Power supply device and energy storage system

Abstract

The application discloses a power supply device, comprising: a battery; a liquid supplement unit, the liquid supplement unit comprising a first liquid reservoir and a second liquid reservoir in fluid communication with the battery respectively, the first liquid reservoir storing a weak solvent-based electrolyte, and the second liquid reservoir storing a strong solvent compensation liquid; a monitoring unit for monitoring the working condition of the battery in real time and generating corresponding working condition information; and a master control unit in communication connection with the liquid supplement unit and the monitoring unit respectively, for acquiring the working condition information from the monitoring unit, and controlling the liquid supplement unit to input the weak solvent-based electrolyte or the strong solvent compensation liquid to the battery according to the working condition information, so as to supplement the battery. The application also discloses an energy storage system applying the above power supply device.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a power supply device and an energy storage system. Background Art

[0002] Sodium-ion battery packs can be used in energy storage systems. Conventional sodium-ion cells in sodium-ion battery packs typically use a fixed electrolyte formulation, but this can easily lead to increased pressure differentials within the pack. The temperature sensitivity of sodium-ion batteries increases the viscosity of the electrolyte at low temperatures, which in turn increases the pressure differential within the pack.

[0003] When the pressure difference within the sodium-ion battery pack increases, on the one hand, the available capacity of the sodium-ion battery pack will be reduced due to the barrel effect, thereby reducing the cycle life of the sodium-ion battery pack; on the other hand, it is very easy to cause overcharging of batteries with relatively high SOC in the sodium-ion battery pack and over-discharging of batteries with relatively low SOC during the charging and discharging process.

[0004] Therefore, how to effectively reduce the pressure difference within the sodium-ion battery pack from the root, improve the cycle life of the sodium-ion battery pack, and at the same time avoid overcharging and over-discharging of the sodium-ion battery caused by the increase in the pressure difference within the sodium-ion battery pack is an urgent problem that the battery industry needs to solve. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention specifically provides the following technical solutions.

[0006] The present invention provides a power supply device, comprising:

[0007] Battery;

[0008] a fluid replenishing unit, the fluid replenishing unit comprising a first reservoir and a second reservoir respectively in fluid communication with the battery, the first reservoir storing a weak solvent-based electrolyte, and the second reservoir storing a strong solvent compensation solution;

[0009] A monitoring unit, configured to monitor the operating condition of the battery in real time and generate corresponding operating condition information;

[0010] A main control unit, wherein the main control unit is communicatively connected to the rehydration unit and the monitoring unit, respectively, and is used to obtain the operating condition information from the monitoring unit, and control the rehydration unit to input the weak solvent-based electrolyte or the strong solvent compensation solution into the battery according to the operating condition information to rehydrate the battery.

[0011] Optionally, the operating condition of the battery includes at least one of electrolyte concentration, voltage, temperature, and SOC of the battery;

[0012] The monitoring unit includes an electrolyte monitoring unit and a BMS; the electrolyte monitoring unit is used to monitor the electrolyte concentration of the battery, and the BMS is used to monitor at least one of the voltage, temperature and SOC of the battery.

[0013] Optionally, the rehydration unit further includes a microfluidic pump assembly, which is fluidically connected to the battery, the first reservoir and the second reservoir, and is used to input the weak solvent-based electrolyte or the strong solvent compensation liquid into the battery under the control of the main control unit.

[0014] Optionally, there are multiple batteries; the operating condition of the battery further includes a maximum voltage difference among the multiple batteries, where the maximum voltage difference is the maximum value of the difference between the voltage of each battery in the multiple batteries and the average voltage of the multiple batteries;

[0015] The main control unit is configured to determine a battery to be replenished among the multiple batteries according to the maximum pressure difference.

[0016] Optionally, the SOC of the battery includes an average SOC of the plurality of batteries and a single cell SOC of each battery in the plurality of batteries;

[0017] The main control unit is further used to: when the single cell SOC of the battery to be replenished is greater than the average SOC of the multiple batteries, determine that the weak solvent-based electrolyte needs to be replenished to the battery to be replenished; when the single cell SOC of the battery to be replenished is less than the average SOC of the multiple batteries, determine that the strong solvent compensation liquid needs to be replenished to the battery to be replenished.

