Pressure regulation system for solid-state battery, pressure management method for solid-state battery, and vehicle

Abstract

The present application discloses a pressure regulation system (100) for a solid-state battery (15), a pressure management method for the solid-state battery (15), and a vehicle. The pressure management method comprises the following steps: acquiring working condition information of the solid-state battery (15); determining an operating state of the solid-state battery (15) on the basis of the working condition information, wherein the operating state includes a sleep state, an active state, and an abnormal heat-generation state; and regulating the pressure of the solid-state battery (15) on the basis of the operating state.

Description

Pressure regulation system and pressure management method of solid-state battery, and vehicle

[0001] The present application claims priority to the Chinese patent application No. 202411071602.6, filed on August 5, 2024, entitled “Pressure regulation system and pressure management method of solid-state battery, and vehicle”, the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a pressure regulation system and pressure management method of solid-state battery, and vehicle. BACKGROUND

[0003] At present, the interface problem of the battery under the electrolyte system is not prominent. When the material expands and shrinks during the operation of the battery, the electrolyte can adapt to the volume change, and there is no disconnection of the physical electrical connection between the material and the electrolyte caused by the volume change. And the current electrolyte system battery uses a small expansion graphite negative electrode, and full SOC and SOH do not need to be continuously pressurized. But the solid-state battery is composed of inorganic solid materials, and needs to maintain continuous pressure during operation to ensure the contact and conduction of active particles.

[0004] However, because the electronic conductivity in the electrolyte of the solid-state battery is significantly higher than that of the electrolyte, the self-discharge of the solid-state battery is more serious, which will cause the self-discharge of the solid-state battery to be much higher than that of the electrolyte system battery, so that the calendar life of the solid-state battery is greatly shortened. SUMMARY

[0005] In view of the above problems, the present application provides a pressure regulation system and pressure management method of solid-state battery, and vehicle, which can prolong the service life of the solid-state battery and improve its electrical performance by adjusting the pressure of the solid-state battery under different operating conditions.

[0006] The present application provides a pressure management method of solid-state battery, comprising the following steps: obtaining working condition information of the solid-state battery; determining an operating state of the solid-state battery according to the working condition information, the operating state comprising: a dormant state, an activated state and an abnormal heat release state; adjusting the pressure of the solid-state battery according to the operating state.

[0007] According to the pressure management method of the solid-state battery, the management control logic is configured to first acquire working condition information of the solid-state battery, determine the running state of the solid-state battery according to the working condition information, and then adjust the pressure of the solid-state battery according to the running state of the solid-state battery. In this way, when the solid-state battery is in different states, the matching pressure can be provided to ensure that the solid-state battery has the electrical performance adapted to the state, which is beneficial to maximize the energy saving and utilization of the solid-state battery, prolong the service life of the solid-state battery, improve the reliability of the solid-state battery, and help improve the user experience of the vehicle.

[0008] In some embodiments, the adjusting the pressure of the solid-state battery according to the running state comprises: determining that the solid-state battery is in a dormant state; and depressurizing the solid-state battery.

[0009] In some embodiments, the working condition information comprises a working current of the solid-state battery, and the determining that the solid-state battery is in a dormant state comprises: when the working current is less than a first current threshold and is maintained for a first time length, determining that the solid-state battery is in a dormant state.

[0010] In some embodiments, the first current threshold is 0.8 mA-1.5 mA; and / or, the first time length is 2 h-4 h.

[0011] In some embodiments, the working condition information comprises a pressure fluctuation value of the solid-state battery, and the determining that the solid-state battery is in a dormant state comprises: when the pressure fluctuation value is less than a first pressure threshold and is maintained for a second time length, determining that the solid-state battery is in a dormant state.

[0012] In some embodiments, the first pressure threshold is 0.04 MPa-0.06 MPa; and / or, the second time length is 0.5 h-1 h.

[0013] In some embodiments, the working condition information comprises a temperature rising speed of the solid-state battery, and the adjusting the pressure of the solid-state battery according to the running state comprises: when the temperature rising speed is higher than a first temperature rising speed threshold, determining that the solid-state battery is in an abnormal heat dissipation state; and depressurizing the solid-state battery.

[0014] In some embodiments, the first temperature rising speed threshold is 0.5 ℃ / min-0.8 ℃ / min.

[0015] In some embodiments, the depressurizing the solid-state battery comprises: controlling the solid-state battery to decrease from an initial pressure P0 to a first preset pressure value P1, wherein P0 and P1 satisfy:

[0016] 0≤P1 / P0≤m×a×C-b×H,

[0017] wherein m x a x C - b x H > 0, 0≤m≤1, 0≤a≤0.15, 0≤b≤0.01, C is the battery SOC, 0≤C≤1, H is the battery SOH, 0≤H≤1, and m is determined according to the chemical system of the solid-state battery.

[0018] In some embodiments, the working condition information further comprises: a starting state of the vehicle and a connection state of a charging port of the vehicle, and the adjusting the pressure of the solid-state battery according to the running state comprises: determining that the solid-state battery is in an activated state if the vehicle is in the starting state and / or the charging port of the vehicle is in the connection state; and performing pressure recovery on the solid-state battery.

[0019] In some embodiments, the performing pressure recovery on the solid-state battery comprises: controlling the solid-state battery to rise from the first preset pressure value P1 to the initial pressure P0.

[0020] In some embodiments, the performing pressure recovery on the solid-state battery comprises: controlling the solid-state battery to rise from the first preset pressure value P1 to a second preset pressure value P2 and maintain the pressure for a first preset time period, wherein the second preset pressure value P2 is greater than the initial pressure P0; and controlling the solid-state battery to fall from the second preset pressure value P2 to the initial pressure P0.

[0021] In some embodiments, the P2 and the P0 satisfy: 1≤P2 / P0≤2; and / or, the first preset time period is 1s-60s.

[0022] In some embodiments, the controlling the solid-state battery to rise from the first preset pressure value P1 to the second preset pressure value P2 comprises: controlling the solid-state battery to rise from the first preset pressure value P1 to the second preset pressure value P2 within a second preset time period, and the second preset time period is 1s-10s.

[0023] In some embodiments, the controlling the solid-state battery to fall from the second preset pressure value P2 to the initial pressure P0 comprises: controlling the solid-state battery to fall from the second preset pressure value P2 to the initial pressure P0 within a third preset time period, and the third preset time period is 1s-10s.

[0024] In a second aspect, the application provides a pressure regulation system of a solid-state battery, which is suitable for applying the pressure management method of the solid-state battery in the first aspect. The pressure regulation system comprises a box, a pressure regulation unit and a control unit. The solid-state battery is arranged in the box. The pressure regulation unit is configured to regulate the pressure applied to the solid-state battery. The control unit is configured to control the pressure regulation unit. The control unit is further configured to acquire working condition information of the solid-state battery, determine an operating state of the solid-state battery according to the working condition information, and regulate the pressure of the solid-state battery according to the operating state. The operating state comprises a dormant state, an activated state and an abnormal heat release state.

[0025] In some embodiments, the inner cavity of the box is provided with a pressure regulation member. The pressure regulation member divides the inner cavity of the box into a containing cavity and a pressurizing cavity. The solid-state battery is arranged in the containing cavity. The pressurizing cavity is configured to contain a pressure medium. The pressure regulation unit is configured to regulate the pressure medium in the pressurizing cavity to regulate the pressure applied to the solid-state battery by the pressure regulation member. The control unit controls the pressure regulation unit to regulate the pressure medium in the pressurizing cavity according to the operating state of the solid-state battery, so as to regulate the pressure applied to the solid-state battery by the pressure regulation member.

