JP2008192432A - Secondary battery and secondary battery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems wherein, in a conventional secondary battery, the swelling of one secondary battery is difficult to individually detect, and in addition, slight swelling of the secondary battery is difficult to detect, because the swelling of the secondary battery is detected from the stacking height of a plurality of secondary batteries. <P>SOLUTION: A battery element 11 having an electrode terminal 12, a packaging member 13 from which a part of the electrode terminal 12 is exposed and in which the battery element 11 is sealed, and a conductor 27 fixed to the outer surface of the packaging member 13 in at least two portions to break when the packaging member 13 is swelled are installed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a secondary battery in which a part of an electrode terminal is exposed and a battery element is sealed with a packaging member, and a secondary battery device provided with the secondary battery, and particularly detects an abnormality from the expansion of the packaging member. The present invention relates to a secondary battery and a secondary battery device.

  With the advent of portable electronic devices in recent years, electronic devices have been reduced in size and weight, and the demand for such devices has increased. Along with this, there is an increasing demand for thinning and folding of secondary batteries as portable power sources for these electronic devices, especially lithium ion secondary batteries. A non-aqueous electrolyte secondary battery formed by laminating a positive electrode sheet and a negative electrode sheet is known as a thin and foldable secondary battery.

  A lithium ion secondary battery is a battery that uses a lithium-containing compound as a positive electrode active material, a carbon-based material as a negative electrode active material, and a non-aqueous electrolyte solution in which an electrolyte salt is dissolved in a non-aqueous solvent. This lithium ion secondary battery is a typical secondary battery having a high energy density.

  However, when a thin lithium ion secondary battery is produced using a conventional non-aqueous electrolyte, the liquid inside leaks and there is a risk of affecting surrounding electronic components. Therefore, a solid electrolyte obtained by solidifying the electrolytic solution has been proposed. In particular, a gel-like solid electrolyte in which a matrix polymer is impregnated with a nonaqueous electrolytic solution can be expected to have a high level of ionic conductivity equivalent to the electrolytic solution because the electrolytic solution phase serves as a main path for ionic conduction. Therefore, development of a lithium ion secondary battery using a solid electrolyte is being promoted.

  However, in the secondary battery using the current solid electrolyte, there is a possibility that the solvent is decomposed and gas is generated due to overdischarge, and the packaging member that houses the battery element is swollen. As a result, in the secondary battery device storing the secondary battery, there is a problem that the case opens due to the swelling of the secondary battery.

  Moreover, as a conventional secondary battery of this type, for example, there is a battery described in Patent Document 1. Patent Document 1 describes a battery pack that is formed by stacking a plurality of flat rectangular secondary batteries, and particularly, a battery pack that takes measures when a bulge occurs in a secondary battery. Yes. The stacked battery pack described in Patent Document 1 is “a plurality of secondary batteries formed in a flat rectangular shape are stacked on their long sides and electrically connected in series and / or in parallel and accommodated in a pack case. In the stacked battery pack, the plurality of secondary batteries are arranged and stacked in a state where the thermal element is electrically connected in series with the positive electrode terminal or the negative electrode terminal and in close contact with the short side surface and thermally coupled. A plurality of secondary batteries are bundled to a predetermined stacking height by a plurality of lead plates electrically connected in series and / or in parallel on the short side surface, and the secondary battery is swollen and the stacking height exceeds a predetermined value. A connection breaking structure is provided in which the electrical connection state by the lead plate is broken when increased.

According to the multilayer battery pack having such a configuration, “when the thermal coupling state of the thermal element to the secondary battery is broken, the function of protecting the secondary battery from a short circuit or a high temperature state does not work normally. The secondary battery increases in bulge due to the progress of the high temperature state, but when the bulge progresses to the limit state, the charge / discharge circuit is interrupted by the connection break structure provided in the lead plate, so the secondary battery is An effect such as “a worst state such as a rupture is prevented” (paragraph [0033] of the specification) is expected.
JP 2004-273221 A

  However, the stacked battery pack described in Patent Document 1 stacks a plurality of secondary batteries, attaches a lead plate to the short side surface thereof, and when the stack height increases to a predetermined value or more, A connection breaking structure for breaking the connection state is provided. As a result, since the secondary battery bulge was detected from the change in the stack height of multiple secondary batteries, it was difficult to detect the secondary battery bulge individually. There was a problem that it was difficult to detect.

