of wide surfaces 12 when the exterior insulating film 27 is wound around the side surface of the battery container 11. Is set to Further, the shape of each opening 28 and the position of each opening 28 on the exterior insulating film 27 are such that when the intermediate holder 41 and the end holder 42 are attached to the unit cell 10, the spacers 51, It is set so as to coincide with the position where 52 abuts.
　したがって、外装絶縁フィルム２７を電池容器１１に貼り付けると、図１１に示すように、幅広面１２上で、第１の実施の形態と同じ位置に保護部１９と非保護部１７が設けられ、幅狭面１３が外装絶縁フィルム２７で切れ目なく覆われる。 Therefore, when the exterior insulating film 27 is affixed to the battery container 11, as shown in FIG. 11, the protection part 19 and the non-protection part 17 are provided on the wide surface 12 at the same position as the first embodiment, The narrow surface 13 is covered with the exterior insulating film 27 without a break.
　本実施の形態の組電池１００では、第１の実施の形態の作用効果に加えて、次の作用効果を奏する。
（１）　単電池１０の側面に巻く外装絶縁フィルム２７を１枚とし、複数の開口２８を設けるように構成した。そして、各開口２８の形状、および、各開口２８の外装絶縁フィルム２７上での位置が、中間ホルダ４１および端部ホルダ４２が単電池１０に取り付けられた際に、幅広面１２にスペーサ５１，５２が当接する位置と一致するようにした。これにより、１つの単電池１０につき１枚の外装絶縁フィルム２７を巻けばよいので、フィルムの加工や巻いて貼り付ける作業の効率が向上する。 The assembled battery 100 of the present embodiment has the following operational effects in addition to the operational effects of the first embodiment.
(1) The exterior insulating film 27 wound around the side surface of the unit cell 10 is a single sheet, and a plurality of openings 28 are provided. The shape of each opening 28 and the position of each opening 28 on the exterior insulating film 27 are such that when the intermediate holder 41 and the end holder 42 are attached to the unit cell 10, the spacer 51, It was made to correspond with the position which 52 contact | abuts. Thereby, since one exterior insulation film 27 should just be wound per cell 10, the efficiency of the process of a film and the operation | work which rolls and affixes improves.
（２）　幅狭面１３が外装絶縁フィルム２７で切れ目なく覆われるようにしたので、電気的短絡に対する絶縁性が向上し、組電池１００の耐久性を向上できる。 (2) Since the narrow surface 13 is covered with the exterior insulating film 27 without interruption, the insulation against an electrical short circuit is improved and the durability of the assembled battery 100 can be improved.
－－－第３の実施の形態－－－
　図１２，１３を参照して、本発明による組電池の第３の実施の形態を説明する。以下の説明では、第１および第２の実施の形態と同じ構成要素には同じ符号を付して相違点を主に説明する。特に説明しない点については、第１および第２の実施の形態と同じである。本実施の形態では、主に、外装絶縁フィルム２６とスペーサ５１との間を絶縁樹脂６１で覆った点で第１および第２の実施の形態と異なる。 --- Third embodiment ---
A third embodiment of an assembled battery according to the present invention will be described with reference to FIGS. In the following description, the same components as those in the first and second embodiments are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first and second embodiments. This embodiment differs from the first and second embodiments mainly in that the space between the exterior insulating film 26 and the spacer 51 is covered with an insulating resin 61.
　図１２は、本実施の形態における、隣り合う単電池１０のそれぞれの幅広面１２で挟まれた中間ホルダ４１のスペーサ５１が、スペーサ当接部１８へ当接する状態を模式的に示した断面図である。中間ホルダ４１で単電池１０を保持すると、各スペーサ５１がそれぞれ当接部５４でスペーサ当接部１８に当接する。スペーサ当接部１８の図示上下方向の寸法は、スペーサ５１の図示上下方向の寸法より若干大きい。スペーサ当接部１８の図示上下方向の寸法とスペーサ５１の図示上下方向の寸法とが等しいことが理想である。 FIG. 12 is a cross-sectional view schematically showing a state in which the spacer 51 of the intermediate holder 41 sandwiched between the wide surfaces 12 of adjacent unit cells 10 abuts against the spacer abutting portion 18 in the present embodiment. It is. When the unit cell 10 is held by the intermediate holder 41, each spacer 51 comes into contact with the spacer contact portion 18 at the contact portion 54. The dimension of the spacer contact portion 18 in the illustrated vertical direction is slightly larger than the dimension of the spacer 51 in the illustrated vertical direction. Ideally, the vertical dimension of the spacer abutting portion 18 and the vertical dimension of the spacer 51 are equal.