[0026] In a third aspect, the application provides a vehicle comprising the pressure regulation system of the solid-state battery in the second aspect. The vehicle further comprises a suspension. The suspension comprises a pressure regulation circuit. The pressure regulation circuit is in communication with the pressurizing cavity. The suspension constitutes at least part of the pressure regulation unit of the pressure regulation system. The control unit controls the pressure regulation circuit to regulate the pressure medium in the pressurizing cavity according to the operating state, so as to regulate the pressure applied to the solid-state battery by the pressure regulation member. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, hereinafter, a brief introduction will be given to the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application. Those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0028] FIG. 1 is a schematic diagram of a pressure regulation system of a solid-state battery according to an embodiment of the application;

[0029] FIG. 2 is a structural schematic diagram of a battery pack according to an embodiment of the application;

[0030] FIG. 3 is a logic diagram of a pressure management method of a solid-state battery according to an embodiment of the application;

[0031] FIG. 4 is a schematic diagram of pressure change of the solid-state battery according to an embodiment of the present application;

[0032] FIG. 5 is a flowchart of pressure management of the solid-state battery according to an embodiment of the present application.

[0033] Legend: 100-pressure regulation system; 1-battery pack; 11-box; 12-pressure regulation member; 13-housing cavity; 14-pressurizing cavity; 15-solid-state battery; 16-positive electrode port; 17-negative electrode port; 18-communication port; 19-detection device; 2-pressure regulation unit; 3-control unit; 4-vehicle control system. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0035] At present, the interface problem of the battery under the electrolyte system is not prominent. When the material expands and shrinks during the operation of the battery, the electrolyte can adapt to the volume change, and there is no disconnection of the physical electrical connection between the material and the electrolyte caused by the volume change. And the current battery using the electrolyte system adopts a graphite negative electrode with small expansion, and full SOC and SOH do not need to be continuously pressurized. But the solid-state battery is composed of inorganic solid materials, and needs to maintain continuous pressure during operation to ensure the contact and conduction of active particles.

[0036] However, because the electronic conductivity in the electrolyte of the solid-state battery is significantly higher than that of the electrolyte, the self-discharge of the solid-state battery is more serious. For example, the electronic conductivity of Li6PS5Cl material measured in the related technology is as high as 2x10 -10 S / cm, which will cause the self-discharge of the solid-state battery to be much higher than that of the battery using the electrolyte, so that the calendar life of the solid-state battery is much less than 10 years.

[0037] Therefore, the present application provides a pressure management method for a solid-state battery, which configures a management control logic to first acquire working condition information of the solid-state battery, determines the running state of the solid-state battery according to the working condition information, and then adjusts the pressure according to the running state of the solid-state battery. In this way, when the solid-state battery is in different states, it can provide a matching pressure to ensure that the solid-state battery has an electrical performance adapted to the state, which is beneficial to maximize the saving and utilization of the energy of the solid-state battery, prolong the service life of the solid-state battery, improve the reliability of the solid-state battery, and help to improve the user's experience of using the vehicle.

[0038] The pressure management method of the solid-state battery 15 of the first aspect of the present application is described below in combination with FIGS. 1-5.

[0039] The pressure management method of the solid-state battery 15 of the present embodiment can be used in the pressure regulation system 100 of the solid-state battery 15 of a vehicle. The vehicle can be a new energy vehicle or a hybrid vehicle, and the vehicle uses the solid-state battery 15 as an energy storage and supply device. The vehicle can include a vehicle body and the pressure regulation system 100 of the solid-state battery 15, and the pressure regulation system 100 is arranged in the vehicle body.

[0040] Referring to FIGS. 1 and 2, the pressure regulation system 100 can include a box body 11, a pressure regulation unit 2, and a control unit 3. The solid-state battery 15 can be arranged in the box body 11 and jointly form a battery pack 1 with the box body 11, so that the battery pack 1 is installed as an integrated modular structure. The pressure regulation unit 2 is used to regulate the pressure of the solid-state battery 15, where the pressure of the solid-state battery 15 refers to the pressure of the solid-state battery 15 from the outside (i.e., the pressure regulation unit 2). The pressure regulation unit 2 can apply pressure to the solid-state battery 15, and the control unit 3 is used to control the pressure regulation unit 2, thereby controlling the pressure applied to the solid-state battery 15 by the pressure regulation unit 2.

[0041] For example, a movable clamping plate can be arranged in the box body 11, and the clamping plate serves as a pressure regulation member 12 for applying pressure to the solid-state battery 15. The clamping plate can jointly clamp the solid-state battery 15 with the side wall of the box body 11. The pressure regulation unit 2 can be a motor having a telescopic transmission shaft. The motor drives the clamping plate to move by the extension and retraction of the transmission shaft, thereby regulating the pressure applied to the solid-state battery 15. Alternatively, the pressure regulation unit 2 can be one of various pressure cylinders such as a pneumatic cylinder, a hydraulic cylinder, and an electric cylinder. The piston of the pressure cylinder extends and retracts to drive the clamping plate to move, thereby regulating the pressure applied to the solid-state battery 15. Alternatively, a pressure cavity is arranged on the side of the clamping plate away from the solid-state battery 15 in the box body 11. The pressure regulation unit 2 can be a device that can provide a pressure medium such as a liquid supply device or a gas supply device. The pressure regulation unit 2 drives the clamping plate to move by injecting or extracting a gas or liquid as a pressure medium into the pressure cavity, thereby regulating the pressure applied to the solid-state battery 15. Of course, the present application does not limit this, and the pressure regulation unit 2 can also be other devices.

[0042] In combination with FIGS. 3-5, the pressure management method of the present embodiment can include the following steps:

[0043] S1, obtaining working condition information of the solid-state battery 15;

[0044] Here, the working condition information of the solid-state battery 15 can include the temperature, pressure of the solid-state battery 15, the voltage, working current, duration t of the solid-state battery 15, and the like, and the application is not limited to this. The above working condition information can be obtained by the detection device 19, wherein the detection device 19 can include a temperature detection device, a pressure detection device, and the like, and the temperature detection device and the pressure detection device are arranged in the battery pack 1 to detect the temperature and pressure of the solid-state battery 15. The detection device 19 can also include a current-voltage detection device, and the current-voltage detection device is connected to the positive electrode port 16 and the negative electrode port 17 of the battery pack 1 to detect the voltage and working current of the solid-state battery 15. In addition, the working condition information of the solid-state battery 15 can be obtained at a predetermined time interval, or the working condition information of the solid-state battery 15 can be obtained in real time. The detection device 19 can send the obtained working condition information to the control unit 3, and the control unit 3 processes the working condition information to generate an execution instruction and the like. The control unit 3 can be the vehicle control system 4, or can be an electronic control unit specially configured for the battery pack 1.

[0045] In addition, the working condition information can also include vehicle information, for example, the control unit 3 can also be connected with the vehicle control system 4 of the vehicle to transmit vehicle information, and the vehicle information can include the starting and shutdown state of the vehicle, the connection state of the vehicle charging interface, and the like.

[0046] It can be understood that, in the above working condition information, the working condition information collected by the battery management system (BMS) can include the pressure, voltage V, working current I, temperature, and duration t of the solid-state battery 15.