[0018] Optionally, the operating condition of the battery further includes a maximum temperature difference of the multiple batteries, where the maximum temperature difference is a temperature difference between a battery with the highest temperature and a battery with the lowest temperature among the multiple batteries;

[0019] The main control unit is further configured to calculate the amount of fluid to be replenished for the battery to be replenished according to the following replenishment formula:

[0020] Q=k1·ΔV·e(-Ea / (R·Tavg))+k2·ΔT;

[0021] Wherein, Q is the amount of fluid replacement, ΔV is the maximum pressure difference, ΔT is the maximum temperature difference, E a is the preset activation energy of the electrolyte, R is the preset ideal gas constant, Tavg is the preset ideal average temperature of multiple batteries, k1 is the preset pressure difference weight coefficient, and k2 is the preset temperature difference weight coefficient.

[0022] Optionally, the main control unit is further configured to determine a rehydration effect after rehydrating the battery to be rehydrated, and adjust a pressure difference weight coefficient and / or a temperature difference weight coefficient in the rehydration formula according to the rehydration effect;

[0023] Wherein, the fluid replenishment effect includes at least one of a voltage regulation effect, a temperature regulation effect, and an electrolyte ion concentration compensation effect;

[0024] The voltage regulation effect is a ratio of a change in the pressure difference of the battery to be replenished after replenishment to a change in the pressure difference before replenishment, wherein the change in the pressure difference after replenishment is a change in the pressure difference between the voltage of the battery to be replenished after this replenishment and an average voltage of the multiple batteries, and the pressure difference before replenishment is a pressure difference between the voltage of the battery to be replenished before this replenishment and the average voltage of the multiple batteries;

[0025] The temperature regulation effect is the ratio of the change in the maximum temperature difference of the multiple batteries after the current fluid replenishment to the maximum temperature difference of the multiple batteries before the current fluid replenishment;

[0026] The electrolyte ion concentration compensation effect is the ratio of the change in the electrolyte ion concentration of the battery to be replenished after the current replenishment to the electrolyte ion concentration of the battery to be replenished before the current replenishment.

[0027] Optionally, the main control unit is specifically configured to adjust the pressure difference weight coefficient and / or the temperature difference weight coefficient in the fluid replenishment formula according to the following formula:

[0028] K1'=(1-Y1) / [(1-Y1)+(1-Y2)]·X·K1;

[0029] K2'=(X-K1')·K2;

[0030] Among them, Y1 is the voltage regulation effect, Y2 is the temperature regulation effect, X is the electrolyte ion concentration compensation effect; K1 is the pressure difference weight coefficient before adjustment, K2 is the temperature difference weight coefficient before adjustment, K1' is the pressure difference weight coefficient after adjustment, and K2' is the temperature difference weight coefficient after adjustment.

[0031] Optionally, the power supply device further includes a recovery unit, which is connected to the multiple batteries and the microfluidic pump assembly respectively, and is used to receive and decompose undecomposed electrolyte in the battery to be replenished after replenishment.

[0032] In addition, the present invention also provides an energy storage system, comprising the power supply device described above.

[0033] The above technical solution monitors the battery's operating condition in real time and automatically replenishes the battery with either a weak-solvent electrolyte or a strong-solvent compensation solution based on this information, eliminating the need for manual intervention. Automatic battery replenishment reduces the battery's voltage differential, extending its cycle life while also preventing overcharge and over-discharge caused by increased voltage differentials within the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic structural diagram of a power supply device provided in an embodiment of the present invention.

[0036] Figure 2 A schematic diagram of an application scenario of the power supply device provided by an embodiment of the present invention.

[0037] Figure 3 This is a flow chart of a working method of a power supply device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0039] The specific embodiments described herein are merely used to explain the present application and are not intended to limit the present application.

[0040] Although the steps in the flowcharts of the embodiments of the present invention are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders.

