A method for fine recycling of batteries

Abstract

The present invention provides a method for fine recycling of batteries, comprising: discharging the batteries; detaching the battery cells and the cover plates from the housings; stripping the films wrapped around the battery cells; separating the battery cells from the cover plates, including: unfolding the battery cells to expose the tabs, cutting off the tabs, and separating the battery cells from the cover plates; disassembling the battery cells to recycle the positive plates and the negative plates. First, keep the cover plates connected to the battery cells, and use the cover plates to conveniently and quickly take out the battery cells from the outer casings. Then, strip the films wrapped around the battery cells, unfold the battery cells to both sides of the cover plates, so that there is a sufficiently wide gap between the battery cells and the cover plates, thereby facilitating the cutting off of the tabs. Finally, roll the battery cells back to disassemble and obtain complete positive plates and negative plates. Stripping the films and unfolding the battery cells provide better cutting conditions for the complete separation of the battery cells from the cover plates, and it is not easy to cut the battery cells, which not only avoids material loss but also avoids the safety risks caused by the contact between the positive plates and the negative plates during the cutting process.

Description

Technical Field

[0001] The present invention relates to the field of waste battery treatment, and particularly to a method for fine recycling of batteries. Background Art

[0002] With the vigorous development of the new energy vehicle industry, the number of waste vehicle power batteries is increasing day by day. Waste batteries contain a large amount of heavy metals, organic substances, electrolytes, and toxic gases generated by their conversion products. It is necessary to recycle waste batteries both from the perspective of environmental protection and economic benefits.

[0003] A vehicle power battery generally includes structures such as a battery cell, an electrode tab, and a housing. The battery cell is formed by winding a strip-shaped positive electrode sheet and a negative electrode sheet, and the positive electrode sheet and the negative electrode sheet are separated by a separator. The housing consists of a shell and a cover plate. The shell is used to accommodate two, four, or more battery cells, and the cover plate encapsulates the battery cells therein. The positive electrode sheets and the negative electrode sheets of each battery cell are respectively connected to the cover plate through electrode tabs. In addition, each battery cell is coated with a mylar film to further fix it.

[0004] Existing waste battery recycling methods are relatively crude. Some recycling methods directly cut and break the entire battery, and some recycling methods cut off both ends of the battery as a whole, then push the battery cell out of the housing, and then cut and break the battery cell. During the process of cutting off both ends of the battery as a whole, it is easy to cut the battery cell, resulting in the loss of positive and negative electrode materials, and there may be a safety risk caused by the contact between the positive electrode sheet and the negative electrode sheet. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a method for fine recycling of batteries.

[0006] The present invention provides the following technical solutions:

[0007] A method for fine recycling of batteries includes the following steps:

[0008] S0, discharging the battery;

[0009] S1, detaching the battery cell and the cover plate from the shell;

[0010] S2, stripping the film wrapped on the battery cell;

[0011] S3, separating the battery cell from the cover plate;

[0012] S4, disassembling the battery cell and recycling the positive electrode sheet and the negative electrode sheet;

[0013] Among them, step S3 includes:

[0014] S3-1, unfolding the battery cell to expose the electrode tab;

[0015] S3-2. Cut the tab to separate the battery cell from the cover plate.

[0016] As a further optional solution to the battery fine recycling method, discharging the battery includes:

[0017] Use a discharging device to discharge the voltage of the battery below 3V.

[0018] As a further optional solution to the battery fine recycling method, step S1 includes:

[0019] S1-1. Cut the outer shell to separate the cover plate from the housing;

[0020] S1-2. Fix the cover plate and move the housing to take out the battery cell from the housing.

[0021] As a further optional solution to the battery fine recycling method, cutting the outer shell includes:

[0022] Orient the cutting edge of the cutter towards the side of the housing, cut in from one end of the housing close to the cover plate, and then move along the circumference of the cover plate.

[0023] As a further optional solution to the battery fine recycling method, after step S1-2, it further includes:

[0024] S1-3. Collect the housing and the electrolyte respectively.

[0025] As a further optional solution to the battery fine recycling method, after stripping the film wrapped around the battery cell, it further includes:

[0026] Collect the film.

[0027] As a further optional solution to the battery fine recycling method, unfolding the battery cell includes:

[0028] Separate the ends of the two battery cells away from the cover plate from each other and unfold the two battery cells to both sides of the cover plate.

