Thermally regenerative cascade cell and method of making same
By using carbon-based cathode and anode electrodes in a thermal regenerative battery, combined with sulfur and cuprous sulfide, the corrosion problem of the anode electrode was solved, and the stability and power output of the battery were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING UNIV
- Filing Date
- 2023-07-31
- Publication Date
- 2026-06-23
AI Technical Summary
In existing thermal regenerable batteries, non-electrochemical corrosion occurs at the anode electrode, resulting in low anode coulombic efficiency and poor battery cycle performance and stability.
Carbon materials are used as the cathode and anode electrode substrates, and sulfur and cuprous sulfide are placed on the carbon materials. The anode chamber and cathode chamber are isolated by an ion exchange membrane. The electrode stability and conversion efficiency are improved through two-stage electrochemical reactions.
It effectively mitigates electrode structural damage, improves electrode stability and coulombic efficiency, and enhances battery power generation and cycle stability.
Smart Images
Figure CN116864713B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of thermal regenerable battery technology, and specifically to a thermal regenerable cascaded battery and its preparation method. Background Technology
[0002] A thermally regenerative battery (TRB) is a novel thermoelectric conversion device that recovers low-grade waste heat and converts it into electrical energy. The TRB system is a low-temperature thermoelectric conversion technology that indirectly utilizes low-temperature thermal energy, mainly consisting of an electricity generation section using an electrochemical cell and a thermal regeneration section utilizing low-temperature thermal energy.
[0003] In the power generation section of the battery, the TRB principle is similar to that of a redox battery. It relies on the potential difference generated by the redox couples at the cathode (Cu²⁺ / Cu and S / Cu₂S, etc.) and the anode (Cu(NH₃)₄²⁺ / Cu and Cu(en)₂²⁺ / Cu, etc.) to form a circuit and generate current. The anode and cathode are separated by an ion-exchange membrane to prevent mixing of active materials and ensure ion transport supporting the electrolyte, thus maintaining the solution's electroneutrality. Unlike redox batteries, to enable thermoelectric conversion, the products at the anode typically exist in the form of complexes. In the thermal regeneration section, the reacted anolyte is heated using low-temperature thermal energy, separating ligands (ammonia, ethylenediamine, and acetonitrile, etc.) from the anolyte to create a new cathode electrolyte. Simultaneously, the separated ligands are added to the reacted cathode electrolyte to obtain a new anolyte, which is then introduced into the previous anode and cathode chambers to begin the next batch of power generation.
[0004] Currently, thermally regenerable batteries exist, including traditional thermally regenerable ammonia batteries, all-aqueous TRBs, and non-aqueous TRBs. The key issue is that the final product on the anode electrode is the initial material for the cathode electrode, and vice versa. However, the thermal regeneration process only separates the products from the ligands in the electrolyte. The electrode conversion efficiency determines the cycle stability and lifespan of the TRB.
[0005] Previous studies have primarily used copper as the electrode in TRB (Transformer-Based Battery) power generation, with the reaction occurring on the metal electrode surface. However, non-electrochemical corrosion at the anode electrode leads to low anode coulombic efficiency, poor battery cycle life, and instability. Furthermore, the amount of active material loaded on the electrodes directly determines the battery capacity; a higher active material loading is beneficial for TRB to achieve higher energy density and thermal efficiency. Summary of the Invention
[0006] Therefore, it is necessary to address the problem that non-electrochemical corrosion of the anode electrode in existing thermal regenerable batteries leads to low anode coulombic efficiency, poor battery cycle performance, and poor stability, and to provide a thermal regenerable cascaded battery and its preparation method.
[0007] A thermally regenerable cascaded battery, comprising:
[0008] Reactor;
[0009] An ion exchange membrane is disposed inside the reactor, dividing the reactor into an anode chamber and a cathode chamber;
[0010] A cathode electrode, disposed in the cathode chamber and suspended in the cathode electrolyte, comprises a carbon material and sulfur disposed on the carbon material; and
[0011] An anode electrode is disposed in the anode chamber and suspended in the anode electrolyte. The anode electrode comprises a carbon material and cuprous sulfide and copper disposed on the carbon material.
[0012] In one embodiment, the reactor is provided with an anolyte injection port for the anolyte to enter the anolyte chamber and a cathode electrolyte injection port for the cathode electrolyte to be injected into the cathode chamber.
[0013] In one embodiment, the anolyte is a mixed solution of sulfate and ethylenediamine.
[0014] In one embodiment, the cathode electrolyte is a mixed solution of copper salt and sulfate.
