Secondary batteries

Abstract

One aspect of the present invention provides a highly safe secondary battery monitoring system that detects abnormalities in secondary batteries, for example, early detection of phenomena that reduce the safety of the secondary battery, and alerts the user, thereby ensuring safety. [Solution] A monitoring system uses an imaging device to capture the exterior of a secondary battery. Furthermore, to facilitate detection of abnormalities, a temperature-sensitive paint is sprayed or painted onto at least a portion of the surface of the secondary battery's exterior body. A light source is also provided to irradiate the temperature-sensitive paint. With this configuration, if abnormal heat is generated locally, the abnormal area can be made to emit light (or develop color), and the abnormal area can be identified from the image data using the imaging device. Therefore, danger can be detected from the image data before a fire or explosion occurs.

Description

[Technical Field]

[0001] One embodiment of the present invention relates to an object, a method, or a manufacturing method. Alternatively, the present invention relates to a process, a machine, a manufacture, or a composition of matter. One embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, or an electronic device, or a manufacturing method thereof. Another embodiment of the present invention relates to a method for estimating a state of charge of a power storage device, a system for estimating a state of charge of a power storage device, and a method for detecting an abnormality. In particular, the present invention relates to a system for estimating a state of charge of a power storage device and a system for detecting an abnormality of a power storage device.

[0002] In this specification, the term "power storage device" refers to all elements and devices having a power storage function, including, for example, lithium ion secondary battery storage batteries (also called secondary batteries), lithium ion capacitors, nickel-metal hydride batteries, all-solid-state batteries, and electric double layer capacitors.

[0003] Furthermore, an anomaly detection system can be configured using AI (Artificial Intelligence), and one embodiment of the present invention relates to a neural network and an anomaly detection system for a power storage device using the neural network. Another embodiment of the present invention relates to a vehicle using the neural network. Another embodiment of the present invention relates to an electronic device using the neural network. Another embodiment of the present invention relates to an equipment anomaly detection system that is not limited to vehicles and can also be applied to a power storage device for storing power obtained from a power generation facility of a solar power generation panel installed on a structure.

[0004] In this specification, the term "power storage device" refers to all elements and devices having a power storage function, including, for example, lithium ion secondary battery storage batteries (also called secondary batteries), lithium ion capacitors, nickel-metal hydride batteries, all-solid-state batteries, and electric double layer capacitors. [Background technology]

[0005] 2. Description of the Related Art Electronic devices that are carried by or worn by users have been actively developed.

[0006] Electronic devices carried by users or worn by users operate using primary or secondary batteries, which are examples of power storage devices, as their power source. It is desirable for electronic devices carried by users to be used for long periods of time, and for this purpose, large-capacity secondary batteries are used. However, incorporating a large-capacity secondary battery into an electronic device poses the problem of its large size and weight. Therefore, development is underway to develop small or thin, large-capacity secondary batteries that can be incorporated into portable electronic devices.

[0007] Demand for high-power, high-energy-density lithium-ion secondary batteries is expanding rapidly in particular, along with the development of mobile phones, smartphones, portable information terminals such as laptop computers, portable music players, digital cameras, medical equipment, next-generation clean energy automobiles such as hybrid vehicles (HVs), electric vehicles (EVs), and plug-in hybrid vehicles (PHVs), and the semiconductor industry, making them an indispensable source of rechargeable energy in today's information society.

[0008] While lithium ion secondary batteries have a large capacity, there is a risk that the temperature inside the battery will rise if abnormal heat is generated due to an internal short circuit or overcharging.

[0009] Patent Document 1 discloses a charge control circuit that detects when the ambient temperature of the battery of an electric vehicle is outside of a normal operating range and controls the temperature to within an appropriate range. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] WO2020 / 084386 Summary of the Invention [Problem to be solved by the invention]

[0011] Regular secondary batteries are inspected before shipping, and any secondary batteries that develop abnormalities are removed. Improvements in secondary battery manufacturing technology have reduced the number of secondary batteries that develop abnormalities. However, it is difficult to reduce the number of secondary batteries that develop abnormalities after long-term use to zero.

[0012] An object of the present invention is to provide a secondary battery that makes it easy to detect abnormalities.

[0013] One of the objectives is to ensure safety by detecting abnormalities in secondary batteries non-destructively, for example by detecting phenomena that reduce the safety of secondary batteries at an early stage and warning users.

[0014] Another object of the present invention is to provide a highly safe secondary battery monitoring system. [Means for solving the problem]

[0015] In order to provide a highly safe monitoring system for secondary batteries, the monitoring system uses an imaging device that photographs the exterior of the secondary battery.

[0016] Furthermore, to facilitate detection of abnormalities, a temperature-sensitive paint is sprayed or painted on at least a portion of the surface of the secondary battery's exterior. A light source is also provided to illuminate the temperature-sensitive paint. This configuration allows the abnormal area to emit light (or color) when abnormal heat occurs locally, and the abnormal area can be identified from image data using an imaging device. Therefore, risk can be detected from the image data before a fire or explosion occurs. The image data can be either still or video data. Video data can be used to determine the risk based on the rate of temperature increase per unit time. In lithium-ion secondary batteries, the negative electrode and electrolyte react when temperatures exceed 80°C; the separator melts and short-circuits when temperatures exceed 140°C; and the positive electrode material thermally decomposes, releasing oxygen, which combusts violently with the vaporized electrolyte when temperatures exceed 200°C, resulting in a phenomenon known as thermal runaway. In the case of lithium-ion secondary batteries, it is necessary to accurately determine whether there are signs of thermal runaway between 45°C and 80°C, the temperature at which the electrolyte and negative electrode begin to react, or whether the temperature is simply rising by chance due to current discharge.

[0017] The invention disclosed in this specification is a secondary battery having a positive electrode, a negative electrode, and an exterior body that surrounds at least a portion of the positive electrode and the negative electrode, and having a temperature-sensitive paint on the surface of the exterior body.

[0018] In the above configuration, the exterior body is a housing made of a laminate film or metal.

[0019] Furthermore, to create a highly safe secondary battery monitoring system, multiple types of monitoring systems can be combined. For example, it can be combined with a method of monitoring the internal temperature of the secondary battery. The T terminal (temperature detection terminal) provided on the battery pack is the analog signal output terminal of the temperature sensor, and a thermistor is connected between the negative terminal and the T terminal. The resistance value of the thermistor is detected by a circuit, and charging is stopped if the resistance value is outside the range. The temperature is calculated from this resistance value.

[0020] In addition, image data of the exterior body of the secondary battery, and the internal temperature, voltage, and current of the secondary battery can be used as learning data to train a neural network unit, and locations of abnormal heat generation can be estimated. Examples of locations of abnormal heat generation include heat generation due to bending of the current collector caused by an impact, and internal short circuits caused by dendrites that occur during charging in a low-temperature environment.

