A method and system for recovering liquid metal batteries under micro-short circuit conditions

Abstract

A method for recovering a liquid metal battery in a micro-short circuit includes: when the liquid metal battery is in a micro-short circuit; heating the liquid metal battery and charging it, and judging whether the liquid metal battery has recovered during the charging process; if it has not recovered after a preset first time period, cooling the battery to room temperature and then heating it again and charging it until the liquid metal battery returns to normal. The technical solution provided by the present invention can recover a liquid metal battery in a micro-short circuit.

Description

Technical Field

[0001] The present invention relates to the field of energy storage batteries, and in particular to a method and system for recovering a liquid metal battery under micro-short circuit conditions. Background Art

[0002] As the world faces the problem of fossil energy depletion, countries are actively developing new renewable energy sources that can replace fossil energy. However, most renewable energy sources such as wind power and solar energy face the disadvantages of intermittency and volatility, which will lead to a decline in the quality of power supply of the power grid, and then bring about the problem of difficulty in grid connection. At the same time, with the advent of the smart grid era, the traditional power system cannot well meet the increasing power demand of users, such as insufficient power supply during peak hours and oversupply during off-peak hours.

[0003] In response to these problems, large-scale energy storage technology has emerged. By storing electricity during periods of sufficient wind and solar energy and releasing it during periods of energy shortage, energy storage technology can "cut peaks and fill valleys" and smooth the output of new energy power generation technology. At the same time, it stores electricity during low-peak periods of power consumption in the power grid and releases it during peak periods of power consumption in the power grid, so as to "cut peaks and fill valleys" for the power grid and achieve stable output of the power grid. Large-scale energy storage technology is mainly divided into pumped energy storage, compressed air energy storage, flywheel energy storage, supercapacitor energy storage and battery energy storage. Among them, battery energy storage technology has been widely valued by people due to its advantages such as high energy conversion efficiency, flexible configuration and design, and no restrictions on environmental conditions. At present, the battery technologies used in the field of energy storage include modified lead-acid battery technology, lithium-ion battery technology, sodium-sulfur battery technology and all-vanadium liquid flow battery technology. However, facing the actual demand of the energy storage market, the existing battery technology still has problems such as short life and high cost.

[0004] In order to meet the energy storage market's requirements for energy storage batteries, MIT professor D.R. Sadoway proposed the concept of "liquid metal battery" in 2007. The all-liquid metal battery model uses liquid metal as the positive and negative electrodes and liquid molten salt as the electrolyte. The mutual immiscibility and density differences make the liquid metal negative electrode, liquid molten salt and liquid metal positive electrode naturally divided into three layers from top to bottom. This battery structure makes the battery assembly easier and reduces the manufacturing cost. At the same time, the liquid metal positive and negative electrodes will also avoid failure problems caused by stress fatigue and short circuit problems caused by branched growth, so the cycle life of the battery can be greatly improved. At the same time, the high conductivity of the liquid molten salt electrolyte allows the battery to be charged and discharged at high rates, meeting the high power requirements of large-scale energy storage technology.

[0005] However, liquid metal batteries are prone to short circuits in the first few cycles of operation, which is called micro short circuit. Micro short circuit is a phenomenon that greatly damages the performance of liquid metal batteries. There is no liquid metal battery recovery method for micro short circuit in the prior art. Summary of the invention

[0006] The present invention provides a method for recovering a liquid metal battery under a micro-short circuit condition, comprising:

[0007] When the liquid battery is in a micro short circuit;

[0008] The liquid metal battery is heated up and then charged, and during the charging process, it is determined whether the liquid metal battery is recovered;

[0009] If there is no recovery after the preset first period of time, the battery is cooled to room temperature and then heated up and charged again until the liquid metal battery returns to normal.

[0010] Preferably, the step of heating the liquid metal battery and then charging it comprises:

[0011] Heating up the liquid metal battery;

[0012] The liquid metal battery is charged using a constant voltage, and during the charging process, it is determined whether the liquid metal battery is restored according to the change of the battery current, and if it is restored, the charging state is exited;

[0013] Otherwise, continue to determine whether the liquid metal battery has recovered. When the preset second time period is reached, if the battery current has not recovered, the liquid metal is charged with a pulse constant voltage.

[0014] Preferably, the charging of the liquid metal by using a pulse constant voltage comprises:

[0015] S1 charges the liquid metal battery using a pulse constant voltage for a third time period, and determines whether the liquid metal battery is restored according to the change of the battery current during the charging process; if restored, exits the charging state;

[0016] S2: Otherwise, stop charging, and execute step S1 again after a fourth interval, until the preset interval is reached.

[0017] Preferably, the determining whether the liquid metal battery is restored includes:

[0018] Check whether the battery current is less than the current setting threshold.

[0019] Preferably, the constant voltage and the pulse constant voltage are both 2 volts.

