Battery Module

Abstract

To provide a battery module capable of improving safety of a whole solid battery.SOLUTION: A battery module comprises a plurality of cylindrical solid batteries 10. Each cylindrical solid battery 10 includes: a shaft center member 11; and a winding electrode group 12 in which an electrode lamination body in which a positive electrode and a negative electrode are laminated via an electrolyte is wound around the shaft center member 11. In the shaft center member 11, a NTC thermistor 14 is arranged between a first conductive member 11a and a second conductive member 11b in a shaft center direction, and a penetration hole T is formed to a center part. The cylindrical solid battery 10 further includes a temperature adjustment part that is arranged to the penetration hole T and adjusts a temperature of the NTC thermistor 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery module. [Background technology]

[0002] In recent years, research and development into secondary batteries that contribute to energy efficiency has been conducted to ensure that many people have access to affordable, reliable, sustainable and advanced energy.

[0003] Patent Document 1 describes a battery including a cylindrical core having an axial hole extending in the axial direction, and a wound electrode body formed by winding a first electrode plate, a second electrode plate, and a separator around the outer periphery of the core. Here, the axial hole is used as a path for discharging gas to the outside when the internal pressure of the battery increases and the safety valve opens. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-134641 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is a need to improve the safety of all-solid-state batteries.

[0006] An object of the present invention is to provide a battery module that can improve the safety of an all-solid-state battery. [Means for solving the problem]

[0007] One aspect of the present invention is a battery module comprising a plurality of cylindrical solid-state batteries, each of which has an axial core and a wound electrode group in which an electrode stack, in which a positive electrode and a negative electrode are stacked with an electrolyte interposed therebetween, is wound around the axial core, and the axial core has an NTC thermistor or a CTR thermistor disposed between a first conductive member and a second conductive member in the axial direction, and a through hole formed in the center, and the cylindrical solid-state battery is disposed in the through hole and further has a temperature adjustment unit that adjusts the temperature of the NTC thermistor or the CTR thermistor.

[0008] The cylindrical solid-state battery may further include a detection unit in the through-hole that detects a state of the cylindrical solid-state battery.

[0009] The cylindrical solid-state battery may have a first fastening portion provided at one end of the axial center member in the axial direction and a second fastening portion provided at the other end of the axial center member in the axial direction, and adjacent cylindrical solid-state batteries may be fastened via the first fastening portion and the second fastening portion.

[0010] The electrode stack may be formed by stacking the positive electrode and the negative electrode with a solid electrolyte layer interposed therebetween. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a battery module that can improve the safety of an all-solid-state battery. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a partially cutaway perspective cross-sectional view showing an example of a battery module according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing the cylindrical solid state battery of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] An example of a battery module according to this embodiment is shown in Fig. 1. Furthermore, Fig. 2 shows the cylindrical solid-state battery of Fig. 1.

[0015] The battery module 100 includes a plurality of cylindrical solid-state batteries 10. Here, each cylindrical solid-state battery 10 has an axial core member 11, a wound electrode group 12 in which an electrode stack, in which positive electrodes and negative electrodes are stacked with an electrolyte interposed therebetween, is wound around the axial core member 11, and a male screw portion 13A as a first fastening portion provided at one (upper) end of the axial core member 11 in the axial direction, and a female screw portion 13B as a second fastening portion provided at the other (lower) end of the axial core member 11 in the axial direction. In the battery module 100, adjacent cylindrical solid-state batteries 10 are connected via the male screw portion 13A and the female screw portion 13B.

[0016] In this case, the male screw portion 13A is molded integrally with the shaft core member 11. This improves the strength against the rotational torque when fastening the male screw portion 13A and the female screw portion 13B. The male screw portion 13A is electrically connected to one of the positive electrode and the negative electrode, and the female screw portion 13B is electrically connected to the other of the positive electrode and the negative electrode.