[0047] And the data obtained by performing mathematical operations on the collected initial data includes:

[0048] Battery state of charge (SOC), battery state of health (SOH), temperature rise rate AT, pressure fluctuation value AP. Among them, the determination method of SOC includes at least two kinds, one is for the battery with slope charge-discharge curve, the SOC of the battery is determined according to the stable open circuit voltage of the battery; The other is for the battery with long charge-discharge platform, the initial discharge capacity C0 of the battery is given, the discharge capacity of each full charge and discharge is updated, the difference between the cumulative charge and discharge capacity of the battery after full charge is calculated based on C0, the difference value is obtained by subtracting the self-discharge capacity (obtained by multiplying the storage time with the given self-discharge rate) during storage from the difference value, and the SOC of the battery is estimated by the ratio of the difference value to C0; For the battery state of health SOH, the initial SOH is set to 100%, and the SOH value of the battery during use is obtained by dividing the discharge capacity of the full charge and discharge by the initial rated capacity C0 of the battery; The temperature rise rate AT can be obtained by collecting the temperature and taking the first derivative with respect to time, and the pressure fluctuation value AP can be obtained by collecting the pressure and calculating the pressure difference in a fixed time interval.

[0049] S2, determine the operating state of the solid-state battery 15 according to the working condition information, the operating state including: sleep state, active state and abnormal heat release state;

[0050] The control unit 3 can calculate the battery state of charge SOC, the battery state of health SOH, the temperature rise rate AT, the pressure fluctuation value AP and the like according to the above-mentioned working condition information, determine whether the solid-state battery 15 is in one of the sleep state, the active state and the abnormal heat release state according to the calculation results, and provide a basis for subsequent execution of the pressure control strategy in the corresponding operating state.

[0051] S3, adjust the pressure of the solid-state battery 15 according to the operating state.

[0052] For example, when the control unit 3 determines that the solid-state battery 15 is in the sleep state, it can be considered that the solid-state battery 15 is in the standby state, at this time the vehicle does not need the solid-state battery 15 to discharge, in order to save energy, the control unit 3 can control the pressure adjusting unit 2 to perform pressure relief operation on the solid-state battery 15, reduce the pressure of the solid-state battery 15, and alleviate the self-discharge problem of the solid-state battery 15.

[0053] When the control unit 3 determines that the solid-state battery 15 is in the abnormal heat release state, in order to eliminate the safety hidden danger, the control unit 3 can control the pressure adjusting unit 2 to perform pressure relief operation on the solid-state battery 15, reduce the pressure of the solid-state battery 15, reduce the heat diffusion speed, reduce the heat release caused by the positive and negative short circuit, and avoid the safety risk caused by thermal runaway.

[0054] When the control unit 3 judges that the solid-state battery 15 is in the active state, it indicates that the vehicle needs the solid-state battery 15 to normally and stably supply power. At this time, the pressure adjusting unit 2 can be controlled by the control unit 3 to perform a pressure recovery operation on the solid-state battery 15, so as to increase the pressure of the solid-state battery 15, and ensure that the internal active particles of the solid-state battery 15 can realize good interface contact and electrical conduction in the circulation process, thereby realizing a higher degree of performance of the solid-state battery 15.

[0055] According to the pressure management method of the solid-state battery 15 provided in the embodiments of the present application, the management control logic is configured to first acquire the working condition information of the solid-state battery 15, determine the running state of the solid-state battery 15 according to the working condition information, and then adjust the pressure according to the running state of the solid-state battery 15. In this way, when the solid-state battery 15 is in different states, it can provide a matching pressure to ensure that the solid-state battery 15 has an electrical performance adapted to the state, which is beneficial to maximize the saving and utilization of the energy of the solid-state battery 15, prolong the service life of the solid-state battery 15, improve the reliability of the solid-state battery 15, and help improve the user's experience of using the vehicle.

[0056] In some embodiments, adjusting the pressure of the solid-state battery 15 according to the running state comprises: determining that the solid-state battery 15 is in a dormant state, and discharging the solid-state battery 15.

[0057] Specifically, when the solid-state battery 15 is in the dormant state, it can be considered that the solid-state battery 15 is currently in a standby state, for example, the vehicle has been turned off, and the solid-state battery 15 does not need to continue to discharge. At this time, in order to avoid waste of energy of the solid-state battery 15, the pressure adjusting unit 2 can be controlled by the control unit 3 to perform corresponding actions, reduce the pressure of the solid-state battery 15, increase the internal impedance of the solid-state battery 15, and inhibit the electrical conduction between the internal active particles of the solid-state battery 15, thereby alleviating the self-discharge problem of the solid-state battery 15 and saving the energy of the solid-state battery 15.

[0058] In some embodiments, the working condition information can include a working current I of the solid-state battery 15. The determination that the solid-state battery 15 is in the dormant state can include: when the working current is less than a first current threshold and is maintained for a first time length, determining that the solid-state battery 15 is in the dormant state.

[0059] The first current threshold value herein refers to the maximum current value of the self-discharge of the solid-state battery 15 in the dormant state. When the working current I is less than the first current threshold value and lasts for a first time length, it can be considered that the solid-state battery 15 is stably in the dormant state. In this way, by comparing the working current I with the first current threshold value and comparing the duration of the working current I with the first time length, it can be more accurately judged whether the solid-state battery 15 is in the dormant state, preventing misjudgment of the operating state of the solid-state battery 15 when the working current is intermittently lower than the first current threshold value due to unstable electrical performance of the solid-state battery 15 during the charging and discharging process. It can be understood that the first time length herein refers to the time length of the solid-state battery 15 in the state of the working current being less than the first current threshold value being greater than or equal to the first time length.

[0060] In some embodiments, the first current threshold value is 0.8mA-1.5mA. For example, the first current threshold value can be 0.8mA, 0.9mA, 1mA, 1.1mA, 1.2mA, 1.3mA, 1.4mA or 1.5mA, of course, the present application does not limit this, and the first current threshold value can be determined by statistical analysis of the working current I of the solid-state battery 15 multiple times entering the dormant state. In this way, it can be ensured that the self-discharge current of the solid-state battery 15 in the dormant state is as small as possible to avoid energy waste and maximize energy saving.

[0061] In some embodiments, the first time length is 2h-4h, and the first time length can be 2h, 2.2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h or 4h, of course, the present application does not limit this, and the first time length can be reasonably selected as needed. By setting the first time length to 2h-3.5h, it can be avoided that the first time length is too short, for example, less than 2h, the detection result is inaccurate; it can also be avoided that the first time length is too long, for example, greater than 3.5h, the current detection time is too long, and the improvement effect on the accuracy of the detection result is limited.

[0062] Alternatively, detecting the working current I of the solid-state battery 15 within the first time length can be real-time detection or detection at intervals of a preset period. The preset period can be 5min-30min, for example, the preset period can be 5min, 10min, 15min, 20min, 25min or 30min. Taking 3h as the first time length, for example, the working current of the solid-state battery 15 can be detected once every 5min within 3h. In this way, it can improve the accuracy of the detection result, and at the same time, compared with real-time detection, it can also reduce the number of detections and be easy to implement.

[0063] In some embodiments, the working condition information can further include a pressure fluctuation value ΔP of the solid-state battery 15. Accordingly, determining that the solid-state battery 15 is in the dormant state can include: when the pressure fluctuation value ΔP is less than a first pressure threshold value and is maintained for a second time length, determining that the solid-state battery 15 is in the dormant state.

[0064] It can be understood that the pressure fluctuation value ΔP here is the difference between the currently detected pressure value of the solid-state battery 15 and the average pressure value of the solid-state battery 15 in the dormant state, which can be determined by averaging a plurality of pressure values of the solid-state battery 15 in the dormant state.

