JP2010009978A - Electrode body gas discharge method of secondary battery and secondary battery structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode body gas discharge method of a secondary battery, discharging gas existing inside an electrode body of a secondary battery suitably out of the electrode body, and to provide a secondary battery structure. <P>SOLUTION: In the electrode body gas discharge method of a secondary battery, gas existing inside an electrode body 150 is discharged out of the electrode body 150 by increasing and decreasing pressure applied onto the electrode body 150 in a lamination direction X of a cathode 155, an anode 156 and a separator 157 of a secondary battery 100 having the electrode body 150 composed of a lamination of the cathode 155, the anode 156 and the separator 157. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for discharging gas existing inside an electrode body of a secondary battery to the outside of the electrode body, and a secondary battery structure.

  Secondary batteries such as lithium ion secondary batteries are attracting attention as power sources for portable devices and as power sources for electric vehicles and hybrid vehicles. However, when the secondary battery is discharged with a large current or overcharged, gas may be generated in the battery and the internal pressure of the battery may increase. If the battery internal pressure rises too much, there is a risk that the battery case will burst. In order to avoid such danger, many methods have been proposed in which a safety valve is provided in the secondary battery and gas is discharged to the outside by the operation of the safety valve (for example, see Patent Document 1).

JP 2006-40626 A JP 2000-90974 A JP 2003-331916 A

  In addition, in the process of manufacturing the secondary battery, gas may be generated along with the decomposition of the electrolytic solution when initial charging is performed. Various methods have been proposed for discharging the gas (see, for example, Patent Documents 2 and 3).

  Patent Document 2 discloses a method of discharging gas to the outside by performing a decompression process with the battery case opened after performing initial charging. Patent Document 3 discloses a method in which, after initial charging, a part of a battery case is opened, vacuum is evacuated at a pressure of 130 to 40000 Pa, and gas is discharged to the outside.

  By the way, the gas generated in the battery may stay in the electrode body (between the electrode and the separator). Due to the presence of the staying gas, the charge / discharge reaction is hindered, and the battery performance may be greatly deteriorated. However, in the method of Patent Document 1, even if gas is generated in the battery, the gas staying inside the electrode body cannot be discharged until the internal pressure of the battery reaches the valve opening pressure.

  Moreover, since the gas staying inside the electrode body (between the electrode and the separator) is difficult to escape, the gas staying inside the electrode body may not be discharged even if the safety valve operates. there were. Similarly, even in the methods of Patent Documents 2 and 3, the gas staying inside the electrode body (between the electrode and the separator) due to the initial charging may not be properly discharged to the outside of the electrode body. there were.

  In addition, a secondary battery installed as a power source for a portable device, a hybrid vehicle, etc., generates gas in the battery case even when it is left standing (resting state), and the inside of the electrode body (between the electrode and the separator) May stay. Since this gas is not generated in such a large amount that the safety valve is opened, in the method of Patent Document 1, the gas staying inside the electrode body (between the electrode and the separator) due to leaving (pause) , Could not be discharged outside the electrode body.

  The present invention has been made in view of the current situation, and an electrode body gas discharging method capable of appropriately discharging the gas existing inside the electrode body of the secondary battery to the outside of the electrode body, and the secondary An object is to provide a battery structure.

  The solution is to increase or decrease the pressure applied to the electrode body in the stacking direction of the positive electrode, negative electrode, and separator of a secondary battery having an electrode body formed by laminating a positive electrode, a negative electrode, and a separator. The electrode body gas discharge method of the secondary battery which discharges | emits the gas which exists in the inside to the exterior of the said electrode body.

  By increasing or decreasing the pressure applied to the electrode body in the stacking direction of the positive electrode, the negative electrode, and the separator, the gas staying inside the electrode body (between the negative electrode and the separator and between the positive electrode and the separator) Appropriately, it can be discharged outside the electrode body.

  In addition, the electrode body formed by stacking the positive electrode, the negative electrode, and the separator includes a wound electrode body formed by stacking the positive electrode, the negative electrode, and the separator and winding them. In the case of this wound electrode body, the direction (radial direction) orthogonal to the winding direction (circumferential direction) is the stacking direction.

  Moreover, the electrode body gas discharge | emission method of this invention is applicable with respect to the secondary battery with which it mounted | worn as power supplies, such as a portable apparatus and a hybrid vehicle. For example, when the secondary battery is left (rested) for a certain period of time or longer, there is a high possibility that gas is generated in the battery and the gas stays inside the electrode body. At this time, by applying the electrode body gas discharge method of the present invention, the gas staying inside the electrode body can be appropriately discharged outside the electrode body. Thereby, it can prevent that charging / discharging reaction is inhibited by the residence gas inside an electrode body, and can prevent that battery performance falls.

  Moreover, the electrode body gas discharge | emission method of this invention can be utilized in the manufacture process of a secondary battery. Specifically, by applying the electrode body gas discharge method of the present invention to the secondary battery that has been initially charged, the gas that has accumulated in the electrode body with the initial charging can be appropriately removed. Can be discharged outside.

  Furthermore, in the electrode body gas discharging method of the secondary battery, the secondary battery includes a battery case that houses the electrode body, and presses the battery case in a stacking direction of the positive electrode, the negative electrode, and the separator. It is preferable to use an electrode body gas discharging method for a secondary battery in which the pressing force applied to the battery case by the pressing means is increased or decreased to increase or decrease the pressure applied to the electrode body.

By increasing or decreasing the pressing force to the battery case by the pressing means, the pressure applied to the electrode body can be appropriately increased or decreased through the battery case. Thereby, the gas inside an electrode body can be discharged | emitted appropriately.
The number of secondary batteries (battery cases) pressed by the pressing means is not limited to one, but may be a plurality (for example, a plurality of secondary batteries arranged in a line in the stacking direction of the positive electrode, the negative electrode, and the separator). good.

  Moreover, it is preferable to increase / decrease the pressing force to a battery case in the range of 0.98 MPa-6.54 MPa. Thereby, the gas staying inside the electrode body can be reliably discharged.

  Furthermore, in the electrode body gas discharging method of the secondary battery, the pressing means is adjacent to and in contact with the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, An electrode body gas discharging method for a secondary battery, comprising: a dimension increasing / decreasing body capable of increasing / decreasing dimensions; and a first member and a second member for fixing the battery case and the dimension increasing / decreasing body in the stacking direction. Good.

  In the pressing means used in the electrode body gas discharge method of the present invention, the battery case and the size increasing / decreasing body are placed between the first member and the second member in the stacking direction of the positive electrode, the negative electrode, and the separator (hereinafter simply referred to as the stacking direction). The dimension of the dimension increasing / decreasing body can be increased or decreased in the stacking direction in a state of being sandwiched and fixed. Thereby, since the pressing force to a battery case can be increased / decreased appropriately, the pressure added to an electrode body can be increased / decreased appropriately through a battery case.