[0015] In one embodiment, the cathode electrolyte is a mixed solution of CuSO4 and Li2SO4.
[0016] In one embodiment, the carbon material is carbon felt, carbon paper, or carbon cloth.
[0017] In one embodiment, the reactor further includes one or more seals for preventing electrolyte leakage from the reactor.
[0018] A method for preparing a thermally regenerable cascaded battery, comprising the following steps:
[0019] A cathode electrode is prepared, the cathode electrode comprising a carbon material and sulfur disposed on the carbon material;
[0020] An anode electrode is prepared, the anode electrode comprising a carbon material and cuprous sulfide and copper disposed on the carbon material;
[0021] A reactor is provided in which the cathode electrode is embedded in a cathode chamber and suspended in a cathode electrolyte, and the anode electrode is embedded in an anode chamber and suspended in an anode electrolyte.
[0022] In one embodiment, the step of preparing the cathode electrode specifically includes:
[0023] Sulfur powder, conductive carbon powder, and polyvinylidene fluoride are mixed, and N-methylpyrrolidone is added and ground to form a slurry. The slurry is then uniformly coated onto a carbon material substrate using a scraper, and finally dried to obtain the cathode electrode.
[0024] In one embodiment, the step of preparing the anode electrode specifically includes:
[0025] Using the cathode electrode as the working electrode and the copper foam electrode as the counter electrode and reference electrode, the cathode electrode and the copper foam electrode are placed in an electrolytic cell, and cathode electrolyte is added to submerge them. At the same time, an external electrochemical workstation is connected.
[0026] In the cathode electrolyte, sulfur on the cathode electrode and copper ions in the electrolyte are reduced to cuprous sulfide by current to obtain a carbon material cuprous sulfide electrode. Copper is then electrodeposited on the surface of the carbon material cuprous sulfide electrode to obtain the anode electrode.
[0027] The above-mentioned thermally regenerated cascaded battery and its preparation method have at least the following advantages:
[0028] Both the cathode and anode electrodes utilize carbon structures that do not react with the electrolyte as the electrode substrate. This prevents structural damage during the reaction process, ensuring the electrodes maintain a stable structure even after multiple reactions. This effectively mitigates non-electrochemical corrosion of the anode, improves conversion efficiency, and enhances electrode stability. The anode electrode features cuprous sulfide / copper, which promotes the stripping of copper in the anolyte, facilitating rapid copper stripping and reducing side reactions, thus significantly improving anode coulombic efficiency. Simultaneously, the coupled thermal regenerative cascade battery, with its two-stage electrochemical reactions, effectively increases the battery's power output. Attached Figure Description
[0029] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.
[0030] Figure 1 This is a schematic diagram of the structure of a thermally regenerated cascaded battery in one embodiment;
[0031] Figure 2 This is a flowchart of a method for preparing a thermally regenerated cascaded battery in one embodiment;
[0032] Figure 3 This is a schematic diagram of the fabrication of the cathode electrode;
[0033] Figure 4 A comparison of the power generation performance of a thermal regenerative cascade battery using a sulfur-carbon composite electrode, a thermal regenerative battery using a sulfur-carbon composite electrode, and a thermal regenerative ammonia battery using a foamed copper electrode.
[0034] Figure 5 A comparison of the discharge performance of thermal regenerative cascaded batteries using sulfur-carbon composite electrodes and thermal regenerative batteries using sulfur-carbon composite electrodes.
[0035] Figure 6 The cyclic discharge curves are for a thermally regenerable cascaded battery using a sulfur-carbon composite electrode.
[0036] Figure label:
[0037] 10-Reactor, 11-Cathode chamber, 12-Anode chamber, 13-Cathode electrolyte injection hole, 14-Anode electrolyte injection hole, 15-Cathode chamber, 16-Cathode end plate, 17-Anode chamber, 18-Anode end plate, 20-Ion exchange membrane, 30-Cathode electrode, 40-Anode electrode, 50-External circuit, 60-Working electrode, 70-Counter electrode, 80-Electrolytic cell. Detailed Implementation
[0038] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention; therefore, the invention is not limited to the specific embodiments disclosed below.
[0039] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0041] Please see Figure 1 One embodiment of the thermal regenerative cascade battery includes a reactor 10, an ion exchange membrane 20, a cathode electrode 30, and an anode electrode 40.