[0065] Since the solid-state battery 15 changes in volume when working, and the volume change will affect the pressure of the solid-state battery 15, when the solid-state battery 15 is in the dormant state, the volume change of the solid-state battery 15 is small, and the pressure fluctuation is also small. In this embodiment, when the pressure fluctuation value is less than the first pressure threshold value and is maintained for a second time length, it is determined that the pressure of the solid-state battery 15 is relatively stable, and it is determined that the solid-state battery 15 has entered the dormant state. In this way, the judgment of the dormant state of the solid-state battery 15 is more accurate. Here, the second time length refers to the time length when the pressure fluctuation value of the solid-state battery 15 is less than the first pressure threshold value, which is greater than or equal to the second time length.

[0066] In some embodiments, the first pressure threshold value is 0.04MPa-0.06MPa, for example, the first pressure threshold value can be 0.04MPa, 0.05MPa or 0.06MPa, of course, the present application does not limit this, the first pressure threshold value can be determined by statistical analysis of the pressure fluctuation value when the solid-state battery 15 enters the dormant state multiple times. In this way, a reference value as small as possible is provided for the pressure fluctuation value of the solid-state battery 15 in the dormant state, which can ensure that the judgment of the dormant state of the solid-state battery 15 is more accurate.

[0067] In some embodiments, the second time length is 0.5h-1h. For example, the second time length can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1h, of course, the present application does not limit this, the second time length can be reasonably selected as needed. By setting the second time length to 0.5h-1h, it can avoid that the second time length is too short, for example, less than 0.5h, the detection result is not accurate; it can also avoid that the second time length is too long, for example, greater than 1h, the time length of the pressure fluctuation value is too long, and the effect of improving the accuracy of the detection result is limited.

[0068] Optionally, the pressure fluctuation value of the solid-state battery 15 in the first time length can be detected in real time or at intervals of a preset period. The preset period can be 1 minute to 15 minutes, for example, the preset period can be 1 minute, 2 minutes, 5 minutes, 10 minutes or 15 minutes. Taking 1 hour as the first time length, for example, the pressure of the solid-state battery 15 can be detected once every 2 minutes in 1 hour, and the pressure fluctuation value is calculated. In this way, the accuracy of the detection result can be improved, and the number of detections can be reduced compared to real-time detection, which is easy to implement.

[0069] In some embodiments, the working condition information can further include a temperature rise speed of the solid-state battery 15, and the adjusting the pressure of the solid-state battery 15 according to the running state comprises: determining that the solid-state battery 15 is in an abnormal heat dissipation state when the temperature rise speed AT is higher than a first temperature rise speed threshold; and discharging the pressure of the solid-state battery 15.

[0070] Specifically, when the temperature rise speed AT of the solid-state battery 15 is higher than the first temperature rise speed threshold, it indicates that the temperature rise speed AT of the solid-state battery 15 has exceeded the temperature rise speed in the normal stable working state. This situation can be caused by a short circuit of the solid-state battery 15 or an abnormality of the heat dissipation system. In order to improve safety, avoid explosion caused by thermal runaway, the control unit 3 can control the pressure adjusting unit 2 to discharge the pressure of the solid-state battery 15 at this time, increase the internal impedance of the solid-state battery 15, suppress the current conduction in the solid-state battery 15, reduce the heat diffusion speed, and reduce the heat dissipation of the solid-state battery 15. The loss caused by thermal runaway is avoided.

[0071] In some embodiments, the first temperature rise speed threshold is 0.5°C / min to 0.8°C / min. For example, the first temperature rise speed threshold is 0.5°C / min, 0.6°C / min, 0.7°C / min or 0.8°C / min, of course, the present application does not make any limitation on this, the first temperature rise speed threshold can be reasonably determined according to the temperature rise speed of the solid-state battery 15 when the thermal runaway occurs or other factors. In this way, it is avoided that the first temperature rise speed threshold is too small, for example, less than 0.5°C / min, which causes misjudgment of the abnormal heat dissipation state, and it is also avoided that the first temperature rise speed threshold is too large, for example, greater than 0.8°C / min, which cannot effectively suppress the temperature rise when discharging the pressure of the solid-state battery 15, causing thermal runaway.

[0072] In some embodiments, discharging the pressure of the solid-state battery 15 can include: controlling the solid-state battery 15 to decrease from an initial pressure P0 to a first preset pressure value P1, wherein P0 and P1 satisfy:

[0073] 0≤P1 / P0≤m×a×C-b×H,

[0074] m x a x C - b x H > 0, 0≤m≤1, 0≤a≤0.15, 0≤b≤0.01, C is the state of charge of the solid-state battery 15, 0≤C≤1, H is the state of health of the solid-state battery 15, 0≤H≤1, m can be determined according to the chemical system of the solid-state battery 15, and the chemical system of the solid-state battery 15 includes the expansion rate of the positive electrode material, the Young's modulus, the expansion rate of the negative electrode material, the positive and negative electrode surface density, the Young's modulus of the electrolyte, the thickness of the electrolyte layer, and the like. In this embodiment, the chemical system is mainly distinguished by the negative electrode main material. For example, when the negative electrode is lithium metal, 0≤m≤0.4; when the negative electrode is silicon-carbon or silicon negative electrode, 0.5≤m≤1; when the negative electrode is graphite, 0.3≤m≤0.8; when the negative electrode has small expansion and large hardness, the value of m is large; when the negative electrode has small expansion or small hardness, the value of m is relatively small.

[0075] wherein the initial pressure P0 can be the pressure required by the solid-state battery 15 in a normal working state, such as vehicle starting, driving or vehicle charging.

[0076] In some embodiments, the working condition information can further include: a starting state of the vehicle and a connection state of the vehicle charging port. Adjusting the pressure of the solid-state battery 15 according to the running state includes: determining that the solid-state battery 15 is in an activated state if the vehicle is in a starting state and / or the vehicle charging port is in a connected state; and performing pressure recovery on the solid-state battery 15.

[0077] It can be understood that when the vehicle is in a starting state, the solid-state battery 15 needs to discharge externally; when the vehicle charging port is in a connected state, the solid-state battery 15 needs to be charged. In the above two cases, the solid-state battery 15 needs to work normally, so it can be determined that the solid-state battery 15 is in an activated state. At this time, the pressure adjusting unit 2 controlled by the control unit 3 can perform pressure recovery on the solid-state battery 15 after pressure relief, so as to ensure that the active particles inside the solid-state battery 15 have good interface contact, better conduct electricity, and maximize the performance of the solid-state battery 15.

[0078] Further, determining that the vehicle is in a starting state can include: determining that the vehicle starting key is in a starting state, and the current of the solid-state battery 15 is greater than a second current threshold. The second current threshold can be 1.8-2.5 mA. That is, it indicates that the vehicle is starting, and the battery is about to enter an activated state, so the pressure recovery operation of the solid-state battery 15 can be started.

[0079] In some embodiments, performing pressure recovery on the solid-state battery 15 can include: controlling the solid-state battery 15 to rise from the first preset pressure value P1 to the initial pressure P0.

[0080] In this way, the solid-state battery 15 can have the pressure required for normal operation, so that the active particles inside the solid-state battery 15 have good interface contact during normal operation, so as to better conduct electricity and maximize the performance of the solid-state battery 15.

[0081] In some alternative embodiments, the control of the solid-state battery 15 to recover from the first preset pressure value P1 to the initial pressure P0 includes: controlling the solid-state battery 15 to rise from the first preset pressure value P1 to a second preset pressure value P2, and maintaining the pressure for a first preset time t1, wherein the second preset pressure value P2 is greater than the initial pressure P0; and controlling the solid-state battery 15 to decrease from the second preset pressure value P2 to the initial pressure P0.

