power storage unit

Abstract

The present application relates to an electric storage unit. The electric storage unit includes an outer body (90), a main body portion (50), and a detection unit (500). The main body portion (50) is disposed inside the outer body (90). At least a portion of the detection unit (500) is disposed inside the outer body (90), and the detection unit (500) detects a state of the electric storage unit (100) and performs wireless communication.

Description

Technical Field

[0001] This technology relates to energy storage units. Background Technology

[0002] Japanese Patent Application Publication No. 2020-27767 discloses the structure of a battery monitoring device. The battery monitoring device described in Japanese Patent Application Publication No. 2020-27767 includes a detection board mounted on a battery module. The detection board includes: a detection circuit for detecting the status information of the battery module, a wireless circuit, and an antenna for wirelessly transmitting the status information of the battery module.

[0003] In the battery monitoring device described in Japanese Patent Application Publication No. 2020-27767, the space occupied is increased because a detection board is mounted on the battery module. Furthermore, the space occupied is also increased because space is needed to accommodate a power supply for powering the detection board. Summary of the Invention

[0004] The purpose of this technology is to provide an energy storage unit that suppresses the enlargement of its occupied space and has a detection unit for wireless communication.

[0005] The first aspect of this technology relates to a power storage unit comprising an outer casing, a main body, and a detection unit. The main body is disposed inside the outer casing. At least a portion of the detection unit is disposed inside the outer casing, and the detection unit detects the state of the power storage unit and performs wireless communication.

[0006] The second aspect of this technology relates to a power storage unit comprising a main body, a current collector, and a detection unit. The current collector is connected to the main body. The detection unit is electrically connected to the current collector and is powered thereon, detecting the state of the power storage unit and performing wireless communication.

[0007] The above and other objects, features, aspects and advantages of the present invention will become clear from the following detailed description relating to the invention, which will be understood in conjunction with the accompanying drawings. Attached Figure Description

[0008] Figure 1 This is a diagram showing the basic structure of a battery pack.

[0009] Figure 2 This is a diagram showing the battery cells and end plates contained in a battery pack.

[0010] Figure 3 This is a diagram showing the battery cells in a battery pack.

[0011] Figure 4 From Figure 3 A cross-sectional view viewed in the direction of the arrow along line IV-IV.

[0012] Figure 5 This is a schematic diagram illustrating an example of the structure of the electrode body in this embodiment.

[0013] Figure 6 This is a circuit diagram showing the electrical connection between the battery cell and the detection unit.

[0014] Figure 7 This is a functional block diagram representing a specific instance of a detection unit.

[0015] Figure 8 This is a partial cross-sectional view of the periphery of the antenna section of the battery cell in the first modified embodiment 1.

[0016] Figure 9 This is an exploded perspective view showing the structure of the detection unit and the outer casing of the battery cell in the second variation of Embodiment 1.

[0017] Figure 10 This is a partial cross-sectional view showing the structure of the detection unit of the battery cell in the second variation of Embodiment 1.

[0018] Figure 11 This is a top view showing the appearance of the battery cell in Embodiment 2.

[0019] Figure 12 This is an exploded perspective view showing the structure of the battery cell in Embodiment 2.

[0020] Figure 13 This is a top view showing the appearance of the battery cell in a modified example of Embodiment 2. Detailed Implementation

[0021] The following describes the implementation of this technology. It should be noted that the same or equivalent parts are labeled with the same reference numerals, and sometimes the description is not repeated.

[0022] It should be noted that, in the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of this technology is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. Furthermore, in the embodiments described below, each constituent element is not necessarily essential to this technology, unless specifically stated otherwise.

[0023] It should be noted that in this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a structure is included, other structures besides that structure may be included, or they may not be included. Furthermore, this technology is not limited to technologies that must achieve all the effects mentioned in this embodiment.

[0024] In this specification, "battery" is not limited to lithium-ion batteries and may include other batteries such as nickel-metal hydride batteries. In this specification, "electrode" can be collectively referred to as the positive electrode and the negative electrode. Additionally, "electrode plate" can be collectively referred to as the positive electrode plate and the negative electrode plate. "Current collector" can be collectively referred to as the positive electrode current collector and the negative electrode current collector.

[0025] In this specification, "energy storage unit" or "energy storage module" is not limited to battery unit or battery module, but may include capacitor unit or capacitor module.

