Liquid metal battery with metal separator

Abstract

The utility model provides a liquid metal battery with a metal partition plate. The liquid metal battery comprises a battery shell, an electrode stem and electrolyte, a mounting hole is formed in the top of the battery shell; a negative current collector wraps the outer wall of the lower end of the electrode stem; a metal partition plate is fixedly arranged on the inner wall of the battery shell, a positive electrode material is fixed on the metal partition plate, and the electrolyte is filled in the battery shell. The liquid metal battery disclosed by the utility model has the beneficial effects that the positive electrode materials of the liquid metal battery are solidified and fixed on the metal partition plates, and the metal partition plates are uniformly fixed on the inner wall of the battery shell, so that certain distances are formed between the positive electrode materials on different metal partition plates and between the positive electrode materials and negative electrode materials; therefore, arching of large-area intermetallic compounds due to stress accumulation in the charging and discharging process is avoided, short circuit of the positive electrode material and the negative electrode is avoided, and the service life is prolonged. And the liquid metal battery with the metal partition plate is convenient for realizing multi-layer electrode stacking in the same closed battery shell, and is beneficial to improving the stability of a high-capacity battery.

Description

Technical Field

[0001] This utility model relates to the field of energy storage batteries, and in particular to a liquid metal battery with a metal separator. Background Technology

[0002] Currently, large-capacity energy storage technologies are mainly divided into three categories: chemical energy storage (such as lithium-ion batteries, sodium-sulfur batteries, and flow batteries), physical energy storage (such as pumped hydro storage, compressed air storage, and flywheel energy storage), and electromagnetic energy storage (such as superconducting magnetic energy storage and supercapacitors). Chemical energy storage has attracted widespread attention due to its advantages such as pollution-free operation, high conversion efficiency, and low maintenance. However, in large-scale grid energy storage applications, these batteries suffer from problems such as high cost and poor safety. For example, lithium-ion batteries have high production costs and limited lithium resources; vanadium redox flow batteries, made from vanadium, have high toxicity and limited resources. Therefore, the development of technologies with advantages such as low cost, long cycle life, good safety, and abundant raw materials for large-scale grid energy storage is urgently needed.

[0003] Liquid metal batteries are a new type of rechargeable battery designed for grid-scale energy storage applications. A single cell mainly consists of a positive electrode, a negative electrode, an electrolyte, and a battery casing. At operating temperatures of 200–700°C, both electrodes are liquid metals, and the electrolyte is a molten inorganic salt. Due to their different densities and immiscibility, the electrodes and electrolyte naturally separate into layers, with the electrolyte naturally separating the two electrodes. This specially designed battery offers advantages such as high coulombic efficiency, long cycle life, good safety performance, and low cost, making it suitable for grid-connected energy storage systems for wind power, solar power, and other energy generation applications.

[0004] However, in some electrode systems, the negative and positive electrode materials alloy during charging and discharging, forming solid intermetallic compounds at high temperatures. As the discharge process continues, the composition of these intermetallic compounds changes, generating internal stress that causes the intermetallic compound layer to arch, connecting the positive and negative electrodes and causing a short circuit in the battery. Furthermore, while this naturally layered electrode structure is easy to scale up for production, it requires high precision in the module's horizontal alignment and also limits the development of different battery configurations.

[0005] Therefore, the existing electrode configurations for liquid metal batteries need to be improved. Utility Model Content

[0006] In view of this, the present invention provides a liquid metal battery with a metal separator, comprising a battery casing, electrode rods and electrolyte;

[0007] The battery casing has a mounting hole at the top, and the lower end of the electrode rod extends into the battery casing through the mounting hole. The electrode rod is fixed in the mounting hole by an insulating component.

[0008] The portion of the electrode rod extending into the battery casing is connected to a negative electrode current collector.

[0009] Multiple metal partitions are fixed to the inner wall of the battery casing, and positive electrode material is fixed on the metal partitions;

[0010] The electrolyte is filled inside the battery casing, and the height of the upper surface of the electrolyte exceeds the height of all metal separators and the upper end height of the negative electrode current collector.

[0011] Furthermore, one end of the metal separator is welded to the inner wall of the battery casing, and the other end extends toward the axis of the battery casing, with the metal separator forming an angle of less than 90° with the inner wall of the battery casing.

[0012] Furthermore, the positive electrode material is one or more of Bi, Sb, Pb, Sn, In, Te, and Ga.

[0013] Furthermore, the metal partition is made of stainless steel or titanium alloy.

[0014] Furthermore, the negative electrode current collector includes a negative electrode current collector with a porous structure, and the negative electrode material is adsorbed within the porous structure of the negative electrode current collector.

[0015] Furthermore, the negative electrode material is one or more of Li, Na, K, Mg, and Ca.

[0016] Furthermore, the porosity of the negative current collector is 60%~99%, and the pore size is less than 1mm.

[0017] Furthermore, the electrolyte material is one or more of the halogenated inorganic salts corresponding to the negative electrode material.

