Classifications

• • 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
  • H01M10/0431—Cells with wound or folded 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
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
  • H01M50/103—Primary casings; Jackets or wrappings 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
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/463—Separators, membranes or diaphragms 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
• • 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
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• Patent Document l JP-A-2011-96660
• an electrolyte solution is filled in a container through an electrolyte solution filling port formed in the container, and precharging is performed and, thereafter, the electrolyte solution filling port is sealed.
• a solution level of the electrolyte solution is high, bubbles formed by a gas generated in an electrolyte solution filling step (mainly precharging or a defoaming step) are popped in the vicinity of the electrolyte solution filling port and hence, the electrolyte solution overflows from the electrolyte solution filling port thus giving rise to a case where the electrolyte solution filling port cannot be sealed with certainty.
• the present invention has been made to overcome the above-mentioned drawbacks, and it is an object of the present invention to provide an energy storage device which can enhance reliability of sealing of the electrolyte solution filling port by suppressing the occurrence of a phenomenon that an electrolyte solution overflows from the electrolyte solution filling port and adheres to the electrolyte solution filling port in an electrolyte solution filling step.
• an energy storage device which includes : an electrode assembly which is formed by winding plates! a container which houses the electrode assembly! and a spacer which is interposed between the container and the electrode assembly, wherein the spacer has a wall portion which covers a top portion of a curved portion of the electrode assembly and a neighboring portion disposed adjacently to the top portion, and a plurality of recessed portions are formed on a surface of the wall portion which opposedly faces an inner surface of the container.
• the plurality of recessed portions are formed on the surface of the wall portion of the spacer on a container side and hence, it is possible to allow an electrolyte solution to enter the inside of the recessed portions. Therefore, a solution level of the electrolyte solution in the container can be lowered. Accordingly, even when bubbles generated in the electrolyte solution filling step are popped, the electrolyte solution minimally overflows from the electrolyte solution filling port. As a result, reliability of sealing of the electrolyte solution filling port can be enhanced.
• the spacer can be light-weighted due to the formation of the recessed portions.
• the wall portion may have rib portions which form the plurality of recessed portions.
• the plurality of recessed portions are formed by being surrounded by the rib portions and hence, portions of the wall portion whose strength is lowered due to the presence of the recessed portions can be reinforced by the rib portions.
• the container may have an opening through which the electrode assembly is inserted, and the rib portion may include first ribs extending in an insertion direction along which the spacer is inserted into the container, and second ribs extending in a direction which intersects with the insertion direction.
• a thickness of a bottom portion of the recessed portion and a thickness of the rib portion may be set substantially equal to each other.
• a thickness of the bottom portion of the recessed portion and a thickness of the rib portion are substantially equal to each other and hence, it is possible to suppress irregularities in thickness of the spacer as a whole. Accordingly, the deformation of the spacer caused by molding shrinkage due to irregularities in thickness can be suppressed and hence, a shape of the spacer can be maintained stably.
• the wall portion of the spacer may have a center region which opposedly faces the top portion of the curved portion of the electrode assembly and corner regions which are disposed adjacently to the center region, and the plurality of recessed portions may be formed in the corner regions.
• the plurality of recessed portions are formed in the corner regions other than the center region on the wall portion of the spacer and hence, a thickness of the center region can be reduced without being influenced by the recessed portion. Accordingly, a space for installing the electrode assembly can be broadened and hence, an outer size of the electrode assembly can be increased without increasing an inner size of the container.
• the container may be formed of a prismatic casing, and the spacer may be disposed so as to opposedly face at least one inner side surface of the container.
• the spacer is disposed so as to opposedly face at least one inner side surface of the container and hence, a portion of the spacer can be disposed at a corner portion of the container.
• a surplus space is formed at the corner portion of the container and hence, a thickness of the portion of the spacer can be increased by making use of the surplus space. Accordingly, rigidity of the spacer can be increased.
• an energy storage device which can enhance reliability of sealing of the electrolyte solution filling port by suppressing the occurrence of a phenomenon that an electrolyte solution overflows from the electrolyte solution filling port and adheres to the electrolyte solution filling port in an electrolyte solution filling step.
• Fig. 1 is a perspective view showing an external appearance of an energy storage device according to an embodiment.
• Fig. 2 is an exploded perspective view of the energy storage device according to the embodiment.
• Fig. 3 is an exploded perspective view of a lid plate structural body according to the embodiment.
• Fig. 4 is a perspective view showing the configuration of an electrode assembly according to the embodiment.
• Fig. 5 is a front view of a side spacer according to the embodiment as viewed from the outside.
