WO2023282358A1

WO2023282358A1 - Secondary battery module and control method therefor

Info

Publication number: WO2023282358A1
Application number: PCT/JP2022/027268
Authority: WO
Inventors: 英明堀江; 洋志川崎
Original assignee: Ａｐｂ株式会社
Priority date: 2021-07-09
Filing date: 2022-07-11
Publication date: 2023-01-12

Abstract

This secondary battery module comprises: an assembled battery (50) obtained by stacking a plurality of single cells (30); first optical communication units (20, 21) provided respectively to the plurality of cells (40); a control device (23) provided to the plurality of cells (30) and for controlling the first optical communication units (20, 21); an external control device (100) that individually controls the plurality of cells (30); second optical communication units (80, 81) provided to the external control device (100); and an optical waveguide (60) included between the first optical communication units (20, 21) and the second optical communication units (80, 81). The first optical communication units (20, 21) and the second optical communication units (80, 81) are configured to perform two-way communication via the optical waveguide (60), and the external control device (100) is configured to act as a master that manages the control device (23) as a slave. Optical signals can be transmitted and received from each of the plurality of single cells (30) constituting the assembled battery (50) at arbitrary timing without overlapping on the optical waveguide (60).

Description

Secondary battery module and its control method

The present invention relates to a secondary battery module and its control method.

Conventionally, assembled batteries in which multiple single cells made of lithium-ion batteries and the like are stacked are used as power sources for electric vehicles, hybrid electric vehicles, etc., and as power sources for portable electronic devices. When charging such an assembled battery, it is necessary to manage charging so that there is no overcharged unit cell.

In Patent Document 1, an overcharge heat generating circuit including a light emitting diode is connected in parallel to both ends of a battery module including single cells connected in series, and when overcharge occurs, the light emitted from the light emitting diode is a common optical fiber. (eg, paragraphs [0012], [0023] to [0024] of Patent Document 1, see FIG. 5).

JP-A-11-341693

However, the configuration of Patent Document 1 emits light when the unit cell is overcharged and the corresponding light emitting diode is energized. I can't let you know. In addition, since the configuration of Patent Document 1 is a configuration in which the light emitted from the plurality of light emitting diodes is sent to the light receiving diode through a common optical fiber, an additional device for separating the light emitted from the plurality of overlapping light emitting diodes on the common optical fiber is provided. Requires processing.

The present invention has been made in view of such problems, and its object is to provide optical signals from each of a plurality of single cells constituting an assembled battery without overlapping on an optical waveguide and in an arbitrary manner. To provide a secondary battery module and a method for controlling the same, in which data is transmitted and received at the timing of

As a result of intensive studies based on the above knowledge, the inventor has arrived at the following aspects of the invention.

an assembled battery in which a plurality of single cells are stacked;
a first optical communication unit provided in each of the plurality of cells;
a control device provided in the plurality of cells and controlling the first optical communication unit;
an external control device that controls each of the plurality of cells;
a second optical communication unit provided in the external control device;
an optical waveguide provided between the first optical communication unit and the second optical communication unit,
The first optical communication unit and the second optical communication unit are configured to perform two-way communication via the optical waveguide,
A secondary battery module, wherein the external control device is configured to operate as a master that manages the control device as a slave.

an assembled battery in which a plurality of unit cells are stacked; a first optical communication unit provided in each of the plurality of unit cells; and a first optical communication unit provided in the plurality of unit cells to control the first optical communication unit. a control device, an external control device for controlling each of the plurality of cells, a second optical communication unit provided in the external control device, the first optical communication unit and the second optical communication unit and an optical waveguide provided between, wherein the first optical communication unit and the second optical communication unit are configured to perform two-way communication via the optical waveguide, and the external control device is a control method executed in a secondary battery module configured to operate as a master that manages the control device as a slave,
Each of the first optical communication units has a unique light emission timing and a unique light reception timing, the second optical communication unit has a variable light emission timing and a variable light reception timing,
The control method is
the second optical communication unit transmitting a predetermined code by radiating light to the optical waveguide with the variable light emission timing matching the unique light reception timing of the first optical communication unit;
Each of the first optical communication units receives an optical signal by receiving light from the optical waveguide at the unique light receiving timing;
Each of the first optical communication units transmits an optical signal by emitting light to the optical waveguide at the unique light emission timing on condition that the received optical signal matches the predetermined code. and
The second optical communication unit receives an optical signal by receiving light from the optical waveguide with the variable light receiving timing matching the unique light emission timing of the first optical communication unit. A control method for a secondary battery module, comprising:

According to the secondary battery module of the present invention, optical signals are transmitted and received at arbitrary timing without overlapping on the optical waveguide from each of the plurality of single cells forming the assembled battery.

FIG. 1 is a partially cutaway perspective view of a secondary battery module according to an embodiment of the present invention. FIG. 2A is a diagram showing a schematic cross-sectional structure of a cell that is part of a secondary battery module according to one embodiment of the present invention. FIG. 2B is a diagram illustrating a schematic cross-sectional structure of part of the secondary battery module according to one embodiment of the present invention. FIG. 2C is a diagram illustrating another example of the secondary battery module according to the embodiment of the invention shown in FIG. 2B. FIG. 3 is a diagram showing an outline of the configuration of a secondary battery module control device according to an embodiment of the present invention. FIG. 4 is a diagram showing functional blocks of a secondary battery module control device according to an embodiment of the present invention. FIG. 5 is a diagram showing a schematic configuration of an optical communication device provided in a cell of a secondary battery module according to one embodiment of the present invention. FIG. 6 is a flow chart explaining the operation of the secondary battery module according to one embodiment of the present invention. FIG. 7A is a diagram illustrating signals transmitted and received in a secondary battery module according to an embodiment of the present invention and transmitted from a control device. FIG. 7B is a diagram illustrating signals transmitted and received in the secondary battery module according to one embodiment of the present invention, and signals received by the single-cell optical communication device. FIG. 7C is a diagram illustrating signals transmitted and received in the secondary battery module according to the embodiment of the present invention, and signals received by the single-cell optical communication device. FIG. 7D is a diagram illustrating signals transmitted and received in the secondary battery module according to the embodiment of the present invention, and signals received by the single-cell optical communication device. FIG. 8 is a flow chart explaining the operation of the secondary battery module according to one embodiment of the present invention. FIG. 9 is a flow chart explaining the operation of the secondary battery module according to one embodiment of the present invention. FIG. 10 is a perspective view showing an example in which battery cells according to a modification of the present embodiment are stacked in multiple stages. FIG. 11 is a perspective view showing an example in which a battery cell is composed of a single layer. FIG. 12 is a side sectional view of a secondary battery module. FIG. 13A is a plan view of the positive current extraction layer viewed from above. FIG. 13B is a plan view of the positive current extraction layer viewed from above. FIG. 14 is a plan view showing another form of the positive electrode side current extraction layer viewed from above. FIG. 15A is a plan view of the negative electrode-side current supply layer viewed from below. FIG. 15B is a plan view of the negative electrode-side current supply layer viewed from below. FIG. 16A is an enlarged cross-sectional view of a battery cell as a lithium ion secondary battery. FIG. 16B is an enlarged cross-sectional view of a battery cell as a lithium ion secondary battery. FIG. 17 is a perspective view showing an example of forming an assembled battery in which a plurality of battery cells are stacked and connected. FIG. 18 is a plan view showing an example in which a plurality of current take-out units each including a current take-out portion, a plurality of positive electrode conductive lines, and a positive electrode junction portion are provided. FIG. 19 is a plan view showing an example in which a plurality of battery cells having one current extraction unit provided on one positive electrode current collector are provided. FIG. 20A is a cross-sectional view showing an example in which a small hole penetrating from the upper end to the lower end is formed in the positive current extraction layer. FIG. 20B is a cross-sectional view showing an example in which a small hole penetrating from the upper end to the lower end is formed in the positive current extraction layer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or similar reference numerals indicate the same or similar elements, and repeated descriptions may be omitted. It goes without saying that the numerical values and materials described below are exemplary and, therefore, the embodiments of the present invention can be implemented using other numerical values and materials without departing from the scope of the invention.

A secondary battery module according to an embodiment of the present invention includes a plurality of stacked unit cells constituting an assembled battery, a plurality of optical communication devices provided in each of the plurality of unit cells, and the plurality of optical communication devices. a control device for controlling each of a plurality of cells, an optical communication device provided in the control device, and a plurality of optical communication devices provided in the plurality of cells and provided in the control device and an optical waveguide provided between the optical communication device. The secondary battery module includes a control device (controlling the plurality of optical communication devices) provided in each of the plurality of cells, and a control device provided in each of the plurality of cells. In contrast to the control device provided for each of the plurality of cells, a control device that controls each of the plurality of cells is also called an external control device. The external control device is configured to operate as a master that manages the control device provided for each of the plurality of cells as a slave. With such a configuration, the external control device operating as a master controls the transmission of optical signals from the optical communication device provided in each cell via the control device managed as a slave, whereby each cell can be transmitted and received at arbitrary timing without overlapping on the optical waveguide. In one example described below, the communication device provided in each unit cell has a unique identification code, and unique light emission timing and unique light reception timing. The communication device provided in each cell receives light from the optical waveguide at a unique light receiving timing to receive an optical signal, and emits light to the optical waveguide at a unique light emitting timing to transmit the optical signal. is configured to Further, the communication device provided in each unit cell emits light to the optical waveguide at a unique light emission timing to transmit the optical signal, provided that the received optical signal matches the unique identification code. It is configured. The optical communication device provided in the control device has variable light emission timing and variable light reception timing. The optical communication device provided in the control device radiates light to the optical waveguide by matching the variable light emission timing with the unique light reception timing of the optical communication device provided in the cell selected from the plurality of cells. By doing so, it is configured to transmit the unique identification code of the optical communication device provided in the cell. Further, the optical communication device provided in the control device matches the variable light receiving timing with the light emission timing unique to the optical communication device provided in the single cell selected from the plurality of single cells, and emits light from the optical waveguide. It is configured to receive an optical signal by receiving light.

FIG. 1 is a partially cutaway perspective view of a secondary battery module according to one embodiment of the present invention. The secondary battery module of this embodiment is, for example, a lithium ion battery module. More preferably, it is a battery that is highly safe and requires low monitoring density (low frequency of collecting information on temperature and voltage conditions). An example in which a secondary battery module according to an embodiment of the present invention is configured by a lithium ion battery module will be described below.

As shown in FIG. 1, the lithium ion battery module 1 has a plurality of stacked single cells 30 . The lithium-ion battery module 1 also has an optical waveguide 60 arranged adjacent to or in close proximity to the light-emitting surface of the light-emitting portion 20 and the light-receiving surface of the light-receiving portion 21 . Furthermore, the lithium-ion battery module 1 has an exterior body 70 that accommodates the plurality of cells 30 and the optical waveguides 60 .

A plurality of stacked single cells 30 constitute an assembled battery 50 . Although FIG. 1 shows a configuration in which five cells 30 are stacked, more or less than five cells may be stacked. In one implementation, the number of stacks of cells 30 may be 20 or more.

A conductive sheet is provided on the uppermost negative electrode current collector of the assembled battery 50 . A part of the conductive sheet is drawn out from the outer package 70 to form the lead wiring 57 . A conductive sheet is provided under the positive electrode current collector on the bottom surface of the assembled battery 50 . A part of the conductive sheet is pulled out from the exterior body 70 to form the lead wiring 59 .

Each unit cell 30 has a light emitting unit 20 for transmitting the measured characteristics of the unit cell, such as temperature and voltage, to the outside as an optical signal, and a light receiving unit 21 for receiving an optical signal from the outside. .

