Battery and method of manufacturing the same

Abstract

This invention relates to the field of battery technology, and particularly to a battery and its preparation method. The battery preparation method includes the following steps: providing a battery casing, wherein a battery cell is assembled inside the battery casing and filled with a preset gas, the preset gas contacting the surface of the battery cell and entering the internal pores of the battery cell; providing a first electrode, the first electrode being electrically connected to the positive or negative electrode of the battery cell; providing a second electrode, adjusting the position of the second electrode so that a portion of the preset gas is located within the discharge gap between the first and second electrodes; breaking down a portion of the preset gas to generate plasma, using the plasma to treat the battery cell; removing the first and second electrodes to prepare the battery. This invention can improve the problems of low electrolyte injection efficiency and poor wetting quality.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to batteries and their preparation methods. Background Technology

[0002] A battery is a device that converts chemical energy into electrical energy. It is formed by injecting electrolyte into a battery case containing battery cells. The electrolyte injection process is an important step in battery manufacturing.

[0003] The electrolyte injection process typically consists of two steps: dispensing and wetting. This process is usually time-consuming, and even with this time commitment, poor wetting quality of the battery cell by the electrolyte can still occur. When poor wetting occurs, it can be assumed that there are empty areas inside the battery cell lacking electrolyte, which hinders lithium-ion transport. This prevents some active materials or conductive agents from functioning properly, affecting the battery's electrochemical performance and potentially even causing lithium plating, thus compromising battery safety. Summary of the Invention

[0004] Based on this, the present invention provides a battery and its preparation method to improve the problems of low electrolyte injection efficiency and poor wetting quality.

[0005] The first aspect of this invention provides a battery, the technical solution of which is as follows:

[0006] A method for preparing a battery includes the following steps:

[0007] A battery casing is provided, wherein a battery cell is assembled inside the battery casing and filled with a preset gas, the preset gas contacting the surface of the battery cell and entering the internal pores of the battery cell;

[0008] A first electrode is provided, which is electrically connected to the positive or negative electrode of the battery cell;

[0009] A second electrode is provided, and the position of the second electrode is adjusted so that a portion of the preset gas is located within the discharge gap between the first electrode and the second electrode;

[0010] The preset gas is broken down to generate plasma, which is then used to process the battery cell.

[0011] Remove the first and second electrodes to prepare the battery.

[0012] In some embodiments, the second electrode is electrically connected to the negative or positive electrode of the battery cell.

[0013] In some embodiments, the second electrode is disposed on any surface of the battery cell and is not in contact with or is insulated from the surface of the battery cell.

[0014] In some embodiments, the second electrode is disposed on any surface of the battery casing and is not in contact with or is insulated from the surface of the battery casing.

[0015] In some embodiments, the second electrode is disposed on the positive or negative terminal of the battery casing and is either not in contact with or insulated from the positive or negative terminal.

[0016] In some embodiments, the battery cell is formed by lamination or winding.

[0017] In some embodiments, the battery cell has a hollow cavity, and the second electrode is disposed within the hollow cavity.

[0018] In some embodiments, the battery cell is formed by winding.

[0019] In some embodiments, the preset gas is selected from air, nitrogen, argon, oxygen, hydrogen, or combinations thereof.

[0020] In some embodiments, after removing the first and second electrodes, the following steps are further included:

[0021] Electrolyte is injected into the battery case containing the treated battery cells.

[0022] A second aspect of the present invention provides a battery prepared by the above-described preparation method.

[0023] A third aspect of the present invention provides a battery processing apparatus, which includes a reaction chamber and a first electrode and a second electrode disposed within the reaction chamber;

[0024] The reaction chamber is used to place the battery case in which the battery cells are assembled. The reaction chamber can be introduced with a preset gas, which can fill the battery case, contact the surface of the battery cells, and enter the internal pores of the battery cells.

[0025] The first electrode is used to electrically connect the positive or negative electrode of the battery cell;

[0026] The second electrode is used to interact with the first electrode to break down a portion of the preset gas and generate plasma.

