Liquid Metal Battery

Abstract

The present invention discloses a liquid metal battery, comprising a shell, a top cover and a conductive crucible arranged in the shell, wherein the conductive crucible contains an electrolyte, one end of the shell is open, and the top cover is arranged at the open position; a positive electrode, a negative electrode and a negative electrode lead-out rod are arranged in the conductive crucible, the positive electrode is located at the bottom wall of the conductive crucible, the negative electrode is located in the electrolyte, one end of the negative electrode lead-out rod is inserted in the negative electrode, and the other end of the negative electrode lead-out rod is inserted in the top cover, and is connected and insulated with the top cover by an insulating member; at least one conductive partition is arranged on the bottom wall of the conductive crucible, and at least one conductive partition divides the positive electrode into at least two partitions, and any two adjacent partitions are connected to each other. The liquid metal battery of the present invention performs a partitioned and limited processing on the positive electrode, so that the positive electrode is divided into pieces, and the positive electrode is prevented from directly contacting the negative electrode and causing a short circuit. At the same time, the thickness of the electrolyte can be further adjusted to be thinner, and the battery energy efficiency is improved, and the battery performance is good.

Description

Technical Field

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

[0002] The scalability of batteries is an important criterion for measuring whether an energy storage technology can be widely used in the field of large-scale grid energy storage. As a battery technology for grid energy storage, the concept of liquid metal batteries was first proposed by Professor Sadoway's team at the Massachusetts Institute of Technology (MIT) in 2006. It has the advantages of being pollution-free, long life and low maintenance costs. Liquid metal batteries, specifically, convert chemical energy into electrical energy through the redox reaction of molten metal, i.e. liquid metal; in this battery working mode, the electrodes are all liquid metals, and the electrolyte is a molten inorganic salt. The electrodes and electrolytes are naturally layered due to their different densities and immiscibility. In theory, this three-layer liquid self-assembled structure avoids the complex process in room temperature energy storage batteries, making the scale-up of battery cells simpler.

[0003] However, in the actual proportional amplification process of battery cells, large-capacity (≥100Ah) battery cells are prone to short circuits and other life attenuation problems during the charging and discharging process. After the battery is cooled and cut open to observe the cross section, it is found that the main reason for the short circuit in the battery is that the uneven distribution of current density causes the positive electrode layer of the battery to bulge, that is, the positive electrode layer of the battery bulges upward and directly contacts the negative electrode current collector. In addition, the thickness of the electrolyte layer in liquid metal batteries is one of the main factors affecting battery performance. The thinner the electrolyte layer, the smaller the battery ohmic internal resistance and the better the battery performance. However, the thinner the electrolyte layer, the easier it is for the battery to short-circuit, and it is impossible to avoid battery short-circuiting while ensuring high battery performance. Summary of the invention

[0004] The main purpose of the present invention is to provide a liquid metal battery, aiming to solve the problem that the existing liquid metal batteries cannot avoid battery short circuit while ensuring battery high performance.

[0005] To achieve the above-mentioned purpose, the present invention proposes a liquid metal battery, comprising a shell, a top cover and a conductive crucible arranged in the shell, wherein the conductive crucible contains an electrolyte, one end of the shell is open, and the top cover is arranged on the open end; a positive electrode, a negative electrode and a negative electrode lead-out rod are arranged in the conductive crucible, the positive electrode is located on the bottom wall of the conductive crucible, the negative electrode is located in the electrolyte, one end of the negative electrode lead-out rod is inserted in the negative electrode, and the other end of the negative electrode lead-out rod is passed through the top cover, and is connected and insulated with the top cover by an insulating member; at least one conductive partition is arranged on the bottom wall of the conductive crucible, and at least one conductive partition divides the positive electrode into at least two partitions, and any two adjacent partitions are connected to each other.

[0006] Preferably, there are two conductive partitions, which are arranged to cross each other, and there is a gap between both ends of the conductive partition and the side wall of the conductive crucible.

[0007] Preferably, the bottom wall of the conductive crucible is circular, the conductive partition is strip-shaped, and two conductive partitions divide the positive electrode into four sector-shaped partitions.

[0008] Preferably, the intersection of the two conductive partitions coincides with the center position of the bottom wall of the conductive crucible.

