Secondary batteries

Abstract

This technology provides a way to quickly and uniformly control the temperature inside a secondary battery. [Solution] A secondary battery comprising a cell case for housing electrodes and an electrolyte, a sealing body for surrounding and sealing the electrodes and electrolyte within the cell case, and a flow hole that reaches a flow region formed between the inner surface of the cell case and the sealing body from the outside of the cell case. The sealing body extends from the sealing region for sealing the electrolyte to the outside of the cell case and has a retractable portion that allows a portion of the electrolyte to be taken in and out of the sealing region. As the sealing region is pressed by a temperature-regulating substance supplied to the flow region, a portion of the electrolyte is pushed out of the sealing region to the retractable portion, while as the temperature-regulating substance is recovered from the flow region and the sealing region expands, the electrolyte is returned from the retractable portion to the sealing region.

Description

Technical Field

[0001] The present disclosure relates to secondary batteries.

Background Art

[0002] Conventionally, in a secondary battery system including a secondary battery, it is common to configure the secondary battery to be temperature controllable. This is because when the secondary battery reaches a temperature above or below a certain level, a predetermined output cannot be stably obtained. As a configuration for making the secondary battery temperature controllable, for example, a configuration has been proposed in which the secondary battery is temperature controlled by a cooler disposed outside the cell case of the secondary battery (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described configuration, there is a problem that it is difficult to quickly and uniformly temperature control the inside of the secondary battery (for example, electrolyte, electrodes, etc.) because the temperature of the secondary battery is controlled from the outside of the cell case.

[0005] The present disclosure has been made to solve such problems, and an object thereof is to provide a technique for quickly and uniformly temperature controlling the inside of a secondary battery.

Means for Solving the Problems

[0006] The secondary battery according to the present disclosure includes a cell case that houses electrodes and an electrolyte, a sealing body that seals and surrounds the electrodes and the electrolyte within the cell case, and a circulation hole that reaches a circulation region formed between the inner peripheral surface of the cell case and the sealing body from the outside of the cell case. [Effects of the Invention]

[0007] In the secondary battery disclosed above, the electrodes and electrolyte are housed in a cell case while sealed in a encapsulant, and a flow region is formed between the inner circumferential surface of the cell case and the encapsulant.

[0008] With such a secondary battery, the temperature control substance can be circulated into the cell case through the flow holes, allowing for direct temperature control inside the battery. As a result, rapid and uniform temperature control can be achieved inside the battery. [Brief explanation of the drawing]

[0009] [Figure 1] Block diagram of a secondary battery system according to the first embodiment of this disclosure [Figure 2] Perspective view of a secondary battery according to the first embodiment of this disclosure [Figure 3] Enlarged view of the main part of a secondary battery according to the first embodiment of this disclosure [Figure 4] Perspective view of a secondary battery according to the first embodiment of this disclosure (process of supplying temperature-regulating substance (a), process of recovering temperature-regulating substance (b)) [Figure 5] Block diagram of a secondary battery system according to the second embodiment of this disclosure. [Figure 6] Perspective view of a secondary battery according to the second embodiment of this disclosure [Figure 7] Enlarged view of the main part of a secondary battery according to the second embodiment of this disclosure [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings. (1) First Embodiment

[0011] (1-1) Overall structure As shown in Figure 1, the secondary battery system 1 comprises a plurality of secondary batteries 100, a storage unit 10 for storing a temperature-controlled substance 200, a flow passage 20 connecting each secondary battery 100 to the storage unit 10, a pump unit 30 for circulating the temperature-controlled substance 200 through the flow passage 20, a plurality of measuring units 40 for measuring the temperature of each secondary battery 100, a temperature control unit 50 for controlling the temperature of the temperature-controlled substance 200, and a control unit 70 for controlling the operation of the entire secondary battery system 1. In this embodiment, the secondary battery system 1 is exemplified as being installed in a vehicle such as an electric vehicle or a hybrid vehicle (including plug-in hybrid vehicles (PHEVs) that enable external charging and external power supply).

[0012] As shown in Figures 2 and 3, the secondary battery 100 comprises a cell case 120 that houses a pair of electrodes 111 and an electrolyte 113, a sheet-like sealant 130 that surrounds and seals the electrodes 111 and the electrolyte 113 within the cell case 120, and a flow hole 140 that penetrates the cell case 120 inward and outward. This flow hole 140 reaches a flow region 121 formed between the inner circumferential surface of the cell case 120 and the sealant 130 from the outside of the cell case 120.

[0013] Here, the secondary battery 100 consists of a winding body 110, which is made by winding stacked sheet-like electrodes 111 and a separator (not shown), within a cell case 120. This winding body 110 is impregnated with a liquid electrolyte 113 inside a sealing body 130. Of these, one end of each pair of electrodes 111 extends outside the cell case 120. A gel-like electrolyte 113 may also be used.