[0029] As a further optional solution to the battery fine recycling method, after step S3-2, it further includes;

[0030] S3-3. Collect the cover plate.

[0031] As a further optional solution to the battery fine recycling method, disassembling the battery cell includes:

[0032] Roll the battery cell in the opposite direction to disassemble it into a positive electrode sheet, a negative electrode sheet, an inner separator and an outer separator.

[0033] Embodiments of the present invention have the following beneficial effects:

[0034] First, only separate the cover plate from the housing, keeping the cover plate connected to the battery cell. Before the battery cell is completely separated from the cover plate, take advantage of the easy-to-grip feature of the cover plate to quickly remove the battery cell from the outer casing. Then, by peeling off the film wrapped around the battery cell, the battery cells are no longer connected as a whole. Unfold the battery cells to both sides of the cover plate, creating a wide enough gap between the battery cells and the cover plate to facilitate cutting the tabs and completely separating the battery cells from the cover plate. Finally, roll the battery cells in the opposite direction to disassemble and obtain complete positive and negative plates. The above operation process is interlocked. Peeling off the film and unfolding the battery cells provide better cutting conditions for completely separating the battery cells from the cover plate, making it less likely to cut the battery cells, thus avoiding both material loss and safety risks caused by contact between the positive and negative plates during cutting.

[0035] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, in conjunction with the accompanying drawings, and are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0037] Figure 1 Shows the overall flowchart of a battery fine recycling method provided by an embodiment of the present invention;

[0038] Figure 2 Shows the flowchart of step S1 in a battery fine recycling method provided by an embodiment of the present invention;

[0039] Figure 3 Shows the flowchart of step S3 in a battery fine recycling method provided by an embodiment of the present invention;

[0040] Figure 4 Shows a schematic diagram of the battery cells after unfolding in a battery fine recycling method provided by an embodiment of the present invention;

[0041] Figure 5 Shows a schematic diagram of the structure of the battery cells in a battery fine recycling method provided by an embodiment of the present invention.

[0042] MAIN ELEMENT SYMBOL DESCRIPTION:

[0043] 100 - Battery cell; 110 - Inner separator; 120 - Negative electrode; 130 - Outer separator; 140 - Positive electrode; 200 - Tab; 300 - Cover plate. Detailed implementation mode

[0044] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0045] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. On the contrary, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0046] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise clearly and specifically defined.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of the template herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0049] Embodiment

[0050] Please refer to Figure 1, This embodiment provides a battery fine recycling method for recycling waste batteries. In this embodiment, the waste battery is a lithium battery, specifically a vehicle power battery, including but not limited to passenger cars, commercial vehicles, electric bicycles, etc. In other embodiments of the present application, the waste battery can also be a mobile phone battery, etc.

[0051] Among them, the vehicle power battery includes a battery cell 100 (refer to Figure 5 ), a tab 200 (refer to Figure 5 ), and a housing and other structures. The battery cell 100 is wound by a strip-shaped positive electrode sheet 140 (refer to Figure 5 ) and a negative electrode sheet 120 (refer to Figure 5 ), and the positive electrode sheet 140 and the negative electrode sheet 120 are separated by a separator. The aluminum housing is composed of a shell and a cover plate 300 (refer to Figure 5 ). Two battery cells 100 are accommodated in the shell. After the battery cells 100 are placed inside the shell, the cover plate 300 encapsulates the battery cells 100 in the shell, and the positive electrode sheets 140 and the negative electrode sheets 120 of each battery cell 100 are respectively connected to the cover plate 300 through the tabs 200. In addition, two battery cells 100 are coated with a thin film. In this embodiment, the thin film is a mylar film.

[0052] Specifically, the battery fine recycling method includes the following steps:

[0053] S0, Discharge the battery.

[0054] Specifically, use a discharging device to discharge the battery until the voltage is below 3V. At this time, the battery power is almost zero.

[0055] In this embodiment, when the voltage of the battery is about 2.7V, the discharging can be stopped.

[0056] By discharging the battery, the lithium in the battery returns to the positive electrode sheet 140, which is convenient for subsequent recycling. In addition, during the subsequent disassembly of the battery, it will also be safer.