• Fig. 6 is a back view of the side spacer according to the embodiment as viewed from the inside.
• Fig. 7 is a top plan view of the side spacer according to the
• Fig. 9 is a cross- sectional view schematically showing a state where the side spacer and the electrode assembly according to the embodiment are assembled to each other.
• Fig. 1 is a perspective view showing an external appearance of the energy storage device 10 according to the embodiment.
• Fig. 2 is an exploded perspective view of the energy storage device 10 according to the embodiment.
• Fig. 3 is an exploded perspective view of a lid structural body 180 according to the embodiment.
• the energy storage device 10 is a secondary battery capable of charging and discharging electricity.
• the energy storage device 10 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery.
• the energy storage device 10 is applicable to an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) or the like.
• the energy storage device 10 is not limited to a nonaqueous electrolyte secondary battery, and may be a secondary battery other than a nonaqueous electrolyte secondary battery, or may be a capacitor.
• the lid structural body 180 includes a lid plate 110 of the container 100, current collectors, and insulation members. To be more specific, the lid structural body 180 includes a positive electrode current collector 140 which is electrically connected to a tab portion 410 disposed on a positive electrode side of the electrode assembly 400 as the current collector. In the same manner, the lid structural body 180 includes a negative electrode current collector 150 which is electrically connected to a tab portion 420 disposed on a negative electrode side of the electrode assembly 400 as the current collector.
• the lid structural body 180 also includes a lower insulation member 120 disposed between the lid plate 110 and the positive electrode current collector 140 as the insulation member. In the same manner, the lid structural body 180 includes a lower insulation member 130 disposed between the lid plate 110 and the negative electrode current collector 150 as the insulation member.
• the lid structural body 180 further includes ⁇ a positive electrode terminal 200; a negative electrode terminal 300, an upper insulation member 125; and an upper insulation member 135.
• the upper insulation member 125 is disposed between the lid plate 110 and the positive electrode terminal 200.
• the upper insulation member 135 is disposed between the lid plate 110 and the negative electrode terminal 300.
• An upper spacer 500 and a buffer sheet 600 are disposed between the lid structural body 180 having the above-mentioned configuration and the electrode assembly 400.
• the upper spacer 500 is disposed between a side of the electrode assembly 400 on which the tab portions 410 and 420 are formed and the lid plate 110.
• the upper spacer 500 has a flat plate shape as a whole, and has two insertion portions 520 into which the tab portions 410 and 420 are inserted.
• the insertion portions 520 are formed on the upper spacer 500 in a notched shape.
• the upper spacer 500 is formed using a material having an insulation property such as polycarbonate (PC), polypropylene (PP), polyethylene (PE) or polyphenylene sulfide resin (PPS), for example.
• the upper spacer 500 functions as a member which directly or indirectly restricts the movement of the electrode assembly 400 in the upward direction (the direction toward the lid plate 110), or as a member which prevents short-circuiting between the lid structural body 180 and the electrode assembly 400.
• the buffer sheet 600 is a member which is formed using a porous material having high flexibility such as polyethylene foam, and functions as a buffer material between the electrode assembly 400 and the upper spacer 500.
• side spacers 700 are disposed between side surfaces (both side surfaces in the X axis direction in this embodiment) of the electrode assembly 400 in the direction which intersects with the direction that the electrode assembly 400 and the lid plate 110 are arranged in a row (Z axis direction) and inner peripheral surfaces of the container 100.
• the side spacers 700 play a role of restricting the position of the electrode assembly 400, for example.
• the side spacers 700 are formed using a material having an insulation property such as PC, PP, PE or PPS, for example.
• the energy storage device 10 may include other constitutional elements such as a buffer sheet disposed between the electrode assembly 400 and a bottom 113 of the container 100 (body 111).
• a buffer sheet disposed between the electrode assembly 400 and a bottom 113 of the container 100 (body 111).
• nonaqueous electrolyte nonaqueous electrolyte
• the illustration of the electrolyte solution is omitted.
• the container 100 is a prismatic casing, and includes the body 111 and the lid plate 110.
• a material for forming the body 111 and a material for forming the lid plate 110 are not particularly limited, it is preferable that the body 111 and the lid plate 110 be made of weldable metal such as stainless steel, aluminum or an aluminum alloy, for example.
• the body 111 is a cylindrical body having a rectangular shape as viewed in a plan view.
• the body 111 has an opening 112 on one end portion thereof and has the bottom 113 on the other end portion thereof.
• the electrode assembly 400, the side spacers 700 and the like are inserted into the body 111 of the container 100 through the opening 112.
• the direction that the electrode assembly 400, the side spacers 700 and the like are inserted into the body 111 through the opening 112 is assumed as the insertion direction (Z axis direction).
