Liquid metal battery

Abstract

The invention provides a liquid metal battery, and relates to the technical field of battery structures, the liquid metal battery comprises a positive electrode shell, a positive electrode cover plate, a negative electrode current collector, foam metal and an electrode sleeve assembly; the positive pole cover plate fixedly covers the positive pole shell, the electrode sleeve assembly comprises an outer sleeve and an electrode core rod arranged in the outer sleeve, an insulating sleeve is arranged between the inner wall of the outer sleeve and the outer wall of the outer sleeve, and the foam metal is fixedly connected to the lower surface of the current collecting half plate. The battery structure has the beneficial effects that the outer sleeve and the electrode core rod of the battery structure are positioned on the outer side of the positive electrode shell and are isolated by the insulating sleeve, so that positive and negative electrode materials of a liquid metal battery can be arranged in the positive electrode shell in parallel, the internal space volume of the battery is utilized to the maximum extent, the energy density of the battery is improved, and the service life of the battery is prolonged. And the lower end of the outer sleeve is completely immersed in the electrolyte, so that the insulating sleeve is prevented from being eroded by negative electrode metal steam, and the service life of the battery sealing insulating part is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery structures, in particular to a liquid metal battery. Background Art

[0002] Liquid metal battery cells are mainly composed of negative electrodes, positive electrodes, electrolytes and battery structural parts. The negative electrode of the battery is often a single substance or alloy of alkali metal or alkaline earth metal, the positive electrode is generally a transition metal single substance, alloy, or other compound that can form an alloy with the negative electrode and has a certain potential difference with the negative electrode, and the electrolyte is an inorganic salt or mixture corresponding to the negative electrode metal. When the liquid metal battery is in operation, the negative electrode, positive electrode and electrolyte are all liquid. The three are self-stratified due to their different densities and mutual immiscibility. The upper layer is the negative electrode liquid metal with the lowest density, the middle layer is the liquid electrolyte, and the lower layer is the liquid metal positive electrode with high density. During discharge, the negative electrode liquid metal loses electrons and an oxidation reaction occurs. The electrons flow to the positive electrode through the external circuit, forming negative electrode metal ions that move through the electrolyte layer to the positive electrode and undergo an alloying reaction on the positive electrode side. The charging process is the opposite.

[0003] At present, liquid metal batteries still have some problems. Specifically, the volume energy density of single cells is low, the internal space volume of the battery is wasted, and it is not conducive to battery group management; the positive and negative insulating ceramics are easily corroded, causing the battery to fail due to sealing problems. Some researchers have adopted liquid sealing salt to protect the sealed insulating parts, but this will increase the number of steps in the battery preparation process, and the positive electrode material has poor spreading ability inside the battery shell, making the battery performance unstable.

[0004] To this end, building a liquid metal battery that can effectively utilize the internal space of the battery, extend the service life of the sealing insulating parts, and improve the stability of the battery is a key research and development goal for technical personnel in this field. Summary of the invention

[0005] In view of this, in order to make full use of the internal space of the liquid metal battery, extend the service life of the sealing insulation parts in the liquid metal battery, and improve the stability of the liquid metal battery, the present invention provides a liquid metal battery, including a positive electrode shell, a positive electrode cover plate, a negative electrode current collector, a foam metal and an electrode sleeve assembly;

[0006] The positive electrode cover plate is fixedly covered on the positive electrode shell to form a closed battery cavity in the positive electrode shell; a fixing hole is provided on the positive electrode cover plate;

[0007] The electrode sleeve assembly comprises an outer sleeve and an electrode core rod arranged in the outer sleeve, an insulating sleeve is arranged between the inner wall of the outer sleeve and the outer wall of the outer sleeve, the outer sleeve is located in the fixing hole, and the outer sleeve is fixedly connected to the positive electrode cover plate.

[0008] A downwardly concave bending groove is provided in the middle of the negative electrode current collector, so that the negative electrode current collector forms a current collecting half plate on both sides of the bending groove, the lower end of the electrode core rod is fixedly connected in the bending groove, and the two foam metals are fixedly connected to the lower surface of the current collecting half plate respectively;

[0009] The battery cavity is filled with electrolyte, and the electrolyte immerses the foam metal.

[0010] Furthermore, the positive electrode shell is a metal box body without a cover and with an open upper end, the positive electrode cover plate is a metal rectangular plate, and the edge of the positive electrode cover plate is fixedly connected to the edge of the opening of the positive electrode shell, thereby closing the opening of the positive electrode shell.