　しかし、構成部品個々の寸法誤差や組立上の誤差を考慮すると、スペーサ５１が確実にスペーサ当接部１８に接触するように、スペーサ当接部１８の図示上下方向の寸法をスペーサ５１の図示上下方向の寸法より上記誤差の分だけ大きくする必要がある。そのため、スペーサ５１の図示上下には、外装絶縁フィルム２６との間に隙間２９が生じ、電池容器１１の表面である金属面が露出する。この露出部分から電気的短絡の生じるおそれがある。 However, when taking into account dimensional errors of individual components and assembly errors, the vertical dimension of the spacer abutting portion 18 is set to the upper and lower dimensions of the spacer 51 so that the spacer 51 reliably contacts the spacer abutting portion 18. It is necessary to make it larger than the dimension in the direction by the above error. Therefore, a gap 29 is formed between the spacer 51 and the exterior insulating film 26 on the upper and lower sides of the spacer 51, and the metal surface that is the surface of the battery container 11 is exposed. There is a risk of an electrical short circuit from this exposed portion.
　そこで、本実施の形態では、図１３に示すように、電気的絶縁性を有する絶縁樹脂６１を隙間２９に充填することで、電池容器１１の表面が露出しないようにしている。 Therefore, in the present embodiment, as shown in FIG. 13, the gap 29 is filled with an insulating resin 61 having electrical insulating properties so that the surface of the battery container 11 is not exposed.
　本実施の形態の組電池１００では、第１および第２の実施の形態の作用効果に加えて、次の作用効果を奏する。
（１）　スペーサ当接部１８の図示上下方向の寸法をスペーサ５１の図示上下方向の寸法より上記誤差の分だけ大きくした。これにより、スペーサ５１の当接部５４が外装絶縁フィルム２６を積層方向に圧迫することがないので、上述した外装絶縁フィルム２６のクリープ変形を起こすことがなく、固縛力の伝達に悪影響を及ぼさない。したがって、長期間にわたって安定的に各単電池１０に固縛力を与えられるので、電池特性の劣化を防止して、組電池１００の耐久性を大幅に向上できる。 The assembled battery 100 of the present embodiment has the following operational effects in addition to the operational effects of the first and second embodiments.
(1) The vertical dimension of the spacer abutting portion 18 in the figure is made larger than the vertical dimension of the spacer 51 in the figure by the above error. Accordingly, the contact portion 54 of the spacer 51 does not press the exterior insulating film 26 in the laminating direction, so that the above-described creep deformation of the exterior insulating film 26 does not occur and the transmission of the securing force is adversely affected. Absent. Therefore, since each cell 10 can be stably secured for a long period of time, the battery characteristics can be prevented from deteriorating and the durability of the assembled battery 100 can be greatly improved.
（２）　スペーサ５１，５２と外装絶縁フィルム２６との間の隙間２９に絶縁樹脂６１を充填した。これにより、電気的短絡に対する絶縁性が向上し、組電池１００の耐久性を向上できる。 (2) The insulating resin 61 was filled in the gap 29 between the spacers 51 and 52 and the exterior insulating film 26. Thereby, the insulation with respect to an electrical short circuit improves, and durability of the assembled battery 100 can be improved.
－－－第４の実施の形態－－－
　図１４を参照して、本発明による組電池の第４の実施の形態を説明する。以下の説明では、第１～第３の実施の形態と同じ構成要素には同じ符号を付して相違点を主に説明する。特に説明しない点については、第１～第３の実施の形態と同じである。本実施の形態では、主に、後述するスペーサ５３に外装絶縁フィルム２６と当接する部位を設けた点で第１～第３の実施の形態と異なる。 --- Fourth embodiment ---
A fourth embodiment of the assembled battery according to the present invention will be described with reference to FIG. In the following description, the same components as those in the first to third embodiments are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as in the first to third embodiments. This embodiment is different from the first to third embodiments mainly in that a portion that comes into contact with the exterior insulating film 26 is provided in a spacer 53 described later.