[0020] Preferably, the current setting threshold is 1 ampere.

[0021] Preferably, the preset second duration is any time length between 3 and 10 hours;

[0022] The third duration can be any time length between 3 and 10 hours;

[0023] The fourth duration may be any length of time between 1 and 3 hours.

[0024] Preferably, the preset first duration is greater than the sum of the preset second duration, the third duration and the fourth duration.

[0025] A system for recovering a liquid metal battery in a micro-short circuit situation, comprising: a temperature rise charging module and a judgment module;

[0026] The heating charging module is used to heat the liquid metal battery and charge it when the liquid battery is in a micro-short circuit, and to heat and charge it again when the liquid metal battery has not recovered after charging for a preset time;

[0027] The judgment module is used to judge whether the liquid metal battery is restored during the charging process, and whether the liquid metal battery is restored after charging reaches a preset time.

[0028] Preferably, the temperature rising charging module comprises:

[0029] A heating unit, used for heating the liquid metal battery;

[0030] A constant voltage charging unit, used to charge the liquid metal battery using a constant voltage;

[0031] A pulse constant voltage charging unit is used to perform pulse constant voltage charging on the liquid metal when the liquid metal battery has not recovered after the charging time of the constant voltage charging unit reaches a preset time.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides a method for recovering a liquid metal battery under micro-short circuit conditions, comprising: when the liquid battery is in a micro-short circuit; heating the liquid metal battery and then charging it, and determining whether the liquid metal battery has recovered during the charging process; if it has not recovered after a preset period of time, cooling the battery to room temperature and then heating it again and charging it until the liquid metal battery returns to normal. The technical solution provided by the present invention effectively solves the problem of micro-short circuits of liquid metal batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of a method for recovering a liquid metal battery according to the present invention;

[0035] Figure 2This is a schematic diagram of the algorithm of the liquid metal battery recovery method of the present invention. DETAILED DESCRIPTION

[0036] The present invention discloses a method for recovering a liquid metal battery in the case of a micro-short circuit. The device has a good recovery effect on the micro-short circuit that occasionally occurs during the initial operation of the liquid metal battery, and can make full use of the liquid metal battery's own good self-repairing property. It is a conventional and effective liquid metal battery repair operation method:

[0037] Example 1: A method for recovering a liquid metal battery under micro-short circuit conditions, such as Figure 1 As shown, the following steps are included:

[0038] When the liquid battery is in a micro short circuit;

[0039] The liquid metal battery is heated up and then charged, and during the charging process, it is determined whether the liquid metal battery is recovered;

[0040] If there is no recovery after the preset first period of time, the battery is cooled to room temperature and then heated up and charged again until the liquid metal battery returns to normal.

[0041] Specific as Figure 2 As shown:

[0042] S1. Raise the temperature of the slightly short-circuited liquid metal battery, use constant voltage to continuously charge for a preset second time period, and detect the change in self-discharge current to determine whether the liquid metal battery has recovered; if the current gradually decreases to below the current setting threshold as the constant voltage time increases, it proves that it has recovered and exits;

[0043] S2. If the current remains above the current setting threshold after the preset second time period, it proves that it has not recovered and needs to continue intermittent charging using pulse constant voltage;

[0044] S3. If the pulse constant voltage of the slightly short-circuited liquid metal battery still cannot make the self-discharge current greater than the current setting threshold, the battery is cooled to room temperature, and then heated to the operating temperature again, and steps S1 and S2 are repeated.

[0045] Among them, the current setting threshold is 500mA.

[0046] The constant voltage used is 2 volts.

[0047] The current setting threshold is 1 ampere.

[0048] The pulse constant voltage is 2 volts.

[0049] The preset duration is between 3 and 10 hours.

[0050] The interval duration is 1 hour.

[0051] Embodiment 2:

[0052] S1. Heat up the slightly short-circuited liquid metal battery, charge it with a constant voltage, and keep it for a certain period of time. During the test, detect the self-discharge current so that the self-discharge current is less than 1 ampere.

[0053] S2. If the above S1 process cannot restore the battery to normal charge and discharge state, a pulse constant voltage charging method is used. After a certain period of constant voltage charging, a certain period of rest is performed. During the test, the self-discharge current is detected to make the self-discharge current less than 1 ampere. Repeat this step until the battery returns to normal. If it cannot return to normal, go to S3.

[0054] S3: Cool the battery down to room temperature and then heat it up to operating temperature.

[0055] S4. Repeat steps S1, S2, and S3 until the battery returns to normal.

[0056] Furthermore, the constant voltage charging voltage in S1 can be selected to be around 2 volts.

[0057] Furthermore, the pulse constant voltage charging voltage in S2 can be selected to be around 2 volts.