The optical waveguide 60 has an optical input/output portion from which an incident and propagated optical signal is emitted. In one implementation example, light emitted from the light emitting units 20 provided in each of 20 or more single cells 30 arranged adjacent or close to one optical waveguide 60 is optically coupled to form an optical input/output unit. emitted from In this embodiment, a portion of the optical waveguide 60 is pulled out from the exterior body 70 to serve as an optical input/output section. An optical signal emitted from the optical input/output unit is received by the light receiving unit 80 . Further, the optical waveguide 60 propagates an optical signal incident from the light emitting portion 81 to the optical input/output portion. In this way, through one optical waveguide 60, the external light receiving section 80 and light emitting section 81 and the light emitting section 20 and light receiving section 21 of the plurality of cells 30 perform two-way communication by half-duplex communication. Using a pair of two optical waveguides 60, i.e., one optical waveguide 60 for communication from the external light emitter 81 to the light receivers 21 of the plurality of cells 30 and from the light emitters 20 of the plurality of cells 30 to the outside. By using another optical waveguide 60 for communication to the light receiving unit 80 of the external light receiving unit 80 and light emitting unit 81 and the light emitting unit 20 and light receiving unit 21 of the plurality of cells 30 by full duplex communication Two-way communication may be performed. The entire optical waveguide 60 including the optical input/output section may be housed inside the exterior body 70 . When the entire optical waveguide 60 is housed inside the exterior body 70 , the optical signal emitted from the optical input/output portion is received by the light receiving section 80 arranged inside the exterior body 70 , and is also received inside the exterior body 70 . An optical signal incident from the arranged light emitting portion 81 propagates toward the unit cell 30 .

FIG. 2A is a diagram showing a schematic cross-sectional structure of a cell that is part of a secondary battery module according to one embodiment of the present invention. FIG. 2B is a diagram illustrating a schematic cross-sectional structure of part of the secondary battery module according to one embodiment of the present invention. FIG. 2C is a diagram illustrating another example of the secondary battery module according to the embodiment of the invention shown in FIG. 2B.

As shown in FIG. 2A, each unit cell 30 has a positive electrode current collector 17, a positive electrode active material layer 15, a separator 14, a negative electrode active material layer 11, and a negative electrode current collector 19 stacked in this order from the bottom. It is. The single cell 30 includes a positive electrode 12 in which a positive electrode active material layer 15 is formed on the surface of a positive electrode current collector 17 having a substantially rectangular flat plate shape, and a negative electrode active material layer 15 formed on the surface of a negative electrode current collector 19 having a substantially rectangular flat plate shape. A negative electrode 13 having a material layer 11 formed thereon is laminated with a substantially flat separator 14 interposed therebetween. The unit cell 30 has an annular frame member 18 arranged between the positive electrode current collector 17 and the negative electrode current collector 19 , and the frame member allows the separator 14 to be placed between the positive electrode current collector 17 and the negative electrode current collector 19 . , and seals the positive electrode active material layer 15 , the separator 14 and the negative electrode active material layer 11 .

FIG. 2A shows the light-emitting part 20 and the light-receiving part 21 arranged on the wiring board 24 . The wiring board 24 , the light emitting section 20 and the light receiving section 21 constitute an optical communication device provided in the cell 30 . In addition to the control circuit 23 that controls the light emitting section 20 and the light receiving section 21, a voltage sensor and a temperature sensor may be arranged on the wiring board 24. FIG. For example, part of the light receiving part 21 and the light emitting part 20 is embedded in the frame member 18 and fixed with the insulating resin 25 so as to be exposed from the surface of the frame member 18 that contacts the outside. The surface of the frame member 18 in contact with the outside may be a side surface substantially parallel to the stacking direction of the cells 30, or a concave surface having an opening on the side surface and facing the cell 30 from the side surface (cell 30 may be a surface substantially perpendicular to or substantially parallel to the stacking direction of 30). At least a portion of the light receiving surface of the light receiving unit 21 and at least a portion of the light emitting surface of the light emitting unit 20, or at least a portion of the light receiving unit 21 including the light receiving surface and at least a portion of the light emitting unit 20 including the light emitting surface are the frame member 18. By arranging so that it is exposed from the surface in contact with the outside of the frame member 18, the optical signal is transmitted to the outside without being blocked by the frame member 18. - 特許庁

Two cells 30 adjacent to each other in the assembled battery 50 are stacked such that the upper surface of the negative electrode current collector 19 of one cell 30 and the lower surface of the positive electrode current collector 17 of the other cell 30 are adjacent to each other. .

FIG. 2B is a diagram showing a schematic cross-sectional structure of part of the secondary battery module according to one embodiment of the present invention. FIG. 2B illustrates a structure in which a portion of the optical waveguide 60 is pulled out from the exterior body 70 and becomes an optical input/output section. As shown in FIG. 2B , the optical waveguide 60 extending in the stacking direction of the unit cells 30 is arranged adjacent to or close to the light emitting surface of the light emitting section 20 and the light receiving surface of the light receiving section 21 . The optical waveguide 60 may be, for example, an optical fiber, or may be a light guide plate having a sufficient width (length in the direction perpendicular to the stacking direction of the cells) to receive the optical signal from the light emitting section 20 . When the optical waveguide 60 is composed of a light guide plate, the width dimension of the optical waveguide 60 is the maximum dimension of the light emitting surface of the light emitting part 20 and the light receiving part 21 (the diameter if the light emitting surface and the light receiving surface are circular, and the diagonal if the light emitting surface and the light receiving surface are rectangular). ) should be larger than FIG. 2B shows a case where the optical waveguide 60 is configured using a light guide plate.

When a light guide plate is used as the optical waveguide 60, the optical waveguide 60 is arranged so as to cover all of the light emitting surfaces of the plurality of light emitting portions 20 and the light receiving surfaces of the light receiving portions 21 (each corresponding to the plurality of stacked unit cells 30). can be placed. In addition, the light emitting direction of the light emitting unit 20 and the light receiving direction of the light receiving unit 21 (including the case where the light emitting surface and the light receiving surface are aligned with the vertical direction and the case where the light emitting surface and the light receiving surface are inclined from the vertical direction) are covered. An optical waveguide 60 can be arranged.

When a light guide plate is used as the optical waveguide 60 in this way, compared to the case where an optical fiber is used as the optical waveguide 60, the optical signal output from the light emitting unit 20 is more likely to enter the light guide plate, and the light output from the light guide plate Positioning of the optical waveguide, which makes it easier for the signal to enter the light receiving portion 21, thereby eliminating the need for additional parts such as lenses for condensing the optical signal between the light emitting portion 20 and the light receiving portion 21 and the optical waveguide 60. is reduced, or the allowable amount of misalignment is increased. Of course, in order to increase the coupling efficiency of optical signals between the light guide plate as the optical waveguide 60 and the light emitting section 20 and the light receiving section 21, additional parts such as lenses may be used. may be used. Even when one or both of an additional component such as a lens and a light-condensing light guide plate are used, compared to the case of using an optical fiber as the optical waveguide 60, the complexity of positioning can be reduced or the position can be reduced. The deviation allowance is increased. Although the optical waveguide 60 extending in the stacking direction of the unit cells is exemplified, it is also possible to use the optical waveguide 60 extending in a direction orthogonal to the stacking direction of the unit cells. In this case, the light guide plate as the optical waveguide 60 can cover all of the light emitting surfaces of the plurality of light emitting units 20 and the light receiving surfaces of the light receiving units 21 .

As shown in FIG. 2B, the optical waveguide 60 corresponds to the position of the back surface corresponding to the position of the surface receiving the optical signal from the light emitting unit 20 or the position of the surface emitting the optical signal to the light receiving surface of the light receiving unit 21. Scattering processing 60a is applied to the position of the back surface. The scattering processing 60a is applied to positions corresponding to the light-emitting surface of the light-emitting portion 20 and the light-receiving surface of the light-receiving portion 21 adjacent or close to each other. The scattering processing 60a can be, for example, uneven processing. A portion of the optical signal that enters the optical waveguide 60 and is scattered by the scattering processing 60a propagates in the direction of the optical output section.

In addition, the optical waveguide 60 is subjected to reflection processing 60b in the bent portion, so that the optical signal scattered by the bent portion can be reflected in the direction of the optical input/output portion. In addition, reflection processing 60b is applied to the end opposite to the end serving as the light input/output portion of the optical waveguide 60 and the bent portion. can be reflected in the direction of the optical input/output section.

FIG. 2C illustrates a structure in which the entire optical waveguide 60 including the optical input/output section is accommodated inside the exterior body 70, which is another example of FIG. 2B. When the entire optical waveguide 60 is accommodated inside the exterior body 70, a lead-out portion is not required as shown in the optical waveguide 60 shown in FIG. 2B. An optical signal emitted from the optical input/output part in the exterior body 70 is received by the light receiving part 80 arranged adjacent to the optical waveguide 60 inside the exterior body 70 , and is received by the optical waveguide 60 inside the exterior body 70 . An optical signal incident from the adjacently arranged light emitting portion 81 propagates toward the unit cell 30 . The optical signal received by the light receiving unit 80 is converted into an electric signal and transmitted to the control unit 90 outside the exterior body 70 via the lead wiring 82 . An electrical signal from the control unit 90 outside the exterior body 70 is transmitted to the interior of the exterior body 70 via the lead wire 83 and converted into an optical signal by the light emitting section 81 .

FIG. 3 is a diagram showing a schematic configuration of a control device for a secondary battery module according to one embodiment of the present invention. The control device 100 includes a control section 90, a light receiving section 80, and a light emitting section 81 arranged on a control board (not shown). The control device 100 has an oscillator such as a crystal oscillator (not shown) on its substrate, and supplies a relatively high-precision clock to the control section 90 . The control device 100 may be powered by the lithium-ion battery module 1 or may be powered by another power source.

The control unit 90 controls the variable light emission timing of the light emitting unit 81 and the variable light receiving timing of the light receiving unit 80 as described later. The controller 90 may be a general-purpose processor or a dedicated processor. The processor may have built-in storage or may cooperate with external storage (not shown).

The light emitting section 81 can be configured using an LED element or the like. The light receiving section 80 can be configured using a photodiode, a phototransistor, or the like. The light-receiving section 80 may be configured using an LED element, which is a light-emitting element, as a light-receiving element. The light emitting unit 81 and the light receiving unit 80 constitute an optical communication device.

The time interval from ON to OFF of the light emission of the light emitting unit 81 (corresponding to the pulse width of one light pulse transmitted from the light emitting unit 81) is controlled by the control unit 90 and is variable. Here, it is called variable light emission timing. The time interval (corresponding to the pulse width of one light pulse) from ON to OFF of light sampling by the light receiving unit 80 is controlled and variable by the control unit 90 . Here, it is called variable light receiving timing.

FIG. 4 is a diagram showing functional blocks of a control device for a secondary battery module according to one embodiment of the present invention. The control unit 90 functions as a light emission timing setting unit 91 , a light reception timing setting unit 92 , a cell selection unit 93 , a cell information storage unit 94 , a cell timing measurement unit 95 and a cell timing setting unit 96 .

The light emission timing setting unit 91 sets the variable light emission timing of the light emitting unit 81 to transmit the optical signal. The light receiving timing setting section 92 sets the variable light receiving timing of the light receiving section 80 in order to receive the optical signal.

The unit cell information storage unit 94 stores information on the plurality of unit cells 30 that make up the assembled battery 50 . The information of the single cell 30 includes, for example, a unique identification code, a unique light emission timing, a unique light reception timing, etc. possessed by the optical communication device of each single cell.

The unit cell selection unit 93 selects targets for transmitting and receiving optical signals from among the plurality of unit cells 30 . The unit cell selection unit 93 reads the unique identification code, the unique light emission timing, or the unique light reception timing of the optical communication device of the unit cell 30 selected from the unit cell information storage unit 94, and sets the light emission timing setting unit 91 or the light reception timing. It is supplied to the setting section 92 .

The single cell timing measurement unit 95 measures (determines) the unique light emission timing and unique light reception timing of the single cell 30 by the method described with reference to FIG. The unit cell timing measurement unit 95 stores the unique light emission timing and the unique light reception timing of the unit cell 30 in the unit cell information storage unit 94 .

The single cell timing setting unit 96 sets the unique light emission timing and unique light receiving timing of the plurality of single cells 30 forming the assembled battery 50 by the method described with reference to FIG. Adjustments are made so that the unique light emission timings and unique light receiving timings of the plurality of cells 30 do not overlap. The single cell timing setting unit 96 stores the set unique light emission timing and unique light receiving timing of the single cell 30 in the single cell information storage unit 94 .

