JP2009277429A - Secondary battery and on-vehicle secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery capable of eliminating deviation of an electrolytic liquid, in a short time. <P>SOLUTION: The secondary battery 10 is constructed of a wound body 20, a positive electrode current collector 24 which bundles a plurality of current collector leads 21 extended from a positive electrode 16, a negative electrode current collector 39 which bundles a plurality of current collector leads 21 extended from a negative electrode 17, and a battery can 13 to house these. A winding core 15 is a hollow core and a liquid permeable body through which an electrolytic liquid 60 can pass, and at least one of one end and the other end has electrolytic liquid passages 41, 42 formed between the current collectors 24, 39. As a result, since the electrolytic liquid passages 41, 42 are installed and the hollow core is used for the winding core 15, the electrolytic liquid 60 can be made to flow easily into the winding core 15. Since the electrolytic liquid 60 can be made to flow easily into the winding core 15, the electrolytic liquid 60 can be supplied rapidly in the wound body 20, and deviation in the electrolytic liquid 60 can be eliminated, in a short time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a secondary battery, particularly a secondary battery suitable for in-vehicle use.

  Secondary batteries that can be used repeatedly by charging are used in hybrid vehicles and fuel cell vehicles.

Conventionally, secondary batteries having various shapes have been proposed (see, for example, Patent Document 1 and Patent Document 2).
JP 2003-22792 A (FIG. 1) Japanese Patent Laid-Open No. 2000-268877 (FIG. 4)

Patent document 1 is demonstrated based on the following figure.
FIG. 9 is a diagram for explaining a basic configuration of the technique according to Patent Document 1. A battery can 101 of the battery 100 includes a cylindrical negative electrode 102 and a gas-permeable membrane on a contact surface between the negative electrode 102 and the negative electrode 102. The bottomed cylindrical separator 103, the cylindrical positive electrode 104 surrounding the outer surface of the separator 103, and the electrolytic solution are accommodated.

According to the battery 100, the electrolytic solution in the battery 100 is accumulated in the lower part due to gravity, and a place where the electrolytic solution is not supplied may occur. Since the electrolytic solution is not supplied, the durability of the battery 100 is lowered.
A technique for eliminating such unevenness of the electrolyte will be described with reference to the following diagram.

  FIG. 10 is a diagram for explaining the basic configuration of the technique according to Patent Document 2. The secondary battery 110 includes a wound body 112 whose outer peripheral surface is fixed by an adhesive tape 111 and an upper end from one end of the wound body 112. An electrode lead 113 extending, an electrolyte solution holding portion 114 arranged so as to surround the electrode lead 113, an electrode lead 115 extending downward from the other end of the wound body 112, a bent portion 116 of the electrode lead 115, and a flange It is comprised from the electrolyte solution holding | maintenance part 117 arrange | positioned between the lower end parts of the rotation body 112. FIG.

  According to the secondary battery 110, the electrolyte solution is held by the electrolyte solution holding units 114 and 117, so that the electrolyte solution can be prevented from being insufficient, and the electrolyte solution can be supplied to the entire wound body 112. it can. Since the unevenness of the electrolyte in the secondary battery 110 can be eliminated, the durability of the secondary battery 110 can be improved.

  By the way, when the secondary battery is used in a vehicle or the like, the electrolyte in the secondary battery 110 is frequently biased due to vibrations received from the road surface or inclination of the vehicle body. When such a secondary battery 110 is used and a bias occurs, it takes time to eliminate the bias at the central portion 118 of the secondary battery 110 far from the electrolyte solution holding portions 114 and 117. Since it takes time to eliminate the unevenness of the electrolyte, the durability of the secondary battery is impaired.

  It is desired to provide a secondary battery that can eliminate the uneven electrolyte solution in a short time.

  An object of the present invention is to provide a secondary battery that can eliminate the unevenness of the electrolyte solution in a short time.