  The battery case sandwiched and fixed between the first member and the second member is not limited to one, but may be a plurality (for example, a plurality of battery cases arranged in a line in the stacking direction of the positive electrode, the negative electrode, and the separator). May be. Further, the size increasing / decreasing body is not limited to one, and a plurality of size increasing / decreasing bodies may be arranged. For example, when a plurality of secondary batteries are arranged in a line, one dimension increasing / decreasing body may be arranged between adjacent secondary batteries.

Moreover, a piezo element can be illustrated as a dimension increase / decrease body. By passing an alternating current through the piezo element, the piezo element is repeatedly expanded and contracted, and the size of the piezo element can be increased or decreased in the stacking direction of the positive electrode, the negative electrode, and the separator. As a result, the pressure applied to the battery case can be increased or decreased to increase or decrease the pressure applied to the electrode body.
Moreover, you may use the bag which self expand | swells and shrink | contracts by increase / decrease in hydraulic pressure or air pressure as a dimension increase / decrease body. By supplying and discharging oil (or air) to the bag, the bag is expanded and contracted, and the size of the bag can be increased or decreased in the stacking direction of the positive electrode, the negative electrode, and the separator.

  Alternatively, the electrode body gas discharging method of the secondary battery, wherein the pressing means includes a first member and a second member that fix the battery case sandwiched in a stacking direction of the positive electrode, the negative electrode, and the separator; A dimension increasing / decreasing body that is positioned between the battery case and at least one of the first member and the second member and that can increase / decrease its own dimension in the stacking direction of the positive electrode, the negative electrode, and the separator. The electrode body gas discharging method of the secondary battery is preferable.

  Alternatively, in the electrode body gas discharging method of the secondary battery, the pressing unit sandwiches the plurality of secondary batteries arranged in a line in the stacking direction of the positive electrode, the negative electrode, and the separator in the stacking direction. The first member and the second member to be fixed at the position, and between the battery case and at least one of the first member and the second member, or between the adjacent battery cases, the stacking direction Preferably, the electrode body gas discharge method of the secondary battery is provided with a dimension increasing / decreasing body capable of increasing / decreasing its own dimension.

  In the pressing means used in these gas discharge methods, the battery case and the dimension increasing / decreasing body are sandwiched between the positive electrode, the negative electrode, and the separator in the stacking direction (hereinafter also simply referred to as the stacking direction) by the first member and the second member. In the fixed state, the dimension of the dimension increasing / decreasing body can be increased or decreased in the stacking direction. Thereby, since the pressing force to a battery case can be increased / decreased appropriately, the pressure added to an electrode body can be increased / decreased appropriately through a battery case.

  Furthermore, in any one of the above secondary battery electrode body gas discharge methods, the battery case has a first side surface and a second side surface facing in the opposite direction, the first side surface and the second side surface, Each has an electrode region portion included in an electrode projection region obtained by projecting the electrode body onto the first side surface and the second side surface, and the size increasing / decreasing body is disposed in contact with the electrode region portion. The electrode body gas discharging method of the secondary battery is preferable.

According to this electrode body gas discharge method, the pressing force to the electrode region can be appropriately increased or decreased by increasing or decreasing the size of the dimension increasing or decreasing body. Thereby, since the pressure applied to an electrode body can be increased / decreased appropriately, the gas stagnating in an electrode body can be discharged | emitted appropriately outside the electrode body.
The pressure applied to the electrode region is preferably increased or decreased in the range of 0.98 MPa to 6.54 MPa. Thereby, the gas staying inside the electrode body can be reliably discharged.

  Furthermore, in any one of the above secondary battery electrode body gas discharge methods, the dimension increasing / decreasing body is a piezo element, and an alternating current is passed through the piezo element to stack the positive electrode, the negative electrode, and the separator in the stacking direction. It is preferable to use a secondary battery electrode gas discharge method that increases or decreases the size of the piezoelectric element.

  By passing an alternating current through the piezo element, the piezo element is repeatedly expanded and contracted, and the size of the piezo element can be increased or decreased in the stacking direction of the positive electrode, the negative electrode, and the separator. As a result, the pressure applied to the battery case can be increased or decreased to increase or decrease the pressure applied to the electrode body.

  Alternatively, in any one of the secondary battery electrode body gas discharge methods, the pressing means includes a first member and a second member that fix the battery case sandwiched in the stacking direction, and the first member. Reciprocating means for reciprocally moving the first member in the stacking direction, and reciprocating means for reciprocating the first member to increase / decrease the pressing force to the battery case. And good.

  According to the electrode body gas discharge method of the present invention, the pressing force to the battery case can be increased or decreased by reciprocating the first member in the stacking direction by the reciprocating means. Thereby, the pressure applied to an electrode body can be increased / decreased.

  The reciprocating means may be, for example, a cylinder using hydraulic pressure, water pressure, air pressure, or the like. By fixing a rod portion such as a hydraulic cylinder to the first member and reciprocating the rod portion in the stacking direction by hydraulic pressure or the like, the first member can be reciprocated in the stacking direction.

  As reciprocating means, a piston connected to a motor, an engine or the like through a connecting rod and a crankshaft can be cited. The piston is fixed to the first member, and the rotary motion by the motor, the engine, etc. is converted into the reciprocating motion in the stacking direction by the crankshaft and the connecting rod, so that the first member is reciprocated in the stacking direction together with the piston. It can be operated.

  Alternatively, the electrode body gas discharging method for the secondary battery may be a secondary battery electrode body gas discharging method for charging / discharging the secondary battery to increase or decrease the pressure applied to the electrode body.

  When the secondary battery is charged, the electrode body expands in the stacking direction of the positive electrode, the negative electrode, and the separator (hereinafter also simply referred to as the stacking direction), and then the electrode body contracts in the stacking direction when the secondary battery is discharged. . When the electrode body expands in the stacking direction by charging, the electrode body presses the inner surface of the battery case in the stacking direction. The reaction force from the battery case at this time can apply pressure to the electrode body in the stacking direction. Thereafter, when the electrode body contracts due to discharge, the force with which the electrode body presses the inner surface of the battery case is weakened, so that the pressure applied to the electrode body in the stacking direction is reduced.

  Therefore, by charging / discharging the secondary battery, the pressure applied to the electrode body in the stacking direction can be easily increased or decreased. Thereby, the gas staying inside the electrode body can be appropriately discharged to the outside of the electrode body.

  Furthermore, in the electrode body gas discharging method of the secondary battery, the battery case is sandwiched and fixed in the stacking direction of the positive electrode, the negative electrode, and the separator by the first member and the second member, It is good to use the electrode body gas discharge | emission method of the secondary battery which charges / discharges the said secondary battery.

  Expansion of the battery case pressed by the electrode body by charging the secondary battery while the battery case is sandwiched and fixed by the first member and the second member in the stacking direction of the positive electrode, the negative electrode, and the separator Can be prevented. As a result, the force applied to the battery case by the electrode body can be directly applied to the electrode body as a reaction force without escaping to the outside, so that the pressure applied to the electrode body can be increased.

Therefore, by increasing and decreasing the pressure applied to the electrode body, the secondary battery is charged and discharged in a state where the battery case is sandwiched and fixed between the first member and the second member. Thereby, the gas staying inside the electrode body can be more reliably discharged to the outside of the electrode body.
The battery case sandwiched and fixed between the first member and the second member is not limited to one, but may be a plurality (for example, a plurality of battery cases arranged in a line in the stacking direction of the positive electrode, the negative electrode, and the separator). May be.