[0009] Preferably, there are two conductive partitions, each of which is arranged in a non-closed ring shape, and there is a gap between each conductive partition and the side wall of the conductive crucible and between two conductive partitions.

[0010] Preferably, the bottom wall of the conductive crucible is circular, the conductive partition is a circular ring with an opening, and the two conductive partitions are respectively an outer conductive partition and an inner conductive partition, wherein the outer conductive partition surrounds the inner conductive partition, and the inner conductive partition and the outer conductive partition divide the positive electrode into a circular and two annular partitions.

[0011] Preferably, the center position of the outer conductive partition and the center position of the inner conductive partition both coincide with the center position of the bottom wall of the conductive crucible, and the opening of the outer conductive partition is staggered with the opening of the inner conductive partition.

[0012] Preferably, the height of the conductive separator is higher than the height of the positive electrode.

[0013] Preferably, the height of the conductive separator is H, and the height of the positive electrode is h, wherein 1.2h≤H≤1.6h.

[0014] Preferably, a tray is provided on the negative electrode lead-out rod near the top cover, the tray contains liquid sealing salt, and the insulating member extends into the liquid sealing salt.

[0015] In the liquid metal battery of the present invention, the bottom wall of the conductive crucible is provided with at least one conductive partition, and at least one conductive partition divides the positive electrode into at least two partitions, and any two adjacent partitions are interconnected, that is, the partitions are not completely isolated, and the partitions can flow between each other, that is, each partition is not independently arranged, so as to prevent each partition from acting alone with the negative electrode and causing a parallel phenomenon. The liquid metal battery of the present invention divides the positive electrode into at least two partitions by at least one partition, and performs a partition-limited treatment on the positive electrode, so that the positive electrode is divided into zero, and the overall positive electrode is improved due to uneven current density distribution. The phenomenon of the overall positive electrode bulging upward is improved, and the positive electrode is prevented from directly contacting the negative electrode and causing a short circuit. At the same time, the positive electrode is divided into at least two partitions by at least one partition, so that the fluctuation amplitude of the positive electrode metal interface is reduced, the distance between the positive electrode and the negative electrode can be reduced, the thickness of the electrolyte can be further adjusted to be thinner, and the ohmic internal resistance of the battery is reduced, which is helpful for the liquid metal battery monomer to be enlarged, the battery voltage is increased or stabilized, the battery energy efficiency is improved, the battery performance is good, and the battery service life is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 is a cross-sectional schematic diagram of a liquid metal battery according to an embodiment of the present invention;

[0018] Figure 2 It is a three-dimensional schematic diagram of a conductive crucible and a positive electrode in a liquid metal battery according to an embodiment of the present invention;

[0019] Figure 3 It is a three-dimensional schematic diagram of a conductive crucible and a positive electrode in a liquid metal battery according to another embodiment of the present invention.

[0020] Description of Figure Numbers:

[0021] Label name Label name 100 Liquid Metal Battery 6 negative electrode 1 case 7 Negative lead rod 2 Top cover 71 Limit block 3 Conductive crucible 8 Insulation 31 bottom wall 81 Metal Sheet 32 Sidewall 82 Ceramic ring 4 Electrolytes 83 Metal ring 5 positive electrode 9 Conductive separator 51 Partition 9a Internal conductive separator 51a Sector partition 9b External conductive separator 51b Circular partition 91 Opening 51c Inner ring partition 10 tray 51d Outer ring partition 101 Liquid sealing salt

[0022] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0025] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] In the present invention, the description of the directions such as "upper" and "lower" is as follows: Figure 1 The directions shown in the figure are for reference only and are used to explain the Figure 1 The relative position relationship between the components in the shown posture. If the specific posture changes, the directional indication will also change accordingly.

[0027] like Figures 1 to 3 As shown, the present invention proposes a liquid metal battery 100, which includes a shell 1, a top cover 2 and a conductive crucible 3, wherein one end of the shell 1 is open, and the top cover 2 is covered at the open position to close the open position, and the conductive crucible 3 is arranged in the shell 1, and the conductive crucible 3 contains an electrolyte 4, and the conductive crucible 3 is provided with a positive electrode 5, a negative electrode 6 and a negative electrode lead-out rod 7, the positive electrode 5 is located on the bottom wall 31 of the conductive crucible 3, the negative electrode 6 is located in the electrolyte 4, one end of the negative electrode lead-out rod 7 is inserted in the negative electrode 6, and the other end of the negative electrode lead-out rod 7 is passed through the top cover 2, and is connected and insulated with the top cover 2 through an insulating member 8; the bottom wall 31 of the conductive crucible 3 is provided with at least one conductive partition 9, and the at least one conductive partition 9 divides the positive electrode 5 into at least two partitions 51, and any two adjacent partitions 51 are connected to each other.