[0041] The terms "or", "and / or", "including at least one of the following", etc. used in this application may be interpreted as inclusive, or mean any one or any combination. For example, "including at least one of the following: A, B, C" means "including any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". For another example, "A, B or C" or "A, B and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". An exception to this definition will only occur when the combination of elements, functions or operations is inherently mutually exclusive in some way.

[0042] In the following description, the suffixes such as "unit" and "device" used to represent elements are only used to facilitate the description of the present application and have no specific meaning. Therefore, "unit" and "device" can be used interchangeably.

[0043] See Figure 1 According to one aspect of the present application, a power supply device is provided, comprising:

[0044] Battery 1.

[0045] The rehydration unit 2 includes a first reservoir and a second reservoir respectively in fluid communication with the battery 1 , wherein the first reservoir stores a weak solvent-based electrolyte and the second reservoir stores a strong solvent compensation solution.

[0046] The monitoring unit 3 is used to monitor the operating condition of the battery 1 in real time and generate corresponding operating condition information.

[0047] The main control unit 4 is respectively connected to the rehydration unit 2 and the monitoring unit 3 for communication, and is used to obtain operating condition information from the monitoring unit 3, and control the rehydration unit 2 to input a weak solvent-based electrolyte or a strong solvent compensation solution into the battery 1 according to the operating condition information to rehydrate the battery 1.

[0048] In this embodiment, the battery 1 is preferably a sodium ion battery; the main control unit 4 is preferably composed of an embedded processor and its accessories.

[0049] A weak solvent-based electrolyte refers to an electrolyte with low solvating capacity. In this embodiment, the weak solvent-based electrolyte preferably has low viscosity, its solute is preferably 1.5 mol NaPF6, and its solvent is preferably ethylene carbonate (EC) and diethyl carbonate (DEC), with an EC:DEC ratio of 3:7.

[0050] A strong solvent compensating solution is an electrolyte with strong solvating capacity, primarily used in battery systems. In this embodiment, the solute of the strong solvent compensating solution is preferably 0.5 mol NaFSI, and the solvent is preferably 1% of the capacity compensating agent fluoroethylene carbonate (FEC).

[0051] In this embodiment, microcapsules containing FEC can be set inside the second liquid reservoir. The shell material of the microcapsule is preferably polyacrylate. When the FEC concentration of the strong solvent compensation liquid in the second liquid reservoir is lower than 0.8%, the microcapsules can automatically trigger the release of FEC.

[0052] In this embodiment, an ion selective membrane can also be set inside the first liquid reservoir and the second liquid reservoir. The ion selective membrane is preferably a Nafion membrane. The ion selective membrane can dynamically adjust the concentration of NaPF6 in the first liquid reservoir and the concentration of NaFSI in the second liquid reservoir.

[0053] The above technical solution monitors the battery's operating condition in real time and automatically replenishes the battery with either a weak-solvent electrolyte or a strong-solvent compensation solution based on this information, eliminating the need for manual intervention. Automatic battery replenishment reduces the battery's voltage differential, extending its cycle life while also preventing overcharge and over-discharge caused by increased voltage differentials within the battery pack.

[0054] Optionally, the operating condition of the battery 1 may include at least one of the electrolyte concentration, voltage, temperature, and SOC of the battery 1 .

[0055] The monitoring unit 3 may include an electrolyte monitoring unit and a battery management system. The electrolyte monitoring unit is used to monitor the electrolyte concentration of the battery 1, and the battery management system is used to monitor at least one of the voltage, temperature and SOC of the battery 1.

[0056] The electrolyte monitoring unit may include an electrolyte ion concentration sensor provided on each battery cell. Each electrolyte ion concentration sensor is communicatively connected to the main control unit 4. The electrolyte ion concentration sensor is preferably an impedance spectroscopy-based electrolyte ion concentration sensor, which utilizes electrochemical impedance spectroscopy (EIS) technology to detect ion concentration in the electrolyte.