[0027] The present invention has the following beneficial effects:

[0028] This invention, after the battery cell is installed in the casing but before electrolyte injection, electrically connects a first electrode to the positive or negative electrode of the battery cell. The first and second electrodes are used to break down a portion of a pre-set gas to generate plasma, which treats the battery cell. On one hand, the position of the pre-set gas contacting the battery cell and entering its internal pores coincides with the position of the subsequent electrolyte. Breaking down a portion of the pre-set gas into plasma and treating it helps improve the surface energy of the battery cell in contact with the electrolyte. On the other hand, connecting the positive or negative electrode to the first electrode refines the breakdown range, resulting in better treatment. Furthermore, the plasma treatment is performed close to the electrolyte injection process, avoiding the degradation of modified properties caused by the time-sensitivity of plasma treatment. Through this preparation method, the electrolyte injection efficiency and the wetting quality of the battery cell by the electrolyte can be effectively improved. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention and to more completely understand the present invention and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the battery casing processed using a battery processing device in Example 1;

[0031] Figure 2 This is a schematic diagram of the structure of the battery casing processed using a battery processing device in Example 2;

[0032] Figure 3 This is a schematic diagram of the structure of the battery casing processed using a battery processing device in Example 3. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to specific embodiments. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0035] the term

[0036] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0037] In this invention, the selection range of "and / or", "or / and", and "and / or" includes any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or", "or / and", and "and / or", it should be understood that the technical solution undoubtedly includes technical solutions connected by "logical AND", and also undoubtedly includes technical solutions connected by "logical OR". For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0038] In this invention, terms such as "multiple", "various", "multiple times", and "multi-dimensional" are used, unless otherwise specified, to refer to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0039] In this invention, the terms "combinations thereof", "any combination thereof", and "any combination thereof" include all suitable combinations of any two or more of the listed items.

[0040] In this invention, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this invention, solve the technical problem of this invention, and achieve the expected technical effect of this invention.

[0041] In this invention, terms such as "preferred," "better," "more suitable," and "ideal" are used only to describe implementation methods or embodiments with better effects, and should be understood not to limit the scope of protection of this invention.

[0042] In this invention, terms such as "further," "even more," and "particularly" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0043] In this invention, the terms "optionally," "optionally," and "optional" refer to options that are optional, meaning they are selected from either "with" or "without." If multiple "optional" options appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" option is independent.

[0044] In this invention, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0045] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0046] In this invention, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous, and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges included therein.

[0047] Unless otherwise specified, the temperature parameters in this invention can be either constant temperature treatment or variations within a certain temperature range. It should be understood that the constant temperature treatment allows temperature fluctuations within the precision range controlled by the instrument. Fluctuations are permitted within ranges such as ±5℃, ±4℃, ±3℃, ±2℃, and ±1℃.

[0048] In this invention, percentage content refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures, unless otherwise specified.

[0049] In this invention, percentage concentrations, unless otherwise specified, refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0050] The electrolyte filling process is a crucial step in battery manufacturing. It typically involves two steps: spraying and wetting. Since the separator material is usually polyethylene or polypropylene, PVDF is commonly used as a binder in the positive electrode fabrication, and graphite is typically used as the active material in the negative electrode, all these materials have relatively low surface energies. Furthermore, electrolytes often contain polar solvents, resulting in poor wetting of these materials. Spraying usually takes tens of minutes, and wetting typically takes 12 to 48 hours. The entire electrolyte filling process is generally time-consuming, and even with this extended timeframe, poor wetting quality can still occur. Poor wetting can lead to empty areas within the cell lacking electrolyte, hindering lithium-ion transport and preventing some active materials or conductive agents from functioning properly. This affects the battery's electrochemical performance, including capacity, cycle life, resistance, and rate capability. It may even cause lithium plating, compromising battery safety.

