Density-induced self-stratification for membrane-free thermal regeneration batteries

Abstract

The present invention discloses a membraneless thermal regeneration battery with density-induced self-stratification, comprising a reactor shell, an inlet end, a liquid inlet end and an outlet end. A cathode chamber and an anode chamber are provided in the reactor shell, a cathode electrode is provided in the cathode chamber, and an anode electrode is provided in the anode chamber. A cathode electrolyte is introduced into the cathode chamber through the inlet end, an intermediate solution capable of electrochemically reacting with the anode electrode is introduced into the liquid inlet end, the intermediate solution is mixed with the cathode electrolyte to form an anode electrolyte, and the anode electrolyte flows out through the outlet end. The density of the intermediate solution is less than that of the cathode electrolyte, so that the cathode electrolyte and the anode electrolyte form an interface through the density difference. In the above-mentioned membraneless thermal regeneration battery with density-induced self-stratification, the cathode electrolyte and the anode electrolyte form an interface due to the density difference to form a virtual membrane, so as to replace the expensive ion exchange membrane, significantly reducing the construction cost of the battery, and this membraneless thermal regeneration battery can quickly realize the conversion of cathode and cathode by inversion.

Description

Technical Field

[0001] The invention relates to the technical field of thermal regeneration batteries, and in particular to a density-induced self-stratified membrane-free thermal regeneration battery. Background Art

[0002] Low-grade waste heat (<130℃) generated in industrial processes is considered a thermal pollutant and a huge energy loss. Utilizing efficient waste heat recovery is essential to reduce greenhouse gas emissions and is expected to bring potential economic and environmental benefits.

[0003] In order to achieve effective waste heat recovery, some electrochemical-based thermoelectric conversion system technologies have been developed in recent years. Among them, thermally regenerative battery (TRB) is a highly efficient energy conversion technology. Compared with other thermoelectric conversion systems, TRB has higher output capacity, which brings hope for its practical application in the future. The TRB in existing research is mainly composed of electrode end plates, cathode chambers, cathode electrodes, anion exchange membranes, anode chambers and anode electrodes.

[0004] Although this technology has developed rapidly, it still faces some challenges. The main function of the anion exchange membrane in TRB is to block Cu2+ and NH3 in the anode liquid from entering the cathode liquid. However, during the long-term power generation process, the ion selective membrane (AEM) has difficulty preventing the penetration of NH3 during long-term operation. The ammonia concentration gradient on both sides of the anion exchange membrane is large, which will aggravate the crossover of ammonia. The crossover of ammonia from the anode to the cathode leads to a decrease in the ammonia concentration in the anode and causes a mixed cathode potential, resulting in a significant performance degradation. In addition, the anion exchange membrane is expensive, which directly leads to a significant increase in the construction cost of the battery, hindering the further development and application of TRB. Summary of the invention

[0005] Based on this, it is necessary to provide a density-induced self-stratified membraneless thermal regeneration battery for existing thermal regeneration batteries, where the ion-selective membrane is difficult to prevent the penetration of NH3, resulting in significant performance degradation and high cost.

[0006] A density-induced self-stratified membrane-less thermal regeneration battery, comprising:

[0007] A reactor shell, in which a cathode chamber and an anode chamber are arranged, wherein the anode chamber is located at the upper part of the cathode chamber, a cathode electrode is arranged in the cathode chamber, and an anode electrode is arranged in the anode chamber;

[0008] An inlet end is communicated with the cathode chamber, and the cathode electrolyte is introduced into the cathode chamber through the inlet end;

[0009] a liquid inlet end connected between the cathode chamber and the anode chamber, into which an intermediate solution capable of electrochemically reacting with the anode electrode is introduced, and the intermediate solution is mixed with the cathode electrolyte to form an anode electrolyte; and

[0010] An outlet port is communicated with the anode chamber, and the mixed anode electrolyte flows out through the outlet port;

[0011] The density of the intermediate solution is less than that of the cathode electrolyte, so that the cathode electrolyte and the anode electrolyte form an interface through the density difference.

[0012] In one embodiment, the cathode electrode and the anode electrode are metal electrodes; or

[0013] The cathode electrode and the anode electrode both include a carbon electrode and a metal supported thereon.

[0014] In one of the embodiments, the anode electrode and the metal used for the anode electrode are copper, zinc, silver, nickel or cobalt.

[0015] In one embodiment, the intermediate solution is ammonia, ethylenediamine, ethylenediaminetetraacetic acid or acetonitrile.