[0082] That is, the operation of recovering the pressure of the solid-state battery 15 can be to first increase the pressure of the solid-state battery 15 from the first preset pressure value P1 after pressure relief to a second preset pressure value P2 greater than the initial pressure P0, maintain the pressure at the second preset pressure value P2 for a first preset time t1, and then decrease from the second preset pressure value P2 to the initial pressure P0. Since the second preset pressure value P2 is greater than the initial pressure P0, the solid-state battery 15 can recover to the state before pressure relief with higher efficiency, achieve good contact between the active particles inside, and reduce the internal resistance of the solid-state battery 15, thereby reducing the delay of the pressure recovery of the solid-state battery 15, so as to better and faster meet the power demand of the vehicle during the initial start-up. After the second preset pressure value P2 is maintained for a period of time, the pressure is decreased to the initial pressure P0, which can ensure more durable work of the solid-state battery 15 and reduce the power consumption speed.

[0083] In some embodiments, P2 and P0 satisfy: 1≤P2 / P0≤2, so as to avoid damage to the solid-state battery 15 when the second preset pressure value is too large, and to avoid the effect of recovering the pressure when the second preset pressure value is too small.

[0084] Optionally, the first preset time t1 is 1s-60s, for example, the first preset time t1 can be 1s, 5s, 10s, 20s, 30s, 40s, 50s or 60s, of course, the present application is not limited to this, the first preset time t1 can be reasonably selected within the above range as needed. In this way, the pressure fluctuation during the pressure recovery process can be reduced.

[0085] In some embodiments, the control of the solid-state battery 15 to rise from the first preset pressure value P1 to the second preset pressure value P2 includes: controlling the solid-state battery 15 to rise from the first preset pressure value P1 to the second preset pressure value P2 within a second preset time t2, and the second preset time t2 is 1s-10s.

[0086] For example, the second preset time length t2 can be 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, 10s, of course, the application is not limited to this, the second preset time length t2 can be reasonably selected within the above range as needed. In this way, it can be avoided that the pressure mutation causes the solid-state battery 15 to be damaged in the process of rising from the first preset pressure value P1 to the second preset pressure value P2 after pressure relief.

[0087] In some embodiments, the control of the solid-state battery 15 to decrease from the second preset pressure value P2 to the initial pressure P0 includes: controlling the solid-state battery 15 to decrease from the second preset pressure value P2 to the initial pressure P0 within a third preset time length t3, and the third preset time length t3 is 1s-10s.

[0088] For example, the third preset time length t3 can be 1s, 2s, 3s, 4s, 5s, 6s, 7s, 8s, 9s, 10s, of course, the application is not limited to this, the third preset time length t3 can be reasonably selected within the above range as needed. In this way, it can be avoided that the pressure mutation causes the solid-state battery 15 to be damaged in the process of decreasing from the second preset pressure value P2 to the initial pressure P0.

[0089] The pressure regulation system 100 of the solid-state battery 15 of the second aspect embodiment of the application is described below.

[0090] The pressure regulation system 100 of the embodiment is suitable for applying the pressure management method in the above embodiments.

[0091] Specifically, with reference to FIGS. 1 and 2, the pressure regulation system 100 can include: a box body 11, a pressure regulation unit 2, and a control unit 3. Wherein, the solid-state battery 15 can be arranged in the box body 11, and the box body 11 and the solid-state battery 15 together constitute a battery pack 1, so as to facilitate the installation of the battery pack 1 as an integrated modular structure. The pressure regulation unit 2 is used to regulate the pressure of the solid-state battery 15, and here the pressure of the solid-state battery 15 refers to the pressure of the solid-state battery 15 from the outside (i.e. the pressure regulation unit 2). The pressure regulation unit 2 can apply pressure to the solid-state battery 15, and the control unit 3 is used to control the pressure regulation unit 2, so as to control the pressure applied to the solid-state battery 15 by the pressure regulation unit 2.

[0092] For example, a movable clamping plate can be arranged in the box 11, and the clamping plate serves as the pressure adjusting element 12 for applying pressure to the solid-state battery 15. The clamping plate can be clamped with the side wall of the box 11 to hold the solid-state battery 15. The pressure adjusting unit 2 can be a motor with a telescopic transmission shaft. The motor drives the clamping plate to move by the extension and retraction of the transmission shaft, so as to adjust the pressure applied to the solid-state battery 15. Alternatively, the pressure adjusting unit 2 can be one of various pressure cylinders such as a pneumatic cylinder, a hydraulic cylinder, and an electric cylinder. The piston of the pressure cylinder extends and retracts to drive the clamping plate to move, so as to adjust the pressure applied to the solid-state battery 15. Alternatively, the clamping plate on the side away from the solid-state battery 15 in the box 11 is provided with a pressure cavity. The pressure adjusting unit 2 can be a device such as a liquid supply device or a gas supply device that can provide a pressure medium. The pressure adjusting unit 2 drives the clamping plate to move by injecting or extracting a gas or a liquid as a pressure medium into the pressure cavity, so as to adjust the pressure applied to the solid-state battery 15. Of course, the present application does not limit this, and the pressure adjusting unit 2 can also be other devices.

[0093] The control unit 3 is configured to control the pressure adjusting unit 2. The control unit 3 is also configured to obtain working condition information of the solid-state battery 15, determine an operating state of the solid-state battery 15 according to the working condition information, and adjust the pressure of the solid-state battery 15 according to the operating state.

[0094] According to the pressure adjusting system of the solid-state battery 15, the control unit 3 obtains the working condition information of the solid-state battery 15, determines the operating state of the solid-state battery 15 according to the working condition information, and then adjusts the pressure according to the operating state of the solid-state battery 15. In this way, the solid-state battery 15 can be provided with a matching pressure in different states to ensure that the solid-state battery 15 has an electrical performance adapted to the state, which is beneficial to maximize the saving and utilization of the energy of the solid-state battery 15, prolong the service life of the solid-state battery 15, improve the reliability of the solid-state battery 15, and help improve the user experience of the vehicle.

[0095] In some embodiments, referring to FIGS. 1 and 2, the solid-state battery 15 can be square, and the box 11 can also be square. The inner cavity of the box 11 is provided with the pressure adjusting element 12, which can be a movable clamping plate.

[0096] The pressure adjusting member 12 can divide the inner cavity of the box body 11 into a containing cavity 13 and a pressurizing cavity 14. The containing cavity 13 can be used to contain the solid-state battery 15, and the pressurizing cavity 14 is used to contain a pressure medium, which can be a gas, a liquid, or the like. For example, the box body 11 can include a bottom plate, a top plate, and a plurality of side plates. The plurality of side plates are arranged around the periphery of the bottom plate. The bottom plate and the top plate are respectively located at two ends of the side plates. The pressure adjusting member 12 is arranged in parallel between the bottom plate and the top plate. The pressure adjusting member 12 and the bottom plate define the containing cavity 13. The pressure adjusting member 12 and the top plate define the pressurizing cavity 14. The cavity wall of the pressurizing cavity 14 is further provided with a communication port 18 which communicates the pressurizing cavity 14 with an external pipeline.

[0097] The pressure adjusting unit 2 is used to adjust the pressure medium in the pressurizing cavity 14, so as to adjust the pressure applied by the pressure adjusting member 12 to the solid-state battery 15. The control unit 3 controls the pressure adjusting unit 2 to adjust the pressure medium in the pressurizing cavity 14 according to the operating state of the solid-state battery 15, so as to adjust the pressure applied by the pressure adjusting member 12 to the solid-state battery 15.