[0057] The ion concentration of a battery's electrolyte directly affects its charge and discharge performance, energy density, and cycle life. Electrolyte ion concentration sensors can monitor changes in electrolyte ion concentration in real time, thereby assessing the battery's health. For example, abnormal fluctuations in electrolyte ion concentration during battery use may indicate issues such as electrolyte leakage or electrode material aging. Promptly identifying these issues can help prevent battery failure by taking proactive measures.

[0058] The battery management system communicates with the main control unit 4 and battery 1. The battery management system is an electronic system used to manage battery packs and plays a crucial role in battery applications. It monitors battery voltage in real time to ensure balanced voltage across the battery pack. If a battery voltage is abnormal, the management system will promptly issue an alarm, prompting the user to address the issue. Voltage monitoring can also promptly detect battery aging or damage. Batteries generate heat during the charging and discharging process. Excessive battery temperature can affect battery performance and lifespan, and even cause safety issues. The battery management system monitors battery temperature in real time using a temperature sensor. When the battery temperature exceeds a safe range, the management system takes measures such as cooling or halting charging and discharging. A battery's state of charge (SOC) reflects the remaining charge. The management system monitors the SOC and uses various methods to accurately estimate it, ensuring safe battery use and optimizing performance.

[0059] Optionally, the rehydration unit 2 may further include a microfluidic pump assembly, which is in fluid communication with the battery 1 , the first reservoir and the second reservoir, and is used to input a weak solvent-based electrolyte or a strong solvent compensation solution into the battery under the control of the main control unit 4 .

[0060] A microfluidic pump assembly is a device that can accurately deliver small amounts of fluid, enabling high-precision flow delivery. It typically consists of multiple microfluidic pumps and their control systems. In this embodiment, the microfluidic pump assembly preferably uses a piezoelectric ceramic pump, with a flow accuracy of preferably ±0.1 μL / s.

[0061] Each battery cell can be provided with an injection port, typically located at the top center or side of the battery housing, for injecting electrolyte into the battery 1. In this embodiment, the microfluidic pump assembly is preferably connected to the injection port of the battery 1 via a silicone microtubule, and precisely delivers a weak solvent-based electrolyte or a strong solvent compensation solution in a pulsed mode. Each battery cell is equipped with an independent silicone microtubule, and the pulsed mode preferably circulates the electrolyte by first opening it for 5ms and then closing it for 10ms.

[0062] Optionally, there may be multiple batteries 1. The operating condition of the battery 1 may further include a maximum voltage difference of the multiple batteries, where the maximum voltage difference is the maximum value of the difference between the voltage of each battery in the multiple batteries and the average voltage of the multiple batteries.

[0063] The main control unit 4 may be configured to determine a battery to be replenished among the multiple batteries according to the maximum pressure difference.

[0064] In this embodiment, the main control unit 4 preferably determines the battery to be refilled by the following method:

[0065] When the maximum voltage difference among the multiple batteries is greater than a preset voltage difference threshold, it is determined that the single battery corresponding to the maximum voltage difference needs to be replenished. The voltage difference threshold is preferably 30mV.

[0066] In this embodiment, the number of batteries 1 is five, the difference between the voltage of battery 1 and the average voltage of battery 1 is 50mV, the difference between the voltage of battery 2 and the average voltage of battery 1 is 20mV, and the difference between the voltage of batteries 3, 4, and 5 and the average voltage of battery 1 is 0mV. Therefore, the maximum voltage difference of battery 1 is 50mV.

[0067] The maximum voltage difference of battery 1 is greater than the voltage difference threshold of 30mV. The main control unit 4 determines that the maximum voltage difference is polarization-dominated and requires electrolyte intervention. The single cell corresponding to this maximum voltage difference is battery 1. Therefore, the main control unit 4 determines that battery 1 is the battery to be recharged.

[0068] Alternatively, the SOC of the battery 1 may include an average SOC of the plurality of batteries and a single cell SOC of each battery in the plurality of batteries.

[0069] The main control unit 4 may also be configured to: determine that a weak solvent-based electrolyte needs to be added to the battery to be replenished when the single SOC of the battery to be replenished is greater than the average SOC of the multiple batteries; and determine that a strong solvent compensation solution needs to be added to the battery to be replenished when the single SOC of the battery to be replenished is less than the average SOC of the multiple batteries.