[0057] The existing waste battery recycling method discharges the battery by placing it in salt water, but the salt water discharging cycle is long, the efficiency is low, and pollution will be generated. In contrast, discharging the battery using a discharging device has higher efficiency and less pollution, and is suitable for industrial batch recycling of waste batteries.

[0058] S1, Separate the battery cell 100 and the cover plate 300 from the shell.

[0059] Please refer to Figure 2 , The specific steps are as follows:

[0060] S1-1, Cut the housing to separate the cover plate 300 from the shell.

[0061] Specifically, in this embodiment, the outer shell is cut with a cutter, with the cutting edge facing the side of the shell, and the cutter cuts into the shell from one end close to the cover plate 300, and then moves along the circumference of the cover plate 300, so that the cover plate 300 is separated from the shell.

[0062] In another embodiment of the present application, a plurality of cutters may be arranged around the shell so that the plurality of cutters cut into the respective sides of the shell respectively to completely cut off the shell, thereby separating the cover plate 300 from the shell.

[0063] Cutting the cover plate 300 with a cutter generates less dust and has low purchase and maintenance costs.

[0064] In a specific implementation of this embodiment, the cover plate 300 is only disposed at one end of the housing, and the positive electrode sheets 140 and the negative electrode sheets 120 of the two battery cells 100 are connected to the cover plate 300 through the tabs 200 .

[0065] In another specific implementation of this embodiment, the cover plates 300 can also be arranged at both ends of the housing at the same time, and the positive electrode sheets 140 of the two battery cells 100 are connected to one of the cover plates 300 through the tabs 200, and the negative electrode sheets 120 of the two battery cells 100 are connected to the other cover plate 300 through the tabs 200. In this case, the two cover plates 300 need to be cut off from the housing with a cutter.

[0066] S1-2, fix the cover plate 300, move the shell, and make the battery cell 100 escape from the shell.

[0067] The existing waste battery recycling method is to cut from the side of the shell and completely cut off the end of the shell, so that the cover plate 300 is separated from the shell and the cover plate 300 is disconnected from the battery cell 100. However, the distance between the battery cell 100 and the cover plate 300 is very small, and the positioning accuracy requirement during cutting is very high. It is very easy to cut the battery cell 100, resulting in material loss, and there may be a safety risk caused by the contact between the positive electrode sheet 140 and the negative electrode sheet 120. In addition, it is difficult to exert force on the battery cell 100 after it is disconnected from the cover plate 300, which increases the difficulty of removing the battery cell 100 from the shell. It is often necessary to cut off the other end of the shell and then push the battery cell 100 out of the shell. It is also easy to cut the battery cell 100, resulting in material loss, and there may be a safety risk caused by the contact between the positive electrode sheet 140 and the negative electrode sheet 120.

[0068] In contrast, only cutting the cover plate 300 off the outer shell does not easily cut the battery cell 100, and the battery cell 100 can be easily and quickly removed from the shell after cutting, avoiding material loss, while eliminating the safety risks caused by contact between the positive electrode sheet 140 and the negative electrode sheet 120 during the cutting process.

[0069] Specifically, since the battery cell 100 is wrapped with a mylar film and the mylar film is stained with electrolyte, the frictional force between the battery cell 100 and the housing is very small, and the battery cell 100 is easily detached from the housing.

[0070] S1-3, collect the housing and the electrolyte respectively.

[0071] S2, strip the mylar film wrapped on the battery cell 100 and collect the mylar film.

[0072] Specifically, when stripping the mylar film, first use a heating wire to fuse the mylar film, and then remove the mylar film from the two battery cells 100.

[0073] When using the heating wire to fuse the mylar film, it is not affected by the flexibility of the mylar film itself, and there is no need to find the edge of the mylar film, and the mylar film can be quickly and effectively fused.

[0074] S3, separate the battery cell 100 from the cover plate 300.

[0075] Please refer to Figure 3 , the specific steps are as follows:

[0076] S3-1, unfold the battery cell 100 to expose the ear 200.

[0077] Please refer to Figure 4 , specifically, after the mylar film is stripped, the two battery cells 100 are not connected to each other. Make the ends of the two battery cells 100 away from the cover plate 300 face away from each other, and unfold the two battery cells 100 to both sides of the cover plate 300. At this time, the ends of the two battery cells 100 close to the cover plate 300 are still connected to the cover plate 300 through the ears 200 respectively, and the ears 200 are exposed.