FIG. 5 is a diagram showing a schematic configuration of an optical communication device provided in a cell of a secondary battery module according to one embodiment of the present invention. The communication device includes a control circuit 23, a light emitting section 20, and a light receiving section 21 arranged on a wiring board 24. FIG. The communication device is driven by the corresponding cell 30 as a power source. A sensor (not shown) for measuring the measured temperature and voltage of the cell may also be arranged on the wiring board 24 .

The control circuit 23 controls the light emitting section 20 to transmit an optical signal in response to a predetermined code from the control device 100 received via the light receiving section 21 . The control circuit 23 can consist of a microcontroller with a CR (capacitor, resistor) oscillator. Since the CR oscillator consumes less power than the crystal oscillator, it is possible to reduce the power consumption of the cell 30, which is the power supply. The accuracy of CR oscillators is lower and more variable than that of crystal oscillators. This embodiment utilizes the accuracy feature of the CR oscillator. Further, the control circuit 23 may reset the transmitter in response to a predetermined code (reset code) from the control device 100 received via the light receiving section 21 . Alternatively, the control circuit 23 may set the light receiving timing of the light receiving unit 21 and the light emitting timing of the light emitting unit 20 in response to a predetermined code (setting code) received from the control device 100 via the light receiving unit 21 .

The light emitting section 20 and the light receiving section 21 can be configured similarly to the light emitting section 81 and the light receiving section 80 . Since the transmission frequencies of the CR oscillators of the plurality of unit cell communication devices constituting the assembled battery 50 are different, the light emission timing of the light emission unit 20 of each optical communication device (time interval from light emission ON to OFF (transmission from the light emission unit 20 (pulse width of one optical pulse)) and light receiving timing of the light receiving unit 21 (time interval from ON to OFF of sampling of light (pulse width of one optical pulse)) are unique according to the accuracy of the CR oscillator. is the timing. Further, when the control circuit 23 resets the oscillator in response to the reset code, the light emission timing specific to the light emitting unit 20 and the light receiving timing specific to the light receiving unit 21 are also reset. Independent of the accuracy of the CR oscillator, the control circuit 23 responds to the setting code so that the light emission timing of the light emitting unit 20 and the light receiving timing of the light receiving unit 21 of each communication device are different from each other. may be set. A setting code from the control device 100 to the optical communication device of the cell 30 may indicate the offset. The light emission timing of one light emitting unit 20 and the light receiving timing of the light receiving unit 21 are equal, but they may be set differently.

Although it has been described that the optical communication device provided in the unit cell of the secondary battery module is configured to be driven using the corresponding unit cell 30 as a power supply, the electric power converted from the optical signal by the light receiving unit 21 It may be configured to drive using signal power as a power source. For example, a capacitor (not shown) for storing the power of the electrical signal converted from the optical signal by the light receiving unit 21 is provided on the wiring board 24, and the stored power is used as the power of the electrical signal converted from the optical signal. Accordingly, an element included in the control circuit 23 may be driven, or the light emitting section 20 may be driven to transmit an optical signal. In this case, power can be supplied from the control device 100 to drive the optical communication device provided in the unit cell through the transmission of the optical signal, and the power consumption of the unit cell by the optical communication device can be reduced. becomes possible.

FIG. 6 is a flow chart explaining the operation of the secondary battery module according to one embodiment of the present invention. By the operation shown in FIG. 6, the control device 100 allows optical signals to be transmitted and received from each of the plurality of single cells 30 forming the assembled battery at arbitrary timing without overlapping on the optical waveguide. In FIG. 6, the object to which the control device 100 transmits and receives the optical signal is indicated as the cell 301, and the remaining cells are indicated as the cell 30k ( _k ≠ ₁ ).

In S<b>501 , the control device ₁₀₀ (cell selection unit 93 ) selects the cell 301 .

In S<b>502 , the control device 100 ( _single cell selection unit 93 ) reads the light emission timing and light reception timing unique to the optical communication device of the selected cell 301 from the cell information storage unit 94 .

In S<b>503 , the control device 100 (light emission timing setting unit 91 ) sets the variable light emission timing of the optical communication device of the control device 100 to the read unique light reception timing, and transmits a predetermined code (light signal) through the light emission unit 81 . ). After that, the process proceeds to S508. For example, the predetermined code may include any code known to the optical communication device of the plurality of cells 30, plus or additionally _a unique identification code of the optical communication device of the selected cell 301. may contain. The predetermined code may include an error detection code to improve detection accuracy of the cell 30 in the optical communication device.

FIG. 7A schematically shows _an optical signal transmitted in S503 by matching the light receiving timing specific to the unit cell 301 for which the variable light emitting timing is selected. The optical signal is composed of 1010101 optical pulse trains, and the pulse width of each optical pulse is determined by the unique light receiving timing of the optical communication device of the unit cell 301 ( _each optical pulse of the optical pulse train sampled and decoded by the light receiving unit 21). pulse width).

In S508, the control device 100 (control unit 90) determines whether or not a predetermined time has elapsed, and returns to S503 if the predetermined time has elapsed.

In S504, each of the light receiving units 21 of the

cells

30 ₁ and 30 _k receives light and decodes it at a unique light receiving timing.

FIG. 7B schematically shows an optical pulse train received and decoded by the light receiving section 21 of the cell 301. The pulse width of each decoded optical pulse matches the pulse width of each optical pulse in the optical pulse train shown in FIG. 7A. 7C and 7D schematically show an optical pulse train received and decoded by the light receiving section 21 of the cell _30k . The pulse width of each optical pulse decoded at the unique light receiving timing of the optical communication device of the _single cell _30k different from the unique light receiving timing of the optical communication device of the single cell 301 is equal to that of each light of the optical pulse train shown in FIG. 7A. Does not match the pulse width of the pulse.

At S505, the control circuits 23 of the

cells

30 ₁ and 30 _k determine whether the decoded optical signal matches a known predetermined code.

If the decoded optical signal matches the known predetermined code (YES in S505), the process proceeds to S506, and the control circuit 23 of the cell 301 transmits _an optical signal via the light emitting section 20 at a unique light emission timing. do.

If the decoded optical signal does not match the known predetermined code (NO in S505), the process proceeds to S507, and the control circuit 23 of the cell _30k does not transmit the optical signal.

In S509, the control device 100 (light receiving timing setting unit 92) sets the variable light receiving timing of the optical communication device of the control device 100 to the read unique light emitting timing, and transmits a signal (optical signal) through the light receiving unit 80. receive.

By the operation described above with reference to FIG. 6, the control device 100 allows the optical signal to be optically guided at an arbitrary timing with the unit cell selected from the plurality of unit cells 30 constituting the assembled battery. Optical signals can be transmitted and received without overlapping on the road.

FIG. 8 is a flow chart explaining the operation of the secondary battery module according to one embodiment of the present invention. The operation of measuring (determining) the unique light emission timing and unique light reception timing of the optical communication device of the cell 30 and storing them in the cell information storage unit 94 will be described with reference to FIG. The operation of FIG. 8 is an operation of measuring (determining) the unknown unique light emission timing and unique light reception timing of the optical communication device of the cell 30 by trial and error. The operation of FIG. 8 can be performed before the operation of reading the timing specific to the unit cell selected in S502 of FIG. 6, or as an additional operation or an alternative operation to the operation. _A case will be described where the unknown unique light emission timing and unique light reception timing of the optical communication device of the unit cell 301 are measured (determined) by the operation of FIG.

In S701, the control device 100 (light emission timing setting unit 91) selects or changes the variable light emission timing of the optical communication device of the control device 100. The variable light emission timing and variable light reception timing of the optical communication device can range from the minimum value to the maximum value that can be set based on a relatively high-precision clock such as a crystal oscillator provided in the control device 100, for example. Between the minimum and maximum values of the variable light emission timing and the variable light reception timing, there is included the light emission timing and light reception timing unique to the optical communication device of the single cell 30 based on the CR oscillator, which has lower precision than the crystal oscillator. In this case, in S701, it is possible to sequentially select (change) from the minimum value to the maximum value of the variable light emission timing.

In S702, the control device 100 (light emission timing setting unit 91) sets the variable light emission timing of the optical communication device of the selected (changed) control device 100, and transmits a predetermined code (optical signal) through the light emission unit 81. Send. After that, the process proceeds to S707. The predetermined code may include, for example, _any code known to the optical communication device of the plurality of unit cells 30, similar to S503 in FIG. A unique identification code for the optical communication device may be included. Further, the predetermined code may include an error detection code to improve detection accuracy in single cell optical communication devices. Assume that the optical signal transmitted in S702 is the same as in FIG. 7A.

In S707, the control device 100 (control unit 90) determines whether or not a predetermined time has elapsed, and returns to S701 if the predetermined time has elapsed.

In S703, each of the light receiving units 21 of the

cells

At S704, the control circuits 23 of the

cells

In S704, if the decoded optical signal becomes the optical pulse train shown in FIG. 7B and matches the predetermined code (YES in S704), the process proceeds to S705.

In S704, the decoded optical signal becomes the optical pulse train shown in FIG. 7C or FIG. 7D, and if it does not match the known predetermined code (NO in _S704 ), proceed to S706 to The control circuit 23 does not transmit optical signals.

In S705, the control circuit 23 of the cell 301 transmits _an optical signal via the light emitting section 20 at a unique light emission timing. The control circuit 23 of cell 30 1 can transmit a unique identification (ID) code as an optical signal to indicate that the optical signal is being transmitted from cell 30 ₁ .

In S708, the control device 100 (light receiving timing setting unit 92) sets the variable light emission timing of the optical communication device of the control device 100 selected (changed) in S701, and transmits a signal (optical signal) via the light receiving unit 80. receive.

On the condition that the signal is received in S708, in S709, the control device 100 (single cell timing measurement unit) determines that the variable light emission timing and the variable light reception timing of the optical communication device of the control device 100 selected (changed) in S701 are , is determined to be the timing of light reception and the timing of light emission unique to the optical communication device of the _single cell 301, and is stored in the single cell information storage unit 94 in association with the unique identification (ID) code of the optical communication device of the single cell 301. Remember.

In S710, the control device 100 (single cell timing measuring unit) determines whether or not the unique identification (ID) codes of the optical communication devices of all the single cells 30 are stored in association with the unique light emission timing and light reception timing. . If the unique identification (ID) codes of the optical communication devices of all the cells 30 are not stored (NO in S710), the process returns to S701. When the unique identification (ID) codes of the optical communication devices of all the cells 30 have been stored, the operation shown in FIG. 8 ends.

By the operation described above with reference to FIG. 8, the control device 100 can know the specific light emission timing and specific light reception of the plurality of single cells 30 constituting the assembled battery.

FIG. 9 is a flow chart explaining the operation of the secondary battery module according to one embodiment of the present invention. Referring to FIG. 9, when control device 100 transmits a predetermined code including a setting code to the optical communication device of a specific cell 30 to the optical communication device of cell 30, the optical communication device of cell 30 The operation of setting the light emission timing and the unique light reception timing of is explained. When the reset code is used as the setting code, the operation of FIG. Allows you to reset timings. Also, in the operation of FIG. 9, when the setting code indicates the offset of the unique light emission timing and the unique light reception timing, the operation of FIG. It is possible to set the unique light emission timing and the unique light reception timing of the optical communication device of a plurality of single cells 30 so as to be different from each other. A case of setting the unique light emission timing and the unique light reception timing of the optical communication device of the unit cell _30k by the operation of FIG. 9 will be described.

In S801, similarly to S701, the control device 100 (light emission timing setting unit 91) selects and changes the variable light emission timing of the optical communication device of the control device 100.

In S802, the control device 100 (light emission timing setting unit 91) sets the variable light emission timing of the optical communication device of the selected (changed) control device 100, and transmits a predetermined code (optical signal) through the light emission unit 81. Send. After that, the process proceeds to S807. The predetermined code may be a unique identification (ID) code for the optical communication device of the cell 30k. Further, the predetermined code may include an error detection code to improve detection accuracy in single cell optical communication devices.