[0011] Furthermore, an assembly step is provided at the opening of the positive electrode shell, the positive electrode cover plate is embedded in the assembly step at the opening of the positive electrode shell, and the positive electrode cover plate is welded to the positive electrode shell.

[0012] Furthermore, the lower end of the outer sleeve passes through the positive electrode cover plate and extends into the battery cavity, and the electrolyte immerses the lower end of the outer sleeve.

[0013] Furthermore, it also includes a plurality of fastening bolts, the foam metal is a rectangular plate structure, the collecting half plate is provided with a fixing through hole, the foam metal is provided with an installation through hole, and the upper end of the fastening bolt passes through the fixing through hole from below and extends into the fixing through hole, thereby fixing the foam metal on the collecting half plate.

[0014] Furthermore, negative electrode material is adsorbed inside the foam metal.

[0015] Furthermore, an assembly through hole is provided in the middle of the bending groove, and the lower end of the electrode core rod is fixed in the assembly through hole.

[0016] Furthermore, a plurality of partition strips protruding upward are provided at the bottom of the positive electrode shell, and the partition strips divide the bottom of the positive electrode shell into a plurality of partition grids, and the partition grids are filled with positive electrode materials.

[0017] Furthermore, the positive electrode shell, the positive electrode cover plate, and the outer sleeve are all made of stainless steel, and the thickness of the positive electrode shell, the positive electrode cover plate, and the outer sleeve are all 0.5 to 3 mm.

[0018] Furthermore, the distance between the upper surface of the negative electrode current collector and the lower surface of the positive electrode cover plate is 1 to 4 mm.

[0019] The beneficial effects of a liquid metal battery of the present invention are:

[0020] (1) The liquid metal battery comprises a positive electrode shell, a positive electrode cover plate, a negative electrode current collector, a foam metal and an electrode sleeve assembly; the positive electrode cover plate is fixedly covered on the positive electrode shell, the electrode sleeve assembly comprises an outer sleeve and an electrode core rod arranged in the outer sleeve, an insulating sleeve is arranged between the inner wall of the outer sleeve and the outer wall of the outer sleeve, the outer sleeve is fixedly connected to the positive electrode cover plate, the lower end of the electrode core rod is fixedly connected to the bending groove, and the two foam metals are respectively fixedly connected to the lower surface of the current collector half plate; the battery cavity is filled with electrolyte, and the electrolyte immerses the foam metal. The positive and negative electrode connection ends of the liquid metal battery structure are the outer sleeve and the electrode core rod respectively, the outer sleeve and the electrode core rod are located outside the positive electrode shell, and are separated by the insulating sleeve, so that the positive and negative electrode materials of the liquid metal battery are arranged in parallel in the positive electrode shell, so that the internal space volume of the battery can be maximized and the battery energy density can be improved while ensuring safety, and the rectangular block structure of the liquid metal battery can be conveniently stacked in series and parallel, which is convenient for grouping.

[0021] (2) The lower end of the outer sleeve of the liquid metal battery is completely immersed in the electrolyte, ensuring that during the operation of the battery, the negative electrode metal vapor in the battery will not enter the gap between the outer sleeve and the electrode core rod, and the insulating sleeve will not be corroded by the negative electrode metal vapor, thereby extending the service life of the battery sealing insulation parts.

[0022] (3) The bottom of the positive electrode shell of the liquid metal battery is divided into partitions by partition strips, and the positive electrode material is filled in the partitions. This avoids the problem of poor spreading at the bottom of the battery shell due to the poor wettability of the positive electrode material, thereby effectively improving the uniformity of the distribution of the positive electrode material at the bottom of the battery shell and increasing the effective area during the charge and discharge process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of a liquid metal battery according to an embodiment of the present invention.

[0024] Figure 2 It is a top view of a positive electrode shell of a liquid metal battery according to an embodiment of the present invention.

[0025] In the above figure: 1-positive electrode shell, 11-assembly step, 12-partition bar, 13-partition grid, 2-positive electrode cover plate, 3-negative electrode current collector, 4-outer sleeve, 41-bending groove, 5-electrode core rod, 6-insulating sleeve, 7-foam metal, 71-fastening bolt, 8-positive electrode material. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0027] Please refer to Figure 1 to Figure 2A liquid metal battery of the present invention comprises a positive electrode shell 1, a positive electrode cover plate 2, a negative electrode current collector 3, a foam metal 7 and an electrode sleeve assembly.