[0016] In one embodiment, the reactor shell includes a first shell and a second shell, the cathode chamber is disposed in the first shell, the anode chamber is disposed in the second shell, and the second shell and the first shell are spliced ​​to each other up and down.

[0017] In one embodiment, a first mounting plate is disposed outside the first shell, a second mounting plate is disposed outside the second shell, and a connecting structure connects the first mounting plate and the second mounting plate.

[0018] In one embodiment, the cathode electrode and the anode electrode are symmetrically and parallelly arranged along the liquid inlet end.

[0019] In one embodiment, the cathode electrolyte is a mixed solution of CuSO4 and (NH4)2SO4.

[0020] In one embodiment, the inlet end, the outlet end and the liquid inlet end are all provided with flow diversion channels.

[0021] In one embodiment, the diversion channel includes an annular channel and a diversion port, the inlet end, the outlet end and the liquid inlet end are connected to the corresponding annular channel, the diversion port is located on the inner side of the annular channel, and a plurality of the diversion ports are evenly arranged along the circumferential direction of the annular channel.

[0022] In the above-mentioned density-induced self-stratification membraneless thermal regeneration battery, the density of the intermediate solution is less than the density of the cathode electrolyte, so that the density of the anode electrolyte formed by the mixture is also less than the density of the cathode electrolyte. Due to the density difference, the cathode electrolyte and the anode electrolyte form a clear and stable interface at the mixing point, so that the anode and cathode electrolytes can self-stratify to form a virtual membrane to replace the expensive ion exchange membrane, avoiding problems such as ammonia penetration and membrane aging, achieving stable power generation of the thermal regeneration battery, and significantly reducing the construction cost of the battery. In addition, this membraneless thermal regeneration battery can quickly achieve anode and cathode conversion by inversion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0024] Figure 1 A schematic diagram of the structure of a membraneless thermal regeneration battery with density-induced self-stratification in one embodiment;

[0025] Figure 2 This is a schematic diagram of the power generation performance of the thermal regeneration battery;

[0026] Figure 3 This is a schematic diagram of the power generation curve of the thermal regeneration battery;

[0027] Figure 4 Schematic diagram of the power generation performance of the anode and cathode switching battery.

[0028] Reference numerals:

[0029] 10-reactor shell, 12-cathode chamber, 14-anode chamber, 16-cathode electrode, 18-anode electrode, 110-first shell, 120-second shell, 130-first mounting plate, 140-second mounting plate, 150-connecting structure, 20-inlet end, 30-liquid inlet end, 40-outlet end, 42-annular flow channel, 44-diversion port. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the invention is not limited by the specific implementation disclosed below.

[0031] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0033] See also Figure 1 A density-induced self-stratified membraneless thermal regeneration cell in one embodiment includes a reactor shell 10 , an inlet end 20 , a liquid inlet end 30 , and an outlet end 40 .

[0034] A cathode chamber 12 and an anode chamber 14 are provided in the reactor shell 10. The anode chamber 14 is located at the upper part of the cathode chamber 12, and the anode chamber 14 and the cathode chamber 12 are connected to each other. A cathode electrode 16 is provided in the cathode chamber 12, and an anode electrode 18 is provided in the anode chamber 14. The shape of the reactor shell 10 can be specifically set as needed, such as a cylindrical shape or a polygonal column shape.

[0035] In one embodiment, the reactor shell 10 includes a first shell 110 and a second shell 120, the cathode chamber 12 is disposed in the first shell 110, the anode chamber 14 is disposed in the second shell 120, and the second shell 120 is stacked on the first shell 110, so that the second shell 120 and the first shell 110 are spliced ​​with each other in an upper and lower manner. The reactor shell 10 is formed by splicing two parts, which can facilitate the disassembly, assembly and replacement of the cathode electrode 16 and the anode electrode 18.

[0036] On the basis of the above embodiment, further, the first housing 110 is provided with a first mounting plate 130, the second housing 120 is provided with a second mounting plate 140, and the connecting structure 150 connects the first mounting plate 130 and the second mounting plate 140, so as to maintain the sealing effect at the joint of the first housing 110 and the second housing 120, and ensure that the seal does not leak. Specifically, the connecting structure 150 can be a clevis bolt. Of course, in other embodiments, the connecting structure 150 can also adopt other structures that utilize connection, such as a connecting screw, etc.

[0037] It is understandable that in other embodiments, the reactor shell 10 may also be an integral structure, and the cathode electrode 16 and the anode electrode 18 are pre-installed in the reactor shell 10 .

