Flexible battery

Abstract

The utility model belongs to battery technical field discloses a kind of flexible battery.The flexible battery includes shell, shell has encapsulation inner cavity, encapsulation inner cavity is used to place electrode assembly, at least part of the outer surface of shell is defined to form bending part, flexible battery can bend in bending part, and recessed lines are provided on bending part and penetrate the opposite sides of shell.The flexible battery can be bent at bending part, so that it can be shaped as needed, so that it can adapt to external space environment and adjust shape.In addition, due to the provision of recessed lines, the recessed lines can effectively guide the stress that can be dispersed when bending, so that the stress is no longer limited to a small area, the stress concentration of the bending part can be reduced to some extent, the stress of the bending part is avoided to exceed its bearing limit, so that the mechanical toughness of the battery at the bending part can be effectively enhanced, the risk of cracking or damage of the flexible battery when bending is greatly reduced, and the use safety and stability and service life of the battery are improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a flexible battery. Background Technology

[0002] With the rapid development of the robotics industry, higher demands are being placed on lithium battery technology suitable for robots. Currently, lithium batteries used in robots generally employ pouch cells or customized irregularly shaped batteries. Pouch cells, typically made of aluminum-plastic film, can be shaped as needed, making them suitable for space-constrained applications and widely used in robots. However, pouch cells have lower mechanical strength, are susceptible to punctures, and have a shorter lifespan. Customized irregularly shaped batteries are more difficult to manufacture, have higher processing costs, and are difficult to mass-produce.

[0003] To overcome the aforementioned shortcomings, existing technologies provide a flexible battery that improves overall flexibility by incorporating a rubber layer within the encapsulation shell, thereby enhancing the deformation compatibility between the flexible battery and external components. Furthermore, the encapsulation shell is less prone to damage during use, improving the stability and safety of the flexible battery. However, this flexible battery still suffers from rubber layer aging during long-term use, leading to decreased flexibility. Moreover, it fails to address the stress concentration that occurs on the encapsulation shell during deformation and bending, causing damage to the battery casing and thus compromising the battery's safety and stability during long-term use.

[0004] Therefore, a flexible battery needs to be designed to solve the problems existing in the current technology. Utility Model Content

[0005] The purpose of this invention is to provide a flexible battery that can solve the technical problem that excessive stress concentration on the encapsulation shell of existing flexible batteries during long-term use leads to damage to the encapsulation shell, thereby affecting the safe use of the flexible battery.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A flexible battery includes a housing having an encapsulation cavity for housing an electrode assembly, at least a portion of the outer surface of the housing defining a bend, the flexible battery being bendable at the bend, and the bend having recessed grooves extending through opposite sides of the housing.

[0008] Preferably, along the axial direction of the housing, the bent portion has multiple recessed textures arranged side by side and spaced apart.

[0009] Preferably, the cross-sectional shape of the recessed texture is corrugated; and / or, the cross-sectional shape of the recessed texture is straight; and / or, the cross-sectional shape of the recessed texture is honeycomb-like.

[0010] Preferably, the cross-sectional shape of the recessed textures is wavy; and / or, the waveform characteristics of multiple recessed textures are the same.

[0011] Preferably, the depth of the recessed texture is d, and the thickness of the shell at the bending part is D. The relationship between d and D is: 0.05≤d / D≤0.15.

[0012] Preferably, the width of the recessed texture is w, where 2mm ≤ w ≤ 10mm.

[0013] Preferably, each of the recessed textures includes at least one crest and at least one trough. Along the length extension direction of the recessed texture, the distance between adjacent crests and troughs is a, and the length of the recessed texture is b. The relationship between a and b is: 0.4 ≤ a / b ≤ 0.6.

[0014] Preferably, the flexible battery further includes a toughening layer, which is filled within the recessed texture.

[0015] Preferably, the housing is made of a flexible material, and the bending portion is formed on a large surface area of ​​the housing.

[0016] Preferably, the flexible battery is a blade battery or a square battery, and the housing includes two first surfaces and two second surfaces. The two first surfaces are connected by the two second surfaces to enclose and form the encapsulation cavity. The surface area of ​​the first surface is larger than the surface area of ​​the second surface, and the first surface is set as the bending portion.

[0017] Alternatively, the flexible battery is a cylindrical battery, the housing includes a cylindrical sidewall and a bottom protective plate, the cylindrical sidewall has the encapsulation cavity inside, the bottom protective plate is sealed at the open end of the cylindrical sidewall, the surface area of ​​the cylindrical sidewall is larger than the surface area of ​​the bottom protective plate, and the cylindrical sidewall is configured as the bent portion.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: Since the flexible battery provided by this utility model is provided with recessed texture, and the recessed texture can effectively guide and disperse the stress during bending, the stress is no longer limited to a small area. It can reduce the stress concentration at the bending part to a certain extent and prevent the stress at the bending part from exceeding its bearing limit. This can effectively enhance the mechanical toughness of the battery at the bending part, greatly reduce the risk of cracking or breaking when the flexible battery is bent, and improve the safety, stability and service life of the battery. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the flexible battery provided in this embodiment of the utility model;

[0020] Figure 2 This is an exploded view of the flexible battery provided in an embodiment of this utility model;

[0021] Figure 3 This is a front view of the flexible battery provided in an embodiment of the present invention;

[0022] Figure 4 This is a top view of the flexible battery provided in an embodiment of the present invention;

[0023] Figure 5 It is along Figure 4 Cross-sectional view at point AA;

[0024] Figure 6 yes Figure 5 A magnified view of a section at point B in the middle.

