JP2005203192A - Laminated secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated secondary battery wherein a radiator fin securing sufficient heat radiation efficiency without interrupting an air blowing passage for heat radiation is integrally formed with an electrode lead. <P>SOLUTION: This laminated secondary battery is provided with electrode members 21, 31 provided with two of outer terminals 21a, 21c, 31a and 31c to both end parts, formed in an approximately L shape and wherein outer terminals are connected with tabular terminal connection parts 21b, 31b. The outer terminals 21a, 31a are connected with each electrode part 2, 3 of a battery component 1, and the electrode members 21, 31 are connected with positive/negative electrodes. Each of outer terminals 21a, 21c, 31a and 31c can function as an electrode terminal, and can also serve as a radiator fin. The terminal connection parts 21b, 31b are arranged on an end face 4 of the battery element in parallel, and have a function transmitting heat generated by the battery component 1 to the outer terminal 21a, 21c, 31a and 31c. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminate-type secondary battery, and particularly relates to improvement of heat dissipation in a laminate-type secondary battery.

  In the battery disclosed in Patent Document 1, the laminated electrode group is housed in an outer case formed by a pair of laminate sheets whose periphery is welded and sealed, and the positive electrode lead and the negative electrode lead are taken out from one end of the outer case. Has a structure. The positive electrode lead and the negative electrode lead are welded and sealed with a laminate sheet via a resin sheet, and the bonding strength of the welded seal in the electrode lead is ensured.

  As other related technologies, Patent Documents 2 to 5 are disclosed.

JP 2000-285904 A (FIG. 1) JP 2002-319388 A JP 2001-143769 A Japanese Patent Laid-Open No. 2001-6651 JP 11-339757 A

  However, in the battery structure disclosed in Patent Document 1, the laminated electrode group is hermetically sealed and stored in a laminate sheet whose periphery is welded and sealed. Only the positive / negative lead led out to the outside must serve as the function of the heat radiating fin, and there is a problem that sufficient heat radiation efficiency cannot be obtained.

  In particular, when it is necessary to install a battery in a limited space, such as when a plurality of batteries are stacked to form an assembled battery, the heat generation of the battery itself due to the stacked electrode group cannot be ignored, and sufficient heat dissipation is possible. If this cannot be ensured, there is a risk that problems such as deterioration of battery characteristics accompanying a rise in temperature of the laminated electrode group may be caused.

  Specifically, in recent years, when secondary batteries such as lithium ion batteries and nickel metal hydride batteries are mounted as batteries for hybrid vehicles and electric vehicles, the secondary batteries are externally mounted to ensure high output voltage and energy density. Increasing use is being made of assembled batteries that are stacked and housed in a case. When these secondary batteries are charged and discharged, heat generation due to chemical reaction between positive and negative electrode materials and heat generation such as Joule heat due to current flowing through the resistance component cannot be avoided. Since it is laminated in a limited storage space with a high density, the generated heat has the property of being easily trapped. There is an urgent need to improve the heat dissipation characteristics of these assembled batteries.

  In order to increase the heat dissipation of the electrode lead drawn out to the outside, it is conceivable to increase the surface area of the electrode lead, and measures such as increasing the size of the electrode lead itself or making the surface of the electrode lead uneven are also conceivable. . However, these measures are problematic because it is impossible to secure a sufficient ventilation path for heat dissipation due to the physique of the electrode leads, and there is a risk of increasing the manufacturing cost when processing into a concavo-convex shape.

  The present invention has been made in order to solve at least one of the problems of the prior art, and a radiation fin that secures sufficient heat radiation efficiency without blocking a ventilation path for heat radiation is formed integrally with an electrode lead. An object of the present invention is to provide a laminated secondary battery.

  In order to achieve the above object, a laminated secondary battery according to claim 1 is configured such that a battery element is hermetically sealed in an exterior body made of a laminate sheet, and is drawn out from the positive / negative electrode of the battery element to the outside of the exterior body. At least one of the pair of external terminals is composed of a plurality of terminal groups, and at least one terminal of the plurality of terminal groups is an electrode via a terminal connection portion that runs parallel to the end face of the battery element in the exterior body. It is connected to.