[0021] In this specification, a monitoring system using a neural network unit is also one of the inventions, and is configured to include a secondary battery having a positive electrode, a negative electrode, and an exterior body that surrounds at least a portion of the positive electrode and the negative electrode, a light source that irradiates light onto the exterior body, an imaging device that images the surface of the exterior body, and a neural network unit that estimates abnormal heat generation on the surface of the exterior body, and is a monitoring system for a secondary battery that images temperature changes on the surface of the exterior body using the imaging device and estimates an abnormality in the secondary battery.

[0022] In the above monitoring system, the exterior body of the secondary battery has a temperature-sensitive paint on the surface of the exterior body. If a tendency for abnormal heat generation to occur locally appears before thermal runaway occurs, the abnormal area can be made to emit light (or develop color), thereby making it possible to identify the abnormal area and the secondary battery that has an abnormality.

[0023] In addition, in the above monitoring system, the data learned by the neural network unit and the data of the secondary battery are one or more selected from image data captured by an imaging device, the internal temperature of the secondary battery, and the voltage, power, and current of the secondary battery.

[0024] Abnormal heat generation in secondary batteries, which is difficult to predict, can lead to serious accidents such as fires. This can be particularly life-threatening in vehicles. Vehicles often contain many secondary batteries. Abnormal heat generation in secondary batteries installed in homes or factories can also be life-threatening. It is also desirable to monitor secondary batteries in vehicles or homes 24 hours a day. Using a neural network section enables accurate monitoring while eliminating noise.

[0025] It is also desirable to be able to remotely identify the location of an abnormality after abnormal heat generation occurs. By installing an imaging device near the secondary battery and transmitting the image data, abnormal heat generation can be identified remotely. Therefore, even without installing a large-scale arithmetic circuit in the electric vehicle, image data can be transmitted and the abnormality analyzed at the car dealer, with the results being received by the electric vehicle and the driver, allowing them to take action. Because electric vehicles pose a risk of electric shock if handled improperly, drivers should avoid directly checking for abnormalities. This invention offers significant advantages in terms of maintenance, as it allows the condition of the secondary battery to be instantly confirmed using data from an imaging device that captures the exterior of the secondary battery.

[0026] The configuration of the present invention enables monitoring of image data using an imaging device, and more accurate abnormality detection can be performed while also monitoring electrical characteristic data. Therefore, abnormal secondary batteries can be detected in advance more reliably than in the past. [Effects of the Invention]

[0027] By using a secondary battery with a temperature-sensitive paint sprayed or painted on at least a portion of the exterior surface, it becomes possible to identify abnormal heat generation in advance using an imaging device. Furthermore, by monitoring using a neural network unit rather than by the driver, safety is further improved. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is an example of a block diagram illustrating one embodiment of the present invention. [Figure 2] FIG. 2A is a diagram illustrating the appearance of a secondary battery according to one embodiment of the present invention, and FIG. 2B is an example of a cross-sectional structure thereof. [Figure 3] Figure 3A shows an example of a cylindrical secondary battery, Figure 3B shows an example of a cylindrical secondary battery, and Figure 3C shows an example of a plurality of cylindrical secondary batteries. [Figure 4]4A and 4B are diagrams illustrating an example of a secondary battery, and FIG. 4C is a diagram showing the inside of the secondary battery. [Figure 5] 5A to 5C are diagrams illustrating an example of a secondary battery. [Figure 6] FIG. 6 is a diagram showing an example of a flow diagram of the monitoring system. [Figure 7] 7A to 7E are diagrams illustrating an example of a transportation vehicle. [Figure 8] 8A and 8B illustrate a power storage device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various modifications can be made to the embodiments and details. Furthermore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0030] In this specification, "charging" refers to the transfer of lithium ions from the positive electrode to the negative electrode within a battery and the transfer of electrons from the positive electrode to the negative electrode in an external circuit. Regarding a positive electrode active material, "charging" refers to the removal of lithium ions. A positive electrode active material with a charge depth of 0.7 to 0.9 is sometimes referred to as a positive electrode active material charged at a high voltage.

[0031] Similarly, discharging refers to the transfer of lithium ions from the negative electrode to the positive electrode within the battery and the transfer of electrons from the negative electrode to the positive electrode in an external circuit. For positive electrode active materials, discharging refers to the insertion of lithium ions. A fully discharged positive electrode active material is defined as a positive electrode active material with a charge depth of 0.06 or less, or a positive electrode active material that has been discharged to 90% or more of its charge capacity from a high-voltage charged state.

[0032] A secondary battery has, for example, a positive electrode and a negative electrode. A material constituting the positive electrode is a positive electrode active material. The positive electrode active material is, for example, a substance that undergoes a reaction that contributes to the charge / discharge capacity. Note that the positive electrode active material may partially contain a substance that does not contribute to the charge / discharge capacity.

[0033] In this specification, the positive electrode active material of one embodiment of the present invention may be referred to as a positive electrode material or a positive electrode material for a secondary battery. Also, in this specification, the positive electrode active material of one embodiment of the present invention preferably includes a compound. Also, in this specification, the positive electrode active material of one embodiment of the present invention preferably includes a composition. Also, in this specification, the positive electrode active material of one embodiment of the present invention preferably includes a composite.

[0034] Discharge rate is the relative ratio of the current during discharge to the battery capacity, and is expressed in units of C. For a battery with a rated capacity of X (Ah), the current equivalent to 1C is X (A). When discharging at a current of 2X (A), it is said to have been discharged at 2C, and when discharging at a current of X / 5 (A), it is said to have been discharged at 0.2C. The same is true for charge rate; when charging at a current of 2X (A), it is said to have been charged at 2C, and when charging at a current of X / 5 (A), it is said to have been charged at 0.2C.

[0035] Constant current charging, for example, refers to a method of charging at a constant charge rate. Constant voltage charging, for example, refers to a method of charging at a constant voltage once the upper voltage limit is reached. Constant current discharging, for example, refers to a method of discharging at a constant discharge rate.

[0036] (Embodiment 1) In this embodiment, an example of a monitoring system 150 according to one embodiment of the present invention will be described with reference to FIG.

[0037] 1 is a block diagram of a monitoring system 150, which has multiple devices for monitoring a secondary battery 101 and for estimating the occurrence of an abnormality. The secondary battery 101 is shown as an example in which a charge control circuit 102, an ammeter 103, a voltmeter 104, and an internal temperature sensor 105 are electrically connected to each other.

[0038] Although FIG. 1 shows only one secondary battery 101, electric vehicles typically have multiple secondary batteries 101 mounted on them, which are connected in series or parallel, equipped with a protection circuit, and used as a battery pack (also called a battery assembly). A battery pack refers to a configuration in which multiple secondary batteries 101 are housed together with a predetermined circuit inside an exterior body (metal can, film exterior body (also called laminate film)) to facilitate handling of the secondary batteries 101. The battery pack is equipped with an ECU (Electronic Control Unit) to manage its operating state.

