All-solid-state battery control system

Abstract

To provide an all-solid-state battery control system for controlling an all-solid-state battery so as to exhibit good performance over a long period of time.SOLUTION: An all-solid-state battery control system includes (1) an all-solid battery containing a solid electrolyte, (2) an enclosure with a space for housing the all-solid-state battery, (3) a fluid that fills the space of the housing, (4) a pressurizing device that applies pressure to the all-solid-state battery via the fluid, and (5) a control unit that controls the magnitude of the pressure applied by the pressuring device to the all-solid-state battery on the basis of the temperature of the all-solid-state battery and the SOC of the all-solid-state battery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an all-solid-state battery control system that controls an all-solid-state battery having a battery element including a solid electrolyte. [Background technology]

[0002] An all-solid-state battery has been proposed in which a battery element containing a solid electrolyte is pressurized with oil to stabilize the power output (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-34002 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an all-solid-state battery, it is desirable to suppress the deterioration of battery performance due to charging and discharging, for example, and to be able to use it for a longer period of time. Therefore, an all-solid-state battery control system is provided that controls an all-solid-state battery so that it exhibits good performance for a longer period of time. [Means for solving the problem]

[0005] An all-solid-state battery control system according to one embodiment of the present disclosure includes the following (1) to (5). (1) All-solid-state batteries containing solid electrolytes (2) A housing with space to accommodate an all-solid-state battery (3) A fluid that fills the space in the housing. (4) A pressure device that applies pressure to the all-solid-state battery via fluid. (5) A control unit that controls the amount of pressure applied to the all-solid-state battery by the pressure device based on the temperature of the all-solid-state battery and the SOC (State Of Charge) of the all-solid-state battery.

[0006] In the all-solid-state battery control system according to an embodiment of the present disclosure, the pressure applied to the all-solid-state battery by the pressure device is controlled by the control unit based on the temperature of the all-solid-state battery and the SOC of the all-solid-state battery, thereby stably maintaining the ionic conductivity in the solid electrolyte. Effect of the Invention

[0007] According to an all-solid-state battery control system according to an embodiment of the present disclosure, it is possible to control an all-solid-state battery so that the all-solid-state battery exhibits good performance for a longer period of time. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a schematic configuration of an all-solid-state battery control system according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing the configuration of the all-solid-state battery shown in FIG. [Diagram 3] FIG. 2 is a schematic diagram illustrating an example of a schematic configuration of a vehicle equipped with the all-solid-state battery control system shown in FIG. [Figure 4] 2 is a flow chart showing control of an all-solid-state battery in the all-solid-state battery control system shown in FIG. 1. [Diagram 5] FIG. 2 is an explanatory diagram illustrating an example of a look-up table showing the relationship between the temperature of the all-solid-state battery shown in FIG. 1 and the SOC of the all-solid-state battery. [Figure 6] 2 is a flow chart showing details of some steps of the flow chart shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 1. Embodiment 1.1 Configuration of the solid-state battery control system that controls the solid-state battery 1.2 Structure of all-solid-state batteries 1.3 Configuration of the control section 1.4 Configuration of vehicle equipped with solid-state battery control system 1.5 Vehicle Operation 1.6 Control of solid-state batteries 1.7 Effects 2. Variations

[0010] <1. Preferred embodiment> [1.1 Schematic configuration of the all-solid-state battery control system 100] 1 is a diagram illustrating a schematic configuration example of an all-solid-state battery control system 100 according to an embodiment of the present disclosure. As illustrated in FIG. 1, the all-solid-state battery control system 100 includes an all-solid-state battery 1, a housing 2, a pressurizing device 3, a tank 4, a fluid temperature adjustment device 5, fluid flow paths 6A and 6B, and a control unit 7.

[0011] The all-solid-state battery 1 is a secondary battery that contains a solid electrolyte as an electrolyte. The detailed configuration of the all-solid-state battery 1 will be described later.

[0012] The housing 2 is a container having a space V2. The space V2 accommodates the all-solid-state battery 1. The housing 2 may be made of a rigid body such as stainless steel. The space V2 of the housing 2 is filled with a fluid F. The fluid F is, for example, insulating oil. The fluid F may be anything other than oil as long as it can transmit pressure. A terminal section 20 having two output terminals 21 and 22 is provided on the outer surface of the housing 2. The output terminals 21 and 22 are conductive parts that extract the output voltage of the all-solid-state battery 1. For example, the output terminal 21 is connected to the negative electrode 11 (described later) of the all-solid-state battery 1, and the output terminal 21 is connected to the positive electrode 12 (described later) of the all-solid-state battery 1.

[0013] The pressurizing device 3 is a device that applies pressure to the all-solid-state battery 1 via the fluid F, and is, for example, a pressure pump. The pressurizing device 3 is connected to, for example, a control unit 7 so as to be able to communicate with the control unit 7. The pressurizing device 3 is capable of increasing or decreasing the pressure on the all-solid-state battery 1 via the fluid F based on a command from the control unit 7.