In S807, the control device 100 (control unit 90) determines whether a predetermined time has elapsed, and returns to S801 if the predetermined time has elapsed.

In S803, the light receiving unit 21 of the cell _30k receives light and decodes it at a unique light receiving timing.

At S804, the control circuit 23 of the cell _30k determines whether the decoded optical signal matches the unique identification (ID) code of the optical communication device of the cell _30k .

In S804, if the decoded optical signal does not match the unique identification (ID) code of the optical communication device of the cell _30k (NO in S804), the process proceeds to S805, and the control circuit 23 of the cell _30k Send no signal.

In S804, if the decoded optical signal matches the unique identification (ID) code of the optical communication device of the unit cell _30k (YES in S804), the process proceeds to S806.

In S806, the control circuit 23 of the cell _30k transmits an optical signal via the light emitting section 20 at a unique light emission timing. The control circuit 23 of the cell _30k can transmit a unique identification (ID) code as an optical signal to indicate that the optical signal is being transmitted from the cell _30k .

In S808, the control device 100 (the light receiving timing setting unit 92) sets the variable light receiving timing corresponding to the variable light emitting timing of the optical communication device of the control device 100 selected (changed) in S801. Receive a signal (optical signal).

In S809, the control device 100 (cell timing setting unit 96) determines whether the received optical signal matches the unique identification (ID) code of the optical communication device of the cell _30k .

If the received optical signal does not match the unique identification (ID) code of the optical communication device of the unit cell _30k , the optical signal is assumed to be transmitted from the optical communication device of a unit cell other than the unit cell _30k , and the process proceeds to S801. return.

If the received optical signal matches the unique identification (ID) code of the optical communication device of the unit cell _30k , in S810, a predetermined code (optical signal) is transmitted at the variable light emission timing selected and set in S801. . The predetermined code (optical signal) can be setting information (setting code, optical signal) for setting unique timing. Additionally or alternatively, the predetermined code (optical signal) may include a unique identification code of the optical communication device of the unit cell _30k to be measured. Further, the predetermined code may include an error detection code to improve detection accuracy in single cell optical communication devices. The setting code may be a reset code for resetting a transmitter such as a CR oscillator, and may indicate a unique light emission timing and a unique light reception timing offset.

In S811, the light receiving unit 21 of the unit cell _30k receives light and decodes it at a unique light receiving timing. Thereby, the setting code (reset code, information indicating the offset) is decoded.

In S812, the control circuit 23 of the cell _30k sets the unique light emission timing and light reception timing of the optical transmitter of the cell _30k according to the decoded setting code (reset code, information indicating offset). If the setting code is a reset code, the control circuit 23 resets the oscillator. Through resetting the oscillator, the intrinsic light emission timing and light reception timing are reset. If the setting code indicates an offset, the control circuit 23 offsets the inherent light emission timing and light reception timing. As a result, the pulse width of one optical pulse transmitted from the light emitting unit 20 of the optical communication device of the unit cell 30 _k and the pulse width of one optical pulse received by the light receiving unit 21 are offset. The pulse width of one optical pulse transmitted from the light emitting unit 20 and the pulse width of one optical pulse received by the light receiving unit 21 of the optical communication device are different.

[Modification]
Modifications of the above-described embodiment will be described below. In this modified example, a case in which a current extraction layer, which will be described later, is added to the above-described embodiment, eg, the secondary battery module described with reference to FIGS.

In a stacked battery with a structure in which multiple lithium-ion batteries (single cells) are stacked, the shape of the main surface of the stacked battery (the end face in the stacking direction of a stacked battery in which almost planar batteries are stacked) is placed on both ends in the stacking direction. A current collector (current extraction portion) having substantially the same shape as the current collector is arranged, and the current collectors at both ends are connected to electrode tabs (terminals). This electrode tab is drawn out of the battery package.

As a path through which current flows in this stacked battery, a certain region (hereinafter also referred to as a specific region) on the main surface of the positive electrode current extraction portion (the end surface in the stacking direction of the stacked battery) is provided from the electrode tab connected to the positive electrode current extraction portion. ), and through a certain portion on the main surface of the laminated battery that is in contact with this specific region, to a certain region (hereinafter also referred to as a specific region) on the main surface of the negative electrode current extraction portion that is in contact with the same portion. , to the electrode tab connected to the negative electrode current extraction part. In a conventional stacked battery, the electric resistance is usually not uniform in each specific region of the current path. If the electrical resistance is not uniform, relatively large current flows in areas with relatively low electrical resistance, and the current is distributed during charging and discharging. In the route corresponding to such a specific region, charging and discharging are repeated at a relatively deeper depth than in the other routes, which accelerates deterioration of the battery and may shorten the life of the stacked battery.

According to this modification, in addition to the various effects of the above-described embodiment, it is possible to suppress current distribution during charging and discharging of the battery, suppress deterioration of the battery, and extend the life of the battery. A secondary battery module that can

A secondary battery module to which the present invention is applied will be described in detail below with reference to the drawings.

10 and 11 are perspective views showing a secondary battery module 1 to which the present invention is applied. 12 is a side sectional view of FIG. 11; FIG. In the secondary battery module 1, a negative electrode 2 composed of a negative electrode current collector 51 and a negative electrode active material layer 52, and a positive electrode 3 composed of a positive electrode active material layer 54 and a positive electrode current collector 55 are laminated with a separator 53 interposed therebetween. Battery cells 40 each formed of a single cell on a flat plate are stacked in a plurality of stages. That is, the battery cell 40 constituting the secondary battery module 1 has a negative electrode current collector 51, a negative electrode active material layer 52, a separator 53, a positive electrode active material layer 54, and a positive electrode current collector 55 stacked upward. , is formed in a substantially rectangular flat plate shape as a whole.

10 to 12 are opposite in polarity to FIGS. 1 and 2A to 2C in the above-described embodiment, and correspond to the state in which FIGS. 1 and 2A to 2C are turned upside down. .

The secondary battery module 1 further includes an annular frame member 9 arranged around the periphery of the battery cells 40 . The frame member 9 supports the separator 53 by embedding the end portion of the separator 53, and the frame member 9 brings the positive electrode current collector 55 and the negative electrode current collector 51 into surface contact with the upper surface and the lower surface thereof. They are fixed on top of each other. By fixing the peripheral edge portions of the negative electrode current collector 51, the positive electrode current collector 55, and the separator 53 via the frame member 9, the negative electrode active material layer 52 and the positive electrode active material layer 54 are firmly prevented from leaking to the outside. It becomes possible to seal to Further, the frame member 9 can determine the positional relationship among the negative electrode current collector 51 , the separator 53 , and the positive electrode current collector 55 . The gap between the negative electrode current collector 51 and the separator 53 and the gap between the separator 53 and the positive electrode current collector 55 are adjusted in advance according to the capacity of the battery. The negative electrode current collector 51, the separator 53, and the positive electrode current collector 55 can be fixed to each other.

Further, although illustration and description are omitted in this modified example, as described in the above embodiment, the battery cell 40 includes the light emitting unit 20 and the light emitting unit 20 arranged on the wiring board 24, as in FIGS. A communication device or the like having a light receiving portion 21 and a control circuit 23 is provided, and the secondary battery module 1 includes an optical waveguide 60, a control device 100 having a light emitting portion 81, a light receiving portion 80, and a control portion 90. is provided.

It should be noted that the secondary battery module 1 may also be configured without the communication device, the optical waveguide 60, the control device 100, and the like. Moreover, as shown in FIGS. 11 and 12, the secondary battery module 1 does not have a communication device, an optical waveguide 60, a control device 100, and the like, and is composed of a single layer without stacking the battery cells 40. is also conceivable.

On the lower side of the negative electrode current collector 51, the negative electrode side current extraction layer 10 is laminated in a planar shape, and on the upper side of the positive electrode current collector 55, the positive electrode side current extraction layer 16 is similarly laminated in a planar shape.

When the battery cells 40 are stacked in multiple stages as shown in FIG. 10, the positive current extraction layer 16 and the negative current extraction layer 10 should be in contact with at least one surface of the outermost layer.

The electricity storage element composed of the negative electrode current collector 51, the negative electrode active material layer 52, the separator 53, the positive electrode active material layer 54, and the positive electrode current collector 55 described below is an example. , a negative electrode active material layer 52, a separator 53, and a positive electrode active material layer 54 are provided, and the positive electrode side current extraction layer 16 and the negative electrode side current extraction layer 10 may be in contact with at least one surface of the outermost layer.

The positive electrode-side current extraction layer 16 is formed on the upper surface of the positive electrode current collector 55 and is made of an insulator. As shown in FIG. 10, the positive electrode-side current extraction layer 16 is divided into current extraction portions 6 corresponding to a plurality of sections.

The partitions are provided in substantially uniform shapes and positions in the positive electrode side current extraction layer 16 and the negative electrode side current extraction layer 10 to be described later. The term "substantially uniform shape" as used herein means not only uniformity in terms of mutual shapes, but also uniformity in area. Also, the respective regions are not limited to a completely equal relationship, and may be approximately equal (substantially equal).

A current flows from the battery cell 40 to the current extractor 6 . This section is configured by dividing the back side of the positive electrode current extraction layer 16 . The current extraction part 6 may be completely physically separated in the positive electrode side current extraction layer 16, but is not limited to this. Although not physically separated, an apparent boundary is provided. It may be as small as it is. The term "apparent boundary" as used herein refers to a mere boundary allocated for design purposes, that is, a single positive current extraction layer 16 that has no boundary as a whole, although it is separated as a boundary on the design drawing. It may be configured. Also, the current extractor 6 corresponding to this section may be physically clearly separated. In such a case, the positive electrode current extraction layers 16 are separated by an insulator or the like so as to form mutually independent sections. When the positive electrode-side current extraction layer 16 is physically divided into a plurality of compartments, not only the positive electrode-side current extraction layer 16 but also the negative electrode current collector 51, the negative electrode active material layer 52, the separator 53, and the positive electrode, which constitute the battery cell 40. The active material layers 54 may also be similarly separated via an insulator or the like.

FIG. 13A is a plan view of the positive electrode-side current extraction layer 16 viewed from above when focusing on one current extraction portion 6 . The current extracting ends 36 a to 36 d are electrically connected to the positive current collector 55 . A plurality of positive electrode conductive wires 22a to 22d are provided for electrically connecting the current extraction end portions 36a to 36d to the positive electrode merging portion 26. As shown in FIG. Hereinafter, the current extraction end portion 36, the positive electrode conductor wire 22, and the positive electrode junction portion 26 are also referred to as a current extraction wire. The lengths from the current extracting ends 36a to 36d of the positive electrode conductors 22a to 22d to the positive electrode junction portion 26 are substantially the same. The term “substantially the same” as used herein is not limited to the case where the lengths are completely the same. The current extraction portion 6 in the positive electrode side current extraction layer 16 is divided into a plurality of regions 32a to 32d having substantially uniform upper surfaces. The term "substantially uniform" as used herein means that the shapes of the regions 32a to 32d are completely symmetrical, and the regions 32a to 32d have the same area. is slightly off from perfect symmetry, and an error may occur in the areas between the regions 32a to 32d.

Incidentally, in the above-described embodiment, the electric resistances from the current extraction ends 36a to 36d of the positive electrode conductors 22a to 22d to the positive electrode junction portion 26 may be substantially the same. The positive electrode conductors 22a to 22d may have different materials, lengths, and diameters as long as they have substantially the same electrical resistance. It is preferable that the electrical resistances are approximately equal to each other if they are 20% or less, and more preferably 10% or less or 5% or less.

These areas 32a to 32d do not need to consist of areas that are clearly physically separated, and may be areas that are not physically separated and are separated beyond what they appear to be. The term "apparent division" as used herein means a division allocated in design, that is, although it is divided as a region on the design drawing, it is actually a positive electrode side current extraction layer 16 that does not have any division as a whole. It may be configured. Also, the regions 32a to 32d may be composed of physically distinct regions. In such a case, the positive current extraction layer 16 is separated by an insulator or the like so as to form independent regions 32a to 32d. When the positive electrode current extraction layer 16 is physically divided into a plurality of regions 32a to 32b, not only the positive electrode current extraction layer 16 but also the negative electrode current collector 51, the negative electrode active material layer 52, and the separator that constitute the battery cell 40. 53 and the positive electrode active material layer 54 may be similarly separated via an insulator or the like.