[0098] It can be understood that, due to the uniform distribution of the pressure medium in the pressurizing cavity 14, the pressure medium can drive the pressure adjusting member 12 to move as a whole. In this way, the pressure adjusting member 12 can uniformly increase or decrease the pressure of each region of the solid-state battery 15, so as to avoid the uneven internal pressure of the solid-state battery 15, and is beneficial to improve the charge and discharge performance of the solid-state battery 15.

[0099] In a specific example, the pressure adjusting member 12 is configured to move relative to the box body 11 under the action of the pressure medium, in other words, the pressure adjusting member 12 is movable relative to the box body 11. When the pressure adjusting member 12 moves relative to the box body 11, the volumes of the pressurizing cavity 14 and the containing cavity 13 change at the same time. For example, when the pressure adjusting member 12 moves towards the side of the pressurizing cavity 14, the pressurizing cavity 14 shrinks and the containing cavity 13 becomes larger. When the pressure adjusting member 12 moves towards the side of the containing cavity 13, the containing cavity 13 shrinks and the pressurizing cavity 14 becomes larger.

[0100] A vehicle of a third aspect embodiment of the application is described below.

[0101] The vehicle of the embodiment can be a new energy vehicle or a hybrid vehicle. The vehicle can include a vehicle body, the pressure adjusting system 100 of the solid-state battery 15 of the above embodiment, and a suspension. The pressure adjusting system 100 is arranged on the vehicle body.

[0102] The suspension can constitute at least part of the pressure regulating unit 2, and can be an air suspension or a hydraulic suspension. The suspension can include a pressure regulating circuit in communication with the pressurized cavity 14, which adjusts the pressure of the solid-state battery 15 according to the operating state, including: adjusting the pressure medium in the pressurized cavity 14 through the pressure regulating circuit to drive the pressure regulating piece 12 to move to adjust the pressure of the solid-state battery 15 according to the operating state. For example, the cavity wall of the pressurized cavity 14 can be provided with a communication port 18, and the pressure regulating circuit can inject pressure medium into the pressurized cavity 14 through the communication port 18 to increase the pressure in the pressurized cavity 14, thereby increasing the pressure of the pressure regulating piece 12 on the solid-state battery 15; or the pressure medium in the pressurized cavity 14 can also flow into the pressure regulating circuit through the communication port 18, so that the pressure in the pressurized cavity 14 decreases, thereby reducing the pressure of the pressure regulating piece 12 on the solid-state battery 15.

[0103] That is, in the vehicle of the present embodiment, the pressure regulating circuit of the suspension is communicated with the pressurized cavity 14 of the battery pack 1, achieving the purpose of regulating the pressure of the solid-state battery 15 by the pressure regulating circuit of the suspension. On the one hand, the pressure of the solid-state battery 15 can be adaptively adjusted according to the state of the solid-state battery 15 to ensure good interfacial contact and electrical conduction of the active particles inside the solid-state battery 15 during the cycle process, achieving a high degree of performance, thereby making the charging and discharging process of the solid-state battery 15 more stable and reliable, and greatly improving the electrical performance; on the other hand, since the suspension of the vehicle and the battery pack 1 share the pressure regulating circuit, the integration of the vehicle can be improved, and the pressure supply device for the solid-state battery 15 can be omitted, which can reduce redundant components in the design of the vehicle, simplify the design, reduce the cost, and greatly improve the utilization rate of the chassis volume.

[0104] In addition, the vehicle of the present embodiment can increase the energy density by using the solid-state battery 15 as the power source, which can increase the endurance of the vehicle and improve the user experience. By setting the pressure regulating system 100 in the above embodiment, the working life of the solid-state battery 15 is longer, which can improve the reliability and endurance of the vehicle.

[0105] Optionally, the pressure regulating circuit can comprise a medium container, a medium driving device, a plurality of dampers and an electronic control unit. The medium container is used to store pressure medium, and the medium container is in communication with the pressurizing cavity 14 and the dampers respectively, so that the suspension and the battery pack 1 share the medium container, which can provide pressure medium for the dampers of the suspension to ensure the normal damping function of the dampers, and also provide pressure medium for the pressurizing cavity 14 of the battery pack 1 to regulate the pressure of the battery pack 1. When the suspension is a hydraulic suspension, the medium container can be a liquid storage tank, and the pressure medium is hydraulic oil, and the medium driving device is a hydraulic pump; when the suspension is an air suspension, the medium container is an air storage tank, the pressure medium is compressed air, and the medium driving device is an air compressor.

[0106] Further, adjusting the pressure of the solid-state battery 15 according to the operating state can comprise: controlling the pressure medium to flow back from the pressurizing cavity 14 to the pressure regulating circuit for pressure relief; or controlling the pressure medium to be injected from the pressure regulating circuit to the pressurizing cavity 14 for pressure recovery.

[0107] That is, when the solid-state battery 15 enters the dormant state or the abnormal heating state, the control unit 3 controls the medium driving device to drive the pressure medium to flow from the pressurizing cavity 14 of the battery pack 1 to the pressure regulating circuit, for example, into the medium container, thereby reducing the pressure applied to the solid-state battery 15; when the solid-state battery 15 enters the activated state, the control unit 3 controls the medium driving device to drive the pressure medium to be injected from the pressure regulating circuit to the pressurizing cavity 14 of the battery pack 1, thereby increasing the pressure applied to the solid-state battery 15 to achieve pressure recovery. In this way, the operation is relatively simple and easy to implement.

[0108] Some specific embodiments of the solid-state battery 15 and its pressure management method are given below.

[0109] Embodiment One

[0110] Battery preparation: In this embodiment, the solid-state battery 15 uses ternary material LiNi 0.9 Co 0.05 Mn 0.05 O2 as the positive electrode, Li6PS5Cl as the solid-state electrolyte layer, and pure silicon negative electrode as the negative electrode. The positive electrode, negative electrode and electrolyte layer are prepared into a single battery in a laminated manner. A plurality of single batteries are arranged in a laminated manner (and the side surfaces of adjacent single batteries in the thickness direction are in contact to ensure that the adjacent two single batteries have the maximum contact area), and the battery pack 1 is assembled in a manner that the largest side surface of the solid-state battery 15 is parallel to the pressure regulating member 12 in the box 11.

[0111] The battery pack 1 is cycled in constant pitch mode at an initial pressure of 20 MPa. When discharged to 90% SOC, the electronic control unit detects that the operating current of the solid-state battery 15 is 0 A, and the time during which it is equal to 0 A reaches 3 hours, at which time the battery pressure is 27 MPa, and the time during which the battery pressure fluctuation value ΔP≤0.05 MPa reaches 0.5 h, at which time it is determined that the battery enters a stable dormant state. Subsequently, the electronic control unit sends a command to adjust the pressure applied to the solid-state battery 15 to P1=3.6 MPa by the pressure control unit 3. After the solid-state battery 15 has been maintained at a pressure of 3.6 MPa for a period of time, the electronic control unit detects that the vehicle start key is in the active state, at which time the electronic control unit adjusts the pressure applied to the solid-state battery 15 from 3.6 MPa to 54 MPa in 10 s by the pressure control unit 3, the pressure is maintained at 54 MPa for 60 s, and then the pressure is reduced to 27 MPa in 10 s. The battery then continues to work in constant pitch at this pressure.

[0112] Example Two

[0113] The battery in this example is prepared differently from example 1 in that the negative electrode uses lithium metal.