[0039] Furthermore, one ammeter 103 or one voltmeter 104 is often provided for each of a plurality of secondary batteries, and one charge control circuit 102 may be provided for all of the secondary batteries.

[0040] An imaging device 111 capable of capturing an image of the exterior of the secondary battery 101 can obtain image data by turning on a light source 113 .

[0041] In particular, when the monitoring system 150 is installed in an electric vehicle, if a collision occurs due to some kind of accident, it is preferable that the driver check the appearance of the secondary battery 101 while the vehicle is stopped and visually check whether there is an abnormality on the display unit 109. If an abnormality is confirmed through visual inspection, the imaging device can be driven by a power source other than the secondary battery 101, allowing the driver to safely get off the vehicle without using the secondary battery 101 in which the abnormality has been confirmed. Furthermore, safety can be ensured by starting the power supply to the secondary battery 101 of the electric vehicle after visually confirming that the secondary battery 101 is normal. Furthermore, in a traffic accident involving an electric vehicle, there is a risk that the secondary battery will explode after a collision, and it may be unclear how the accident occurred, whether the explosion occurred before the collision or after the collision. By installing the monitoring system 150 in an electric vehicle, it is possible to image the secondary battery like a drive recorder, so that the system can capture an image simultaneously with impact detection, record image data, or transmit the image data to a car dealer.

[0042] Furthermore, the imaging device 111 can be used to visually check the impact on the secondary battery 101 when an electric vehicle is submerged in water. When a gasoline-powered vehicle is driven on a flooded road, water enters the exhaust port, preventing the vehicle from venting and rendering it unable to run. However, an electric vehicle can still run if there is no water inside the battery pack, which is located in a sealed space, and the electrical cables are not exposed. Furthermore, if the imaging device 111 detects that water has entered the battery pack, the driver can determine that it is safe to not operate the secondary battery 101. In the case of an electric vehicle, an inert gas, such as nitrogen gas, may be filled in a sealed space, and the imaging device, light source, and battery pack may be placed therein. Because oxygen around the battery pack may promote a reaction, the area around the battery pack may be filled with nitrogen gas or argon gas to further enhance safety.

[0043] To improve visibility, a temperature-sensitive paint is sprayed or painted onto at least a portion of the surface of the exterior body of the secondary battery 101. When a temperature-sensitive paint is used, an LED light source with a wavelength of 470 nm is used as the light source 113. When the temperature-sensitive paint is irradiated with excitation light of a specific wavelength (wavelength range of 400 nm to 600 nm), the paint emits light, and the luminescence intensity depends on the temperature of the paint-coated surface. The temperature-sensitive paint is composed of dye molecules, a binder, and a solvent, and its characteristics are determined by the combination of the dye and the binder. The dye for the temperature-sensitive paint is a polycyclic aromatic hydrocarbon such as rhodamine B, a ruthenium complex, or a europium complex. The binder is preferably an oxygen-impermeable resin material, such as polymethacrylate, polyurethane, or polyacrylic acid. An organic solvent, such as ethanol, is used as the solvent, and the temperature-sensitive paint is applied by spraying.

[0044] The area of ​​the secondary battery to which the temperature-sensitive paint is applied is the side or top surface of the exterior body of the secondary battery 101. Therefore, the imaging device 111 captures an image of a portion of the surface of the exterior body of the secondary battery 101 and monitors its temperature. The imaging device 111 monitors the temperature of the surface of the exterior body of the secondary battery 101, specifically the heat generation state in the range of 45°C to 80°C.

[0045] When monitoring an electric vehicle while it is stopped, the power source for the imaging device 111, light source 113, and display unit 109 is supplied with power not from the secondary battery 101 but from another power source (for example, a lead-acid battery). In this way, monitoring can be performed not only when the secondary battery 101 is being charged or discharged, but also when the power supply to the secondary battery is stopped. The light source 113 may be constantly lit, but may also be lit only when the imaging device 111 is capturing an image to reduce power consumption. When monitoring an electric vehicle while it is stopped, it can also be called a vehicle condition diagnosis system that diagnoses the condition of the secondary battery 101.

[0046] Furthermore, when monitoring an electric vehicle while it is running, the power supplies of the imaging device 111, light source 113, and display unit 109 may be switched so that power is supplied from the secondary battery 101. The power supply is switched by a data processing unit (not shown). The data processing unit has a CPU (Central Processing Unit), ROM, and RAM, and the CPU reads out a program corresponding to the processing content from the storage unit or ROM, loads it into the RAM, and executes the loaded program to perform predetermined processing.

[0047] Furthermore, the internal resistance of the secondary battery 101 is temperature dependent, and can therefore be monitored by the internal temperature sensor 105. Of course, it is possible to measure the temperature of the secondary battery 101 by the internal temperature sensor 105 without using the imaging device 111, but this is insufficient from the standpoint of safety due to the risk of the temperature sensor failing or the limited sensing area.

[0048] The internal temperature sensor 105 monitors the temperature inside the secondary battery 101. By using the internal temperature sensor 105 together with the imaging device 111, the monitoring system 150 can be made safer.

[0049] Furthermore, the output current of the secondary battery 101 can be measured by an ammeter 103, and the output voltage of the secondary battery 101 can be measured by a voltmeter 104. Of course, it is possible to detect an abnormality based on the electrical characteristic values ​​obtained by the ammeter 103 or voltmeter 104 without using the imaging device 111, but this is insufficient from a safety standpoint. In many cases, one ammeter 103 or voltmeter 104 is provided for each of multiple secondary batteries, making it difficult to identify only the secondary battery with an abnormality. Using the ammeter 103 or voltmeter 104 in combination with the imaging device 111 can make the monitoring system 150 safer.

[0050] Furthermore, the temperature of the secondary battery 101 may be adjusted by a heat sink or heater temperature adjustment mechanism 112. Because the heater is not coated with temperature-sensitive paint, the image capture device 111 will not detect the heater temperature and make an erroneous determination. The temperature-sensitive paint can be applied selectively, which has the advantage of allowing selective monitoring. Furthermore, the secondary battery 101 may be cooled or heated by the temperature adjustment mechanism 112 based on image data of the image capture device 111 obtained by the light emission of the temperature-sensitive paint.

[0051] Furthermore, neural network processing can be performed based on image data obtained by the imaging device 111 to estimate the occurrence of an abnormality.

[0052] In this case, a single IC chip that integrates a GPU (Graphics Processing Unit) and a PMU (Power Management Unit) will be used instead of the electric vehicle's CPU.