[0028] Specifically, in one embodiment, the shell 1 is a metal can with a closed bottom wall 31 and an open top, the top cover 2 is a metal part and is covered on the open top of the shell 1, and the conductive crucible 3 is used as the inner lining of the shell 1 and is only lined on the inner wall of the shell 1. The liquid metal battery 100 is provided with a negative electrode current collector, which is made of a porous metal foam material, and the metal of the negative electrode 6 is adsorbed in the porous metal foam. The lower end of the negative electrode lead-out rod 7 of this embodiment is inserted into the negative electrode current collector, and a through hole is opened at the center of the top cover 2, and an insulating member 8 is embedded in the through hole. The upper end of the negative electrode lead-out rod 7 is passed through the insulating member 8 and is connected and insulated with the insulating member 8. In a preferred embodiment, in order to facilitate the assembly between the insulating part 8, the negative lead-out rod 7 and the top cover 2, the insulating part 8 includes a metal plate 81, a ceramic ring 82 and a metal ring 83, wherein the metal ring 83 is embedded in the through hole of the top cover 2, and the ceramic ring 82 is connected to the top of the metal ring 83, and the metal plate 81 is provided on the top of the ceramic ring 82, and a limit block 71 is formed at the upper end of the negative lead-out rod 7, and the limit block 71 abuts against the top of the metal plate 81 to assemble the insulating part 8 with the negative lead-out rod 7 and the top cover 2.

[0029] In the liquid metal battery 100 of this embodiment, the bottom wall 31 of the conductive crucible 3 is provided with at least one conductive partition 9, and the at least one conductive partition 9 divides the positive electrode 5 into at least two partitions 51. Any two adjacent partitions 51 are interconnected, that is, the partitions 51 are not completely isolated, and the partitions 51 can flow with each other, that is, each partition 51 is not independently arranged, so as to prevent each partition 51 from acting alone with the negative electrode 6 and causing a parallel phenomenon. The liquid metal battery 100 of this embodiment divides the positive electrode 5 into at least two partitions 51 by at least one partition, and performs partition and confinement processing on the positive electrode 5, so that the positive electrode 5 is divided into parts, and the overall positive electrode 5 is improved due to uneven current density distribution. The phenomenon of the overall positive electrode 5 bulging upward is improved, and the positive electrode 5 is prevented from directly contacting the negative electrode 6 and causing a short circuit. At the same time, the positive electrode 5 is divided into at least two partitions 51 by at least one partition, so that the fluctuation amplitude of the metal interface of the positive electrode 5 is reduced, and the distance between the positive electrode 5 and the negative electrode 6 can be reduced, and the thickness of the electrolyte 4 can be further adjusted to be thinner, and the ohmic internal resistance of the battery is reduced, which is helpful for the liquid metal battery 100 monomer to be enlarged, increase or stabilize the battery voltage, improve the battery energy efficiency, and have good battery performance, and extend the battery life. In the prior art, the thickness of the electrolyte 4 in the liquid metal battery 100 is usually 15mm-20mm, and the thickness of the electrolyte 4 in the liquid metal battery 100 of this embodiment can be 8mm-12mm.

[0030] In the liquid metal battery 100 of this embodiment, the side wall 32 of the conductive crucible 3 is arranged around its bottom wall 31, and its bottom wall 31 can be circular, square, oval or any other shape. The side wall 32 of the conductive crucible 3 can be a cylinder, square cylinder, oval cylinder or any other shape matching the bottom wall 31 of the conductive crucible 3. The present invention does not limit the shape of the conductive crucible 3. The conductive partition 9 can be strip-shaped, arc-shaped, ring-shaped, wavy or any other shape. The conductive partition 9 only needs to divide the positive electrode 5 into different partitions 51. The present invention does not limit the shape and number of the conductive partition 9.

