Battery pouch simulation device and battery testing method based thereon

Abstract

The application relates to the technical field of batteries, in particular to a battery soft package simulation device and a battery test method based on the same. The device comprises an upper pressing plate and a lower base. The upper pressing plate is provided with an upper fixing part and a clamping groove. The lower base is provided with a containing groove, a lower fixing part corresponding to the upper fixing part, and a boss matched with the clamping groove. The boss forms a tab passage on both sides. During testing, the cut positive electrode sheet, the diaphragm and the negative electrode sheet are sequentially placed in the containing groove. After the electrolyte is injected, the upper pressing plate is buckled and fixed. The tabs are connected with the charging and discharging device through the tab passage. The actual stress state of the battery can be simulated, and tests such as charging and discharging, cycle life and impedance spectrum can be carried out. The device improves the reliability and repeatability of test data and reduces experimental cost.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery pouch simulation device and a battery testing method based thereon. Background Technology

[0002] Existing battery testing methods commonly employ coin cells and pouch cells. Coin cells are widely used due to their simple structure and ease of operation, but they have significant limitations. First, the electrode area of ​​coin cells is small, making them highly susceptible to assembly errors and contact resistance, resulting in highly volatile test data that fails to accurately reflect the overall electrochemical performance of the material. Second, the encapsulation method of coin cells restricts electrolyte wettability, easily leading to uneven electrode reactions and affecting the reliability of test results.

[0003] In contrast, pouch cells are closer to real-world applications, featuring larger electrode areas and better electrolyte wettability, effectively reducing localized current density variations and resulting in more stable test data. However, the assembly process of pouch cells is complex and requires sophisticated equipment, typically necessitating specialized pouch packaging equipment and precise environmental control conditions, which limits their widespread use in ordinary laboratories.

[0004] In the research of sodium-free anode batteries, the stability of the SEI solid electrolyte interface layer and the suppression of sodium dendrites are key influencing factors. Traditional coin cells are prone to SEI solid electrolyte interface layer rupture and reconstruction during long-term charge-discharge cycles due to small electrode area and uneven pressure, which in turn leads to sodium dendrite growth and affects battery performance. While pouch cells can partially solve this problem, their high cost and complex manufacturing process remain obstacles to laboratory research. Summary of the Invention

[0005] To address the technical problems of coin cells being easily damaged by long-term cyclic charging and discharging in existing battery testing technologies, and pouch cells being costly and complex to manufacture, this invention provides a pouch battery simulation device and a battery testing method based thereon.

[0006] Therefore, the present invention provides the following technical solution:

[0007] A battery pouch simulation device includes an upper pressure plate and a lower base. The upper pressure plate extends outward along all edges except one side to form an upper fixing part. A slot is provided downward at the unextended edge of the upper pressure plate. The lower base has a receiving groove corresponding to the shape of the upper pressure plate. A lower fixing part is provided at all edges except one side of the outer edge of the receiving groove, and the lower fixing part corresponds to the upper fixing part of the upper pressure plate. A boss is provided at the edge of the receiving groove where the lower fixing part is not provided, and the boss is adapted to the slot of the upper pressure plate. There is a gap between the two sides of the boss and its corresponding two side edges to form a tab channel.

[0008] Furthermore, the upper pressure plate is rectangular in shape, and the upper fixing part is located at a pair of long sides and a short side of the upper pressure plate.

[0009] Furthermore, corresponding positions on the upper and lower fixing parts are provided with threaded fixing holes for mounting bolts to fix the upper pressure plate and the lower base together.

[0010] A battery testing method based on the aforementioned battery pouch simulation device includes the following steps:

[0011] Sodium source, transition metal oxide and carbonate are mixed and ground according to chemical formula;

[0012] The powder obtained by grinding is sintered in an oxygen atmosphere, an argon atmosphere, or a nitrogen atmosphere.

[0013] The active material obtained by sintering is mixed with electronic conductive material and binder and ground. Then, solvent is added, the mixture is stirred and coated on current collector to obtain positive electrode sheet.

