Secondary battery system

Abstract

This technology provides a way to quickly and uniformly control the temperature inside a secondary battery. [Solution] A secondary battery system comprising: a cell case for housing electrodes and an electrolyte; a sheet-like sealing body for surrounding and sealing the electrodes and electrolyte within the cell case; 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; a storage section for storing a temperature-controlling substance; a flow passage having one end connected to the flow hole of the cell case and the other end connected to the storage section; and a pump section for circulating the temperature-controlling substance stored in the storage section into the flow passage.

Description

Technical Field

[0001] The present disclosure relates to a secondary battery system including a secondary battery.

Background Art

[0002] Conventionally, in a secondary battery system including a secondary battery, it is common to configure the secondary battery to be temperature-adjustable. This is because when the secondary battery reaches a temperature above a certain level or below a certain level, a predetermined output cannot be obtained stably. As a configuration for making the secondary battery temperature-adjustable, for example, a configuration in which the secondary battery is temperature-adjusted by a cooler disposed outside the cell case of the secondary battery has been proposed (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-adjust the inside of the secondary battery (for example, electrolyte, electrodes, etc.) because the secondary battery is temperature-adjusted 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 enabling quick and uniform temperature adjustment up to the inside of the secondary battery.

Means for Solving the Problems

[0006] The secondary battery system according to this disclosure comprises a cell case for housing electrodes and an electrolyte, a sheet-like sealant that surrounds and seals the electrodes and electrolyte within the cell case, a flow hole that reaches a flow region formed between the inner surface of the cell case and the sealant from outside the cell case, a storage section for storing a temperature-controlling substance, a flow passage having one end connected to the flow hole of the cell case and the other end connected to the storage section, and a pump section for circulating the temperature-controlling substance stored in the storage section into the flow passage. [Effects of the Invention]

[0007] In the secondary battery system described above, the pump section is controlled, and the temperature-controlled substance stored in the storage section is circulated through the flow passage into the cell case of the secondary battery. This allows for direct temperature control inside the secondary battery, thus enabling rapid and uniform temperature control within the battery. [Brief explanation of the drawing]

[0008] [Figure 1] Block diagram of a secondary battery system according to one embodiment of the present disclosure. [Figure 2] Perspective view of a secondary battery according to one embodiment of the present disclosure [Figure 3] Enlarged view of a key part of a secondary battery according to one embodiment of the present disclosure [Figure 4] Perspective view of a secondary battery according to one embodiment of the present disclosure (process of supplying temperature-regulating substance (a), process of recovering temperature-regulating substance (b)) [Figure 5] Flowchart showing temperature control processing according to one embodiment of this disclosure [Modes for carrying out the invention]

[0009] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings.

[0010] (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).

[0011] 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.

[0012] 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.

[0013] Of these, the sealing body 130 extends from the sealing region 131 that seals the electrolyte 113 to the outside of the cell case 120 and has a retractable portion 133 that allows a portion of the electrolyte 113 to be inserted into or removed from the sealing region 131. In this embodiment, the sealing region 131 contains an electrolyte 113 that is equal to or greater than the sum of a first capacity, which is the minimum capacity required to function as a secondary battery 100, and a second capacity, which is the maximum capacity that can be accommodated in the retractable portion 133. In this embodiment, an amount of electrolyte 113 equivalent to this total capacity is sealed.

[0014] As shown in Figure 4(a), when the sealing region 131 is pressed by the temperature-controlled substance 200 supplied to the flow region 121, a portion of the electrolyte 113 is pushed out of the sealing region 131 into the retraction region 133. At this time, the retraction region 133 expands until the amount of electrolyte 113 pushed out from the sealing region 131 reaches the second volume. The sealing region 131 will be in a state where up to the second volume of electrolyte 113 has been pushed out into the retraction region 133, but the amount of electrolyte 113 pushed out into the retraction region 133 will not fall below the first volume.

[0015] On the other hand, as shown in Figure 4(b), as the temperature-controlling substance 200 is recovered from the flow region 121 and the sealing region 131 expands, the electrolyte 113 is returned from the retracted portion 133 to the sealing region 131. At this time, the retracted portion 133 contracts to return the electrolyte 113 to the sealing region 131.