[0114] The positive electrode, the negative electrode, and the electrolyte layer are prepared into a battery in a laminated manner. The battery is cycled in constant pressure mode (the distance between the battery clamps is adjusted in real time according to the constant pressure requirement) at an initial pressure of 2 MPa. When discharged to 20% SOC, the electronic control unit detects that the operating current of the solid-state battery 15 is equal to 1 mA, and the time during which it is equal to 1 mA reaches 4 h, and the time during which the battery pressure fluctuation value ΔP≤0.05 MPa reaches 1 h, at which time it is determined that the battery enters a stable dormant state.

[0115] Subsequently, the electronic control unit sends a command to adjust the pressure applied to the solid-state battery 15 to 0 MPa by the pressure control unit 3. After the solid-state battery 15 has been maintained at a pressure of 0 MPa for a period of time, the electronic control unit detects that the charging interface is connected, indicating that the battery will enter a charging state, at which time the electronic control unit adjusts the pressure applied to the solid-state battery 15 to 2 MPa in 5 s by the pressure control unit 3, and after the solid-state battery 15 is stable at a pressure of 2 MPa for 10 s, the pressure program ends and the vehicle can enter the working state.

[0116] Example Three

[0117] The battery in this example is prepared differently from example 1 in that the negative electrode uses a silicon-carbon negative electrode.

[0118] The positive electrode, the negative electrode and the electrolyte layer are prepared into a solid-state battery 15 in a laminated manner. The solid-state battery 15 is cycled in a constant pitch mode under an initial pressure of 5 MPa. When discharged to 10% SOC, the electronic control unit detects that the working current of the solid-state battery 15 is equal to 0.01 mA, the 0.01 mA holding time reaches 3 hours, and the battery pressure fluctuation value AP is less than or equal to 0.05 MPa for 1 hour, at which time the battery pressure is 5.5 MPa. Subsequently, the electronic control unit sends a command to adjust the pressure applied to the solid-state battery 15 to 0.05 MPa through the pressure control unit 3. When the solid-state battery 15 maintains the pressure of 0.5 MPa for a period of time, the electronic control unit detects that the vehicle start key is in the active state, at which time the electronic control unit adjusts the pressure applied to the solid-state battery 15 to 10 MPa within 5 seconds through the pressure control unit 3, maintains this pressure for 30 seconds, and then adjusts the pressure back to 5.5 MPa within 2 seconds. Then the battery continues to maintain the constant pitch operation under this pressure.

[0119] Example Four

[0120] The battery preparation in this example is substantially the same as in Example 1, except that the pressure management method is different. In this example, during the operation of the solid-state battery 15, it is detected that the temperature rise rate of the solid-state battery 15 reaches 0.6°C / s, it is determined that the solid-state battery 15 enters an abnormal exothermic state, the battery pressure is adjusted to 0 MPa, and the pressure relief is completed.

[0121] Example Five

[0122] The battery preparation in this example is different from Example One in that the negative electrode is a graphite negative electrode.

[0123] The positive electrode, the negative electrode and the electrolyte layer are prepared into a solid-state battery 15 in a laminated manner. The solid-state battery 15 is cycled in a constant pitch mode under an initial pressure of 9 MPa. When discharged to 95% SOC, the electronic control unit detects that the working current of the solid-state battery 15 is equal to 0.01 mA, the 0.01 mA holding time reaches 3 hours, and the battery pressure fluctuation value AP is less than or equal to 0.05 MPa for 1 hour, at which time the battery pressure is 9.5 MPa. Subsequently, the electronic control unit sends a command to adjust the pressure applied to the solid-state battery 15 to 0.4 MPa through the pressure control unit 3. When the solid-state battery 15 maintains the pressure of 0.4 MPa for a period of time, the electronic control unit detects that the vehicle start key is in the active state, at which time the electronic control unit adjusts the pressure applied to the solid-state battery 15 to 10 MPa within 5 seconds through the pressure control unit 3, maintains this pressure for 5 seconds, and then adjusts the pressure back to 9.5 MPa within 2 seconds. Then the battery continues to maintain the constant pitch operation under this pressure.

[0124] Comparative Example One

[0125] The battery in Comparative Example 1 was prepared in the same manner as in Example 1, except that the solid-state battery 15 was kept in the working mode with constant gap pressure during working and storage at rest, and was not adjusted to the stable dormant state when the solid-state battery 15 was not working.

[0126] The inventors of the present application respectively conducted self-discharge tests and cycle life tests on the solid-state batteries 15 in Examples 1 to 4 and Comparative Example 1, and obtained the test results shown in Table 1 and Table 2.

[0127] Table 1: Self-discharge test results

[0128] Table 2: Battery cycle performance test results

[0129] It should be noted that the test method for the self-discharge test is as follows: the battery pack 1 in Examples 1 to 3 and 5 was stored after entering the dormant state at 100% SOC, and the experimental conditions were that the battery in the dormant state was stored at 45°C for 28 days. The ratio of the remaining capacity of the battery after storage to the initial capacity, i.e. the capacity remaining rate, and the ratio of the maximum discharge capacity after 3 times of charge and discharge to the initial capacity, i.e. the capacity recovery rate, were recorded. The capacity remaining rate and the capacity recovery rate were used to determine the self-discharge performance of the battery. The battery in Comparative Example 1 was stored at 45°C for 28 days after being adjusted to 100% SOC in the constant gap state and keeping the pressure at the end of charging. The capacity remaining rate and the capacity recovery rate after storage were tested.

[0130] The cycle life test method is as follows: the battery pack 1 in Examples 1 to 3 and 5 was charged at 1C and discharged at 1C, and was stored at 100% SOC for 2 days after 10 cycles. The storage time and temperature of Examples 1 to 3 and Comparative Example 1 were the same, except that the battery pack 1 in Examples 1 to 3 entered the dormant state through pressure adjustment during storage, while the battery pack 1 in Comparative Example 1 did not enter the dormant state through pressure adjustment.

[0131] Comparative analysis of Table 1 shows that the battery pack 1 in Examples 1 to 3 and 5 of the present application has a capacity remaining rate and a capacity recovery rate superior to that of the battery pack 1 in Comparative Example 1, because the battery was adjusted in pressure during the dormant state.

[0132] Comparative analysis of Table 2 shows that the battery pack 1 in Examples 1 to 3 and 5 of the present application has a battery cycle performance superior to that of the battery pack 1 in Comparative Example 1, because the battery was adjusted in pressure during the dormant state.

[0133] In summary, the pressure management method of the solid-state battery 15 in the embodiments of the present application can provide a matching pressure for the solid-state battery 15 in the dormant state to ensure that the solid-state battery 15 has an electrical performance adapted to the state, which is beneficial to maximize the saving and utilization of the energy of the solid-state battery 15, prolong the service life of the solid-state battery 15, improve the reliability of the solid-state battery 15, and help improve the user's experience of using the vehicle.

[0134] The embodiments or implementations in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be mutually referred to.

[0135] It should be noted that the embodiments referred to in the specification as "one embodiment", "an embodiment", "exemplary embodiment", "some embodiments" and the like can include specific features, structures or characteristics, but not necessarily every embodiment includes the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure or characteristic is described in combination with an embodiment, it is within the knowledge of those skilled in the art to realize such feature, structure or characteristic in combination with other embodiments that are explicitly or implicitly described.