  The problem to be solved is that in the conventional secondary battery, since the swelling of the secondary battery is detected from the change in the stacking height of the plurality of secondary batteries, it is possible to individually detect the swelling of the secondary battery. In addition, it is difficult to detect a minute bulge of the secondary battery.

  The secondary battery of the present invention includes a battery element having an electrode terminal, a packaging member that exposes a part of the electrode terminal to seal and store the battery element, and the packaging so that the packaging member breaks when the packaging member expands. The main feature is that a conductor fixed at two or more places on the outer surface of the member is provided.

  The secondary battery device of the present invention includes a battery element having an electrode terminal, a packaging member that exposes a part of the electrode terminal and seals and stores the battery element, and that the packaging member breaks when the packaging member expands. A conductor that is fixed to the outer surface of the packaging member at two or more locations, and an expansion detection circuit unit that detects a breakage of the conductor from an energized state of the conductor and outputs a detection signal thereof, To do.

  According to the secondary battery and the secondary battery device of the present invention, the abnormality of the secondary battery and the secondary battery device can be detected by breaking the conductor due to the swelling of the packaging member.

  By fixing the conductor that is broken (cut) when the swelling of the packaging member exceeds a predetermined value to the packaging member in at least two places, the swelling of the packaging member of the secondary battery is reliably detected, and the abnormality of the secondary battery A secondary battery and a secondary battery device capable of detecting the above are realized with a simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 15 show examples of embodiments of the present invention. 1 is a front view showing a first embodiment of the secondary battery of the present invention, FIG. 2 is a side view, FIG. 3 is a perspective view, and FIG. 4 is a first embodiment of the battery element of the present invention. FIG. 5 is a sectional view taken along the line TT in FIG. 3, FIG. 6 shows a state in which the packaging member has expanded within a predetermined range, FIG. 6A is a front view, FIG. 6B is a side view, and FIG. 6C is a plan view. 7 shows a state where the packaging member has expanded beyond a predetermined range, FIG. 7A is a front view, FIG. 7B is a side view, and FIG. 7C is a plan view. FIG. 8 is a front view showing a first example of the secondary battery device of the present invention, FIG. 9 is an explanatory diagram schematically showing the first example of the expansion detection circuit unit, and FIG. 10 is a secondary battery device. It is a flowchart which shows the 1st Example of this abnormality detection process.

  FIG. 11 is a cross-sectional explanatory view showing a second embodiment of the secondary battery of the present invention, FIG. 12 is a perspective view showing a third embodiment of the secondary battery of the present invention, and FIG. FIG. 14 is an explanatory view schematically showing a fifth embodiment of the secondary battery of the present invention, and FIG. 15 is an explanatory view schematically showing the fourth embodiment of the secondary battery of FIG. It is explanatory drawing which shows typically the 6th Example of a secondary battery.

  First, with reference to FIGS. 1-7, the 1st Example of the secondary battery of this invention is described. The secondary battery 10 shown in the present embodiment is, for example, a lithium ion battery. As shown in FIGS. 1 and 2, the secondary battery 10 includes a packaging member 13 formed of a laminate film, and a battery element 11 having a thin substantially rectangular parallelepiped shape that is sealed and accommodated inside the packaging member 13. A conductor 27 fixed so as to be wound around the packaging member 13 is provided. The shape of the secondary battery 10 in this embodiment is a thin, substantially rectangular parallelepiped, but is not limited to this, for example, a cylinder, a prism, a flat shape obtained by thinly crushing a cylinder or a prism, etc. Other shapes may be used.

  The packaging member 13 is formed of a laminate film. This laminate film is configured as a laminate including a conductive film and two non-conductive films sandwiching the conductive film. The conductive film and the two non-conductive films are bonded to each other through an adhesive layer. Further, the adhesive layer may be omitted as necessary.

  In addition to improving the strength of the laminate film, the conductive film has a role of preventing moisture, air and light from entering and protecting the contents. As the material of the conductive film, aluminum (Al) is preferably used because of its lightness, extensibility, cost, ease of processing, and the like.

  When the secondary battery 10 is formed, the non-conductive film is composed of an exterior film located outside and a sealant film located inside. The exterior film is required to have a beautiful appearance, toughness, flexibility, and the like. As the material of the exterior film, polyolefin resin, polyamide resin, polyimide resin, polyester, or the like is used. Specifically, nylon (Ny), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polybutylene naphthalate (PBN) are used. Moreover, you may select and use these several types for the material of an exterior film | membrane.