In the example of FIG. 13A, the regions 32a to 32d are formed by equally dividing the positive electrode side current extraction layer 16, which is square in plan view, into four parts, and are exactly square in plan view. However, the regions 32a to 32d are not limited to having such a shape, and if the positive electrode-side current extraction layer 16 is rectangular in plan view, it can be It may be configured in a rectangular shape divided into four.

In the example of FIG. 13A, the case where the positive current extraction layer 16 is divided into four regions 32a to 32d has been described as an example. It may be configured by being divided. Even in such a case, it is assumed that the regions 32 are configured to be equal to each other. It may be understood that there is. Also, the respective regions are not limited to a completely equal relationship, and may be approximately equal (substantially equal).

The current extraction ends 36a-36d are provided substantially at the center of the above-described regions 32a-32d. The positive electrode confluence portion 26 is located at the center of the positive electrode current collector 55 composed of the regions 32a to 32b, and is provided at a confluence point where the boundaries of the regions 32a to 32b intersect each other at one point. In the example of FIG. 13A, positive electrode conductive wires 22a to 22d extend linearly toward the positive electrode confluence portion 26 from current extracting ends 36a to 36d provided substantially at the center of regions 32a to 32d. That is, the positive electrode conductors 22a to 22d are linearly extended toward the positive junction 26 from the current extraction ends 36a to 36d provided substantially at the center of the regions 32a to 32d that are evenly provided. , it is obvious that the lengths are geometrically the same. In this manner, the lengths of the positive electrode conductors 22a to 22d are designed to be the same as each other, but they do not necessarily have to be exactly the same, and there is some length deviation between the positive electrode conductors 22a to 22d. is acceptable. From the positive junction 26, an extraction wiring 8 made of a conductor layer for supplying current to the electric circuit during discharge is connected. That is, one extraction wiring 8 connected to the positive junction 26 is assigned to each current extraction portion 6 . The extraction wiring 8 for extracting this current, and the current extraction line including this, are provided independently for each current extraction section 6, so that the current is independently extracted for each current extraction section 6 corresponding to the section. becomes possible. Note that the lead wiring 8 may be drawn out side by side with the lead wiring 7 in the same manner as the lead wiring 57 in FIG. 1 of the above-described embodiment.

The example of FIG. 13B shows an example in which the configurations of the positive electrode conductive wire 22 and the positive electrode junction portion 26 are omitted. 13B, at least one lead wire 8 extending from one current take-out end 36 is provided in each current take-out portion 6 corresponding to the section. It may be extended. Note that, even in such a case, the lead wiring 8 may be branched in different directions along the way. Also, in the example shown in FIG. 13B, the concept of the area 32 may be abstracted.

It should be noted that it is not essential that the positive electrode current collector 55 is formed at the center of the positive electrode current collector 55 composed of the regions 32a to 32b. For example, as shown in FIG. It may be

In the present invention, the wiring composed of the current extracting ends 36a to 36d, the positive electrode conductors 22a to 22d, and the positive electrode merging portion 26 is not essential, and at least the wiring provided with the current extracting end 36 is used. It is good if there is At this time, the current extraction end portion 36 is configured to penetrate the positive electrode current extraction layer 16 from the upper end to the lower end, so that when another circuit is connected to the upper portion of the positive electrode current extraction layer 16, It is possible to improve convenience.

The negative electrode-side current extraction layer 10 is formed on the lower surface of the negative electrode current collector 51 as shown in FIG. 15A, and is made of an insulator. In other words, in the negative electrode current extraction layer 10, a plurality of current extraction end portions 35a to 35d are connected to the lower surface of the negative electrode current collector 51 as conductors. The current extracting ends 35 a to 35 d are electrically connected to the negative electrode current collector 51 .

Similarly to the positive current extraction layer 16, the negative current extraction layer 10 is also divided into a plurality of current extraction portions 6' corresponding to the divisions. A current flows from the battery cell 40 to the current extractor 6'. This current extraction portion 6' may be completely physically separated in the negative electrode side current extraction layer 10, but is not limited to this. may be provided. Further, the current extracting portion 6' may be configured by physically separating the negative current extracting layer 10 clearly. In such a case, the negative current extraction layers 10 are separated by an insulator or the like so as to form independent current extraction portions 6'. When the negative electrode-side current extraction layer 10 is physically divided into the current extraction portions 6′ corresponding to a plurality of sections, not only the negative electrode-side current extraction layer 10 but also the negative electrode current collector 11 and the negative electrode active layer constituting the battery cell 40 are used. The material layer 52, the separator 53, and the positive electrode active material layer 54 may be similarly separated via an insulator or the like.

A plurality of negative electrode conductive wires 21a to 21d are provided for electrically connecting the current extraction end portions 35a to 35d to the negative electrode junction portion 25. Hereinafter, the current extraction end portion 35, the negative electrode conductor wire 21, and the negative electrode junction portion 25 are also referred to as current extraction wires. The lengths from the current extracting ends 35a to 35d of the negative electrode conductors 21a to 21d to the negative junction 25 are substantially the same. Similarly to the positive current extraction layer 16, the negative current extraction layer 10 has a lower surface divided into a plurality of regions 31a to 31d that are substantially equal to each other. Details of the regions 31a to 31d are the same as those of the regions 32a to 32d described above.

In this case also, the electrical resistances from the current extraction end portions 35a to 35d of the negative electrode conductors 21a to 21d to the negative electrode junction portion 25 may be substantially the same. The negative electrode conductors 21a to 21d may have different materials, lengths, and diameters as long as they have substantially the same electric resistance. It is preferable that the electrical resistances are approximately equal to each other if they are 20% or less, and more preferably 10% or less or 5% or less.

The current extraction ends 35a-35d are provided substantially at the center of the above-described regions 31a-31d. The negative junction 25 is located at the center of the negative current extraction layer 10 composed of the regions 31a to 31d, and is provided at a junction where the boundaries of the regions 31a to 31d intersect at one point. That is, the negative electrode conductors 21a to 21d are linearly extended toward the negative junction 25 from the current extraction ends 35a to 35d provided substantially at the center of the regions 31a to 31d which are evenly provided. , it is obvious that the lengths are geometrically the same. In this way, the lengths of the negative electrode conductors 21a to 21d are designed to be the same as each other, but they do not necessarily have to be exactly the same, and the lengths of the negative electrode conductors 21a to 21d are slightly different. is acceptable. The negative junction 25 is connected to a lead wire 7 made of a conductor layer to which current is supplied from the electric circuit during discharge. That is, one lead wire 7 connected to the negative junction 25 is assigned to the current extraction portion 6' corresponding to each section. The extraction wiring 7 for extracting the current, and the current extraction line including this, are provided independently for each current extraction section 6' according to the section, so that the current is independently extracted for each current extraction section 6'. supply becomes possible.

It should be noted that it is not essential to form the negative electrode junction portion 25 at the center of the negative electrode current extraction layer 10 consisting of the regions 31a to 31d, and it is formed at a location other than the center of the negative electrode current extraction layer 10. may

In this modification, the wiring composed of the current extraction ends 35a to 35d, the negative electrode conductors 21a to 21d, and the negative electrode merging portion 25 is not essential. It is good if it is. At this time, the current extraction end portion 35 is configured to pass through the negative electrode current extraction layer 10 from the upper end to the lower end, so that when another circuit is connected to the lower portion of the negative electrode current extraction layer 10, It is possible to improve convenience.

The example of FIG. 15B shows an example in which the configuration of the negative electrode conductive wire 21 and the negative electrode junction portion 25 is omitted. In other words, each current take-out portion 6' corresponding to the section is provided with at least one lead wire 7 extending from one current take-out end portion 35 as shown in FIG. 15B. It may be extended outside. Also in this case, the lead wiring 7 may be branched in different directions along the way. Also, in the example shown in FIG. 15B, the concept of the area 32 may be abstracted.

The battery cell 40 is composed of a so-called lithium ion secondary battery. FIG. 16A shows an enlarged cross-sectional view of a battery cell 40 as a lithium ion secondary battery. The constituent positive electrode active material layer 54 contains the positive electrode active material 42 and the electrolytic solution 43 .

When such a battery cell 40 is operated as a lithium-ion secondary battery, the positive electrode terminal of a charger (not shown) is first connected to the positive electrode 3 side, and the negative electrode terminal of the charger is connected to the negative electrode 2 side, and current is supplied. As a result, electrons separated from the positive electrode active material 42 containing lithium-transition metal composite oxide or the like flow through an external circuit including a charger and reach the negative electrode active material 41 made of a carbonaceous material or the like. In the meantime, positively charged lithium ions are attracted to the negative electrode 2 side, flow through the electrolytic solution 43, reach the negative electrode active material 41, and are occluded therein. When all the lithium atoms in the positive electrode active material 42 reach the negative electrode active material 41, the battery cell 40 is in a fully charged state.

An external load (not shown) is connected between the positive electrode 3 and the negative electrode 2 during discharging. As a result, the lithium ions occluded in the negative electrode active material 41 return to a stable state as part of the lithium-transition metal composite oxide, so they pass through the electrolyte 43 and move toward the positive electrode. Energy is also consumed when electrons flow from the negative electrode 2 through an external load to the positive electrode 3 side.

The material forming the negative current extraction layer 10 and the positive current extraction layer 16 may be composed of insulating resin such as epoxy resin and polytetrafluoroethylene, or may be made of carbon fiber or the like. It may be composed of an elastic material that can be elastically deformed, such as a non-woven fabric. The material forming the negative current extraction layer 10 and the positive current extraction layer 16 may be made of any kind of resin such as polyethylene (PE) or polypropylene (PP).

The positive electrode current extraction layer 16, and the current extraction end portion 36, the positive electrode conductive wire 22, and the positive junction 26 included in the positive electrode current extraction layer 16 are functionally classified like a so-called printed circuit board. good. That is, even if the positive current extraction layer 16 is made of an insulator on the printed circuit board, and the current extraction end portion 36, the positive conductive wire 22, and the positive junction 26 are configured as wiring on the printed circuit board. good.

The negative electrode current extraction layer 10, and the current extraction end portion 35, the negative electrode conductive wire 21, and the negative junction 25 included in the negative electrode current extraction layer 10 are functionally classified like a so-called printed circuit board. good. That is, even if the negative current extraction layer 10 is composed of an insulator on the printed circuit board, and the current extraction end portion 35, the negative electrode conductive wire 21, and the negative junction 25 are configured as wiring on the printed circuit board. good.

When the positive electrode side current extraction layer 16 and the negative electrode side current extraction layer 10 are composed of an insulator on a printed circuit board, the material thereof may be a paper substrate impregnated with phenol resin, or a paper substrate impregnated with epoxy resin. impregnated material, glass cloth (woven glass fabric made of glass fibers) impregnated with epoxy resin, paper base material impregnated with polyimide resin, glass cloth base material with fluorine It can be composed of material impregnated with resin, glass cloth substrate impregnated with PPO (Poly Phenylene Oxide) resin, substrate based on metal such as aluminum, or glass ceramic based It may be composed of a substrate.

By classifying the functions like the printed circuit board, it is possible to reduce the contact resistance when connecting directly to other circuits or printed circuit boards (not shown). In addition, by forming the positive electrode current extraction layer 16 and the negative electrode current extraction layer 10 with a hard printed circuit board, the current extraction end portion 35, the negative electrode conductive wire 21, the negative junction portion 25, and the current extraction end portion can be formed. 35, the negative electrode conductive wire 21, and the negative electrode merging portion 25, it is possible to improve the easiness of the work. As a result, it is possible to enhance the convenience in providing the wiring described above.

The positive current extraction layer 16 and/or the negative current extraction layer 10 may be composed of a flexible printed circuit board, and the flexible printed circuit board is composed of a so-called double-sided board in which circuit boards are formed on both sides. may

By constructing a flexible printed circuit board with a double-sided board in this way, it is possible to increase the degree of freedom in wiring, and since the design is easy, there is the advantage that the equal length can be improved from one side. In addition to this, by configuring the flexible printed circuit board with a double-sided board, since it includes a through hole between the surfaces from the front surface to the back surface and a conductive part that penetrates between the surfaces, the heat of the battery cell 40 is transferred to the outside of the battery. It also has the advantage of increasing the ability to escape.