[0070] Among them, adding a weak solvent-based electrolyte to the battery to be replenished can inhibit excessive desodiumization of the positive electrode material inside the battery to be replenished, thereby preventing the structural collapse of the positive electrode material inside the battery to be replenished.

[0071] Supplementing a strong solvent compensation solution to the battery to be replenished can reduce the deintercalation activation energy of the battery to be replenished and increase the ion migration rate inside the battery to be replenished.

[0072] Optionally, the operating condition of the battery 1 may further include a maximum temperature difference among the multiple batteries, where the maximum temperature difference is the temperature difference between the battery with the highest temperature and the battery with the lowest temperature among the multiple batteries.

[0073] The main control unit 4 can also be used to calculate the amount of fluid to be replenished for the battery to be replenished according to the following replenishment formula:

[0074] Q=k1·ΔV·e(-Ea / (R·Tavg))+k2·ΔT;

[0075] Among them, Q is the amount of fluid replacement, ΔV is the maximum pressure difference, ΔT is the maximum temperature difference, E a is the preset activation energy of the electrolyte, R is the preset ideal gas constant, Tavg is the preset ideal average temperature of multiple batteries, k1 is the preset pressure difference weight coefficient, and k2 is the preset temperature difference weight coefficient.

[0076] In this embodiment, k1 is specifically the weight coefficient of the pressure difference between the voltage of the battery to be replenished and the average voltage of multiple batteries on the replenishment amount, and k1 reflects the dominant influence of electrolyte polarization on the pressure difference; k2 is specifically the weight coefficient of the maximum temperature difference of multiple batteries on the replenishment amount, and k2 reflects the change in sodium ion migration efficiency caused by temperature unevenness.

[0077] In this embodiment, E a Preferably, it is 9000 J / mol, R is preferably 8.314 J / (mol·K), Tavg is preferably 25°C, i.e., 298K, k1 is preferably 0.032, and k2 is preferably 1.4.

[0078] In this embodiment, ΔV is 50mV, ΔT is 5°C, and the calculation process of Q is as follows:

[0079] Q=0.032·50·e(-9000 / (8.314·298))+1.4·5=7μL.

[0080] Optionally, the main control unit 4 may also be configured to determine a rehydration effect after rehydrating the battery to be rehydrated, and adjust the pressure difference weight coefficient and / or the temperature difference weight coefficient in the rehydration formula according to the rehydration effect.

[0081] The rehydration effect may include at least one of a voltage regulation effect, a temperature regulation effect, and an electrolyte ion concentration compensation effect.

[0082] The voltage regulation effect is the ratio of the pressure difference change after refilling of the battery to be refilled to the pressure difference before refilling, wherein the pressure difference change after refilling is the change in the pressure difference between the voltage of the battery to be refilled after this refilling and the average voltage of multiple batteries, and the pressure difference before refilling is the pressure difference between the voltage of the battery to be refilled before this refilling and the average voltage of multiple batteries.

[0083] The temperature regulation effect is the ratio of the change in the maximum temperature difference of the multiple batteries after the current fluid replenishment to the maximum temperature difference of the multiple batteries before the current fluid replenishment.

[0084] The electrolyte ion concentration compensation effect is the ratio of the change in the electrolyte ion concentration of the battery to be replenished after the current replenishment to the electrolyte ion concentration of the battery to be replenished before the current replenishment.

[0085] In this embodiment, the battery to be replenished is battery No. 1. Before this replenishment, the voltage difference between the voltage of battery No. 1 and the average voltage of battery 1 is 50mV; after this replenishment, the voltage difference between the voltage of battery No. 1 and the average voltage of battery 1 is 25mV; the change in the pressure difference of battery No. 1 after replenishment is the calculation result of 50mV minus 25mV, that is, 25mV; the pressure difference of battery No. 1 before replenishment is 50mV; the voltage regulation effect is the ratio of 25mV to 50mV, that is, 50%.

