Novel liquid metal battery

Abstract

The utility model provides a novel liquid metal battery, which relates to the field of energy storage batteries and 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 positive current collector is fixedly arranged on the inner wall of the battery shell, and the electrolyte is filled in the battery shell. The novel liquid metal battery has the beneficial effects that the positive electrode current collector of the novel liquid metal battery is of the porous sleeve structure, and the positive electrode material is borne and bound in a small area of the porous structure, so that the arching of large-area intermetallic compounds due to stress accumulation in the charging and discharging process is avoided, the short circuit with the negative electrode is avoided, and the service life is prolonged; and the thickness of an electrolyte layer between positive and negative electrodes can be reduced. And the electrodes of the battery are vertically arranged, so that the performance is not influenced even if the battery is inclined, and the requirement on the levelness of the battery is low. In addition, according to the battery, multi-layer electrode stacking can be conveniently realized in the same closed battery shell, and the stability of the high-capacity battery is favorably improved.

Description

Technical Field

[0001] This utility model relates to the field of energy storage batteries, and in particular to a novel liquid metal battery. 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 novel liquid metal battery, comprising a battery casing, electrode rods, and an 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 outer wall of the portion of the electrode rod extending into the battery casing is connected to a negative electrode current collector.

[0009] A battery current collector is fixedly provided on the inner wall of the battery casing.

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

[0011] Furthermore, the positive current collector includes a positive current collector with a metal mesh sleeve structure, and the positive current collector has positive electrode material adsorbed in the mesh.

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

[0013] Furthermore, the positive current collector is made of copper, stainless steel or titanium alloy, and the mesh size of the positive current collector is 1~10mm and the thickness is 3~15mm.

[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 1 mm.

[0017] Furthermore, the battery casing is provided with an upper metal fixing plate, which is fixed to the top of the positive current collector, and the outer edge of the upper metal fixing plate is welded to the inner wall of the battery casing.

[0018] Furthermore, the battery casing is provided with an annular lower metal strip, which is welded to the bottom of the battery casing. An annular groove is formed between the lower metal strip and the battery casing, and the bottom of the positive current collector is confined within the annular groove.

[0019] Furthermore, both the upper metal fixing plate and the lower metal baffle are made of stainless steel.

[0020] The beneficial effects of this novel liquid metal battery are as follows: The positive electrode current collector of the liquid metal battery is a metal mesh sleeve structure. The positive electrode material is supported and bound within a small area of ​​the metal mesh structure, avoiding the formation of large-area intermetallic compounds during charging and discharging that would cause arching due to stress accumulation. This prevents short circuits with the negative electrode, extends service life, and reduces the thickness of the electrolyte layer between the positive and negative electrodes. Furthermore, the vertical electrode arrangement of this novel liquid metal battery ensures that performance is not affected even if the battery is tilted, reducing the requirement for battery levelness. In addition, this structure facilitates the stacking of multiple electrode layers within the same sealed battery casing, which is beneficial for improving the stability of high-capacity batteries. Attached Figure Description

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

[0022] Figure 2 This is a charge-discharge curve diagram of a novel liquid metal battery according to an embodiment of this utility model;

[0023] Figure 3 This is a cycle performance diagram of a novel liquid metal battery at different rates according to an embodiment of this utility model;

[0024] In the diagram: 1-battery casing, 2-positive current collector, 3-upper metal fixing plate, 4-lower metal baffle, 5-electrolyte, 6-negative current collector, 7-insulator, 8-electrode rod. 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 novel liquid metal battery according to an embodiment of the present invention includes a battery casing 1, an electrode rod 8, 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 8 extends into the battery housing 1 through the mounting hole, and the upper end of the electrode rod 8 is also provided with a limiting cap. The electrode rod 8 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 electrode rod 8 extends into the outer wall of the battery housing 1 and 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 the porous structure of the negative electrode current collector adsorbs negative electrode material.

[0029] The inner wall of the battery casing 1 is fixedly provided with a positive electrode current collector 2. The positive electrode current collector 2 includes a positive electrode current collector with a metal mesh square sleeve structure. Positive electrode material is adsorbed in the mesh of the positive electrode current collector.

[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 end of the positive current collector 2 and the upper end of the negative current collector 6. The distance between the negative current collector 6 and the bottom of the battery casing is 3~10mm, and the distance between it and the positive current collector 2 is 3~15mm.

[0031] In the aforementioned structure, the positive electrode current collector is a square metal mesh sleeve structure. The positive electrode material is supported and confined within a small area of ​​the metal mesh structure, preventing the formation of large-area intermetallic compounds during charging and discharging that could bulge due to stress accumulation. This avoids short circuits with the negative electrode, extends service life, and reduces the thickness of the electrolyte layer between the positive and negative electrodes. Furthermore, the vertical electrode arrangement of this novel liquid metal battery ensures that performance is not affected even when the battery is tilted, reducing the requirement for battery levelness. In addition, this novel liquid metal battery facilitates multi-layer electrode stacking within a single sealed battery casing, which is beneficial for improving the stability of high-capacity batteries.