Of course, this flexible printed circuit board may be composed of a single-sided board in which a circuit board is formed only on one side instead of a so-called double-sided board. Although this single-sided board is slightly inferior to double-sided boards in terms of wiring design and thermal conductivity in the vertical direction of the board, it has excellent cost performance and can be configured with a thin board, so in terms of energy density. is also excellent. Even when the positive electrode side current extraction layer 16 and/or the negative electrode side current extraction layer 10 are configured by such a flexible printed circuit board, the current extraction portions 6, 6' are configured corresponding to a plurality of sections, and the current extraction sections 6, 6' are configured corresponding to each section. It has a current lead-out line independent from the current lead-out portions 6, 6'.

Thus, in this modification, the current extraction portion is divided into a plurality of sections in the current extraction layer, and each section has an independent current extraction line. In a configuration of a known stacked battery (for example, a configuration in which an electrode tab (terminal) is connected to a current collector (current extraction portion) in the outermost layer of the stacked battery), current concentrates in a part of the current extraction portion. In contrast to this, in the present embodiment, the current extraction portion is divided into a plurality of sections, each of which has a current extraction line, so the current extraction portions are dispersed. Therefore, compared with the configuration of a known stacked battery, in this modified example, the concentration of current in a certain portion of the current extraction portion is suppressed, so that the distribution of current can be suppressed. By suppressing the current distribution, it is possible to suppress the repetition of deep charging and discharging in a certain part of the laminated battery, thereby suppressing deterioration of the battery.

Note that the wiring width and wiring thickness of the

lead wirings

7 and 8 provided in each section may be defined based on the following equation (1).

Maximum current/number of sections<(wiring thickness (oz)/35)×wiring width (mm) (1)
The maximum current referred to here is the maximum current that flows through the negative current extraction layer 10 and the positive current extraction layer 16 . The left hand side of equation (1) is the maximum current per compartment, obtained by dividing this maximum current by the number of compartments. Since the wiring width and wiring thickness of the

lead wirings

7 and 8 need only exceed the maximum current per section, the wiring thickness (oz) and the wiring width (mm) having the relationship shown on the right side of the equation (1) must be designed with The relationship shown on the right side of the equation (1) is based on the general rule in the industry that a wire with a thickness of 35 oz and a wire width of 1 mm can withstand up to 1 A.

For example, if the maximum current is 20A and the number of sections is 36, the maximum current per section is 0.55A. In this case, for example, if the wiring thickness is 70 oz and the wiring width is 0.5 mm, it exceeds 0.55 A, which is the right side of the formula (1), so that the formula (1) is satisfied.

Incidentally, in order to design the wiring with a thickness of 70 oz, if the positive electrode side current extraction layer 16, the negative electrode side current extraction layer 10, and the printed circuit board constituting these layers are too thin, it becomes difficult to mount the

lead wires

7 and 8 themselves. . For this reason, it is desirable that the thickness of the positive current extraction layer 16, the negative current extraction layer 10, and the thickness of the printed circuit board constituting these layers be 100 μm or more.

Moreover, it is desirable that the number of partitions is 4 or more and 40 or less. The lower limit of the number of sections is the electrode area (cm ^{2 )/400 of the battery cell 40 as a single battery, and the upper limit of the number of sections is the electrode area (cm 2} ⁾ /400 of the battery cell 40 as the single battery. It may be calculated.

The current extraction end portion 36, the positive electrode conductive wire 22, the positive junction portion 26, and the lead wire 8 included in the positive electrode side current extraction layer 16 are plated with gold to suppress corrosion of the printed circuit board due to the potential of the battery. can be done. Similarly, the current extraction end portion 35, the negative electrode conductive wire 21, the negative electrode junction portion 25, and the lead wire 7 are plated with gold to suppress corrosion of the printed circuit board due to the potential of the battery.

Materials constituting the current take-out end portion 36, the positive electrode conductive wire 22, and the positive electrode junction portion 26 include metal materials such as copper, aluminum, titanium, stainless steel, nickel, and alloys thereof, baked carbon, and conductive polymers. material, conductive glass, and the like. At this time, the current extracting end portion 36, the positive electrode conductive wire 22, and the positive electrode junction portion 26 may be composed of a resin current collector made of a conductive polymer material, and constitute the resin current collector. As the conductive polymer material, for example, a conductive polymer or a matrix resin to which a conductive filler made of a conductive filler is added as needed may be used. The materials forming the current extracting end portion 35 , the negative electrode conductive wire 21 , and the negative electrode junction portion 25 are the same as those of the current extracting end portion 36 , the positive electrode conductive wire 22 , and the positive electrode junction portion 26 .

The material constituting the frame member 9 is not particularly limited as long as it has adhesiveness to the negative electrode current collector 51 and the positive electrode current collector 55 and is durable to the electrolytic solution 43 . Materials, especially thermosetting resins, are preferred. Specific examples of the material forming the frame member 9 include epoxy-based resin, polyolefin-based resin, polyurethane-based resin, and polyvinylidene fluoride resin. preferable.

As a method for manufacturing the battery cell 40 composed of the unit cell having the above-described configuration, for example, the negative electrode current collector 51, the negative electrode active material layer 52, the separator 53, the positive electrode active material layer 54, and the positive electrode current collector 55 are stacked in this order. After that, the electrolytic solution 43 is injected, the outer peripheries of the negative electrode active material layer 52, the separator 53 and the positive electrode active material layer 54 are sealed with the frame member 9, and further the negative electrode side current extraction layer 10 and the positive electrode side current extraction layer 16 are formed. It can be obtained by layering. At that time, the current extraction end portion 35, the negative electrode conductive wire 21, the negative electrode junction portion 25, the current extraction end portion 36, the positive electrode wire 22, and the positive electrode junction portion 26 are also formed. As a method for sealing the outer periphery of the negative electrode active material layer 52 and the positive electrode active material layer 54 with the frame member 9, the negative electrode active material layer 52 and the positive electrode active material layer 54 are bonded to the upper and lower surfaces of one of the frame members 9. A lithium-ion secondary battery consisting of a single cell by a method of bonding and sealing one frame member 9 and the other frame member 9 in a state where the separator 53 is inserted in the other frame member 9. A cell 40 can be obtained.

In addition, in the battery cell 40 having the above-described configuration, the battery cell 40' configured with a so-called all-solid lithium ion battery, which uses a solid electrolyte 46 as shown in FIG. 16B instead of the liquid electrolytic solution 43, is substituted. You may do so. In the battery cell 40 ′, the configuration of the separator 53 is omitted, and the entire area from the negative electrode 2 to the positive electrode 3 is filled with the solid electrolyte 46 . In the negative electrode active material layer 52 , the negative electrode active material 41 is interposed in the solid electrolyte 46 . In the cathode active material layer 54 , the cathode active material 42 is interposed in the solid electrolyte 46 . The details and materials of the components that make up the battery cell 40′ are the same as the components that make up the battery cell 40, so the same reference numerals are used to omit the description below. do.

The solid electrolyte 46 includes known solid polymer electrolytes such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof. The solid electrolyte 46 contains a supporting salt (lithium salt) to ensure ionic conductivity. LiBF ₄ , LiPF ₆ , LiN(SO ₂ CF ₃ ) ₂ , LiN(SO ₂ C ₂ F ₅ ) ₂ , or a mixture thereof can be used as the supporting salt. However, polyalkylene oxide polymers such as PEO and PPO that constitute the solid electrolyte 46 are lithium such as LiBF ₄ , LiPF ₆ , LiN(SO ₂ CF ₃ ) ₂ and LiN(SO ₂ C ₂ F ₅ ) ₂ . It has the property of being able to dissolve salts well, and by forming a crosslinked structure between the two, excellent mechanical strength can be exhibited.

According to the battery cell 40' using the above-described solid electrolyte 46 as an electrolyte, since the electrolyte has no fluidity, a sealing structure for preventing the electrolyte from flowing out becomes unnecessary, and the configuration of the secondary battery module 1 is simplified. becomes possible. In addition, according to the battery cell 40', by using a solid electrolyte, it is possible to prevent liquid leakage, prevent liquid junction, which is a problem specific to lithium ion secondary batteries, and improve reliability. can be improved.

It should be noted that the secondary battery module 1 to which the present invention is applied is not limited to the case where the battery cells 40 of the lithium ion secondary battery are composed of single cells. For example, as shown in FIGS. 10 and 17, an assembled battery 50 may be formed by stacking and connecting a plurality of battery cells 40 .

When forming such an assembled battery 50, by connecting a plurality of battery cells 40 in series, the lead wiring 8 provided in the positive electrode side current extraction layer 16 of the battery cell 40 at the top and the battery at the bottom are connected. A current may be freely supplied through the extraction wiring 7 provided in the negative current extraction layer 10 of the cell 40 . In such a case, the battery cells 40 that are connected to each other are stacked such that the lower surface of the negative electrode current extraction layer 10 and the upper surface of the positive electrode current extraction layer 16 are adjacent to each other. Furthermore, when forming such an assembled battery 50, a plurality of battery cells 40 may be connected in parallel, or series connection and parallel connection may be combined. A high capacity and high output can be obtained by configuring the assembled battery 50 in this manner. Alternatively, the

lead wires

7 and 8 connected to the negative current extraction layer 10 and the positive current extraction layer 16 of each battery cell 40 may be configured to independently supply current.

Next, the operation of the secondary battery module 1 to which the present invention is applied will be explained.

When an external load (not shown) of the secondary battery module 1 is connected between the positive electrode 3 and the negative electrode 2 during discharge, electrons reaching the negative electrode current collector 51 from the negative electrode active material layer 52 are transferred to the negative electrode. It is collected at the current extraction end 35 connected to the current collector 51 . Since the current extraction end 35 is provided in each of the regions 31a to 31d, the electrons in each of the regions 31a to 31d in the current extraction portion 6' corresponding to each section are transferred to the current provided for each region 31. They will gather at the extraction end 35 . The electrons collected at each current extracting end 35 are collected to the negative junction 25 via the negative conductive line 21 and sent to the external circuit via the lead wire 7 . Similarly, electrons trying to propagate on the positive electrode current collector 55 are sent from the external circuit to the positive electrode junction portion 26 via the lead wiring 8 . The electrons sent to the positive electrode junction portion 26 are sent to the current extraction end portion 36 via the positive electrode conductive wire 22 . Since the current extraction end 36 is provided in each of the regions 32a to 32d, the electrons in each of the regions 32a to 32d propagate to the positive electrode current collector 55 that constitutes the region 32, and the electrons in the region 32 It propagates to the positive electrode active material layer 54 .

If the above-described operation is explained in terms of current flow instead of electron flow, the current in each of the regions 32a to 32d in the positive electrode current extraction layer 16 is generated by the current extraction terminal provided in the center of each region 32. The current is extracted independently for each current extraction portion 6' by the portion 36. FIG. The current extracted by each current extraction end portion 36 flows through the positive electrode conductor wire 22 to the positive electrode junction portion 26, and flows from the positive electrode junction portion 26 through the lead wire 8 to the external circuit. A current from an external circuit flows into the negative junction 25 through the lead wire 7 provided in each current extraction portion 6', branches from here to each negative electrode conductive wire 21, and reaches the current extraction end portion 35. . Since the current extracting end portion 35 is provided for each of the regions 31a to 31d, the current can flow through the regions 31a to 31d.

In addition, during discharge, the lithium ions occluded in the negative electrode active material 41 move toward the positive electrode active material 42 . Since it is obvious that the lithium ions try to move toward the positive electrode active material 42 in the shortest possible distance, the movement path is perpendicular to the longitudinal direction x and parallel to the thickness direction z. , and linear.