[0018] Furthermore, all metal separators are symmetrically fixed to the inner wall of the battery casing in two groups, with all metal separators in the same group arranged in parallel.

[0019] Furthermore, the positive electrode material is solidified above the metal separator.

[0020] The beneficial effects of this liquid metal battery with metal separators are as follows: the positive electrode material of the liquid metal battery is solidified and fixed on the metal separators, which uniformly fix the inner wall of the battery casing. This ensures that the positive electrode material is firmly fixed to the battery casing. Furthermore, there are certain gaps between the positive electrode materials on different metal separators, and between the positive and negative electrode materials. This prevents the formation of large-area intermetallic compounds during charging and discharging, which can cause arching due to stress accumulation, thus avoiding short circuits between the positive and negative electrodes and extending the service life. Additionally, the vertical electrode arrangement of this liquid metal battery with metal separators means that performance is not affected even if the battery is tilted, and the requirements for battery levelness are lower. Moreover, this liquid metal battery with metal separators facilitates multi-layer electrode stacking within the same sealed battery casing, which is beneficial for improving the stability of large-capacity batteries. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of a liquid metal battery with a metal separator according to an embodiment of the present invention;

[0022] Figure 2 This is a charge-discharge curve of a liquid metal battery with a metal separator according to an embodiment of the present invention;

[0023] Figure 3 This is a cycle performance diagram of a liquid metal battery with a metal separator according to an embodiment of the present invention at different rates;

[0024] In the diagram: 1-battery casing, 2-metal separator, 3-positive electrode material, 4-electrode rod, 5-electrolyte, 6-negative electrode current collector, 7-insulator. Detailed Implementation

[0025] To make the objectives, technical solutions and advantages of this utility model clearer, the embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0026] Please refer to Figure 1 A liquid metal battery with a metal separator according to an embodiment of the present invention includes a battery casing 1, an electrode rod 4, and an electrolyte 5.

[0027] The battery housing 1 is a cylindrical structure. In this embodiment, the battery housing 1 is a square cylindrical structure, including an upper cover and a lower housing. The upper cover has a mounting hole at its center and is welded to the lower housing, thus making the battery housing 1 a square cylindrical structure with a mounting hole at the top. The lower end of the electrode rod 4 extends into the battery housing 1 through the mounting hole, and the upper end of the electrode rod 4 is also provided with a limiting cap. The electrode rod 4 is fixed in the mounting hole by an insulating component 7. In this embodiment, the insulating component 7 is a circular, sleeve-shaped, sealing insulating ceramic component. The insulating component 7 seals the mounting hole.

[0028] The portion of the electrode rod 4 extending into the battery casing 1 is fitted with a negative electrode current collector 6. In this embodiment, the negative electrode current collector 6 includes a negative electrode current collector with a porous structure. The negative electrode current collector is a metal mesh circular sleeve structure, and negative electrode material is adsorbed in the porous structure of the negative electrode current collector.

[0029] Multiple metal separators 2 are fixedly arranged on the inner wall of the battery casing 1. Positive electrode material 3 is fixed on each metal separator 2. In this embodiment, all metal separators 2 are symmetrically fixed to the inner wall of the battery casing in two groups, i.e., the two groups of metal separators 2 are located on both sides of the electrode rod 4. All metal separators 2 belonging to the same group are arranged parallel to each other and are positioned vertically relative to each other. The spacing between adjacent metal separators 2 within the same group is equal. The positive electrode material 3 is solidified above the metal separators 2.

[0030] The electrolyte 5 is filled inside the battery casing 1, and the height of the upper surface of the electrolyte 5 exceeds the height of the upper ends of all the positive electrode materials 3 and the upper end of the negative electrode current collector 6. The distance between the negative electrode current collector 6 and the bottom of the battery casing is 3~10mm, and the distance between it and the positive electrode material 3 is 3~15mm.

[0031] In the above structure, the positive electrode material 3 is solidified and fixed on the metal separator 2, which uniformly fixes the inner wall of the battery casing 1. This ensures that the positive electrode material 3 is firmly fixed to the battery casing 1. Furthermore, there are certain gaps between the positive electrode materials 3 on different metal separators 2, and between the positive electrode material 3 and the negative electrode material. This prevents the formation of large-area intermetallic compounds during charging and discharging, which can cause arching due to stress accumulation, thus preventing short circuits between the positive electrode material 3 and the negative electrode and extending the service life. Moreover, the vertical electrode arrangement of this liquid metal battery with metal separators means that performance is not affected even if the battery is tilted, and the requirements for battery levelness are lower. In addition, this liquid metal battery with metal separators facilitates multi-layer electrode stacking within the same sealed battery casing, which is beneficial for improving the stability of high-capacity batteries.

[0032] In a preferred embodiment, the positive electrode material 3 is one or more selected from Bi, Sb, Pb, Sn, In, Te, and Ga. The negative electrode material is one or more selected from Li, Na, K, Mg, and Ca.