　図１４は、本実施の形態における、隣り合う単電池１０のそれぞれの幅広面１２で挟まれた中間ホルダ４１のスペーサ５３と、スペーサ当接部１８および外装絶縁フィルム２６との位置関係を模式的に示した断面図である。中間ホルダ４１で単電池１０を保持すると、各スペーサ５３がそれぞれ当接部５４でスペーサ当接部１８に当接する。また、本実施の形態のスペーサ５３は、外装絶縁フィルム２６で覆われている保護部１９と外装絶縁フィルム２６を介して重なる重複部５５を有する。 FIG. 14 schematically shows the positional relationship between the spacer 53 of the intermediate holder 41 sandwiched between the wide surfaces 12 of the adjacent unit cells 10, the spacer contact portion 18, and the exterior insulating film 26 in the present embodiment. FIG. When the unit cell 10 is held by the intermediate holder 41, each spacer 53 comes into contact with the spacer contact portion 18 at the contact portion 54. Further, the spacer 53 of the present embodiment has an overlapping portion 55 that overlaps with the protective portion 19 covered with the exterior insulating film 26 and the exterior insulating film 26.
　図１４に示すように、重複部５５は、スペーサ５３の当接部５４よりも図示上方および下方に延在する部位であり、図示左右方向（すなわち単電池１０の積層方向）の厚さが当接部５４よりも薄い。重複部５５の積層方向の厚さは、単電池１０を中間ホルダ４１で保持した際に、単電池１０に巻かれた外装絶縁フィルム２６に密着するように設定されている。但し、重複部５５の積層方向の厚さは、上述した外装絶縁フィルム２６のクリープ変形を起こさないように、重複部５５と外装絶縁フィルム２６との接触面では固縛力の伝達に寄与しないが、電気絶縁性の確保の観点から隙間２９の密閉性が適宜確保されるように設定されている。すなわち、たとえば、重複部５５の積層方向の厚さは、当接部５４の積層方向の厚さよりも外装絶縁フィルム２６の厚さのおおよそ２倍分だけ薄くなるように設定されている。 As shown in FIG. 14, the overlapping portion 55 is a portion extending upward and downward in the drawing relative to the abutting portion 54 of the spacer 53, and the thickness in the horizontal direction in the drawing (that is, the stacking direction of the unit cells 10) is the same. It is thinner than the contact portion 54. The thickness of the overlapping portion 55 in the stacking direction is set so as to be in close contact with the exterior insulating film 26 wound around the unit cell 10 when the unit cell 10 is held by the intermediate holder 41. However, the thickness in the stacking direction of the overlapping portion 55 does not contribute to the transmission of the securing force at the contact surface between the overlapping portion 55 and the exterior insulating film 26 so as not to cause the creep deformation of the exterior insulating film 26 described above. From the standpoint of securing electrical insulation, the gap 29 is set so as to ensure adequate sealing. That is, for example, the thickness of the overlapping portion 55 in the stacking direction is set to be thinner than the thickness of the contact portion 54 in the stacking direction by about twice the thickness of the exterior insulating film 26.
　本実施の形態の組電池１００では、第１～第３の実施の形態の作用効果に加えて、次の作用効果を奏する。
（１）　スペーサ５３に外装絶縁フィルム２６で覆われている保護部１９と外装絶縁フィルム２６を介して重なる重複部５５を設けた。これにより、当接部５４と外装絶縁フィルム２６との隙間２９が重複部５５で覆われるので、電気的短絡に対する絶縁性が向上し、組電池１００の耐久性を向上できる。 The assembled battery 100 of the present embodiment has the following operational effects in addition to the operational effects of the first to third embodiments.
(1) The overlapping part 55 which overlaps the protective part 19 covered with the exterior insulation film 26 and the exterior insulation film 26 on the spacer 53 is provided. Thereby, since the gap 29 between the contact portion 54 and the exterior insulating film 26 is covered with the overlapping portion 55, the insulation against an electrical short circuit is improved, and the durability of the assembled battery 100 can be improved.