[0017] The first fastening portion may be a female thread portion, and the second fastening portion may be a male thread portion.

[0018] The axial member 11 has an NTC thermistor 14 disposed between the first conductive member 11a and the second conductive member 11b in the axial direction, and a through-hole T formed in the center. The cylindrical solid-state battery 10 is disposed in the through-hole T and further has a temperature adjustment unit that adjusts the temperature of the NTC thermistor 14. Therefore, when the cylindrical solid-state battery 10 is in an abnormal state (for example, when the voltage is high), the temperature adjustment unit heats the NTC thermistor 14, thereby reducing the resistance of the NTC thermistor 14 and making it conductive. As a result, the voltage of the cylindrical solid-state battery 10 with a high voltage becomes the same as that of the conductive cylindrical solid-state battery 10, and the voltage drops.

[0019] Based on the same principle as above, when manufacturing the battery module 100, after the cylindrical solid-state batteries 10 are connected, the temperature adjustment unit heats the NTC thermistor 14, thereby reducing the resistance of the NTC thermistor 14 and making it conductive, thereby eliminating variations in the voltage of the multiple cylindrical solid-state batteries 10.

[0020] In the cylindrical solid state battery 10, the temperature adjustment unit may cool the NTC thermistor 14. This allows the heated NTC thermistor 14 to return to the state before it was heated.

[0021] The temperature adjusting unit is not particularly limited, but examples thereof include a water-cooled cooling device, an air-cooled cooling device, an electric heating material such as a metal or a heat pipe, or a heating device in which a heating resistor is installed on a circuit, and two or more of these may be used in combination.Furthermore, the heating device is not particularly limited, but examples thereof include a coiled electric heating wire, a ceramic resistor, a device having a circuit in which a PTC heater element is installed, and the like.

[0022] At this time, the NTC thermistor 14 is fastened to the first conductive member 11a and the second conductive member 11b. This compresses the insulating member 17, which will be described later, improving the sealing performance of the cylindrical solid state battery 10. Here, the first conductive member 11a has a female thread portion at its lower end in the axial direction. The NTC thermistor 14 has a male thread portion at its upper end in the axial direction, and a female thread portion at its lower end in the axial direction. Furthermore, the second conductive member 11b has a male thread portion at its upper end in the axial direction.

[0023] The arrangement of the male and female threaded portions of the first conductive member 11a, the second conductive member 11b, and the NTC thermistor 14 is not particularly limited as long as it is possible to fasten the first conductive member 11a, the second conductive member 11b, and the NTC thermistor 14.

[0024] Furthermore, the first conductive member 11a and the second conductive member 11b may be fitted together with the NTC thermistor 14 interposed therebetween.

[0025] The material forming the first conductive member 11a and the second conductive member 11b is not particularly limited, but examples thereof include metals. The material forming the NTC thermistor 14 is not particularly limited, but examples thereof include bandgap semiconductors such as SiC and Si. Examples of the NTC thermistor 14 include devices in which these materials are disposed as part of an insulator and which have a mechanism for sensing temperature and causing a minute current to flow.

[0026] Instead of the NTC thermistor 14, a CTR thermistor may be used.

[0027] The cylindrical solid-state battery 10 may further include a detection unit in the through hole T that detects the state of the cylindrical solid-state battery 10. In this case, when the detection unit detects that the state of the cylindrical solid-state battery 10 is abnormal, a current is passed through the resistance heating element to heat the NTC thermistor 14, causing the resistance of the NTC thermistor 14 to decrease and become conductive.

[0028] The detector is not particularly limited as long as it can detect that the cylindrical solid state battery 10 is in an abnormal state, and examples thereof include a voltage sensor, a temperature sensor, and a calorific sensor.