[0014] The positive electrode sheet is dried in a vacuum environment and then cut according to the shape of the receiving groove;

[0015] Cut the diaphragm and negative electrode according to the shape of the positive electrode;

[0016] Then, place the cut positive electrode, separator and negative electrode into the receiving tank in sequence, add electrolyte into the receiving tank, put the upper pressure plate into the receiving tank and fix the upper pressure plate to the lower base;

[0017] The positive tab of the positive electrode and the negative tab of the negative electrode are passed through the tab channel and connected to the charging and discharging device respectively for charging and discharging testing.

[0018] Furthermore, the sodium source is sodium carbonate or sodium hydroxide; the transition metal oxide is manganese oxide, nickel oxide, copper oxide, zirconium oxide, or molybdenum oxide; and the carbonate is manganese carbonate or nickel carbonate.

[0019] Furthermore, the temperature during the sintering process is 700-950℃, and the time is 6-12h.

[0020] Furthermore, during the mixing process of the active material with the electronically conductive material and the binder, the proportion of the active material is between 70% and 95%, the proportion of the electronically conductive material is between 5% and 15%, and the proportion of the binder is between 5% and 15%.

[0021] Furthermore, the electronically conductive material is selected from at least one of furnace black, acetylene black, Ketjen black, carbon fiber, carbon nanotubes, carbon nanowires, graphene, and conductive graphite sheets; the solvent is selected from at least one of dimethylformamide, dimethyl sulfoxide, sulfolane, ethyl nitrate, and N-methylpyrrolidone; and the binder is selected from at least one of polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, styrene-butadiene rubber, nitrile rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, and polymethyl methacrylate.

[0022] Furthermore, the electrolyte is one or more of an electrolyte or a solid electrolyte; wherein the solid electrolyte is at least one selected from oxide electrolytes, sulfide electrolytes, and polymer electrolytes.

[0023] Furthermore, the diaphragm is selected from at least one of PP diaphragm, PE diaphragm, non-woven fabric diaphragm, glass fiber diaphragm, PTFE diaphragm, and PVDF diaphragm.

[0024] Advantages and positive effects of the present invention:

[0025] The upper pressure plate and lower base simulate the pouch cell of a soft-pack battery. Based on the shape of the receiving groove on the lower base, corresponding electrodes and separators are produced. The positive electrode, separator, and negative electrode are sequentially placed into the receiving groove, the upper pressure plate is closed, electrolyte is injected, and the positive tab of the positive electrode and the negative tab of the negative electrode are passed through the tab channels of the receiving groove and connected to a charge-discharge device for charge-discharge testing. This soft-pack simulation device can simulate the stress state of the battery under actual use conditions, perform standard charge-discharge tests, cycle life tests, and electrochemical impedance spectroscopy analysis to evaluate material performance and SEI film stability. Test results show that this device effectively improves the reliability and repeatability of test data, is not easily damaged by long-term cycle charge-discharge, and has low cost, simple process, reduced experimental costs, and improved experimental efficiency. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a structural diagram of a battery pouch simulation device provided by the present invention.

[0028] Figure 2 This is a bottom view of the pressure plate of a battery pouch simulation device provided by the present invention.

[0029] Figure 3 This is a front view of the upper pressure plate of a battery pouch simulation device provided by the present invention.

[0030] Figure 4 This is a top view of the lower base of a battery pouch simulation device provided by the present invention.

[0031] Figure 5 This is a front view of the lower base of a battery pouch simulation device provided by the present invention.

[0032] Figure 6 The potential-specific capacity curve is obtained by a battery testing method based on a battery soft-pack simulation device provided by the present invention.

[0033] In the diagram: 1. Upper pressure plate; 2. Lower base; 3. Upper fixing part; 4. Slot; 5. Receiving slot; 6. Lower fixing part; 7. Boss; 8. Electrode channel; 9. Threaded fixing hole. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0035] This invention provides a battery pouch simulation device and a battery testing method based thereon, wherein the battery pouch simulation device, such as... Figure 1-5 As shown, it includes an upper pressure plate 1 and a lower base 2. The upper pressure plate 1 extends outward along all edges except one side to form an upper fixing part 3. The upper pressure plate 1 has a slot 4 at the unextended edge. The lower base 2 has a receiving groove 5 corresponding to the shape of the upper pressure plate 1. In the outer edge of the receiving groove 5, except one side, the other edges are provided with lower fixing parts 6, and the lower fixing parts 6 correspond to the upper fixing parts 3 of the upper pressure plate 1. The edge of the receiving groove 5 where the lower fixing parts 6 are not provided has a boss 7, and the boss 7 is adapted to the slot 4 of the upper pressure plate 1. There is a gap between the two sides of the boss 7 and its corresponding two side edges to form an electrode ear channel 8.

