Battery formation clamp and formation device

Abstract

The utility model provides a battery formation fixture and formation device, the battery formation fixture comprises a pair of clamping pieces that are symmetrically arranged, any one of the clamping pieces comprises a laminate, a rolling mechanism and a limiting mechanism, an accommodating space is formed between the laminates of the two clamping pieces that are oppositely arranged to accommodate a battery, and the limiting mechanism is arranged between the laminates of the two clamping pieces that are oppositely arranged. The laminate is provided with a first end and a second end in a first direction; the rolling mechanism is rotationally mounted on the laminate and faces the accommodating space, and the rolling mechanism can be driven by external force to rotate towards the direction where the first end is located; the limiting mechanism is mounted on the laminate and is used for limiting the battery; and when the two clamping pieces are close to each other, the rolling mechanism can be in contact with the surface of the battery located in the accommodating space and move relative to the battery in the first direction so as to roll the surface of the battery. The battery formation clamp and the formation device provided by the utility model are suitable for formation operation of batteries with different sizes.

Description

Technical Field

[0001] The utility model relates to the technical field of battery production, in particular to a battery formation fixture and a formation device. Background Art

[0002] Formation is the first charging process of the battery during the battery production process. During this process, the active materials in the battery will be activated, causing chemical reactions inside the battery and generating a solid electrolyte interface film (SEI film). The SEI film can prevent the chemical reaction process inside the battery from getting out of control, while protecting the interface between the electrolyte and the electrode material, thereby improving the cycle life and safety performance of the battery. During this process, a certain amount of gas will be generated in the battery, which will affect the formation of the SEI film and further affect the subsequent working performance of the battery. Therefore, the above gas needs to be discharged from the battery as soon as possible.

[0003] Due to the structure of the battery, the pole pieces cannot be arranged closely, and gaps will be formed between the pole pieces and structures such as the diaphragm. The gases generated during the battery formation process will remain in the above gaps and are difficult to discharge.

[0004] In the related art, in order to prevent residual gas in the battery from affecting the formation of the SEI film, a high negative pressure state is maintained inside the battery during the battery formation process to discharge the generated gas in real time. However, this will cause the electrolyte inside the battery to be drawn out of the shell and cause the electrolyte to be lost. Utility Model Content

[0005] The utility model aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, the embodiments of the present invention provide a battery formation fixture and a formation device, which can be applicable to battery formation operations of different sizes.

[0007] The battery formation fixture provided by the embodiment of the utility model comprises a pair of symmetrically arranged clamping members, any one of the clamping members comprises a layer plate, a rolling mechanism and a limiting mechanism, a receiving space is formed between the layer plates of the two relatively arranged clamping members to receive the battery, the layer plate has a first end and a second end in a first direction; the rolling mechanism is rotatably mounted on the layer plate and faces the receiving space, and the rolling mechanism can rotate toward the position of the first end under the driving of an external force; the limiting mechanism is mounted on the layer plate and is used to limit the battery; when the two clamping members are close to each other, the rolling mechanism can contact the surface of the battery located in the receiving space and move relative to the battery along the first direction to roll the surface of the battery.

[0008] The battery formation fixture according to the embodiment of the utility model is suitable for batteries of different sizes, and can roll the battery surface during formation, so as to discharge the gas located in the internal layer / interlayer of the battery, so that the pole piece and the diaphragm can be in close contact, thereby achieving the effect of improving the battery interface after formation, solving the problem of local lithium precipitation that may occur in the battery, and further improving the service life of the battery. In addition, compared with the solution of high negative pressure gas suction, the use of the battery formation fixture can also overcome the problem of electrolyte loss caused by high negative pressure suction.

[0009] In some embodiments, a moving path of the rolling mechanism in the first direction is not less than a size of the to-be-rolled area of ​​the battery in the first direction.

[0010] In some embodiments, the limiting mechanism includes a limiting block and an elastic telescopic member, and the limiting block is installed on the layer plate via the elastic telescopic member; when the clamping members on both sides are close to each other, the limiting block can be against the battery located in the accommodating space to fix the battery.