[0086] Before the rehydration, the maximum temperature difference of battery 1 was 5°C. After the rehydration, the maximum temperature difference of battery 1 was 2°C. The change in the maximum temperature difference of battery 1 after the rehydration is calculated by subtracting 2°C from 5°C, which is 3°C. The temperature regulation effect is the ratio of 3°C to 5°C, which is 60%.

[0087] Before this rehydration, the electrolyte ion concentration of battery No. 1 was 0.5 mol / L; after this rehydration, the electrolyte ion concentration of battery No. 1 was 0.2 mol / L; the change in electrolyte ion concentration of battery No. 1 after this rehydration was calculated by subtracting 0.2 mol / L from 0.5 mol / L, which is 0.3 mol / L; the electrolyte ion concentration compensation effect is the ratio of 0.3 mol / L to 0.5 mol / L, which is 60%.

[0088] The time interval before and after the current fluid infusion is preferably 30 seconds.

[0089] Optionally, the main control unit 4 may be specifically configured to adjust the pressure difference weight coefficient and / or the temperature difference weight coefficient in the fluid replenishment formula according to the following formula:

[0090] K1'=(1-Y1) / [(1-Y1)+(1-Y2)]·X·K1;

[0091] K2'=(X-K1')·K2;

[0092] Where Y1 is the voltage regulation effect, Y2 is the temperature regulation effect, and X is the electrolyte ion concentration compensation effect. K1 is the pressure difference weight coefficient before adjustment, K2 is the temperature difference weight coefficient before adjustment, K1' is the pressure difference weight coefficient after adjustment, and K2' is the temperature difference weight coefficient after adjustment.

[0093] In this embodiment, Y1 is 50%, Y2 is 60%, and X is 60%. The calculation processes of K1' and K2' are:

[0094] K1'=(1-50%) / [(1-50%)+(1-60%)]·60%·K1=33.33%K1;

[0095] K2'=(60%-33.33%)·K2=26.67%K2.

[0096] The principle of this operation is that the pressure difference weight coefficient and / or temperature difference weight coefficient in the rehydration formula can be adjusted according to the effect of this rehydration, so as to improve the accuracy of the pressure difference weight coefficient and / or temperature difference weight coefficient; the adjusted pressure difference weight coefficient and / or temperature difference weight coefficient is used for subsequent rehydration operations, which can improve the rehydration effect and thereby more effectively reduce the pressure difference of the battery.

[0097] Optionally, the power supply device may further include a recovery unit, which is connected to the multiple batteries and the microfluidic pump assembly respectively, and can be used to receive and decompose undecomposed electrolyte in the battery to be replenished after replenishment.

[0098] In this embodiment, the microfluidic pump assembly can be integrated with an electrochemical decomposition device; a liquid outlet can be set at the bottom of each battery, and each liquid outlet can be integrated with a porous ceramic membrane, and the pore size of the porous ceramic membrane is preferably less than or equal to 0.1 μm; the recovery unit can include a porous ceramic membrane and an electrochemical decomposition device.

[0099] After a weak solvent-based electrolyte or strong solvent compensation solution is introduced into the battery to be recharged, the internal liquid pressure of the battery increases, and undecomposed electrolyte flows out of the outlet. The porous ceramic membrane is used to collect the undecomposed electrolyte from the battery to be recharged through capillary action after recharge. After nanofiltration, it is then fed into the electrochemical decomposition device through a return hose.

[0100] The electrochemical decomposition device is used for decomposing sodium ions from undecomposed electrolyte and replenishing the sodium ions into the first liquid reservoir and the second liquid reservoir through the liquid return hose.

[0101] Based on the same inventive concept as the above embodiments, Figure 2 and Figure 3 The above embodiment is described in detail through a specific application scenario:

[0102] The power supply device includes five batteries, a microfluidic pump assembly, a first liquid reservoir, a second liquid reservoir, a main control unit, and a BMS. The microfluidic pump assembly is integrated with an electrochemical decomposition device.