• An insulation sheet 350 which covers the electrode assembly 400 is disposed in the inside of the body 111.
• the insulation sheet 350 is formed using a material having an insulation property such as PC, PP, PE or PPS, for example.
• the insulation sheet 350 is made to overlap with inner peripheral surfaces of the body 111, and is positioned between the electrode assembly 400 and the body 111.
• the insulation sheet 350 is disposed so as to overlap with a pair of inner peripheral surfaces of the body 111 which forms long sides of the opening 112 as viewed in a plan view and an inner surface of the bottom 113.
• the body 111 is configured such that the electrode assembly 400, the insulation sheet 350 and the like are housed in the inside of the body 111 and, thereafter, the lid plate 110 is joined to the body 111 by welding or the like so that the inside of the body 111 is hermetically sealed.
• the lid plate 110 is a plate-like member which closes the opening 112 of the body 111. As shown in Fig. 2 and Fig. 3, a gas release vent 170, an electrolyte solution filling port 117, through holes 110a and 110b, and two bulging portions 160 are formed on the lid plate 110.
• the gas release vent 170 is opened when an internal pressure of the container 100 is increased so that the gas release vent 170 plays a role of releasing a gas in the inside of the container 100.
• the electrolyte solution filling port 117 is a through hole through which an electrolyte solution is filled in the container 100 at the time of manufacturing the energy storage device 10.
• An electrolyte solution filling plug 118 is disposed on the lid plate 110 so as to close the electrolyte solution filling port 117. That is, at the time of manufacturing the energy storage device 10, an electrolyte solution is filled in the container 100 through the electrolyte solution filling port 117, and the electrolyte solution filling port 117 is closed by welding the electrolyte solution filling plug 118 to the lid plate 110 so that the electrolyte solution is stored in the container 100.
• a kind of electrolyte solution sealed in the container 100 is not particularly limited provided that the performance of the energy storage device 10 is not impaired, and various electrolyte solutions can be selectively used.
• two respective bulging portions 160 are formed on the lid plate 110 by forming portions of the lid plate 110 into a bulged shape.
• the bulging portion 160 is used for positioning the upper insulation member 125 or 135, for example.
• a recessed portion (not shown in the drawing) which is indented upward is formed on a back side of the bulging portion 160, and an engaging projection 120b of the lower insulation member 120 or an engaging projection 130b of the lower insulation member 130 is engaged with a portion of the recessed portion.
• the lower insulation member 120 or 130 is also positioned, and is fixed to the lid plate 110 in such a state.
• the upper insulation member 125 is a member which electrically insulates the positive electrode terminal 200 and the lid plate 110 from each other.
• the lower insulation member 120 is a member which electrically insulates the positive electrode current collector 140 and the lid plate 110 from each other.
• the upper insulation member 135 is a member which electrically insulates the negative electrode terminal 300 and the lid plate 110 from each other.
• the lower insulation member 130 is a member which electrically insulates the negative electrode current collector 150 and the lid plate 110 from each other.
• the upper insulation member 125 and 135 may also be referred to as an upper gasket, for example.
• the lower insulation member 120 and 130 may also be referred to as a lower gasket, for example. That is, in this embodiment, the upper insulation members 125 and 135 and the lower insulation members 120 and 130 also have a function of sealing a space between the electrode terminal (200 or 300) and the container 100.
• the upper insulation members 125 and 135, and the lower insulation members 120 and 130 are formed using a material having an insulation property such as PC, PP, PE or PPS, for example.
• the engaging projection 130b which engages with the bulging portion 160 projects from an upper surface of the lower insulation member 130. Further, a recessed portion is formed on a lower surface of the lower insulation member 130, and the negative electrode current collector 150 is housed in the recessed portion. A through hole 130a which communicates with a through hole 150a formed in the negative electrode current collector 150 is formed in one end portion of the lower insulation member 130. A fastening portion 310 of the negative electrode terminal 300 is inserted into the through holes 130a, 150a.
• the engaging projection 120b which engages with the bulging portion 160 projects from an upper surface of the lower insulation member 120. Further, a recessed portion is formed on a lower surface of the lower insulation member 120, and the positive electrode current collector 140 is housed in the recessed portion. A through hole 120a which communicates with a through hole 140a formed in the positive electrode current collector 140 is formed in one end portion of the lower insulation member 120. A fastening portion 210 of the positive electrode terminal 200 is inserted into the through holes 120a, 140a. Further, a through hole 126 is formed in a portion of the lower insulation member 120 positioned directly below the electrolyte solution filling port 117. The through hole 126 guides an electrolyte solution which flows through the electrolyte solution filling port 117 in the direction toward the electrode assembly 400.