[0028] The positive electrode cover plate 2 is fixedly covered on the positive electrode housing 1 so that a closed battery cavity is formed in the positive electrode housing 1; a fixing hole is provided on the positive electrode cover plate 2;

[0029] The electrode sleeve assembly includes an outer sleeve 4 and an electrode core rod 5 arranged in the outer sleeve 4, an insulating sleeve 6 is provided between the inner wall of the outer sleeve 4 and the outer wall of the outer sleeve 4, the outer sleeve 4 is located in the fixing hole, and the outer sleeve 4 is fixedly connected to the positive electrode cover plate 2.

[0030] A downwardly concave bending groove 41 is provided in the middle of the negative electrode current collecting sheet 3, so that the negative electrode current collecting sheet 3 forms a current collecting half plate on both sides of the bending groove 41, wherein the bending groove 41 is formed by bending the negative electrode current collecting sheet 3, and the lower end of the electrode core rod 5 is fixedly connected in the bending groove 41, and the two foam metals 7 are respectively fixedly connected to the lower surface of the current collecting half plate.

[0031] The battery cavity is filled with electrolyte, and the electrolyte submerges the foam metal 7 .

[0032] In a preferred embodiment, the positive electrode housing 1 is a metal box body without a cover and with an upper end open, and the edge of the positive electrode cover plate 2 is fixedly connected to the edge of the opening of the positive electrode housing 1, thereby closing the opening of the positive electrode housing.

[0033] In a preferred embodiment, an assembly step 11 is provided at the opening of the positive electrode housing 1 , the positive electrode cover plate 2 is embedded in the assembly step 11 at the opening of the positive electrode housing 1 , and the positive electrode cover plate 2 is welded to the positive electrode housing 1 .

[0034] In a preferred embodiment, the lower end of the outer sleeve 4 extends through the positive electrode cover plate 2 into the battery cavity, and the electrolyte immerses the lower end of the outer sleeve 4. This ensures that during the operation of the battery, the negative electrode metal vapor in the battery will not enter the gap between the outer sleeve and the electrode core rod, and the insulating sleeve will not be corroded by the negative electrode metal vapor, thereby extending the service life of the battery sealing insulation.

[0035] In a preferred embodiment, the foam metal 7 is a rectangular plate structure, the current collecting half plate is provided with a fixing through hole, the inner wall of the fixing through hole is provided with an internal thread, a fastening bolt 71 is threadedly connected in the fixing through hole, a mounting through hole is provided on the foam metal 7, the fastening bolt 71 passes through the mounting through hole of the foam metal 7 from below and extends into the fixing through hole, and the fastening bolt 71 fixes the foam metal 7 to the current collecting half plate by threaded connection. In order to prevent the negative electrode material from being concentrated on the end face of the bolt cap of the fastening bolt 71 during the charging process, the fastening bolt 71 needs to be completely screwed into the foam metal 7 during the connection process of the foam metal 7.

[0036] In a preferred embodiment, the foam metal 7 has negative electrode material adsorbed therein, and the negative electrode material is metallic lithium.

[0037] In a preferred embodiment, an assembly through hole is provided in the middle of the bending groove 41, and the lower end of the electrode core rod 5 is fixed in the assembly through hole. The electrode core rod 5 is fixed in the assembly through hole by welding.

[0038] In a preferred embodiment, a plurality of upwardly protruding partition strips 12 are provided at the bottom of the positive electrode shell 1, and a plurality of partition grids 13 are formed at the partition strips 12 at the bottom of the positive electrode shell 1. The partition grids 13 are filled with positive electrode materials, and the distance between the lower surface of the foam metal and the upper surface of the positive electrode material is 1 to 15 mm. If this distance is set too small, the battery stability is affected. If it is set too large, the battery performance is reduced, and the internal volume of the battery is increased, thereby increasing the amount of electrolyte, which greatly increases the battery mass and is not conducive to the improvement of the battery capacity density.

[0039] In a preferred embodiment, the positive electrode shell 1, the positive electrode cover plate 2, and the outer sleeve 4 are all made of stainless steel, and the thickness of the positive electrode shell 1, the positive electrode cover plate 2, and the outer sleeve 4 are all 0.5-3 mm. If the thickness of these parts is too thick, the battery energy density will be reduced, and if it is too low, it will easily affect the structural strength. The electrode core rod is made of one of stainless steel, oxygen-free copper, titanium alloy or sealing alloy, and the negative electrode current collector is made of stainless steel, carbon structural steel, pure copper and copper alloy or titanium alloy. The thickness is between 0.5 and 2 mm. If it is too thin, the threaded hole cannot be processed, and if it is too thick, it is not conducive to bending processing and reducing the battery energy density; the foam metal is foam nickel, foam iron, and foam copper-iron-nickel alloy; the insulating sleeve is a round tube made of alumina ceramic, beryllium oxide ceramic, aluminum nitride ceramic or PZT ceramic; the fastening bolt is made of one of stainless steel, carbon structural steel, copper and copper alloy.

