A water-based thermoelectric cell pn conversion method based on micelle self-assembly effect and a water-based thermoelectric cell

Abstract

The present invention provides a p-n conversion method for an aqueous thermogalvanic cell based on the micelle self-assembly effect and an aqueous thermogalvanic cell, belonging to the technical field of thermoelectric cells. The p-n conversion type aqueous thermogalvanic cell based on the micelle self-assembly effect of the present invention comprises a mold, a filling liquid, a cold-side electrode, and a hot-side electrode; both ends of the mold are open; the mold contains the filling liquid, and the openings at both ends of the mold are respectively encapsulated with the cold-side electrode and the hot-side electrode; the temperature of the cold-side electrode is maintained at 15 °C; the filling liquid is a mixture of a KI / KI3 electrolyte solution and a polyethylene glycol-polyacrylate copolymer. By doping with a thermosensitive polymer, the concentration of I3 ‑ ions can be selectively regulated, and the n-type I ‑ / I3 ‑ system can be converted into a p-type. The original I ‑ / I3 ‑ redox couple has a negative thermopower and is defined as n-type, but it can be converted with the addition of a certain content of polyethylene glycol-polyacrylate copolymer and shows a p-type thermopower.

Description

Technical Field

[0001] The invention belongs to the technical field of thermoelectric cells, and in particular relates to a water-based thermoelectric cell pn conversion method based on micelle self-assembly effect and a water-based thermoelectric cell. Background Art

[0002] In the industrial production process, more than 60% of the energy is usually lost in the form of waste heat, especially low-grade waste heat (temperature below 100°C). These waste heat sources are widely present in various production links, such as cooling water, tail gas and exhaust gas. Due to the low energy density and low temperature, traditional waste heat recovery technology is often inefficient when facing low-grade waste heat and difficult to use effectively. Although existing technical solutions, such as organic Rankine cycle and heat pump technology, have been applied, they still face problems such as high cost, low efficiency and limited scope of application. Therefore, how to efficiently and economically recover and utilize this part of waste heat resources has become a key technical challenge to improve industrial energy utilization and reduce energy waste.

[0003] As a new type of energy conversion device, thermoelectric cells can directly convert low-grade waste heat into electrical energy and have broad application prospects. Its working principle is usually based on the thermoelectric effect or other thermal energy conversion mechanisms, using temperature differences to generate current. Compared with traditional waste heat recovery technology, thermoelectric cells have the advantages of simple structure, no moving parts, and a wide temperature range, and are particularly suitable for the recovery of low-temperature waste heat.

[0004] Thermogenic cells are based on redox reactions between two electrodes at different temperatures. The oxidation reaction releases electrons to one electrode, while the reduction reaction absorbs electrons from the other electrode. Electrons are conducted through an external circuit, while the redox pairs inside the electrolyte diffuse and migrate between the electrodes to keep the system working stably. When a temperature difference exists, thermal energy can be directly converted into electrical energy. However, the currently available thermogenic battery systems are very limited. For example, the redox pairs of the p-type are mainly ferrocyanide and ferrocyanide ions. In addition, the coordinated matching of the redox potential, operating temperature window and output power of the p-type and n-type systems restricts the integration and application of thermogenic cells. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide an aqueous thermoelectric cell pn conversion method and an aqueous thermoelectric cell based on the micelle self-assembly effect, which expands the types of existing p-type redox couples and realizes the pn-type conversion of the thermoelectric cell.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] In the first aspect, the present invention provides a method for pn conversion of an aqueous thermoelectric cell based on micelle self-assembly effect, using a mixture of KI / KI3 electrolyte and polyethylene glycol-polyacrylate copolymer as the battery filling liquid; and maintaining the temperature of the cold side electrode at 15°C, and the hot side electrode absorbing heat;

[0008] The concentration of the KI / KI3 electrolyte is 5 mM; the mass ratio of the KI / KI3 electrolyte to the polyethylene glycol-polyacrylate copolymer is 100:5-12.

[0009] By adopting the above technical solution, the battery behaves as a p-type battery when the temperature of the hot side electrode is less than 25°C (reduction reaction occurs on the cold side (I3 - +2e→3I - ), oxidation reaction occurs on the hot side (3I - -2e→I3 - ); When the temperature of the hot side electrode is greater than 25°C, it behaves as n-type (reduction reaction occurs on the hot side (I3 - +2e→3I - ), oxidation reaction occurs on the cold side (3I - -2e→I3 - ), thus realizing the conversion of pn.

[0010] The present invention provides a pn conversion type aqueous thermoelectric cell based on micelle self-assembly effect, comprising a mold, a filling liquid, a cold side electrode, and a hot side electrode;

[0011] The two ends of the mold are open;

[0012] The mold contains a filling liquid, and the openings at both ends of the mold are respectively encapsulated with a cold side electrode and a hot side electrode; the temperature of the cold side electrode is maintained at 15°C;

[0013] The filling liquid is a mixture of KI / KI3 electrolyte and polyethylene glycol-polyacrylate copolymer.

[0014] Preferably, the concentration of the KI / KI3 electrolyte is 5 mM; the mass ratio of the KI / KI3 electrolyte to the polyethylene glycol-polyacrylate copolymer is 100:5-12.

[0015] Preferably, the cold-side electrode and the hot-side electrode are made of graphite.

[0016] Preferably, the mold is an acrylic mold.

[0017] Preferably, the mold and the electrode

[0018] In a second aspect, the present invention provides a method for preparing the above-mentioned pn conversion type aqueous thermoelectric cell, comprising the following preparation steps:

[0019] 5-12 wt % of polyethylene glycol-polyacrylate copolymer is added to the KI / KI3 electrolyte, stirred evenly, and then packaged using a mold, a cold side electrode and a hot side electrode; the temperature of the cold side electrode is maintained at 15°C.