[0036] The upper pressure plate 1 is specifically rectangular in shape, and the upper fixing part 3 is located at a pair of long sides and a short side of the upper pressure plate 1. The upper fixing part 3 and the lower fixing part 6 are provided with threaded fixing holes 9 at corresponding positions for mounting bolts to fix the upper pressure plate 1 and the lower base 2 together.

[0037] A battery testing method based on a battery pouch simulation device includes the following steps:

[0038] Sodium source, transition metal oxide and carbonate are prepared and ground according to chemical formula; sodium source is sodium carbonate or sodium hydroxide; transition metal oxide is manganese oxide, nickel oxide, copper oxide, zirconium oxide or molybdenum oxide; carbonate is manganese carbonate or nickel carbonate.

[0039] The powder obtained from grinding is sintered in an oxygen atmosphere, an argon atmosphere, or a nitrogen atmosphere; the temperature during the sintering process is 700-950℃, and the time is 6-12h.

[0040] The sintered active material is mixed with an electronically conductive material and a binder, then ground. A solvent is added, the mixture is homogenized, and coated onto a current collector to obtain a positive electrode sheet. During the mixing process, the proportion of the active material, electronically conductive material, and binder is between 70% and 95%, the proportion of the electronically conductive material is between 5% and 15%, and the proportion of the binder is between 5% and 15%. The electronically conductive material is selected from at least one of furnace black, acetylene black, Ketjen black, carbon fiber, carbon nanotubes, carbon nanowires, graphene, and conductive graphite sheets. The solvent is selected from at least one of dimethylformamide, dimethyl sulfoxide, sulfolane, ethyl nitrate, and N-methylpyrrolidone. The binder is selected from at least one of polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, styrene-butadiene rubber, nitrile rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, and polymethyl methacrylate. The coating thickness is between 50 micrometers and 500 micrometers.

[0041] Place the positive electrode sheet in a vacuum oven and dry it in a vacuum environment. The temperature in the vacuum oven is 80℃-120℃ and the drying time is 12 hours. After drying, collect the electrode sheet and cut it according to the shape of the receiving groove 5. The standard size is 50mm in length and 50mm in width, with a 10mm wide and 30mm long section left as the electrode tab.

[0042] The separator and negative electrode are cut according to the shape of the positive electrode. The separator is selected from at least one of PP separator, PE separator, non-woven separator, glass fiber separator, PTFE separator, and PVDF separator.

[0043] The cut positive electrode, separator, and negative electrode are then placed into the receiving tank 5 in sequence. After adding electrolyte into the receiving tank 5, the upper pressure plate 1 is inserted into the receiving tank 5 and fixed to the lower base 2. The electrolyte is one or more of an electrolyte or a solid electrolyte. The solid electrolyte is at least one selected from oxide electrolytes, sulfide electrolytes, and polymer electrolytes.

[0044] The positive tab of the positive electrode and the negative tab of the negative electrode are passed through the tab channel 8 and connected to the charging and discharging device respectively for charging and discharging testing.

[0045] Example:

[0046] Prepare the required sodium carbonate, manganese carbonate, nickel carbonate, and copper oxide according to... The chemical formula was used to prepare the ingredients, which were then placed in a 500 ml ball mill jar and ball-milled at 500 r per minute for 2 hours to obtain a uniform powder.

[0047] The powder was placed in an alumina ceramic boat and placed in a tube furnace. The temperature was increased to 950°C at a rate of 5°C / min and held at that temperature for 12 hours in an oxygen atmosphere. Then, the furnace was cooled to room temperature to obtain the sintered cathode material.