[0011] In some embodiments, the rolling mechanism is rotatably mounted on the layer plate via a fixed shaft, and a plurality of elastic members are disposed on the fixed shaft outer sleeve, and the elastic members apply a force to the rolling mechanism to rotate in a direction away from the first end.

[0012] In some embodiments, the elastic member is a torsion spring.

[0013] In some embodiments, the rolling mechanism includes a connecting rod and a pressing roller, the two ends of the connecting rod are respectively connected to the pressing roller and the fixed shaft, and the outer peripheral side wall of the pressing roller is used to roll the battery surface.

[0014] In some embodiments, a contact surface is formed on a side of the layer plate facing the accommodating space, and the contact surface is a plane; in the thickness direction of the battery, a projection of the battery falls within an outer contour of a projection of the contact surface.

[0015] In some embodiments, a portion of the contact surface is recessed inward to form a groove for accommodating the rolling mechanism; when the rolling mechanism rotates into the groove, the contact surface can fit with the battery surface.

[0016] In some embodiments, part of the surface of the layer plate in the second direction is recessed inward and forms a mounting groove for mounting the rolling mechanism and / or the limiting mechanism, wherein the mounting groove is arranged adjacent to the contact surface and communicates with the groove.

[0017] The formation device provided in the embodiment of the utility model comprises any one of the battery formation fixtures described above.

[0018] According to the formation device of the embodiment of the utility model, the formation device can effectively improve the battery interface after formation through the above-mentioned battery formation fixture, and solve the problem of local lithium deposition in the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is a schematic diagram of the use of the battery formation fixture of the utility model embodiment;

[0021] Figure 2 It is a structural schematic diagram of a clamping member in a battery formation fixture according to an embodiment of the utility model;

[0022] Figure 3 It is a structural schematic diagram of a clamping member of a battery formation clamp according to another embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of the state in which the battery formation fixture of the embodiment of the utility model rolls the battery;

[0024] Figure 5 It is a schematic diagram of the arrangement of the pressure rollers and the batteries in the first direction in the battery formation fixture of an embodiment of the utility model.

[0025] In the figure:

[0026] 10. Clamping member; 101. Accommodating space; 1. Shelf; 11. First end; 12. Second end; 13. Contact surface; 14. Groove; 15. Mounting groove; 2. Rolling mechanism; 21. Connecting rod; 22. Pressing roller; 3. Limiting mechanism; 31. Limiting block; 32. Elastic expansion member; 4. Fixed shaft; 41. Torsion spring;

[0027] 20. Battery;

[0028] X, first direction; Y, second direction. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0031] In the description of the embodiments of the present utility model, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] In the description of the embodiments of the present utility model, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0034] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present invention.

[0035] In the description of the embodiments of the present utility model, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present utility model can be understood according to specific circumstances.

[0036] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0038] Combine the following Figure 1-Figure 5 The battery formation fixture and formation device according to the embodiment of the utility model are described, and the battery formation fixture and formation device can be applied to the formation operation of batteries of different sizes. The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the utility model, and cannot be understood as limiting the utility model.

[0039] The battery mentioned in the embodiment of the present utility model refers to a single physical module including one or more battery cell components to provide higher voltage and capacity. Among them, multiple battery cell components can be directly connected in series, in parallel or in mixed connection to form a battery. Mixed connection means that multiple battery cell components are both connected in series and in parallel. Multiple battery cell components can also be connected in series, in parallel or in mixed connection to form a battery module, and multiple battery modules can be connected in series, in parallel or in mixed connection to form a battery. The battery can also include a box for encapsulating one or more battery cell components. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cell components.

[0040] The battery cell assembly may include any one of a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., and the embodiments of the present utility model are not limited to this.

[0041] The battery cell assembly includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell assembly mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer in the axial direction of the battery cell assembly. The positive electrode collector not coated with the positive electrode active material layer serves as the pole ear part of the positive electrode sheet. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer in the axial direction of the battery cell assembly. The negative electrode current collector not coated with the negative electrode active material layer serves as the pole ear part of the negative electrode sheet. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The material of the diaphragm can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.