[0026] (Implementation Method 1)

[0027] Figure 1 This is a diagram showing the basic structure of battery pack 1. Figure 2 This is a diagram showing the battery cells 100 and end plate 200 included in battery pack 1.

[0028] like Figure 1 , Figure 2 As shown, the battery pack 1, which is an example of an "energy storage module", includes a battery cell 100, an end plate 200, a restraint component 300, and a resin plate 400.

[0029] Multiple battery cells 100 are arranged in a manner along the Y-axis direction (arrangement direction). This forms a stack of battery cells 100. A separator (not shown) is sandwiched between the multiple battery cells 100. The multiple battery cells 100, held by two end plates 200, are pressed by the end plates 200 and constrained between the two end plates 200.

[0030] End plates 200 are disposed at both ends of the battery pack 1 in the Y-axis direction. The end plates 200 are fixed to a base such as a housing that houses the battery pack 1. Stepped portions 210 are formed at both ends of the end plates 200 in the X-axis direction (width direction).

[0031] The constraint member 300 connects the two end plates 200 to each other. The constraint member 300 is mounted on the stepped portions 210 formed on the two end plates 200 respectively.

[0032] While a compressive force in the Y-axis direction is applied to the stack of multiple battery cells 100 and end plates 200, the constraint member 300 is engaged with the end plate 200. After the compressive force is released, a tensile force is applied to the constraint member 300 connecting the two end plates 200. In response, the constraint member 300 presses the two end plates 200 toward each other.

[0033] The constraint component 300 includes a first component 310 and a second component 320. The first component 310 and the second component 320 are joined together, for example, by butt welding. The front end face of the second component 320, formed by being folded back, abuts against the stepped portion 210 of the end plate 200 in the Y-axis direction.

[0034] Figure 3 This is a diagram showing the battery cell 100 in battery pack 1. Figure 4 From Figure 3 A cross-sectional view viewed in the direction of the arrow along line IV-IV. (See example.) Figure 3 as well as Figure 4 As shown, the battery cell 100 includes an outer casing 90, an electrode body 50, a positive terminal 81, a negative terminal 82, a positive current collector 71, and a negative current collector 72.

[0035] The outer casing 90 is square (flat cuboid shape). However, square is just one example. The outer casing 90 can have any shape. The outer casing 90 can be, for example, cylindrical or bag-shaped. The outer casing 90 can be, for example, made of Al alloy. The outer casing 90 houses the electrode body 50 and electrolyte (not shown). The outer casing 90 can, for example, include a sealing plate 91 and an outer container 92. The outer container 92 has an opening. The sealing plate 91 seals the opening of the outer container 92. For example, the sealing plate 91 can be joined to the outer container 92 by laser welding.

[0036] A positive terminal 81 and a negative terminal 82 are provided on the sealing plate 91. The positive terminal 81 is fixed to the sealing plate 91 through a resin insulating component 61. The negative terminal 82 is fixed to the sealing plate 91 through a resin insulating component 62.

[0037] The positive terminal 81 is preferably made of metal, more preferably of aluminum or an aluminum alloy. The negative terminal 82 is preferably made of metal, more preferably of copper or a copper alloy. The negative terminal 82 may be configured to have a region made of copper or a copper alloy disposed on the inner side of the outer casing 90 and a region made of aluminum or an aluminum alloy disposed on the outer side of the outer casing 90.

[0038] An injection port 41 and a gas discharge valve 42 may also be provided on the sealing plate 91. Electrolyte can be injected into the interior of the outer casing 90 through the injection port 41. The gas discharge valve 42 breaks when the pressure inside the outer casing 90 exceeds a threshold value. As a result, flammable gas inside the outer casing 90 is discharged to the outside of the outer casing 90. A current collector is connected to the electrode body 50. Specifically, the electrode body 50 is connected to the positive terminal 81 via a positive current collector 71. The positive current collector 71 may be, for example, an Al plate. The electrode body 50 is connected to the negative terminal 82 via a negative current collector 72. The negative current collector 72 may be, for example, a Cu plate.