[0053] The software program that executes the inference program for performing the neural network processing of the above estimation can be written in various programming languages, such as Python, Go, Perl, Ruby, Prolog, Visual Basic, C, C++, Swift, Java (registered trademark), and .NET. The application may also be created using the frameworks Chainer (available for Python), Caffe (available for Python and C++), and TensorFlow (available for C, C++, and Python).

[0054] The monitoring system 150 is an operating environment that can run at least Python software.

[0055] It is desirable for an estimation device to perform estimation using as little data as possible and output highly accurate estimated values. If the amount of data is small, the amount of learning data to be stored can be reduced, and the memory capacity required to store it can be reduced. Furthermore, if the amount of data is small, the time required for calculation processing can be shortened.

[0056] The neural network unit 106 is realized by software calculations using a microcontroller. A microcontroller is a computer system built into a single integrated circuit (IC). When the scale of calculations or the amount of data to be handled is large, the neural network unit 106 may be configured by combining multiple ICs. Furthermore, a microcontroller equipped with Linux (registered trademark) is preferable because it allows the use of free software, thereby reducing the total cost for configuring the neural network unit 106. Furthermore, other operating systems (OSs) may be used instead of Linux (registered trademark).

[0057] The learning of the neural network unit 106 shown in FIG. 1 will be described below.

[0058] The program is created using Python under a Linux (registered trademark) operating environment. Image data obtained from the imaging device 111 is used as learning data. Image data during charging or discharging is accumulated, and the tendency of changes in the image data due to temperature changes is analyzed and weighted. The weights function as a filter. For example, a convolution filter of a convolutional neural network (CNN) can be used as the filter. Alternatively, an image processing filter such as an edge extraction filter can be used. Data on the current value, voltage value, and internal temperature during charging can also be added to the learning data. Data on the current value, voltage value, and internal temperature during discharging can also be added to the learning data. Based on this learning data, the neural network unit 106 estimates whether or not there is an abnormality.

[0059] Once the neural network unit 106 completes its estimation, the determination unit 107 compares the estimated value with a reference value to detect an anomaly. The reference value may be selected from several reference values ​​previously stored in a lookup table in the storage unit 108. The data stored in the lookup table is data that associates inputs with outputs. The data includes an array of multiple parameters, serving as a comparison table. The lookup table may also include a lookup table that associates inputs with outputs using mathematical functions. If the estimated value differs significantly from the reference value and an anomaly is determined to exist, the monitoring system 150 may display an anomaly detection message on the display unit 109. The display unit 109 may be shared with the display unit of the car navigation device, so that the driver can be alerted by simultaneously displaying a map and displaying an anomaly warning (including a status display and a warning) for the secondary battery. If the neural network unit 106 determines that an anomaly is detected, the system may forcibly shut down the power.

[0060] Furthermore, although the present embodiment has been described with respect to a vehicle operated by a driver, this is not particularly limited, and by combining a camera or radar that captures images of the area around the vehicle with an ECU that performs image processing, the present invention can also be applied to a vehicle that can perform semi-automatic driving or fully automatic driving.

[0061] Furthermore, the present embodiment is not limited to applications to vehicles operated by a driver, but can also be applied to home power storage devices.

[0062] (Embodiment 2) In this embodiment, an example of a laminated secondary battery is shown in Figures 2A and 2B. Figure 2A is an external view, and Figure 2B is a cross-sectional view taken along chain line AB in Figure 2A.

[0063] The secondary battery 500 includes a positive electrode 503 , a negative electrode 506 , a separator 507 , an outer casing 509 , a positive electrode lead electrode 510 , and a negative electrode lead electrode 511 .

[0064] The laminated secondary battery 500 is fabricated as follows.

[0065] First, a positive electrode 503, a negative electrode 506, and a separator 507 are prepared. A positive electrode active material layer 502 is provided on a positive electrode current collector. The positive electrode 503 preferably has a tab region where the positive electrode current collector is exposed. The negative electrode 506 has a negative electrode active material layer 505 on a negative electrode current collector. The negative electrode 506 preferably has a tab region where the negative electrode current collector is exposed.

[0066] Next, separator 507 is placed on positive electrode 503 so as to overlap the entire surface of positive electrode 503. Thereafter, a laminate of positive electrode 503, separator 507, and negative electrode 506 is further laminated to produce laminate 512 shown in FIG. 2B.

[0067] Next, the positive electrode 503, the separator 507, and the negative electrode 506 are sealed with the exterior body 509a and the exterior body 509b. The exterior bodies 509a and 509b are sealed in a region 514 by thermocompression bonding. Before sealing, the nonaqueous electrolyte 513 is poured into the region surrounded by the exterior body 509a and the exterior body 509b. Alternatively, the nonaqueous electrolyte 513 may be degassed before sealing. Furthermore, although FIG. 2B schematically illustrates gaps in which the nonaqueous electrolyte 513 exists, in reality the region is sealed with almost no gaps.

[0068] 2A, exterior bodies 509a and 509b are shown as exterior body 509. As shown in FIG. 2A, one laminate film is folded over and sealed on three sides (sometimes called three-sided sealing), but this is not particularly limited, and two laminate films may be used to seal exterior bodies 509a and 509b on all four sides (sometimes called four-sided sealing).

[0069] After sealing, a spray gun is used to spray temperature-sensitive paint onto part of the surface of exterior body 509a, providing temperature-sensitive paint layer 520. It is desirable that temperature-sensitive paint layer 520 be formed to a uniform thickness.

[0070] Because the laminated film of the laminated secondary battery 500 is thin, the surface temperature of the exterior body is more likely to change when heat is generated than in a metal can exterior body. Therefore, it is easy to detect abnormalities by using an imaging device to capture the light emitted from the temperature-sensitive paint layer 520 as image data. Furthermore, the laminated secondary battery 500 can be made large, and even in such cases, it is possible to detect heat generation due to local short circuits, which are difficult to measure with an internal temperature sensor.

[0071] 2B, the thickness of the laminate film is shown as thin, but in reality, the thickness of the laminate film is approximately 100 μm, and the thickness of the temperature-sensitive paint layer 520 is 100 nm or more and 10 μm or less. In this embodiment, a ruthenium complex is used as the temperature-sensitive paint layer 520, and polyacrylic acid is used as the binder, with a thickness of 1 μm. Image data of the light emitted from the temperature-sensitive paint layer 520 can be obtained using a high-speed visible light CCD camera.

[0072] The laminate film is a sheet made of a flexible substrate, and the sheet uses a laminate having an adhesive layer (also called a heat seal layer) on one or both sides of a metal film. The adhesive layer uses a heat-sealable resin film containing polypropylene or polyethylene. In this embodiment, the sheet is a metal sheet (also called a laminate film) having nylon resin on the surface of an aluminum foil and an acid-resistant polypropylene film and a polypropylene film laminate on the back of the aluminum foil.