[0136] In general, the terms should be understood at least partly by the context of use. For example, at least partly according to the context, the term "one or more" used in the specification can be used to describe any feature, structure or characteristic of singular meaning, or can be used to describe a combination of features, structures or characteristics of plural meaning. Similarly, at least partly according to the context, terms such as "a" or "said" can be understood to convey singular usage or to convey plural usage.

[0137] It should be readily understood that "on", "above" and "over" in the present disclosure should be interpreted in the broadest way, so that "on" not only means "directly on", but also includes the meaning of "on" with intermediate features or layers therebetween, and "above" or "over" not only includes the meaning of "above" or "over", but also can include the meaning of "above" or "over" without intermediate features or layers therebetween (i.e. directly on).

[0138] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and such modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of pressure management of a solid state battery (15) characterized by, The pressure management method comprises the following steps: Obtaining working condition information of the solid-state battery (15); Determining an operating state of the solid-state battery (15) according to the working condition information, the operating state comprising: a dormant state, an activated state and an abnormal heat dissipation state; Adjusting the pressure of the solid-state battery (15) according to the operating state.

2. The pressure management method of a solid state battery (15) according to claim 1, characterized in that, The adjusting the pressure of the solid-state battery (15) according to the operating state comprises: Determining that the solid-state battery (15) is in the dormant state; Performing pressure relief on the solid-state battery (15).

3. The pressure management method of a solid state battery (15) according to claim 2, characterized in that, The working condition information comprises a working current of the solid-state battery (15), and the determining that the solid-state battery (15) is in the dormant state comprises: When the working current is less than a first current threshold value and is maintained for a first time length, it is determined that the solid-state battery (15) is in the dormant state.

4. The pressure management method of a solid state battery (15) according to claim 3, characterized in that, The first current threshold value is 0.8 mA-1.5 mA; and / or the first time length is 2 h-4 h.

5. The pressure management method of a solid state battery (15) according to any one of claims 2-4, characterized in that, The working condition information comprises a pressure fluctuation value of the solid-state battery (15), and the determining that the solid-state battery (15) is in the dormant state comprises: When the pressure fluctuation value is less than a first pressure threshold value and is maintained for a second time length, it is determined that the solid-state battery (15) is in the dormant state.

6. The pressure management method of a solid-state battery (15) according to claim 5, characterized in that, The first pressure threshold value is 0.04 MPa-0.06 MPa; and / or the second time length is 0.5 h-1 h.

7. The pressure management method of a solid state battery (15) according to any one of claims 1 - 6, characterized by, The working condition information comprises a temperature rising speed of the solid-state battery (15), and the adjusting the pressure of the solid-state battery (15) according to the operating state comprises: When the temperature rising speed is higher than a first temperature rising speed threshold value, it is determined that the solid-state battery (15) is in the abnormal heat dissipation state; Performing pressure relief on the solid-state battery (15).

8. The pressure management method of a solid-state battery (15) according to claim 7, characterized in that, The first temperature rising speed threshold value is 0.5 ℃ / min-0.8 ℃ / min.

9. The pressure management method of a solid state battery (15) according to any one of claims 2-8, characterized in that, The performing pressure relief on the solid-state battery (15) comprises: Controlling the solid-state battery (15) to decrease from an initial pressure P0 to a first preset pressure value P1, wherein P0 and P1 satisfy: 0≤P1 / P0≤m×a×C-b×H, wherein m×a×C-b×H>0, 0≤m≤1, 0≤a≤0.15, 0≤b≤0.01, C is a battery SOC, 0≤C≤1, H is a battery SOH, 0≤H≤1, and m is determined according to a chemical system of the solid-state battery (15).

10. The pressure management method of a solid-state battery (15) according to claim 9, characterized in that, The working condition information further comprises: a starting state of a vehicle and a connection state of a vehicle charging port, and the adjusting the pressure of the solid-state battery (15) according to the operating state comprises: If the vehicle is in the starting state and / or the vehicle charging port is in the connection state, it is determined that the solid-state battery (15) is in the activated state; Performing pressure recovery on the solid-state battery (15).

11. The pressure management method of a solid-state battery (15) according to claim 10, characterized in that, The performing pressure recovery on the solid-state battery (15) comprises: Controlling the solid-state battery (15) to increase from the first preset pressure value P1 to the initial pressure P0.

12. The pressure management method of a solid-state battery (15) according to claim 10, characterized in that, The performing pressure recovery on the solid-state battery (15) comprises: control the solid-state battery (15) to increase from the first preset pressure value P1 to a second preset pressure value P2, and maintain the pressure for a first preset time period, wherein the second preset pressure value P2 is greater than the initial pressure P0; control the solid-state battery (15) to decrease from the second preset pressure value P2 to the initial pressure P0.

13. The pressure management method of a solid-state battery (15) according to claim 12, characterized in that, The P2 and the P0 satisfy: 1≤P2 / P0≤2; and / or, the first preset time period is 1s-60s.

14. The pressure management method of a solid-state battery (15) according to claim 12, characterized in that, The control of the solid-state battery (15) to increase from the first preset pressure value P1 to a second preset pressure value P2 includes: control the solid-state battery (15) to increase from the first preset pressure value P1 to a second preset pressure value P2 within a second preset time period, and the second preset time period is 1s-10s.

15. The pressure management method of a solid state battery (15) according to any one of claims 12-14, characterized by, The control of the solid-state battery (15) to decrease from the second preset pressure value P2 to the initial pressure P0 includes: control the solid-state battery (15) to decrease from the second preset pressure value P2 to the initial pressure P0 within a third preset time period, and the third preset time period is 1s-10s.

16. A pressure regulating system (100) of a solid state battery (15) adapted to apply the pressure management method of any one of claims 1-15, characterized in that, The pressure regulation system (100) comprises a box body (11), a pressure regulation unit (2) and a control unit (3), the solid-state battery (15) is arranged in the box body (11), the pressure regulation unit (2) is used for regulating the pressure applied to the solid-state battery (15), and the control unit (3) is used for controlling the pressure regulation unit (2); The control unit (3) is also used for acquiring working condition information of the solid-state battery (15), determining an operating state of the solid-state battery (15) according to the working condition information, and regulating the pressure of the solid-state battery (15) according to the operating state, wherein the operating state includes a dormant state, an activated state and an abnormal heat dissipation state.

17. The pressure regulation system (100) of the solid-state battery (15) according to claim 16, characterized in that, An inner cavity of the box body (11) is provided with a pressure regulation member (12), the inner cavity of the box body (11) is divided into a containing cavity (13) and a pressurizing cavity (14) by the pressure regulation member (12), the solid-state battery (15) is arranged in the containing cavity (13), and the pressurizing cavity (14) is used for containing a pressure medium, The pressure regulation unit (2) is used for regulating the pressure medium in the pressurizing cavity (14) to regulate the pressure applied to the solid-state battery (15) by the pressure regulation member (12); The control unit (3) controls the pressure regulation unit (2) to regulate the pressure medium in the pressurizing cavity (14) according to the operating state of the solid-state battery (15), so as to regulate the pressure applied to the solid-state battery (15) by the pressure regulation member (12).

18. A vehicle characterized by comprising: including The pressure regulation system (100) of the solid-state battery (15) according to claim 16 or 17; A suspension, the suspension comprising a pressure regulation circuit, the pressure regulation circuit being in communication with the pressurizing cavity (14), and the suspension constituting at least part of the pressure regulation unit (2) of the pressure regulation system (100); The control unit (3) adjusts the pressure medium in the pressurizing cavity (14) by controlling the pressure regulating circuit according to the operating state, so as to adjust the pressure applied by the pressure regulating member (12) to the solid-state battery (15).

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