（２）　上述した第３の実施の形態とは異なって、スペーサ５１，５２と外装絶縁フィルム２６との間の隙間２９に絶縁樹脂６１を充填する必要がないので、組電池１００の組み立て作業を容易化でき、製造コストを抑制できる。 (2) Unlike the above-described third embodiment, there is no need to fill the gap 29 between the spacers 51, 52 and the exterior insulating film 26 with the insulating resin 61. The manufacturing cost can be reduced.
（３）　重複部５５の積層方向の厚さは、上述した外装絶縁フィルム２６のクリープ変形を起こさないように、重複部５５と外装絶縁フィルム２６との接触面では固縛力の伝達に寄与しないが、電気絶縁性の確保の観点から隙間２９の密閉性が適宜確保されるように設定されている。これにより、外装絶縁フィルム２６のクリープ変形による固縛力の変化が生じない。したがって、長期間にわたって安定的に各単電池１０に固縛力を与えられるので、電池特性の劣化を防止して、組電池１００の耐久性を向上できる。 (3) The thickness of the overlapping portion 55 in the stacking direction does not contribute to the transmission of the securing force at the contact surface between the overlapping portion 55 and the exterior insulating film 26 so as not to cause the creep deformation of the exterior insulating film 26 described above. However, it is set so that the sealing property of the gap 29 is appropriately secured from the viewpoint of securing electrical insulation. Thereby, the change of the securing force due to creep deformation of the exterior insulating film 26 does not occur. Therefore, since each cell 10 can be stably secured for a long period of time, the battery characteristics can be prevented from deteriorating and the durability of the assembled battery 100 can be improved.
　なお、上述した重複部５５の形状は一例であって、本発明はこれに限定されない。たとえば、図１５に示すように、重複部５５と当接部５４との間に、当接部５４から図示上下方向に離れるにつれて積層方向の厚さが漸減する漸減部５６を設けてもよい。このように漸減部５６を設けることで、当接部５４から重複部５５にかけての形状変化が緩やかになり、漸減部５６を設けていない場合と比べて、当接部５４と重複部５５との間の部位に応力が集中しにくくなる。 Note that the shape of the overlapping portion 55 described above is an example, and the present invention is not limited to this. For example, as illustrated in FIG. 15, a gradually decreasing portion 56 in which the thickness in the stacking direction gradually decreases as the distance from the contact portion 54 in the vertical direction in the drawing may be provided between the overlapping portion 55 and the contact portion 54. By providing the gradually decreasing portion 56 in this way, the shape change from the abutting portion 54 to the overlapping portion 55 becomes gradual, and compared with the case where the gradually decreasing portion 56 is not provided, the contact portion 54 and the overlapping portion 55 are different. It becomes difficult for stress to concentrate on the part between.
　そのため、組電池１００の運転中に重複部５５に積層方向の意図しない応力が作用したとしても、たとえば当接部５４と重複部５５との間の部位など、スペーサ５３に亀裂が入るなどの不具合の発生を防止できる。したがって、長期間にわたって安定的に各単電池１０に固縛力を与えられるので、電池特性の劣化を防止して、組電池１００の耐久性を向上できる。 Therefore, even if unintended stress in the stacking direction is applied to the overlapping portion 55 during the operation of the assembled battery 100, for example, a defect such as a crack in the spacer 53 such as a portion between the contact portion 54 and the overlapping portion 55. Can be prevented. Therefore, since each cell 10 can be stably secured for a long period of time, the battery characteristics can be prevented from deteriorating and the durability of the assembled battery 100 can be improved.
　また、上述した漸減部５６では、表面が平面であるが、図１６に示すように曲面としてもよい。たとえば、図１６に示した漸減部５７は、当接部５４から図示上下方向に離れるにつれて徐々に傾きが増していくように、換言すれば、図１６上で当接部５４と重複部５５との段差部分を丸面取りしたように構成されている。漸減部５７をこのような形状とすることで、当接部５４から重複部５５にかけての形状変化が漸減部５６よりもさらに緩やかになり、当接部５４と重複部５５との間の部位に応力がさらに集中しにくくなる。 Further, in the above-described gradual reduction portion 56, the surface is a flat surface, but may be a curved surface as shown in FIG. For example, the gradual decreasing portion 57 shown in FIG. 16 gradually increases in inclination as it moves away from the abutting portion 54 in the illustrated vertical direction, in other words, the abutting portion 54 and the overlapping portion 55 in FIG. The step portion is configured to be rounded. By making the gradual decrease part 57 into such a shape, the shape change from the contact part 54 to the overlapping part 55 becomes more gradual than that of the gradual decrease part 56, and the part between the contact part 54 and the overlap part 55 is formed. Stress is less likely to concentrate.