[0032] In a preferred embodiment, the positive electrode material is one or more of Bi, Sb, Pb, Sn, In, Te, and Ga. The negative electrode material is one or more of Li, Na, K, Mg, and Ca. The current collector material is copper, stainless steel, or titanium alloy. The mesh size of the positive current collector of the positive current collector 2 is 1-10 mm, and the thickness is 3-15 mm. The porosity of the porous structure of the negative current collector of the negative current collector 6 is 60-99%, and the pore size is less than 1 mm. The electrolyte 5 is a mixture of one or more of the halogen inorganic salts corresponding to the negative electrode material.

[0033] In a preferred embodiment, the battery casing 1 is provided with an upper metal fixing plate 3 and a lower metal baffle 4. Both the upper metal fixing plate 3 and the lower metal baffle 4 are rectangular ring structures, and the size of the lower metal baffle 4 is smaller than the size of the upper metal fixing plate 3.

[0034] The upper metal fixing piece 3 is fixed to the top of the positive electrode current collector 2. The outer edge of the upper metal fixing piece 3 is welded to the inner wall of the battery housing 1, and the upper metal fixing piece 3 is welded to the top wall of the positive electrode current collector 2. A lower metal baffle 4 is provided inside the battery housing 1. The lower metal baffle 4 is welded to the bottom of the battery housing 1, and an annular groove is formed between the lower metal baffle 4 and the battery housing 1. The bottom of the positive electrode current collector 2 is confined within the annular groove. The upper metal fixing piece 3 and the lower metal baffle 4 are used to firmly fix the positive electrode current collector 2 to the inner wall of the battery housing 1. Both the upper metal fixing piece 3 and the lower metal baffle 4 are made of stainless steel.

[0035] refer to Figure 2 and Figure 3 , Figure 2 and Figure 3 The figures show the charge-discharge curves of the novel liquid metal battery and its cycle performance at different rates. Figure 2 It can be seen that the current collector structure of the novel liquid metal battery 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 above-mentioned novel liquid metal battery is significantly improved under the same conditions.

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

[0037] S1: Weld the lower metal strip 4 to the bottom of the lower casing of the battery casing 1;

[0038] S2: Fix the negative current collector to the electrode rod 8, and then install the insulating part 7 on the hole of the metal cover; use the insulating part 7 to tightly connect the top of the electrode rod 8 to the cover.

[0039] S3: Place the positive electrode material on the positive electrode current collector and heat it until it melts and flows into the mesh of the positive electrode current collector to obtain the positive electrode current collector 2; after it is completely cooled, place it into the annular slot formed by the lower metal strip 4 in the battery cavity; then place the upper metal fixing plate 3 above the positive electrode current collector 2, first weld it to the side wall of the battery casing, and then weld it to the positive electrode current collector 2 to fix it.

[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 82% at 0.1C and 68% at 0.5C. After 30 cycles, the capacity showed virtually no degradation, 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 novel liquid metal battery, 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 outer wall of the portion of the electrode rod extending into the battery casing is connected to a negative electrode current collector. A battery current collector is fixedly provided on the inner wall of the battery casing. The electrolyte is filled inside the battery casing, and the height of the upper surface of the electrolyte exceeds the height of the upper end of the positive current collector and the upper end of the negative current collector.

2. A novel liquid metal battery as claimed in claim 1, wherein: The positive current collector includes a positive current collector with a metal mesh sleeve structure, and positive electrode material is adsorbed in the mesh of the positive current collector.

3. A novel liquid metal battery as claimed in claim 2, wherein: The positive current collector is made of copper, stainless steel or titanium alloy, and the mesh size of the positive current collector is 1~10mm and the thickness is 3~15mm.

4. A novel liquid metal battery as claimed in 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. A novel liquid metal battery as claimed in claim 4, wherein: The porosity of the negative current collector is 60-99%, and the pore size is less than 1 mm.

6. A novel liquid metal battery as claimed in claim 4, wherein: The battery casing is provided with an upper metal fixing plate, which is fixed to the top of the positive current collector, and the outer edge of the upper metal fixing plate is welded to the inner wall of the battery casing.

7. A novel liquid metal battery as claimed in claim 6, wherein: The battery casing has an annular lower metal strip inside, which is welded to the bottom of the battery casing. An annular groove is formed between the lower metal strip and the battery casing, and the bottom of the positive current collector is confined within the annular groove.

8. A novel liquid metal battery as claimed in claim 7, wherein: Both the upper metal fixing plate and the lower metal baffle are made of stainless steel.

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