  Furthermore, in the electrode body gas discharge method of the secondary battery, the battery case has a first side surface and a second side surface facing the opposite direction, and the first side surface and the second side surface are respectively In the state which has the electrode area | region part contained in the electrode projection area | region which projected the said electrode body on the said 1st side surface and the said 2nd side surface, and made the said 1st member and the said 2nd member contact the said electrode area | region part It is preferable that the secondary battery electrode body gas discharge method is to charge and discharge the secondary battery.

  According to this electrode body gas discharge method, the pressing force to the electrode region can be appropriately increased or decreased by charging and discharging the secondary battery. Thereby, since the pressure applied to an electrode body can be increased / decreased appropriately, the gas stagnating in an electrode body can be discharged | emitted appropriately outside the electrode body.

  Another solution is a secondary battery having an electrode body formed by laminating a positive electrode, a negative electrode, and a separator, and a battery case that accommodates the electrode body, and the above-mentioned in the stacking direction of the positive electrode, the negative electrode, and the separator. A pressing unit that presses the battery case, and a pressing unit that increases or decreases the pressure applied to the battery case by the pressing unit to increase or decrease the pressure applied to the electrode body.

The secondary battery structure of the present invention is a pressing means for pressing the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, and the pressing force applied to the battery case by the pressing means is increased or decreased and applied to the electrode body. A pressing means for increasing or decreasing the pressure is provided. By increasing or decreasing the pressing force to the battery case by the pressing means, the pressure applied to the electrode body can be appropriately increased or decreased through the battery case. Thereby, the gas inside an electrode body can be appropriately discharged | emitted outside the electrode body.
Note that the secondary battery constituting the secondary battery structure of the present invention is not limited to one, but a plurality (for example, a plurality of secondary batteries arranged in a line in the stacking direction of the positive electrode, the negative electrode, and the separator). May be.

  Further, in the above secondary battery structure, the pressing means is adjacent to and in contact with the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, and can increase or decrease its dimension in the stacking direction. It is good to make a secondary battery structure comprising: a size increasing / decreasing body, and a first member and a second member for fixing the battery case and the size increasing / decreasing body in the stacking direction.

  In the pressing means for the secondary battery structure according to the present invention, the battery case and the size increase / decrease body are stacked in the stacking direction of the positive electrode, the negative electrode, and the separator (hereinafter also simply referred to as the stacking direction) by the first member and the second member. The dimension of the dimension increasing / decreasing body can be increased / decreased in the stacking direction in a state of being sandwiched and fixed. Thereby, since the pressing force to a battery case can be increased / decreased appropriately, the pressure added to an electrode body can be increased / decreased appropriately through a battery case.

  The battery case sandwiched and fixed between the first member and the second member is not limited to one, but may be a plurality (for example, a plurality of battery cases arranged in a line in the stacking direction of the positive electrode, the negative electrode, and the separator). May be. Further, the size increasing / decreasing body is not limited to one, and a plurality of size increasing / decreasing bodies may be arranged. For example, when a plurality of secondary batteries are arranged in a line, one dimension increasing / decreasing body may be arranged between adjacent secondary batteries.

  Or it is the said secondary battery structure, Comprising: The said press means reciprocates the said 1st member in the said lamination direction with the 1st member and 2nd member which pinch | interpose and fix the said battery case in the said lamination direction. It is preferable that the secondary battery structure includes reciprocating means for moving the reciprocating means for reciprocating the first member to increase or decrease the pressing force to the battery case.

In the secondary battery structure of the present invention, the pressing force to the battery case can be increased or decreased by reciprocating the first member in the stacking direction by the reciprocating means. Thereby, the pressure applied to an electrode body can be increased / decreased.
As the reciprocating means, those described above can be used. Further, the battery case to be fixed by being sandwiched between the first member and the second member is not limited to one, and may be a plurality of battery cases.

Example 1
First, the secondary battery structure 200 of Example 1 will be described.
As shown in FIG. 1, the secondary battery structure 200 includes a secondary battery 100 and a pressing unit 300. Among these, as shown in FIGS. 2 and 3, the secondary battery 100 is a lithium ion secondary battery including a rectangular parallelepiped battery case 110, a positive external terminal 120, and a negative external terminal 130. As shown in FIG. 2, the battery case 110 has a first side surface 111 and a second side surface 112 facing in the opposite direction. The positive external terminal 120 and the negative external terminal 130 have a columnar shape, and external threads are formed on the outer peripheral surfaces thereof.

  The battery case 110 is made of metal, and has a battery case main body 117 having a rectangular parallelepiped housing portion 117b and a battery case lid 118 for closing the housing portion 117b of the battery case main body 117, as shown in FIG. . In the housing part 117b of the battery case main body 117, an electrode body 150, a non-aqueous electrolyte (not shown), and the like are housed.

  As shown in FIG. 5, the electrode body 150 has an oval cross section. As shown in FIG. 6, the electrode body 150 is a flat plate made by laminating and winding a sheet-like positive electrode 155, a negative electrode 156, and a separator 157. It is a round body. Among these, the positive electrode 155 includes a positive electrode current collector 151 (aluminum foil) and a positive electrode mixture layer 152 (including a positive electrode active material 153) formed on the surface of the positive electrode current collector 151. The negative electrode 156 has a negative electrode current collector 158 (copper foil) and a negative electrode mixture layer 159 (including a negative electrode active material 154) formed on the surface of the negative electrode current collector 158.

  In the electrode body 150 of Example 1, the direction (radial direction) orthogonal to the winding direction (circumferential direction) of the positive electrode 155, the negative electrode 156, and the separator 157 is the stacking direction. Therefore, in Example 1, as shown in FIG. 5, the direction orthogonal to the first side surface 111 and the second side surface 112 (the left-right direction in FIG. 5) is the stacking direction of the positive electrode 155, the negative electrode 156, and the separator 157. Match.

  The electrode body 150 is located at one end (right end in FIG. 3) in the axial direction (left and right in FIG. 3), and only the positive current collecting member 151 of the positive electrode 155 overlaps in a spiral shape. 150b, a negative electrode current collecting terminal portion 150c located at the other end portion (left end portion in FIG. 3), in which only the negative electrode current collecting member 158 of the negative electrode 156 is spirally overlapped, a positive electrode current collecting terminal portion 150b, and a negative electrode current collecting terminal The electrode mixture arrangement portion 150d including the positive electrode mixture layer 152 and the negative electrode mixture layer 159 is located between the electrode 150c and the portion 150c. The positive electrode current collecting terminal portion 150 b is electrically connected to the positive electrode external terminal 120 through the positive electrode connecting member 122. The negative electrode current collecting terminal portion 150 c is electrically connected to the negative electrode external terminal 130 through the negative electrode connecting member 132.