• the positive electrode terminal 200 is an electrode terminal electrically connected to a positive electrode of the electrode assembly 400 through the positive electrode current collector 140.
• the negative electrode terminal 300 is an electrode terminal electrically connected to a negative electrode of the electrode assembly 400 through the negative electrode current collector 150. That is, the positive electrode terminal 200 and the negative electrode terminal 300 are metal-made electrode terminals through which electricity stored in the electrode assembly 400 is discharged to a space outside the energy storage device 10, or through which electricity is introduced into a space inside the energy storage device 10 for storing the electricity in the electrode assembly 400.
• the positive electrode terminal 200 and the negative electrode terminal 300 are made of metal such as aluminum or an aluminum alloy.
• the fastening portion 210 for fastening the container 100 and the positive electrode current collector 140 with each other is formed on the positive electrode terminal 200.
• the fastening portion 310 for fastening the container 100 and the negative electrode current collector 150 with each other is formed on the negative electrode terminal 300.
• the fastening portion 210 is a shaft member (rivet) extending downward from the positive electrode terminal 200.
• the fastening portion 210 is inserted into the through hole 140a formed in the positive electrode current collector 140, and fastens the positive electrode terminal 200 and the positive electrode current collector 140 together by caulking.
• the fastening portion 210 is inserted into the through hole 125a formed in the upper insulation member 125, the through hole 110a formed in the lid plate 110, the through hole 120a formed in the lower insulation member 120, and the through hole 140a formed in the positive electrode current collector 140, and fastens the positive electrode terminal 200, the upper insulation member 125, the lid plate 110, the lower insulation member 120 and the positive electrode current collector 140 together by caulking.
• the positive electrode terminal 200 and the positive electrode current collector 140 are electrically connected to each other, and the positive electrode current collector 140 is fixed to the lid plate 110 together with the positive electrode terminal 200, the upper insulation member 125 and the lower insulation member 120.
• the fastening portion 310 is a shaft member (rivet) extending downward from the negative electrode terminal 300.
• the fastening portion 310 is inserted into the through hole 150a formed in the negative electrode current collector 150, and fastens the negative electrode terminal 300 and the negative electrode current collector 150 together by caulking.
• the fastening portion 310 is inserted into the through hole 135a formed in the upper insulation member 135, the through hole 110b formed in the lid plate 110, the through hole 130a formed in the lower insulation member 130, and the through hole 150a formed in the negative electrode current collector 150, and fastens the negative electrode terminal 300, the upper insulation member 135, the lid plate 110, the lower insulation member 130, and the negative electrode current collector 150 together by caulking.
• the negative electrode terminal 300 and the negative electrode current collector 150 are electrically connected to each other, and the negative electrode current collector 150 is fixed to the lid plate 110 together with the negative electrode terminal 300, the upper insulation member 135 and the lower insulation member 130.
• the fastening portion 310 may be formed as an integral part of the negative electrode terminal 300. Alternatively, the fastening portion 310 may be formed as a part separate from the negative electrode terminal 300 and may be fixed to the negative electrode terminal 300 by a technique such as caulking or welding.
• the fastening portion 310 may be made of metal such as copper or a copper alloy which differs from metal for forming the negative electrode terminal 300. The same goes for the relationship in material between the fastening portion 210 and the positive electrode terminal 200.
• the positive electrode current collector 140 is a member disposed between the electrode assembly 400 and the container 100 for electrically connecting the electrode assembly 400 and the positive electrode terminal 200 to each other.
• the positive electrode current collector 140 is made of metal such as aluminum or an aluminum alloy. To be more specific, the positive electrode current collector 140 is electrically connected to the tab portion 410 on a positive electrode side of the electrode assembly 400 and, at the same time, is electrically connected to the fastening portion 210 of the positive electrode terminal 200.
• the negative electrode current collector 150 is a member disposed between the electrode assembly 400 and the container 100 for electrically connecting the electrode assembly 400 and the negative electrode terminal 300 to each other.
• the negative electrode current collector 150 is made of metal such as copper or a copper alloy. To be more specific, the negative electrode current collector 150 is electrically connected to the tab portion 420 on a negative electrode side of the electrode assembly 400 and, at the same time, is electrically connected to the fastening portion 310 of the negative electrode terminal 300.
• Fig. 4 is a perspective view showing the configuration of the electrode assembly 400 according to the embodiment.
• Fig. 4 shows the electrode assembly 400 in a wound state in a partially developed manner.
• the electrode assembly 400 is a power generating element which can store electricity.