Under the premise of such current flow and lithium ion migration path, the current in each of the regions 32a to 32d in the positive electrode-side current extraction layer 16 flows through the current extraction end 36 provided in the center of each region 32. is taken out by That is, the currents are dispersed in each of the regions 32 a to 32 d and extracted to the current extracting end portion 36 , and the extracted currents are dispersed and flow through the positive electrode conductor wire 22 to be sent to the positive electrode junction portion 26 . Similarly, the current that has flowed into the negative electrode confluence portion 25 is dispersed and branched to each of the negative electrode conductive wires 21 to reach the current extraction end portion 35 .

Similarly, the current in each current extraction portion 6 in the positive current extraction layer 16 is extracted via the current extraction end portion 36 , the positive electrode conductor wire 22 , and the positive electrode junction portion 26 . Similarly, the current that has flowed into the negative electrode is distributed to the respective current extraction portions 6 ′, branched to the respective negative electrode conductive wires 21 , and reaches the current extraction end portion 35 .

Similarly, in the negative electrode, the current from the external circuit flows into the negative electrode confluence portion 25, and from there it is dispersed in each negative electrode conductive wire 21 and reaches the current extraction end portion 35. Since the current extracting end portion 35 is provided for each of the regions 31a to 31d, the current can flow through the regions 31a to 31d. As a result, the current flowing through the negative electrode current collector 51 can be distributed without being concentrated in one pole.

As a result, the current supplied to the negative electrode current collector 51 and the current extracted from the positive electrode current collector 55 can be distributed without being concentrated in the negative electrode current extraction layer 10 and the positive electrode current extraction layer 16 . As a result, the current flowing through each negative electrode conductive line 21 and each positive electrode conductive line 22 can be reduced, and the resistance can be decreased. In addition to this, since the paths of the current flowing through the negative electrode current extraction layer 10 and the positive electrode current extraction layer 16 via the negative electrode conductive wires 21 and the positive electrode conductive wires 22 have the same propagation distance, The uniformity of the resistance in the current extraction layer 10 and the positive current extraction layer 16 can be achieved. As a result, according to the present invention, the resistance can be made uniform between the specific regions without generating a local resistance distribution on the negative current extraction layer 10 and the positive current extraction layer 16, and the current can be reduced. can flow evenly. Therefore, in the path corresponding to the specific area, charging and discharging with a relatively deep depth are not repeated compared to other paths, so that deterioration of the battery can be prevented and the life of the battery can be extended.

In this way, on the positive electrode side, a plurality of positive electrode conductive wires 22 are provided for electrically connecting each current extraction end portion 36 to the positive electrode junction portion 26, and the electrical resistance of the positive electrode conductive wires 22 is , are substantially identical to each other. In particular, the current extraction end portions 36 are provided at substantially even positions in the positive electrode side current extraction layer 16 . As a result, the current to be extracted from the positive electrode current extraction layer 16 can be extracted more evenly between the plurality of current extraction end portions 36, and the current can be distributed and distributed to the plurality of positive electrode conductive wires 22. This eliminates the occurrence of a portion where a large amount of current flows locally. At this time, the positive current extraction layer 16 is divided into a plurality of regions 32 that are substantially equal to each other, and each current extraction end portion 36 is provided substantially at the center of each region 32, so that the positive current extraction layer The current to be tapped at 16 can be tapped more evenly between the plurality of current tapping ends 36 .

Similarly, on the negative electrode side, a plurality of negative electrode conductive wires 21 are provided for electrically connecting each current extraction end portion 35 to the negative electrode junction portion 25, and the electrical resistance of the negative electrode conductive wire 21 is are substantially identical to each other. In particular, the current extraction end portions 35 are provided at substantially even positions in the negative electrode current extraction layer 10 . As a result, the current to be supplied to the negative electrode current collector 51 can be more evenly supplied among the plurality of current extraction end portions 35 , and a plurality of current extraction end portions 35 are connected to the current extraction end portions 35 . , the current can be dispersedly distributed to the negative electrode conductor 21, thereby eliminating the occurrence of a portion where a large amount of current flows locally. At this time, the negative electrode-side current extraction layer 10 is divided into a plurality of regions 31 that are substantially equal to each other, and each current extraction end portion 35 is provided substantially at the center of each region 31, so that the negative electrode current collector 51 It becomes possible to more evenly supply the current to be supplied to between the plurality of current extraction end portions 35 .

In the present invention, it suffices that at least the positive electrode side or the negative electrode side exhibits the operation based on the above-described mechanism, and it is essential that both the positive electrode side and the negative electrode side always exhibit the operation based on the above-described mechanism. does not become Therefore, the configuration of the current extraction end 36, the positive electrode conductive wire 22, and the positive electrode junction 26 in the positive electrode current extraction layer 16 described above, the current extraction end 35 in the negative electrode current extraction layer 10, the negative electrode conductive wire 21, The configuration of the negative junction part 25 may be provided only on the side that produces the above-described operation, and may be omitted on the side that does not produce the operation.

It should be noted that the present invention is not limited to the modified examples described above. As shown in FIG. 18, in the current take-out portion 6 corresponding to each section, a plurality of current take-out units 61 each including a current take-out end portion 36, a plurality of positive electrode conductive wires 22, and a positive electrode junction portion 26 are provided. can be In such a case, a plurality of current extraction units 61 may be arranged on the positive electrode side current extraction layer 16 in one battery cell 40 . FIG. 19 shows an example of configuring a secondary battery module by arranging a plurality of battery cells 40 in parallel. The example of FIG. 19 is an example in which four battery cells 40 arranged in parallel share a common positive electrode junction portion 26 . The positive electrode side current extraction layer 16 in each battery cell 40 is provided with one current extraction end 36 . Similarly, positive electrode conductors 22a to 22d are extended to the positive electrode confluence portion 26 from respective current extraction end portions 36a to 36d of the four battery cells 40 sharing one positive electrode confluence portion 26. FIG. The electric resistances of the positive electrode conductors 22a to 22d are substantially the same.

　In the examples of Figs. 18 and 19, a positive electrode overall merging portion 72 is separately provided. The positive electrode general junction portion 72 is a portion for collecting the current taken out by each positive electrode junction portion 26 at one place. Each positive electrode junction 26 is electrically connected to the overall positive electrode junction 72 by a unit positive electrode conductor wire 92 . The unit positive electrode conductor wire 92 is similar in material and the like to the positive electrode conductor wire 22 , and has one end connected to the positive electrode junction portion 26 and the other end connected to the positive electrode overall junction portion 72 .

At this time, the lengths of the unit positive electrode conductors 92 are substantially the same. Since the positions of the positive electrode junctions 26 with respect to the overall positive electrode junction 72 are various, in order to make the lengths of the unit positive electrode conductive wires 92 approximately the same, the wires are intentionally detoured or reciprocated in a certain area. It will be adjusted by, for example, making a conductor shape that allows

In this manner, a plurality of unit positive electrode conductor wires 92 are provided for electrically connecting from the positive electrode junction 26 to the positive electrode overall junction portion 72, and the lengths of the unit positive electrode conductor wires 92 are substantially the same. It is said that As a result, the current to be taken out from the positive electrode current collector 55 can be taken out more evenly between the plurality of positive electrode junction portions 26, and the current can be dispersed and flowed to the plurality of unit positive electrode conductive wires 92. This eliminates the occurrence of a portion where a large amount of current locally flows. As a result, since the current distribution can be made uniform, the deterioration of the battery cell 40 itself can be suppressed, and the life of the battery cell 40 can be extended.

At this time, as long as the electrical resistance from the positive electrode joining portion 26 of each unit positive electrode conductive wire 92 to the positive electrode overall joining portion 72 is substantially the same, the materials, lengths, and diameters may be different from each other. . It is preferable that the electrical resistances are approximately equal to each other if they are 20% or less, and more preferably 10% or less or 5% or less.

In the above description, the unit positive electrode conductive wire 92 starts at the positive electrode junction 26 and ends at the overall positive electrode junction 72, but is not limited to this.

As shown in FIG. 13B , in the case where the positive electrode merging portion 26 is not provided, each unit positive electrode conductive wire 92 is also served by at least one lead wire 8 extending from one current extraction end portion 36 . may
In such a case, the unit positive electrode conductor wire 92, which also serves as the lead wire 8, should have substantially the same electrical resistance from the current extracting end portion 36 to the entire positive electrode confluence portion 72. As shown in FIG.

The same applies to the negative electrode, and a negative electrode general junction (not shown) corresponding to the positive electrode general junction 72 in FIG. 18 may be separately provided. This overall negative electrode junction portion (not shown) is a portion for collecting the current to be supplied from each of the plurality of negative electrode junction portions 25 at one point. Each negative electrode junction 25 is electrically connected to the entire negative electrode junction (not shown) by a unit negative electrode conductive line (not shown) corresponding to the unit positive electrode conductive line 92 . As a result, the current distribution can be made uniform even on the negative electrode side, so deterioration of the battery cell 40 itself can be suppressed, and the life of the battery cell 40 can be extended.

Similarly, for the negative electrode, as shown in FIG. 19, a secondary battery module may be configured by arranging a plurality of battery cells 40 in parallel. In such a case, the four battery cells 40 arranged in parallel may share the common negative electrode junction 25 . The negative current extraction layer 10 in each battery cell 40 is provided with one current extraction end 35 . Negative electrode conductive lines 21 a to 21 d are similarly extended to the negative electrode junction 25 from the respective current extraction end portions 35 a to 35 d of the four battery cells 40 sharing one negative electrode junction 25 . The lengths of the negative electrode conductors 21a to 21d are substantially the same.

In the modified example described above, the lengths of the unit negative electrode conductor wires (not shown) corresponding to the unit positive electrode conductor wires 92 from the negative electrode junction portion 25 to the negative electrode general junction portion (not shown) corresponding to the positive electrode general junction portion 72 are different from each other. Substantially the same is an example in which each unit negative electrode conductive wire (not shown) is made of the same material and has the same diameter. As a result, the electrical resistance between the unit negative electrode conductive lines (not shown) becomes substantially the same.

At this time, as long as the electrical resistance from the positive electrode joining portion 26 of each unit negative electrode conductive wire (not shown) to the positive electrode overall joining portion 72 is substantially the same, even if the materials, lengths, and diameters are different from each other. good.

In addition, as shown in FIG. 15B, in the case of an example in which the negative electrode joining portion 25 is not provided, each lead wiring 7 also serves as a unit negative electrode conductive line (not shown). As long as the electrical resistance up to the overall confluence portion 72 is substantially the same, the materials, lengths, and diameters may be different from each other. As shown in FIG. 15B, when the negative electrode confluence portion 25 is not formed, at least one lead wire 7 extending from one current extraction end portion 35 also serves as each unit negative electrode conductive line (not shown). good too. In such a case, if the electric resistance of the unit negative electrode conductive wire (not shown), which also serves as the lead wire 7, from the current extraction end portion 35 to the negative electrode general junction (not shown) corresponding to the positive electrode general junction 72 is substantially the same. Just do it.

In the modified example described above, it was explained that local concentration of current can be suppressed by equalizing the resistances of the negative electrode current extraction layer 10 and the positive electrode current extraction layer 16 during discharge. The same is true of time. During charging, the directions of the currents are all reversed, and the mechanism for equalizing the resistances of the negative current extraction layer 10 and the positive current extraction layer 16 is the same as during discharging. Therefore, according to the present invention, local current concentration can be suppressed not only during discharging but also during charging, and the life of the battery can be further extended.

20A and 20B, when the positive electrode-side current extraction layer 16 is made of a material in which a small hole 96 penetrating from the upper end to the lower end is formed, the following effects can be obtained. Become. If air bubbles 81 are formed between the positive electrode current extraction layer 16 and the positive electrode current collector 55 during manufacturing, the air bubbles 81 pass through the small holes 96 and are released to the outside by placing in a reduced pressure environment. By doing so, it becomes possible to remove this.

By removing the air bubbles 81 in this way, the adhesion between the positive current collector 55 and the positive current extraction layer 16 is improved. By similarly forming the small holes 96 in the negative electrode-side current extraction layer 10 as well, it is possible to improve the adhesion by removing the air bubbles 81 in the same manner.