[0073] The thickness of the separator 507 is about 15 μm or more and 30 μm or less, the thickness of the current collector of the positive electrode 503 is about 10 μm or more and 40 μm or less, the thickness of the positive electrode active material layer 502 is about 50 μm or more and 100 μm or less, the thickness of the negative electrode active material layer 505 is about 50 μm or more and 100 μm or less, and the thickness of the current collector of the negative electrode 506 is about 5 μm or more and 40 μm or less.

[0074] (Embodiment 3) While an example of a laminated secondary battery was shown in Embodiment 2, an example of a cylindrical secondary battery will be described in this embodiment with reference to Fig. 3A. As shown in Fig. 3A, cylindrical secondary battery 616 has a positive electrode cap (battery lid) 601 on the top surface and a battery can (external can) 602 on the side and bottom surfaces. Positive electrode cap 601 and battery can (external can) 602 are insulated by gasket (insulating packing) 610.

[0075] Fig. 3B is a diagram showing a schematic cross section of a cylindrical secondary battery. The cylindrical secondary battery shown in Fig. 3B has a positive electrode cap (battery lid) 601 on the top surface and a battery can (external can) 602 on the side and bottom surfaces. The positive electrode cap and battery can (external can) 602 are insulated by a gasket (insulating packing) 610.

[0076] A battery element is provided inside a hollow cylindrical battery can 602, in which a strip-shaped positive electrode 604 and a negative electrode 606 are wound with a separator 605 sandwiched between them. Although not shown, the battery element is wound around a central axis. One end of the battery can 602 is closed and the other end is open. The battery can 602 can be made of metals such as nickel, aluminum, or titanium, or alloys of these metals or alloys of these metals with other metals (e.g., stainless steel), which are corrosion-resistant to the electrolyte. Furthermore, it is preferable to coat the battery can 602 with nickel or aluminum to prevent corrosion by the electrolyte. Inside the battery can 602, the wound battery element, in which the positive electrode, negative electrode, and separator are wound, is sandwiched between a pair of opposing insulating plates 608 and 609. Furthermore, a nonaqueous electrolyte (not shown) is poured into the interior of the battery can 602 containing the battery element.

[0077] Since the positive and negative electrodes used in cylindrical secondary batteries are wound, it is preferable to form active materials on both sides of the current collector.

[0078] A positive electrode terminal (positive electrode current collector lead) 603 is connected to the positive electrode 604, and a negative electrode terminal (negative electrode current collector lead) 607 is connected to the negative electrode 606. Both the positive electrode terminal 603 and the negative electrode terminal 607 can be made of aluminum. The positive electrode terminal 603 is resistance-welded to a safety valve mechanism 613, and the negative electrode terminal 607 is resistance-welded to the bottom of the battery can 602. The safety valve mechanism 613 is electrically connected to the positive electrode cap 601 via a PTC (Positive Temperature Coefficient) element 611. The safety valve mechanism 613 cuts off the electrical connection between the positive electrode cap 601 and the positive electrode 604 when the internal pressure of the battery exceeds a predetermined threshold. The PTC element 611 is a thermosensitive resistor whose resistance increases with increasing temperature. This increased resistance limits the amount of current and prevents abnormal heat generation. The PTC element can be made of barium titanate (BaTiO3)-based semiconductor ceramics.

[0079] 3C shows an example of a power storage system 615. The power storage system 615 has a plurality of secondary batteries 616. The positive electrodes of the secondary batteries are in contact with and electrically connected to conductors 624 separated by insulators 625.

[0080] A temperature-sensitive paint layer is applied to the side (curved surface) of the battery can 602, and the heat generation state is monitored by an imaging device that captures images from the side direction, thereby forming a monitoring system.

[0081] Alternatively, a monitoring system may be configured in which a temperature-sensitive paint layer is applied to an insulator 625 provided near the battery can 602, and the heat generation is monitored from above with an imaging device. In this case, a temperature-sensitive paint layer can be applied to the surface of an object, and the temperature change of the battery can 602 can be monitored with an imaging device through the object (insulator 625). In this way, a temperature-sensitive paint layer can be applied to an exterior body via the object, and indirect monitoring can be performed with an imaging device. However, there are cases in which the object can be considered part of the exterior body. The object is not limited to an insulator. A temperature-sensitive paint layer can be applied to a conductive plate connecting multiple batteries, and the temperature change of the battery can 602 can be monitored with an imaging device through the conductive plate. However, this makes it difficult to determine which secondary battery is abnormal, and accuracy may be reduced.

[0082] The conductor 624 is electrically connected to the control circuit 620 via a wiring 623. The negative electrode of each secondary battery is electrically connected to the control circuit 620 via a wiring 626. The control circuit 620 can be a charge / discharge control circuit that performs charging / discharging or a protection circuit that prevents overcharging or overdischarging.

[0083] This embodiment mode can be freely combined with other embodiment modes.

[0084] (Fourth embodiment) Although an example of a cylindrical secondary battery has been shown in the third embodiment, an example of a rectangular secondary battery will be described in this embodiment with reference to FIGS.

[0085] A secondary battery 913 shown in FIG. 4A has a wound body 950 provided with terminals 951 and 952 inside a housing 930. The wound body 950 is immersed in an electrolyte inside the housing 930. The terminal 952 contacts the housing 930, and the terminal 951 is not in contact with the housing 930 due to the use of an insulating material. Note that in FIG. 4A, for convenience, the housing 930 is shown separated, but in reality, the wound body 950 is covered by the housing 930, and the terminals 951 and 952 extend outside the housing 930. The housing 930 can be made of a metal material (e.g., aluminum) or a resin material.

[0086] 4B, the housing 930 shown in Fig. 4A may be formed from a plurality of materials. For example, the secondary battery 913 shown in Fig. 4B has housings 930a and 930b bonded together, and a wound body 950 is provided in the area surrounded by the housings 930a and 930b.

[0087] The housing 930a can be made of organic resin or an insulating material. In particular, by using an organic resin material on the surface on which the antenna is formed, it is possible to prevent the secondary battery 913 from blocking the electric field. Note that if the electric field blocking by the housing 930a is small, the antenna may be provided inside the housing 930a. The housing 930b can be made of, for example, a metal material.

[0088] Furthermore, since the housing 930b corresponds to an exterior body, by applying a temperature-sensitive paint layer to part of the surface of the housing 930b, it is possible to capture images of heat generation using an imaging device.

[0089] 4C shows the structure of wound body 950. Winding body 950 has a negative electrode 931, a positive electrode 932, and a separator 933. Winding body 950 is a wound body in which negative electrode 931 and positive electrode 932 are stacked on top of each other with separator 933 sandwiched therebetween, and the resulting laminated sheet is wound. Note that multiple stacks of negative electrode 931, positive electrode 932, and separator 933 may be stacked.