  In the laminate type secondary battery according to claim 1, at least one of the positive / negative external terminals is constituted by pulling out a plurality of terminal groups of two or more terminals from the exterior body. And at least 1 terminal is connected between the electrode of the battery element accommodated in the exterior body through the terminal connection part which runs in parallel with the end surface of a battery element among several terminal groups. Here, the end face refers to a face formed by laminating a positive / negative electrode and a separator sandwiched between the electrodes.

  As a result, the external terminal, which is an electrode terminal, is configured to include a plurality of terminals, and when configuring an assembled battery or when connecting to an external circuit, the connection position between the external terminals and the power supply from the external terminal The surrounding position of the path can be freely selected, and a flexible arrangement configuration of the secondary battery can be realized.

  In addition, the external terminal plays the role of a heat radiating fin. When the external terminal constituting at least one of the electrodes is composed of a plurality of terminals, it has a plurality of heat radiating fins and can efficiently radiate heat. It becomes. The heat dissipation performance can be improved.

  Furthermore, since the terminal connection part that connects the electrode of the battery element and the external terminal runs in parallel with the end face of the battery element in the exterior body, the heat of the battery element generated by charging / discharging can be efficiently propagated to the terminal connection part. Can do. The heat propagated to the terminal connection portion can be easily dissipated from a plurality of terminals drawn to the outside. The heat generated in the battery element can be propagated to the external terminal not only from the electrode of the battery element but also from the end face where the terminal connection portion runs in parallel, and can be efficiently radiated to the outside of the exterior body.

  The laminate type secondary battery according to claim 2 is the laminate type secondary battery according to claim 1, wherein the terminal connection portion has a flat plate shape facing the end face of the battery element. To do. As a result, the terminal connecting portion that connects the electrode of the battery element and the external terminal has a flat plate shape and runs parallel to the end surface of the battery element. The area facing the element can be sufficiently secured, and the heat generated from the battery element can be efficiently propagated to the terminal connection portion.

  A laminate type secondary battery according to claim 3 is the laminate type secondary battery according to claim 1 or 2, wherein each of the pair of external terminals includes a plurality of terminal groups. The parts are provided to run in parallel on different end faces of the battery element. As a result, the terminal connecting portions connected to each of the positive / negative external electrodes can run in a wide range over the entire surface of the battery element without interfering with each other. The heat can be radiated and the heat radiation can be improved.

  A laminate type secondary battery according to claim 4 is the laminate type secondary battery according to claim 1, wherein one terminal of the plurality of terminal groups is an electrode terminal, and at least one other terminal is a radiation fin. It is characterized by being. Moreover, the laminate type secondary battery according to claim 5 is the laminate type secondary battery according to claim 4, wherein the electrode terminal and the heat radiating fin drawn out from the exterior body are respectively different end sides of the exterior body. It is located in. Thereby, a radiation fin can be arrange | positioned on the edge side different from the edge side where the electrical path connected to the positive / negative electrode of a secondary battery is arrange | positioned. The heat radiation fins can be drawn out to the end portion where there is no electric path or the like and the path of the cooling air is not restricted, and the heat radiation efficiency can be improved. Here, the end side refers to the outer peripheral portion of the end face of the battery element. The electrode terminal and the heat radiating fin are drawn out from the exterior body at the outer periphery of the battery element.

  According to the present invention, the area of the heat radiating plate for ensuring heat dissipation can be secured by the terminal connection portion inside the exterior material, and can be secured by a plurality of terminal groups outside the exterior material, It is possible to provide a laminate type secondary battery in which heat radiation fins that ensure sufficient heat radiation efficiency are formed integrally with an electrode lead.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the laminated secondary battery of the present invention will be described in detail below with reference to the drawings based on FIGS. The battery element 1 shown below has a configuration formed by winding a rectangular long battery sheet in which a positive electrode material sheet and a negative electrode material sheet are laminated via a separator. A positive / negative electrode material sheet is extended and arranged on each long side portion of the battery sheet to form positive / negative electrode portions 2 and 3.