[0048] The sintered powder is ground to break up large particles, resulting in uniform powder with a particle size of 5-10 micrometers, which is then set aside.

[0049] Weigh the positive electrode material powder, conductive agent acetylene black, and binder PVDF in a mass ratio of 75%:10%:15% and set aside.

[0050] The cathode material powder and acetylene black were thoroughly mixed, PVDF was added, and the mixture was continued to be mixed evenly to obtain the mixture.

[0051] Add NMP to the resulting mixture and stir until homogeneous to form a slurry.

[0052] The slurry is uniformly coated onto the aluminum foil current collector, with the coating thickness controlled between 50-500 micrometers. After coating, it is placed in a vacuum oven at 120℃ and dried for 12 hours. After drying, it is rolled using a roller press to increase the electrode density.

[0053] The dried electrode sheets are cut into positive electrode sheets that meet the size requirements of the soft-pack simulation device and set aside for later use.

[0054] Commercial sodium metal sheets or carbon-based materials are used as negative electrode materials and cut to the size that matches the positive electrode sheet.

[0055] Inside the glove box, stack the positive electrode, separator, and negative electrode neatly in sequence, ensuring that each layer of material is aligned.

[0056] The stacked electrode structure is placed inside the soft-pack simulation device, and the upper pressure plate is locked to the lower base with bolts to ensure good interlayer contact.

[0057] Electrolyte is injected through the tab channel, and negative pressure operation is used to ensure that the electrolyte fully wets the electrode plate.

[0058] Adjust the bolts to achieve the required pressure environment inside the device, simulating the stress conditions under actual battery operation.

[0059] Check the airtightness of the device and proceed with subsequent tests after confirming there are no leaks.

[0060] Connect the tabs that pass through the tab channel of the soft-pack simulation device to the charge-discharge battery testing system, and conduct standard charge-discharge tests at 0.1C, 0.5C, and 1C rates, recording key parameters such as the first charge-discharge capacity and coulombic efficiency.

[0061] The constant current-constant voltage charging mode is used to charge the battery to 4.0V, then constant voltage charging until the current decays to one-tenth of the initial current, and then discharges it to 2.0V under 0.1C conditions.

[0062] The battery capacity retention rate and coulombic efficiency were observed through cyclic charge-discharge tests.

[0063] By comparing the performance differences of batteries under different pressure conditions, the simulation accuracy of the pouch cell simulator for battery material properties was evaluated. Electrochemical impedance spectroscopy (EIS) was used to perform interfacial impedance analysis on the assembled battery to further confirm the stability of the SEI film formation. The reliability and application prospects of the pouch cell simulator in sodium-free anode battery research were analyzed based on the above test data.

[0064] like Figure 6 As shown, the first two charge-discharge potential and specific capacity curves of a battery assembled with a cathode material and hard carbon were obtained using a pouch-pack simulator. During the experiment, the average operating voltage remained above 3.1 V, and the energy density exceeded 200 Wh / kg, demonstrating a high output voltage plateau and good energy release capability, laying a solid foundation for subsequent performance optimization and long-cycle testing. These results validate the effectiveness and practical value of the pouch-pack simulator in simulating real-world battery service conditions. The electrochemical curves are complete and have normal morphology; the charge-discharge curves are continuous without interruptions or abnormal jumps; and the voltage changes smoothly with capacity, indicating good device connection and controllable electrode reactions. The curves exhibit distinct charge-discharge characteristics, with clear plateaus or slopes, indicating that the electrode material participates in reversible reactions.

[0065] The ability to complete two full charge-discharge cycles with continuous data indicates that the device has no problems in terms of pressure application, sealing, and electrical contact, and can be used as a test platform for subsequent material screening or evaluation of new structures.

[0066] The initial charge / discharge capacity and voltage range is 1.6V–4.0V, which meets the testing specifications for most sodium-ion or lithium-ion battery materials.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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; and these 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.