  The sealant film is a part that melts and fuses with heat or ultrasonic waves. The material of the sealant film includes polyethylene (PE), non-axially oriented polypropylene (CPP), polyethylene terephthalate (PET), nylon (Ny), low density polyethylene (LDPE), high density polyethylene (HDPE), straight A linear low density polyethylene (LLDPE) or the like is used. Moreover, you may select and use multiple types for the material of a sealant film | membrane.

  As shown in FIGS. 3 and 5, the packaging member 13 includes a front portion 13 a that is substantially rectangular, an upper surface portion 13 b that is continuous so as to be substantially vertical from one side in the longitudinal direction Y of the front portion 13 a, and a front surface. The bottom portion 13c continued so as to be substantially perpendicular from the other side of the longitudinal direction Y of the portion 13a, and continued so as to be substantially perpendicular from one side of the width direction X orthogonal to the longitudinal direction Y of the front portion 13a. The left side surface portion 13d, the right side surface portion 13e continuous so as to be substantially perpendicular from the other side in the width direction X of the front surface portion 13a, the front surface portion 13a, and the bottom surface portion 13c are continuous so as to form a substantially rectangular shape. The rear surface portion 13f is provided. The front portion 13a, the upper surface portion 13b, the bottom surface portion 13c, the left side surface portion 13d, and the right side surface portion 13e constitute the bulging portion 23. The battery element 11 is accommodated in the bulging portion 23.

  Further, around the battery element 11, a superposed portion 24 in which the periphery of the packaging member 13 overlaps is formed. On one side of the width direction X across the battery element 11 of the overlapping portion 24, a first overlapping portion 24a is disposed. A second overlapping portion 24b is disposed on the other side of the width direction X across the battery element 11 of the overlapping portion 24. The first overlapping portion 24a is bent once toward the front portion 13a to form a first bent portion 26a. Similarly, the second overlapping portion 24b is bent once toward the front portion 13a to form a second bent portion 26b. Further, as shown in FIG. 3, a third overlapping portion 24 c is disposed on one side of the longitudinal direction Y across the battery element of the overlapping portion 24. The electrode terminal 12 described later is interposed between the third overlapping portions 24c.

  As shown in FIGS. 4 and 5, the battery element 11 includes a strip-shaped positive electrode 14, a separator 15 a, a strip-shaped negative electrode 16 disposed so as to face the positive electrode 14, and a separator 15 b in this order. It is wound around. A gel electrolyte (not shown) is formed on both surfaces of the positive electrode 14 and the negative electrode 16. A plate-like electrode terminal 12 is connected to each of the positive electrode 14 and the negative electrode 16. Specifically, a positive electrode terminal 12 a is connected to the positive electrode 14, and a negative electrode terminal 12 b is connected to the negative electrode 16. Moreover, in order to improve adhesiveness with the packaging member 13, the resin pieces 18a and 18b are coat | covered on each both surfaces in the one end part of the positive electrode terminal 12a and the negative electrode terminal 12b.

  The positive electrode 14 includes a positive electrode active material layer 14a containing a positive electrode active material and a positive electrode current collector 14b. The positive electrode active material layer 14a is formed on both surfaces of the positive electrode current collector 14b. Further, the positive electrode active material layer 14a is configured to contain, for example, a positive electrode active material, a conductive agent, and a binder. The positive electrode current collector 14b is made of a metal foil such as an aluminum (Al) foil, a nickel (Ni) foil, or a stainless steel (SUS) foil.

  The positive electrode terminal 12a of the positive electrode 14 is connected to one end of the positive electrode current collector 14b by spot welding or ultrasonic welding. Examples of the material of the positive electrode terminal 12a include aluminum (Al). The material of the positive electrode terminal 12a does not have to be a metal as long as it is electrochemically and chemically stable and can conduct electricity.

  The negative electrode 16 includes a negative electrode active material layer 16a containing a negative electrode active material and a negative electrode current collector 16b. The negative electrode active material layer 16a is formed on both surfaces of the negative electrode current collector 16b. Further, the negative electrode active material layer 16a is configured to contain, for example, a negative electrode active material, a conductive agent, and a binder. The negative electrode current collector 16b is made of a metal foil such as a copper (Cu) foil, a nickel (Ni) foil, or a stainless steel (SUS) foil.