[0014] The tank 4 is a container for storing a fluid F.

[0015] The fluid temperature adjustment device 5 has a heater 51 that heats the fluid F and a chiller 52 that cools the fluid F. The fluid temperature adjustment device 5 is communicably connected to, for example, the control unit 7. The fluid temperature adjustment device 5 is capable of adjusting the temperature of the fluid F by heating the fluid F with the heater 51 or cooling the fluid F with the chiller 52 based on a command from the control unit 7.

[0016] The space V2 of the housing 2 and the tank 4 are connected by the fluid flow paths 6A and 6B. Both of the fluid flow paths 6A and 6B are tubular members made of a rigid body such as stainless steel. The pressurizing device 3 is disposed in the fluid flow path 6A connecting the housing 2 and the tank 4. Therefore, the fluid F is confined in a closed space formed by the space V2 of the housing 2, the tank 4, and the fluid flow paths 6A and 6B, and the pressurizing device 3 circulates the fluid F inside the closed space. Specifically, the fluid F that has arrived at the pressurizing device 3 is sequentially pumped by the pressurizing device 3, so that the fluid F reaches the space V2 through the fluid flow path 6A, and then reaches the tank 4 through the fluid flow path 6B. Then, the fluid returns to the pressurizing device 3 through the fluid flow path 6A. A heater 51 is disposed in the portion of the fluid flow path 6A between the housing 2 and the pressurizing device 3. A chiller 52 is disposed in the fluid flow path 6B connecting the housing 2 and the tank 4. A fan (or pump) 6C for circulating the fluid F may be further disposed in the fluid flow path 6B between the housing 2 and the chiller 52.

[0017] The all-solid-state battery control system 100 may further include a pressure gauge PG and two thermometers HG1 and HG2. The pressure gauge PG is attached, for example, to a portion of the fluid flow path 6A that connects the heater 51 and the housing 2. The pressure gauge PG measures the pressure of the fluid F. The thermometer HG1 measures the temperature of the all-solid-state battery 1, for example, the temperature of the battery element 10. The thermometer HG2 measures, for example, the temperature of the fluid F present inside the space V2.

[0018] The control unit 7 controls the operation of the pressurizing device 3 to adjust the magnitude of pressure that the pressurizing device 3 applies to the all-solid-state battery 1 via the fluid F. Furthermore, the control unit 7 controls the operations of the heater 51 and the chiller 52 of the fluid temperature adjustment device 5 to adjust the temperature of the fluid F. The control unit 7 will be described in detail later.

[0019] [1.2 Structure of all-solid-state battery 1] Next, the configuration of the all-solid-state battery 1 will be described in detail with reference to Fig. 2 in addition to Fig. 1. Fig. 2 is a cross-sectional view showing the internal configuration of a battery element 10 of the all-solid-state battery 1.

[0020] 1, the all-solid-state battery 1 has a plurality of battery elements 10. The plurality of battery elements 10 are, for example, connected in series with each other and folded on top of each other in a zigzag shape.

[0021] 2, each battery element 10 has a laminated structure 10S including an anode 11, a cathode 12, and a solid electrolyte layer 13 sandwiched therebetween. The anode 11 is, for example, an anode active material layer 11B laminated on an anode current collector 11A. The cathode 12 is, for example, an anode active material layer 12B laminated on a cathode current collector 12A. The anode active material layer 11B and the cathode active material layer 12B are each configured to face the solid electrolyte layer 13.

[0022] The solid electrolyte layer 13 includes, for example, a solid electrolyte. The solid electrolyte has lithium ion conductivity, and is preferably a sulfide-based inorganic solid electrolyte. This is because a sulfide-based inorganic solid electrolyte can provide higher ion conductivity than other inorganic compounds. Specifically, for example, an inorganic solid electrolyte obtained by combining Li2S with SiS2, GeS2, P2S5, or B2S3 can be used.

[0023] The negative electrode current collector 11A is, for example, a metal foil, specifically, for example, a copper foil, and the positive electrode current collector 12A is, for example, a metal foil, specifically, for example, an aluminum foil.

[0024] The negative electrode active material layer 11B is, for example, a negative electrode composite layer formed by mixing a particulate negative electrode active material with a solid electrolyte. The negative electrode active material layer 11B may further include a binder or a conductive assistant. As the negative electrode active material, for example, a carbon material or a metal such as Sn (tin) or In (indium) can be suitably used. Specifically, in addition to natural graphite and various graphites, metal powders such as Sn, Si (silicon), Al, Sb (antimony), Zn (zinc), and Bi (bismuth), metal alloy powders such as Sn5Cu6, Sn2Co, and Sn2Fe, and other amorphous alloys and plated alloys can be mentioned.