[0042] Reactor 10 provides space for the electrochemical reaction. An ion exchange membrane 20 is disposed within reactor 10, dividing the reactor 10 cavity into a cathode chamber 11 and an anode chamber 12. The anode chamber 12 contains an anolyte, and the cathode chamber 11 contains a catholyte. A cathode electrode 30 is disposed in the cathode chamber 11 and suspended in the catholyte. The cathode electrode 30 comprises carbon material and sulfur disposed on the carbon material. An anode electrode 40 is disposed in the anode chamber 12 and suspended in the anolyte. The anode electrode 40 comprises carbon material and cuprous sulfide and copper disposed on the carbon material.
[0043] In the aforementioned thermal regenerative cascaded battery, sulfur on the cathode electrode 30 gains electrons and is reduced to cuprous sulfide. Subsequently, copper ions in the solution further capture electrons and undergo electrodeposition on the surface of the cuprous sulfide. Copper on the anode electrode 40 loses electrons and is oxidized, forming a complex with ethylenediamine in the anolyte. Then, the cuprous sulfide continues to lose electrons and is oxidized to copper ions and elemental sulfur. During the electrochemical reaction, electrons migrate from the anode electrode 40 to the cathode electrode 30 through the external circuit 50, forming a stable current.
[0044] In one embodiment, the reactor 10 is provided with a cathode electrolyte injection hole 13 and an anode electrolyte injection hole 14, wherein the anode electrolyte is injected into the anode chamber 12 through the anode electrolyte injection hole 14, and the cathode electrolyte is injected into the cathode chamber 11 through the cathode electrolyte injection hole 13.
[0045] In one embodiment, the reactor 10 includes a cathode housing 15, a cathode end plate 16, an anode housing 17, and an anode end plate 18. An ion exchange membrane 20 separates the cathode housing 15 and the anode housing 17. The cathode end plate 16 encloses the cathode chamber 11, and the anode end plate 18 encloses the anode chamber 12. A cathode electrolyte injection port 13 is formed on the cathode housing 15, and an anode electrolyte injection port 14 is formed on the anode housing 17.
[0046] In one embodiment, the reactor 10 body further includes one or more sealing elements for preventing electrolyte leakage from the reactor 10. Specifically, the sealing element is a gasket, and gaskets are provided between the cathode end plate 16 and the cathode housing 15, the anode end plate 18 and the anode housing 17, the ion exchange membrane 20 and the cathode housing 15, and the ion exchange membrane 20 and the anode housing 17 to prevent electrolyte leakage.
[0047] In one embodiment, the anolyte is a mixed solution of sulfate and ethylenediamine. Specifically, the anolyte is a mixed solution of Li₂SO₄ and ethylenediamine. In one embodiment, the catholyte is a mixed solution of copper salt and sulfate. Specifically, the catholyte is a mixed solution of CuSO₄ and Li₂SO₄. It is understood that in other embodiments, the specific types of sulfate and copper salt can be flexibly selected as needed.
[0048] In one embodiment, the carbon material can be carbon paper, carbon cloth, carbon felt, carbon cotton, carbon foam, carbon black, carbon mesh, activated carbon, graphite, porous graphite, graphite powder, graphite particles, graphite fiber, etc. Specifically, in this embodiment, the carbon material is carbon cloth. The ion exchange membrane 20 is an anion exchange membrane (AEM).
[0049] The working principle of the above-mentioned thermal regenerative cascaded battery is as follows:
[0050] Cathode chamber 11 and anode chamber 12 are separated by an ion exchange membrane 20. Because the anolyte contains ethylenediamine, the copper plating on the surface of anode electrode 40 first undergoes a complexation reaction with ethylenediamine, generating electrons and copper-ethylenediamine complex ions. Then, cuprous sulfide loses electrons and reacts with ethylenediamine to form a copper-ethylenediamine complex and elemental sulfur. The generated electrons are transferred to cathode electrode 30 through external circuit 50. The sulfur on cathode electrode 30 gains electrons and is reduced to cuprous sulfide. Subsequently, copper ions in the solution further capture electrons, undergoing a reduction reaction to generate elemental copper, which is deposited on the surface of cathode electrode 30. Anions in the anode and cathode migrate through anion exchange membrane 20, forming an ion current and a circuit loop. The battery cathode and anode reactions are as follows:
[0051] Anode reaction:
[0052] ①Cu(s) + 2en(l) – 2e – →Cu(en)2 2+ (l)
[0053] ②Cu2S(s)+4en(l)–4e – →2Cu(en)2 2+ (l)+S(s)
[0054] Cathode reaction:
[0055] ①S(s)+2Cu 2+ +4e – →Cu2S(s)
[0056] ②Cu 2+ +2e – →Cu(s)
[0057] The battery continuously generates electricity through the reaction at cathode electrode 30 and anode electrode 40. The reaction stops only when the ethylenediamine in the anolyte or the copper ions in the cathode electrode 30 are depleted. During the reaction, the concentration of the copper-ammonia complex in the anolyte continuously increases, while the copper ions in the cathode electrolyte are continuously reduced to a lower concentration at cathode electrode 30. Furthermore, the total loading of cuprous sulfide and copper on anode electrode 40 also affects battery power generation; the battery stops generating electricity when both cuprous sulfide and copper are depleted.