The invention according to claim 1 bundles a wound body in which a positive electrode, a negative electrode, and a separator are wound around a core, and a plurality of current collecting leads extended from the positive electrode and supports one end of the core. A positive electrode current collector, a negative electrode current collector that bundles a plurality of current collector leads extending from the negative electrode and supports the other end of the winding core, and a wound body, a positive electrode current collector, and a negative electrode current collector In a secondary battery consisting of a battery can for storing
The winding core is a hollow core and is a permeable liquid through which an electrolytic solution can pass, and at least one of the one end and the other end is provided with an electrolytic solution flow channel through which the electrolytic solution can flow. It is characterized by being.

  The invention according to claim 2 is characterized in that the winding core is partially disposed at an axial end portion of the wound body.

  The invention according to claim 3 is characterized in that the winding core is provided with a plurality of through holes penetrating from the inner peripheral surface to the outer peripheral surface.

  In the invention according to claim 4, the battery can includes a bottomed cylindrical body including a bottom part and a wall part raised from the periphery of the bottom part, and the wall part also serves as a mounting surface on which the horizontal part is placed, It is characterized in that it is placed horizontally so that the axis of the winding core is at a predetermined angle with respect to the horizontal axis.

  The invention according to claim 5 is characterized in that the secondary battery according to claim 1, 2 or 3 is used by being mounted on a vehicle.

In the invention which concerns on Claim 1, the electrolyte flow path which can flow electrolyte solution between the current collectors with the winding core is provided. The electrolytic solution flows from the electrolytic solution flow path into the winding core, and then flows from the inner peripheral surface of the winding core toward the outer peripheral surface.
By providing an electrolyte flow path and using a hollow core as the winding core, the electrolyte can easily flow into the winding core. Since the electrolyte can easily flow inside the winding core, the electrolyte can be rapidly supplied to the wound body, and the unevenness of the electrolyte can be eliminated in a short time.

  In the invention which concerns on Claim 2, a winding core is partially arrange | positioned at the axial direction edge part of a winding body. The winding core is partially disposed at the end of the wound body, and no winding core is disposed at the center. In the portion where the winding core is not disposed, the electrolytic solution is directly supplied to the wound body. Since there is no time to pass through the winding core, the electrolytic solution can be supplied to the wound body in a shorter time.

  Further, a step is formed between the end of the winding core and the wound body by partially disposing the winding core. By forming the step, the electrolytic solution easily stays. When the electrolytic solution is easily retained, the supply of the electrolytic solution to the wound body is further promoted.

  In the invention which concerns on Claim 3, the through-hole penetrated from the inner peripheral surface to the outer peripheral surface is provided in the winding core. A part of the electrolyte flowing in the winding core is supplied to the wound body through the through hole. Since it is directly supplied to the winding body through the through hole, the electrolytic solution can be supplied to the winding body in a shorter time.

  In the invention according to claim 4, the winding core is placed horizontally so as to be horizontal. It becomes easy to let electrolyte solution pass through the inside of a winding core by placing horizontally. By facilitating the passage of the electrolytic solution, the electrolytic solution can be evenly distributed in the wound body.

  In the invention which concerns on Claim 5, a secondary battery is mounted and used for a vehicle. Secondary batteries used in vehicles tend to be biased where electrolyte is supplied due to vibrations received from the road surface. Since the electrolytic solution can easily flow inside the winding core, the electrolytic solution can be supplied to the wound body in a short time, so that it is possible to easily eliminate the unevenness of the electrolytic solution.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view of a secondary battery according to the present invention. The secondary battery 10 includes a winding core 15 in a battery can 13 including a bottom 11 and a wall 12 raised from the periphery of the bottom 11. A winding body 20 (details will be described later) in which the positive electrode 16, the negative electrode 17 and the separator 18 are integrally wound around the center, a current collecting lead 21 extending from the tip of the positive electrode 16 to the upper part of the drawing, The holding metal fitting 22 arranged on the outer peripheral surface of the tip end portion of the electric lead 21 and a plurality of flow passage holes 23 that are welded to the holding metal fitting 22 together with the current collecting lead 21 and easily pass through the electrolytic solution are formed. The positive electrode current collector 24, the aluminum positive electrode lead 25 welded to the upper surface of the central portion of the positive electrode current collector 24, and the lower surface disposed so that the convex portion 26 contacts the central upper surface of the positive electrode lead 25. Lid 27 and the upper surface of this lower lid 27 An upper lid body 29 having a central portion formed in a trapezoidal cross section 28, an insulator 32 disposed on the outer periphery of the upper lid body 29 and the lower lid body 27, and extending from the tip of the negative electrode 17 to the lower part of the drawing. Current collector lead 33, presser fitting 34 disposed on the outer peripheral surface of the tip of current collector lead 33, skirt portion 35 welded together with presser fixture 34 and current collector lead 33, and the electrolyte easily pass through. And a negative electrode current collector 39 including a bottom surface portion 38 having a recess 37 in the center and a plurality of flow path holes 36 are accommodated.