[0025] The positive electrode active material layer 12B is a positive electrode composite layer formed by mixing, for example, a particulate positive electrode active material with a solid electrolyte. The positive electrode active material layer 12B may further include a binder and a conductive assistant. As the positive electrode active material, for example, a composite oxide of lithium and a transition metal can be suitably used. Specific examples include LiCoO2, LiNiCoO2, LiNiO2, LiNiCoAlO2, LiNiMnCoO2, LiFeMnO2, Li2PtO3, LiMnNiO4, LiMn2O4, LiNiMnO2, LiNiVO4, LiCrMnO4, LiFePO4, LiFe(SO4)3, LiCoVO4, LiCoPO4, and S.

[0026] The battery element 10 further includes a negative electrode lead 14, a positive electrode lead 15, and a packaging material 16. The laminated structure 10S is sealed by the packaging material 16.

[0027] The negative electrode lead 14 has a first end 14A connected to the negative electrode current collector 11A and a second end 14B extending to the outside of the packaging material 16 on the opposite side to the first end 14A. The negative electrode lead 14 is electrically insulated by an insulator 17 from a portion of the laminate structure 10S other than the negative electrode current collector 11A. The positive electrode lead 15 has a first end 15A connected to the positive electrode current collector 12A and a second end 15B extending to the outside of the packaging material 16 on the opposite side to the first end 15A. The positive electrode lead 15 is electrically insulated by an insulator 18 from a portion of the laminate structure 10S other than the positive electrode current collector 12A.

[0028] The negative electrode lead 14 and the positive electrode lead 15 are connected to each other so that the stacked structure 10S of the multiple battery elements 10 is connected in series. As shown in FIG. 1, for example, the negative electrode lead 14 of the uppermost battery element 10 is connected to an output terminal 21, and the positive electrode lead 15 of the lowermost battery element 10 is connected to an output terminal 22.

[0029] The packaging material 16 hermetically packages the laminated structure 10S. The packaging material 16 is made of a material having excellent flexibility and stretchability, such as rubber.

[0030] [1.3 Configuration of the control unit 7] As already described, the control unit 7 is communicably connected to the pressurizing device 3, and controls the pressure on the all-solid-state battery 1 by the pressurizing device 3. The control unit 7 is configured using a circuit including a microcomputer equipped with a CPU (Central Processing Unit) 7A, a ROM (Read Only Memory) 7B, and a RAM (Random Access Memory) 7C, for example, as shown in FIG. 1. The processing by the control method in the technology of the present disclosure can be realized by the CPU executing a program stored in the ROM or RAM. Note that the processing by the control method in the technology of the present disclosure may be realized by the CPU executing a process based on a program supplied from the outside by, for example, wired or wireless communication. The control unit 7 is communicably connected to, for example, a pressure gauge PG. Therefore, the control unit 7 is capable of obtaining pressure information of the fluid F from the pressure gauge PG. In addition, the control unit 7 is communicably connected to, for example, a thermometer HG1. Therefore, the control unit 7 is capable of obtaining temperature information of the battery element 10 of the all-solid-state battery 1 from the thermometer HG1. In addition, the control unit 7 is communicably connected to, for example, a thermometer HG2. Therefore, the control unit 7 can obtain temperature information of the fluid F inside the space V2 from the thermometer HG2. Furthermore, the control unit 7 is communicably connected to the terminal unit 20. Therefore, the control unit 7 can obtain information on the SOC (State Of Charge) of the all-solid-state battery 1 and information on the internal resistance value of the all-solid-state battery 1 from the terminal unit 20. The pressure control for the all-solid-state battery 1 is performed based on, for example, the temperature of the all-solid-state battery 1 and the SOC of the all-solid-state battery 1. The control unit 7 may be communicably connected to an external device 101 provided outside the all-solid-state battery control system 100.

[0031] The control unit 7 may control the pressure device 3 to increase the pressure on the all-solid-state battery 1 continuously or stepwise as the temperature of the battery element 10 of the all-solid-state battery 1 decreases. In the all-solid-state battery 1, the lower the temperature, the more the laminated structure 10S of the battery element 10 shrinks. Therefore, gaps are likely to occur at the interface between the negative electrode collector 11A and the negative electrode active material layer 11B, the interface between the negative electrode active material layer 11B and the solid electrolyte layer 13, the interface between the solid electrolyte layer 13 and the positive electrode active material layer 12B, and the interface between the positive electrode active material layer 12B and the positive electrode collector 12A. Therefore, by increasing the pressure on the all-solid-state battery 1 as the temperature decreases, the movement path of the charge element such as lithium ions is sufficiently secured, and the increase in the internal resistance value can be suppressed.

[0032] The control unit 7 may control the pressure device 3 to increase the pressure on the battery element 10 continuously or stepwise as the SOC of the all-solid-state battery 1 decreases, for example. In the all-solid-state battery 1, the lower the SOC, the more the laminated structure 10S of the battery element 10 shrinks. Therefore, gaps are likely to occur at the interface between the negative electrode collector 11A and the negative electrode active material layer 11B, the interface between the negative electrode active material layer 11B and the solid electrolyte layer 13, the interface between the solid electrolyte layer 13 and the positive electrode active material layer 12B, and the interface between the positive electrode active material layer 12B and the positive electrode collector 12A. Therefore, by increasing the pressure on the all-solid-state battery 1 as the SOC decreases, the movement path of the charge element such as lithium ions is sufficiently secured, and the increase in the internal resistance value can be suppressed.