[0038] In one embodiment, the cathode electrode 16 and the anode electrode 18 have the same structure, and the anode electrode 18 and the anode electrode 18 can be metal electrodes. In other embodiments, the cathode electrode 16 and the anode electrode 18 may not all be made of metal, and the cathode electrode 16 and the anode electrode 18 include a carbon electrode and a metal loaded thereon, which can reduce the metal material. Specifically, the metal used in the cathode electrode 16 and the anode electrode 18 can be copper, zinc, silver, nickel or cobalt. In this embodiment, the metal used in the cathode electrode 16 and the anode electrode 18 is copper.

[0039] The inlet end 20 is connected to the cathode chamber 12, and the cathode electrolyte is passed into the cathode chamber 12 through the inlet end 20. The liquid inlet end 30 is connected between the cathode chamber 12 and the anode chamber 14, and an intermediate solution capable of electrochemically reacting with the anode electrode 18 is passed into the liquid inlet end 30. After the cathode electrolyte fills the cathode chamber 12, it is mixed with the intermediate solution flowing into the liquid inlet end 30 to form the anode electrolyte. The water outlet end is connected to the anode chamber 14, and the mixed anode electrolyte flows out through the outlet end 40. Among them, the density of the intermediate solution is less than the density of the cathode electrolyte, so that the cathode electrolyte and the anode electrolyte form an interface through the sealing difference.

[0040] In one embodiment, the inlet port 20 is located at the bottom of the reactor shell 10, and the inlet port 20 is connected to the first shell 110. The outlet port 40 is located at the top of the reactor shell 10, and the outlet port 40 is connected to the second shell 120. The cathode electrode 16 and the anode electrode 18 are symmetrically and parallelly arranged along the liquid inlet end 30, which can ensure the power generation performance of the thermal regeneration battery, and can also facilitate inversion to realize the conversion of positive and negative electrodes.

[0041] In one embodiment, the intermediate solution is a solution with a lower density, and the intermediate solution can be ammonia, ethylenediamine, ethylenediaminetetraacetic acid or acetonitrile, and the cathode electrolyte is a mixed solution of CuSO4 and (NH4)2SO4. Specifically in this embodiment, the intermediate solution is ammonia water, the mass fraction of the ammonia water solution is 25%, and the cathode electrolyte is a mixed solution of 0.2M CuSO4 and 1M (NH4)2SO4.

[0042] In one embodiment, the inlet end 20, the outlet end 40 and the liquid inlet end 30 are all provided with a shunt flow channel, and the shunt flow channel can make the electrolyte flow evenly, and the shunt design of the liquid inlet end 30 is conducive to the formation of the electrolyte interface between the cathode and cathode. Specifically, the shunt flow channel includes an annular flow channel 42 and a shunt port 44, the inlet end 20, the water outlet end and the liquid inlet end 30 are connected to the corresponding annular flow channel 42, the shunt port 44 is located on the inner side of the annular flow channel 42, and a plurality of shunt ports 44 are designed, and the plurality of shunt ports 44 are evenly spaced and arranged along the circumferential direction of the annular flow channel 42.

[0043] The working principle of the above-mentioned density-induced self-stratification membraneless thermal regeneration battery is specifically as follows:

[0044] The cathode electrolyte enters from the lower inlet port 20. After the cathode electrolyte fills the cathode chamber 12, it mixes with the ammonia entering from the middle liquid inlet port 30 and mixes with the ammonia water to form the anolyte. The anolyte flows out from the upper outlet port 40. Since the density of the ammonia water is lower than that of the cathode electrolyte, the density of the mixed anolyte is reduced. Due to the density difference between the cathode electrolyte and the anode electrolyte, a stable electrolyte interface can be formed in the middle to separate each other.

[0045] Due to the presence of ammonia in the liquid of the anode electrode 18, a corrosion reaction occurs with the anode electrode 18 to generate a metal ammine complex and electrons. The electrons flow from the external circuit to the cathode electrode 16. The Cu2+ in the cathode electrolyte combines with the electrons to produce an electroplating reaction and is deposited on the surface of the cathode electrode 16. The anions in the electrolyte migrate to form an ion current, forming a current loop.

[0046] Through the cathode and anode electrode 18 reaction, the battery can continuously generate electricity. The polarization curve and power density curve of the battery are as follows: Figure 2 As shown in Figure 2, the maximum power density of the battery reaches 5.3mW / cm2. And because the self-stratified cathode and anode electrolytes formed based on the density difference can effectively eliminate ammonia penetration, a stable power generation platform can be achieved during long-term power generation, such as Figure 3 As shown, the output voltage of the battery is stable above 180mV.