[0042] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric scooters, electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0043] During the manufacturing process of batteries, how to smoothly discharge the gas generated during the formation process is an important factor affecting whether the battery can be used stably for a long time.

[0044] The applicant noted that, taking soft-pack batteries as an example, since soft-pack batteries use an aluminum-plastic packaging structure, their external structure determines that the pole pieces cannot be arranged closely, and gaps are easily generated between the pole pieces / diaphragms / pole pieces. The gas generated during the battery formation process is also easy to remain between the layers / layers. After the battery is sealed, the gas cannot be completely discharged, thereby affecting the service life of the battery.

[0045] In order to overcome the above problems and avoid electrolyte leakage, the utility model provides a battery formation fixture, which can be suitable for batteries 20 of various sizes. By rolling the two side walls of the battery 20 in the thickness direction, the gas formed in the battery 20 can be effectively discharged.

[0046] Specifically, Figure 1-Figure 5 As shown, the battery formation fixture includes a pair of symmetrically arranged clamping members 10, any one of the clamping members 10 includes a layer plate 1, a rolling mechanism 2 and a limiting mechanism 3, and a receiving space 101 is formed between the layer plates 1 of the two relatively arranged clamping members 10 to accommodate the battery 20, and the layer plate 1 has a first end 11 and a second end 12 in a first direction X; the rolling mechanism 2 is rotatably installed on the layer plate 1 and faces the receiving space 101, and the rolling mechanism 2 can rotate toward the position of the first end 11 under the drive of an external force; the limiting mechanism 3 is installed on the layer plate 1, and is used to limit the battery 20; when the two clamping members 10 are close to each other, the rolling mechanism 2 can contact the battery 20 located in the receiving space 101 on one side of the corresponding layer plate 1 and move relative to the battery 20 along the first direction X to roll the surface of the battery 20.

[0047] It should be noted that when the battery 20 is subjected to formation treatment, the battery 20 is in the process of processing and has not yet formed a final battery 20 finished product. Therefore, in addition to the main structure of the battery core, the battery 20 also includes an aluminum-plastic film wrapped outside the main structure, and the aluminum-plastic film forms an additional structure composed of a double-layer aluminum-plastic film outside the battery core (of course, the additional structure can also include other structures that do not need to be rolled). The additional structure will be removed by cutting and other methods in subsequent processing steps. The above structure is a prior art.

[0048] In order to ensure that the battery formation fixture can perform rolling processing on the main body of the battery cell without dead angle, an additional mechanism that does not require rolling processing for the battery 20 is generally provided to be connected to the limiting mechanism 3 to achieve the effect of limiting the battery 20, such as Figure 2 Alternatively, a step structure may be formed on one side of the battery 20 located in the accommodation space 101 near the second end 12, and the step structure is located on the side of the battery 20 that does not need to be rolled. The limiting mechanism 3 limits the battery 20 through the step structure.

[0049] When the battery formation fixture is in use, it is only necessary to ensure that the battery 20 is always located in the accommodation space 101 during the entire rolling process and does not exceed the rolling range of the rolling mechanism 2. At this time, there are no special requirements for the length, width, thickness and other dimensions of the battery 20. When the battery 20 is located in the above-mentioned accommodation space 101, the projection of the battery 20 in the thickness direction (also the thickness direction of the layer 1) always falls within the outer contour of the projection of the layer 1 in the thickness direction, such as Figure 4 shown.

[0050] Since the battery 20 will not move relative to the accommodating space 101 during the rolling process, it is sufficient to ensure that the projection of the side of the battery 20 facing the layer plate 1 in the thickness direction of the layer plate 1 does not exceed the side edge of the layer plate 1. Therefore, it can be applicable to batteries 20 of different sizes.

[0051] In some embodiments, a contact surface 13 is formed on one side of the layer plate 1 facing the accommodation space 101 , and the contact surface 13 is a plane; in the thickness direction of the battery 20 , the projection of the battery 20 falls within the projection outer contour of the contact surface 13 .

