Magnesium metal organic primary battery system and method for preparing button / pouch cell thereof

Abstract

The application relates to the technical field of button / soft package battery preparation, and discloses a magnesium metal organic primary battery system and a button / soft package battery preparation method thereof, which comprises a magnesium metal negative electrode, an organic electrolyte, a diaphragm and a positive electrode; the positive electrode comprises a positive electrode active material, a conductive agent and a binder; the positive electrode active material is carbon fluoride; and the organic electrolyte is formed by dissolving magnesium salt in an organic solvent. The magnesium metal negative electrode is not prone to generating dendrites in an electrochemical process, the crust abundance of raw materials is high, the price is low, and the market price is much lower than that of lithium metal. In addition, the magnesium metal is more stable in air than lithium, is relatively easier and safer to process and handle, still needs to be assembled into a battery under an inert atmosphere, but the requirement is not as harsh as that of lithium, which not only reduces the material cost, but also reduces the harsh requirement on the production environment, so that the manufacturing cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of button / pouch battery manufacturing technology, specifically to a magnesium metal organic primary battery system and its button / pouch battery manufacturing method. Background Technology

[0002] With the rapid development of portable electronic devices, IoT terminals, and special equipment such as aerospace, deep-sea, and military equipment, higher requirements are being placed on the energy density, safety, cost, and environmental adaptability of primary batteries. Currently, commercially available lithium primary batteries, such as lithium / manganese dioxide and lithium / thionyl chloride batteries, have high energy densities, but their inherent safety issues and high costs are becoming increasingly prominent, specifically in the following aspects:

[0003] (1) Commercial lithium primary batteries such as lithium / manganese dioxide and lithium / thionyl chloride batteries have high energy density, but lithium resources are limited, market prices are high, and chemical activity is high, which increases manufacturing costs; (2) Lithium metal anodes are prone to dendrite formation, which can easily puncture the separator during use, leading to the risk of internal short circuit and thermal runaway. Summary of the Invention

[0004] The purpose of this invention is to provide a magnesium metal organic primary battery system and a method for preparing coin / pouch batteries therewith, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a magnesium metal organic primary battery system and a method for preparing its coin / pouch battery, comprising a magnesium metal negative electrode, an organic electrolyte, a separator, and a positive electrode, characterized in that: the positive electrode comprises a positive electrode active material, a conductive agent, and a binder, wherein the positive electrode active material is a fluorinated carbon or manganese dioxide positive electrode material, and the organic electrolyte is composed of magnesium salt dissolved in an organic solvent.

[0006] Preferably, the magnesium metal negative electrode is made of magnesium alloy foil.

[0007] A method for manufacturing a button cell / pouch cell includes the following steps:

[0008] Step 1: Preparation of positive electrode sheet for button cell: Mix fluorinated carbon, conductive agent and binder in a mass ratio of 60%-95%:5%-30%:2%-10%, add N-methylpyrrolidone solvent to make a slurry, coat it evenly on the current collector, and after drying and rolling, cut it into small round sheets.

[0009] Step 2: Battery assembly: In the glove box, combine the negative electrode shell, magnesium sheet, separator, electrolyte, positive electrode plate, gasket, and spring with the positive electrode shell in sequence, and seal with a sealing machine;

[0010] Step 3: Preparation of positive and negative electrode sheets for pouch cells: The preparation method of the positive electrode sheet is the same as that of the coin cell, and the negative electrode uses magnesium foil. Both are cut into the required size.

[0011] Step 4: Stacking and welding: Stack the positive electrode, separator, negative electrode, and separator in sequence to form a multi-layer structure, and weld the aluminum / nickel tabs to the positive and negative current collectors respectively;

[0012] Step 5: Bagging and sealing: Place the stacked core package into the recess of the aluminum-plastic film and heat seal the three sides except for the air vent;

[0013] Step Six: Electrolyte Injection and Final Sealing: Electrolyte is injected through the gas port, and after being allowed to stand under vacuum for impregnation, a vacuum is drawn and the mixture is finally sealed.

[0014] Preferably, in step one, the positive electrode sheet is coated with slurry evenly onto the current collector using a coating machine, and the wet film thickness is controlled between 100-500 μm.

[0015] Preferably, in step one, the drying process involves pre-drying at 80°C for 10 minutes to remove most of the solvent, followed by vacuum drying at 120°C for 12 hours to completely remove residual solvent and moisture.

[0016] Preferably, in step one, the electrode sheet is punched using a circular die, and the diameter is determined according to the CR2032 standard button cell specifications.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. This invention utilizes magnesium metal, which is abundant in the Earth's crust, inexpensive, and has a market price far lower than that of lithium metal. Magnesium metal is more stable in air than lithium, and its processing and handling are relatively easier and safer. Although battery assembly still requires an inert atmosphere, the requirements are not as stringent as for lithium. This not only reduces material costs but also lowers the stringent requirements for the production environment, thereby significantly reducing manufacturing costs.