[0051] To address the issues of low electrolyte injection efficiency and poor wetting quality, this invention provides a battery and its preparation method. In one embodiment, the battery preparation method includes the following steps:

[0052] S100. A battery casing is provided, wherein a battery cell is assembled inside the battery casing and filled with a preset gas, the preset gas contacting the surface of the battery cell and entering the internal pores of the battery cell;

[0053] S200. Provide a first electrode, the first electrode being electrically connected to the positive electrode or the negative electrode of the battery cell;

[0054] S300. Provide a second electrode and adjust the position of the second electrode so that a portion of the preset gas is located within the discharge gap between the first electrode and the second electrode.

[0055] S400, the preset gas is broken down to generate plasma, and the plasma is used to process the battery cell.

[0056] S500: Remove the first electrode and the second electrode to prepare the battery.

[0057] In step S100, a battery cell is assembled inside the battery casing. The battery cell may include a positive electrode, a separator, and a negative electrode, with the separator located between the positive and negative electrode.

[0058] Understandably, the positive electrode, separator, and negative electrode all have pores. When the preset gas comes into contact with the surface of the battery cell and enters the internal pores of the battery cell, it means that the preset gas comes into contact with the surface of the battery cell and enters the pores of the positive electrode, separator, and negative electrode inside the battery cell.

[0059] Understandably, one or more battery cells may be installed inside the battery casing.

[0060] In this embodiment, a battery cell is assembled inside a battery casing. After assembly, the battery casing has an opening. A preset gas is filled into the battery casing through the opening, placing the battery cell in an environment filled with the preset gas. The preset gas diffuses to the surface of the battery cell and then enters the internal pores of the battery cell (e.g., the pores of the electrodes and separator), contacting the surface and interior of the battery cell. The location where the preset gas fills the battery casing at this time is the location of the subsequent electrolyte.

[0061] Further, optionally, the battery casing is fitted with a battery cell and filled with a preset gas, the preset gas contacting the surface of the battery cell and entering the internal pores of the battery cell, comprising the following steps:

[0062] The battery case, which is equipped with battery cells and has an opening, is placed inside the reaction chamber;

[0063] A preset gas is introduced into the reaction chamber. The preset gas first enters the battery casing through the opening, contacts the surface of the battery cell, and then enters the internal pores of the battery cell.

[0064] Optionally, the reaction chamber is a vacuum reaction chamber.

[0065] Understandably, immersing the battery casing, which contains the battery cells and has an opening, in a vacuum reaction chamber allows more of the pre-set gas to enter the battery cells, thus improving the plasma's treatment effect on the cells.

[0066] Optionally, the preset gas is selected from air, nitrogen, argon, oxygen, hydrogen, or a combination thereof. The preset gas can be introduced into the vacuum reaction chamber at a certain pressure. For example, the preset gas can be introduced into the vacuum reaction chamber at a pressure of 1 Pa to 100,000 Pa.

[0067] Alternatively, the preset gas flow rate can be 1 sccm to 1000 sccm.

[0068] Understandably, the openings in the battery casing can be large or small. They can be openings before the battery casing is sealed, or openings reserved after the casing is sealed for subsequent injection of electrolyte.

[0069] Alternatively, the battery casing can be a cylindrical battery casing, a square battery casing, or a pouch battery casing.

[0070] Optionally, the battery casing may be made of stainless steel, aluminum, aluminum-plastic film, or a combination thereof.

[0071] In step 200, the first electrode is electrically connected to the positive or negative electrode of the battery cell.

[0072] Understandably, a battery cell can have one or more positive electrode plates. Each positive electrode plate can be led out through its own positive electrode tab, and after the positive electrode tabs are soldered, they are electrically connected to the positive terminal of the battery casing. Similarly, a battery cell can have one or more negative electrode plates. Each negative electrode plate can be led out through its own negative electrode tab, and after the negative electrode tabs are soldered, they are electrically connected to the negative terminal of the battery casing.