[0090] Alternatively, a secondary battery 913 may be provided having a wound body 950a as shown in Fig. 5. The wound body 950a shown in Fig. 5A has a negative electrode 931, a positive electrode 932, and a separator 933. The negative electrode 931 has a negative electrode active material layer 931a. The positive electrode 932 has a positive electrode active material layer 932a.

[0091] The separator 933 has a width wider than the negative electrode active material layer 931a and the positive electrode active material layer 932a, and is wound so as to overlap the negative electrode active material layer 931a and the positive electrode active material layer 932a. From the standpoint of safety, it is preferable that the negative electrode active material layer 931a be wider than the positive electrode active material layer 932a. A wound body 950a having such a shape is preferable because of its high safety and productivity.

[0092] 5B, negative electrode 931 is electrically connected to terminal 951 by ultrasonic bonding, welding, or crimping. Terminal 951 is electrically connected to terminal 911a. Positive electrode 932 is electrically connected to terminal 952 by ultrasonic bonding, welding, or crimping. Terminal 952 is electrically connected to terminal 911b.

[0093] 5C, wound body 950a and the electrolyte are covered by casing 930 to form secondary battery 913. It is preferable to provide a safety valve and an overcurrent protection element in casing 930. The safety valve is a valve that opens when the inside of casing 930 reaches a predetermined internal pressure to prevent the battery from exploding.

[0094] As shown in Fig. 5B, the secondary battery 913 may have multiple wound bodies 950a. Using multiple wound bodies 950a can result in a secondary battery 913 with a larger charge / discharge capacity. For other elements of the secondary battery 913 shown in Figs. 5A and 5B, the descriptions of the secondary battery 913 shown in Figs. 4A to 4C can be referred to.

[0095] Furthermore, since the housing 930 corresponds to an exterior body, by applying a temperature-sensitive paint layer to part of the surface of the housing 930, it is possible to capture images of heat generation using an imaging device.

[0096] Furthermore, a temperature-sensitive paint layer may be applied to the upper surface of terminal 951 where terminal 911a is provided (the upper surface of secondary battery 913). Note that it is preferable that terminal 951 is not provided in contact with terminal 911a so as not to interfere with electrical connection. If secondary batteries 913 are arranged closely together, their sides may come into contact with each other, making it difficult to measure with an imaging device; however, if a temperature-sensitive paint layer is applied to the upper surface of secondary battery 913, it becomes possible for the imaging device to detect abnormalities.

[0097] This embodiment mode can be freely combined with other embodiment modes.

[0098] (Embodiment 5) In this embodiment, an example of a flow for monitoring abnormal heat generation in a secondary battery using the monitoring system shown in Embodiment 1 is shown in FIG.

[0099] Data is acquired before starting the motor of the electric vehicle equipped with the monitoring system according to the first embodiment.

[0100] Preparation for acquiring data for predicting abnormal heat generation in the secondary battery begins (S11).

[0101] A light source installed near the secondary battery is turned on, and an image of the secondary battery's exterior is captured (S13). The secondary battery is coated with a temperature-sensitive paint layer. When irradiated with light from the light source, the temperature-sensitive paint layer emits light in areas overlapping with the abnormal heat source. This light emission is captured as image data using a CCD or image sensor imaging device. The driver can visually check the display for any abnormalities in the secondary battery before starting the motor. CCD imaging devices are less expensive than thermographic cameras. Detecting the emission of light from the temperature-sensitive paint layer has the advantage of being able to detect an abnormality over a wide range in an instant, making it useful. Furthermore, using individual thermometers only captures data within a narrow temperature range, making it difficult to detect a wide temperature range. In a configuration using 1,000 or more secondary batteries, the same number of thermometers would be required, which would be expensive. The monitoring system described in embodiment 1 can handle even large secondary batteries or 5,000 secondary batteries by providing one or more imaging devices and detecting the emission of light from the temperature-sensitive paint layer.

[0102] If the obtained image data does not reveal any abnormal heat generation and the vehicle is determined to be normal, the driver starts the motor of the electric vehicle using the secondary battery.

[0103] Next, the electrical characteristics of the secondary battery, such as voltage, current, and internal temperature, are measured (S14), thereby obtaining electrical characteristic data.

[0104] The acquired image data and electrical characteristic data are stored in a database (S12).

[0105] The electric vehicle begins operation, and image data and electrical characteristic data are stored in a database, either periodically or repeatedly at irregular intervals.

[0106] When data for creating or updating the learning model is obtained, the learning model is updated (S15).To build a model using an ensemble learning algorithm, the prepared dataset is divided into training data and test data, and a predictive model is created and evaluated.

[0107] The database may be prepared with learning data in advance. For example, past data collected during the previous trip or learning data previously acquired by the manufacturer of the electric vehicle may be acquired. These data are stored in the database in advance. The database may also be updated as needed directly or indirectly via wireless communication from an external device (external server).

[0108] Once the learning model update is complete, operation resumes. In this embodiment, steps S11 to S15 can be considered the first stage for learning.

[0109] The second step for estimation is then shown below.

[0110] Using the learning model, neural network processing is performed based on the image data or electrical characteristic data, and an estimated value is output (S21).

[0111] And the third stage for anomaly detection is shown below.

[0112] The current estimated value is compared with the previous estimated value to make a judgment (S22). The difference (absolute value) between the previous estimated value and the current estimated value is used as the standard for judging an abnormality. The magnitude of the difference that is deemed to be an abnormality is stored in the lookup data, corresponding to the temperature.

[0113] If the difference, that is, the fluctuation in the estimated value, is large compared with the lookup data, it is determined that an abnormality has occurred, and an abnormality detection warning is displayed to the driver of the vehicle (S23).

[0114] Furthermore, if the difference, that is, the fluctuation in the estimated value, is small compared to the lookup data, it is determined to be normal.

[0115] By repeating the above steps 1, 2, and 3 while driving, the learning model can be updated while detecting anomalies, allowing the vehicle to continue driving safely.In addition, by using a relatively small amount of data (short periods of data before and after stopping) instead of using a huge amount of data while driving, the memory capacity and amount of calculation can be reduced, and highly accurate estimation and anomaly detection can be performed.

[0116] According to this embodiment, the driver can not only visually check the appearance of the secondary battery at will when he or she is concerned while driving, but also safely drive while highly accurate abnormality detection is performed by neural network processing.

[0117] In this embodiment, it is possible to improve safety by checking for abnormalities in both image data and electrical characteristic data in real time.

[0118] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0119] (Sixth embodiment) In this embodiment, an example in which a secondary battery monitoring system according to one embodiment of the present invention is mounted on a vehicle, typically a transportation vehicle, and a secondary battery monitoring system installed in a building will be described.