[0029] The electrode laminate is in a sheet form, and each electrode has an electrode mixture layer formed on an electrode current collector. That is, the positive electrode has a positive electrode mixture layer formed on a positive electrode current collector, and the negative electrode has a negative electrode mixture layer formed on a negative electrode current collector. The electrolyte is not particularly limited, and may be contained in, for example, a gel electrolyte layer or a solid electrolyte layer.

[0030] The electrode laminate may have a plurality of positive electrodes and / or negative electrodes, as long as the positive electrodes and negative electrodes are stacked with the electrolyte interposed therebetween. Examples of the stack structure of an electrode laminate having a plurality of positive electrodes and / or negative electrodes include positive electrode / electrolyte / negative electrode / electrolyte / positive electrode. In this case, the electrode laminate can be produced by, for example, roll pressing.

[0031] The cylindrical solid state battery 10 further includes an exterior member 15 that winds the wound electrode group 12. Here, the exterior member 15 is sheet-shaped. The material that forms the exterior member 15 is not particularly limited as long as it is conductive, and examples thereof include metals.

[0032] In this case, exterior member 15 may be bonded with an adhesive to the end of wound electrode group 12 on the side not in contact with shaft member 11, or may be an electrode current collector extending from the end of wound electrode group 12 on the side not in contact with shaft member 11. This improves the volumetric energy density of battery module 100.

[0033] The wound electrode group 12 wound with the exterior member 15 is obtained by winding the electrode stack and the exterior member 15 around the axial core member 11 while applying a predetermined tension. At this time, the electrode stack and the exterior member 15 may be wound while pressing the axial core member 11 from the outside.

[0034] The cylindrical solid-state battery 10 further includes a first lid member 16A disposed at one (upper) end in the axial direction and electrically connected to one of the positive and negative electrodes, and a second lid member 16B disposed at the other (lower) end in the axial direction and electrically connected to the other of the positive and negative electrodes. The first lid member 16A and the second lid member 16B each have an inclined region that is inclined approximately symmetrically with respect to the axial member 11 and have a conical outer shape. A ring-shaped insulating member 17 is disposed between the exterior member 15 and the first lid member 16A. The first lid member 16A is electrically connected to the male thread portion 13A, and the second lid member 16B is electrically connected to the female thread portion 13B and the exterior member 15.

[0035] There are no particular limitations on the angle of inclination of the inclined regions of first cover member 16A and second cover member 16B relative to shaft member 11. The angle of inclination of the inclined region of first cover member 16A relative to shaft member 11 is determined by the height of extension portion 18A adjacent to the side of shaft member 11 of wound electrode group 12 and the width determined by the number of turns of wound electrode group 12. Furthermore, the inclined region of first cover member 16A has a volume that can accommodate extension portion 18A.

[0036] The material that makes up first lid member 16A and second lid member 16B is not particularly limited as long as it is conductive, and examples include metal, etc. The materials that make up first lid member 16A and second lid member 16B may be the same or different.

[0037] Furthermore, the insulating member 17 is compressed by the fastening force between the male screw portion 13A provided at the upper end in the axial direction of the axial core member 11 and the female screw portion 13B provided at the lower end in the axial direction of the axial core member 11, and as a result, the exterior member 15 and the first cover member 16A are fixed and sealed together. Meanwhile, the contact portion of the second cover member 16B with the exterior member 15 is joined by laser welding, and they are sealed and integrated together.

[0038] The material constituting the insulating member 17 is not particularly limited, but examples thereof include resins such as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), and PFA.

[0039] The positive electrode current collector has an extending portion 18A extending from one (upper) end in the axial direction of the wound electrode group 12, and the negative electrode current collector has an extending portion 18B extending from the other (lower) end in the axial direction of the wound electrode group 12. Here, extending portion 18A of the positive electrode current collector collects current to first cover member 16A, and extending portion 18B of the negative electrode current collector collects current to second cover member 16B.