[0020] Contains at least the following beneficial technical effects:

[0021] (1) The present invention expands the types of existing p-type redox couples and realizes pn conversion.

[0022] (2) The present invention provides a new idea for the collection of low-grade thermal energy. By doping with thermosensitive polymers, the I3 - Ion concentration can be - / I3 - The system is converted to p-type, and the original I - / I3 - The redox couple has negative thermal power and is defined as n-type, but can be converted to p-type thermal power with the addition of a certain amount of polyethylene glycol-polyacrylate copolymer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The output power curve of the thermoelectric cell prepared in the example under a temperature difference of 10K.

[0024] Figure 2 This is the thermal power test diagram.

[0025] Figure 3 is the corresponding thermal power fitting diagram.

[0026] Figure 4 This is the output performance diagram at different polyethylene glycol-polyacrylate copolymer contents.

[0027] Figure 5 This is the output power diagram of p-type (12wt%) and n-type (1wt%) batteries in π-type series connection under a temperature difference of 10K.

[0028] Figure 6 This is a physical picture of multiple thermoelectric cells connected in series. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0030] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0031] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the main idea or essential features of the present invention. Therefore, from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0032] In addition, it should be understood that although this specification is described according to the implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. These other implementation modes are also covered within the protection scope of the present invention.

[0033] It should also be understood that the specific embodiments described above are only used to explain the present invention, and the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the protection scope of the present invention / invention.

[0034] Example

[0035] This embodiment provides a pn conversion type aqueous thermoelectric cell based on micelle self-assembly effect, and the preparation method is as follows:

[0036] 12 wt % of polyethylene glycol-polyacrylate copolymer was added to the KI / KI3 electrolyte and stirred evenly, and then packaged using a mold, a cold side electrode and a hot side electrode; the temperature of the cold side electrode was maintained at 15°C.

[0037] Test example

[0038] In this experiment, the thermal power was measured using a temperature difference platform. The hot side was heated by a Peltier patch and a temperature difference was applied. The cold side was controlled by water cooling and kept at a constant temperature. A K-type thermocouple was used to measure the temperature, and the corresponding data was recorded by a multimeter (Keithley DAQ6510). The multimeter was also used to record the open circuit voltage. The LSV program of the electrochemical workstation was used to test the output power of the battery under a certain temperature difference.

[0039] The output power of the thermoelectric cell prepared in the embodiment under a temperature difference of 10K (the temperature of the cold side electrode is 15°C) is as follows: Figure 1 shown.

[0040] Thermal power test Figure 2 As shown, by keeping the cold side temperature at 15°C and increasing the hot side electrode temperature, the open circuit thermoelectric potential generated by the battery first decreases and then increases, where the red curve represents the change in temperature difference and the black curve represents the change in voltage.

[0041] The corresponding thermal power is fitted as Figure 3 As shown (p-type thermal power is positive, n-type thermal power is negative)

[0042] The output performance of thermoelectric cells under a certain temperature difference with different polyethylene glycol-polyacrylate copolymer contents is shown in Figure 2. Figure 4 Shown

[0043] The same preparation method as in the embodiment, a p-type (12wt%) and an n-type (1wt%) battery π-type series connection under a temperature difference of 10K (15-25°C) output power is as follows Figure 5 shown.

[0044] It shows that the battery prepared by the present invention realizes the conversion from p-type to n-type.

[0045] The heat source battery of the present invention can be used in combination with multiple batteries. Figure 6 .

[0046] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for pn conversion of aqueous thermoelectric cells based on micelle self-assembly effect, characterized in that: A mixture of KI / KI3 electrolyte and polyethylene glycol-polyacrylate copolymer is used as the battery filling liquid; the temperature of the cold side electrode is maintained at 15°C, and the hot side electrode absorbs the heat source; The concentration of the KI / KI3 electrolyte is 5 mM; the mass ratio of the KI / KI3 electrolyte to the polyethylene glycol-polyacrylate copolymer is 100:5-12.

2. A pn ​​conversion aqueous thermoelectric cell based on micelle self-assembly effect, characterized in that: Including mold, filling liquid, cold side electrode, hot side electrode; The two ends of the mold are open; The mold contains a filling liquid, and the openings at both ends of the mold are respectively encapsulated with a cold side electrode and a hot side electrode; the temperature of the cold side electrode is maintained at 15°C; The filling liquid is a mixture of KI / KI3 electrolyte and polyethylene glycol-polyacrylate copolymer.

3. The pn conversion type aqueous thermoelectric cell according to claim 2, characterized in that: The concentration of the KI / KI3 electrolyte is 5 mM; the mass ratio of the KI / KI3 electrolyte to the polyethylene glycol-polyacrylate copolymer is 100:5-12.

4. The pn conversion type aqueous thermoelectric cell according to claim 2, characterized in that: The cold side electrode and the hot side electrode are made of graphite plates.

5. The pn conversion type aqueous thermoelectric cell according to claim 2, characterized in that: The mold is an acrylic mold.

6. The method for preparing a pn conversion type aqueous thermoelectric cell according to any one of claims 2 to 5, characterized in that: The method comprises the following preparation steps: 5-12 wt % of polyethylene glycol-polyacrylate copolymer is added to KI / KI3 electrolyte, stirred evenly, and then packaged using a mold, a cold side electrode and a hot side electrode; the temperature of the cold side electrode is maintained at 15°C.

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