• the electrode assembly 400 is formed such that a positive electrode 450, a negative electrode 460 and separators 470a and 470b are alternately stacked with each other and wound around each other. That is, the electrode assembly 400 is formed such that the positive electrode 450, the separator 470a, the negative electrode 460, and the separator 470b are stacked with each other in this order and, then, are wound around each other so as to form an elongated circular shape in cross section.
• the negative electrode 460 is a plate where a negative active material layer is formed on surfaces of a negative electrode substrate layer formed using a metal foil having an elongated strip shape and made of copper, a copper alloy or the like.
• a negative active material used for forming the negative active material layer known materials can be used as desired provided that the negative active materials can occlude and discharge lithium ions.
• a negative active material in addition to lithium metal and a lithium alloy (an alloy containing lithium metal such as lithium - aluminum, lithium - lead, lithium - tin, lithium -aluminum - tin, lithium -gallium or Wood's alloy), an alloy which can occlude and discharge lithium, a carbon material (for example, graphite, minimally graphitizable carbon, easily graphitizable carbon, low
• the separator 470a and 470b is formed using a microporous sheet made of a resin.
• a material for forming the separator 470a and 470b used in the energy storage device 10 known materials can be used as desired provided that performances of the energy storage device 10 are not deteriorated.
• the positive electrode 450 has a plurality of projecting portions 411 projecting outward on one edge thereof in the direction of a winding axis.
• the negative electrode 460 also has a plurality of projecting portions 421 projecting outward on one edge thereof in the direction of the winding axis.
• the plurality of projecting portions 411 and the plurality of projecting portions 421 are portions where an active material is not applied by coating so that a substrate layer is exposed (active material non-coated portions).
• the winding axis is an imaginary axis which is used as a center axis at the time of winding the positive electrode 450, the negative electrode 460 and the like.
• the winding axis is a straight line which passes the center of the electrode assembly 400 and extends parallel to the Z axis direction.
• the plurality of projecting portions 411 and the plurality of projecting portions 421 are disposed on an edge of the positive electrode 450 and on an edge of the negative electrode 460 on the same side in the direction of the winding axis (edges on a plus side in the Z axis direction in Fig. 4).
• the positive electrode 450 and the negative electrode 460 are stacked with each other, the plurality of projecting portions 411 and the plurality of projecting portions 421 are respectively stacked with each other at
• the plurality of projecting portions 411 are stacked on one edge of the positive electrode 450 in the direction of the winding axis at a predetermined position in the circumferential direction.
• the plurality of projecting portions 421 are stacked on one edge of the negative electrode 460 in the direction of the winding axis at a predetermined position in the circumferential direction which differs from the position where the plurality of projecting portions 411 are stacked.
• the tab portion 410 formed by stacking the plurality of projecting portions 411 and the tab portion 420 formed by stacking the plurality of projecting portions 421 are formed on the electrode assembly 400.
• the tab portion 410 is gathered toward the center in the stacking direction, for example, and is bonded to the positive electrode current collector 140 by ultrasonic welding, for example.
• the tab portion 420 is gathered toward the center in the stacking direction, for example, and is bonded to the negative electrode current collector 150 by ultrasonic welding, for example.
• the tab portion (410, 420) is a portion through which electricity is introduced into and discharged from the electrode assembly 400, and may be referred to as "lead (portion)", “current collecting portion” or the like.
• the tab portion 410 is formed by stacking the projecting portions 411 where the substrate layer is exposed and hence, the tab portion 410 does not contribute to the generation of electricity.
• the tab portion 420 is formed by stacking the projecting portions 421 where the substrate layer is exposed and hence, the tab portion 420 does not contribute to the generation of electricity.
• portions of the electrode assembly 400 other than the tab portions 410 and 420 are formed by stacking portions where an active material is applied to the substrate layer by coating and hence, such portions contribute to the generation of electricity.
• body portion 430 such a portion is referred to as "body portion 430".
• Both end portions of the body portion 430 in the X axis direction form curved portions 431 and 432 each of which has a curved outer peripheral surface.
• Portions of the electrode assembly 400 disposed between the curved portions 431 and 432 form flat portions 433 having a flat outer side surface.
• the electrode assembly 400 is formed into an elongated circular shape where the flat portions 433 are disposed between two curved portions 431 and 432.
• the side spacer 700 on a negative electrode side is exemplified. Since the side spacer 700 on a positive electrode side has substantially the same configuration, the description of the configuration of the side spacer 700 on the positive electrode side is omitted.
• Fig. 5 is a front view of the side spacer 700 according to the embodiment as viewed from the outside.
• Fig. 6 is a back view of the side spacer 700 according to the embodiment as viewed from the inside.