  The negative electrode terminal 12b of the negative electrode 16 is connected to one end of the negative electrode current collector 16b by spot welding or ultrasonic welding. Examples of the material of the negative electrode terminal 12b include copper (Cu) and nickel (Ni). Moreover, the material of the negative electrode terminal 12b does not need to be a metal as long as it is electrochemically and chemically stable and can conduct electricity.

  The electrolyte includes an electrolytic solution and a polymer compound serving as a holding body that holds the electrolytic solution, and is in a so-called gel form. This gel electrolyte can obtain high ionic conductivity and can prevent leakage of the electrolyte in the secondary battery.

  Separator 15a, 15b is comprised by the porous film | membrane which consists of inorganic materials, such as a porous film | membrane made from polyolefin materials, such as a polypropylene (PP) or polyethylene (PE), for example, or a ceramic nonwoven fabric. The separators 15a and 15b may have a structure in which two or more kinds of porous films are laminated. In particular, the separators 15a and 15b are preferably made of a polyethylene or polypropylene porous film.

  Furthermore, if the separators 15a and 15b are too thick, the filling amount of the active material is lowered, the battery capacity is lowered, the ionic conductivity is lowered, and the current characteristics are lowered. On the other hand, if the separators 15a and 15b are too thin, the mechanical strength of the film decreases. Therefore, 5-50 micrometers is suitable for the thickness of separator 15a, 15b, and 7-30 micrometers is more preferable.

  The conductor 27 is configured as a wire. The conductor 27 is broken (cut) when the expansion of the packaging member 13 exceeds a predetermined value. And this conductor 27 is formed with the material (material which can take electricity) which can transmit electricity, such as copper, aluminum, and steel. In the present embodiment, the conductor 27 has been described as a wire. However, the present invention is not limited to this. For example, a thin sheet material such as a foil shape or a mesh shape may be used.

  As shown in FIG. 5, the conductor 27 having such a configuration is arranged along the width direction X on the outer surface of the packaging member 13 in which the battery element 11 is housed, along the front surface portion 13 a, the left side surface portion 13 d, and the back surface portion 13 f. Are wound so as to continuously pass through the approximate center in the longitudinal direction Y. And the end 27a of the terminal part of this conductor 27 is pulled out from the end by the side of the right side part 13e in the front part 13a. The other end 27b of the terminal portion of the conductor 27 is drawn outward from one end of the back surface portion 13f on the right side surface portion 13e side.

  And the conductor 27 has the fixing | fixed part B located in the both ends of the width direction X of the fixing part A and A and the back surface part 13f which locate the insulating material 28 mentioned later in the width direction X of the front part 13a in the packaging member 13. , B are bonded and fixed with an adhesive 29. Thereby, the conductor 27 is fixed to the packaging member 13. As a result, when an abnormality occurs in the secondary battery due to overdischarge and the packaging member 13 expands, the conductor 27 does not slip due to the expansion of the packaging member 13.

  Furthermore, the conductor 27 is covered with an insulating material for protection from rust and the like. As the material of the insulating material 28, a material that is flexible and has heat resistance to withstand heat generation until the conductor 27 is broken, and excellent in electrical insulation, for example, polyimide is preferably used. Polyimide is less susceptible to distortion due to thermal expansion with metal wiring, and wiring processing is possible with high accuracy.

  In this embodiment, the example in which the conductor 27 is covered with the insulating material 28 has been described. However, the present invention is not limited to this. For example, the insulating material 28 positioned on the packaging member 13 side of the conductor 27 may be eliminated, and the conductor 27 may be directly bonded and fixed to the outer surface of the packaging member 13.

  The secondary battery 10 having such a configuration can be manufactured, for example, as follows. First, a precursor solution containing a solvent, an electrolyte salt, a polymer compound, and a mixed solvent is applied to each of the positive electrode 14 and the negative electrode 16, and the mixed solvent is volatilized to form a gel electrolyte. Next, the positive electrode terminal 12a is fixed to the end of the positive electrode current collector 14b by welding, and the negative electrode terminal 12b is fixed to the negative electrode current collector 16b by welding. And the positive electrode 14 and the negative electrode 16 in which the gel electrolyte was formed are laminated | stacked via separator 15a, 15b, and it is set as a laminated body. The laminate is wound in the longitudinal direction.