[0078] S3-2, cut off the ear 200 to separate the battery cell 100 from the cover plate 300.

[0079] Specifically, cut off the four ears 200 along the dotted line in the figure with a cutter, thereby disconnecting the connection between the battery cell 100 and the cover plate 300.

[0080] In another specific embodiment of the present application, the number of battery cells 100 encapsulated in the housing is four. The four battery cells 100 are divided into two groups, with two in each group, and the two battery cells 100 in the same group are stacked together. The two groups of battery cells 100 are respectively unfolded to both sides of the cover plate 300. First, cut off the ears 200 to separate the two groups of battery cells 100 from the cover plate 300 respectively, and then separate the two battery cells 100 in the same group.

[0081] As described above, the existing waste battery recycling method cuts from the side of the outer casing and completely cuts off the end of the outer casing, so that the cover plate 300 is disconnected from the battery cell 100. However, the distance between the battery cell 100 and the cover plate 300 is very small, and the requirement for positioning accuracy during cutting is very high. It is extremely easy to cut the battery cell 100, resulting in material loss, and there may be a safety risk caused by the contact between the positive electrode plate 140 and the negative electrode plate 120.

[0082] In contrast, there is a wider gap between the unfolded battery cell 100 and the cover plate 300, and the width of the gap is equal to the length of the middle part of the tab 200 that is not connected to the battery cell 100 and the cover plate 300. Therefore, the requirement for positioning accuracy is much lower. The cutting tool is not easy to cut the battery cell 100, avoiding material loss, and at the same time avoiding the safety risk caused by the contact between the positive electrode plate 140 and the negative electrode plate 120 during cutting.

[0083] S3-3, collect the cover plate 300.

[0084] S4, disassemble the battery cell 100 and recycle the positive electrode plate 140 and the negative electrode plate 120.

[0085] Please refer to Figure 5 , the battery cell 100 is wound clockwise by a strip-shaped inner separator 110, a negative electrode plate 120, an outer separator 130, and a positive electrode plate 140, and the inner separator 110, the negative electrode plate 120, the outer separator 130, and the positive electrode plate 140 are stacked in sequence. The outer separator 130 separates the negative electrode plate 120 and the positive electrode plate 140 in the same circle, and the inner separator 110 separates the positive electrode plate 140 and the negative electrode plate 120 in adjacent circles, specifically separating the positive electrode plate 140 in the inner circle from the negative electrode plate 120 in the outer circle.

[0086] In addition, the inner separator 110, the negative electrode plate 120, the outer separator 130, and the positive electrode plate 140 all have a starting end and a terminating end. The terminating ends of the inner separator 110, the negative electrode plate 120, the outer separator 130, and the positive electrode plate 140 are staggered and end winding at different positions.

[0087] In this embodiment, the positive electrode plate 140, the negative electrode plate 120, the inner separator 110, and the outer separator 130 end winding in sequence.

[0088] Specifically, when disassembling the battery cell 100, the battery cell 100 is unrolled in the reverse direction and disassembled into the positive electrode plate 140, the negative electrode plate 120, the inner separator 110, and the outer separator 130, and then the positive electrode plate 140, the negative electrode plate 120, the inner separator 110, and the outer separator 130 are collected.

[0089] First, separate the terminating end of the outer separator 130 from the main body part of the battery cell 100, disassemble the outer separator 130 from the battery cell 100 in the counterclockwise direction, and collect the outer separator 130.

[0090] After the termination end of the inner separator 110 is exposed, separate the termination end of the inner separator 110 from the main body part of the battery cell 100, disassemble the inner separator 110 from the battery cell 100 in the counterclockwise direction, and collect the inner separator 110.

[0091] After the termination end of the negative electrode sheet 120 is exposed, separate the termination end of the negative electrode sheet 120 from the main body part of the battery cell 100, disassemble the negative electrode sheet 120 from the battery cell 100 in the counterclockwise direction, and collect the negative electrode sheet 120.

[0092] After the termination end of the positive electrode sheet 140 is exposed, separate the termination end of the positive electrode sheet 140 from the main body part of the battery cell 100, disassemble the positive electrode sheet 140 from the battery cell 100 in the counterclockwise direction, and collect the positive electrode sheet 140.