[0103] Five cells form a battery pack, each equipped with an inlet and outlet. The outlet incorporates a porous ceramic membrane. The cell's inlet is fluidically connected to the microfluidic pump assembly via a silicone microtube. The cell's outlet is fluidically connected to the microfluidic pump assembly via a return hose. The microfluidic pump assembly is fluidically connected to the first and second reservoirs via the return hose.

[0104] An electrolyte ion concentration sensor is provided on each battery, and the electrolyte ion concentration sensor is connected to the main control unit via an ion concentration detection harness.

[0105] The microfluidic pump assembly is fluidically connected to the first and second liquid reservoirs through a fluid infusion hose; the main control unit is connected to the microfluidic pump assembly through a control harness; the BMS is connected to the main control unit through a communication harness, and is connected to the battery through a battery operating condition collection harness.

[0106] The power supply unit works as follows:

[0107] The BMS monitors the operating condition of the battery pack in real time and generates operating condition information, and the electrolyte ion concentration sensor monitors the electrolyte concentration of the battery pack in real time.

[0108] The main control unit obtains the operating condition information of the battery pack in real time from the BMS and electrolyte ion concentration sensor, including the voltage, temperature, maximum pressure difference and maximum temperature difference of the battery pack, the average SOC of the battery pack and the single cell SOC of each battery in the battery pack, as well as the electrolyte concentration of the battery pack.

[0109] When the maximum voltage difference of the battery pack is greater than 30mV, the main control unit determines that the single cell corresponding to the maximum voltage difference is a D-type battery, and determines that the D-type battery needs to be replenished.

[0110] At this time, the single SOC of battery No. 1 is greater than the average SOC of the battery pack, and the main control unit determines that a weak solvent-based electrolyte needs to be added to battery No. 1.

[0111] The main control unit calculates the refill volume of the No. 1 battery according to the maximum temperature difference and maximum pressure difference of the battery pack and the preset refill formula.

[0112] The main control unit controls the first liquid reservoir and the microfluidic pump assembly to input a weak solvent-based electrolyte into the No. 1 battery.

[0113] After refilling the No. 1 battery, the main control unit determines the refilling effect according to the working condition information of the battery pack, and adjusts the pressure difference weight coefficient and / or temperature difference weight coefficient in the refilling formula according to the refilling effect.

[0114] The porous ceramic membrane receives the undecomposed electrolyte in the No. 1 battery after rehydration, and after nanofiltration, it is input into the electrochemical decomposition device through the return hose.

[0115] The electrochemical decomposition device decomposes sodium ions from the undecomposed electrolyte and replenishes the sodium ions to the first liquid reservoir and the second liquid reservoir through the liquid return hose.

[0116] Another embodiment of the present application provides an energy storage system, including the power supply device as described above.

[0117] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to cover a non-exclusive inclusion of elements other than the listed elements and may also include additional elements not specifically listed.

[0119] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A power supply device, characterized in that: include: Battery; a fluid replenishing unit, the fluid replenishing unit comprising a first reservoir and a second reservoir respectively in fluid communication with the battery, the first reservoir storing a weak solvent-based electrolyte, and the second reservoir storing a strong solvent compensation solution; A monitoring unit, configured to monitor the operating condition of the battery in real time and generate corresponding operating condition information; a main control unit, the main control unit being communicatively connected to the rehydration unit and the monitoring unit, respectively, and configured to obtain the operating condition information from the monitoring unit, and control the rehydration unit to input the weak solvent-based electrolyte or the strong solvent compensation solution into the battery according to the operating condition information, so as to rehydrate the battery; The main control unit is further configured to calculate the amount of fluid to be replenished for the battery to be replenished according to the following replenishment formula: Q=k1·ΔV·e(-Ea / (R·Tavg))+k2·ΔT; Wherein, Q is the amount of fluid replacement, ΔV is the maximum pressure difference, ΔT is the maximum temperature difference, E a is the preset activation energy of the electrolyte, R is the preset ideal gas constant, Tavg is the preset ideal average temperature of multiple batteries, k1 is the preset pressure difference weight coefficient, k2 is the preset temperature difference weight coefficient; e is a natural constant; The main control unit is further configured to determine a rehydration effect after rehydrating the battery to be rehydrated, and adjust the pressure difference weight coefficient and / or the temperature difference weight coefficient in the rehydration formula according to the rehydration effect; The main control unit is specifically configured to adjust the pressure difference weight coefficient and / or the temperature difference weight coefficient in the fluid replenishment formula according to the following formula: K1'=(1-Y1) / [(1-Y1)+(1-Y2)]·X·K1; K2'=(X-K1')·K2; Among them, Y1 is the voltage regulation effect, Y2 is the temperature regulation effect, X is the electrolyte ion concentration compensation effect; K1 is the pressure difference weight coefficient before adjustment, K2 is the temperature difference weight coefficient before adjustment, K1' is the pressure difference weight coefficient after adjustment, and K2' is the temperature difference weight coefficient after adjustment.