[0052] That is, the contact surface 13 formed on the surface of the layer plate 1 may contact the side wall of the battery 20 at the end of rolling. In order to better protect the aluminum-plastic film of the battery 20, the surface of the contact surface 13 may be coated with an insulating layer structure made of materials such as silicone or rubber.

[0053] When in use, the battery formation fixture can use the rolling mechanism 2 installed on the layer plate 1 to roll the surface of the battery 20 during formation. The operator can apply pressure to the layer plate 1, and the layer plates 1 move closer to each other under the external force. In this process, the free end of the rolling mechanism 2 can move along its moving path from the first end 11 of the layer plate 1 to the direction where the second end 12 is located (such as Figure 1 and Figure 4 As shown in the figure, the two layer plates 1 are close to each other to ensure that the rolling mechanism 2 can continuously output the rolling force to the surface of the battery 20, so as to discharge the gas located in the inner layer / interlayer of the battery 20, so that the pole piece and the diaphragm can be in close contact, so as to achieve the effect of improving the battery interface after formation, solve the problem of local lithium precipitation that may occur in the battery 20, and further improve the service life of the battery 20. In addition, compared with the solution of high negative pressure gas suction, the use of this battery formation fixture can also overcome the problem of electrolyte loss caused by high negative pressure suction technology.

[0054] It should be noted that the number of roller pressing mechanisms 2 on any layer plate 1 is several:

[0055] When the number of the rolling mechanism 2 installed on any one layer plate 1 is one, the rolling mechanisms 2 installed on the two layer plates 1 are arranged opposite to each other. Any rolling mechanism 2 is used to perform rolling processing on one side of the battery 20 in the thickness direction.

[0056] When the number of rolling mechanisms 2 installed on any layer plate 1 is two or more, the rolling mechanisms 2 installed on the two layer plates 1 can be arranged exactly opposite to each other, or can be staggered in the first direction X or in another direction orthogonal to the first direction X. It is only necessary to ensure that the several rolling mechanisms 2 located on the same layer plate 1 can perform a rolling process on the surface of the side opposite to the battery 20 without dead angles and that the rolling mechanisms 2 do not interfere with each other; alternatively, the rolling mechanisms 2 installed on the two layer plates 1 can be arranged opposite to each other one by one and perform rolling process on different batteries 20 respectively, that is, the accommodating space 101 can perform a rolling process on multiple batteries 20 at the same time and the batteries 20 are arranged one by one with the rolling mechanisms 2.

[0057] Generally speaking, the layer plates 1 of the two clamping members 10 should always remain in a relatively parallel state when rolling the battery 20 .

[0058] In some embodiments, the moving distance of the rolling mechanism 2 in the first direction X is not less than the size of the to-be-rolled area of ​​the battery 20 in the first direction X.

[0059] The area to be rolled of the battery 20 is the side wall of the main part of the battery 20 with the battery cells in the thickness direction of the battery 20. When the moving distance of the rolling mechanism 2 in the first direction X is not less than the size of the area to be rolled of the battery 20 in the first direction X, it can be ensured that the rolling mechanism 2 can perform rolling processing on the area to be rolled of the battery 20 without dead angles.

[0060] Ideally, after the battery 20 is rolled once, the gas formed in the battery 20 during the formation stage of the battery 20 can be discharged. In actual processing, the battery 20 can be rolled once or repeatedly rolled multiple times as needed to discharge as much gas as possible.

[0061] In some embodiments, the limiting mechanism 3 includes a limiting block 31 and an elastic telescopic member 32, and the limiting block 31 is installed on the layer plate 1 via the elastic telescopic member 32; when the two clamping members 10 approach each other, the limiting block 31 can be against the battery 20 located in the accommodating space 101 to fix the battery 20.