[0016] In this way, the sealing body 130 deforms between an initial state in which the retracted section 133 does not contain the electrolyte 113 (see Figure 4(b)) and a retracted state in which it contains a second volume of the electrolyte 113 (see Figure 4(a)), depending on the volume of the temperature-controlled substance 200 flowing in the flow area 121.

[0017] The storage unit 10 stores the temperature control substance 200 within a predetermined storage space. The temperature control substance 200 of 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 total capacity that is 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).

[0018] 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, and the temperature control substance 200 is circulated between the secondary battery 100 and the storage unit 10.

[0019] The pump unit 30 receives a command from the control unit 70 and circulates the temperature control substance 200 between the storage unit 10 and the flow path 20.

[0020] The measurement unit 40 is provided on each of the cell cases 120 in the secondary battery 100, and is a temperature sensor that measures the temperature inside the secondary battery 100.

[0021] The temperature control unit 50 is provided in the flow path 20 and controls the temperature of the temperature control substance 200 flowing in 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.

[0022] [[ID=第十九]]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.

[0023] (2) Temperature control process by the control unit Subsequently, the processing procedure of the temperature control process executed by the control unit 70 will be described based on FIG. 5. This temperature control process is activated upon receiving an activation command from an ECU mounted on the vehicle.

[0024] ​ When this temperature control process is activated, the system first enters a standby state until the temperature TB of the secondary battery 100 falls outside the predetermined target temperature range T0 (T0L~T0H) (TB≠T0) (S110:NO). Here, if any of the temperatures TB of the secondary battery 100 measured by each of the measurement units 40 are outside the target temperature range T0, it is determined that the temperature TB of the secondary battery 100 is outside the target temperature range T0. However, in S110, it is also possible to determine that the temperature TB of the secondary battery 100 is outside the target temperature range T0 if the average value of the temperatures TB measured by each of the measurement units 40 is outside the target temperature range T0.

[0025] The target temperature range T0 is predetermined as the temperature range suitable for the normal operation of the secondary battery 100.

[0026] In S110, if it is determined that the temperature TB of the secondary battery 100 is outside the target temperature range T0 (TB≠T0) (S110:YES), the supply of the temperature-controlled substance 200 into the cell case 120 is started (S120). Here, the control of the pump unit 30 is started so that the temperature-controlled substance 200 stored in the storage unit 10 is supplied into the cell case 120 via the flow passage 20. In this way, the supply of the temperature-controlled substance 200 into the cell case 120 is started (see Figure 4(a)). In this embodiment, the pump unit 30 is controlled only for the time necessary for all of the temperature-controlled 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. However, in S120, a capacity sensor may be provided in the storage unit 10, and the pump unit 30 may be controlled until it is detected that the remaining amount of temperature-controlled substance 200 has become zero or that the total capacity has been supplied.

[0027] Next, temperature control of the temperature-controlled substance 200 flowing in the flow passage 20 is started (S130). Here, the temperature control unit 50 is started to control the temperature-controlled substance 200 flowing in the flow passage 20 so that it reaches the set temperature. In this way, temperature control of the temperature-controlled substance 200 is started. In this embodiment, the set temperature is the temperature (T0H-Δt, T0L+Δt) that is shifted by a predetermined temperature Δt from one of the upper limit T0H and lower limit T0L in the target temperature range T0 to the other side, and the temperature control unit 50 controls the temperature-controlled area of ​​the flow passage 20 so that it reaches this set temperature. However, in S130, a temperature sensor may be provided in the temperature-controlled area, and the temperature control unit 50 may be feedback controlled so that this temperature reaches the set temperature.

[0028] Next, the system enters a standby state until the temperature-controlled substance 200 is filled into the secondary battery 100 (S140:NO). Here, it is determined that the temperature-controlled substance 200 has been filled into the secondary battery 100 when the time required for all of the temperature-controlled substance 200 (i.e., the total capacity of the second and third capacities) to be supplied from the storage unit 10 to the cell case 120 has elapsed since S120. However, in S140, it is also acceptable to determine that the temperature-controlled substance 200 has been filled into the secondary battery 100 when the control of the pump unit 30, which was started in S120, has been stopped.