[0033] The metal separator 2 is made of stainless steel or titanium alloy. The metal separator 2 is fixed to the inner wall of the battery casing 1 by welding. The porous structure of the negative electrode current collector 6 has a porosity of 60%~99% and a pore size of less than 1mm. The electrolyte 5 is a mixture of one or more of the halogen inorganic salts corresponding to the negative electrode material.

[0034] In a preferred embodiment, one end of the metal separator 2 is welded to the inner wall of the battery casing, and the other end extends toward the axis of the battery casing. The metal separator 2 forms an angle of less than 90° with the inner wall of the battery casing. This makes the metal separator 2 and the upper part of the inner wall of the battery casing form a support platform with an acute angle, which facilitates the solidification of the positive electrode material 3 on the metal separator 2 and prevents the positive electrode material 3 from falling off the metal separator 2, thereby improving the stability and durability of the battery structure.

[0035] refer to Figure 2 and Figure 3 , Figure 2 and Figure 3 The figures show the charge-discharge curves of the liquid metal battery with metal separators and its cycle performance at different rates, respectively. Figure 2 As can be seen, the structure of the liquid metal battery with the metal separator increases the reaction interface between the electrode and the electrolyte 5, resulting in faster reaction kinetics. Therefore, compared with traditional battery structures, the battery has less polarization and thus higher energy efficiency. Figure 3 It can be seen that the battery has high stability, and compared with traditional batteries, the energy efficiency of the liquid metal battery with metal separator is significantly improved under the same conditions.

[0036] The following is an assembly process of a liquid metal battery with a metal separator according to this application, wherein in this embodiment, the positive electrode material is Li, the negative electrode material is Bi, and the electrolyte is a mixed molten salt of LiCl-LiBr-KBr;

[0037] S1: Weld the metal separator 2 to the inner wall of the battery casing 1, and process the metal top cover of the battery casing 1; wherein the metal top cover has a through hole in the middle;

[0038] S2: Fix the negative current collector to the electrode rod 4, and then install the insulating part 7 on the through hole of the metal cover; use the insulating part 7 to tightly connect the top of the electrode rod 4 to the cover.

[0039] S3: Place the positive electrode material 3 on the metal separator 2 and heat it until the positive electrode material 3 melts; wait for the positive electrode material 3 to completely cool and solidify on the metal separator 2.

[0040] S4: The negative electrode material is heated to melt. Utilizing the good wettability between the negative electrode current collector and the negative electrode material, the liquid negative electrode material is absorbed. After complete cooling, the negative electrode current collector 6 is obtained. Next, the electrolyte 5 is placed in the battery cavity, and then the metal cover connected to the negative electrode current collector 6 is welded to the battery cavity to complete the battery manufacturing process.

[0041] These batteries underwent charge-discharge testing, with a charging upper limit voltage of 1.2V and a discharging lower limit voltage of 0.6V. The energy efficiency reached 90% at 0.1C and 65% at 0.5C. After 250 cycles at 0.1C, there was virtually no capacity decay, and the coulombic efficiency reached 99%.

[0042] In this document, the directional terms such as front, back, top, and bottom are defined based on the location of the components in the accompanying drawings and their relative positions to each other, solely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application.

[0043] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0044] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A liquid metal battery having a metal separator, characterized by: Includes battery casing, electrode rods, and electrolyte; The battery casing has a mounting hole at the top, and the lower end of the electrode rod extends into the battery casing through the mounting hole. The electrode rod is fixed in the mounting hole by an insulating component. The portion of the electrode rod extending into the battery casing is connected to a negative electrode current collector. Multiple metal partitions are fixed to the inner wall of the battery casing, and positive electrode material is fixed on the metal partitions; The electrolyte is filled inside the battery casing, and the height of the upper surface of the electrolyte exceeds the height of all metal separators and the upper end height of the negative electrode current collector.

2. The liquid metal battery with metal separators of claim 1, wherein: One end of the metal separator is welded to the inner wall of the battery casing, and the other end extends toward the axis of the battery casing, with the metal separator forming an angle of less than 90° with the inner wall of the battery casing.

3. The liquid metal battery having a metal separator of claim 2, wherein: The metal partition is made of stainless steel or titanium alloy.

4. The liquid metal battery with metal separators of claim 1, wherein: The negative electrode current collector includes a negative electrode current collector with a porous structure, and the negative electrode material is adsorbed in the porous structure of the negative electrode current collector.

5. The liquid metal battery having a metal separator of claim 4, wherein: The porosity of the negative current collector is 60%~99%, and the pore size is less than 1mm.

6. The liquid metal battery having a metal separator of claim 2, wherein: All metal separators are symmetrically fixed to the inner wall of the battery casing in two groups, and all metal separators in the same group are arranged in parallel.

7. The liquid metal battery having a metal separator of claim 6, wherein: The positive electrode material is solidified above the metal separator.

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