  Here, as shown in FIG. 2, a region in which the electrode body 150 is projected in a direction (vertical direction in FIG. 2) orthogonal to the first side surface 111 and the second side surface 112 is defined as an electrode projection region R1. Further, as shown in FIG. 4, a portion included in the electrode projection region R <b> 1 (a portion indicated by grid-like hatching in FIG. 4) of the first side surface 111 of the battery case 110 is an electrode region portion 111 b. . Further, as shown in parentheses in FIG. 4, a portion (indicated by hatching in FIG. 4) included in the electrode projection region R <b> 1 in the second side surface 112 of the battery case 110 is defined as an electrode region portion 112 b. To do.

In Example 1, lithium nickelate is used as the positive electrode active material 153. Further, a carbon-based material (specifically, natural graphite) is used as the negative electrode active material 154. Further, a polyethylene sheet is used as the separator 157. Further, as the non-aqueous electrolyte solution, ethylene carbonate and ethyl methyl carbonate and dimethyl carbonate, 1: 1: 1 mixed solvent of at (volume ratio), those obtained by dissolving LiPF ₆ at a concentration of 1 mol / liter Used.

  As shown in FIG. 1, the pressing means 300 includes a dimension increasing / decreasing body 70, a first member 330, and a second member 340. The size increasing / decreasing body 70 is formed of a rectangular plate-shaped piezoelectric element, and is adjacent to the first side surface 111 of the battery case 110 in the stacking direction X (left and right direction in FIG. 1) of the positive electrode 155, the negative electrode 156, and the separator 157. It is possible to increase or decrease its own dimension in the stacking direction X. The dimension increasing / decreasing body 70 can be connected to the AC power supply device 90 via the switch 92.

  The first member 330 and the second member 340 are made of a rectangular plate-like resin, and fix the battery case 110 and the dimension increasing / decreasing body 70 in the stacking direction X. Specifically, by fastening the first member 330 and the second member 340 using the cylindrical rod 51 and the nut 53, the positions of the first member 30 and the second member 40 are fixed, Between the first member 330 and the second member 340, the battery case 110 and the dimension increasing / decreasing body 70 are sandwiched and fixed in the stacking direction X.

  According to the pressing means 300, the battery case 110 can be pressed in the stacking direction X as described later. Specifically, the pressure applied to the electrode body 150 can be increased or decreased by increasing or decreasing the pressing force to the battery case 110.

  Next, the electrode body gas discharging method (electrode body gas discharging method in the secondary battery structure 200) of the first embodiment will be described. Here, the case where the secondary battery structure 200 is mounted on a mobile device as a power source of the mobile device will be described.

  When the secondary battery 100 is left in a standing state (resting state) for a certain time (for example, 72 hours) or longer, gas is likely to be generated in the battery case 110 and gas is likely to stay inside the electrode body 150. . Therefore, when the secondary battery 100 is left in a stand-by state (rest state) for a predetermined time (for example, 72 hours) or longer, the dimension increasing / decreasing body 70 is connected to the AC power supply device 90 via the switch 92. In this state, the switch 92 is turned on, and an alternating current is passed from the alternating current power supply device 90 to the dimension increasing / decreasing body 70.

  When an alternating current is passed through the dimension increasing / decreasing body 70, the dimension increasing / decreasing body 70 is repeatedly expanded and contracted, and the dimension of the dimension increasing / decreasing body 70 (piezo element) can be increased or decreased in the stacking direction X. Accordingly, the pressure applied to the electrode body 150 can be increased or decreased in the stacking direction X by increasing or decreasing the pressing force to the battery case 110. Accordingly, the gas staying inside the electrode body 150 can be discharged to the outside of the electrode body 150. Thereby, it can prevent that charging / discharging reaction is inhibited by the residence gas inside the electrode body 150, and it can prevent that battery performance falls.

  The pressure applied to the first side surface 111 and the second side surface 112 of the battery case 110 is preferably increased or decreased in the range of 0.98 MPa to 6.54 MPa. Thereby, the gas staying inside the electrode body 150 can be reliably discharged. Therefore, it is preferable to select the dimension increasing / decreasing body 70 (piezo element) so that the pressure applied to the first side surface 111 and the second side surface 112 of the battery case 110 increases or decreases in the range of 0.98 MPa to 6.54 MPa.

(Example 2)
Next, Example 2 will be described. Although the secondary battery structure 200 of Example 1 has only one secondary battery 100, the secondary battery structure 400 of Example 2 has a plurality of secondary batteries 100. Specifically, the secondary battery structure 400 constitutes an assembled battery by electrically connecting a plurality of secondary batteries 100 in series.
The secondary battery structure 400 can be used as a power source for an electric vehicle, a hybrid vehicle, or the like, for example.

  As shown in FIG. 7, the secondary battery structure 400 includes a plurality of secondary batteries 100 and pressing means 500. The plurality of secondary batteries 100 constituting the secondary battery structure 400 are arranged in a line in the stacking direction X (left and right direction in FIG. 7) of the positive electrode 155, the negative electrode 156, and the separator 157. Further, the positive external terminal 120 and the negative external terminal 130 of the adjacent secondary battery 100 are electrically connected by the connecting member 61. In FIG. 7, only four secondary batteries 100 positioned at both ends of the secondary battery structure 400 are illustrated, and a plurality of secondary batteries 100 positioned therebetween are not illustrated.

  Specifically, the connecting member 61 is made of a rectangular plate-like metal plate, and has two through holes 61b through which the positive external terminal 120 and the negative external terminal 130 can be inserted. The positive electrode external terminal 120 is inserted into one through hole 61b of the connecting member 61, and the nut 63 is screwed into the male screw of the positive electrode external terminal 120 with the negative electrode external terminal 13 inserted into the other through hole 61b. Thus, the positive electrode external terminal 120 and the connecting member 61 are fastened, and the nut 63 is screwed into the male screw of the negative electrode external terminal 130 to fasten the negative electrode external terminal 130 and the connecting member 61. In this way, the secondary batteries 100 constituting the secondary battery structure 400 are electrically connected in series.

  As shown in FIG. 7, the pressing unit 500 includes a dimension increasing / decreasing body 570, a first member 30, and a second member 40. The dimension increasing / decreasing body 570 is formed of a rectangular plate-shaped piezoelectric element, is positioned between the secondary batteries 100 adjacent to each other in the stacking direction X, and can increase or decrease its own dimension in the stacking direction X. In particular, in Example 2, the size increasing / decreasing body 570 is disposed in close contact with only the electrode region portions 111b and 112b in the battery case 110. Each of the dimension increasing / decreasing bodies 570 is connected to the AC power supply device 90 via the switch 92.

  The first member 30 and the second member 40 are made of a rectangular plate-like resin, and fix the battery case 110 and the dimension increasing / decreasing body 570 in the stacking direction X. Specifically, by fastening the first member 30 and the second member 40 using a cylindrical rod 551 and a nut 53, the positions of the first member 30 and the second member 40 are fixed, Between the first member 30 and the second member 40, the battery case 110 and the dimension increasing / decreasing body 570 are sandwiched and fixed in the stacking direction X.