[0029] Subsequently, if it is determined that the secondary battery 100 has been filled with the temperature-controlling substance 200 (S140: YES), the supply of the temperature-controlling substance 200, which was started in S120, is stopped (S150). Here, the supply of the temperature-controlling substance 200 is stopped by stopping the control of the pump unit 30.

[0030] Next, the temperature control of the temperature-controlled substance 200, which was started in S130, is stopped (S160). Here, the temperature control of the temperature-controlled substance 200 is stopped by stopping the control of the temperature control unit 50.

[0031] Next, the system enters a standby state until the temperature TB of the secondary battery 100 falls within the target temperature range T0 (TB=T0) (S170:NO). Here, it is determined whether or not the temperature TB of the secondary battery 100 is within the target temperature range T0 based on the temperature TB measured by each of the measurement units 40. However, in S170, it is also possible to determine that the temperature TB of the secondary battery 100 is within the target temperature range T0 after the time required (for example, a few seconds) has elapsed for the temperature-regulating substance 200 supplied into the secondary battery 100 to regulate the temperature inside the secondary battery 100.

[0032] In S170, if it is determined that the temperature TB of the secondary battery 100 is within the target temperature range T0 (S170: YES), the temperature-controlled substance 200 is recovered from the cell case 120 (S180). Here, the control of the pump unit 30 is started so that all of the temperature-controlled substance 200 circulating in the cell case 120 is recovered to the storage unit 10. Thus, the recovery of the temperature-controlled substance 200 from the cell case 120 begins (see Figure 4(b)). In this embodiment, the pump unit 30 is controlled for only the time necessary for all (i.e., the second capacity) of the temperature-controlled substance 200 circulating in the cell case 120 to be recovered to the storage unit 10. However, in S180, a capacity sensor may be provided in the cell case 120, and the pump unit 30 may be controlled until it is detected that the remaining amount of temperature-controlled substance 200 has become zero or that the above capacity has been recovered.

[0033] Then, after S180 is performed, if no termination command has been received from the ECU (S190: NO), the process returns to S110. If a termination command has been received (S190: YES), this temperature control process ends.

[0034] In the temperature control process described above, S130 and S160 are the temperature control means in this disclosure, S120 and S150 are the supply control means in this disclosure, and S180 is the recovery control means in this disclosure.

[0035] (3) Effects In the secondary battery system 1 of the above embodiment, the pump unit 30 is controlled to circulate the temperature-controlling substance 200 stored in the storage unit 10 through the flow passage 20 into the cell case 120 of the secondary battery 100, thereby directly controlling the temperature inside the secondary battery 100, and thus achieving rapid and uniform temperature control inside.

[0036] Furthermore, in the secondary battery system 1 of the above embodiment, when the secondary battery 100 is outside the target temperature range T0, the temperature control substance 200 within the target temperature range T0 can be circulated into the cell case 120 of the secondary battery 100. Subsequently, after the secondary battery 100 enters the target temperature range, the temperature control substance 200 can be recovered from inside the cell case 120 to the storage unit 10.

[0037] Furthermore, in the secondary battery system 1 of the above embodiment, the encapsulant 130 of the secondary battery 100 has a retracted portion 133 that extends from the encapsulation region 131 to the outside of the cell case 120, and a portion of the electrolyte 113 in the encapsulation region 131 is moved in and out between this retracted portion 133 and the temperature control substance 200 that flows in the circulation region 121.

[0038] In this way, by pushing a portion of the electrolyte 113 into the retraction section 133 and allowing more of the temperature-regulating substance 200 to circulate inside the cell case 120 (circulation area 121), the temperature inside the secondary battery 100 can be effectively regulated.