The upper end of the winding core 15 is disposed with a gap with respect to the bottom surface of the positive electrode current collector 24. This gap is the upper electrolyte flow path 41 for flowing the electrolyte.
Similarly, the lower end of the winding core 15 is disposed so as to leave a gap with respect to the bottom surface of the negative electrode current collector 39. This gap is the lower electrolyte flow path 42 for flowing the electrolyte.
A method for manufacturing such a secondary battery 10 will be described in the following figures.

  FIG. 2 is a diagram for explaining the components of the wound body according to the present invention, and the core 15 shown in (a) can be made of polypropylene or polyethylene. It is a liquid that has a large number of fine holes and allows the electrolyte to pass through. The winding core 15 has, for example, a hexagonal hollow portion 45 as shown in (b) of FIG.

The positive electrode 16 shown in (c) includes, for example, a positive electrode body 46 made of an aluminum foil having a film thickness of 20 μm, a slurry 47 applied to a part of both surfaces of the positive electrode body 46, and a portion where the slurry 47 is not formed. It comprises a plurality of leads 48 formed by punching.
Slurry 47 is formed by dispersing in N-methylpyrrolidone having an average particle diameter of 6 μm, 90% by weight of nickel-lithium manganate powder, 5% by weight of acetylene black, and 5% of vinylidene fluoride resin. Is done.

  The separator 18 shown in (d) is made of, for example, polypropylene or polyethylene and has a microporous film.

The negative electrode 17 shown in (e) includes, for example, a negative electrode body 51 made of copper foil having a film thickness of 14 μm, a slurry 52 applied to a part of both surfaces of the negative electrode body 51, and a portion where the slurry 52 is not formed. It comprises a plurality of leads 53 formed by punching.
The slurry 52 is dispersed in N-methylpyrrolidone so that the average particle diameter is 10 μm, the non-graphitizable carbon powder is 90% by weight, the carbon fiber is 1.5% by weight, and the vinylidene fluoride resin is 8.5%. Formed.

  FIG. 3 is a diagram for explaining a method for producing a wound body according to the present invention. As shown in FIG. 3A, the separator 18, the negative electrode 17, the separator 18, and the positive electrode 16 are stacked in this order from below and wound around one end. A wick 15 is placed. When the positive electrode 16, the negative electrode 17 and the separator 18 are wound around the winding core 15, as shown in FIG. 5B, the wound body 20 in which the positive electrode 16, the negative electrode 17 and the separator 18 are integrally wound. Is manufactured.

FIG. 4 is an explanatory view when the negative electrode current collector according to the present invention is welded to the inside of the battery can, and the negative electrode current collector 39 is welded to the battery can 13 by projection welding.
That is, one welding electrode 55 is passed through the hollow portion 45 of the winding core 15 and lowered to a position where it comes into contact with the concave portion 37 of the negative electrode current collector 39. The other welding electrode 56 is disposed below the tip surface 57 from the bottom 11 of the battery can 13. At this time, the battery can 13 is supported using the support rod 58.

Next, a voltage is applied. The negative electrode current collector 39 can be welded to the battery can 13 by the resistance heat at this time.
Weld several places in the same way. Alternatively, welding is performed linearly along the tip surface 57.