[0039] Figure 5This is a schematic diagram illustrating an example of the structure of the electrode body in this embodiment. The electrode body 50, which forms the main body of the battery cell 100, is disposed inside the outer casing 90. The electrode body 50 is a wound type. The electrode body 50 includes a positive electrode 10, a separator 30, and a negative electrode 20. That is, the battery cell 100 includes a positive electrode 10, a negative electrode 20, and an electrolyte. The positive electrode 10, the separator 30, and the negative electrode 20 are all strip-shaped sheets. The electrode body 50 may also include multiple separators 30. The electrode body 50 is formed by sequentially stacking the positive electrode 10, the separator 30, and the negative electrode 20 and winding them in a spiral shape. Either the positive electrode 10 or the negative electrode 20 may be held by the separator 30. Both the positive electrode 10 and the negative electrode 20 may be held by the separator 30. The electrode body 50 may also be formed into a flat shape after winding. It should be noted that the wound type is one example. The electrode body 50 may also be a stacked type, for example.

[0040] The positive electrode 10 includes a positive electrode substrate 11 and a positive electrode active material layer 12. The positive electrode substrate 11 is a conductive sheet. The positive electrode substrate 11 can be, for example, an Al alloy foil. The positive electrode substrate 11 can have a thickness of, for example, 10 μm to 30 μm. The positive electrode active material layer 12 is disposed on the surface of the positive electrode substrate 11. The positive electrode active material layer 12 may, for example, be disposed only on one side of the positive electrode substrate 11. Alternatively, the positive electrode active material layer 12 may, for example, be disposed on both sides of the positive electrode substrate 11. In the width direction of the positive electrode 10 (… Figure 5 Along the X-axis direction, the positive electrode substrate 11 may also be exposed at one end. The positive electrode current collector 71 can be joined to the exposed portion of the positive electrode substrate 11.

[0041] For example, an intermediate layer (not shown) may be formed between the positive electrode active material layer 12 and the positive electrode substrate 11. In this embodiment, even with the intermediate layer present, the positive electrode active material layer 12 is considered to be disposed on the surface of the positive electrode substrate 11. The intermediate layer may be thinner than the positive electrode active material layer 12. The intermediate layer may have a thickness of, for example, 0.1 μm to 10 μm. The intermediate layer may contain, for example, a conductive material, an insulating material, etc.

[0042] The positive electrode active material layer 12 may have a thickness of, for example, 10 μm to 200 μm. The positive electrode active material layer 12 may also have a thickness of, for example, 50 μm to 150 μm. The positive electrode active material layer 12 may also have a thickness of, for example, 50 μm to 100 μm.

[0043] The positive electrode active material layer 12 contains a positive electrode active material. The positive electrode active material is a particle group. In addition to the positive electrode active material, the positive electrode active material layer 12 may also contain additional components. Besides the positive electrode active material, the positive electrode active material layer 12 may also contain, for example, conductive materials and binders. The conductive material can contain any component. For example, the conductive material may contain at least one selected from the group consisting of carbon black, graphite, vapor-grown carbon fiber (VGCF), carbon nanotubes (CNTs), and graphene sheets. The amount of conductive material relative to 100 parts by mass of the positive electrode active material may be, for example, 0.1 parts by mass to 10 parts by mass. The binder can contain any component. For example, the binder may contain at least one selected from the group consisting of polyvinylidene fluoride (PVdF), poly(vinylidene fluoride-co-hexafluoropropylene (PVdF-HFP), polytetrafluoroethylene (PTFE), and polyacrylic acid (PAA). The amount of binder relative to 100 parts by mass of the positive electrode active material may be, for example, 0.1 parts by mass to 10 parts by mass.

[0044] The positive electrode active material layer 12 can have a high density. For example, the positive electrode active material layer 12 can have a density of 3.6 g / cm³. 3 ~3.9g / cm 3 The density of the positive electrode active material layer 12 can also be, for example, 3.65 g / cm³. 3 ~3.81g / cm 3 The density of the positive electrode active material layer 12 can also be, for example, 3.70 g / cm³. 3 ~3.81g / cm 3 The density of the active material layer in this specification refers to the apparent density.

[0045] The negative electrode 20 may include, for example, a negative electrode substrate 21 and a negative electrode active material layer 22. The negative electrode substrate 21 is a conductive sheet. The negative electrode substrate 21 may, for example, be a Cu alloy foil. The negative electrode substrate 21 may have a thickness of, for example, 5 μm to 30 μm. The negative electrode active material layer 22 may be disposed on the surface of the negative electrode substrate 21. The negative electrode active material layer 22 may, for example, be disposed only on one side of the negative electrode substrate 21. The negative electrode active material layer 22 may, for example, be disposed on both sides of the negative electrode substrate 21. In the width direction of the negative electrode 20 ( Figure 5 Along the X-axis direction, the negative electrode substrate 21 may also be exposed at one end. The negative electrode current collector 72 can be joined to the exposed portion of the negative electrode substrate 21.