[0019] 2. This invention eliminates the risk of internal short circuits and thermal runaway caused by dendrites piercing the separator by preventing dendrite growth in the magnesium metal anode during deposition / dissolution, thus giving the battery extremely high intrinsic safety. Furthermore, magnesium, being a divalent metal, possesses extremely high theoretical volumetric capacity. Matching this with a high-energy-density fluorinated carbon cathode results in a battery system with high energy density, suitable for applications requiring both high energy density and high safety. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the exploded structure of the button cell of the present invention;

[0021] Figure 2 This is a schematic diagram of the soft-pack battery and its packaging structure according to the present invention;

[0022] Figure 3 The images show the XRD and SEM images of the fluorinated carbon cathode material of this invention.

[0023] Figure 4 The figures show the electrochemical discharge curves of the fluorinated carbon cathode material of this invention under different electrolyte systems.

[0024] Figure 5 This is a schematic diagram of the magnesium primary battery pouch cell of the present invention;

[0025] Figure 6 This is a graph showing the electrochemical performance of the magnesium primary battery pouch cell of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1:

[0028] Please see Figures 1-6 Magnesium metal organic primary battery system and its button / pouch battery preparation method, including magnesium metal negative electrode, organic electrolyte, separator and positive electrode, wherein the positive electrode includes positive electrode active material, conductive agent and binder, the positive electrode active material is fluorinated carbon or manganese dioxide positive electrode material, and the organic electrolyte is composed of magnesium salt dissolved in organic solvent.

[0029] In this embodiment, the magnesium metal negative electrode is made of magnesium metal foil.

[0030] A method for preparing a magnesium metal organic primary battery coin cell / soft pack battery includes the following steps: Step 1: Preparation of positive electrode sheet for coin cell battery: Fluorinated carbon, conductive agent, and binder are mixed in a mass ratio of 60%-95%:5%-30%:2%-10%, and N-methylpyrrolidone solvent is added to form a slurry. The slurry is uniformly coated on aluminum foil, dried, rolled, and then punched into small round pieces. Fluorinated carbon, conductive agent, and binder raw materials are prepared. The mixture is then stirred evenly, and the slurry is uniformly coated on the aluminum foil current collector using an automatic coating machine. The wet film thickness is controlled at 100-500μm. The coated slurry is then dried by pre-drying at 80℃ for 10 minutes to remove most of the solvent, and then vacuum-dried at 120℃ for 12 hours to completely remove residual solvent and moisture. The electrode sheet is then punched using a circular die, with the diameter determined according to the CR2032 standard coin cell battery specifications. Finally, the electrode sheet is dried a second time under vacuum conditions and quickly transferred to an argon-protected glove box for later use.

[0031] Step 2: Battery assembly: In the glove box, assemble the negative electrode shell, magnesium sheet, separator, electrolyte, positive electrode plate, gasket, spring, and positive electrode shell in sequence, and then seal them with a sealing machine.

[0032] Step 3: Preparation of positive and negative electrode sheets for pouch batteries: The preparation method of the positive electrode sheet is the same as that of the button cell battery. The negative electrode uses magnesium foil. Both are cut into the required size. The staff prepares the positive electrode sheet of the pouch battery, then prepares the negative electrode material magnesium foil, and then uses a mold to punch and cut the positive and negative electrode sheets.

[0033] Step 4: Stacking and Welding: Stack the positive electrode, separator, negative electrode, and separator in sequence to form a multi-layer structure, and weld the aluminum tabs to the positive and negative current collectors respectively. In the glove box, stack the positive electrode, separator, negative electrode, and separator in sequence to form a multi-layer structure. Then, use a glass fiber separator with a diameter slightly larger than the electrode sheet to ensure complete isolation between the positive and negative electrodes, and then seal it with a sealing machine.

[0034] Step 5: Bagging and Sealing: Place the stacked core package into the recess of the aluminum-plastic film, and heat seal the three sides except for the air vent. The staff put the stacked core package into the recess of the aluminum-plastic film, and then use the heat sealing machine to heat seal the three sides except for the air vent. Then, the edges after heat sealing are cooled for inspection. Finally, the sealing quality is strictly inspected to ensure that there is no leakage and no deformation.

[0035] Step Six: Electrolyte Injection and Final Sealing: Inject electrolyte through the vent, allow it to stand under vacuum and then seal it. Then, inject precisely measured amounts of electrolyte through the vent. The amount of electrolyte injected is calculated based on the electrode capacity. After sealing, the battery needs to stand for 24 hours to allow the electrolyte to fully wet the electrodes and separator.

[0036] In this embodiment: in step one, the carbon paper foil is coated with an automatic coating machine to uniformly coat the slurry onto the aluminum foil current collector, and the wet film thickness is controlled between 100-500μm.