[0058] Please see Figure 2 The present invention also provides a method for preparing a thermally regenerated cascaded battery, used to prepare the aforementioned thermally regenerated cascaded battery. Specifically, the preparation method includes the following steps:
[0059] Step S110: Prepare a cathode electrode 30, which includes a carbon material and sulfur disposed on the carbon material.
[0060] Specifically, sulfur powder, conductive carbon powder, and polyvinylidene fluoride are mixed, and an appropriate amount of N-methylpyrrolidone (NMP) is added and ground to form a slurry. The slurry is then uniformly coated onto a carbon cloth substrate using a scraper, and finally dried to obtain the cathode electrode 30. In one embodiment, the mass ratio of sulfur powder, conductive carbon powder, and polyvinylidene fluoride is 7:2:1.
[0061] Step S120: Prepare an anode electrode 40, which includes a carbon material and cuprous sulfide and copper disposed on the carbon material.
[0062] Please refer to the following: Figure 3 Specifically, the cathode electrode 30 is used as the working electrode 60, and the foamed copper electrode is used as the counter electrode 70 and reference electrode. These are placed in an electrolytic cell 80, and the cell is submerged by adding cathode electrolyte, while simultaneously connecting an external electrochemical workstation. In the cathode electrolyte, sulfur on the cathode electrode 30 and copper ions in the electrolyte are reduced to cuprous sulfide using a small current, resulting in a carbon cloth-supported cuprous sulfide electrode. Further, copper is electrodeposited on the surface of the carbon cloth-supported cuprous sulfide electrode to obtain the anode electrode 40.
[0063] Step S130: Provide reactor 10, embed cathode electrode 30 into cathode chamber 11 and suspend it in cathode electrolyte, and embed anode electrode 40 into anode chamber 12 and suspend it in anode electrolyte.
[0064] Specifically, reactor 10 includes a cathode shell 15, a cathode end plate 16, an anode shell 17, and an anode end plate 18. The cathode shell 15 and anode shell 17 are respectively disposed on the left and right sides of the ion exchange membrane 20. The cathode chamber 11 and anode chamber 12 are respectively filled with cathode electrolyte and anolyte. A cathode electrolyte injection hole 13 is provided on the upper side of the cathode shell 15, and the cathode electrode 30 is embedded in the cathode chamber 11 and in close contact with the anion exchange membrane 20. An anode electrolyte injection hole 14 is provided on the upper side of the anode shell 17, and the anode electrode 40 is embedded in the anode chamber 12 and in close contact with the anion exchange membrane 20. The cathode end plate 16 and anode end plate 18 are respectively disposed on the outer sides of the cathode chamber 11 and anode chamber 12, completing the establishment of a thermally regenerable cascaded battery.
[0065] The aforementioned thermal regenerative cascade battery and its preparation method utilize carbon structures as electrode substrates for both the cathode electrode 30 and the anode electrode 40, which do not react with the electrolyte. This prevents structural damage during the reaction process, ensuring the electrodes maintain a stable structure even after multiple reactions. This effectively mitigates non-electrochemical corrosion of the anode, improves electrode conversion efficiency, and enhances electrode stability. The anode electrode 40 features cuprous sulfide / copper, which promotes the stripping process of copper in the anolyte, enabling rapid copper stripping and reducing side reactions, thus effectively improving anode coulombic efficiency. Simultaneously, both the cathode electrode 30 and the anode electrode 40 undergo two stages of electrochemical reactions. The coupled two-stage electrochemical reaction in the thermal regenerative cascade battery effectively increases the battery's power output.