  Next, the battery element 11 is sealed with the packaging member 13 and stored. Specifically, first, the bulging portion 23 is formed on one surface of the packaging member 13 by deep drawing. The battery element 11 is housed in the bulging portion 23. Next, the packaging member 13 is folded and overlapped so that a part of the electrode terminal 12 of the battery element 11 is exposed and the opening surface of the bulging portion 23 is closed. Thereby, the superposition | polymerization part 24 with which the periphery of the packaging member 13 overlaps the circumference | surroundings (4 sides) of the battery element 11 is formed.

  Then, the peripheral portions (three sides continuous in a U-shape) of the packaging member 13 other than the folded side in the overlapped portion 24 are joined together by heat welding or an adhesive to seal the battery element 11. Of course, other joining methods can be used for this joining method. Next, the first overlapping portion 24a, which is the overlapping portion 24 and located on one side with the battery element 11 in between, is bent once toward the front portion 13a side of the bulging portion 23 to be bent first. A portion 26a is formed. Similarly, the second overlapping portion 24b, which is the overlapping portion 24 and is located on the other side of the battery element 11, is bent once toward the front portion 13a side of the bulging portion 23, and then the second bending portion. A portion 26b is formed.

  Next, the conductor 27 covered with the insulating material 28 is attached to the packaging member 13 that houses the battery element 11. That is, the conductor 27 is continuously passed along the width direction X on the outer surface of the packaging member 13 through the substantially central portion in the longitudinal direction Y of the front portion 13a, the left side portion 13d, and the back portion 13f. Wrap. Then, the insulating material 28 positioned on the packaging member 13 side of the conductor 27 is bonded to the fixing portions A and A at both ends in the width direction X of the front portion 13a and the fixing portions B and B at both ends in the width direction X of the back portion 13f. Glue and fix with. Thereby, the manufacturing process of the secondary battery 10 is completed.

  Next, the operation of the secondary battery 10 of the present invention having such a configuration will be described. Here, when the packaging member 13 expands, the conductor 27 is continuously wound from the front part 13a to the back part 13f, which is a large amount of deformation (volume increase) compared to other parts. ing. Further, in this embodiment shown in FIG. 1 and the like, as a preferred embodiment, the conductor 27 is wound along the width direction X at a substantially central portion in the longitudinal direction Y having the largest deformation amount in the packaging member 13. Is attached. The conductor 27 is fixed to the fixing portions A and A at both ends in the width direction X at the front surface portion 13a and the fixing portions B and B at both ends in the width direction X at the front surface portion 13a with an adhesive 29. It is configured.

  First, in a state where the secondary battery 10 is in a normal state, that is, in a state where charging / discharging is normally performed, as shown in FIGS. ing. At this time, since the packaging member 13 is not expanded, the force from the packaging member 13 does not act on the conductor 27. Therefore, the conductor 27 is wound around the packaging member 13 without being broken.

  Now, it is assumed that overdischarge occurs and the solvent constituting the battery element 11 is decomposed to generate gas. The packaging member 13 containing the battery element 11 is expanded by the gas generated at this time. In the substantially rectangular secondary battery 10 as in the present embodiment, as shown in FIGS. 6 and 7, the front portion 13 a and / or the back portion 13 f having a larger area than the other surfaces of the packaging member 13. Is the largest and swells in a dome shape. That is, the volume of the front part 13a and / or the back part 13f is increased, and the respective surface areas are increased. At this time, the conductor 27 is bonded and fixed to the fixing portions A, A, B, and B at both ends of the front surface portion 13a and the back surface portion 13f. Therefore, a tensile force in the linear direction acts on the conductor 27, and the stress becomes maximum at a substantially central portion between A-A and / or BB of the conductor 27.

  As shown in FIG. 6, when the expansion of the packaging member 13 is within a predetermined range, the maximum stress P <b> 1 applied to the approximate center between AA and BB of the conductor 27 is the allowable stress of the conductor 27. Is within the range. Therefore, the conductor 27 is not broken.

  Thereafter, when the expansion amount of the packaging member 13 further increases, the tensile force of the conductor 27 due to the expansion increases. And when the packaging member 13 expands beyond a predetermined range and the maximum stress P2 applied to the approximate center between AA and BB of the conductor 27 exceeds the allowable stress of the conductor 27, as shown in FIG. In addition, the conductor 27 breaks from the break portion 31 at the substantially center between AA and / or BB. Due to the breakage of the conductor 27, it can be detected that the secondary battery 10 is expanded and in an abnormal state.