• Fig. 7 is a top plan view of the side spacer 700 according to the embodiment.
• Fig. 8 is a cross- sectional view of the side spacer 700 according to the embodiment taken along a line XIII-XIII in Fig. 5 included in an X-Y plane.
• the side spacer 700 is an elongated member extending in the insertion direction (Z axis direction), and is formed using a material having an insulation property such as PC, PP, PE or PPS.
• the side spacers 700 are disposed so as to opposedly face a pair of short side surfaces out of inner side surfaces of the body 111 of the container 100.
• Each side spacer 700 is an integral body formed of a wall portion 710; and a proximal portion 720 joined to an upper end portion of the wall portion 710.
• the wall portion 710 has a lower end portion thereof opened.
• the wall portion 710 is a portion which extends in the insertion direction, and covers one side portion of the electrode assembly 400. To be more specific, the wall portion 710 covers a top portion of the curved portion 432 of the electrode assembly 400 and a neighboring portion which is disposed adjacently to the top portion. The neighboring portion is a portion which is disposed adjacently to and continuously formed with the top portion of the curved portion 432. As shown in Fig. 7 and Fig. 8, an inner side surface 711 of the wall portion 710 disposed on an inner side of the container 100 is a surface which opposedly faces the curved portion 432 of the electrode assembly 400, and is formed of a smooth curved surface which corresponds to the curved portion 432.
• the inner side surface 711 of the wall portion 710 is brought into contact with the curved portion 432 of the electrode assembly 400. That is, the inner side surface 711 of the wall portion 710 forms a contact portion which is brought into contact with the curved portion 432.
• An outer side surface 712 of the wall portion 710 disposed on a container 100 side is formed such that a pair of corner portions is formed into a rounded shape corresponding to an inner shape of the container 100.
• This pair of rounded portions opposedly faces the pair of corner portions of an inner portion of the container 100 having a rectangular shape which are disposed adjacently to each other.
• the pair of rounded portions of the wall portion 710 forms corner regions 713, and a portion of the wall portion 710 disposed adjacently to the pair of corner regions 713 and is sandwiched between the pair of corner regions 713 forms a center region 714.
• the center region 714 is a region which covers a top portion of the curved portion 432 of the electrode assembly 400, and the corner regions 713 are regions which cover side portions of the top portion of the curved portion 432.
• the outer side surface 712 of each corner region 713 has a rib portion 730, and a plurality of recessed portions 716 are formed by the rib portion 730.
• the rib portion 730 includes a plurality of first ribs 731 extending in the insertion direction, and a plurality of second ribs 732 extending in the direction which intersects with the insertion direction (Y axis direction).
• the plurality of bottomed recessed portions 716 are respectively formed into a rectangular shape by the plurality of first ribs 731 and the plurality of second ribs 732, and are arranged in a matrix array.
• the inner side surface 711 is formed of a curved surface, and the recessed portions 716 are not formed in the center region 714. Accordingly, a thickness T2 of the center region 714 can be set substantially smaller than a thickness Tl of the corner region 713. In such a structure, the thicknesses Tl, T2 are thicknesses in the normal direction of the inner side surface 711. In this manner, a thickness of the center region 714 can be decreased without being influenced by the recessed portions 716. Accordingly, a space in which the electrode assembly 400 is installed can be expanded and hence, an outer size of the electrode assembly 400 can be increased without increasing an inner size of the body 111 of the container 100.
• the shape of the recessed portion 716 is not limited to a rectangular shape, and the recessed portion 716 can be formed into any desired shape.
• the recessed portion 716 may be formed into a circular shape, an elliptical shape, or a polygonal shape besides a rectangular shape. All of the plurality of recessed portions 716 may have the same shape, or may have different shapes.
• the arrangement of the plurality of recessed portions 716 is not limited to a matrix array, and the plurality of recessed portions 716 may be arranged in any desired pattern.
• the plurality of recessed portions 716 may be arranged only either in one row or in one column, or may be arranged in a staggered manner or in a random manner.
• a thickness T3 of a bottom portion 7161 of the recessed portion 716 is substantially equal to a thickness of the first rib 731 and a thickness of the second rib 732 (a thickness T4 of the first rib 731 being shown in Fig. 8). With such a configuration, it is possible to suppress irregularities in thickness of the side spacer 700 as a whole. When there are irregularities in thickness, in forming the side spacer 700 by molding using a resin, there may be a case where the side spacer 700 is deformed due to molding shrinkage caused by curing of the resin.
• the proximal portion 720 includes a top plate 721 and a peripheral wall 722.
• a slit may be formed in the top plate 721.