  In the laminated secondary battery according to the first embodiment shown in FIG. 1, substantially L-shaped electrode members 21 and 31 are provided. Both ends of the substantially L-shape that are orthogonal to each other constitute external terminals 21a and 21c, 31a and 31c. Each of the positive / negative external terminals has two terminals.

  The external terminals 21a and 21c and the external terminals 31a and 31c are connected by flat terminal connection portions 21b and 31b. External terminals 21a and 21c, 31a and 31c, and terminal connecting portions 21b and 31b are formed along the end sides of wound battery element 1.

  The electrode parts 2 and 3 of the battery element 1 to which the external terminals 21a and 31a are connected are configured by winding a plurality of layers of only positive / negative electrode sheets without separators and opposite electrode sheets. ing. In the electrode portions 2 and 3, the positive / negative electrode sheets need to be connected to the external terminals 21 a and 31 a with low resistance, and the electrode sheets that are wound and stacked are in pressure contact and are in close contact with each other. By connecting the external terminals 21a and 31a to the close contact positions, the long battery element 1 is connected to the external terminals 21a and 31a with a low resistance at every circumferential distance to be wound, and power is evenly extracted. It is.

  The central portion of the battery element 1 having a structure in which a three-layer structure of a positive / negative electrode sheet and a separator is wound is formed with a thickness as compared with the electrode portions 2 and 3 that are press-contacted. In addition, as shown in FIG. 2, the battery element 1 is sandwiched between a pair of laminate sheets 5 from both end surfaces after the electrode members 21 and 31 are connected, and the laminate sheet is sealed between the peripheral edges of the battery element 1. It is configured to be hermetically sealed. The external electrodes 21a and 21c, 31a and 31c are configured to be drawn out from between the laminated sheets 5 to be sealed. Therefore, the external electrodes 21a and 21c, 31a and 31c need to be disposed at a substantially central portion in the width direction of the battery element 1 which is wound and has a width and thickness. External terminals 21a and 21c, 31a and 31c drawn out at substantially the center in the width direction of battery element 1 and terminal connection parts 21b and 31b arranged in parallel with battery element end face 4 of battery element 1 are battery elements. 1 are connected with a structure bent along a width and thickness of 1.

  In the secondary battery (FIG. 2) in which the positive / negative electrodes are respectively drawn out as the external terminals from the adjacent two end sides of the secondary battery, one of the terminals is used for the electrode, The other electrode can function as a heat radiating fin.

  FIG. 3 shows a state in which the secondary battery of FIG. 2 is stacked with the opposite surfaces alternately reversed. Two types of external terminals 21a and 31a, 21c and 31c facing each other between adjacent secondary batteries serve as counter electrode terminals. In FIG. 3, the external terminals 21a and 31a are terminals for electrode extraction. A configuration in which secondary batteries 21a and 31a, which are alternately drawn out for each battery from two opposite sides of the battery, are alternately connected to each other by the connection plate 6 and connected in series. is there. It is a common connection configuration in an assembled battery used for an application requiring a high voltage level such as a hybrid vehicle or an electric vehicle.

  The external terminals 21c and 31c that are not used as electrodes are arranged at opposite ends of one end side of the secondary battery and are alternately opposed to each other. The external terminals 21c and 31c can also be used as dedicated heat radiating fins in addition to being able to be alternately connected to the left and right ends by a connection plate. Since the external terminals 21c and 31c are arranged at both ends while securing the air flow path of the cooling air at the center of the edge without blocking the whole area of the one edge of the secondary battery, the external terminals 21c and 31c are efficient against the flow of the cooling air. Heat dissipation is performed.

  Here, the external terminals 21c and 31c can ensure the same heat dissipation effect when they are used as electrodes by connecting adjacent terminals with a connection plate (not shown). Needless to say, the external terminals 21a and 31a used as electrodes also have the same effect as heat dissipating fins.