  Next, a first example of the secondary battery device 1 of the present invention including the secondary battery 10 having the configuration and operation as described above will be described with reference to FIGS. As shown in FIG. 8, the secondary battery device 1 includes a secondary battery 10, an expansion detection circuit unit 2 that detects expansion of the secondary battery 10, and a circuit board 3 on which the expansion detection circuit unit 2 is mounted. Etc. are provided.

  The circuit board 3 is provided with two contact portions 3 a and 3 b connected to the electrode terminal 12. The contact portions 3a and 3b are connected to the electrode terminal 12 by resistance welding, ultrasonic welding, or the like. Each terminal piece of an output terminal (not shown) is electrically connected to the wiring pattern of the circuit board 3. This output terminal is detachably connected to various electronic devices (for example, a personal computer, a camera-integrated VTR, etc.) that are external devices. By the connection, the power of the secondary battery 10 constituting the secondary battery device 1 is supplied to the electronic device connected via the output terminal. Further, the circuit board 3 is equipped with an expansion detection circuit unit 2 that detects expansion of the secondary battery 10 from the breakage of the conductor 27.

  As illustrated in FIG. 9, the expansion detection circuit unit 2 includes a microcomputer 5 and a fuse 6. The microcomputer 5 is electrically connected to both terminal portions 27 a and 27 b of the conductor 27 wound around the packaging member 13 and energizes the conductor 27. The microcomputer 5 includes a control device, a processing device, a storage device, an input / output device, and the like.

  The abnormality detection mechanism of the secondary battery 10 in the secondary battery device 1 having such a configuration will be described with reference to the abnormality detection flowchart of FIG. First, the microcomputer 5 provided in the expansion detection circuit unit 2 monitors whether or not the conductor 27 is broken (cut), that is, the energization state of the conductor 27 (step S1). At this time, when the conductor 27 is not broken, the packaging member 13 is not expanded more than a predetermined value, and the secondary battery device 1 is operating normally. At this time, the microcomputer 5 and the conductor 27 are electrically connected.

  Next, for example, when overdischarge occurs and the solvent constituting the battery element 11 is decomposed to generate gas, the packaging member 13 that houses the battery element 11 is expanded by this gas. When the expansion amount is greater than or equal to a predetermined range, that is, when the stress acting on the conductor 27 due to this expansion becomes larger than the allowable stress of the conductor 27, the conductor 27 is broken. Then, conduction between the conductor 27 and the microcomputer 5 is interrupted. Thereby, the microcomputer 5 detects that the conductor 27 is broken. Based on this detection signal, the microcomputer 5 outputs a signal for cutting the fuse 6 as its control signal. As a result, the fuse 6 is cut, and the energization of the electric circuit including the fuse 6 is cut off (step S2).

  When the fuse 6 is cut, the secondary battery device 1 is in a state where the power of the secondary battery 10 cannot be output to the outside or the power from the outside cannot be input to the battery element 11. As a result, the secondary battery device 1 becomes unusable, and the secondary battery 10 is prevented from proceeding to an abnormal state.

  FIG. 11 shows a second embodiment of the secondary battery according to the present invention. The secondary battery 20 shown as the second embodiment is different from the secondary battery 10 according to the first embodiment in that the portion where the conductor 27 and the packaging member 13 are in contact with each other with the adhesive 29. It has just been bonded and fixed. For example, as shown in FIG. 11, the insulating material 28 covering the conductor 27 and the entire front surface portion 13 a, left side surface portion 13 d, and bottom surface portion 13 c of the packaging member 13 are bonded and fixed with an adhesive 29. . Since other configurations are the same as those of the secondary battery 10 according to the first embodiment, description thereof will be omitted.

  Even with the secondary battery 20 having such a configuration, the same effect as that of the secondary battery 10 according to the first embodiment described above can be obtained. In the case of the secondary battery 20 of this embodiment, since the entire portion where the conductor 27 and the packaging member 13 are in contact is fixed, the expansion of the packaging member 13 is detected substantially uniformly throughout the conductor 27. be able to. As a result, the expansion of the packaging member 13 can be detected with extremely high accuracy, and the abnormality of the secondary battery 20 can be detected quickly. Thereby, the safety | security of the secondary battery 20 and the electronic device which uses this secondary battery 20 as a portable power supply can be improved.

  FIG. 12 shows a third embodiment of the secondary battery according to the present invention. The secondary battery 30 shown as the third embodiment is different from the secondary battery 10 according to the first embodiment in that the conductor 27 is wound along the longitudinal direction Y of the packaging member 13. is there.