After the negative electrode current collector 39 is welded to the battery can 13, the electrolyte is injected and the lid bodies (the upper lid body 29 and the lower lid body 27 in FIG. 1) are arranged.
As the electrolytic solution, for example, a solution obtained by dissolving 1 mol / L LiPF ₆ (lithium salt) in a mixed solvent of ethylene carbonate and ethyl methyl carbonate can be used.

  The front end surface 57 of the skirt portion 35 of the negative electrode current collector 39 is welded to the bottom portion 11 of the battery can 13. The outer diameter of the skirt portion 35 can be increased so as to be substantially equal to the inner diameter of the battery can 13. As a result, the junction area increases and the strength of the secondary battery 10 can be increased.

Next, the operation of the secondary battery having the above configuration will be described.
FIG. 5 is an explanatory view of the operation of the secondary battery according to the present invention, and the negative electrode current collector 39 will be described as an example. The electrolyte solution 60 filled in the battery can 13 passes through the hollow portion 45 of the winding core 15 as shown by the arrow (1), and flows in the hollow portion 45 in the left direction of the drawing. The electrolyte solution in the hollow portion 45 flows through fine holes from the inner peripheral surface of the winding core 15 toward the outer peripheral surface as indicated by an arrow (2).

  The electrolyte solution 60 that has flowed through the fine holes from the inner peripheral surface of the winding core 15 toward the outer peripheral surface flows on the surfaces of the positive electrode 16, the negative electrode 17, and the separator 18, as indicated by (b) arrow (3). . In the wound body 20, the positive electrode 16, the negative electrode 17, and the separator 18 are wound around the winding core 15. Therefore, the electrolyte flowing from the inner peripheral surface of the winding core 15 toward the outer peripheral surface is the winding body 20. It flows toward the outer periphery on the surface.

  Returning to (a), the winding core 15 is provided with a lower electrolyte channel 42 through which the electrolyte 60 can flow between the negative electrode current collector 39. The electrolyte 60 flows through the lower electrolyte flow path 42 and into the winding core 15. By providing the lower electrolyte flow path 42 and using a hollow core for the winding core 15, the electrolyte 60 can easily flow into the winding core.

Since the electrolytic solution can easily flow inside the winding core 15, the electrolytic solution 60 can be quickly supplied to the wound body 20, and the unevenness of the electrolytic solution 60 can be eliminated in a short time.
The same applies to the positive electrode current collector (positive electrode current collector 24 in FIG. 1) side.

  The secondary battery 10 according to the present invention can be mounted on a vehicle and used as the in-vehicle secondary battery 61.

  The in-vehicle secondary battery 61 tends to be biased in the place where the electrolytic solution 60 is supplied due to vibration received from the road surface or the like. Since the electrolyte solution 60 can be easily flowed into the winding core 15, the electrolyte solution 60 can be supplied to the wound body 20 in a short time, so that it is possible to easily eliminate the unevenness of the electrolyte solution 60. It is.

Another embodiment of the secondary battery according to the present invention will be described below.
FIG. 6 is a diagram showing another embodiment of FIG. 1, and the same elements as those in FIG.
Instead of the winding core 15 of FIG. 1, short winding cores 63, 63 are partially provided at the axial end of the wound body 20, and a space 64 is formed between the winding core 63 and the winding core 63.

  In the hollow portion 64 where the winding core 63 is not disposed, the electrolytic solution is directly supplied to the wound body 20. Since there is no time to pass through the fine holes of the winding core 63, the electrolyte can be supplied to the wound body 20 in a shorter time.

  Further, by disposing the winding cores 63 and 63 partially, steps 65 and 65 are formed between the ends of the winding cores 63 and 63 and the wound body 20. By forming the steps 65 and 65, the electrolytic solution easily stays in the cavity 64. When the electrolytic solution is easily retained, the supply of the electrolytic solution to the wound body 20 is further promoted.