[0031] like Figure 2 As shown, in a preferred embodiment, there are two conductive partitions 9, which are arranged crosswise with each other, and there is a gap between both ends of the conductive partition 9 and the side wall 32 of the conductive crucible 3. The two conductive partitions 9 can be cross-shaped to divide the positive electrode 5 into four partitions 51. The two ends of the conductive partition 9 are not directly connected to the side wall 32 of the conductive crucible 3, but have a gap, so that the four partitions 51 can be connected to each other. The arrangement of the two conductive partitions 9 is simple in structure and easy to manufacture.

[0032] Furthermore, the bottom wall 31 of the conductive crucible 3 is circular, the conductive partition 9 is strip-shaped, and the two conductive partitions 9 divide the positive electrode 5 into four sector-shaped partitions 51. Figure 2 As shown, the two conductive partitions 9 cross each other perpendicularly, and four sector-shaped areas are formed between the two conductive partitions 9 and the side wall 32 of the conductive crucible 3, thereby dividing the positive electrode 5 into four sector-shaped partitions 51a.

[0033] Since the bulging of the positive electrode 5 is mainly concentrated in the central area of ​​the positive electrode 5, that is, the height of the bulging of the central area of ​​the positive electrode 5 is relatively high, the intersection of the two conductive partitions 9 in this embodiment coincides with the central position of the bottom wall 31 of the conductive crucible 3, so that the central area of ​​the positive electrode 5 is divided by the intersection of the two conductive partitions 9, which greatly improves the phenomenon that the central area of ​​the positive electrode 5 bulges upward, and improves the reliability of preventing the liquid metal battery 100 from short-circuiting. In this embodiment, the volumes of the four sector-shaped partitions 51a are consistent, and the current density distribution is relatively uniform, which further prevents the positive electrode 5 from bulging.

[0034] like Figure 3As shown, in another preferred embodiment, the number of the conductive partitions 9 is two, each conductive partition 9 is arranged in a non-closed ring shape, and there is a gap between each conductive partition 9 and the side wall 32 of the conductive crucible 3 and between the two conductive partitions 9. Specifically, each conductive partition 9 is arranged in a non-closed ring shape, and there is a gap between each conductive partition 9 and the side wall 32 of the conductive crucible 3 to prevent the conductive partition 9 from being directly connected to the side wall 32 of the conductive crucible 3 to form an independent partition 51, and there is also a gap between the two conductive partitions 9 to prevent the two conductive partitions 9 from crossing each other to form an independent partition 51, so that the partitions 51 are connected to each other, thereby preventing each partition 51 from acting alone with the negative electrode 6 and forming a parallel phenomenon.

[0035] Furthermore, the bottom wall 31 of the conductive crucible 3 is circular, the conductive partition 9 is a ring with an opening 91, and the two conductive partitions 9 are respectively an outer conductive partition 9b and an inner conductive partition 9a, wherein the outer conductive partition 9b surrounds the inner conductive partition 9a, and the inner conductive partition 9a and the outer conductive partition 9b divide the positive electrode 5 into a circular partition and two annular partitions 51. Specifically, as Figure 3 As shown, the outer conductive partition 9b and the inner conductive partition 9a are arranged concentrically, and the outer conductive partition 9b surrounds the outer conductive partition 9a, the inner area of ​​the inner conductive partition 9a forms a circular area, the inner conductive partition 9a and the outer conductive partition 9b form an annular area, and the outer conductive partition 9b and the side wall 32 of the conductive crucible 3 also form an annular area, thereby dividing the positive electrode 5 into a circular partition 51b and two annular partitions, with a simple structure and easy to manufacture. Among them, the two annular partitions are the inner annular partition 51c and the outer annular partition 51d, and the outer annular partition 51d surrounds the inner annular partition 51c.

[0036] Furthermore, the center position of the outer conductive partition 9b and the center position of the inner conductive partition 9a both coincide with the center position of the bottom wall 31 of the conductive crucible 3, and the opening 91 of the outer conductive partition 9b and the opening 91 of the inner conductive partition 9a are arranged in a staggered manner, so that the connection between the inner annular partition 51c and the outer annular partition 51d is arranged in a staggered manner with the connection between the inner annular partition 51c and the circular partition 51b, preventing the connection between the circular partition 51b, the inner annular partition 51c and the outer annular partition 51d from being relatively concentrated, preventing the positive electrode 5 from being arched, and improving the reliability of preventing the liquid metal battery 100 from being short-circuited. In this embodiment, the volumes of the circular partition 51b, the inner annular partition 51c and the outer annular partition 51d are consistent, and the current density distribution is relatively uniform, which further prevents the positive electrode 5 from being arched.