[0046] The negative electrode active material layer 22 may have a thickness of, for example, 10 μm to 200 μm. The negative electrode active material layer 22 contains a negative electrode active material. The negative electrode active material may contain any component. For example, the negative electrode active material may contain at least one selected from the group consisting of graphite, soft carbon, hard carbon, silicon, silicon oxide, silicon-based alloys, tin, tin oxide, tin-based alloys, and lithium-titanium composite oxides.

[0047] In addition to the negative electrode active material, the negative electrode active material layer 22 may also contain, for example, an adhesive. The negative electrode active material layer 22 may, for example, contain 95% to 99.5% negative electrode active material and the remainder adhesive by mass fraction. The adhesive may contain any components. For example, the adhesive may contain at least one component selected from the group consisting of carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR).

[0048] At least a portion of the separator 30 is located between the positive electrode 10 and the negative electrode 20. The separator 30 separates the positive electrode 10 and the negative electrode 20. The separator 30 may have a thickness of, for example, 10 μm to 30 μm.

[0049] The diaphragm 30 is a porous sheet. Electrolyte permeates through the diaphragm 30. The diaphragm 30 can have an air permeability of, for example, 200 s / 100 mL to 400 s / 100 mL. In this specification, "air permeability" refers to "air resistance" as specified in JIS P8117:2009. Air permeability is determined by the Gurley test method.

[0050] The diaphragm 30 is electrically insulating. The diaphragm 30 may, for example, comprise a polyolefin resin. The diaphragm 30 may, for example, be substantially composed of a polyolefin resin. The polyolefin resin may, for example, comprise at least one selected from the group consisting of polyethylene (PE) and polypropylene (PP). The diaphragm 30 may, for example, have a single-layer structure. The diaphragm 30 may, for example, be substantially composed of a PE layer. The diaphragm 30 may also, for example, have a multi-layer structure. The diaphragm 30 may also be formed, for example, by sequentially layering a PP layer, a PE layer, and another PP layer. A heat-resistant layer, for example, may be formed on the surface of the diaphragm 30.

[0051] The electrolyte comprises a solvent and a supporting electrolyte. The solvent is aprotic. The solvent may contain any components. For example, the solvent may contain at least one selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), 1,2-dimethoxyethane (DME), methyl formate (MF), methyl acetate (MA), methyl propionate (MP), and γ-butyrolactone (GBL).

[0052] The supporting electrolyte is soluble in a solvent. The supporting electrolyte may, for example, comprise at least one selected from the group consisting of LiPF6, LiBF4, and LiN(FSO2)2. The supporting electrolyte may have a molar concentration, for example, from 0.5 mol / L to 2.0 mol / L. The supporting electrolyte may also have a molar concentration, for example, from 0.8 mol / L to 1.2 mol / L.

[0053] In addition to the solvent and supporting electrolyte, the electrolyte may contain any additives. For example, the electrolyte may contain 0.01% to 5% additives by mass fraction. The additives may include at least one selected from the group consisting of vinylene carbonate (VC), lithium difluorophosphate (LiPO2F2), lithium fluorosulfonate (FSO3Li), and lithium bis(oxalato)borate (LiBOB).

[0054] like Figure 4 As shown, the battery unit 100 also includes a detection unit 500. At least a portion of the detection unit 500 is disposed inside the outer casing 90. The detection unit 500 includes a circuit board 93 and an antenna portion 510.

[0055] like Figure 4 As shown, the circuit board 93 is located on the inner surface of the sealing plate 91. Specifically, the circuit board 93 is adhered to the inner surface of the sealing plate 91. The circuit board 93 has a circuit for detecting the state of the battery cell 100. In the circuit board 93, an integrated circuit and electronic components formed on a semiconductor such as Si are mounted on a printed circuit board with insulating function. In this embodiment, an antenna pattern is formed on the printed circuit board.

[0056] The state of the battery cell 100 includes at least one of the following: voltage, internal temperature, and internal pressure. That is, the detection unit 500 detects at least one of the following: voltage, internal temperature, and internal pressure of the battery cell 100.