[0033] Furthermore, the control unit 7 may control the pressurizing device 3 to perform preliminary pressurization to preliminarily increase the pressure on the battery element 10 when high-load discharge of the all-solid-state battery 1 is predicted based on information from the outside (for example, the external device 101). The information from the outside here corresponds to, for example, when the all-solid-state battery control system 100 is mounted on a vehicle 200 described later, information on a change in the vehicle operation mode, map information, or driving history information of the vehicle 200 transmitted from an ECU 213 described later. Furthermore, the control unit 7 may use AI (artificial intelligence) to learn the past driving history of the vehicle 200 and predict the timing of high-load discharge of the all-solid-state battery 1.

[0034] Furthermore, the control unit 7 may control the pressurizing device 3 to perform preliminary pressurization to preliminarily increase the pressure on the battery element 10 when it is predicted based on information from the outside (for example, the external device 101) that the all-solid-state battery 1 will switch from a charging state to a discharging state. The information from the outside here corresponds to, for example, when the all-solid-state battery control system 100 is mounted on a vehicle 200 described later, information on the duration of the charging state when the vehicle 200 is running, map information, or driving history information of the vehicle 200, transmitted from the ECU 213. Furthermore, the control unit 7 may use AI (artificial intelligence) to learn the past driving history of the vehicle 200 and predict the timing of switching from the charging state to the discharging state of the all-solid-state battery 1.

[0035] Furthermore, the control unit 7 may control the pressurizing device 3 to apply additional pressure to the all-solid-state battery 1 according to the degree of deterioration of the solid electrolyte included in the battery element 10. In this case, the control unit 7 can determine the degree of deterioration of the solid electrolyte based on the accumulated usage time of the all-solid-state battery 1 or deterioration degree estimation data.

[0036] Furthermore, the control unit 7 may control the magnitude of the pressure applied to the all-solid-state battery 1 based on the internal resistance value of the all-solid-state battery 1. The control unit 7 is configured to be able to obtain information on the internal resistance value of the all-solid-state battery 1 from the terminal unit 20, for example.

[0037] [1.4 Configuration of vehicle 200] Next, a description will be given of the configuration of a vehicle 200 equipped with the above-described all-solid-state battery control system 100. Fig. 3 is a diagram illustrating a schematic configuration example of a vehicle 200 equipped with an all-solid-state battery control system 100 according to an embodiment of the present disclosure.

[0038] As shown in FIG. 3, the vehicle 200 is an EV (electric vehicle). The vehicle 200 includes a vehicle body 201, a front wheel motor 211, a rear wheel motor 221, a pair of front wheels 202, and a pair of rear wheels 203. The vehicle 200 runs by rotating at least one of the pair of front wheels 202 and the pair of rear wheels 203 by a driving force transmitted from at least one of the front wheel motor 211 and the rear wheel motor 221. The vehicle 200 further includes a front wheel power transmission mechanism 212, a rear wheel power transmission mechanism 222, an ECU (Electronic Control Unit) 213, a front wheel drive circuit 214, and a rear wheel drive circuit 224. The pair of front wheels 202 are attached to both ends of an axle 202S held by the front wheel power transmission mechanism 212, and the pair of rear wheels 203 are attached to both ends of an axle 203S held by the rear wheel power transmission mechanism 222.

[0039] The front wheel motor 211 is, for example, a three-phase AC motor, and is configured to be able to generate a drive torque that rotates the front wheels 202 by AC power supplied from the front wheel drive circuit 214. The front wheel motor 211 generates a drive torque that rotates the front wheels 202 forward when moving the vehicle 200 forward, and generates a drive torque that rotates the front wheels 202 backward when moving the vehicle 200 backward.

[0040] The front wheel power transmission mechanism 212 is configured to be able to transmit the driving torque transmitted from the front wheel motor 211 to the front wheels 202 via the axle 202S. The front wheel power transmission mechanism 212 is a gear mechanism including, for example, a torque converter, a transmission, a differential gear, and the like.

[0041] The rear wheel motor 221 is, for example, a three-phase AC motor, and is configured to be able to generate a drive torque that rotates the rear wheels 203 by AC power supplied from the rear wheel drive circuit 224. The rear wheel motor 221 generates a drive torque that rotates the rear wheels 203 forward when moving the vehicle 200 forward, and generates a drive torque that rotates the rear wheels 203 backward when moving the vehicle 200 backward.

[0042] The rear wheel power transmission mechanism 222 is configured to be able to transmit the driving torque transmitted from the rear wheel motor 221 to the rear wheels 203 via the axle 203S. The rear wheel power transmission mechanism 222 is a gear mechanism including, for example, a torque converter, a transmission, a differential gear, and the like.