  The first member 30 has a pressing main body 35 and a close pressing plate 36. The pressing main body portion 35 includes a facing portion 35b facing the first side surface 111 (excluding the electrode region portion 111b) of the secondary battery 100 located on one end side (right end side in FIG. 7). The close contact pressing plate 36 includes a close contact pressing facing portion 36 b facing the electrode region portion 111 b of the first side surface 111. The close-contact pressing opposing portion 36b protrudes by 0.2 mm toward the battery case 110 side (left side in FIG. 7) compared to the opposing portion 35b.

  The second member 40 includes a pressing main body 45 and a close pressing plate 46. The pressing main body 45 includes a facing portion 45b that faces the first side surface 111 (excluding the electrode region portion 111b) of the secondary battery 100 located on the other end side (left end side in FIG. 7). The contact pressing plate 46 includes a contact pressing facing portion 46 b that faces the electrode region portion 111 b of the first side surface 111. The close-contact pressing facing portion 46b protrudes by 0.2 mm toward the battery case 110 side (right side in FIG. 7) compared to the facing portion 45b.

Therefore, the battery case 110 and the dimension increasing / decreasing body 570 are disposed between the first member 30 and the second member 40, and the first member 30 and the second member 40 are fastened using the rod 551 and the nut 53. The electrode area portions 111b and 112b of the respective secondary batteries 100 can be surely pressed by the contact pressing opposing portions 36b and 46b of the contact pressing plates 36 and 46 and the dimension increasing / decreasing body 570.
According to the pressing means 500, as will be described later, the pressure applied to the battery case 110 can be increased or decreased to increase or decrease the pressure applied to the electrode body 150.

Next, an electrode body gas discharging method (electrode body gas discharging method in the secondary battery structure 400) of the second embodiment will be described. Here, a case where the secondary battery structure 400 is mounted on a hybrid vehicle as a power source of the hybrid vehicle, for example, will be described.
When the secondary battery 100 is left in a stand-by state (resting state) for a certain time (for example, 72 hours) or longer, the switch 92 is turned on, and the size increasing / decreasing body 570 is connected to the AC power supply device 90. Apply alternating current.

  When an alternating current is passed through the dimension increasing / decreasing body 570, the dimension increasing / decreasing body 570 is repeatedly expanded and contracted, and the dimension of the dimension increasing / decreasing body 570 (piezo element) can be increased or decreased in the stacking direction X. As a result, the pressure applied to each battery case 110 can be increased or decreased to increase or decrease the pressure applied to the electrode body 150 in the stacking direction X. Therefore, for each secondary battery 100, the gas staying inside the electrode body 150 can be discharged to the outside of the electrode body 150. Thereby, it can prevent that charging / discharging reaction is inhibited by the residence gas inside the electrode body 150, and it can prevent that battery performance falls.

(Example 3)
Next, Example 3 will be described. In Examples 1 and 2, the gas staying inside the electrode body 150 was discharged to the outside of the electrode body 150 using the pressing means 300 and 500. On the other hand, in the present Example 3, the secondary battery 100 which comprises the assembled battery 600 (refer FIG. 8) is charged / discharged, The pressure applied to the electrode body 150 is increased / decreased about the lamination direction X, and an electrode body The gas existing inside 150 is discharged to the outside of electrode body 150.
The assembled battery 600 can be used as a power source for an electric vehicle or a hybrid vehicle, for example.

  As shown in FIG. 8, the assembled battery 600 includes a plurality of secondary batteries 100, an interposition member 50 positioned between the secondary batteries 100 and in close contact with the electrode region portions 111 b and 112 b, a plurality of secondary batteries 100, and The first member 30 and the second member 40 that are fixed with the interposition member 50 interposed therebetween are provided. The plurality of secondary batteries 100 are arranged in a line (in the left-right direction in FIG. 8). Further, the positive external terminal 120 and the negative external terminal 130 of the adjacent secondary battery 100 are electrically connected by the connecting member 61.

  8 and 9, only four secondary batteries 100 located at both ends of the assembled battery 600 are illustrated, and a plurality of secondary batteries 100 located therebetween are not shown. Further, the assembled battery 600 is different from the secondary battery structure 400 (see FIG. 7) of the second embodiment in that an interposition member 50 is used instead of the size increasing / decreasing body 570.

  As shown in FIG. 9, this assembled battery 600 is connected to a known charging / discharging device 80 via a switch 82. Specifically, the first terminal 81 of the charging / discharging device 80 is connected to the positive external terminal 120 of the secondary battery 100 located at the rightmost end of the assembled battery 600, and the second terminal 82 is located at the leftmost end of the assembled battery 600. The negative battery external terminal 130 of the secondary battery 100 is connected.

Next, an electrode body gas discharging method (electrode body gas discharging method of the secondary battery 100 constituting the assembled battery 600) of the third embodiment will be described. Here, the case where the assembled battery 600 is mounted on a hybrid vehicle as a power source of the hybrid vehicle, for example, will be described.
For example, when the secondary battery 100 is left in an idle state (resting state) for a predetermined time (for example, 72 hours) or longer, the switch 82 is turned on to charge / discharge each secondary battery 100 constituting the assembled battery 600. I do.

For example, first, constant current discharge is performed at a current value of 1 C until the battery voltage (inter-terminal voltage) reaches 3.0V. Next, constant current charging is performed until the battery voltage (terminal voltage) reaches 4.1 V at a current value of 1C. This charging / discharging is defined as one cycle, and this charging / discharging cycle is performed for a predetermined number of cycles (for example, 10 cycles).
In addition, since the secondary battery 100 which comprises the assembled battery 600 is electrically connected in series, all the secondary batteries 100 which comprise the assembled battery 600 are equal by charging / discharging as mentioned above. It can be charged and discharged.

  When the secondary battery 100 is charged, the electrode body 150 expands, and then when the secondary battery 100 is discharged, the electrode body 150 contracts. When the electrode body 150 expands due to charging, the electrode body 150 presses the inner surfaces 113 and 114 of the battery case 110. The pressure on the electrode body 150 can be increased by the reaction force from the battery case 110 at this time. Thereafter, when the electrode body 150 contracts due to discharge, the force with which the electrode body 150 presses the inner surfaces 113 and 114 of the battery case 110 is weakened, so that the pressure applied to the electrode body 150 is reduced. Therefore, by charging / discharging the secondary battery 100, the pressure applied to the electrode body 150 can be easily increased or decreased in the stacking direction X (the left-right direction in FIG. 9) of the positive electrode 155, the negative electrode 156, and the separator 157. it can.

  Moreover, in the third embodiment, each secondary battery 100 is charged in a state where the battery case 110 and the interposition member 50 are sandwiched and fixed by the first member 30 and the second member 40 in the stacking direction X. For this reason, the expansion of the battery case 100 pressed by the electrode body 150 can be prevented. As a result, the force applied to the battery case 110 by the electrode body 150 can be directly applied to the electrode body 150 as a reaction force without escaping to the outside, so that the pressure applied to the electrode body 150 can be increased.

  Therefore, each secondary battery 100 is charged / discharged in a state where the battery case 110 and the interposition member 50 are sandwiched and fixed by the first member 30 and the second member 40 in the stacking direction X, and thus added to the electrode body 150. The increase / decrease in pressure can be increased. Thereby, the gas staying inside the electrode body 150 can be discharged to the outside of the electrode body 150 more reliably.