[0062] The above-mentioned limit block 31 should be made of a rigid material with a certain size, and is used to apply a certain clamping force to the battery 20 to ensure a better limiting effect on the battery 20; and the elastic telescopic member 32, in addition to being used to cooperate with the limit block 31 to provide a certain limiting force to the battery 20, can also cooperate with the rotation of the rolling mechanism 2 in a telescopic manner, so that the limit block 31 has a certain displacement, ensuring that the limit mechanism 3 can always maintain abutment and limitation on the battery 20 as the layer plate 1 approaches relatively and the rolling mechanism 2 rotates, thereby avoiding displacement of the battery 20.

[0063] Specifically, the stopper 31 is made of aluminum profile, and its outer wall is coated with an insulating layer made of any one or more materials selected from silicone, Teflon and rubber. The insulating layer can also play a certain buffering effect to prevent the stopper 31 from damaging the surface of the battery 20. The elastic expansion member 32 is made of a spring with good elasticity.

[0064] It should be noted that when the elastic telescopic member 32 is in the maximum compression state, the sum of the total length of the two relatively arranged limit blocks 31 extending into the accommodating space 101 and the thickness of the clamped battery 20 should not exceed the thickness of the main body of the battery 20 with the battery cell.

[0065] The structure of the above-mentioned rolling mechanism 2 is specifically described below:

[0066] like Figure 2 and Figure 3 As shown, the rolling mechanism 2 is rotatably mounted on the side of the layer plate 1 facing the accommodation space 101, and can abut against the battery 20 located in the accommodation space 101. When the two layer plates 1 are close to each other, the rolling mechanism 2 can roll the surface of the battery 20 and rotate toward the side of the first end 11 of the layer plate 1.

[0067] In some embodiments, the rolling mechanism 2 is rotatably mounted on the layer plate 1 via a fixed shaft 4 , and a plurality of elastic members are disposed on the outer sleeve of the fixed shaft 4 , and the elastic members apply a force to the rolling mechanism 2 to rotate in a direction away from the first end 11 .

[0068] The rolling mechanism 2 can extend toward the accommodation space 101 relative to the layer plate 1 under the action of the elastic member. When the free end of the rolling mechanism 2 contacts the surface of the battery 20 located in the accommodation space 101 and rotates toward the first end 11 under the action of the abutting force, the elastic member will deform with the rotation of the rolling mechanism 2. The elastic member in the deformed state will generate a torque or rotational force that drives the elastic member to restore its initial shape. When the external force acting on the torsion spring 41 and the rolling mechanism 2 disappears (that is, the rolling mechanism 2 is separated from the battery 20), the elastic member will restore its initial shape under the action of the above-mentioned torque or rotational force, and drive the rolling mechanism 2 back to its initial position.

[0069] In some embodiments, the elastic member is a torsion spring 41 .

[0070] The torsion spring 41 can store and release angular energy or statically fix the rolling mechanism 2 connected thereto by rotating the force arm around the central axis of the spring body. The fixed shaft 4 is inserted into the torsion spring 41 and fixedly connected to the layer plate 1 .

[0071] The connection method between the fixed shaft 4 and the layer plate 1 is prior art and will not be described in detail here.

[0072] When installing the fixed shaft 4 , it is only necessary to design the end of the relevant fixing structure not to exceed the side of the layer board 1 facing the accommodating space 101 in the thickness direction of the layer board 1 .

[0073] In some embodiments, the rolling mechanism 2 includes a connecting rod 21 and a pressure roller 22 , the two ends of the connecting rod 21 are respectively connected to the pressure roller 22 and the fixed shaft 4 , and the outer peripheral side wall of the pressure roller 22 is used to roll the surface of the battery 20 .

[0074] The connecting rod 21 can interact with the elastic member and rotate at a certain angle in a direction away from the first end 11 of the layer plate 1 under the drive of the torsion spring 41 .

[0075] Specifically, the connecting rod 21 is made of aluminum profiles and has high strength, and the pressing roller 22 is made of aluminum profiles or other conventional materials.

[0076] In some embodiments, the pressure roller 22 can rotate freely around its own axis relative to the connecting rod 21, thereby reducing the friction between the pressure roller 22 and the surface of the battery 20, and preventing the pressure roller 22 from causing wear or damage to the surface of the battery 20 or the aluminum-plastic film structure arranged on the surface of the battery 20 during the rolling process.