[0120] Installing the secondary battery shown in any one of FIGS. 2A, 3A, 5A, 4B, and 5C in a vehicle can realize a next-generation clean energy vehicle, such as a hybrid vehicle (HV), an electric vehicle (EV), or a plug-in hybrid vehicle (PHV). The secondary battery can also be installed in agricultural machinery, motorized bicycles including electrically assisted bicycles, motorcycles, electric wheelchairs, electric carts, small or large ships, submarines, fixed-wing or rotary-wing aircraft, rockets, satellites, space probes or planetary probes, and transportation vehicles such as spacecraft. The monitoring system of one embodiment of the present invention allows remote external abnormality checks because a temperature-sensitive paint layer applied to the exterior of the secondary battery emits light. Therefore, the secondary battery of one embodiment of the present invention is suitable for use in transportation vehicles.

[0121] 7A to 7E illustrate examples of transportation vehicles using one embodiment of the present invention. The automobile 2001 shown in FIG. 7A is an electric automobile using an electric motor as a power source for traveling. Alternatively, it is a hybrid automobile that can selectively use an electric motor or an engine as a power source for traveling. When a secondary battery using one embodiment of the present invention is installed in a vehicle, a temperature-sensitive paint layer applied to the exterior of the secondary battery emits light, allowing for remote external abnormality checks. The automobile 2001 shown in FIG. 7A includes a battery pack 1301a, which includes a secondary battery module to which multiple secondary batteries are connected. It is preferable that the battery pack 1301a further includes a charge control device electrically connected to the secondary battery module. The secondary battery of the electric vehicle includes a service plug or circuit breaker that can cut off high voltage without using tools to cut off power from the multiple secondary batteries. For example, when 48 battery modules, each having 2 to 10 cells, are connected in series, a service plug or circuit breaker is provided between the 24th and 25th batteries. When an anomaly detection system using one embodiment of the present invention is installed in an automobile 2001, neural network processing can be performed to detect an anomaly in the secondary battery. Therefore, if the neural network determines that a danger exists, the system may be used as a danger avoidance system that shuts off the power supply by activating a service plug or circuit breaker. In addition to the anomaly detection system using one embodiment of the present invention, an environment recognition unit, such as a stereo camera, sonar, a multifocal multi-lens camera system, LIDAR, millimeter-wave radar, or an infrared sensor (TOF method), may also be combined to construct a driving assistance system. Since the driving assistance system also uses a neural network for image recognition, a common program and IC chip can be used for part of the calculation processing between the anomaly detection system using one embodiment of the present invention and the driving assistance system, thereby reducing costs and the number of parts. The TOF distance measurement system is composed of a light source and a photodetector (sensor or camera). The camera used in this TOF method is called a time-of-flight camera, also known as a TOF camera.A TOF camera can obtain distance information from a light source to an object based on the time of flight of the light reflected from the object.

[0122] Furthermore, the automobile 2001 can charge its battery pack 1301a by receiving power from an external charging facility via a plug-in system or a wireless power supply system. The charging method or connector standard may be a predetermined system, such as CHAdeMO (registered trademark) or Combo, as appropriate. The charging facility for the secondary battery may be a charging station installed in a commercial facility or a household power source. For example, plug-in technology can be used to charge the battery pack 1301a installed in the automobile 2001 using external power supply. Charging can be performed by converting AC power to DC power via an AC-DC converter. While charging the battery pack 1301a of the automobile 2001, the driver may leave the vehicle until charging is complete. In this case, neural network processing is used to monitor abnormalities during charging, and charging can be stopped if the neural network determines that there is a danger. Therefore, this embodiment allows the driver to leave the vehicle safely until charging is complete.

[0123] Also, although not shown, a power receiving device can be mounted on a vehicle, and power can be supplied contactlessly from a ground power transmitting device to charge the battery pack 1301a. In the case of this contactless power supply method, by incorporating a power transmitting device into a road or an exterior wall, charging can be performed not only while the vehicle is stopped but also while it is moving. This contactless power supply method can also be used to transmit and receive power between two vehicles. Furthermore, solar cells can be installed on the exterior of the vehicle, and the secondary battery can be charged while the vehicle is stopped or moving. For such contactless power supply, an electromagnetic induction method or a magnetic field resonance method can be used.

[0124] 7B shows a large transport vehicle 2002 having an electrically controlled motor as an example of a transport vehicle. The secondary battery module of the transport vehicle 2002 is, for example, a four-cell unit of secondary batteries with a nominal voltage of 3.0 V to 5.0 V, with 48 cells connected in series for a maximum voltage of 170 V. Apart from the number of secondary batteries constituting the secondary battery module of the battery pack 2201, the same functions as those in FIG. 7A are provided, and therefore a description thereof will be omitted.

[0125] FIG. 7C shows, as an example, a large transport vehicle 2003 having an electrically controlled motor. The secondary battery module of the transport vehicle 2003 has, for example, a maximum voltage of 600 V, with more than 100 secondary batteries connected in series, each having a nominal voltage of 3.0 V or more and 5.0 V or less. Therefore, it is necessary to monitor many secondary batteries, and safety is required. Therefore, the monitoring system shown in the first embodiment is useful because it can improve safety. Furthermore, except for the number of secondary batteries constituting the secondary battery module of the battery pack 2202, the system has the same functions as those in FIG. 7A, and therefore a description thereof will be omitted.

[0126] 7D shows, as an example, an aircraft 2004 having an engine that burns fuel. Since the aircraft 2004 shown in Fig. 7D has wheels for takeoff and landing, it can also be said to be part of a transportation vehicle, and has a battery pack 2203 that includes a secondary battery module formed by connecting multiple secondary batteries and includes the secondary battery module and a charge control device.

[0127] The secondary battery module of the aircraft 2004 has, for example, eight 4V secondary batteries connected in series, resulting in a maximum voltage of 32V. The secondary battery module of the aircraft 2004 needs to be monitored, and safety is required. Therefore, the monitoring system described in the first embodiment is useful because it can improve safety. The monitoring system described in the first embodiment can also identify the location of an abnormal secondary battery. Therefore, image data of the secondary battery can be sent to the control tower and emergency replacement can be performed during flight while communicating with the control tower. Other than the number of secondary batteries constituting the secondary battery module of the battery pack 2203, the system has the same functions as those shown in FIG. 7A, and therefore a description thereof will be omitted. The aircraft 2004 is equipped with a storage device called a black box, which includes two devices: a flight data recorder and a cockpit voice recorder. This recording device may also be used as a system for automatically recording image data for monitoring the secondary batteries. In the event of an accident, it may be possible to determine later whether an abnormality in the secondary battery was the cause. In the past, when a secondary battery exploded, no evidence was left behind, making it difficult to determine the cause.