　そのため、組電池１００の運転中に重複部５５に積層方向の意図しない応力が作用したとしても、たとえば当接部５４と重複部５５との間の部位など、スペーサ５３に亀裂が入るなどの不具合の発生を防止できる。したがって、長期間にわたって安定的に各単電池１０に固縛力を与えられるので、電池特性の劣化を防止して、組電池１００の耐久性を向上できる。 Therefore, even if unintended stress in the stacking direction is applied to the overlapping portion 55 during the operation of the assembled battery 100, for example, a defect such as a crack in the spacer 53 such as a portion between the contact portion 54 and the overlapping portion 55. Can be prevented. Therefore, since each cell 10 can be stably secured for a long period of time, the battery characteristics can be prevented from deteriorating and the durability of the assembled battery 100 can be improved.
　なお、上述の説明では、１つの中間ホルダ４１および端部ホルダ４６における各図で図示したスペーサ５１，５２，５３の本数が４本であるが、本発明はこれに限定されない。固縛力の維持ができ、幅広面１２における固縛力による面圧分布が電池特性劣化防止の観点から適切であれば、１つの中間ホルダ４１および端部ホルダ４６に設けるスペーサ５１，５２，５３の本数は４本以外の本数であってもよい。また、固縛力の維持ができ、幅広面１２における固縛力による面圧分布が電池特性劣化防止の観点から適切であれば、各スペーサ５１，５２，５３の１本当たりの接触面積や、隣り合うスペーサ５１，５２，５３との間隔は適宜設定してよい。 In the above description, the number of the spacers 51, 52, 53 illustrated in each drawing in the one intermediate holder 41 and the end holder 46 is four, but the present invention is not limited to this. If the clamping force can be maintained and the surface pressure distribution due to the clamping force on the wide surface 12 is appropriate from the viewpoint of preventing deterioration of battery characteristics, the spacers 51, 52, 53 provided on one intermediate holder 41 and end holder 46 are provided. The number of may be other than four. If the surface pressure distribution due to the binding force on the wide surface 12 is appropriate from the viewpoint of preventing deterioration of battery characteristics, the contact area per spacer 51, 52, 53, You may set suitably the space | interval with adjacent spacer 51,52,53.
　また、上述した各実施の形態および変形例は、それぞれ組み合わせてもよい。 Further, the above-described embodiments and modifications may be combined.
　なお、本発明は、上述した実施の形態のものに何ら限定されず、電池容器表面に電池容器厚み方向に対向する一対の幅広面を有する複数の扁平形電池と、隣り合う扁平型電池の幅広面同士を互いに向かい合わせて積層し、所定の圧縮力を付与した状態で扁平電池を複数保持する保持部材と、幅広面の一部を除いて電池容器の外周を覆う外装絶縁フィルムとを備え、保持部材は、隣り合う扁平電池同士で互いに向かい合った幅広面同士の間に設けられて、幅広面のうち外装絶縁フィルムで覆われていない非保護部に当接部で当接するスペーサを有することを特徴とする各種構造の組電池を含むものである。 The present invention is not limited to the above-described embodiment, and a plurality of flat batteries having a pair of wide surfaces opposed to the battery container surface in the thickness direction of the battery container and the width of adjacent flat batteries are widened. The surfaces are laminated facing each other, and a holding member that holds a plurality of flat batteries in a state where a predetermined compressive force is applied, and an exterior insulating film that covers the outer periphery of the battery container except for a part of the wide surface, The holding member is provided between the wide surfaces facing each other in adjacent flat batteries, and has a spacer that contacts the non-protected portion that is not covered with the exterior insulating film in the wide surface at the contact portion. It includes an assembled battery having various features.