[0037] In this embodiment, the conductive partition 9 is integrally formed with the bottom wall 31 of the conductive crucible 3, which is not only convenient to manufacture but also omits the assembly step between the conductive partition 9 and the conductive crucible 3, thereby avoiding assembly errors between the conductive partition 9 and the conductive crucible 3.

[0038] In this embodiment, the height of the conductive separator 9 is higher than the height of the positive electrode 5, so that the conductive separator 9 can effectively divide the positive electrode 5. The height of the conductive separator 9 can be set according to actual needs. In this embodiment, there is no restriction on the height of the conductive separator 9. In a preferred embodiment, the height of the conductive separator 9 is H, and the height of the positive electrode 5 is h, wherein 1.2h≤H≤1.6h, that is, the height of the conductive separator 9 is 1.2 times to 1.6 times the height of the positive electrode 5, so that the reactants of the liquid metal battery 100 in the fully discharged state can also maintain the partition 51 state divided by the conductive separator 9.

[0039] In this embodiment, a tray 10 is provided on the negative electrode lead-out rod 7 near the top cover 2, and the tray 10 contains a liquid sealing salt 101, and the insulating member 8 extends into the liquid sealing salt 101. Specifically, Figure 1 As shown, the tray 10 of this embodiment is boxed and filled with liquid sealing salt 101. The top of the tray 10 is open, and the lower end of the insulating member 8 can extend into the liquid sealing salt 101, specifically, the metal ring 83 of the insulating member 8 extends into the liquid sealing salt 101. The liquid sealing salt 101 can isolate the gas in the conductive crucible 3 from contacting the ceramic ring 82, thereby preventing the ceramic ring 82 from being corroded and ensuring the insulation effect of the insulating member 8.

[0040] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A liquid metal battery, comprising a shell, a top cover and a conductive crucible arranged in the shell, wherein the conductive crucible contains electrolyte, one end of the shell is open, and the top cover is arranged at the open end; characterized in that: The conductive crucible is provided with a positive electrode, a negative electrode and a negative electrode lead-out rod, the positive electrode is located on the bottom wall of the conductive crucible, the negative electrode is located in the electrolyte, one end of the negative electrode lead-out rod is inserted into the negative electrode, and the other end of the negative electrode lead-out rod is passed through the top cover, and is connected and insulated with the top cover through an insulating member; the bottom wall of the conductive crucible is provided with at least one conductive partition, at least one conductive partition divides the positive electrode into at least two partitions, and any two adjacent partitions are connected to each other; The number of the conductive partitions is two, the two conductive partitions are arranged to cross each other, and there is a gap between both ends of the conductive partition and the side wall of the conductive crucible, and the intersection of the two conductive partitions coincides with the center position of the bottom wall of the conductive crucible; Or, the number of the conductive partitions is two, each of the conductive partitions is arranged in a non-closed ring shape, and there is a gap between each of the conductive partitions and the side wall of the conductive crucible and between the two conductive partitions, the two conductive partitions are an inner conductive partition and an outer conductive partition surrounding the inner conductive partition, the center position of the outer conductive partition and the center position of the inner conductive partition both coincide with the center position of the bottom wall of the conductive crucible, and the opening of the outer conductive partition is staggered with the opening of the inner conductive partition; The height of the conductive separator is higher than the height of the positive electrode. The height of the conductive separator is H, and the height of the positive electrode is h, wherein 1.2h≤H≤1.6h.

2. The liquid metal battery according to claim 1, characterized in that: The bottom wall of the conductive crucible is circular, the conductive partition is strip-shaped, and two conductive partitions divide the positive electrode into four sector-shaped partitions.

3. The liquid metal battery according to claim 1, characterized in that: The bottom wall of the conductive crucible is circular, the conductive partition is a circular ring with an opening, and the inner conductive partition and the outer conductive partition divide the positive electrode into a circular partition and two annular partitions.

4. The liquid metal battery according to any one of claims 1 to 3, characterized in that: A tray is arranged on the negative electrode lead-out rod near the top cover, the tray contains liquid sealing salt, and the insulating member extends into the liquid sealing salt.

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