[0057] Antenna 510 is disposed on circuit board 93. Antenna 510 performs wireless communication. In this embodiment, antenna 510 is disposed inside outer casing 90. Even when antenna 510 is disposed inside outer casing 90, antenna 510 can still transmit and receive electromagnetic waves through insulating members 61, 62 disposed around positive terminal 81 and negative terminal 82. Antenna 510 can also transmit and receive electromagnetic waves, for example, when performing short-range wireless communication conforming to ISO / IEC 18092 or ISO / IEC 14443. It should be noted that antenna 510 can also be led out to the outside of outer casing 90 through injection port 41 or other holes formed in outer casing.

[0058] In this embodiment, short-range wireless communication uses Bluetooth, which transmits signals in a contactless manner, but is not limited to Bluetooth; it can also use the NFC (Near Field Communication) standard. NFC-compliant communication devices are, for example, devices embedded in contactless IC cards such as transit cards and electronic money, or in small mobile devices such as mobile phones and smartphones, that transmit signals in a contactless manner.

[0059] The antenna section 510 of each of the multiple battery cells 100 included in the battery pack 1 is configured to communicate wirelessly with a wireless communication unit, which is electrically connected to a monitoring unit, i.e., a battery management system (BMS), located outside the battery cell 100. The battery management system (BMS) includes a cell management controller (CMC) and a battery management controller (BMC). The battery management system (BMS) is installed within the battery system or in a vehicle, etc. It should be noted that the battery management system (BMS) transmits and receives various signals from the battery ECU (Electronic Control Unit) via communication following the CAN (Controller Area Network) protocol. The detection unit 500 can also connect to an available cloud via a network through bidirectional communication with the antenna section 510.

[0060] Figure 6 This is a circuit diagram showing the electrical connection between the battery cell and the detection unit. For example... Figure 6 As shown, the detection unit 500 is connected to the power supply line L1.

[0061] The power supply line L1 is connected to both the positive collector 71 and the negative collector 72. However, the power supply line L1 may also be connected to only one of the positive collector 71 and the negative collector 72. In this way, the detection unit 500 is electrically connected to the collector and powered.

[0062] Figure 7 This is a functional block diagram representing a specific instance of a detection unit. For example... Figure 7 As shown, the detection unit 500 includes a microcomputer 590. The microcomputer 590 is mounted on the circuit board 93. The microcomputer 590 includes a power control unit 591, a CPU 520, a clock control unit 592, a voltage sensor 540, an analog-to-digital converter 593, a temperature sensor 594, a peripheral function unit 595, a wireless communication function unit 596, a program memory 597, RAM (Random Access Memory) 598, non-volatile memory 599, and a program rewrite control unit 580.

[0063] The microcomputer 590 also includes two power terminals T1, an antenna terminal T2, and two sensor terminals T3. One power terminal T1 is electrically connected to the positive terminal 81 via a power supply line L1. An overcurrent protection fuse 571 is installed on the power supply line L1 connected to the positive terminal 81. The other power terminal T1 is electrically connected to the negative terminal 82 via a power supply line L1. A power input protection component 570 for overvoltage and noise protection is connected between the power supply line L1 connected to the positive terminal 81 and the power supply line L1 connected to the negative terminal 82.

[0064] Antenna terminal T2 is connected to antenna section 510. Antenna section 510 is, for example, a patterned antenna with a meandering shape formed on circuit board 93. It should be noted that the shape and type of antenna section 510 are appropriately set.

[0065] One sensor terminal T3 is connected to a pressure sensor 550. The pressure sensor 550 is disposed inside the battery cell 100 and measures the internal pressure of the battery cell 100. The other sensor terminal T3 is connected to a voltage sensor 560. The voltage sensor 560 is disposed inside the battery cell 100 and is electrically connected to the outer can 92 to measure the potential of the outer can 92.

[0066] The power control unit 591 generates operating power for the microcomputer 590 based on the power supplied from the battery unit 100. Furthermore, the power control unit 591 controls the operating mode of the microcomputer 590. Additionally, the power control unit 591 can generate a reset signal.

[0067] The CPU 520 performs various controls and calculations. The clock control unit 592 generates an operating clock and a communication clock through a built-in oscillator, and controls the operating clock and the communication clock.