FIG. 7 is a view showing still another embodiment of FIG. 1, and a winding core 67 provided with a plurality of through holes 66 penetrating from the inner peripheral surface to the outer peripheral surface is used.
A part of the electrolyte flowing in the winding core 67 is supplied to the wound body 20 through the through hole 66. It is supplied directly to the wound body 20 through the through hole 66. That is, the electrolyte solution can be supplied to the wound body in a shorter time because it does not pass through the fine holes of the winding core 67.

FIG. 8 is an explanatory diagram when the secondary battery according to the present invention is used horizontally, and the secondary battery 10 also serves as a mounting surface on which the wall portion 12 of the battery can 13 is placed on a horizontal plane. The core 15 is horizontally placed so that the axis 68 of the core 15 is at a predetermined angle with respect to the horizontal axis.
Specifically, when the axis 68 is parallel to the horizontal axis and 0 ° and the clockwise direction is the positive direction, the angle formed by the axis 68 with respect to the horizontal axis is −15 ° ≦ θ ≦ 15 °. Is desirable.

  By placing it horizontally, the electrolytic solution 60 can be easily passed through the core 15. By making the electrolytic solution 60 easy to pass, the electrolytic solution 60 can be evenly distributed in the wound body 20.

  In addition, although the secondary battery which concerns on this invention was applied to the vehicle in embodiment, it is applicable also to an airplane, a ship, and household appliances, and a use is not limited to these things.

  The secondary battery of the present invention is suitable for a secondary battery mounted on a vehicle.

FIG. 1 is a cross-sectional view of a secondary battery according to the present invention. It is a figure explaining the component of the winding body which concerns on this invention. It is a figure explaining the manufacturing method of the winding body concerning the present invention. It is explanatory drawing at the time of welding the negative electrode collector which concerns on this invention inside a battery can. It is action | operation explanatory drawing of the secondary battery which concerns on this invention. It is another Example figure of FIG. FIG. 3 is a diagram showing still another embodiment of FIG. 1. It is explanatory drawing at the time of using the secondary battery which concerns on this invention horizontally. It is a figure explaining the basic composition of the art concerning patent documents 1. It is a figure explaining the basic composition of the art concerning patent documents 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Bottom part, 12 ... Wall part, 13 ... Battery can, 15, 63, 67 ... Core, 16 ... Positive electrode, 17 ... Negative electrode, 18 ... Separator, 21, 33 ... Current collection lead, 24 DESCRIPTION OF SYMBOLS ... Positive electrode collector, 39 ... Negative electrode collector, 41, 42 ... Electrolyte flow path, 45 ... Hollow part, 60 ... Electrolyte, 61 ... In-vehicle secondary battery, 66 ... Through-hole.

Claims (5)

A wound body in which a positive electrode, a negative electrode, and a separator are wound around a winding core; a positive current collector that bundles a plurality of current collecting leads extending from the positive electrode and supports one end of the winding core; and the negative electrode A negative electrode current collector for bundling a plurality of current collector leads extended from and supporting the other end of the winding core, and a battery can for storing the wound body, the positive electrode current collector, and the negative electrode current collector; In the secondary battery consisting of
The winding core is a hollow core and is a permeable liquid through which an electrolytic solution can pass, and at least one of the one end and the other end is provided with an electrolytic solution flow channel through which the electrolytic solution can flow. A secondary battery characterized by that.   The secondary battery according to claim 1, wherein the winding core is partially disposed at an axial end portion of the wound body.   The secondary battery according to claim 1, wherein the winding core is provided with a plurality of through holes penetrating from the inner peripheral surface to the outer peripheral surface.   The battery can includes a bottomed cylindrical body composed of a bottom portion and a wall portion raised from the periphery of the bottom portion, the wall portion also serving as a mounting surface on which a horizontal surface is placed, and the axis of the winding core is horizontal The secondary battery according to claim 1, wherein the secondary battery is placed horizontally so as to have a predetermined angle with respect to the shaft.   The in-vehicle secondary battery, wherein the secondary battery according to claim 1, 2 or 3 is used by being mounted on a vehicle.

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