New application of iodine as positive electrode material of chargeable and dischargeable seawater battery

Abstract

The invention discloses a novel application of iodine as a positive electrode material of a chargeable and dischargeable seawater battery. According to the invention, iodine is adopted as a positive electrode active material, energy storage is carried out in a deposition / dissolution (solid / liquid) mode by utilizing iodine / iodine ion redox pair, and the positive electrode material has the advantages of high specific capacity, high charging and discharging speed, good environmental protection property, relatively good cycling stability, proper potential range and the like, and can be used as a novel positive electrode material of a secondary seawater battery; and the method has important significance on a low-cost and high-performance electrochemical energy storage technology.

Description

Technical Field

[0001] The invention belongs to the field of electrochemical energy storage and new material applications, and specifically relates to new applications of iodine in the field of positive electrodes of rechargeable and dischargeable seawater batteries. Background Art

[0002] Early seawater batteries were mainly primary batteries (non-secondary batteries) and could not be repeatedly charged and discharged. Secondary seawater batteries are a new technology developed in recent years and are also one of the most ideal electrochemical energy storage technologies. They have the advantages of low cost, safety, and environmental protection, and are suitable for large-scale storage of renewable energy sources such as wind and solar energy. Currently, there are few types of cathode materials for developed secondary seawater batteries (also called rechargeable seawater batteries), mainly OER / ORR dual-effect catalysts (Adv. Mater., 2024, 2312343), Ag / AgCl, etc., but these materials have extremely large voltage polarization or are very expensive. Positive electrode materials such as Prussian blue have also been developed successively, but their capacity is still relatively low (Research, 2024, DOI: 10.34133 / research.0461). The development of low-cost, high-capacity cathode materials is of great significance for the practical application of secondary seawater batteries. At present, iodine is mainly used in zinc-iodine batteries, and the more common one is a one-electron reaction. So far, there is no report on the use of iodine in the production of secondary seawater battery cathode materials.

[0003] The present invention develops iodine as a positive electrode material for secondary seawater batteries, which has the advantages of high specific capacity, fast charge and discharge speed, good environmental protection, good cycle stability, and a suitable potential range. It is expected to be used as an energy storage material for marine equipment. Summary of the invention

[0004] The invention is applicable to the field of secondary seawater batteries, and uses iodine as the positive electrode material of the secondary seawater battery, including such modified materials. The invention is the first to apply iodine materials in the field of negative electrodes of secondary seawater batteries.

[0005] New use of iodine as positive electrode material for rechargeable seawater batteries.

[0006] Furthermore, in the positive electrode material, iodine is the only positive electrode active ingredient.

[0007] Furthermore, using natural seawater as the electrolyte, in the rechargeable and dischargeable seawater battery positive electrode material, the iodine forms an iodine / iodine ion redox pair to store energy through a deposition / dissolution (solid / liquid) manner.

[0008] A rechargeable seawater battery positive electrode material contains iodine. Further, iodine is used as the only positive electrode active component. The iodine can be directly purchased or prepared by electrodeposition.

[0009] A rechargeable and dischargeable seawater battery adopts any of the above-mentioned positive electrode materials.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: the positive electrode material provided by the present invention has the advantages of high specific capacity, good rate performance, high voltage, environmental protection, etc.; compared with conventional iodine-based batteries such as zinc-iodine batteries, the application of iodine / iodide ions to secondary seawater batteries can achieve a two-electron reaction without the need to add any toxic or harmful substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a scanning electron microscope photograph of the positive electrode of Example 1 of the present invention;

[0012] Figure 2 This is the constant current charge and discharge curve of the positive electrode of Example 1 of the present invention;

[0013] Figure 3 1 is the cyclic voltammetry curve of the positive electrode of Example 1 of the present invention; DETAILED DESCRIPTION

[0014] In order to make the purpose and technical route of the present invention clearer, the present invention is described in detail below in conjunction with embodiment. It should be noted that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of protection of the present invention. Other personnel can make some simple improvements or replacements based on the concept of the present invention. These improvements or replacement schemes also fall within the scope of protection of the present invention.

[0015] Example 1

[0016] Commercial activated carbon powder and polytetrafluoroethylene were mixed evenly in a mass ratio of 9:1, and the substrate was prepared by dry rolling. Then it was immersed in a 50 mL volume of 0.5 M ZnSO4 + 1 M KI mixed solution, and the zinc sheet was used as the negative electrode and the activated carbon composite electrode sheet as the positive electrode. The substrate was charged by constant current (20 mA / cm 2 , constant current deposition for 6 min) to deposit iodine onto the positive electrode to obtain a working electrode, the morphology of which is as follows Figure 1 The energy storage performance was tested in a three-electrode system, with natural seawater as the electrolyte, silver / silver chloride electrode as the reference electrode, and Pt sheet as the counter electrode. Figure 2 As shown, the discharge capacity at a current density of 2.55 A / g is as high as 157.1 mAh / g. Figure 3The cyclic voltammetry curve shows that it has the characteristics of repeated charge and discharge; and two pairs of obvious "oxidation / reduction" peaks can be observed, indicating a two-electron reaction. During the charge and discharge process, the iodine in the positive electrode material forms an iodine / iodine ion redox pair, and energy is stored by deposition / dissolution (solid / liquid). It has the advantages of high specific capacity, fast charge and discharge speed, good environmental protection, good cycle stability, and suitable potential range. It can be used as a high-performance positive electrode material for secondary seawater batteries.

[0017] The present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, and the selection of specific methods and conditions, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. New use of iodine as a positive electrode material for rechargeable and dischargeable seawater batteries.

2. The new use according to claim 1, characterized in that: In the positive electrode material, iodine is the only positive electrode active component.

3. The new use according to claim 1, characterized in that: With natural seawater as electrolyte, in the rechargeable and dischargeable seawater battery positive electrode material, the iodine forms an iodine / iodine ion redox pair to store energy through deposition / dissolution.

4. A rechargeable and dischargeable seawater battery positive electrode material, characterized in that: Contains elemental iodine.

5. The rechargeable and dischargeable seawater battery positive electrode material according to claim 4, characterized in that: Iodine is the only active ingredient in the positive electrode.

6. A rechargeable seawater battery, characterized in that: The positive electrode material as claimed in claim 4 or 5 is used.

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