[0073] The first electrode can be electrically connected to the positive or negative electrode of the battery cell by electrically connecting the first electrode to the positive or negative terminal of the battery casing.

[0074] Understandably, the positive and negative terminals can be located at opposite ends of the battery casing, or at the same end of the battery casing.

[0075] In this embodiment, the first electrode is electrically connected to the positive or negative terminal of the battery casing, which helps to refine the breakdown range. Subsequently, plasma can be generated within a refined range inside the battery cell, improving the utilization efficiency of the plasma and resulting in better processing effect.

[0076] In step 300, the position of the second electrode is adjusted so that a portion of the preset gas is located within the discharge gap between the first electrode and the second electrode.

[0077] Optionally, there are several ways to position a portion of the preset gas within the discharge gap between the first and second electrodes:

[0078] Method 1: The second electrode is electrically connected to the negative or positive electrode of the battery cell. Optionally, the second electrode can be electrically connected to the negative or positive terminal of the battery casing to achieve the electrical connection between the second electrode and the negative or positive electrode of the battery cell. In this case, the first and second electrodes are electrically connected to the positive and negative electrode of the battery cell, respectively.

[0079] Method 2: The second electrode is disposed on any surface of the battery cell, and is not in contact with or is insulated from the surface of the battery cell.

[0080] Method 3: The second electrode is disposed on any surface of the battery casing, and is not in contact with or is insulated from the surface of the battery casing.

[0081] Method 4: The second electrode is disposed on the positive or negative terminal and is either not in contact with or is insulated from the positive and negative terminals of the battery casing.

[0082] In the above methods one to four, the battery cell is formed by lamination or winding. When the battery cell is formed by lamination, the positive electrode, the separator, and the negative electrode are stacked and laminated to form the battery cell. When the battery cell is formed by winding, the positive electrode, the separator, and the negative electrode are stacked and wound to form the battery cell.

[0083] Method 5: The battery cell has a hollow cavity, and the second electrode is disposed within the hollow cavity. In this case, the second electrode can be electrically connected to, insulated from, or not in contact with the cavity wall of the hollow cavity.

[0084] In method five above, the battery cell is formed by winding. When the battery cell is formed by winding, the positive electrode, the separator, and the negative electrode are stacked and wound to form the battery cell.

[0085] In step 400, the predetermined gas is broken down to generate plasma.

[0086] Plasma is an ionized gaseous substance composed of positive and negative ions generated after atoms and atomic groups have lost some electrons and become ionized. In this embodiment, plasma is generated by the breakdown of a portion of the preset gas. The plasma is used to treat the battery cell, thereby increasing the surface energy of the treated battery cell, which is beneficial for enhancing the wetting and spreading of the electrolyte.

[0087] In this embodiment, since the location of some of the preset gas inside the battery case is the location of the subsequent electrolyte, the electrolyte comes into contact with the surface-modified battery cell, which can reduce the time required for the liquid injection process (liquid injection and wetting), improve the liquid injection efficiency of the electrolyte, and at the same time improve the wetting quality of the battery cell by the electrolyte.

[0088] Optionally, the plasma is used to process the battery cell for a period of 1s to 1800s.

[0089] The plasma can be used to treat the battery cell once or multiple times. The decision to repeat the treatment can be made based on the effectiveness of the previous treatment.

[0090] When processing is performed multiple times, after treating the battery cell with the plasma, the following steps are also included:

[0091] S401. Discharge the treated old preset gas;

[0092] S402, Introduce new preset gas;

[0093] S403. Break down the new preset gas in the discharge gap between the first electrode and the second electrode to generate new plasma, and use the new plasma to process the battery cell.

[0094] S404. Repeat steps S401 to S403.

[0095] Optionally, the number of repetitions can be 1 to 30.

[0096] Further optionally, the time for each treatment of the battery cell using the new plasma is 1s to 1800s.