[0077] In order to ensure that the pressing roller 22 has a better rolling effect on the battery 20, in some embodiments, such as Figure 5 As shown, the projection length of the pressure roller 22 in the first direction X (i.e., the axial length of the pressure roller 22) is not less than the projection length of the battery 20 in the same direction and either of the two end edges of the pressure roller 22 is flush with or exceeds the side edge of the corresponding side of the battery 20.

[0078] The connecting rod 21 may be cylindrical or Figure 2 or Figure 3 The “Y”-shaped structure shown is mainly used to connect the fixed shaft 4 and the pressure roller 22 , and its shape can be any one disclosed in the prior art. This embodiment does not limit the shape of the connecting rod 21 .

[0079] In order to prevent the rolling mechanism 2 from damaging the surface of the battery 20 when in use, in some embodiments, an insulating layer is provided on the surface of the connecting rod 21 and the pressing roller 22. The insulating layer is made of a material selected from Teflon, rubber and silicone.

[0080] In order to further ensure that the pressure applied by the two clamping members 10 to the two side walls of the battery 20 in the thickness direction remains consistent, in some embodiments, part of the surface of the contact surface 13 is recessed inward to form a groove 14 for accommodating the rolling mechanism 2; when the rolling mechanism 2 rotates into the groove 14, the contact surface 13 can fit the surface of the battery 20.

[0081] When the rolling mechanism 2 rotates into the groove 14, the contact surface 13 of the layer plate 1 fits with the surface of the battery 20. In an ideal state, the two rolling mechanisms 2 arranged opposite to each other can be rotated into the groove 14 at the same time, at which time the two layer plates 1 are respectively located on both sides of the battery 20 and fit with the two side walls of the battery 20 in the thickness direction, and exert the same force on the battery 20.

[0082] The shape of the groove 14 matches the shape of the rolling mechanism 2. In addition, the size of the groove 14 should not be too large, so as to ensure that the contact surface 13 of the layer board 1 has a relatively large area as much as possible.

[0083] In some embodiments, a portion of the surface of the layer plate 1 in the second direction Y is recessed inwards and forms a mounting groove 15 for mounting the rolling mechanism 2 and / or the limiting mechanism 3, such as Figure 2-Figure 3 As shown, the mounting groove 15 is arranged adjacent to the contact surface 13 and the mounting groove 15 is communicated with the groove 14 .

[0084] The second direction Y refers to the thickness direction of the layer board 1 .

[0085] In the absence of conflict, the various features in the above embodiments may be combined with each other.

[0086] Next, the battery 20 (group A) treated by the battery formation fixture provided in this embodiment and the battery 20 (group B) not treated by the battery formation fixture provided in this embodiment were subjected to the same formation process and method, and the first charge and discharge efficiency and the cycle performance test under 1C current were performed. The comparison results are shown in the following table:

[0087] Battery ID Energy efficiency Capacity retention rate after 200 cycles Capacity retention rate after 500 cycles Group A 98.53％ 99.86％ 98.65％ Group B 96.63％ 98.91％ 96.76％

[0088] Through multiple experiments, for example, there are certain differences in the interfaces of lithium-ion batteries obtained by group A (embodiment) and group B (comparative example). After the formation is completed, by disassembling the battery 20, it is found that the interface of the negative electrode of the battery treated with the battery formation fixture is relatively flat and there is no lithium precipitation; while the interface of the battery formed without this fixture is rough and there is lithium precipitation, which seriously affects the battery performance.

[0089] The battery formation fixture is conducive to the discharge of gas from the internal layer / interlayer of the battery 20 by rolling the battery surface, so that the pole piece / diaphragm / pole piece are in close contact, the battery interface after formation is improved, and the problem of local lithium precipitation is solved. At the same time, it can be found from the above table that the battery 20 treated by the battery formation fixture has a capacity retention rate of 98.65% when the battery 20 is cycled at room temperature for 500 cycles at 1C, while the capacity retention rate of the unused battery 20 is 96.76% when the battery 20 is cycled at room temperature for 500 cycles at 1C.