A secondary battery module according to an embodiment of the present invention includes
an assembled battery in which a plurality of single cells are stacked;
a first optical communication unit provided in each of the plurality of cells;
a control device provided in the plurality of cells and controlling the first optical communication unit;
an external control device that controls each of the plurality of cells;
a second optical communication unit provided in the external control device;
an optical waveguide provided between the first optical communication unit and the second optical communication unit,
The first optical communication unit and the second optical communication unit are configured to perform two-way communication via the optical waveguide,
The external control device is configured to operate as a master that manages the control device as a slave.

In the secondary battery module according to the above embodiment, the two-way communication is half-duplex communication.

In the secondary battery module according to the above embodiment,
Each of the first optical communication units
having a unique light emission timing and a unique light reception timing,
receiving an optical signal by receiving light from the optical waveguide at the unique light receiving timing;
On the condition that the received optical signal matches a predetermined code, the optical signal is transmitted by emitting light to the optical waveguide at the unique light emission timing.

In the secondary battery module according to the above embodiment,
The second optical communication unit is
having variable light emission timing and variable light reception timing,
transmitting the predetermined code by radiating light to the optical waveguide by matching the variable light emission timing with the unique light reception timing of the first optical communication unit;
An optical signal is received by receiving the light from the optical waveguide by matching the variable light receiving timing with the unique light emitting timing of the first optical communication unit.

In the secondary battery module according to the above embodiment,
The second optical communication unit, for each of the plurality of cells,
transmitting the predetermined code by sequentially changing the variable light emission timing and emitting light to the optical waveguide;
receiving an optical signal by receiving light from the optical waveguide by matching the variable light receiving timing with the variable light emitting timing at which the predetermined code is transmitted;
The variable light emission timing at which the predetermined code is transmitted is the first optical communication on condition that the optical signal is received at the variable light reception timing that coincides with the variable light emission timing at which the predetermined code is transmitted. It is further configured to determine that it is the unique light receiving timing of the part.

In the secondary battery module according to the above embodiment,
The second optical communication unit has a storage unit,
The second optical communication unit is further configured to store the determined specific light receiving timing of the first optical communication unit in the storage unit.

In the secondary battery module according to the above embodiment,
the predetermined code includes a setting code for setting the specific light emission timing and the specific light reception timing of the first optical communication unit;
Each of the first optical communication units
The specific light emission timing and the specific light reception of the first optical communication unit based on the setting code included in the predetermined code on condition that the received optical signal matches the predetermined code. It is further configured to set the timing.

In the secondary battery module according to the above embodiment, the setting code is a reset code.

In the secondary battery module according to the above embodiment, the setting code indicates the offset of the unique light emission timing and the unique light reception timing.

In the secondary battery module according to the above embodiment,
each of the first optical communication units has a unique identification code;
The predetermined code includes the unique identification code.

In the secondary battery module according to the above embodiment, the predetermined code includes an error detection code.

In the secondary battery module according to the above embodiment, the unit cell corresponding to the first optical communication unit is used as a power source.

In the secondary battery module according to the above embodiment,
A current extraction layer is in contact with at least one surface of the outermost layer in the assembled battery,
the current extraction layer has a current extraction part through which current flows from the laminated battery,
The current extraction portion is divided into a plurality of sections in the current extraction layer, and each section has an independent current extraction line.

In the secondary battery module according to the above embodiment, the current extraction portion is divided into 4 or more and 50 or less sections in the current extraction layer.

In the secondary battery module according to the above embodiment, the compartments are provided in substantially uniform shapes and positions in the current extraction layer.

In the secondary battery module according to the above embodiment,
the current extraction layer is divided into a plurality of regions having substantially equal top surfaces;
Each of the current extraction portions is provided substantially at the center of each of the regions.

In the secondary battery module according to the above embodiment,
a plurality of current extraction units including one or more current extraction ends;
A unit electrode conductive wire for electrically connecting the current take-out end portion to the entire electrode confluence portion is provided for each current take-out unit,
The electric resistance of each unit electrode conductive line is substantially the same.

In the secondary battery module according to the above embodiment,
The current extraction line has a plurality of current extraction end portions and a plurality of electrode conductive wires for electrically connecting the current extraction end portions to the electrode confluence portion,
The electrical resistance of each electrode conductive line is substantially the same.

In the secondary battery module according to the above embodiment,
The current extraction layer is made of a flexible printed circuit board,
The flexible printed circuit board is a double-sided board.

In the secondary battery module according to the above embodiment,
The current extraction layer is made of a flexible printed circuit board,
The flexible printed circuit board is provided on the positive electrode side and the negative electrode side of the laminated battery,
The current take-out portion is divided into a plurality of sections on the flexible printed circuit board, and each section has an independent current take-out line.

The method for controlling the secondary battery module according to the above embodiment includes:
an assembled battery in which a plurality of unit cells are stacked; a first optical communication unit provided in each of the plurality of unit cells; and a first optical communication unit provided in the plurality of unit cells to control the first optical communication unit. a control device, an external control device for controlling each of the plurality of cells, a second optical communication unit provided in the external control device, the first optical communication unit and the second optical communication unit and an optical waveguide provided between, wherein the first optical communication unit and the second optical communication unit are configured to perform two-way communication via the optical waveguide, and the external control device is a control method executed in a secondary battery module configured to operate as a master that manages the control device as a slave,
Each of the first optical communication units has a unique light emission timing and a unique light reception timing, the second optical communication unit has a variable light emission timing and a variable light reception timing,
The control method is
the second optical communication unit transmitting a predetermined code by radiating light to the optical waveguide with the variable light emission timing matching the unique light reception timing of the first optical communication unit;
Each of the first optical communication units receives an optical signal by receiving light from the optical waveguide at the unique light receiving timing;
Each of the first optical communication units transmits an optical signal by emitting light to the optical waveguide at the unique light emission timing on condition that the received optical signal matches the predetermined code. and
The second optical communication unit receives an optical signal by receiving light from the optical waveguide with the variable light receiving timing matching the unique light emission timing of the first optical communication unit. include.

According to the aspect described above, it is possible to transmit and receive optical signals from each of the plurality of single cells constituting the assembled battery without overlapping on the optical waveguide at an arbitrary timing, which is industrial applicability. high secondary battery module can be provided.

Claims

an assembled battery in which a plurality of single cells are stacked;
a first optical communication unit provided in each of the plurality of cells;
a control device provided in the plurality of cells and controlling the first optical communication unit;
an external control device that controls each of the plurality of cells;
a second optical communication unit provided in the external control device;
an optical waveguide provided between the first optical communication unit and the second optical communication unit,
The first optical communication unit and the second optical communication unit are configured to perform two-way communication via the optical waveguide,
A secondary battery module, wherein the external control device is configured to operate as a master that manages the control device as a slave.
The secondary battery module according to claim 1, wherein said two-way communication is half-duplex communication.
Each of the first optical communication units
having a unique light emission timing and a unique light reception timing,
receiving an optical signal by receiving light from the optical waveguide at the unique light receiving timing;
3. The apparatus according to claim 1, wherein, on condition that the received optical signal matches a predetermined code, the optical signal is transmitted by emitting light to the optical waveguide at the unique light emission timing. secondary battery module.
The second optical communication unit is
having variable light emission timing and variable light reception timing,
transmitting the predetermined code by radiating light to the optical waveguide by matching the variable light emission timing with the unique light reception timing of the first optical communication unit;
4. The device according to claim 3, wherein an optical signal is received by receiving light from said optical waveguide with said variable light receiving timing matching said unique light emitting timing of said first optical communication unit. Secondary battery module.
The second optical communication unit, for each of the plurality of cells,
transmitting the predetermined code by sequentially changing the variable light emission timing and emitting light to the optical waveguide;
receiving an optical signal by receiving light from the optical waveguide by matching the variable light receiving timing with the variable light emitting timing at which the predetermined code is transmitted;
The variable light emission timing at which the predetermined code is transmitted is the first optical communication on condition that the optical signal is received at the variable light reception timing that coincides with the variable light emission timing at which the predetermined code is transmitted. 5. The secondary battery module of claim 4, further configured to determine that it is the unique light receiving timing of a part.
The second optical communication unit has a storage unit,
6. The secondary battery module according to claim 5, wherein said second optical communication unit is further configured to store said determined specific light receiving timing of said first optical communication unit in said storage unit.
the predetermined code includes a setting code for setting the specific light emission timing and the specific light reception timing of the first optical communication unit;
Each of the first optical communication units
The specific light emission timing and the specific light reception of the first optical communication unit based on the setting code included in the predetermined code on condition that the received optical signal matches the predetermined code. 4. The secondary battery module of claim 3, further configured to set timing.
The secondary battery module according to claim 7, wherein said setting code is a reset code.
The secondary battery module according to claim 7, wherein said setting code indicates an offset of said unique light emission timing and said unique light reception timing.
each of the first optical communication units has a unique identification code;
The secondary battery module according to any one of claims 3 to 9, wherein said predetermined code includes said unique identification code.
The secondary battery module according to claim 10, wherein said predetermined code includes an error detection code.
The secondary battery module according to any one of claims 1 to 11, wherein the unit battery corresponding to the first optical communication unit is used as a power supply.
A current extraction layer is in contact with at least one surface of the outermost layer in the assembled battery,
the current extraction layer has a current extraction part through which current flows from the laminated battery,
wherein the current extraction portion is divided into a plurality of sections in the current extraction layer, and each section has an independent current extraction line;
The secondary battery module according to any one of claims 1-12.
The secondary battery module according to claim 13, wherein the current extraction portion is divided into 4 or more and 50 or less sections in the current extraction layer.
15. The secondary battery module according to claim 14, wherein the partitions are provided in substantially uniform shapes and positions in the current extraction layer.
the current extraction layer is divided into a plurality of regions having substantially equal top surfaces;
16. The secondary battery module according to claim 15, wherein each current extraction portion is provided substantially at the center of each region.
A plurality of current extraction units including one or more current extraction ends,
A unit electrode conductive wire for electrically connecting the current take-out end portion to the entire electrode confluence portion is provided for each current take-out unit,
The secondary battery module according to any one of claims 13 to 16, wherein electrical resistances of the unit electrode conductive lines are substantially the same.
The current extraction line has a plurality of current extraction ends and a plurality of electrode conductive wires for electrically connecting the current extraction ends to the electrode confluence,
The secondary battery module according to any one of claims 13 to 17, wherein electrical resistances of the respective electrode conductive lines are substantially the same.
The current extraction layer is made of a flexible printed circuit board,
The flexible printed circuit board is a double-sided board,
The secondary battery module according to any one of claims 13-18.
The current extraction layer is made of a flexible printed circuit board,
The flexible printed circuit board is provided on the positive electrode side and the negative electrode side of the laminated battery,
wherein the current extraction part is divided into a plurality of sections on the flexible printed circuit board, and each section has an independent current extraction line;
The secondary battery module according to any one of claims 13-19.
an assembled battery in which a plurality of unit cells are stacked; a first optical communication unit provided in each of the plurality of unit cells; and a first optical communication unit provided in the plurality of unit cells to control the first optical communication unit. a control device, an external control device for controlling each of the plurality of cells, a second optical communication unit provided in the external control device, the first optical communication unit and the second optical communication unit and an optical waveguide provided between, wherein the first optical communication unit and the second optical communication unit are configured to perform two-way communication via the optical waveguide, and the external control device is a control method executed in a secondary battery module configured to operate as a master that manages the control device as a slave,
Each of the first optical communication units has a unique light emission timing and a unique light reception timing, the second optical communication unit has a variable light emission timing and a variable light reception timing,
The control method is
the second optical communication unit transmitting a predetermined code by radiating light to the optical waveguide with the variable light emission timing matching the unique light reception timing of the first optical communication unit;
Each of the first optical communication units receives an optical signal by receiving light from the optical waveguide at the unique light receiving timing;
Each of the first optical communication units transmits an optical signal by emitting light to the optical waveguide at the unique light emission timing on condition that the received optical signal matches the predetermined code. and
The second optical communication unit receives an optical signal by receiving light from the optical waveguide with the variable light receiving timing matching the unique light emission timing of the first optical communication unit. A control method for a secondary battery module, comprising: