Aqueous battery manufacturing method and aqueous battery system

Abstract

The present invention belongs to the technical field of green energy application, and discloses a method and system for manufacturing an aqueous battery, the method comprising the following steps: selecting nickel phosphide as the positive electrode of the battery, sodium titanium phosphate as the negative electrode of the battery, selecting an inorganic salt combined with an organic salt solution as the electrolyte, wherein the molar ratio of the inorganic salt to the organic salt is 19:2; controlling the negative electrode / positive electrode unit area capacity ratio to be between 1.2-1.5 for packaging testing. The present invention also provides a system for manufacturing an aqueous battery manufactured by the above method. The battery manufactured by the present invention has a high theoretical energy density (full battery energy density>70Whkg-1), a stable and safe process, and is environmentally friendly throughout its life cycle, meets the requirements of energy conservation and emission reduction, and is suitable for promotion and application in the large-scale energy storage market of microgrids.

Description

Technical Field

[0001] The present invention belongs to the technical field of green energy application, and specifically discloses a dual-ion aqueous battery system suitable for large-scale power grid energy storage applications. Background Art

[0002] The development and effective use of renewable energy has become an important part of the energy development strategy of countries around the world. It is also a hot area that the industry pays close attention to and focuses on overcoming a number of technical and equipment problems. It is also a scientific issue that the academic community focuses on, and is committed to seizing the academic frontier and leading the strategic commanding heights of future energy sustainable development. In order to reduce carbon emissions, ensure energy security and promote sustainable development, countries around the world have begun to formulate energy structure transformation strategies in the post-fossil energy era, and the proportion of renewable energy power generation has been gradually increased. By the end of 2020, my country's installed capacity of renewable energy power generation reached 934 million kilowatts, a year-on-year increase of about 17.5%, and the country's renewable energy power generation reached 221.48 billion kilowatt-hours, a year-on-year increase of about 8.4%.

[0003] In response to this, large-scale energy storage technology came into being, which can realize the integration of internal power supply loads, efficiently store and convert electrical energy, effectively respond to the increasing demand for electricity, and realize the spatiotemporal regulation of electrical energy. There are many energy storage technologies suitable for microgrids, and their performance effects have their own advantages. Combining the development characteristics of microgrids and market demand, battery energy storage will be the mainstream direction of future development. However, the energy density and efficiency of lead-acid batteries manufactured by existing methods on the market are too low, and they contain heavy metals, which can easily cause environmental pollution if not properly recycled; lithium battery electrode materials are expensive and have poor safety, which limits the possibility of large-scale promotion and makes it difficult to meet the market demand for large-scale energy storage in microgrids. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art in terms of monitoring data transmission and processing, the present invention provides a method for manufacturing an aqueous battery, comprising the following steps:

[0005] S1. Nickel phosphide is used as the positive electrode of the battery, sodium titanium phosphate is used as the negative electrode of the battery, the particle size of the positive and negative electrode materials is controlled within 200nm as much as possible, the carbon content is less than 2.5%, and the positive and negative electrode materials need to be hydrophilic treated to maintain a contact angle greater than 120°;

[0006] S2. Selecting an inorganic salt combined with an organic salt solution as the electrolyte, wherein the molar ratio of the inorganic salt to the organic salt is 19:2;

[0007] S3. Control the negative electrode / positive electrode unit area capacity ratio between 1.2-1.5 for packaging test.

[0008] Preferably, the inorganic salt is NaOH, and the organic salt is NaOTF.

[0009] Another embodiment of the present invention provides an aqueous battery system, comprising:

[0010] A positive electrode, a negative electrode, an electrolyte, and a diaphragm, wherein the lower parts of the positive electrode and the negative electrode are immersed in the electrolyte, and the diaphragm is placed in the electrolyte between the positive electrode and the negative electrode to separate the two poles of the battery. It is characterized in that the material of the positive electrode includes nickel phosphide, the material of the negative electrode includes sodium titanium phosphate, the electrolyte is a mixture of an inorganic salt solution and an organic salt solution in a molar ratio of 19:2, and the negative electrode / positive electrode unit area capacity ratio is controlled to be between 1.2 and 1.5 during packaging testing.