[0097] A high-frequency voltage can be applied between the first electrode and the second electrode to break down a preset gas and generate plasma within the discharge gap between the first electrode and the second electrode.

[0098] Understandably, high-frequency voltage can be provided through a high-frequency power matching unit.

[0099] Understandably, cutting off the high-frequency voltage applied between the first and second electrodes can end the plasma treatment of the battery cell.

[0100] S500: Remove the first electrode and the second electrode to prepare a battery.

[0101] Optionally, the method further includes the following step: after removing the first electrode and the second electrode, injecting electrolyte through the opening in the battery casing.

[0102] Generally, plasma treatment is time-sensitive, meaning that the surface energy modification effect after plasma treatment diminishes with prolonged storage time. In this embodiment, the plasma treatment process is performed after the battery cell is installed in the casing, with the electrolyte injection process occurring close to the plasma treatment process. This avoids the attenuation of the plasma treatment effect and maximizes the improvement in electrolyte injection effect and wetting quality.

[0103] Optionally, after injecting the electrolyte, the process may also include aging, formation, and other steps.

[0104] In the above preparation method, after the battery cell is installed in the casing and before electrolyte injection, the first electrode is electrically connected to the positive or negative electrode of the battery cell. Plasma is generated by breaking down a portion of the preset gas using the first and second electrodes to treat the battery cell. On one hand, the position of the preset gas contacting the battery cell and entering its internal pores is the same as the position of the subsequent electrolyte. Breaking down a portion of the preset gas into plasma and treating it helps improve the surface energy of the battery cell in contact with the electrolyte. On the other hand, connecting the positive or negative electrode to the first electrode refines the breakdown range, resulting in better treatment. Furthermore, the plasma treatment is close to the electrolyte injection process, avoiding the degradation of modified properties caused by the time-sensitivity of plasma treatment. This preparation method effectively improves the electrolyte injection efficiency and the wetting quality of the battery cell by the electrolyte.

[0105] One embodiment of the present invention also provides a battery prepared by the above preparation method, which has good electrochemical performance.

[0106] One embodiment of the present invention also provides a battery processing device, which includes a reaction chamber and a first electrode and a second electrode disposed within the reaction chamber;

[0107] The reaction chamber is used to place the battery case in which the battery cells are assembled. The reaction chamber can be introduced with a preset gas, which can fill the battery case, contact the surface of the battery cells, and enter the internal pores of the battery cells.

[0108] The first electrode is used to electrically connect the positive or negative electrode of the battery cell;

[0109] The second electrode is used to interact with the first electrode to break down a portion of the preset gas and generate plasma.

[0110] Optionally, the reaction chamber further includes an air inlet and an air outlet, wherein the air inlet is used for the entry of a preset gas and the air outlet is used for the discharge of the preset gas.

[0111] Optionally, it further includes a high-frequency power matching unit, which is electrically connected to the first electrode and the second electrode respectively, for providing a high-frequency voltage.

[0112] The reaction chamber, the first electrode, and the second electrode are as described above and will not be repeated here.

[0113] The following description is further illustrated with specific embodiments and comparative examples. Unless otherwise specified, the raw materials involved in the following specific embodiments and comparative examples are all commercially available. Unless otherwise specified, the instruments used are all commercially available. Unless otherwise specified, the processes involved are conventionally selected by those skilled in the art.

[0114] The positive electrode is an aluminum foil with a positive active layer on both sides, the materials of which include lithium iron phosphate, polyvinylidene fluoride, and carbon nanotubes. The separator is polyethylene. The negative electrode is a copper foil with a negative active layer on both sides, the materials of which include graphite, sodium carboxymethyl cellulose, and carbon nanotubes. The electrolyte is a carbonate solution containing dissolved lithium hexafluorophosphate.

[0115] Example 1

[0116] This embodiment provides a battery and its preparation method, the steps of which are as follows:

[0117] Step 100: Stack and wind the positive electrode, separator and negative electrode to prepare the battery cell. Assemble the battery cell into the battery case, wherein the battery case has an opening and is a cylindrical aluminum battery case.