[0043] The front wheel drive circuit 214 and the rear wheel drive circuit 224 are configured to convert the DC power supplied from the all-solid-state battery control system 100 into AC power based on a control signal from the ECU 213, and output the AC power to the front wheel motor 211 and the rear wheel motor 221, respectively.

[0044] The ECU 213 controls the driving operation of the vehicle 200. At that time, the ECU 213 comprehensively judges the driving state of the vehicle 200 based on various information such as detection signals from the operation unit 205 and the sensor group 207. The sensor group 207 has, for example, a plurality of sensors that detect the environment in which the vehicle 200 is placed and the driving state of the vehicle 200. Specifically, the sensor group 207 has, for example, an accelerator opening sensor that detects an accelerator opening, a speed sensor that detects the driving speed of the vehicle 200, or a gradient sensor that detects the gradient of the road surface on which the vehicle 200 runs. The sensor group 207 transmits detection signals including various information from the various sensors described above to the ECU 213. The ECU 213 is configured using a circuit including a microcomputer equipped with, for example, a CPU (Central Processing Unit) 213A, a ROM (Read Only Memory) 213B, and a RAM (Random Access Memory) 213C. The ECU 213 is communicably connected to, for example, the control unit 7 (FIG. 1) of the all-solid-state battery control system 100. The ECU 213 transmits various information related to the traveling of the vehicle 200 to the control unit 7 (FIG. 1). For example, information related to a change in the vehicle driving mode input by the driver from the operation unit 205, map information, or traveling history information of the vehicle 200 is transmitted from the ECU 213 to the control unit 7.

[0045] [1.5 Vehicle 200 Operation] (Vehicle moving forward) When moving the vehicle 200 forward, the driver operates the operation unit 205 to select a drive range. When the drive range is selected by the operation unit 205, the ECU 213 outputs appropriate torque signals to the front wheel drive circuit 214 and the rear wheel drive circuit 224, respectively, to start the front wheel motor 211 and the rear wheel motor 221. The front wheel motor 211 and the rear wheel motor 221 generate drive torques for rotating the front wheels 202 and the rear wheels 203 in the forward direction, respectively. As a result, the drive torques are transmitted to the front wheels 202 and the rear wheels 203 via the front wheel power transmission mechanism 212 and the rear wheel power transmission mechanism 222, and the axles 202S and 203S, respectively, and the front wheels 202 and the rear wheels 203 rotate in the forward direction, respectively. As a result, the vehicle 200 moves forward.

[0046] (Vehicle reversing) When moving the vehicle 200 backward, the driver operates the operation unit 205 to select the reverse range. When the reverse range is selected in the operation unit 205, the front wheel drive circuit 214 and the rear wheel drive circuit 224 start the front wheel motor 211 and the rear wheel motor 221 based on a torque signal from the ECU 213. Here, the front wheel motor 211 and the rear wheel motor 221 generate drive torque that rotates the front wheels 202 and the rear wheels 203 in the direction opposite to that when the vehicle is moving forward. This causes the front wheels 202 and the rear wheels 203 to rotate in the opposite direction to that when the vehicle is moving forward, and the vehicle 200 is moved backward.

[0047] [1.6 Control of solid-state battery 1] Next, control of the all-solid-state battery 1 in the all-solid-state battery control system 100 shown in Fig. 1 will be described with reference to Fig. 4. Fig. 4 is a flow diagram showing control of the all-solid-state battery 1 in the all-solid-state battery control system 100 mounted on the vehicle 200 in Fig. 3.

[0048] First, the control unit 7 determines whether the vehicle 200 is running based on information from the ECU 213 as the external device 101 (step S101). If it is determined in step S101 that the vehicle 200 is not running (step S101N), step S101 is repeated until it is determined that the vehicle 200 is running.

[0049] In step S101, when it is determined that the vehicle 200 is traveling (step S101Y), the control unit 7 controls the magnitude of pressure applied by the pressurizing device 3 to the all-solid-state battery 1 (step S102). At that time, the control unit 7 controls the pressure on the all-solid-state battery 1 based on temperature information of the all-solid-state battery 1 from the thermometer HG1 and SOC information of the all-solid-state battery 1. Specifically, the control unit 7 may control the operation of the pressurizing device 3 so that an appropriate pressure is applied to the battery element 10 according to, for example, a lookup table (e.g., FIG. 5) created in advance.