[0011] Preferably, the inorganic salt solution is NaOH, and the organic salt solution is NaOTF.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. Both the electrode materials and electrolytes are safe and low-cost electrode materials, and the materials used in the whole battery are basically existing industrial products;

[0014] 2. The present invention is a series of "aqueous battery" products, which are safer than lithium-ion batteries, lead-acid batteries, etc.;

[0015] 3. The present invention utilizes the mechanism of co-charging of anions and cations in the electrolyte to improve the overall energy density of the aqueous battery. Na+ and OH- participate in the reaction respectively, which promotes the utilization efficiency of ions in the electrolyte, thereby improving the overall energy density;

[0016] 4. The present invention finds that a NaOH-NaOTF electrolyte mixed in a molar ratio of 19:2 can assist in generating an effective SEI to inhibit the hydrogen evolution reaction of water molecules on the negative electrode surface, and can effectively improve the conductivity of the electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the water battery system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making innovative efforts are within the scope of protection of the present invention.

[0019] Nickel phosphide is used as the positive electrode of the battery, and sodium titanium phosphate is used as the negative electrode of the battery. The particle size of the positive and negative electrode materials is controlled within 200nm as much as possible, and the carbon content is less than 2.5%. The positive and negative electrode materials need to be hydrophilic to maintain a contact angle greater than 120°.

[0020] According to the Hofmeister sequence, the high solubility of ClO4- in water may be related to its easy participation in the solvation structure to break the aggregation structure of water molecules. Studies have shown that high-concentration NaOH electrolyte can effectively reduce the activity of water, but due to the high solubility of the reduction product of NaOH in water, an effective SEI cannot be formed. Therefore, the present invention adds 2m NaOTF of the same concentration to the saturated 19mNaOH to assist in the generation of an effective SEI to inhibit the hydrogen evolution reaction of water molecules on the negative electrode surface. The electrochemical stability window of the electrolyte is widened to 2.8V (1.6~4.4V). Based on the characteristics of inorganic electrolyte salts, the ionic conductivity of the electrolyte is as high as 95.25mS / cm-1, and the viscosity is only 12.3mPaS. According to the drawings in this application Figure 1 The packaging test was performed by controlling the negative electrode / positive electrode unit area capacity ratio between 1.2 and 1.5.

[0021] The specific charging electrochemical reaction mechanism is as follows:

[0022] Negative electrode: NaTi 2 (PO 4 ) 3 +xNa + +xe - →Na (1+x) Ti 2 (PO 4 ) 3

[0023] Positive electrode: Ni 2 P+xOH-→Ni 2 P(OH) x +xe -

[0024] The electrode materials and electrolyte components of this battery are basically low-cost industrial principles. Its large-scale production has low installation costs. Calculation and analysis show that its theoretical energy density is high (full battery energy density > 70Whkg-1). The process is stable and safe, and it is environmentally friendly throughout its life cycle, meeting the requirements of energy conservation and emission reduction.

[0025] The present invention optimizes the classic material sodium titanium phosphate and finds that polyacrylonitrile is used to carbon-coat the sodium titanium phosphate. After carbonization, polyacrylonitrile forms a rich pore structure that can effectively absorb sodium ions and significantly increase the conductivity of the negative electrode material (by about 5%).

[0026] The storage battery manufactured by the method provided in the above embodiment is an embodiment of an aqueous battery system.

[0027] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computers, available storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0028] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0029] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0030] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for manufacturing an aqueous battery, characterized in that The following steps are involved: S1. Nickel phosphide is used as the positive electrode of the battery, sodium titanium phosphate is used as the negative electrode of the battery, the particle size of the positive and negative electrode materials is controlled within 200nm, the carbon content is less than 2.5%, and the positive and negative electrode materials need to be hydrophilic treated to maintain a contact angle greater than 120°, and carbonized polyacrylonitrile is used to carbonize the sodium titanium phosphate; S2. Selecting an inorganic salt combined with an organic salt solution as the electrolyte, wherein the molar ratio of the inorganic salt to the organic salt is 19:2; S3. Control the negative electrode / positive electrode unit area capacity ratio between 1.2-1.5 for packaging test; The inorganic salt is NaOH, and the organic salt is NaOTF.

2. An aqueous battery system, comprising a positive electrode, a negative electrode, an electrolyte, and a diaphragm, wherein the lower parts of the positive electrode and the negative electrode are immersed in the electrolyte, and the diaphragm is placed in the electrolyte between the positive electrode and the negative electrode to separate the two electrodes of the battery, characterized in that: The material of the positive electrode includes nickel phosphide, and the material of the negative electrode includes sodium titanium phosphate. Carbonized polyacrylonitrile is used to carbon-wrap the sodium titanium phosphate. The electrolyte is a mixture of an inorganic salt solution and an organic salt solution in a molar ratio of 19:

2. During the packaging test, the negative electrode / positive electrode unit area capacity ratio is controlled to be between 1.2 and 1.

5. The inorganic salt solution is NaOH, and the organic salt solution is NaOTF.

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