[0066] The advantages of the thermally regenerated cascaded battery of the present invention are illustrated below through a comparison of three operating conditions:
[0067]
[0068] By comparison Figure 4 The operating conditions show that the maximum performance of the thermal regenerative cascade battery and the thermal regenerative battery using sulfur-carbon composite electrodes is higher than that of the thermal regenerative ammonia battery using foamed copper electrodes, by 77% and 27%, respectively. Furthermore, the open-circuit voltages of the thermal regenerative cascade battery and the thermal regenerative battery using sulfur-carbon composite electrodes are 890mV and 650mV, respectively, which are higher than those of the thermal regenerative ammonia battery using foamed copper electrodes. This indicates that the thermal regenerative cascade battery and the thermal regenerative battery using sulfur-carbon composite electrodes have higher open-circuit voltages and higher maximum power output.
[0069] Figure 5To compare the power generation performance of a thermal regenerative cascade battery using a sulfur-carbon composite electrode and a thermal regenerative battery using the same electrode, it was found that the anode electrode 40 of the thermal regenerative cascade battery using the sulfur-carbon composite electrode has a certain amount of metallic copper plated on the surface of copper sulfide supported on carbon cloth, which adds a first-stage electrochemical reaction, resulting in a significant improvement in the battery's capacity and energy density. Meanwhile, according to... Figure 6 The capacity and current density of the thermal regeneration cascade battery using sulfur-carbon composite electrodes did not show significant decay within 20 cycles, indicating that the thermal regeneration cascade battery using sulfur-carbon composite electrodes has good power generation stability.
[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.
Claims
1. A thermally regenerable cascaded battery, characterized in that, include: Reactor; An ion exchange membrane is disposed inside the reactor, dividing the reactor into an anode chamber and a cathode chamber; A cathode electrode is disposed in the cathode chamber and suspended in the cathode electrolyte, the cathode electrode comprising a carbon material and sulfur disposed on the carbon material; and An anode electrode is disposed in the anode chamber and suspended in the anode electrolyte. The anode electrode comprises a carbon material and cuprous sulfide and copper disposed on the carbon material.
2. The thermally regenerable cascaded battery according to claim 1, characterized in that, The reactor is provided with an anolyte injection port for the anolyte to enter the anolyte chamber and a cathode electrolyte injection port for the cathode electrolyte to be injected into the cathode chamber.
3. The thermally regenerable cascaded battery according to claim 1, characterized in that, The anolyte is a mixed solution of sulfate and ethylenediamine.
4. The thermally regenerable cascaded battery according to claim 1, characterized in that, The cathode electrolyte is a mixed solution of copper salt and sulfate.
5. The thermally regenerable cascaded battery according to claim 4, characterized in that, The cathode electrolyte is a mixed solution of CuSO4 and Li2SO4.
6. The thermally regenerable cascaded battery according to claim 1, characterized in that, The carbon material is carbon felt, carbon paper, or carbon cloth.
7. The thermally regenerable cascaded battery according to claim 1, characterized in that, The reactor also includes one or more seals for preventing electrolyte leakage from the reactor.
8. A method for preparing a thermally regenerable cascaded battery, used to prepare the thermally regenerable cascaded battery as described in any one of claims 1-7, characterized in that, Includes the following steps: A cathode electrode is prepared, the cathode electrode comprising a carbon material and sulfur disposed on the carbon material; An anode electrode is prepared, the anode electrode comprising a carbon material and cuprous sulfide and copper disposed on the carbon material; A reactor is provided in which the cathode electrode is embedded in a cathode chamber and suspended in a cathode electrolyte, and the anode electrode is embedded in an anode chamber and suspended in an anode electrolyte.
9. The method for preparing a thermally regenerable cascaded battery according to claim 8, characterized in that, The specific steps for preparing the cathode electrode are as follows: Sulfur powder, conductive carbon powder, and polyvinylidene fluoride are mixed, and N-methylpyrrolidone is added and ground to form a slurry. The slurry is then uniformly coated onto a carbon material substrate using a scraper, and finally dried to obtain the cathode electrode.
10. The method for preparing a thermally regenerable cascaded battery according to claim 8, characterized in that, The specific steps for preparing the anode electrode are as follows: Using the cathode electrode as the working electrode and the copper foam electrode as the counter electrode and reference electrode, the cathode electrode and the copper foam electrode are placed in an electrolytic cell, and cathode electrolyte is added to submerge them. At the same time, an external electrochemical workstation is connected. In the cathode electrolyte, sulfur on the cathode electrode and copper ions in the electrolyte are reduced to cuprous sulfide by current to obtain a carbon material cuprous sulfide electrode. Copper is then electrodeposited on the surface of the carbon material cuprous sulfide electrode to obtain the anode electrode.