[0118] Step 200: Place the battery case with the assembled battery cells and an opening into the battery processing equipment. Please refer to [link to relevant documentation]. Figure 1 The battery processing device 01 includes a reaction chamber 11, a first electrode 12, a second electrode 13, and a high-frequency power matching unit 14. The reaction chamber 11 includes an air inlet 111 and an air outlet 112. The battery casing 04 includes a positive terminal 41 and a negative terminal 42, located at opposite ends of the battery casing 04, with an opening on the surface of the end containing the positive terminal 41. The battery casing 04 is placed inside the reaction chamber 11. One end of the first electrode 12 is electrically connected to the positive terminal 41, and the other end is electrically connected to the high-frequency power matching unit 14. One end of the second electrode 13 is electrically connected to the negative terminal 42, and the other end is electrically connected to the high-frequency power matching unit 14.

[0119] Step 300: The reaction chamber is evacuated to a pressure of 5 Pa. Then, hydrogen gas is introduced into the reaction chamber 11 through the air inlet 111 at a flow rate of 100 sccm. The pressure in the reaction chamber 11 is maintained at 100 Pa. The hydrogen gas enters the battery case 04 through the opening, contacts the surface of the battery cell, and enters the pores of the positive electrode, separator, and negative electrode inside the battery cell.

[0120] Step 400: Start the high-frequency power matching unit 14 to provide a high-frequency voltage of 13.56MHz, break down the hydrogen gas in the discharge gap between the first electrode 12 and the second electrode 13 to generate plasma, maintain the discharge power of 50W, use the plasma to process the battery cell, and cut off the high-frequency voltage after 20s.

[0121] Step 401: Discharge the treated old gas.

[0122] Step 402: Introduce new hydrogen gas into the reaction chamber 11 through the gas inlet 111.

[0123] Step 403: Start the high-frequency power matching unit 14 to provide a high-frequency voltage of 13.56MHz, break down the new hydrogen gas in the discharge gap between the first electrode 12 and the second electrode 13, generate new plasma, maintain the discharge power of 50W, use the new plasma to process the battery cell, and cut off the high-frequency voltage after 20s.

[0124] Step 404: Repeat steps 401 to 403, for a total of 5 times.

[0125] Step 500: Remove the first and second electrodes, take out the battery case with the battery cell and an opening, inject 65g of electrolyte through the opening, record the total injection time, immerse at 25°C for 24 hours, and obtain the battery after aging, formation and other steps.

[0126] Example 2

[0127] This embodiment provides a battery and its preparation method, the steps of which are as follows:

[0128] Step 100 is the same as step 100 in Example 1.

[0129] Step 200: Place the battery case with the assembled battery cells and an opening into the battery processing equipment. Please refer to [link to relevant documentation]. Figure 2 The battery processing device 02 includes a reaction chamber 21, a first electrode 22, a second electrode 23, and a high-frequency power matching unit 24. The reaction chamber 21 includes an air inlet 211 and an air outlet 212. The battery casing 04 includes a positive terminal 41 and a negative terminal 42, located at opposite ends of the battery casing 04, with an opening on the surface of the end containing the positive terminal 41. The battery casing 04 is placed inside the reaction chamber 21. One end of the first electrode 22 is inserted along the opening into the hollow cavity of the battery cell inside the battery casing 04, and the other end is electrically connected to the high-frequency power matching unit 24. One end of the second electrode 23 is electrically connected to the negative terminal 42, and the other end is electrically connected to the high-frequency power matching unit 24.

[0130] Step 300: The reaction chamber is evacuated to a pressure of 10 Pa. Then, nitrogen gas is introduced into the reaction chamber 21 through the air inlet 211 at a flow rate of 1 sccm. The pressure in the reaction chamber 21 is maintained at 100 Pa. The nitrogen gas enters the battery case 04 through the opening, contacts the surface of the battery cell, and enters the pores of the positive electrode, separator, and negative electrode inside the battery cell.