[0058] Furthermore, the pulse frequency of the pulse constant voltage charging in S2 is

[0059] Furthermore, the constant voltage charging time in S1 is 3 to 10 hours.

[0060] Furthermore, the constant voltage charging time in S2 is maintained at 3 to 10 hours, and the intermittent time is 1 hour.

[0061] The method of the present invention has a good recovery effect on the micro-short circuit that occasionally occurs during the initial operation of the liquid metal battery, and can fully utilize the liquid metal battery's own excellent self-repairing properties. It is a conventional and effective liquid metal battery repair operation method.

[0062] Embodiment 3:

[0063] Based on the same inventive concept, the present invention also provides a system for recovering a liquid metal battery under a micro-short circuit, comprising:

[0064] Heating charging module and judgment module;

[0065] The heating charging module is used to heat the liquid metal battery and charge it when the liquid battery is in a micro-short circuit, and to heat and charge it again when the liquid metal battery has not recovered after charging for a preset first time period;

[0066] The judgment module is used to judge whether the liquid metal battery is restored during the charging process, and whether the liquid metal battery is restored after charging reaches a preset first time length.

[0067] The temperature rising charging module comprises:

[0068] A heating unit, used for heating the liquid metal battery;

[0069] A constant voltage charging unit, used to charge the liquid metal battery using a constant voltage;

[0070] A pulse constant voltage charging unit is used to perform pulse constant voltage charging on the liquid metal when the liquid metal battery has not recovered after the charging time of the constant voltage charging unit reaches a preset second time.

[0071] The pulse constant voltage charging unit includes: a pulse charging subunit and a pulse judging subunit.

[0072] The pulse charging subunit is used to charge the liquid metal battery using a pulse constant voltage for a third time period;

[0073] The pulse judgment subunit is used to judge whether the liquid metal battery has recovered according to the change of battery current during the charging process. If it has recovered, the charging state is exited. Otherwise, it is judged whether the preset time has been reached. If the preset time has been reached, the charging is exited. Otherwise, after the fourth interval, charging is performed again through the pulse charging subunit until the preset time is reached or / and the metal battery is recovered.

[0074] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0075] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0076] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0077] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0078] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A method for recovering a liquid metal battery under micro-short circuit conditions, characterized in that: include: When the liquid battery is in a micro short circuit; The liquid metal battery is heated up and then charged, and during the charging process, it is determined whether the liquid metal battery is recovered; If the battery is not restored after the preset first time period, the battery is cooled to room temperature and then heated up and charged again until the liquid metal battery returns to normal; The step of heating the liquid metal battery and then charging it comprises: Heating up the liquid metal battery; The liquid metal battery is charged using a constant voltage, and during the charging process, it is determined whether the liquid metal battery is restored according to the change of the battery current, and if it is restored, the charging state is exited; Otherwise, continue to determine whether the liquid metal battery is restored, and when the preset second time period is reached, if the battery current has not been restored, charge the liquid metal with a pulse constant voltage; The method of charging the liquid metal by using a pulse constant voltage comprises: S1 charges the liquid metal battery using a pulse constant voltage for a third time period, and determines whether the liquid metal battery is restored according to the change of the battery current during the charging process; if restored, exits the charging state; S2: Otherwise, stop charging, and perform step S1 again after a fourth interval, until the preset interval is reached; The determining whether the liquid metal battery is recovered includes: Detect whether the battery current is less than the current setting threshold; The preset first duration is greater than the sum of the preset second duration, the third duration and the fourth duration.

2. The method for recovering a liquid metal battery according to claim 1, characterized in that: The constant voltage and the pulse constant voltage are both 2 volts.

3. The method for recovering a liquid metal battery according to claim 1, characterized in that: The current setting threshold is 1 ampere.

4. The method for recovering a liquid metal battery according to claim 1, characterized in that: The preset second duration is any time length between 3 and 10 hours; The third duration can be any time length between 3 and 10 hours; The fourth duration may be any length of time between 1 and 3 hours.

5. A system for implementing the method for recovering a liquid metal battery under a micro-short circuit as claimed in any one of claims 1 to 4, characterized in that: include: Heating charging module and judgment module; The heating charging module is used to heat the liquid metal battery and charge it when the liquid battery is in a micro-short circuit, and to heat and charge it again when the liquid metal battery has not recovered after charging for a preset time; The judgment module is used to judge whether the liquid metal battery is restored during the charging process, and whether the liquid metal battery is restored after charging reaches a preset time.

6. The system according to claim 5, characterized in that The temperature rising charging module comprises: A heating unit, used for heating the liquid metal battery; A constant voltage charging unit, used to charge the liquid metal battery using a constant voltage; A pulse constant voltage charging unit is used to perform pulse constant voltage charging on the liquid metal when the liquid metal battery has not recovered after the charging time of the constant voltage charging unit reaches a preset time.

Images