Example 4
In Examples 1 to 3, an electrode body gas discharging method for a secondary battery mounted as a power source for a portable device or a hybrid vehicle has been shown. On the other hand, Example 4 shows an electrode body gas discharging method in the manufacturing process of the secondary battery. Specifically, a method for manufacturing a secondary battery capable of appropriately discharging the gas staying inside the electrode body with the initial charge to the outside of the electrode body will be described.

Below, the manufacturing method of the secondary battery 100 is demonstrated.
First, a secondary battery is assembled. Specifically, first, lithium nickelate (positive electrode active material 153), acetylene black, polytetrafluoroethylene, and carboxymethylcellulose are mixed at a ratio of 88: 10: 1: 1 (weight ratio) and dispersed therein. A solvent was mixed to prepare a positive electrode slurry. Next, this positive electrode slurry was applied to the surface of an aluminum foil 151 having a thickness of 15 μm, dried, and then pressed. Thereby, the positive electrode 155 in which the positive electrode mixture 152 was coated on the surface of the aluminum foil 151 was obtained (see FIG. 6).

  Natural graphite (negative electrode active material 154), styrene-butadiene rubber, and carboxymethylcellulose were mixed in water at a ratio of 98: 1: 1 (weight ratio) to prepare a negative electrode slurry. Next, this negative electrode slurry was applied to the surface of a copper foil 158 having a thickness of 10 μm, dried, and then pressed. Thereby, the negative electrode 156 by which the negative electrode compound material 159 was coated on the surface of the copper foil 158 was obtained (refer FIG. 6).

  Next, a positive electrode 155, a negative electrode 156, and a separator 157 were stacked and wound to form an electrode body 150 having an oval cross section (see FIG. 5). However, when laminating the positive electrode 155, the negative electrode 156, and the separator 157, an uncoated portion of the positive electrode 155 that is not coated with the positive electrode mixture 152 protrudes from one end portion of the electrode body 150. The positive electrode 155 is disposed. Furthermore, the negative electrode 156 is disposed so that an uncoated portion of the negative electrode 156 that is not coated with the negative electrode mixture 159 protrudes from the side opposite to the uncoated portion of the positive electrode 155. Thereby, the electrode body 150 having the positive electrode current collecting terminal portion 150b in which only the positive electrode current collecting member 151 of the positive electrode 155 overlaps in a spiral shape and the negative electrode current collection terminal portion 150c in which only the negative electrode current collecting member 158 of the negative electrode 156 overlaps in a spiral shape. (See FIG. 3) is formed. As the separator 157, a polyethylene sheet having a thickness of 25 μm is used.

Next, the positive electrode current collecting terminal portion 150 b of the electrode body 150 and the positive electrode external terminal 120 are connected through the positive electrode current collecting member 122. Further, the negative electrode current collecting terminal portion 150 c of the electrode body 150 and the negative electrode external terminal 130 are connected through the negative electrode current collecting member 132. Then, this was accommodated in the battery case main body 117, the battery case main body 117 and the battery case cover 118 were welded, and the battery case 110 was sealed. Next, an electrolyte solution is injected through a solution injection port (not shown) provided in the battery case lid 118, and then the solution injection port is sealed. In addition, as a non-aqueous electrolyte, a solution obtained by dissolving LiPF ₆ at a concentration of 1 mol / liter in a solvent in which ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate are mixed at 1: 1: 1 (volume ratio). Used.

  Next, the secondary battery 100 was initially charged. Specifically, the secondary battery 100 was charged to a SOC of 50% with a current value of 0.1 C using a known power supply device. Furthermore, it charged to SOC100% with the electric current value of 0.5C. In this way, the secondary battery 100 was fully charged. When this initial charging is performed, a decomposition reaction of the non-aqueous electrolyte occurs, and gas is generated by this decomposition reaction. A part of the generated gas may stay inside the electrode body 150 (between the positive electrode 155 and the separator 157 or between the negative electrode 156 and the separator 157).

  Next, as shown in FIG. 10, the battery case 110 is sandwiched between the positive electrode 155, the negative electrode 156, and the separator 157 in the stacking direction X (left and right direction in FIG. 10) by the first member 30 and the second member 40. Fixed. Specifically, the first member 30 disposed on the first side surface 111 side of the secondary battery 100 and the second member 40 disposed on the second side surface 112 side are used by using a cylindrical rod 51 and a nut 53. And concluded.

In this state, as shown in FIG. 11, the secondary battery 100 is charged / discharged using a known charging / discharging device 80. Specifically, the first terminal 81 of the charging / discharging device 80 is connected to the positive external terminal 120 of the secondary battery 100, and the second terminal 82 is connected to the negative external terminal 130. For example, the same charging as in Example 3 is performed. The discharge cycle is performed for a predetermined number of cycles (for example, 10 cycles). Also in the fourth embodiment, similarly to the third embodiment, by charging and discharging the secondary battery 100 in a state where the battery case 110 is sandwiched and fixed by the first member 30 and the second member 40 in the stacking direction X, The increase / decrease in the pressure applied to the electrode body 150 can be increased. Thereby, the gas staying inside the electrode body 150 with the initial charging can be reliably discharged to the outside of the electrode body 150.
Thereafter, the secondary battery 100 is completed through a predetermined inspection process and the like.

(Example 5)
In Examples 1 and 2, a piezo element was used as a dimension increasing / decreasing body of the pressing means. Specifically, by passing an alternating current through the piezo element, the piezo element was repeatedly expanded and contracted, and the dimensions of the piezo element were increased or decreased in the stacking direction X. On the other hand, in the fifth embodiment, as a size increasing / decreasing body, a hydraulic bag (see FIG. 12) that expands and contracts itself by increasing or decreasing the hydraulic pressure is used.

  Specifically, the secondary battery structure 700 of the fifth embodiment includes a secondary battery 100 and a pressing unit 800 as shown in FIG. The pressing unit 800 includes a dimension increasing / decreasing body 870, a first member 330, and a second member 340. The size increasing / decreasing body 870 is a rectangular bag-shaped rubber hydraulic bag, and is arranged in the stacking direction X (left-right direction in FIG. 12) of the positive electrode 155, the negative electrode 156, and the separator 157 with respect to the first side surface 111 of the battery case 110. Adjacent to each other, the dimension can be increased or decreased in the stacking direction X.

  The dimension increasing / decreasing body 870 is connected to an electromagnetic valve 96 that switches between supply and discharge of hydraulic oil through a hydraulic oil pipe. The oil supply port of the electromagnetic valve 96 is connected to a hydraulic oil tank 95 in which the hydraulic oil is stored through a hydraulic oil pipe 97 through a hydraulic oil pipe. Further, the oil outlet of the solenoid valve 96 is connected to the hydraulic oil tank 95 through the hydraulic oil pipe.