  Specifically, as shown in FIG. 12, the conductor 27 is arranged on the outer surface of the packaging member 13 along the longitudinal direction Y in the front portion 13 a, the rear portion 13 f, and the bottom portion 13 c in the width direction X. Wrapped around the center continuously. And the end 27a of the terminal part of the conductor 27 is pulled out from one end of the front part 13a on the upper surface part 13b side. The other end 27b of the terminal portion of the conductor 27 is drawn outward from one end of the back surface portion 13f on the upper surface portion 13b side. Since other configurations are the same as those of the secondary battery 10 according to the first embodiment, description thereof will be omitted. Even with the secondary battery 30 having such a configuration, the same effect as that of the secondary battery 10 according to the first embodiment described above can be obtained.

  FIG. 13 shows a fourth embodiment of the secondary battery according to the present invention. In the secondary battery 40 shown as the fourth embodiment, the conductor 27 is wound around the outer surface of the packaging member 13 along the width direction X for one or more rounds, specifically about 5/4 rounds. Is. That is, the conductor 27 is wound around the right side surface portion 13e and the front surface portion 13a continuously from the secondary battery 10 according to the first embodiment on the outer surface of the packaging member 13.

  One end 27a of the terminal portion of the conductor 27 in this embodiment is drawn outward from one end of the front surface portion 13a on the right side surface portion 13e side. The other end 27b of the terminal portion of the conductor 27 is drawn outward from the other end of the front surface portion 13a on the left side surface portion 13d side. Since other configurations are the same as those of the secondary battery 10 according to the first embodiment, description thereof will be omitted. Also with the secondary battery 40 having such a configuration, the same effect as that of the secondary battery 10 according to the first embodiment described above can be obtained.

  FIG. 14 shows a fifth embodiment of the secondary battery according to the present invention. In the secondary battery 50 shown as the fifth embodiment, the conductor 27 is disposed on the outer surface of the packaging member 13 along the width direction X over one and a half times, specifically, over approximately 7/4. Wrapped. That is, the conductor 27 is continuously wound around the outer surface of the packaging member 13 from the secondary battery 10 according to the first embodiment. Since other configurations are the same as those of the secondary battery 10 according to the first embodiment, description thereof will be omitted. Also with the secondary battery 50 having such a configuration, the same effect as that of the secondary battery 10 according to the first embodiment described above can be obtained. As shown in the fourth embodiment and the fifth embodiment, in the embodiment in which the conductor 27 is wound around the packaging member 13 over one turn or more, the expansion amount of the packaging member 13 is detected on four or more surfaces. be able to. As a result, the expansion amount of the packaging member 13 can be detected with relatively high accuracy.

  FIG. 15 shows a sixth embodiment of the secondary battery according to the present invention. The secondary battery 60 shown as an example of the sixth embodiment includes a front portion 13a of the front portion 13a and the rear portion 13f, which are portions where the amount of deformation of the conductor 27 increases when the packaging member 13 expands. It is wound so as to pass through only one side.

  That is, the conductor 27 is attached to the packaging member 13 so as to pass through substantially the center in the longitudinal direction Y of the front surface portion 13a, the left side surface portion 13d, and the right side surface portion 13e along the width direction X on the outer surface of the packaging member 13. It is in place. One end 27a of the terminal portion of the conductor 27 is drawn outward from one end 27a on the back surface portion 13f side of the left side surface portion 13d. The other end 27b of the terminal portion of the conductor 27 is drawn outward from one end of the right side surface portion 13e on the back surface portion 13f side.

  Then, the conductor 27 and the packaging member 13 are bonded and fixed with an adhesive 29 at two locations of the fixing portions A and A at both ends in the width direction X of the front portion 13a. The location where the conductor 27 and the packaging member 13 are bonded and fixed is not limited to the fixing portions A and A at both ends of the front portion 13a. For example, the lower end of each of the left side portion 13d and the right side portion 13e. The fixing portions C and C may be bonded and fixed. In addition, the conductor 27 passes through a portion where the amount of change (amount of increase in volume) is larger than that of the other portion when the packaging member 13 expands during the adhesive fixing. Position is preferred.

  Since other configurations are the same as those of the secondary battery 10 according to the first embodiment, description thereof will be omitted. Even in the secondary battery 60 having such a configuration, the conductor 27 is wound around the front portion 13a, which is a portion where the amount of change is large when the packaging member 13 expands. The same effects as those of the secondary battery 10 according to the embodiment can be obtained.