[0068] The voltage sensor 540 measures the voltage of the battery cell 100 by detecting the potential difference between one power terminal T1 and the other power terminal T1. It should be noted that the voltage sensor 540 converts the detected potential difference, which is an analog signal, into a voltage parameter value, which is a digital signal, and outputs it.

[0069] The analog-to-digital converter 593 converts the detected values ​​of the analog signals input from the pressure sensor 550 and the voltage sensor 560 into parameter values ​​as digital signals and outputs them.

[0070] Temperature sensor 594 is built into microcomputer 590 and measures the internal temperature of battery cell 100. Peripheral function unit 595 performs peripheral functions of microcomputer 590 required for program operations such as timer operation.

[0071] The wireless communication function unit 596 has an RF (Radio Frequency) transceiver circuit capable of transmitting and receiving signals. The program memory 597, serving as a storage unit, is a rewritable, non-volatile memory that stores the program for operating the microcomputer 590. RAM 598 is a working memory that temporarily stores programs and data.

[0072] The non-volatile memory 599 stores the inherent data and measurement history data of the battery unit 100. The program rewriting control unit 580 rewrites or debugs the program stored in the program memory 597 via wireless communication.

[0073] The microcomputer 590 is capable of detecting the state of the battery cell 100 and controlling its built-in functions based on command signals sent from a wireless communication unit electrically connected to the battery management system (BMS).

[0074] The objects used to detect the state of the battery cell 100 include the voltage of the battery cell 100 detected by the voltage sensor 540, the potential of the outer can 92 detected by the voltage sensor 560, the internal temperature of the battery cell 100 detected by the temperature sensor 594, and the internal pressure of the battery cell 100 detected by the pressure sensor 550.

[0075] Various processes are performed by the microcomputer 590. The status information of the battery cell 100 is converted by A / D conversion and subjected to various signal processing, and then sent to the battery management system (BMS). In addition, various measurement values ​​and measurement history are stored in non-volatile memory 599.

[0076] It should be noted that when there is a deviation in the detected voltage received from the multiple battery cells 100 within the battery pack 1, the battery management system (BMS) sends a command signal to perform cell balancing to equalize the voltage of each battery cell 100. Specifically, a command signal is sent to the battery cell 100 with the highest voltage value to activate the microcomputer 590 or to enable wireless communication. By consuming power through the activation of the microcomputer 590 or wireless communication by the battery cell 100 that received the command signal, the voltage of the multiple battery cells 100 within the battery pack 1 is equalized. In this embodiment, the microcomputer 590 itself or the wireless communication function unit 596 serves as the cell balancing unit for equalizing the voltage of the energy storage cells.

[0077] In the battery cell 100 of this embodiment, by arranging the detection unit 500 inside the outer casing 90, it is possible to suppress the enlargement of the space occupied by the battery cell 100 equipped with the detection unit 500 for wireless communication.

[0078] In the battery cell 100 of this embodiment, the detection unit 500 is electrically connected to the current collector and powered, so there is no need to configure a separate power supply to power the detection unit 500. Therefore, it is possible to suppress the large size of the battery cell 100 that occupies space with the detection unit 500 that performs wireless communication.

[0079] By using a voltage sensor 540 connected between the positive current collector 71 and the negative current collector 72 to measure the voltage of the battery cell 100, the voltage of the battery cell 100 can be measured with high accuracy compared to the case where the voltage of the battery cell 100 is measured via a bus connecting the battery cells 100 to each other.

[0080] By utilizing a pressure sensor 550 configured inside the battery cell 100 to measure the pressure inside the battery cell 100, the pressure inside the battery cell 100 can be measured with high precision.

[0081] By utilizing a temperature sensor 594 disposed inside the battery cell 100 to measure the internal temperature of the battery cell 100, compared to conventional battery cells, temperature can be measured at a location close to the electrode body 50, thereby enabling high-precision measurement of the internal temperature of the battery cell 100. It should be noted that resin can also be used to perform an insulating treatment by coating or casting the circuit board 93. This insulating treatment can prevent internal short circuits in the battery cell 100 caused by metal sheets or the like.

[0082] Hereinafter, a modified example of the battery cell of this embodiment will be described. In the following description of the modified example, the structure that is the same as that of the battery cell 100 of Embodiment 1 will not be described again.