  In addition, the plate-like terminal connection portions 21b and 31b connecting the external terminals 21a and 31a and 21c and 31c run in parallel to the battery element end face 4, and further when configuring an assembled battery or the like. The heat generated in the battery element 1 is efficiently propagated to the terminal connection portions 21b and 31b in response to contact with and press on the battery element end face 4 by pressing the stacked secondary battery or the like, and the external terminal 21a. And 31a, 21c and 31c are efficiently dissipated.

  Note that the cooling air blowing direction is not limited to the direction shown in FIG. 3 and may be a direction in which the external terminals 21a and 31a, 21c and 31c can be cooled, such as a direction in which the terminal connection portions 21b and 31b run in parallel. Needless to say, the direction may be any direction.

  In the modification of 1st Embodiment shown in FIG. 4, it is the structure provided with the external terminals 21d and 31d which have a some notch as a radiation fin. As a result, the surface areas of the external terminals 21d and 31d as the heat radiating fins are increased, and a cooling air blowing path that directly hits the external terminals 21d and 31d is secured, so that the heat radiation efficiency can be improved.

  It should be noted that the direction, shape, number, etc. of the notches are not limited to the modification shown in FIG. 4, and it is needless to say that various directions, shapes, numbers, etc. are possible in a mode that provides a heat dissipation effect. .

  Further, in the laminated secondary battery of the second embodiment shown in FIG. 5, electrode members 22 and 32 are provided instead of the electrode members 21 and 31 in the first embodiment.

  Instead of the external terminals 21c and 31c drawn out from the same end side of the secondary battery, the external terminals 22c and 32c are drawn out from the respective two opposite sides of the secondary battery. Further, instead of the external terminals 21c and 31c being drawn out as one terminal at the end of the battery edge, each of the external terminals 22c and 32c has two terminals drawn out at both ends of the battery edge. Configured. Further, the two terminals of the external terminals 22c and 32c are connected by the terminal connection portions 22b and 32b. For this reason, the terminal connection portions 22b and 32b run parallel to the battery element carrying end face 4 and are connected to the external terminals 22c and 32c. Is arranged over the entire end edge from which is drawn. In addition, the external terminals 22a and 32a connected to the electrode parts 2 and 3 of the battery element 1 have the same configuration as the external terminals 21a and 31a, and have the same functions and effects.

  As a result, the external terminals 22c and 32c that function as heat radiating fins are drawn out from different end sides and arranged over the entire end sides, so that a heat radiating fin having a sufficient heat radiating area can be configured. Since the cooling air flow path is also secured, the cooling efficiency of the heat radiation fins can be secured. Moreover, since the distance which runs parallel to the battery element end surface 4 can be set long also about the terminal connection parts 22b and 32b, the opposing area which opposes the battery element end surface 4 can be increased, and heat dissipation efficiency is improved. be able to.

  Furthermore, in the laminate type secondary battery of the third embodiment shown in FIG. 6, electrode members 23 and 33 are provided instead of the electrode members 22 and 32 in the second embodiment.

  In place of the terminal connection portions 22b and 32b configured to run in parallel only on one end surface of the battery element end surface 4, in the electrode members 23 and 33, the terminal connection portions 23b and 33b are respectively opposite to each other. It is configured to run parallel to the end face. Since only one terminal connection portion exists on one end surface, the terminal connection portions 23b and 33b can be flat plates covering the entire end surface.

  In addition, instead of the external terminals 22c and 32c in which two terminals are drawn out from each of the two opposing edges of the secondary battery to both ends of the edge, the external terminals 23c, 33c is drawn out.

  The external terminals 23a and 33a have the same configuration as the external terminals 22a and 32a, and have the same functions and effects.

  As a result, the external terminals 23c and 33c that function as heat radiating fins are drawn from different end sides and arranged over the entire end sides, so that a heat radiating fin having a sufficient heat radiating area can be configured. . Moreover, the terminal connection parts 23b and 33b can be made into the whole region of the battery element end surface 4, the opposing area facing the battery element end surface 4 can be increased to the maximum, and the heat radiation efficiency can be improved.