[0014] Among these, the sealing body 130 extends from a sealing region 131 that seals the electrolyte 113 to the outside of the cell case 120, and has a retreat portion 133 that can take in and out a part of the electrolyte 113 from the sealing region 131. In the sealing region 131 of the present embodiment, an electrolyte 113 having a total capacity greater than or equal to the sum of a first capacity that is the minimum required to function as the secondary battery 100 at least and a second capacity that is the maximum capacity that can be accommodated in the retreat portion 133 is sealed. In the present embodiment, an electrolyte 113 having a capacity corresponding to this total capacity is sealed.

[0015] As shown in FIG. 4(a), when the sealing region 131 is pressed by the temperature control substance 200 supplied to the flow region 121, a part of the electrolyte 113 is pushed out from the sealing region 131 to the retreat portion 133 in this sealing body 130. At this time, the retreat portion 133 expands until the electrolyte 113 pushed out from the sealing region 131 reaches the second capacity. The sealing region 131 is in a state where the electrolyte 113 having the maximum second capacity is pushed out to the retreat portion 133, but the electrolyte 113 is not pushed out to the retreat portion 133 until it falls below the first capacity.

[0016] On the other hand, as shown in FIG. 4(b), when the temperature control substance 200 is recovered from the flow region 121 and the sealing region 131 expands, the electrolyte 113 is returned from the retreat portion 133 to the sealing region 131 in the sealing body 130. At this time, the retreat portion 133 contracts so as to return the electrolyte 113 to the sealing region 131.

[0017] Thereby, according to the capacity of the temperature control substance 200 flowing in the flow region 121, the retreat portion 133 of the sealing body 130 is deformed between an initial state (see FIG. 4(b)) in which the retreat portion 133 does not contain the electrolyte 113 and a retreat state (see FIG. 4(a)) in which the retreat portion 133 contains the electrolyte 113 having the second capacity.

[0018] The storage unit 10 stores the temperature control substance 200 within a predetermined storage space. The temperature control substance 200 in the present embodiment is a liquid medium suitable for temperature control of the secondary battery 100. The temperature control substance 200 stored in this storage unit 10 corresponds to a capacity equal to the sum of the second capacity and the third capacity, which is the maximum capacity of the temperature control substance 200 flowing through the flow path 20 (a capacity corresponding to the number of secondary batteries 100).

[0019] One end side of the flow path 20 is connected to each of the flow holes 140 of the cell case 120, and the other end side is connected to the storage unit 10, allowing the temperature control substance 200 to flow between the secondary battery 100 and the storage unit 10.

[0020] The pump unit 30 receives a command from the control unit 70 and circulates the temperature control substance 200 stored in the storage unit 10 into the flow path 20.

[0021] The measurement unit 40 is provided on each of the cell cases 120 of the secondary battery 100 and is a temperature sensor that measures the temperature inside the secondary battery 100.

[0022] The temperature control unit 50 is provided in the flow path 20 and controls the temperature of the temperature control substance 200 flowing through the flow path 20. In the present embodiment, a heater for heating (more specifically, a PTC (Positive Temperature Coefficient) heater) and a radiator for cooling are adopted as the temperature control unit 50. Note that the temperature control unit 50 may be provided in the storage unit 10 and configured to control the temperature of the temperature control substance 200 stored therein.

[0023] The control unit 70 is a battery management system that controls the operation of the entire secondary battery system 1 by executing various processes according to a program stored in a built-in memory.

[0024] The control unit 70 controls the temperature control unit 50 so that the temperature control substance 200 flowing through the flow passage 20 falls within a predetermined target temperature range T0. Furthermore, if the temperature measured by the measurement unit 40 is outside the target temperature range T0, the control unit 70 controls the pump unit 30 so that the temperature control substance 200 stored in the storage unit 10 is supplied to the cell case 120 via the flow passage 20. Here, the pump unit 30 is controlled only for the time necessary for all of the temperature control substance 200 stored in the storage unit 10 (i.e., the total capacity of the second and third capacities) to be supplied to the cell case 120.

[0025] Subsequently, the control unit 70 controls the pump unit 30 so that the temperature-controlled substance 200 circulating in the cell case 120 is recovered to the storage unit 10 via the flow passage 20 after the temperature measured by the measurement unit 40 falls within the target temperature range T0. Here, the pump unit 30 is controlled for only the time necessary for all (i.e., the second volume) of the temperature-controlled substance 200 circulating in the cell case 120 to be recovered to the storage unit 10.

[0026] (1-2) Effects In the secondary battery 100 of the above embodiment, the electrodes 111 and electrolyte 113 are housed in the cell case 120 with the electrodes 111 and electrolyte 113 sealed in the sealant 130, and a flow region 121 is formed between the inner surface of the cell case 120 and the sealant 130.

[0027] With such a secondary battery 100, the temperature control substance 200 can be circulated into the cell case 120 via the flow holes 140, thereby directly controlling the temperature inside the secondary battery 100 and achieving rapid and uniform temperature control inside.

[0028] Furthermore, in the secondary battery 100 of the above embodiment, the encapsulant 130 has a retracted portion 133 that extends from the encapsulating region 131 to the outside of the cell case 120, and is configured so that a part of the electrolyte 113 in the encapsulating region 131 is moved in and out between the encapsulant 130 and the retracted portion 133.