[0083] Figure 8 This is a partial cross-sectional view of the periphery of the antenna section of the battery cell in the first modification of Embodiment 1. (See attached image.) Figure 8 As shown, in the battery cell of the first variation of Embodiment 1, the antenna portion 510a extends through the sealing plate 91 and outwards from the outer casing 90. It should be noted that the antenna portion 510a and the sealing plate 91 are sealed by an insulating sealing member (not shown).

[0084] According to this modified example, by placing the circuit board 93 inside the outer casing 90 and placing only the front end of the antenna portion 510a outside the outer casing 90, it is possible to suppress the enlargement of the battery cell's occupied space and improve the wireless communication characteristics of the detection unit 500A.

[0085] Figure 9 This is an exploded perspective view showing the structure of the detection unit and the outer casing of the battery cell in the second variation of Embodiment 1. Figure 10This is a partial cross-sectional view showing the structure of the detection unit of the battery cell in the second variation of Embodiment 1.

[0086] like Figure 9 as well as Figure 10 As shown, in the battery cell of the second variation of Embodiment 1, the detection unit 500B includes an insulating circuit board 93B having circuitry for detecting the state of the battery cell, and an antenna portion 510 disposed on the insulating circuit board 93B. The insulating circuit board 93B seals the opening of the outer packaging can 92. The antenna portion 510 is located outside the outer packaging.

[0087] The insulating circuit board 93B is made of an insulating resin such as glass epoxy resin. In this modified example, the positive terminal 81 and the negative terminal 82 are directly fixed to a sealing plate made of the insulating circuit board 93B. The insulating circuit board 93B and the outer can 92 are hermetically bonded to each other by a bonding material not shown.

[0088] According to this modified example, by placing the insulating circuit board 93B inside the outer casing and placing the antenna portion 510 outside the outer casing, it is possible to suppress the enlargement of the battery cell's footprint and improve the wireless communication characteristics of the detection unit 500B. Furthermore, since the insulating components 61 and 62 are not required, the number of components can be reduced.

[0089] (Implementation Method 2)

[0090] Hereinafter, the battery cell of Embodiment 2 will be described with reference to the accompanying drawings. The outer casing of the battery cell of Embodiment 2 is pouch-shaped, and the electrode body, which is the main body, is stacked. This is different from the battery cell 100 of Embodiment 1. Therefore, the structure that is the same as that of the battery cell 100 of Embodiment 1 will not be described again.

[0091] Figure 11 This is a top view showing the appearance of the battery cell in Embodiment 2. Figure 12 This is an exploded perspective view showing the structure of the battery cell in Embodiment 2. (Example) Figure 11 as well as Figure 12 As shown, the battery cell 100A of Embodiment 2 includes an outer casing 600, an electrode body 50A, and a detection unit 500.

[0092] The outer casing 600 is constructed by laminating two shrink films. The shrink film is, for example, an aluminum laminate formed by stacking aluminum foil and a resin film. The electrode body 50A is disposed inside the outer casing 600. An electrolyte (not shown) is filled inside the outer casing 600.

[0093] The electrode body 50A is constructed by sequentially stacking a positive electrode 700, a diaphragm 900, and a negative electrode 800. The positive electrode current collector 710, which is part of the positive electrode 700, and the negative electrode current collector 810, which is part of the negative electrode 800, are respectively led out to the outside of the outer casing 600.

[0094] At least a portion of the separator 900 is located between the positive electrode 700 and the negative electrode 800. The separator 900 separates the positive electrode 700 and the negative electrode 800. The separator 900 is a porous sheet. Electrolyte permeates through the separator 900. The separator 900 is electrically insulating.

[0095] The detection unit 500 is disposed inside the outer casing 600 on the negative electrode 800. The detection unit 500 is electrically connected to the negative electrode 800 and is powered thereon. To enable wireless communication of the antenna section, an opening can be provided in the aluminum foil covering the antenna section within the outer casing 600, or only the front end of the antenna section can be located outside the outer casing 600. It should be noted that the antenna section can also be led out to the outside of the outer casing 600 through a hole formed in the outer casing 600.

[0096] In the battery cell 100A of this embodiment, by arranging the detection unit 500 inside the outer casing 600, it is possible to suppress the increase in the space occupied by the battery cell 100A, which includes the detection unit 500 for wireless communication. In addition, compared with an outer casing with an outer can, the pouch-shaped outer casing 600 is smaller, thus effectively suppressing the increase in the space occupied by the battery cell 100A.