[0037] In this embodiment: in step one, the drying process involves pre-drying at 80°C for 10 minutes to remove most of the solvent, followed by vacuum drying at 120°C for 12 hours to completely remove residual solvent and moisture.

[0038] In this embodiment: In step one, the electrode sheet is punched using a circular die, and the diameter is determined according to the CR2032 standard button cell specifications.

[0039] In this embodiment: the electrode is dried twice under vacuum at 120°C for 4 hours and then quickly transferred to an argon-protected glove box for later use.

[0040] Example 2:

[0041] As shown in the figure, unlike Example 1, the preparation method of a magnesium metal-organic primary battery pouch cell in this example includes the following steps:

[0042] S1. Electrode Preparation: The positive and negative electrode materials, conductive agent, and binder are mixed in proportion to form a uniform slurry. The slurry is then coated onto aluminum foil (positive electrode) or copper foil (negative electrode) and dried to form an electrode sheet. The electrode sheet is then compacted using a roller press to improve energy density and conductivity. The electrode sheet is then cut into strips and punched into the designed shape, with pre-reserved positions for electrode tab welding.

[0043] S2. Cell assembly: Stack the cells in the order of "positive electrode + separator + negative electrode" to form a cell; use an ultrasonic welding machine to weld the tabs to the current collector.

[0044] S3. Packaging and electrolyte injection: The hole is punched to form a "Pocket" to store the battery cell. Then, the aluminum-plastic film is heated in the top sealing and side sealing machine, leaving a seal for electrolyte injection. Electrolyte is injected through the seal and then the seal is closed.

[0045] S4. Formation and Testing: Allow the electrolyte to fully wet the electrode, then activate the battery by charging with a small current, and then test the capacity using a battery analyzer.

[0046] In summary, both Embodiment 1 and Embodiment 2 utilize magnesium, a raw material with high crustal abundance and low price, whose market price is far lower than that of lithium metal. Magnesium is more stable in air than lithium, and its processing and handling are relatively easier and safer. Although battery assembly still requires an inert atmosphere, the requirements are less stringent than for lithium. This not only reduces material costs but also lowers the stringent requirements for the production environment, thereby significantly reducing manufacturing costs.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A magnesium metal organic primary battery system, comprising a magnesium metal negative electrode, an organic electrolyte, a separator, and a positive electrode, characterized in that: The positive electrode includes a positive electrode active material, a conductive agent, and a binder. The positive electrode active material is a fluorinated carbon or manganese dioxide positive electrode material, and the organic electrolyte is composed of magnesium salt dissolved in an organic solvent.

2. The magnesium metal organic primary battery system according to claim 1, characterized in that: The magnesium metal anode is made of magnesium metal / magnesium alloy foil.

3. A method for preparing a button / pouch battery, based on the magnesium metal-organic primary battery system according to any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Preparation of positive electrode sheet for button cell: Mix fluorinated carbon, conductive agent and binder in a mass ratio of 60%-95%:5%-30%:2%-10%, add N-methylpyrrolidone solvent to make a slurry, coat it evenly on the current collector, and after drying, cut it into small round sheets. Step 2: Battery assembly: In the glove box, combine the negative electrode shell, magnesium sheet, separator, electrolyte, positive electrode plate, gasket, and spring with the positive electrode shell in sequence, and seal with a sealing machine; Step 3: Preparation of positive and negative electrode sheets for pouch cells: The preparation method of the positive electrode sheet is the same as that of the coin cell, and the negative electrode uses magnesium foil. Both are cut into the required size. Step 4: Stacking and welding: Stack the positive electrode, separator, negative electrode, and separator in sequence to form a multi-layer structure, and weld the aluminum / nickel tabs to the positive and negative current collectors respectively; Step 5: Bagging and sealing: Place the stacked core package into the recess of the aluminum-plastic film and heat seal the three sides except for the air vent; Step Six: Electrolyte Injection and Final Sealing: Electrolyte is injected through the gas port, and after being allowed to stand under vacuum for impregnation, a vacuum is drawn and the mixture is finally sealed.

4. The method for manufacturing a button / pouch battery according to claim 3, characterized in that: In step one, the aluminum foil is coated using a coating machine to evenly coat the slurry onto the current collector, with the wet film thickness controlled between 100-500 μm.

5. The method for manufacturing a button / pouch battery according to claim 3, characterized in that: In step one, the drying process involves pre-drying at 80°C for 10 minutes to remove most of the solvent, followed by vacuum drying at 120°C for 12 hours to completely remove any residual solvent.

6. The method for manufacturing a button / pouch battery according to claim 3, characterized in that: In step one, the electrode sheet is punched using a circular die, and the diameter is determined according to the CR2032 standard button cell specifications.

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