[0050] FIG. 5 is an example of a lookup table showing the relationship between the temperature (battery temperature) [°C] of the all-solid-state battery 1 and the SOC [%] of the all-solid-state battery 1. In FIG. 5, five battery temperature levels, −30, 0, 20, 40, and 60°C, are shown, and appropriate pressure levels for the all-solid-state battery 1 corresponding to four SOC levels in the range of 20 to 80% are shown by symbols A to H for each level. In Table 5, among the pressure levels A to H, the pressure level A is the lowest value, followed by the pressure levels B, C, D, E, F, and G in that order, with the pressure level H being the highest value. As shown in Table 5, the control unit 7 may control the pressurizing device 3 so as to increase the pressure on the all-solid-state battery 1 continuously or stepwise as the temperature of the all-solid-state battery 1 decreases. In addition, the control unit 7 may control the pressurizing device 3 so as to increase the pressure on the all-solid-state battery 1 continuously or stepwise as the SOC of the all-solid-state battery 1 decreases. Furthermore, the control unit 7 may roughly adjust the pressure applied to the all-solid-state battery 1 based on the temperature of the all-solid-state battery 1 and the SOC of the all-solid-state battery 1 as described above, and may also finely adjust the pressure applied to the all-solid-state battery based on, for example, the internal resistance value of the all-solid-state battery 1.

[0051] Furthermore, the control unit 7 may control the temperature of the all-solid-state battery 1 when controlling the pressure on the all-solid-state battery 1. Specifically, the temperature of the fluid F is adjusted by controlling the operation of the fluid temperature regulator 5 so that the temperature of the battery element 10 is appropriate for discharging the battery element 10. The temperature of the battery element 10 appropriate for discharging the battery element 10 is, for example, −30° C. or higher and +60° C. or lower. In this way, by appropriately maintaining the temperature of the battery element 10 of the all-solid-state battery 1, the battery performance of the all-solid-state battery 1 can be fully exhibited.

[0052] After step S102, the control unit 7 judges whether the internal resistance value of the laminated structure 10S of the battery element 10 is likely to increase (step S103). The situation where the internal resistance value is likely to increase here is a concept that includes a case where the internal resistance value is already in a state where it is likely to increase at that time, as well as a case where the internal resistance value is expected to become in a state where it is likely to increase thereafter. If it is judged in step S103 that the internal resistance value of the laminated structure 10S of the battery element 10 is not in a state where it is likely to increase (step S103N), the control unit 7 performs the process of step S105 without going through step S104 described later.

[0053] In step S103, if it is determined that the internal resistance value of the laminated structure 10S of the battery element 10 is likely to increase (step S103Y), the control unit 7 preliminarily further increases the pressure on the all-solid-state battery 1 (step S104). After that, the control unit 7 performs the process of step S105. In step S105, the control unit 7 determines again whether the vehicle 200 is running based on information from the ECU 213 as the external device 101 (step S105). If it is determined that the vehicle 200 is running in step S105 (step S105Y), the process returns to step S102. If it is determined that the vehicle 200 is not running (step S105N), the control of the all-solid-state battery 1 ends as it is (END).

[0054] There are three cases, for example, where the internal resistance value of the laminate structure 10S in step S103 is likely to increase. FIG. 6 is a flow chart showing the control of the all-solid-state battery 1 that further embodies the process of step S103. The first of the above three cases is a case where high-load discharge of the all-solid-state battery 1 is predicted. The second case is a case where the all-solid-state battery 1 is predicted to switch from a charging state to a discharging state. The third case is a case where degradation of the solid electrolyte included in the laminate structure 10S progresses.

[0055] As shown in FIG. 6, the control unit 7 judges whether or not high-load discharge of the all-solid-state battery 1 is predicted based on, for example, information from the ECU 213 (step S201). For example, when the driver switches to a vehicle driving mode that requires higher output, or when the vehicle 200 is expected to reach a steep uphill slope within a predetermined time, the high-load discharge of the all-solid-state battery 1 is predicted. When the all-solid-state battery 1 performs such high-load discharge, the laminated structure 10S rapidly contracts. This may cause insufficient contact between the negative electrode 11 and the positive electrode 12 and the solid electrolyte layer 13, resulting in an increase in the internal resistance value. Therefore, when it is judged that high-load discharge of the all-solid-state battery 1 is predicted (step S201Y), in step S104 (FIG. 4), the control unit 7 controls the pressurizing device 3 to perform preliminary pressurization to preliminarily increase the pressure on the all-solid-state battery 1.

[0056] When it is not determined that the high-load discharge of the all-solid-state battery 1 is predicted (step S201N), the process proceeds to step S202. In step S202, the control unit 7 determines whether or not it is predicted that the all-solid-state battery 1 will switch from a charging state to a discharging state, for example, based on information from the ECU 213. For example, when the vehicle 200 continues to run downhill for a predetermined time, the input of regenerative power to the all-solid-state battery 1 continues for a predetermined time, and then the vehicle runs on a flat road or uphill, this corresponds to a case in which it is predicted that the charging state will switch to the discharging state. When switching from charging to discharging, it is expected that the laminated structure 10S will suddenly contract. Therefore, the contact between the negative electrode 11 and the positive electrode 12 and the solid electrolyte layer 13 becomes insufficient, which may cause an increase in the internal resistance value and irreversible capacity deterioration. Therefore, when it is determined that the charging state is predicted to switch to the discharging state (step S202Y), in step S104 (FIG. 4), the control unit 7 controls the pressurizing device 3 to perform preliminary pressurization to preliminarily increase the pressure on the all-solid-state battery 1.