[0128] FIG. 7E shows an example of a transport vehicle 2005 for transporting cargo. It has an electrically controlled motor and performs various tasks by receiving power from a secondary battery constituting a secondary battery module of a battery pack 2204. Furthermore, the transport vehicle 2005 does not necessarily have to be operated by a human driver, but can also be unmanned via CAN communication. While FIG. 7E illustrates a forklift, this is not a limitation, and the secondary battery monitoring system according to one embodiment of the present invention can be mounted on industrial machinery that can be operated via CAN communication, such as an automated transporter, a work robot, or a small construction machine.

[0129] [Buildings] Next, an example in which the secondary battery of one embodiment of the present invention is mounted in a building will be described with reference to FIG.

[0130] 8A includes a safe power storage device 2612 and a solar panel 2610 using the secondary battery monitoring system according to one embodiment of the present invention. The power storage device 2612 is electrically connected to the solar panel 2610 through a wiring 2611. The power storage device 2612 may also be electrically connected to a ground-mounted charging device 2604. The power obtained by the solar panel 2610 can be charged to the power storage device 2612. The power stored in the power storage device 2612 can be charged to a secondary battery included in the vehicle 2603 via the charging device 2604. The power storage device 2612 is preferably installed in an underfloor space. By installing the power storage device 2612 in the underfloor space, the space above the floor can be effectively utilized. Alternatively, the power storage device 2612 may be installed on the floor.

[0131] The power stored in the power storage device 2612 can be supplied to other electronic devices in the house. Therefore, even when power cannot be supplied from the commercial power source due to a power outage, the power storage device 2612 can be used as an uninterruptible power supply, allowing the use of electronic devices.

[0132] FIG. 8B illustrates an example of a power storage device 700 according to one embodiment of the present invention. As shown in FIG. 8B, a large-scale power storage device 791 including a secondary battery monitoring system according to one embodiment of the present invention is installed in an underfloor space 796 of a building 799. The underfloor space 796 is made into a closed space, and a light source and an imaging device are installed therein. This enables abnormality detection based on the light emission from a temperature-sensitive paint layer applied to the secondary battery. If abnormal heat generation occurs, image data can be sent to the manufacturer, allowing appropriate countermeasures to be taken.

[0133] A control device 790 is installed in the power storage device 791, and the control device 790 is electrically connected to a distribution board 703, a power storage controller 705 (also called a control device), a display 706, and a router 709 by wiring.

[0134] Electric power is sent from commercial power source 701 to distribution board 703 via service line attachment section 710. Electric power is also sent to distribution board 703 from power storage device 791 and commercial power source 701, and distribution board 703 supplies the sent electric power to general load 707 and power storage load 708 via an outlet (not shown).

[0135] The general load 707 is, for example, an electrical appliance such as a television or a personal computer, and the power storage load 708 is, for example, an electrical appliance such as a microwave oven, a refrigerator, or an air conditioner.

[0136] The power storage controller 705 has a measurement unit 711, a prediction unit 712, and a planning unit 713. The measurement unit 711 has a function of measuring the amount of power consumed by the general load 707 and the power storage load 708 during one day (for example, from midnight to midnight). The measurement unit 711 may also have a function of measuring the amount of power of the power storage device 791 and the amount of power supplied from the commercial power source 701. The prediction unit 712 has a function of predicting the amount of power demand to be consumed by the general load 707 and the power storage load 708 during the next day, based on the amount of power consumed by the general load 707 and the power storage load 708 during the previous day. The planning unit 713 has a function of creating a plan for charging and discharging the power storage device 791, based on the amount of power demand predicted by the prediction unit 712.

[0137] The amount of power consumed by the general load 707 and the power storage load 708 measured by the measurement unit 711 can be confirmed on the display 706. It can also be confirmed on an electrical device such as a television or a personal computer via the router 709. It can also be confirmed on a mobile electronic device such as a smartphone or a tablet via the router 709. The amount of power demand for each time period (or each hour) predicted by the prediction unit 712 can also be confirmed on the display 706, the electrical device, and the mobile electronic device.

[0138] If the power storage controller 705 is configured to be capable of performing neural network processing, it is also possible to estimate abnormal heat generation in the secondary battery by utilizing a temperature-sensitive paint layer applied to the secondary battery.

[0139] This embodiment mode can be implemented in appropriate combination with other embodiment modes. [Explanation of symbols]

[0140] 101: Secondary battery, 102: Charging control circuit, 103: Ammeter, 104: Voltmeter, 105: Internal temperature sensor, 106: Neural network unit, 107: Determination unit, 108: Memory unit, 109: Display unit, 111: Imaging device, 112: Temperature adjustment mechanism, 113: Light source, 150: Monitoring system, 500: Secondary battery, 501: Positive electrode current collector, 502: Positive electrode active material layer, 503: Positive electrode, 504: Negative electrode current collector, 505: Negative electrode active material layer, 506: Negative electrode, 507: Separator, 509: Exterior body, 509a: Exterior body, 50 9b: exterior body, 510: positive electrode lead electrode, 511: negative electrode lead electrode, 512: laminate, 513: non-aqueous electrolyte, 514: region, 520: temperature-sensitive paint layer, 601: positive electrode cap, 602: battery can, 603: positive electrode terminal, 604: positive electrode, 605: separator, 606: negative electrode, 607: negative electrode terminal, 608: insulating plate, 609: insulating plate, 611: PTC element, 613: safety valve mechanism, 615: power storage system, 616: secondary battery, 620: control circuit, 623: wiring, 624: conductor, 625: insulator, 626: wiring, 700: Energy storage device, 701: Commercial power source, 703: Distribution board, 705: Energy storage controller, 706: Display, 707: General load, 708: Energy storage load, 709: Router, 710: Lead wire attachment section, 711: Measurement section, 712: Prediction section, 713: Planning section, 790: Control device, 791: Energy storage device, 796: Underfloor space section, 799: Building, 911a: Terminal, 911b: Terminal, 913: Secondary battery, 930: Housing, 930a: Housing, 930b: Housing, 931: Negative electrode, 931a: Negative electrode active material layer, 932: Positive electrode, 932 a: positive electrode active material layer, 933: separator, 950: wound body, 950a: wound body, 951: terminal, 952: terminal, 1010: secondary battery, 1301a: battery pack, 2001: automobile, 2002: transport vehicle, 2003: transport vehicle, 2004: aircraft, 2005: transport vehicle, 2200: battery pack, 2201: battery pack, 2202: battery pack, 2203: battery pack, 2204: battery pack, 2603: vehicle, 2604: charging device, 2610: solar panel, 2611: wiring, 2612: power storage device

Claims

[Claim 1] A secondary battery having a positive electrode, a negative electrode, and an outer casing, the outer casing enclosing at least a portion of the positive electrode and the negative electrode; The secondary battery has a temperature-sensitive paint on the surface of the exterior body.

Images