  When the hydraulic valve 96 is switched to the supply side and hydraulic oil is supplied from the hydraulic oil tank 95 to the size increasing / decreasing body 870 by driving the hydraulic pump 97, the size increasing / decreasing body 870 expands, The dimension in the stacking direction X increases. On the other hand, when the solenoid valve 96 is switched to the discharge side and the hydraulic oil is discharged from the dimension increasing / decreasing body 870, the dimension increasing / decreasing body 870 contracts and the dimension of the dimension increasing / decreasing body 870 in the stacking direction X decreases. In this way, by supplying and discharging the hydraulic oil to and from the dimension increasing / decreasing body 870, the dimension of the dimension increasing / decreasing body 870 (hydraulic bag) can be increased or decreased in the stacking direction X.

  Accordingly, the pressure applied to the electrode body 150 can be increased or decreased in the stacking direction X by increasing or decreasing the pressing force to the battery case 110. Accordingly, the gas staying inside the electrode body 150 can be discharged to the outside of the electrode body 150. Thereby, it can prevent that charging / discharging reaction is inhibited by the residence gas inside the electrode body 150, and it can prevent that battery performance falls.

(Example 6)
In Examples 1 and 2, the pressing means is composed of the first member, the second member, and the dimension increasing / decreasing body. On the other hand, in the sixth embodiment, the pressing means is constituted by the first member, the second member, and the reciprocating means (hydraulic cylinder 911).

  Specifically, the secondary battery structure 900 of the sixth embodiment includes a secondary battery 100 and a pressing unit 910 as shown in FIG. The pressing unit 910 includes a first member 30 and a second member 40 that fix the secondary battery 100 in the stacking direction X, and a hydraulic cylinder 911. The hydraulic cylinder 911 has a cylinder body 911c and a rod portion 911b that reciprocates in the stacking direction X (left and right in FIG. 13) by supplying and discharging hydraulic oil into and from the cylinder body 911c. The tip 911 d of the rod portion 911 b is fixed to the outer surface of the first member 30.

  The 1st entrance / exit 911f located in the rear-end side of the cylinder main-body part 911c is connected with the solenoid valve 912 which switches supply and discharge | emission of hydraulic fluid through the hydraulic fluid pipe 915b. The 2nd entrance / exit 911g located in the front end side of the cylinder main-body part 911c is connected with the solenoid valve 912 through the hydraulic oil pipe 915c. The oil supply port of the electromagnetic valve 912 is connected to the hydraulic oil tank 914 in which the hydraulic oil is stored via the hydraulic pump 913 through the hydraulic oil pipes 915d and 915e. The oil outlet of the electromagnetic valve 912 is connected to the hydraulic oil tank 914 through the hydraulic oil pipe 915f.

  When hydraulic oil is supplied from the hydraulic oil tank 914 to the cylinder main body 911c through the first inlet / outlet 911f of the cylinder main body 911c by driving the hydraulic pump 913, the rod portion 911b is moved in the stacking direction X. Move (extend) in a direction approaching the battery case 110 (leftward in FIG. 13). Thereby, the first member 30 to which the tip 911d of the rod portion 911b is fixed is moved in the stacking direction X in the direction approaching the battery case 110 (left direction in FIG. 13), and the pressing force to the battery case 110 Can be increased.

  The position of the second member 40 is fixed, and even if the first member 30 moves in the stacking direction X, the second member 40 does not move. Further, the first member 30 is movable in the stacking direction X along the rod 51.

  Conversely, when hydraulic fluid is supplied into the cylinder main body 911c through the second inlet / outlet 911f of the cylinder main body 911c, the rod 911b moves in the stacking direction X away from the battery case 110 (rightward in FIG. 13). (Shorten. Accordingly, the first member 30 to which the tip 911d of the rod portion 911b is fixed is moved in the stacking direction X in the direction away from the battery case (right direction in FIG. 13), so that the pressing force to the battery case 110 is reduced. Can be reduced.

  Therefore, the rod portion 911b of the hydraulic cylinder 911 (reciprocating means) is reciprocated (expanded) in the stacking direction X, thereby increasing or decreasing the pressing force to the battery case 110 (specifically, the electrode region portions 111b and 112b). Can be made. Thereby, since the pressure applied to the electrode body 150 can be increased or decreased in the stacking direction X, the gas staying inside the electrode body 150 can be discharged to the outside of the electrode body 150. Therefore, it is possible to prevent the charge / discharge reaction from being inhibited by the staying gas inside the electrode body 150 and to prevent the battery performance from deteriorating.

  In addition, it is preferable to increase / decrease the pressure added to the electrode area | region parts 111b and 112b of the battery case 110 in the range of 0.98 MPa-6.54 MPa. Thereby, the gas staying inside the electrode body 150 can be reliably discharged. Therefore, the hydraulic oil 911 (reciprocating means) is supplied with hydraulic oil so that the pressure applied to the first side surface 111 and the second side surface 112 of the battery case 110 increases or decreases in the range of 0.98 MPa to 6.54 MPa. It is preferred to control the discharge.

(Example 7)
In the sixth embodiment, the reciprocating means is constituted by the hydraulic cylinder 911. On the other hand, in the seventh embodiment, the reciprocating means is constituted by a piston connected to a motor through a connecting rod and a crankshaft.

  Specifically, the secondary battery structure 920 of Example 7 includes a secondary battery 100 and a pressing unit 930 as shown in FIG. The pressing unit 930 includes a first member 30 and a second member 40 that fix the secondary battery 100 in the stacking direction X, and a piston 931 that is fixed to the first member 30. The piston 931 is connected to a connecting rod 932 that extends in the stacking direction X (left-right direction in FIG. 14). The connecting rod 932 is connected to a crankshaft 933 that extends in a direction orthogonal to the stacking direction X (the vertical direction in FIG. 14). The crankshaft 933 is connected to a motor 934, and rotates with the shaft 933b as a rotation axis by driving the motor 934.

  Therefore, when the motor 934 is driven, the crankshaft 933 rotates, and the connecting rod 932 connected to the crankshaft 933 reciprocates in the stacking direction X. As a result, the piston 931 connected to the connecting rod 932 reciprocates in the stacking direction X. Accordingly, the first member 30 to which the piston 931 is fixed reciprocates in the stacking direction X. That is, the first member 30 moves in the stacking direction X in the direction approaching the battery case (leftward in FIG. 14), and then moves in the stacking direction X in the direction away from the battery case (rightward in FIG. 14). To do.

  Therefore, by driving the motor 934, the first member 30 together with the piston 931 can be reciprocated in the stacking direction X to increase or decrease the pressing force to the battery case 110 (specifically, the electrode region portions 111b and 112b). . Thereby, since the pressure applied to the electrode body 150 can be increased or decreased in the stacking direction X, the gas staying inside the electrode body 150 can be discharged to the outside of the electrode body 150. Therefore, it is possible to prevent the charge / discharge reaction from being inhibited by the staying gas inside the electrode body 150 and to prevent the battery performance from deteriorating.

  As in the sixth embodiment, the position of the second member 40 is fixed, and even if the first member 30 moves in the stacking direction X, the second member 40 does not move. Further, the first member 30 is movable in the stacking direction X along the rod 51.