• the peripheral wall 722 is formed on an upper surface of the top plate 721. A portion of the peripheral wall 722 which corresponds to one side 723 of the top plate 721 is opened, and other portions of the peripheral wall 722 are raised from the top plate 721 along a side of the top plate 721. A recessed portion 715 is formed on a center portion of the peripheral wall 722.
• Fig. 9 is a cross- sectional view schematically showing a state where the side spacer 700 and the electrode assembly 400 according to the embodiment are assembled to each other. For the sake of convenience of the description, only a profile line of the electrode assembly 400 is shown in the drawing and hatching is not added to the electrode assembly 400.
• the positive electrode 450, the negative electrode 460, the separators 470a and 470b are the positive electrode 450, the negative electrode 460, the separators 470a and 470b.
• an adhesive tape (not shown in the drawing) is adhered to the flat portion 433 of the electrode assembly 400 so as to prevent the developing of the electrode assembly 400.
• a plate body which forms the negative electrode current collector 150 is prepared.
• the plate body is bent by approximately 90 degrees.
• the lid plate 110, the lower insulation member 130, the upper insulation member 135 and the negative electrode terminal 300 are assembled to a portion of the plate body which corresponds to the first connecting portion 151.
• the fastening portion 310 of the negative electrode terminal 300 is inserted into the through hole 135a formed in the upper insulation member 135, the through hole 110b formed in the lid plate 110, the through hole 130a formed in a lower insulation member 130, and the through hole 150a formed in the plate body, and the fastening portion 310 clamps these members together by caulking.
• a plate body for forming the negative electrode current collector 150 is mounted on the lid structural body 180.
• the tab portion 420 of the electrode assembly 400 is fixed to the plate body which forms the negative electrode current collector 150 by welding. After the tab portion 420 is fixed to the plate body by welding, the plate body is further bent by approximately 90 degrees so that the negative electrode current collector 150 shown in Fig. 3 is formed.
• the positive electrode current collector 140 is mounted on the lid plate structural body 180, and is joined to the tab portion 410 of the electrode assembly 400.
• the side spacers 700 are mounted on the body portion 430 of the electrode assembly 400.
• the side spacer 700 is mounted on the curved portion 431 and the curved portion 432 of the body portion 430 individually.
• each side spacer 700 is fixed to the body portion 430 by an adhesive tape (not shown in the drawing).
• the electrode assembly 400 and the side spacers 700 which are formed into an integral body are housed in the body 111 of the container 100.
• the electrode assembly 400 and the side spacers 700 are inserted into the body 111 of the container 100 through the opening 112 of the body 111.
• the side spacers 700 are pushed from a lid structural body 180 side and hence, a large force is applied to the wall portion 710.
• the wall portion 710 intends to expand.
• the top plate 721 is connected to one end portion of the wall portion 710 and hence, the deformation of the wall portion 710 is suppressed by the top plate 721.
• rigidity of the side spacer 700 in the extending direction of the first ribs 731 is increased by the first ribs 731 extending in the insertion direction. With such a configuration, the side spacers 700 are minimally deformed at the time of inserting the side spacers 700 into the container 100.
• the electrode assembly 400 and the side spacers 700 can be smoothly inserted into the body 111 by pushing.
• the lid plate 110 is welded to the body 111 so as to assemble the container 100.
• an electrolyte solution is filled in the container 100 through the electrolyte solution filling port 117.
• the electrolyte solution When a solution level of the electrolyte solution is high after the electrolyte solution is filled in the container 100, the electrolyte solution overflows from the electrolyte solution filling port 117 in precharging or in a defoaming step in the electrolyte solution filling step. Accordingly, there is a concern that the electrolyte solution adheres to the electrolyte solution filling port so that the electrolyte solution filling port 117 cannot be sealed with certainty.
• the plurality of recessed portions 716 are formed on each side spacer 700 and hence, it is possible to allow the electrolyte solution to enter the inside of the recessed portions 716 whereby a solution level of the electrolyte solution in the container 100 can be lowered. Accordingly, even when bubbles generated in the electrolyte solution filling step are popped, the electrolyte solution minimally overflows from the electrolyte solution filling port. As a result, reliability of sealing of the electrolyte solution filling port 117 can be enhanced.
• the electrolyte solution filling plug 118 is welded to the lid plate 110 for closing the electrolyte solution filling port 117 so that the energy storage device 10 is manufactured.
• the plurality of recessed portions 716 are formed on the surface of the wall portion 710 of the side spacer 700 on the container 100 side and hence, it is possible to allow an electrolyte solution to enter the inside of the recessed portions 716.