[0057] When it is not determined that the charge state is predicted to be switched to the discharge state (step S202N), the process proceeds to step S203. In step S203, the control unit 7 determines whether the solid electrolyte included in the laminated structure 10S is deteriorating. The degree of degradation of the solid electrolyte is determined based on the accumulated usage time of the all-solid-state battery 1 and the degradation degree estimation data. When the degradation of the solid electrolyte is deteriorating, there is a possibility that the internal resistance value of the all-solid-state battery 1 increases. Therefore, when it is determined that the degradation of the solid electrolyte is deteriorating (step S203Y), in step S104 (FIG. 4), the control unit 7 controls the pressurizing device 3 to perform preliminary pressurization to preliminarily increase the pressure on the all-solid-state battery 1. When it is not determined that the degradation of the solid electrolyte is deteriorating (step S203N), the process proceeds to step S105 (FIG. 4) without passing through step S104. The process of the control unit 7 in step S105 is as described above.

[0058] [Actions and Effects of the All-Solid-State Battery Control System 100] In this way, according to the all-solid-state battery control system 100 of the present embodiment and the vehicle 200 equipped with the same, the pressure applied by the pressurizing device 3 to the all-solid-state battery 1 is controlled by the control unit 7 based on the temperature of the all-solid-state battery 1 and the SOC of the all-solid-state battery 1. Therefore, it is possible to reduce the fluctuation in the output performance of the all-solid-state battery 1 that may occur due to the temperature of the all-solid-state battery 1 and the state of the SOC of the all-solid-state battery 1. That is, the ion conductivity of the solid electrolyte is stably maintained. Therefore, according to the all-solid-state battery control system 100, it is possible to control the all-solid-state battery 1 so that the all-solid-state battery 1 exhibits good performance for a longer period of time.

[0059] Specifically, for example, when the temperature of the all-solid-state battery 1 is low, the laminated structure 10S of the battery element 10 shrinks, and gaps are likely to occur at the interfaces between the negative electrode 11 and the positive electrode 12 and the solid electrolyte layer 13. In such a case, by applying pressure to the laminated structure 10S from the outside of the packaging material 16 using the fluid F, the gaps at the interfaces between the negative electrode 11 and the positive electrode 12 and the solid electrolyte layer 13 can be reduced, and the migration path of the charge element such as lithium ions can be sufficiently secured. As a result, the increase in the internal resistance value can be suppressed, and good output performance can be obtained. In other words, the all-solid-state battery 1 can be controlled so that the deterioration of the battery performance is suppressed and good performance can be exhibited over a long period of time.

[0060] In addition, when the SOC of the all-solid-state battery 1 is low, the laminated structure 10S of the battery element 10 shrinks, and gaps tend to form inside the laminated structure 10S. In this case, as in the case where the temperature of the all-solid-state battery 1 is low, pressure is applied to the laminated structure 10S from the outside of the packaging material 16 by the fluid F, thereby reducing the gaps at the interfaces between the negative electrode 11 and the positive electrode 12 and the solid electrolyte layer 13, and the like, and a sufficient migration path for charge elements such as lithium ions can be secured. As a result, an increase in the internal resistance value can be suppressed, and good output performance can be obtained.

[0061] Moreover, in the all-solid-state battery control system 100 of the present embodiment, the control unit 7 monitors the internal resistance value of the all-solid-state battery 1, and based on the internal resistance value, the pressure applied to the all-solid-state battery 1 by the pressurizing device 3 can be controlled. In this way, pressure control can be performed with higher accuracy, and more stable output performance can be obtained.

[0062] Moreover, according to the all-solid-state battery control system 100 of the present embodiment, the heater 51 and the chiller 52 can control the temperature of the fluid F. Therefore, for example, the temperature of the fluid F can be adjusted so that the temperature of the battery element 10 is appropriate for discharging the battery element 10. Therefore, by appropriately maintaining the temperature of the battery element 10 of the all-solid-state battery 1, the battery performance of the all-solid-state battery 1 can be fully exhibited.

[0063] Furthermore, in the all-solid-state battery control system 100 of this embodiment, when high-load discharge of the all-solid-state battery 1 is predicted based on external information, the control unit 7 can perform preliminarily pressurizing to preliminarily increase the pressure on the battery element 10. When preliminarily pressurizing is performed, fluctuations (especially sudden increases) in the internal resistance value can be suppressed compared to when preliminarily pressurizing is not performed, and stable battery performance can be exhibited.

[0064] Furthermore, in the all-solid-state battery control system 100 of this embodiment, when it is predicted based on external information that the all-solid-state battery 1 will switch from a charging state to a discharging state, the control unit 7 can perform preliminarily pressurizing to preliminarily increase the pressure on the battery element 10. When preliminarily pressurizing is performed, fluctuations (especially sudden increases) in the internal resistance value can be suppressed compared to when preliminarily pressurizing is not performed, and stable battery performance can be exhibited.