[0131] Step 400: Start the high-frequency power matching unit 24 to provide a high-frequency voltage of 40MHz, break down the nitrogen gas in the discharge gap between the first electrode 22 and the second electrode 23 to generate plasma, maintain the discharge power of 500W, use the plasma to process the battery cell, and cut off the high-frequency voltage after 30s.

[0132] Step 401: Discharge the treated old gas.

[0133] Step 402: Introduce new nitrogen gas into the reaction chamber 11 through the air inlet 111.

[0134] Step 403: Start the high-frequency power matching unit 14 to provide a high-frequency voltage of 40MHz, generate plasma from the new nitrogen gas in the discharge gap between the first electrode 22 and the second electrode 23, maintain the discharge power of 500W, use the plasma to process the battery cell, and cut off the high-frequency voltage after 30s.

[0135] Step 404: Repeat steps 401 to 403, repeating twice.

[0136] Step 500 is the same as step 500 in Example 1.

[0137] Example 3

[0138] This embodiment provides a battery and its preparation method, the steps of which are as follows:

[0139] Step 100 is the same as step 100 in Example 1.

[0140] Step 200: Place the battery case with the assembled battery cells and an opening into the battery processing equipment. Please refer to [link to relevant documentation]. Figure 3 The battery processing device 03 includes a reaction chamber 31, a first electrode 32, a second electrode 33, and a high-frequency power matching unit 34. The reaction chamber 31 includes an air inlet 311 and an air outlet 312. The battery casing 04 includes a positive terminal 41 and a negative terminal 42, located at opposite ends of the battery casing 04, with an opening on the surface of the end containing the positive terminal 41. The battery casing 04 is placed inside the reaction chamber 31. One end of the first electrode 32 is suspended above the positive terminal 41, and the other end is electrically connected to the high-frequency power matching unit 34. One end of the second electrode 33 is electrically connected to the negative terminal 42, and the other end is also electrically connected to the high-frequency power matching unit 34.

[0141] Step 300: The reaction chamber is evacuated to a pressure of 5 Pa. Then, air is introduced into the reaction chamber 31 through the air inlet 311 at a flow rate of 1000 sccm. The pressure in the reaction chamber 31 is maintained at 50 Pa. The air enters the battery case 04 through the opening, contacts the surface of the cell, and enters the pores of the positive electrode, separator, and negative electrode inside the cell.

[0142] Step 400: Start the high-frequency power matching unit 34 to provide a high-frequency voltage of 13.56MHz, break down the air in the discharge gap between the first electrode 32 and the second electrode 33 to generate plasma, maintain the discharge power of 100W, use the plasma to process the battery cell, and cut off the high-frequency voltage after 60s.

[0143] Step 500 is the same as step 500 in Example 1.

[0144] Example 4

[0145] This embodiment provides a battery and its preparation method, which is basically the same as that in embodiment 1. The main difference is that in step 1, the positive electrode sheet, the separator and the negative electrode sheet are stacked and laminated to prepare the battery cell.

[0146] Comparative Example 1

[0147] This comparative example provides a battery and its preparation method, which are basically the same as those in Example 1. The main difference is that the positive electrode, separator, and negative electrode are subjected to plasma treatment, and then the plasma-treated positive electrode, separator, and negative electrode are stacked, wound, and used to prepare the battery cell. The specific steps are as follows:

[0148] The positive electrode, separator, and negative electrode are placed in the reaction chamber 11 of the battery processing equipment 01, and positioned between the discharge gap of the first electrode 12 and the second electrode 13. Plasma treatment is performed according to steps 300-404 of Example 1. After plasma treatment, the positive electrode, separator, and negative electrode are removed and stacked and wound according to step 100 of Example 1 to prepare a battery cell. The battery cell is then assembled into a battery casing. Electrolyte is injected according to step 500 of Example 1, and the battery undergoes aging and formation processes to obtain the battery.