[0093] After that, disassemble the positive electrode sheet 140, the negative electrode sheet 120, the inner separator 110 and the outer separator 130 simultaneously, and collect the positive electrode sheet 140, the negative electrode sheet 120, the inner separator 110 and the outer separator 130 respectively.

[0094] The existing waste battery recycling method directly cuts and crushes the battery cell 100 into multiple small pieces. The positive electrode sheet 140 and the negative electrode sheet 120 in the small pieces are not separated, resulting in a complex subsequent recycling process, low recycling efficiency and high recycling cost. In contrast, after the battery cell 100 is unrolled, the independent and complete positive electrode sheet 140 and negative electrode sheet 120 can be obtained, which is beneficial to the subsequent recycling process, has a higher recycling efficiency for precious metals, and a lower recycling cost.

[0095] When recycling waste batteries using the above battery fine recycling method, first only separate the cover plate 300 from the housing, keep the cover plate 300 connected to the battery cell 100, and make use of the easy-to-grip and force-applying characteristics of the cover plate 300 to quickly and conveniently remove the battery cell 100 from the housing before the battery cell 100 and the cover plate 300 are completely separated. Then, by peeling off the mylar film, the two battery cells 100 are no longer connected as a whole, and the battery cell 100 is unfolded to both sides of the cover plate 300, so that there is a wide enough gap between the battery cell 100 and the cover plate 300, which is convenient for the cutting tool to cut off the tab 200 and completely separate the battery cell 100 from the cover plate 300. Finally, the battery cell 100 is unrolled, and the complete positive electrode sheet 140 and negative electrode sheet 120 are disassembled.

[0096] The above operation process is interlocked. Peeling off the mylar film and unfolding the battery cell 100 provide better cutting conditions for the complete separation of the battery cell 100 from the cover plate 300, making it difficult for the cutting tool to cut the battery cell 100, which not only avoids material loss but also avoids the safety risk caused by the contact between the positive electrode sheet 140 and the negative electrode sheet 120 during cutting.

[0097] In addition, the entire battery is finely disassembled, and the housing, electrolyte, Mylar film, cover plate 300, positive electrode sheet 140, negative electrode sheet 120, and separator can all be recycled. Moreover, the recycling difficulty is low and the remaining waste is less, thereby reducing environmental pollution and improving economic benefits.

[0098] In all the examples shown and described here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0099] It should be noted that like reference numerals and letters indicate like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0100] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for fine recycling of batteries, characterized in that, It includes the following steps: S0, discharge the battery; S1, separate the battery cell and the cover plate from the housing; S2, strip the film wrapped around the battery cell; S3, separate the battery cell from the cover plate; S4, disassemble the battery cell and recycle the positive electrode plate and the negative electrode plate; Among them, step S3 includes: S3-1, unfold the battery cell to expose the tabs; S3-2, cut off the tabs to separate the battery cell from the cover plate; The unfolding of the battery cell includes: Make the ends of the battery cell away from the cover plate deviate from each other, and unfold the battery cell to both sides of the cover plate.

2. The battery fine recycling method according to claim 1, characterized in that, The discharging of the battery includes: Use a discharging device to discharge the voltage of the battery below 3V.

3. The battery fine recycling method according to claim 1, characterized in that, Step S1 includes: S1-1, cut the outer shell to separate the cover plate from the housing; S1-2, fix the cover plate and move the housing to take out the battery cell from the housing.

4. The battery fine recycling method according to claim 3, characterized in that The cutting of the outer shell includes: Make the cutting edge of the cutter face the side of the housing, cut in from the end of the housing close to the cover plate, and then move along the circumference of the cover plate.

5. The battery fine recycling method according to claim 3, characterized in that, After step S1-2, it further includes: S1-3, collect the housing and the electrolyte respectively.

6. The battery fine recycling method according to claim 1, characterized in that, After stripping the film wrapped around the battery cell, it further includes: Collect the film.

7. The battery fine recycling method according to claim 1, wherein, After step S3-2, it further includes; S3-3, collect the cover plate.

8. The battery fine recycling method according to claim 1, characterized in that, The disassembling of the battery cell includes: Unroll the battery cell in reverse and disassemble it into a positive electrode plate, a negative electrode plate, an inner separator and an outer separator.

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