  As described above, according to the secondary battery and the secondary battery device of the present invention, the conductor is fixed to the packaging member in at least two places. As a result, when swelling occurs in the packaging member, a force in a pulling direction acts on the conductor from the approximate center between the two locations fixed to the packaging member to the outside. Thereby, even if it is one secondary battery, a conductor can be fractured | ruptured by the swelling of a packaging member, and the abnormality of a secondary battery can be detected. In addition, by suitably selecting the thickness, shape, material, etc. of the conductor, the allowable stress of the conductor with respect to the tensile force can be changed, and the allowable range of the expansion amount of the packaging member can be arbitrarily set. For example, by setting the conductor to be broken by a minute bulge of the packaging member, it is possible to detect the expansion of the packaging member with high accuracy and to quickly detect the abnormality of the secondary battery.

  The present invention is not limited to the embodiments described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, an example in which only one conductor is used has been described. However, two or more conductors may be used, which is suitable for a case where a plurality of secondary batteries are used or a large-sized secondary battery. is there.

  Moreover, in the said Example, although the secondary battery was demonstrated as a lithium ion battery, for example, a nickel hydrogen storage battery and other various secondary batteries may be sufficient. Furthermore, the secondary battery and the secondary battery device of the present invention can be applied to a mobile phone, a digital still camera, a personal computer, an electronic dictionary, a DVD player, and other various electronic devices.

It is a front view which shows the example of the 1st Example of the secondary battery of this invention. It is a side view which shows the example of the 1st Example of the secondary battery of this invention. It is a perspective view which shows the 1st Example of the secondary battery of this invention. It is a disassembled perspective view which shows the 1st Example of the battery element which concerns on the secondary battery of this invention. FIG. 4 is a cross-sectional view taken along the line TT of FIG. 3 showing a first example of the secondary battery of the present invention. FIG. 6A is a front view, FIG. 6B is a side view, and FIG. 6C is a plan view showing a state in which the packaging member in the first embodiment of the secondary battery of the present invention is expanded within a predetermined range. FIG. 7A is a front view, FIG. 7B is a side view, and FIG. 7C is a plan view showing a state in which the packaging member in the first embodiment of the secondary battery of the present invention has expanded beyond a predetermined range. It is a front view which shows the 1st Example of the secondary battery apparatus of this invention. It is explanatory drawing which shows typically the 1st Example of the expansion | swelling detection circuit part which concerns on the secondary battery apparatus of this invention. It is a flowchart which shows the 1st Example of the abnormality detection process which concerns on the secondary battery apparatus of this invention. It is explanatory drawing which cross-sections and shows the 2nd Example of the secondary battery of this invention. It is a perspective view which shows the 3rd Example of the secondary battery of this invention. It is explanatory drawing which shows typically the example of 4th Example of the secondary battery of this invention. It is explanatory drawing which shows typically the 5th Example of the secondary battery of this invention. It is explanatory drawing which shows typically the 6th Example of the secondary battery of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Secondary battery apparatus, 2 ... Expansion detection circuit part, 6 ... Fuse, 10, 20, 30, 40, 50, 60 ... Secondary battery, 11 ... Battery element, 12 ... Electrode terminal, 13 ... Packaging member, 27 …conductor

Claims (6)

A battery element having an electrode terminal;
A packaging member that exposes a part of the electrode terminal and seals and stores the battery element;
A conductor fixed at two or more locations on the outer surface of the packaging member so as to break when the packaging member expands;
A secondary battery comprising:   The secondary battery according to claim 1, wherein at least a part of the conductor is disposed in a portion where the volume of the packaging member increases when the packaging member expands.   2. The secondary battery according to claim 1, wherein the conductor is fixed to the packaging member with an adhesive at all of the portions in contact with the packaging member.   The secondary battery according to claim 1, wherein the conductor is a wire or a foil formed of a material capable of transmitting electricity. A battery element having an electrode terminal;
A packaging member that exposes a part of the electrode terminal and seals and stores the battery element;
A conductor fixed at two or more locations on the outer surface of the packaging member so as to break when the packaging member expands;
An expansion detection circuit unit that detects a breakage of the conductor from the energized state of the conductor and outputs a detection signal;
A secondary battery device comprising: A fuse connected to the electrode terminal is provided,
The secondary battery device according to claim 5, wherein the expansion detection circuit unit cuts the fuse based on a detection signal for detecting breakage of the conductor.

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