  As described above in detail, according to the laminated secondary battery according to the present embodiment, the electrode terminals are external terminals 21a and 21c or d, 31a and 31c or d, 22a and 22c, 32a and 32c, 23a and 23c, 33a, and 33c are configured to include two or more terminals. When an assembled battery is configured by the secondary battery, and when the secondary battery is connected to an external circuit, the external terminals are connected to each other. The connection position and the surrounding position of the power supply path from the external terminal can be freely selected, and a flexible arrangement configuration can be realized.

  Moreover, since the external terminal plays the role of a heat radiating fin, it has two or more heat radiating fins, and the heat radiating performance can be improved.

  Furthermore, since the terminal connection portions 21b to 23b and 31b to 33b run in parallel to the battery element end face 4, the heat of the battery element 1 generated by charging / discharging efficiently propagates to the terminal connection portion, and from two or more terminals. Heat is easily dissipated. The heat generated in the battery element 1 can be propagated to the external terminal not only from the electrode parts 2 and 3 of the battery element 1 but also from the end face where the terminal connection part runs in parallel, and can be efficiently radiated to the outside.

  In addition, since the terminal connection portion has a flat plate shape and runs parallel to the battery element end face 4, heat generated from the battery element 1 is efficiently propagated to the terminal connection portion, and the battery size is used when configuring an assembled battery or the like. When the secondary battery is pressed for the purpose of making the battery compact or reducing the internal resistance of the battery element, etc., the terminal connection portion can be efficiently brought into contact with or pressed against the battery element end face 4, and the terminal connection portion can dissipate heat. The effect can be enhanced.

  Further, the terminal connecting portions 23b and 33b can run in a wide range over the entire area of the battery element end face 4 without interfering with each other, and can dissipate the battery element 1 from a plurality of directions. It is possible to improve the performance.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various improvements and modifications can be made without departing from the spirit of the present invention. For example, the present invention does not depend on the battery type. The same applies to battery types other than lithium ion batteries and nickel metal hydride batteries.

It is a figure which shows the attachment state of an external terminal in the lamination type secondary battery of 1st Embodiment. It is a figure which shows the external appearance of the lamination type secondary battery of 1st Embodiment. It is a figure which shows the state which laminated | stacked the lamination type secondary battery of 1st Embodiment. It is a figure which shows the modification of an external terminal shape in the lamination type secondary battery of 1st Embodiment. It is a figure which shows the attachment state of an external terminal in the lamination type secondary battery of 2nd Embodiment. It is a figure which shows the attachment state of an external terminal in the lamination type secondary battery of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery element 2, 3 Electrode part 4 Battery element end surface 5 Laminate sheet 6 Connection board 21 thru | or 23, 31 thru | or 33 Electrode member 21a thru | or 23c, 21c thru | or 23c, 21d, 31a thru | or 33a, 31c thru | or 33c, 31d External terminal 21b thru | or 23b, 31b to 33b Terminal connection part

Claims (5)

In a laminate type secondary battery in which a battery element is hermetically sealed in an exterior body made of a laminate sheet,
At least any one of a pair of external terminals drawn out from the positive / negative electrode in the battery element to the outside of the exterior body is composed of a plurality of terminal groups,
At least one terminal of the plurality of terminal groups is connected to the electrode through a terminal connection portion that runs parallel to an end face of the battery element in the outer package.   The laminated secondary battery according to claim 1, wherein the terminal connection portion has a flat plate shape facing an end face of the battery element.   3. When each of the pair of external terminals is configured by the plurality of terminal groups, each terminal connection portion is provided in parallel with a different end face of the battery element. The laminated secondary battery as described.   2. The laminated secondary battery according to claim 1, wherein one terminal of the plurality of terminal groups is an electrode terminal, and at least one other terminal is a radiation fin.   5. The laminated secondary battery according to claim 4, wherein an end side of the exterior body from which the electrode terminal is pulled out is different from an end side of the exterior body from which the radiating fin is pulled out. 6. .

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