[0097] Hereinafter, a modified example of the battery cell of this embodiment will be described. In the following description of the modified example, the structure that is the same as that of the battery cell 100A of Embodiment 2 will not be described again.

[0098] Figure 13 This is a top view showing the appearance of the battery cell in a modified example of Embodiment 2. For example... Figure 13 As shown, in the modified embodiment 2, the detection unit 500 of the battery cell 100B is disposed on the negative electrode current collector 810. The detection unit 500 is electrically connected to the negative electrode current collector 810 and is powered thereon.

[0099] In this modified battery cell 100B, the detection unit 500 is electrically connected to the current collector and powered, thus eliminating the need for a separate power supply for the detection unit 500. Therefore, the increased space occupied by the battery cell 100B, which includes the detection unit 500 for wireless communication, can be prevented. By placing the antenna outside the outer casing 600, the wireless communication characteristics of the detection unit 500 can be improved.

[0100] Embodiments of the invention have been described, but the embodiments disclosed herein should be understood as illustrative rather than restrictive in all respects. The scope of the invention is set forth in the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power storage unit for a battery pack composed of a plurality of power storage units, the battery pack being provided with a battery management system that transmits a command signal for performing unit balancing that equalizes voltages of the power storage units, wherein, The energy storage unit includes: outer body; The main body is disposed inside the outer casing; and A detection unit, at least a portion of which is disposed inside the outer casing, detects the state of the energy storage unit and performs wireless communication. The detection unit includes a unit balancing section that equalizes the voltage of the energy storage units. The unit's balancing mechanism operates using electricity from the energy storage unit. The detection unit includes a microcomputer. The microcomputer includes a wireless communication function unit. The microcomputer or the wireless communication function unit becomes the unit balancing unit. When the detected voltages received from the multiple energy storage units in the battery pack are inconsistent, the battery management system sends a command signal to the energy storage unit with the higher voltage value, causing the microcomputer to operate or to perform wireless communication. Power is consumed by the microcomputer of the energy storage unit that receives the command signal or by the wireless communication function unit performing wireless communication. As a result, the voltages of the multiple energy storage units in the battery pack are equalized.

2. The energy storage unit as described in claim 1, wherein, The energy storage unit also includes a current collector connected to the main body. The detection unit is electrically connected to the current collector and is powered by it.

3. The energy storage unit as described in claim 1 or 2, wherein, The detection unit includes a substrate having circuitry for detecting the state of the energy storage unit and an antenna portion disposed on the substrate. The outer casing includes an outer can with an opening and a sealing plate for sealing the opening of the outer can. The substrate is located on the inner surface side of the sealing plate. The antenna portion extends through the sealing plate or the outer casing and outwards from the outer casing.

4. The energy storage unit as described in claim 1 or 2, wherein, The detection unit includes an insulating substrate having a circuit for detecting the state of the energy storage unit and an antenna portion disposed on the insulating substrate. The outer casing includes an outer can with an opening. The insulating substrate seals the opening of the outer can. The antenna is located outside the outer casing.

5. An energy storage unit for a battery pack consisting of multiple energy storage units, the battery pack comprising a battery management system, the battery management system sending a command signal to perform cell balancing to equalize the voltage of each energy storage unit, wherein... The energy storage unit includes: Main body; A current collector, which is connected to the main body; and The detection unit, electrically connected to and powered by the current collector, detects the status of the energy storage unit and performs wireless communication. The detection unit includes a unit balancing section that equalizes the voltage of the energy storage units. The unit's balancing mechanism operates using electricity from the energy storage unit. The detection unit includes a microcomputer. The microcomputer includes a wireless communication function unit. The microcomputer or the wireless communication function unit becomes the unit balancing unit. When the detected voltages received from the multiple energy storage units in the battery pack are inconsistent, the battery management system sends a command signal to the energy storage unit with the higher voltage value, causing the microcomputer to operate or to perform wireless communication. Power is consumed by the microcomputer of the energy storage unit that receives the command signal or by the wireless communication function unit performing wireless communication. As a result, the voltages of the multiple energy storage units in the battery pack are equalized.

6. The energy storage unit as described in claim 1 or 5, wherein, The detection unit detects at least one of the following states: voltage of the energy storage unit, internal temperature of the energy storage unit, and internal pressure of the energy storage unit.

7. The energy storage unit as described in claim 6, wherein, The detection unit includes a storage unit. The storage unit stores data obtained from detecting the status of the energy storage unit.

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