[0029] In this way, by pushing a portion of the electrolyte 113 into the retraction section 133 and allowing more of the temperature-controlling substance 200 to circulate in the circulation area 121, the temperature inside the secondary battery 100 can be effectively controlled.

[0030] Furthermore, in the secondary battery 100 of the above embodiment, the retractable portion 133 is configured to expand until the electrolyte 113 pushed out from the sealing region 131 reaches a second capacity, and the state in which the electrolyte 113 is pushed out into the retractable portion 133 until the sealing region 131 falls below the first capacity is avoided.

[0031] Therefore, even if a portion of the electrolyte 113 sealed in the sealing region 131 is pushed out into the retracted portion 133, the electrolyte will not fall below the minimum first capacity required for the secondary battery 100 to function. As a result, the secondary battery 100 of the above embodiment can maintain its function as a secondary battery while controlling the temperature inside.

[0032] (2) Second Embodiment (2-1) Overall structure As shown in Figure 5, the secondary battery system 1 of this embodiment, similar to the first embodiment, comprises a plurality of secondary batteries 100, a storage unit 10, a flow passage 20, a pump unit 30, a plurality of measuring units 40, a temperature control unit 50, and a control unit 70, and also includes a recovery path 60 that connects the secondary batteries 100 and the storage unit 10 via a route separate from the flow passage 20.

[0033] As shown in Figures 6 and 7, the secondary battery 100 of this embodiment includes a cell case 120, a sealant 130, and a flow-through hole 140, similar to the first embodiment. The flow-through hole 140 consists of a first flow-through hole 141 for supplying a temperature-controlling substance 200 from outside the cell case 120 to the flow-through region 121, and a second flow-through hole 143 for discharging the temperature-controlling substance 200 from the flow-through region 121 to outside the cell case 120. The sealant 130 may be made of a material other than a sheet-like member.

[0034] The recovery path 60 is connected at one end to each of the second flow holes 143 of the cell case 120 and at the other end to the storage section 10, allowing the temperature control substance 200 to flow between the secondary battery 100 and the storage section 10.

[0035] The control unit 70 controls the pump unit 30 so that the temperature-controlled substance 200 is supplied from the flow passage 20 into the cell case 120 when the temperature measured by the measurement unit 40 is outside the target temperature range T0. The control unit 70 also controls the temperature control unit 50 so that the temperature-controlled substance 200 flowing through the flow passage 20 is within the target temperature range T0.

[0036] (2-2) Effects In the secondary battery 100 of the above embodiment, a temperature-controlling substance 200 is supplied from the outside to the circulation area 121 inside the cell case 120 through the first circulation hole 141, directly regulating the temperature inside the secondary battery 100, and then the temperature-controlling substance 200 can be discharged from the second circulation hole 143. By circulating the temperature-controlling substance 200 inside and outside the cell case 120 in this way, the temperature inside the secondary battery 100 can be effectively regulated. [Explanation of symbols]

[0037] 1...Secondary battery system, 10...Storage section, 20...Flow passage, 30...Pump section, 40...Measurement section, 50...Temperature control section, 60...Recovery path, 70...Control section, 100...Secondary battery, 110...Winding body, 111...Electrode, 113...Electrolyte, 120...Cell case, 121...Flow area, 130...Sealing body, 131...Sealing area, 133...Retraction section, 140...Flow hole, 141...First flow hole, 143...Second flow hole, 200...Temperature control substance.

Claims

1. A cell case for housing electrodes and electrolytes, A sealing body that surrounds and seals the electrode and electrolyte within the cell case, The cell case is provided with a flow hole that reaches a flow region formed between the inner surface of the cell case and the sealing body from the outside of the cell case. Secondary battery.

2. The aforementioned encapsulant is It has a retractable portion that extends from the sealing region that seals the electrolyte to the outside of the cell case, and from the sealing region a portion of the electrolyte can be inserted into or removed from the sealing region. As the sealing region is pressed by the temperature-regulating substance supplied to the flow region, a portion of the electrolyte is pushed out from the sealing region to the retraction section. Conversely, as the temperature-regulating substance is recovered from the flow region and the sealing region expands, the electrolyte is returned from the retraction section to the sealing region. The secondary battery according to claim 1.

3. The sealed region seals an electrolyte with a capacity at least equal to the sum of a first capacity and a predetermined second capacity, which is the minimum capacity required to function as a secondary battery. The retracted portion expands as the sealing region is pressed by the temperature-regulating substance supplied to the flow region, causing the electrolyte to be pushed out from the sealing region to reach the second volume, while contracting to return the electrolyte to the sealing region as the temperature-regulating substance is recovered from the flow region and the sealing region expands. The secondary battery according to claim 2.

4. The flow hole comprises a first flow hole for supplying a temperature-controlling substance from outside the cell case to the flow area, and a second flow hole for discharging the temperature-controlling substance from the flow area to outside the cell case. The secondary battery according to claim 1.

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