１０　単電池、１１　電池容器、１２　幅広面、１７　非保護部、１８　スペーサ当接部、１９　保護部、２６，２７　外装絶縁フィルム、２９　隙間、４０　電池セルホルダ、４１　中間ホルダ、４２　フレーム、４３　側面開口、４６　端部ホルダ、４７　フレーム、５１，５２，５３　スペーサ、５４　当接部、５５　重複部、５６，５７　漸減部、１００　組電池、１１０　積層体、１２０　固定部材 10 cell, 11 battery container, 12 wide surface, 17 non-protection part, 18 spacer contact part, 19 protection part, 26, 27 exterior insulation film, 29 gap, 40 battery cell holder, 41 intermediate holder, 42 frame, 43 side face Opening, 46 end holder, 47 frame, 51, 52, 53 spacer, 54 abutting part, 55 overlapping part, 56, 57 gradually decreasing part, 100 assembled battery, 110 laminate, 120 fixing member

Claims (7)

  1. 　電池容器表面に電池容器厚み方向に対向する一対の幅広面を有する複数の扁平形電池と、
    　隣り合う前記扁平型電池の前記幅広面同士を互いに向かい合わせて積層し、所定の圧縮力を付与した状態で前記扁平電池を複数保持する保持部材と、
    　前記幅広面の一部を除いて前記電池容器の外周を覆う外装絶縁フィルムとを備え、
    　前記保持部材は、隣り合う前記扁平電池同士で互いに向かい合った前記幅広面同士の間に設けられて、前記幅広面のうち前記外装絶縁フィルムで覆われていない非保護部に当接部で当接するスペーサを有することを特徴とする組電池。     A plurality of flat batteries having a pair of wide surfaces facing the battery container thickness direction on the surface of the battery container;
    A holding member for holding a plurality of the flat cells in a state in which the wide surfaces of the adjacent flat cells are stacked facing each other and a predetermined compressive force is applied;
    An exterior insulating film covering an outer periphery of the battery container except for a part of the wide surface;
    The holding member is provided between the wide surfaces facing each other in the adjacent flat batteries, and abuts against a non-protection portion of the wide surface that is not covered with the exterior insulating film. An assembled battery comprising a spacer.
  2. 　請求項１に記載の組電池において、
    　前記外装絶縁フィルムは、前記当接部と離間して設けられていることを特徴とする組電池。     The assembled battery according to claim 1,
    The assembled battery, wherein the exterior insulating film is provided apart from the contact portion.
  3. 　請求項２に記載の組電池において、
    　前記スペーサは、前記幅広面のうち前記外装絶縁フィルムで覆われている保護部と前記外装絶縁フィルムを介して重なる重複部を有することを特徴とする組電池。     The assembled battery according to claim 2,
    The assembled battery according to claim 1, wherein the spacer includes a protective portion covered with the exterior insulating film on the wide surface and an overlapping portion overlapping with the exterior insulating film.
  4. 　請求項３に記載の組電池において、
    　前記スペーサは、前記重複部と前記当接部との間に、前記当接部から離れるにつれて厚さが漸減する漸減部を有することを特徴とする組電池。     The assembled battery according to claim 3,
    The assembled battery according to claim 1, wherein the spacer includes a gradually decreasing portion between which the thickness gradually decreases as the distance from the abutting portion increases between the overlapping portion and the abutting portion.
  5. 　請求項４に記載の組電池において、
    　前記漸減部の表面は、平面または曲面であることを特徴とする組電池。     The assembled battery according to claim 4,
    The assembled battery is characterized in that a surface of the gradually decreasing portion is a flat surface or a curved surface.
  6. 　請求項３～５のいずれか一項に記載の組電池において、
    　前記重複部は、前記外装絶縁フィルムと接触するフィルム接触面を有することを特徴とする組電池。     The assembled battery according to any one of claims 3 to 5,
    The battery pack is characterized in that the overlapping portion has a film contact surface that comes into contact with the exterior insulating film.
  7. 　請求項２に記載の組電池において、
    　前記非保護部は、前記当接部と前記外装絶縁フィルムとの間が絶縁樹脂で覆われていることを特徴とする組電池。     The assembled battery according to claim 2,
    The assembled battery, wherein the non-protection part is covered with an insulating resin between the contact part and the exterior insulating film.
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