• a solution level of the electrolyte solution in the container 100 can be lowered. Accordingly, even when bubbles generated in the electrolyte solution filling step are popped, the electrolyte solution minimally overflows from the electrolyte solution filling port and hence, the adhesion of the electrolyte solution to the electrolyte solution filling port can be suppressed. As a result, reliability of sealing of the electrolyte solution filling port 117 can be enhanced.
• the plurality of recessed portions 716 are formed by being
• portions of the wall portion 710 whose strength is lowered due to the presence of the recessed portions 716 can be reinforced by the rib portions 730.
• the side spacer 700 includes the first ribs 731 extending in the insertion direction and hence, rigidity of the side spacer 700 in the insertion direction can be increased by the first ribs 731.
• the side spacer 700 also includes the second ribs 732 extending in the direction which intersects with the insertion direction and hence, the deformation of the side spacer 700 caused by expansion or shrinkage of the electrode assembly 400 can be suppressed by the second ribs 732.
• the thickness T3 of the bottom portion 7161 of the recessed portion 716 and the thickness T4 of the rib portion 730 are substantially equal to each other and hence, it is possible to suppress irregularities in thickness of the side spacer 700 as a whole. Accordingly, the deformation of the side spacer 700 caused by molding shrinkage due to irregularities in thickness can be suppressed and hence, the shape of the side spacer 700 can be maintained stably. It is preferable that the thickness T3 and the thickness T4 completely agree with each other. However, even when the thickness T3 and the thickness T4 differ from each other by an amount which falls within a predetermined range, it is assumed that the thickness T3 and the thickness T4 are "substantially equal to each other".
• the predetermined range may be a range where a deformation amount of the side spacer 700 caused by molding shrinkage falls within a range of an allowable
• the plurality of recessed portions 716 are formed in the corner regions 713 other than the center region 714 on the wall portion 710 of the side spacer 700 and hence, a thickness of the center region 714 can be decreased without being influenced by the recessed portions 716.
• a space for installing the electrode assembly 400 can be expanded and hence, an outer size of the electrode assembly 400 can be increased without increasing an inner size of the container 100.
• the winding type electrode assembly 400 when the winding type electrode assembly 400 is housed in the body 111 of the container 100 which is a prismatic casing, a surplus space never fails to be formed at corner portions of the casing. In this
• the side spacers 700 are disposed so as to opposedly face a pair of short side surfaces of the body 111 of the container 100 and hence, it is possible to dispose the corner regions 713 of the side spacers 700 in the surplus spaces. Accordingly, a thickness of the corner region 713 of each side spacer 700 can be increased corresponding to the surplus space and hence, rigidity of the side spacers 700 can be increased.
• the energy storage device according to the present invention has been described with reference to the above-mentioned embodiment.
• the present invention is not limited to the above-mentioned embodiment. Unless the configurations depart from the gist of the present invention, embodiments acquired by applying various modifications conceived by those who are skilled in the art to the above-mentioned embodiment and configurations acquired by combining the above-described plurality of constitutional elements also fall within the scope of the present invention.
• the number of electrode assemblies 400 which the energy storage device 10 includes is not limited to one, and may be two or more.
• the energy storage device 10 includes a plurality of electrode assemblies 400 it is sufficient that a pair of side spacers 700 is mounted on each electrode assembly 400.
• the positional relationship between the tab portion 410 of the electrode assembly 400 on a positive electrode side and the tab portion 420 of the electrode assembly 400 on a negative electrode side is not particularly limited.
• the tab portion 410 and the tab portion 420 may be disposed on sides opposite to each other in the direction of the winding axis.
• a tab portion on a positive electrode side and a tab portion on a negative electrode side may be formed such that the tab portions project in different directions. In this case, it is sufficient that lower insulation members, current collectors and the like are disposed at positions which correspond to the tab portion on the positive electrode side and the tab portion on the negative electrode side respectively.
• the wall portion 710 of the side spacer 700 has lower end portion thereof opened.
• the lower end portion of the wall portion 710 of the side spacer 700 may be closed by a bottom plate.
• the present invention is applicable to an energy storage device such as a lithium ion secondary battery.

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• Engineering & Computer Science (AREA)
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• Secondary Cells (AREA)
• Electric Double-Layer Capacitors Or The Like (AREA)
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• 2016
  • 2016-02-29 JP JP2016038468A patent/JP6743417B2/ja not_active Expired - Fee Related
• 2017
  • 2017-01-18 DE DE112017001037.3T patent/DE112017001037T5/de not_active Withdrawn
  • 2017-01-18 WO PCT/EP2017/050986 patent/WO2017148611A1/en active Application Filing

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