[0090] It can be understood that the battery formation fixture provided in this embodiment has high applicability and can be used for the formation processing of soft-pack batteries of different sizes. It can discharge the gas formed between the battery layers by rolling without basically affecting the electrolyte, thereby achieving the effect of improving the battery interface after formation and solving the problem of local lithium precipitation, thereby improving the stability of the battery 20 and extending the service life of the battery 20.

[0091] The embodiment of the utility model further provides a formation device, which comprises any one of the battery formation fixtures described above.

[0092] The formation device can effectively improve the battery interface after formation through the battery formation fixture, and solve the problem of local lithium deposition of the battery 20.

[0093] In the absence of conflict, the features in the above embodiments may be combined with each other.

[0094] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A battery formation fixture, characterized in that: It comprises a pair of symmetrically arranged clamping members (10), any one of the clamping members (10) comprising: A layer plate (1), wherein a receiving space (101) is formed between the layer plates (1) of the two clamping members (10) arranged opposite to each other to receive a battery (20), and the layer plate (1) has a first end (11) and a second end (12) in a first direction; A rolling mechanism (2), the rolling mechanism (2) being rotatably mounted on the layer plate (1) and facing the accommodation space (101), and the rolling mechanism (2) being capable of rotating toward the position where the first end (11) is located under the driving force of an external force; A limiting mechanism (3), the limiting mechanism (3) being mounted on the layer plate (1) and being used to limit the position of the battery (20); When the two clamping members (10) are brought close to each other, the rolling mechanism (2) can contact the surface of the battery (20) located in the accommodating space (101) and move relative to the battery (20) in a first direction to roll the surface of the battery (20).

2. The battery formation fixture according to claim 1, characterized in that: The moving path of the rolling mechanism (2) in the first direction is not less than the size of the area to be rolled of the battery (20) in the first direction.

3. The battery formation fixture according to claim 1, characterized in that: The limiting mechanism (3) comprises a limiting block (31) and an elastic telescopic member (32), and the limiting block (31) is installed on the layer board (1) via the elastic telescopic member (32); When the clamping members (10) on both sides are close to each other, the limiting block (31) can abut against the battery (20) located in the accommodating space (101) to fix the battery (20).

4. The battery formation fixture according to claim 1, characterized in that: The rolling mechanism (2) is rotatably mounted on the layer plate (1) via a fixed shaft (4); a plurality of elastic members are provided on the outer sleeve of the fixed shaft (4); and the elastic members apply a force to the rolling mechanism (2) to rotate in a direction away from the first end (11).

5. The battery formation fixture according to claim 4, characterized in that: The elastic member is a torsion spring (41).

6. The battery formation fixture according to claim 4, characterized in that: The rolling mechanism (2) comprises a connecting rod (21) and a pressing roller (22), the two ends of the connecting rod (21) being respectively connected to the pressing roller (22) and the fixed shaft (4), and the outer peripheral side wall of the pressing roller (22) is used for rolling the surface of the battery (20).

7. The battery formation fixture according to any one of claims 1 to 6, characterized in that: A contact surface (13) is formed on one side of the layer plate (1) facing the accommodating space (101), and the contact surface (13) is a plane; In the thickness direction of the battery (20), the projection of the battery (20) falls within the projection outer contour of the contact surface (13).

8. The battery formation fixture according to claim 7, characterized in that: Part of the surface of the contact surface (13) is recessed inwards to form a groove (14) for accommodating the rolling mechanism (2); when the rolling mechanism (2) rotates into the groove (14), the contact surface (13) can fit the surface of the battery (20).

9. The battery formation fixture according to claim 8, characterized in that: Part of the surface of the layer plate (1) in the second direction is recessed inwards and forms a mounting groove (15) for mounting the rolling mechanism (2) and / or the limiting mechanism (3); the mounting groove (15) is arranged adjacent to the contact surface (13) and the mounting groove (15) is in communication with the groove (14).

10. A chemical formation device, characterized in that: A battery formation fixture comprising the battery formation fixture according to any one of claims 1 to 9.

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