[0040] In a preferred embodiment, the distance between the upper surface of the negative electrode current collector 3 and the lower surface of the positive electrode cover plate 2 is 1 to 4 mm, so that the thickness of the entire liquid metal battery can be as small as possible while ensuring the safety of the battery, thereby maximizing the utilization of the internal space volume of the battery and improving the battery energy density. At the same time, the positive electrode cover plate 2 is a metal rectangular plate, and the main structure of the entire liquid metal battery is a rectangular block. When the batteries are densely stacked in series and parallel, the space can be effectively utilized to facilitate grouping.

[0041] In this document, the directional words such as front, back, top, and bottom are defined by the positions of the components in the drawings and the positions of the components relative to each other, and are only for the sake of clarity and convenience in expressing the technical solution. It should be understood that the use of the directional words should not limit the scope of protection claimed in this application.

[0042] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A liquid metal battery, characterized in that: It includes a positive electrode shell, a positive electrode cover plate, a negative electrode current collector, a foam metal and an electrode sleeve assembly; The positive electrode cover plate is fixedly covered on the positive electrode shell to form a closed battery cavity in the positive electrode shell; a fixing hole is provided on the positive electrode cover plate; The electrode sleeve assembly comprises an outer sleeve and an electrode core rod arranged in the outer sleeve, an insulating sleeve is arranged between the inner wall of the outer sleeve and the outer wall of the outer sleeve, the outer sleeve is located in the fixing hole, and the outer sleeve is fixedly connected to the positive electrode cover plate. A downwardly concave bending groove is provided in the middle of the negative electrode current collector, so that the negative electrode current collector forms a current collecting half plate on both sides of the bending groove, the lower end of the electrode core rod is fixedly connected in the bending groove, and the two foam metals are fixedly connected to the lower surface of the current collecting half plate respectively; The battery cavity is filled with electrolyte, and the electrolyte immerses the foam metal.

2. A liquid metal battery according to claim 1, characterized in that: The positive electrode shell is a metal box body without a cover and with an upper end open, and the positive electrode cover plate is a metal rectangular plate. The edge of the positive electrode cover plate is fixedly connected to the edge of the opening of the positive electrode shell, thereby closing the opening of the positive electrode shell.

3. A liquid metal battery according to claim 2, characterized in that: An assembly step is provided at the opening of the positive electrode shell, the positive electrode cover plate is embedded in the assembly step at the opening of the positive electrode shell, and the positive electrode cover plate is welded to the positive electrode shell.

4. The liquid metal battery according to claim 1, characterized in that: The lower end of the outer sleeve passes through the positive electrode cover plate and extends into the battery cavity, and the electrolyte immerses the lower end of the outer sleeve.

5. The liquid metal battery according to claim 1, characterized in that: It also includes a plurality of fastening bolts, the foam metal is a rectangular plate structure, a fixing through hole is provided on the current collecting half plate, an installation through hole is provided on the foam metal, and the upper end of the fastening bolt passes through the fixing through hole from below and extends into the fixing through hole, thereby fixing the foam metal on the current collecting half plate.

6. The liquid metal battery according to claim 1, characterized in that: The negative electrode material is adsorbed inside the foam metal.

7. The liquid metal battery according to claim 1, characterized in that: An assembly through hole is provided in the middle of the bending groove, and the lower end of the electrode core rod is fixed in the assembly through hole.

8. The liquid metal battery according to claim 1, characterized in that: The bottom of the positive electrode shell is provided with a plurality of partition strips protruding upwards, and the partition strips separate the bottom of the positive electrode shell into a plurality of partition grids, and the partition grids are filled with positive electrode materials.

9. The liquid metal battery according to claim 1, characterized in that: The positive electrode shell, the positive electrode cover plate and the outer sleeve are all made of stainless steel, and the thickness of the positive electrode shell, the positive electrode cover plate and the outer sleeve are all 0.5-3 mm.

10. The liquid metal battery according to claim 1, characterized in that: The distance between the upper surface of the negative electrode current collector and the lower surface of the positive electrode cover plate is 1 to 4 mm.

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