[0065] Furthermore, in the all-solid-state battery control system 100 of the present embodiment, the control unit 7 can control the pressurizing device 3 to apply additional pressure to the all-solid-state battery 1 according to the degree of deterioration of the solid electrolyte contained in the battery element 10. Compared to a case in which the degree of deterioration of the solid electrolyte is not taken into consideration, a higher battery performance can be achieved.

[0066] <2. Modifications> Although the present disclosure has been described above by way of the embodiments, the present disclosure is not limited to these embodiments and can be modified in various ways.

[0067] For example, in the above embodiment, the all-solid-state battery control system is mounted on a vehicle, but the present disclosure is not limited thereto. The present disclosure may be an all-solid-state battery control system mounted on a vehicle other than a vehicle, such as a ship or an aircraft. Alternatively, the all-solid-state battery control system of the present disclosure may be mounted on a device that does not move, such as a construction machine or a work robot, and may control an all-solid-state battery used as a power source for the device. For example, the all-solid-state battery control system may be an all-solid-state battery control system that controls an all-solid-state battery used as a household power source. Even in this case, stable output performance can be obtained over a long period of time by controlling the pressure applied to the all-solid-state battery in response to changes in environmental temperature and SOC.

[0068] In the above embodiment, the control unit obtains external information from a wired external device, but the present disclosure is not limited to this. For example, the control unit may obtain external information from a wirelessly connected external device.

[0069] It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained. [Explanation of symbols]

[0070] 100... all-solid-state battery control system, 101... external device, 1... all-solid-state battery, 10... battery element, 10S... laminated structure, 11... negative electrode, 11A... negative electrode current collector, 11B... negative electrode active material layer, 12... positive electrode, 12A... positive electrode current collector, 12B... positive electrode active material layer, 13... solid electrolyte layer, 14... negative electrode lead, 15... positive electrode lead, 16... packaging material, 17, 18... insulator, 2... housing, 20... terminal portion, 21, 22... output terminal, 3... pressure device, 4... tank, 5... fluid temperature control device, 51... heater motor, 52... chiller, 6A, 6B... fluid flow path, 6C... fan (or pump), 7... control unit, 200... vehicle, 201... vehicle body, 202... front wheels, 202S... axles, 203... rear wheels, 203S... axles, 207... sensor group, 211... front wheel motor, 212... front wheel power transmission mechanism, 221... rear wheel motor, 222... rear wheel power transmission mechanism, 213... ECU, 214... front wheel drive circuit, 224... rear wheel drive circuit, F... fluid, HG1, HG2... thermometer, PG... pressure gauge, V2... space.

Claims

1. an all-solid-state battery including a solid electrolyte; A housing having a space for accommodating the all-solid-state battery; A fluid that is filled in the space of the housing; and A pressure device that applies pressure to the all-solid-state battery via the fluid; a control unit that controls the magnitude of the pressure applied to the all-solid-state battery by the pressure device based on a temperature of the all-solid-state battery and a state of charge (SOC) of the all-solid-state battery; An all-solid-state battery control system equipped with

2. The fluid may further include a heater. The all-solid-state battery control system according to claim 1 .

3. The system further includes a chiller for cooling the fluid. The all-solid-state battery control system according to claim 1 or 2.

4. The all-solid-state battery has a laminated structure and a flexible packaging material that seals the laminated structure, The laminated structure includes a positive electrode, a negative electrode, and the solid electrolyte sandwiched between the positive electrode and the negative electrode. The all-solid-state battery control system according to any one of claims 1 to 3.

5. The control unit increases the pressure continuously or stepwise as the temperature of the all-solid-state battery decreases. The all-solid-state battery control system according to any one of claims 1 to 4.

6. The control unit increases the pressure continuously or stepwise as the SOC of the all-solid-state battery decreases. The all-solid-state battery control system according to any one of claims 1 to 5.

7. The control unit performs a preliminary pressurization to preliminarily increase the pressure when high-load discharge of the all-solid-state battery is predicted based on information from an external source. The all-solid-state battery control system according to any one of claims 1 to 6.

8. The control unit performs a preliminary pressurization to preliminarily increase the pressure when it is predicted that the all-solid-state battery will switch from a charging state to a discharging state based on information from an external source. The all-solid-state battery control system according to any one of claims 1 to 6.

9. The control unit applies additional pressure to the all-solid-state battery according to a degree of deterioration of the solid electrolyte. The all-solid-state battery control system according to any one of claims 1 to 8.

10. The control unit determines a degree of deterioration of the solid electrolyte based on an integrated usage time of the all-solid-state battery or deterioration degree estimation data. The all-solid-state battery control system according to claim 9.

11. The control unit controls the magnitude of the pressure applied to the all-solid-state battery based on an internal resistance value of the all-solid-state battery. The all-solid-state battery control system according to any one of claims 1 to 10.

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