2. The power supply device according to claim 1, wherein: The operating condition of the battery includes at least one of the electrolyte concentration, voltage, temperature, and SOC of the battery; The monitoring unit includes an electrolyte monitoring unit and a battery management system (BMS); the electrolyte monitoring unit is used to monitor the electrolyte concentration of the battery, and the BMS is used to monitor at least one of the voltage, temperature and SOC of the battery.

3. The power supply device according to claim 2, wherein: The rehydration unit further includes a microfluidic pump assembly, which is fluidically connected to the battery, the first reservoir, and the second reservoir, and is used to input the weak solvent-based electrolyte or the strong solvent compensation solution into the battery under the control of the main control unit.

4. The power supply device according to claim 3, wherein: There are multiple batteries; the operating condition of the battery further includes a maximum voltage difference of the multiple batteries, where the maximum voltage difference is the maximum value of the difference between the voltage of each battery in the multiple batteries and the average voltage of the multiple batteries; The main control unit is configured to determine a battery to be replenished among the multiple batteries according to the maximum pressure difference.

5. The power supply device according to claim 4, wherein: The SOC of the battery includes an average SOC of the plurality of batteries and a single cell SOC of each battery in the plurality of batteries; The main control unit is further configured to: determine that the weak solvent-based electrolyte needs to be replenished to the battery to be replenished when the single SOC of the battery to be replenished is greater than the average SOC of the plurality of batteries; When the single cell SOC of the battery to be replenished is less than the average SOC of the plurality of batteries, it is determined that the battery to be replenished needs to be replenished with the strong solvent compensation solution.

6. The power supply device according to claim 4, wherein: The operating condition of the battery further includes a maximum temperature difference of the multiple batteries, where the maximum temperature difference is a temperature difference between a battery with the highest temperature and a battery with the lowest temperature among the multiple batteries.

7. The power supply device according to claim 6, wherein: The rehydration effect includes at least one of a voltage regulation effect, a temperature regulation effect, and an electrolyte ion concentration compensation effect; The voltage regulation effect is a ratio of a change in the pressure difference of the battery to be replenished after replenishment to a change in the pressure difference before replenishment, wherein the change in the pressure difference after replenishment is a change in the pressure difference between the voltage of the battery to be replenished after this replenishment and an average voltage of the multiple batteries, and the pressure difference before replenishment is a pressure difference between the voltage of the battery to be replenished before this replenishment and the average voltage of the multiple batteries; The temperature regulation effect is the ratio of the change in the maximum temperature difference of the multiple batteries after the current fluid replenishment to the maximum temperature difference of the multiple batteries before the current fluid replenishment; The electrolyte ion concentration compensation effect is the ratio of the change in the electrolyte ion concentration of the battery to be replenished after the current replenishment to the electrolyte ion concentration of the battery to be replenished before the current replenishment.

8. The power supply device according to claim 4, wherein: The power supply device further includes a recovery unit, which is connected to the multiple batteries and the microfluidic pump assembly respectively, and is used to receive and decompose undecomposed electrolyte in the batteries to be replenished after replenishment.

9. An energy storage system, characterized in that: The device comprises a power supply as claimed in any one of claims 1 to 8.

Images