[0039] Furthermore, in the secondary battery system 1 of the above embodiment, the storage section 10 stores a temperature-regulating substance 200 equivalent to the sum of a second capacity, which is the maximum capacity that can be accommodated in the retraction section 133, and a third capacity, which is the maximum capacity of the temperature-regulating substance 200 circulating in the flow passage 20. As a result, in the secondary battery system 1, simply supplying all the temperature-regulating substance 200 from the storage section 10 to the secondary battery 100 side pushes the electrolyte 113 of the second capacity out of the sealant 130 to the retraction section 133, thereby allowing the electrolyte 113 of the second capacity to reach the retraction section 133 of the sealant 130.

[0040] Furthermore, in the secondary battery system 1 of the above embodiment, the temperature control material 200 is temperature-controlled so that the set temperature is shifted by a predetermined temperature Δt from one of the upper limit T0H and lower limit T0L in the target temperature range T0 to the other. This temperature difference allows for efficient temperature control of the secondary battery 100. Here, by appropriately adjusting the set temperature, more precise temperature control of the secondary battery 100 can be achieved.

[0041] Furthermore, in the secondary battery system 1 of the above embodiment, since the temperature control unit 50 is provided in the flow passage 20, the temperature can be effectively controlled in the area through which the temperature control substance 200 flows, and heat loss and other factors can be suppressed compared to when it is provided in other areas. [Explanation of Symbols]

[0042] 1...Secondary battery system, 10...Storage section, 20...Flow passage, 30...Pump section, 40...Measurement section, 50...Temperature control section, 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, 200...Temperature control substance.

Claims

1. A secondary battery comprising: a cell case for housing electrodes and an electrolyte; a sheet-like sealing body that surrounds and seals the electrodes and electrolyte within the cell case; and a flow hole that reaches from the outside of the cell case to a flow region formed between the inner surface of the cell case and the sealing body. A storage section for storing temperature-regulating substances, A flow passage is connected at one end to the flow hole of the cell case and at the other end to the storage section, The system includes a pump unit that circulates the temperature-controlling substance stored in the storage unit into the flow passage. Secondary battery system.

2. A measuring unit for measuring the temperature of the secondary battery, A temperature control unit that controls the temperature of temperature-controlled substances, A temperature control means controls the temperature control unit so that the temperature-controlled substance flowing in the flow passage stays within a predetermined target temperature range. The system further includes a supply control means for controlling the pump unit so that, when the temperature measured in the measuring unit is outside the target temperature range, the temperature-controlling substance stored in the storage unit is supplied to the cell case via the flow passage. The secondary battery system according to claim 1.

3. The system further includes a recovery control means that controls the pump unit so that, after control by the supply control means is initiated and the temperature measured by the measuring unit falls within the target temperature range, the temperature-controlled substance circulating in the cell case is recovered to the storage unit side via the flow passage. The secondary battery system according to claim 2.

4. 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 system according to claim 3.

5. 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, until the electrolyte pushed out from the sealing region reaches 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 storage section stores a temperature-controlling substance that is equal to or greater than the sum of the second capacity and the third capacity, which is the maximum capacity of the temperature-controlling substance flowing through the flow passage. The supply control means controls the pump section so that the temperature-controlled substance stored in the storage section is supplied to the cell case side in an amount equal to the sum of the second and third capacities. The secondary battery system according to claim 4.

6. The storage section stores a temperature-controlling substance equivalent to the sum of the second and third capacities. The supply control means controls the pump section so that all temperature-controlled substances are supplied from the storage section to the cell case side. The recovery control means controls the pump unit so that all temperature-controlled substances circulating within the cell case are recovered to the storage unit after the temperature measured by the measuring unit falls within the target temperature range. The secondary battery system according to claim 5.

7. The temperature control means controls the temperature control unit so that the temperature-controlled substance flowing in the flow passage is at a temperature that is shifted by a predetermined amount of temperature from one of the upper and lower limits of the target temperature range to the other. A secondary battery system according to any one of claims 2 to 6.

8. The temperature control unit is provided in the flow passage and controls the temperature of the temperature-controlled substance flowing within the flow passage. A secondary battery system according to any one of claims 2 to 6.

9. The temperature control unit is provided in the storage unit and controls the temperature of the temperature control substance stored in the storage unit. A secondary battery system according to any one of claims 2 to 6.

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