[0047] During the reaction, the concentration of copper ammonia complex in the cathode electrolyte increases continuously, and the reaction metal on the anode electrode 18 decreases continuously. The two electrodes need to be divided into the cathode electrode 16 and the anode electrode 18 in turn, which can effectively balance the quality of the cathode and cathode electrodes 18 and improve the stability of the electrodes. The battery structure can be inverted to quickly switch between the cathode and cathode, and the switching time is related to the flow rate of the electrolyte.

[0048] like Figure 4 As shown in Figure 2, when the electrolyte flow rate is 6 mL / min, the switching response time is about 40 s. Figure 4 As shown in ① and ②, by increasing the electrolyte flow rate to 12 mL / min, the switching response time can be shortened to 20 s, as shown in Figure 4 As shown in ③ and ④.

[0049] Finally, after the power generation is completed, the electrolyte will enter the thermal reactor device to use low-temperature thermal energy for thermal regeneration, generate ammonia and copper ion solution, and return to the reactor to generate electricity. Therefore, the density difference-induced self-stratified membraneless thermal regeneration battery can effectively convert low-temperature thermal energy into electrical energy and achieve high-power output thermoelectric conversion.

[0050] In the above-mentioned density-induced self-stratification membraneless thermal regeneration battery, the cathode electrolyte and the anode electrolyte form a clear and stable interface at the mixing point due to the density difference, and the anode and cathode electrolytes are self-stratified to form a virtual membrane to replace the expensive ion exchange membrane, avoiding problems such as ammonia penetration and membrane aging, achieving stable power generation of the thermal regeneration battery, and significantly reducing the construction cost of the battery. In addition, this membraneless thermal regeneration battery can quickly achieve anode and cathode conversion by inversion.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A density-induced self-stratified membraneless thermal regeneration battery, characterized in that: include: A reactor shell, in which a cathode chamber and an anode chamber are arranged, wherein the anode chamber is located at the upper part of the cathode chamber, a cathode electrode is arranged in the cathode chamber, and an anode electrode is arranged in the anode chamber; An inlet end is communicated with the cathode chamber, and the cathode electrolyte is introduced into the cathode chamber through the inlet end; A liquid inlet end is connected between the cathode chamber and the anode chamber, and an intermediate solution capable of electrochemically reacting with the anode electrode is introduced into the liquid inlet end, and the intermediate solution is mixed with the cathode electrolyte to form an anode electrolyte; and An outlet port is communicated with the anode chamber, and the mixed anode electrolyte flows out through the outlet port; wherein the density of the intermediate solution is less than the density of the cathode electrolyte, so that the cathode electrolyte and the anode electrolyte form an interface through the density difference; The intermediate solution is ammonia, ethylenediamine, ethylenediaminetetraacetic acid or acetonitrile.

2. The density-induced self-stratified membraneless thermal regeneration battery according to claim 1, characterized in that: The cathode electrode and the anode electrode are metal electrodes; or The cathode electrode and the anode electrode both include a carbon electrode and a metal supported thereon.

3. The density-induced self-stratified membraneless thermal regeneration battery according to claim 2, characterized in that: The metal used for the cathode electrode and the anode electrode is copper, zinc, silver, nickel or cobalt.

4. The density-induced self-stratified membraneless thermal regeneration battery according to claim 1, characterized in that: The reactor shell includes a first shell and a second shell. The cathode chamber is arranged in the first shell, and the anode chamber is arranged in the second shell. The second shell and the first shell are spliced ​​with each other in an up-and-down manner.

5. The density-induced self-stratified membraneless thermal regeneration battery according to claim 4, characterized in that: A first mounting plate is disposed outside the first shell, a second mounting plate is disposed outside the second shell, and a connecting structure connects the first mounting plate and the second mounting plate.

6. The density-induced self-stratified membraneless thermal regeneration battery according to claim 1, characterized in that: The cathode electrode and the anode electrode are symmetrically and parallelly arranged along the liquid inlet end.

7. The membraneless thermal regeneration battery with density-induced self-stratification according to claim 1, characterized in that: The cathode electrolyte is a mixed solution of CuSO4 and (NH4)2SO4.

8. The membraneless thermal regeneration battery with density-induced self-stratification according to claim 1, characterized in that: The inlet end, the outlet end and the liquid inlet end are all provided with diversion channels.

9. The density-induced self-stratified membraneless thermal regeneration battery according to claim 8, characterized in that: The diversion channel includes an annular channel and a diversion port. The inlet end, the outlet end and the liquid inlet end are connected to the corresponding annular channel. The diversion port is located on the inner side of the annular channel. Multiple diversion ports are evenly arranged along the circumferential direction of the annular channel.

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