  In the above, the present invention has been described with reference to the first to fifth embodiments. However, the present invention is not limited to the above-described embodiments, and it can be applied as appropriate without departing from the scope of the present invention. Nor.

  For example, in the fifth embodiment, a method of discharging the gas staying inside the electrode body 150 to one secondary battery 100 using the pressing means 800 having the dimension increasing / decreasing body 870 (hydraulic bag) is shown. It was. However, for the plurality of secondary batteries 100, the gas staying inside the electrode body 150 may be discharged at the same time by using a pressing means having a dimension increasing / decreasing body 870 (hydraulic bag).

  Specifically, for example, in the secondary battery structure 400 of Example 2, a size increasing / decreasing body 870 (hydraulic bag) may be used instead of the size increasing / decreasing body 570 (piezo element). Each size increasing / decreasing body 870 (hydraulic bag) disposed between the secondary batteries 100 is connected to the oil tank 95 via the electromagnetic valve 96, and oil is supplied to each size increasing / decreasing body 870 by switching the electromagnetic valve 96. , The dimension of the dimension increasing / decreasing body 870 (hydraulic bag) can be increased / decreased in the stacking direction X. Thereby, the pressure applied to each battery case 110 can be increased or decreased to increase or decrease the pressure applied to each electrode body 150 in the stacking direction X.

  Further, in Examples 6 and 7, the method of discharging the gas staying inside the electrode body 150 to one secondary battery 100 using the pressing means 910 and 930 was shown. However, for the plurality of secondary batteries 100, the gas staying inside the electrode body 150 may be discharged using the pressing means 910 and 930 at the same time.

  Specifically, for example, as in the sixth and seventh embodiments, the battery pack 600 of the third embodiment may be provided with pressing means 910 and 930 to form a secondary battery structure. In the same manner as in Example 6, by reciprocating the rod portion 911b of the hydraulic cylinder 911 in the stacking direction X, the pressing force on the battery case 110 is increased or decreased for each secondary battery 100 constituting the assembled battery 600. be able to. Alternatively, in the same manner as in Example 7, by reciprocating the piston 931 in the stacking direction X, the pressing force to the battery case 110 can be increased or decreased for each secondary battery 100 constituting the assembled battery 600. . Thereby, the pressure applied to each electrode body 150 can be increased or decreased in the stacking direction X.

1 is a diagram showing a secondary battery structure 200 of Example 1. FIG. 3 is a top view of the secondary battery 100. FIG. FIG. 3 is a diagram showing an internal structure of the secondary battery 100, and corresponds to a cross-sectional view taken along the line CC in FIG. 1 is a front view of a secondary battery 100. FIG. FIG. 3 is a diagram showing an internal structure of the secondary battery 100 and corresponds to a cross-sectional view taken along the line FF in FIG. 2. FIG. 6 is an enlarged cross-sectional view of the electrode body 150 and corresponds to an enlarged view of a part B in FIG. 5. 6 is a diagram showing a secondary battery structure 400 of Example 2. FIG. 4 is a longitudinal sectional view of an assembled battery 600. FIG. It is explanatory drawing explaining the electrode body gas discharge | emission method of Example 3. FIG. It is explanatory drawing explaining the electrode body gas discharge | emission method of Example 4. FIG. It is explanatory drawing explaining the electrode body gas discharge | emission method of Example 4. FIG. 6 is a diagram showing a secondary battery structure 700 of Example 5. FIG. 6 is a view showing a secondary battery structure 900 of Example 6. FIG. FIG. 10 is a view showing a secondary battery structure 920 of Example 7.

Explanation of symbols

30, 330 First member 40, 340 Second member 70, 570, 870 Size increasing / decreasing body 100 Secondary battery 110 Battery case 111 First side surface 111b, 112b Electrode region portion 112 Second side surface 120 Positive electrode external terminal 130 Negative electrode external terminal 150 Electrode body 155 Positive electrode 156 Negative electrode 157 Separator 200, 400, 700, 900, 920 Secondary battery structure 300, 500, 800, 910, 930 Press means 911 Hydraulic cylinder (reciprocating means)
931 piston (reciprocating means)
R1 Electrode projection area X Stack direction of positive electrode, negative electrode, and separator

Claims (10)

A secondary battery having an electrode body formed by laminating a positive electrode, a negative electrode, and a separator is present in the electrode body by increasing or decreasing the pressure applied to the electrode body in the stacking direction of the positive electrode, negative electrode, and separator. An electrode body gas discharging method for a secondary battery, wherein the gas is discharged outside the electrode body. The electrode body gas discharging method of the secondary battery according to claim 1,
The secondary battery includes a battery case that houses the electrode body,
A secondary battery that uses a pressing means that presses the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, and increases or decreases the pressure applied to the battery case by the pressing means. Electrode body gas discharge method. An electrode body gas discharging method for a secondary battery according to claim 2,
The pressing means is
A size increasing / decreasing body that is adjacent to and in contact with the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, and that can increase or decrease its own dimension in the stacking direction;
An electrode body gas discharge method for a secondary battery, comprising: a first member and a second member that sandwich and fix the battery case and the dimension increasing / decreasing body in the stacking direction. It is the electrode body gas discharge | emission method of the secondary battery of Claim 3, Comprising:
The dimension increasing / decreasing body is a piezo element,
An electrode body gas discharge method for a secondary battery, wherein an alternating current is passed through the piezoelectric element to increase or decrease the dimensions of the piezoelectric element in the stacking direction of the positive electrode, the negative electrode, and the separator. An electrode body gas discharging method for a secondary battery according to claim 2,
The pressing means is
A first member and a second member for fixing the battery case sandwiched in the stacking direction;
Reciprocating means for reciprocating the first member in the stacking direction, and reciprocating means for reciprocating the first member to increase or decrease the pressing force to the battery case. Body gas discharge method. The electrode body gas discharging method of the secondary battery according to claim 1,
An electrode body gas discharge method for a secondary battery, wherein the secondary battery is charged and discharged to increase or decrease the pressure applied to the electrode body. The electrode body gas discharging method of the secondary battery according to claim 6,
An electrode body gas discharge of a secondary battery that charges and discharges the secondary battery in a state where the battery case is sandwiched and fixed by the first member and the second member in the stacking direction of the positive electrode, the negative electrode, and the separator. Method. An electrode body formed by laminating a positive electrode, a negative electrode, and a separator;
A battery case containing the electrode body, and a secondary battery,
A pressing unit that presses the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, the pressing unit increasing or decreasing the pressure applied to the battery case by the pressing unit. And a secondary battery structure. The secondary battery structure according to claim 8,
The pressing means is
A size increasing / decreasing body that is adjacent to and in contact with the battery case in the stacking direction of the positive electrode, the negative electrode, and the separator, and that can increase or decrease its own dimension in the stacking direction;
A secondary battery structure comprising: a first member and a second member that fix the battery case and the dimension increasing / decreasing body in the stacking direction. The secondary battery structure according to claim 8,
The pressing means is
A first member and a second member for fixing the battery case sandwiched in the stacking direction;
Reciprocating means for reciprocating the first member in the stacking direction, and reciprocating means for reciprocating the first member to increase / decrease the pressing force to the battery case. .

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