[0040] At this time, the second cover member 16B electrically connected to the extension portion 18B that collects current on the exterior member 15 has a larger inclination angle of the inclined region than the first cover member 16A electrically connected to the extension portion 18A that collects current on the shaft center member 11. This makes it easier to connect adjacent cylindrical solid state batteries 10 via the male screw portion 13A and the female screw portion 13B.

[0041] Hereinafter, a case will be described in which the cylindrical solid state battery constituting the battery module of this embodiment is an all-solid state lithium secondary battery.

[0042] The positive electrode current collector is not particularly limited, but may be, for example, aluminum foil.

[0043] The positive electrode mixture layer contains a positive electrode active material, and may further contain a solid electrolyte, a conductive additive, a binder, and the like.

[0044] The positive electrode active material is not particularly limited as long as it can absorb and release lithium ions. For example, LiCoO2, Li(Ni 5 / 10 Co 2 / 10 Mn 3 / 10 )O 2、 Li(Ni) 6 / 10 Co 2 / 10 Mn 2 / 10 )O 2、 Li(Ni)8 / 10 Co 1 / 10 Mn 1 / 10 )O 2、 Li(Ni) 0.8 Co 0.15 Al 0.05 )O 2、 Li(Ni) 1 / 6 Co 4 / 6 Mn 1 / 6 )O 2、 Li(Ni) 1 / 3 Co 1 / 3 Mn 1 / 3 )O 2、 Examples include LiCoO4, LiMn2O4, LiNiO2, LiFePO4, lithium sulfide, and sulfur.

[0045] The solid electrolyte constituting the solid electrolyte layer is not particularly limited as long as it is a material capable of conducting lithium ions, and examples thereof include oxide-based electrolytes, sulfide-based electrolytes, and molecular crystalline electrolytes in which the electrolyte is dissociated into crystalline bodies made of organic substances.

[0046] The negative electrode mixture layer contains a negative electrode active material, and may further contain a solid electrolyte, a conductive additive, a binder, and the like.

[0047] The negative electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium ions, and examples thereof include metallic lithium, lithium alloys, metal oxides, metal sulfides, metal nitrides, Si, SiO, carbon materials, etc. Examples of carbon materials include artificial graphite, natural graphite, hard carbon, soft carbon, etc.

[0048] The negative electrode current collector is not particularly limited, but examples thereof include copper foil.

[0049] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the above-described embodiments may be modified as appropriate within the scope of the spirit of the present invention. [Explanation of symbols]

[0050] 10 Cylindrical solid-state battery 11 Shaft core member 11a First conductive member 11b Second conductive member 12-wound electrode group 13A male thread 13B female thread 14 NTC thermistor 15 Exterior materials 16A First cover member 16B Second cover member 17 Insulating material 18A, 18B extension part 100 Battery Module T through hole

Claims

1. A plurality of cylindrical solid-state batteries are provided, the cylindrical solid-state battery includes a shaft member and a wound electrode group in which an electrode stack, in which a positive electrode and a negative electrode are stacked with an electrolyte interposed therebetween, is wound around the shaft member; the shaft core member has an NTC thermistor or a CTR thermistor disposed between a first conductive member and a second conductive member in the axial direction, and a through hole formed in the center thereof; The cylindrical solid-state battery is disposed in the through-hole, and the battery module further includes a temperature adjusting unit that adjusts the temperature of the NTC thermistor or the CTR thermistor.

2. The battery module according to claim 1 , wherein the cylindrical solid-state battery further includes a detector in the through-hole that detects a state of the cylindrical solid-state battery.

3. the cylindrical solid-state battery has a first fastening portion provided at one end of the shaft member in the axial direction and a second fastening portion provided at the other end of the shaft member in the axial direction, The battery module according to claim 1 , wherein adjacent cylindrical solid-state batteries are fastened together via the first fastening portion and the second fastening portion.

4. The battery module according to claim 1 , wherein the electrode stack is formed by stacking the positive electrode and the negative electrode with a solid electrolyte layer interposed therebetween.

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