[0149] Comparative Example 2

[0150] This comparative example provides a battery and its preparation method, which is basically the same as that in Example 4. The main difference is that the positive electrode, separator, and negative electrode are subjected to plasma treatment, and then the plasma-treated positive electrode, separator, and negative electrode are stacked and laminated to prepare the battery cell. The specific steps are as follows:

[0151] The positive electrode, separator, and negative electrode are placed in the reaction chamber 11 of the battery processing equipment 01, and positioned between the discharge gap of the first electrode 12 and the second electrode 13. Plasma treatment is performed according to steps 300-404 of Example 1. After plasma treatment, the positive electrode, separator, and negative electrode are removed and stacked and laminated according to step 100 of Example 4 to prepare a battery cell. The battery cell is then assembled into a battery casing. Electrolyte is injected according to step 500 of Example 1, and the battery undergoes aging and formation processes to obtain the battery.

[0152] Table 1 shows the injection time records for each embodiment and comparative example.

[0153] The electrochemical workstations used to prepare batteries in each embodiment and comparative example were used to measure AC impedance spectra. The high-frequency region was set to 100 kHz, and the low-frequency region was set to 10 mHz. The curves were obtained by scanning. The intersection of the ultra-high frequency region and the real axis is the ohmic impedance. The ohmic impedances are recorded in Table 1.

[0154] As shown in Table 1, Examples 1-4 involve shorter electrolyte injection times. Furthermore, with higher injection efficiency and shorter wetting times, the resulting batteries exhibit lower impedance, thus mitigating the problems of low electrolyte injection efficiency and poor wetting quality. Compared to Comparative Example 1, Example 1, and Example 4, compared to Comparative Example 2, utilizes the battery cell as one of the plasma excitation sources. Compared to plasma treatment of the electrodes or separator before assembly, this method, being closer to the electrolyte injection process, results in better plasma modification and retention, significantly reducing injection time, increasing injection speed, and consequently, producing batteries with lower impedance.

[0155] Table 1

[0156]

[0157] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0158] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method of producing a battery, characterized by, Includes the following steps: A battery casing is provided, wherein a battery cell is assembled inside the battery casing and filled with a preset gas, the preset gas contacting the surface of the battery cell and entering the internal pores of the battery cell; A first electrode is provided, which is electrically connected to the positive or negative electrode of the battery cell; A second electrode is provided, and the position of the second electrode is adjusted so that a portion of the preset gas is located within the discharge gap between the first electrode and the second electrode; The preset gas is partially broken down to generate plasma, which is then used to process the battery cell. After removing the first and second electrodes, electrolyte is injected into the battery case containing the processed battery cell to prepare the battery.

2. The method of claim 1, wherein the battery is a lithium ion battery. The second electrode is electrically connected to the negative or positive electrode of the battery cell.

3. The method of claim 1, wherein the battery is a lithium ion battery. The second electrode is disposed on any surface of the battery cell and is either in contact with or insulated from the surface of the battery cell.

4. The method of claim 1, wherein the battery is a lithium ion battery. The second electrode is disposed on any surface of the battery casing and is either in contact with or insulated from the surface of the battery casing.

5. The method for preparing a battery according to claim 1, characterized in that, The second electrode is disposed on the positive or negative terminal of the battery casing and is either in contact with or insulated from the positive or negative terminal.

6. The method for preparing a battery according to any one of claims 1 to 5, characterized in that, The battery cells are formed by lamination or winding.

7. The method for preparing a battery according to claim 1, characterized in that, The battery cell has a hollow cavity, and the second electrode is disposed inside the hollow cavity.

8. The method for preparing a battery according to claim 7, characterized in that, The battery cell is formed by winding.

9. The method for preparing a battery according to any one of claims 1-5 and 7-8, characterized in that, The preset gas is selected from air, nitrogen, argon, oxygen, hydrogen, or a combination thereof.

10. A battery, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 9.

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