Claims

1. A battery test method based on a battery soft pack simulation device, characterized in that, The battery soft package simulation device comprises an upper pressing plate (1) and a lower base (2), the upper pressing plate (1) is extended outward along the periphery of the upper pressing plate (1) except one edge to form an upper fixing part (3), and the upper pressing plate (1) is provided with a clamping groove (4) downward at the edge not extended; the lower base (2) is provided with a receiving groove (5) corresponding to the shape of the upper pressing plate (1), and the lower fixing part (6) is arranged at the remaining edges except one edge of the periphery edge of the receiving groove (5), and the lower fixing part (6) is corresponding to the position of the upper fixing part (3) of the upper pressing plate (1), the edge of the receiving groove (5) not provided with the lower fixing part (6) is provided with a boss (7) corresponding to the clamping groove (4) of the upper pressing plate (1), and the boss (7) is adapted to the clamping groove (4) of the upper pressing plate (1), and the boss (7) is provided with a tab passage (8) between the two sides of the boss (7) and the corresponding two side edges. The battery test method comprises the following steps: The sodium source, transition metal oxide and carbonate are dosed according to the chemical formula and ground; The ground powder is sintered in an oxygen atmosphere, an argon atmosphere or a nitrogen atmosphere; The active material obtained by sintering is mixed with electronic conductive material and adhesive and ground, then a solvent is added and mixed to coat on the current collector to obtain a positive electrode tab; The positive electrode tab is dried in a vacuum environment and cut according to the shape of the receiving groove (5); The separator and the negative electrode tab are cut according to the shape of the positive electrode tab; The cut positive electrode tab, separator and negative electrode tab are sequentially placed in the receiving groove (5), electrolyte is added into the receiving groove (5), the upper pressing plate (1) is buckled into the receiving groove (5), and the upper pressing plate (1) and the lower base (2) are fixed; The positive tab of the positive electrode tab and the negative tab of the negative electrode tab are passed through the tab passage (8) and connected with the charge-discharge device respectively for charge-discharge test.

2. The battery testing method based on a battery pouch simulation device according to claim 1, wherein The sodium source is sodium carbonate or sodium hydroxide; the transition metal oxide is manganese oxide, nickel oxide, copper oxide, zirconium oxide or molybdenum oxide; and the carbonate is manganese carbonate or nickel carbonate.

3. The battery testing method based on a battery pouch simulation device of claim 1, wherein, The temperature in the sintering process is 700-950 DEG C, and the time is 6-12 h.

4. The battery testing method based on a battery pouch simulation device of claim 1, wherein, In the mixing process of the active material, electronic conductive material and adhesive, the proportion of the active material is 70%-95%, the proportion of the electronic conductive material is 5%-15%, and the proportion of the adhesive is 5%-15%.

5. The battery testing method based on a battery pouch simulation device of claim 1, wherein, The electronic conductive material is at least one selected from furnace black, acetylene black, ketjen black, carbon fiber, carbon nanotube, carbon nanowire, graphene and conductive graphite sheet; the solvent is at least one selected from dimethylformamide, dimethyl sulfoxide, sulfolane, ethylene nitrate and N-methyl pyrrolidone; and the adhesive is at least one selected from polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, butadiene rubber, butyronitrile rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile and polymethyl methacrylate.

6. The battery testing method based on a battery pouch simulation device of claim 1, wherein, The electrolyte is one or more than one selected from electrolyte and solid-state electrolyte; and the solid-state electrolyte is at least one selected from oxide electrolyte, sulfide electrolyte and polymer electrolyte.

7. The battery testing method based on a battery pouch simulation device of claim 1, wherein, The diaphragm is at least one selected from PP diaphragm, PE diaphragm, non-woven fabric diaphragm, glass fiber diaphragm, PTFE diaphragm, PVDF diaphragm.

8. The battery testing method based on a battery pouch simulation device of claim 1, wherein, The upper pressing plate (1) is in the shape of a cuboid, and the upper fixing part (3) is located at a pair of long edges and one short edge of the upper pressing plate (1).

9. The battery testing method based on a battery pouch simulation device of claim 1, wherein, Corresponding positions on the upper fixing part (3) and the lower fixing part (6) are provided with threaded fixing holes (9) for mounting bolts to fix the upper pressing plate (1) and the lower base (2) together.

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