[0025] In the picture:

[0026] 1. Housing; 101. Recessed texture; 1011. Crest; 1012. Trough; 11. Encapsulation cavity; 12. First surface; 13. Second surface;

[0027] 2. Top cover plate; 21. Conductive terminal. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0029] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0032] The technical solution provided by this utility model will be described below with reference to the accompanying drawings and specific embodiments.

[0033] Combination Figures 1 to 6 As shown, this embodiment provides a flexible battery, which includes a housing 1, a top cover 2, and an electrode assembly. The housing 1 has an encapsulated cavity 11 for housing the electrode assembly. The top cover 2 seals the opening of the housing 1, isolating the encapsulated cavity 11 from the external environment to ensure the safety of the electrode assembly. The top cover 2 has conductive terminals 21 for conductive connection with the electrode assembly, thereby enabling the flexible battery to charge and discharge. In this embodiment, at least a portion of the outer surface of the housing 1 defines a bending portion. This bending portion allows the flexible battery to bend and deform at the bending point, allowing it to be shaped as needed and adapt to the external environment.

[0034] It should be noted that when a flexible battery is bent and deformed at the bend, if the surface of the bend is relatively flat, there will be a significant stress concentration at the bend. Moreover, as the bending radius of the flexible battery gradually increases, the stress concentration at the bend will become more and more obvious, making it very easy for the local stress at the bend to exceed its bearing limit. When the stress at the bend exceeds its bearing limit, the risk of the casing 1 cracking or breaking will increase significantly. This will not only lead to electrolyte leakage, but also cause thermal runaway of the internal electrode components, resulting in fire or explosion, seriously affecting the safety of the flexible battery.

[0035] Based on this, in order to solve the above-mentioned technical defects, the flexible battery provided in this embodiment is further provided with recessed textures 101 that run through the opposite sides of the shell 1 on the bending part. The recessed textures 101 can effectively guide and disperse the stress during bending, so that the stress is no longer limited to a small area. This can reduce the stress concentration at the bending part to a certain extent and prevent the stress at the bending part from exceeding its bearing limit. This can effectively enhance the mechanical toughness of the battery at the bending part, greatly reduce the risk of cracking or breaking when the flexible battery is bent, and improve the safety, stability and service life of the battery.

[0036] In this embodiment, the housing 1 of the flexible battery is made of a flexible material, so that the bending portion can be formed on a large surface area of ​​the housing 1 to meet the requirements of greater degree and wider range of bending deformation in actual application scenarios. For example, the housing 1 is made of materials such as nickel-titanium alloy, aluminum alloy, and magnesium alloy. Preferably, in this embodiment, the housing 1 is made of nickel-titanium alloy. When this housing 1 is processed and formed, the material is in the austenitic phase, which is easy to process and has high processing accuracy. Furthermore, the dimensions of the formed housing 1 are relatively stable, which is beneficial for assembling the electrode assembly into the mounting cavity or assembling multiple flexible batteries in groups. After the flexible battery is encapsulated, the housing 1 is in the martensitic phase during use. At this time, the housing 1 softens and exhibits flexibility, thus adapting to the external space environment and adjusting its shape.

[0037] Specifically, the processing steps of the housing 1 can be summarized as follows:

[0038] S1. The flexible metal material is heated to a temperature higher than A_F (the temperature at which the austenite phase transformation is completed) by high-frequency heating or tunnel furnace.

[0039] S2. The mold has a built-in heating coil to raise the mold temperature to a level higher than the material A_F temperature;

[0040] S3. The material enters the mold cavity and is stamped, stretched, and sheared to form the shape.

[0041] S4. The formed shell 1 and top cover plate 2 are encapsulated into a flexible battery;

[0042] S5. The flexible battery can be cooled to a temperature below the M_F temperature, and its shape can be adjusted according to the external space.

[0043] Understandably, in order to accommodate the bending and deformation requirements of flexible batteries, in this embodiment, the battery anode, battery cathode, and separator in the electrode assembly are all made of flexible materials that can be bent and deformed. Referring to existing technologies, the battery anode and battery cathode can be made of metal foil, such as copper foil, aluminum foil, nickel foil, silver foil, titanium foil, etc. The separator can be made of resin film, such as polypropylene film, polyethylene film, polyimide film, polyester film, etc.

[0044] The outer shape of the flexible battery casing 1 can be manufactured according to usage requirements. For example, in this embodiment, the flexible battery is a square battery. Figure 2 As shown, the housing 1 includes two first surfaces 12 and two second surfaces 13. The two first surfaces 12 are connected by the two second surfaces 13, thereby forming the encapsulation cavity 11 by the two first surfaces 12 and the two second surfaces 13. The surface area of ​​the first surface 12 is larger than the surface area of ​​the second surface 13, meaning that the first surface 12 mainly plays a role in bending and deformation within the housing 1, thus forming the bending portion. In this way, the flexible battery can be bent at each of the two first surfaces 12 to adapt to more complex application scenarios.

[0045] Of course, in other parallel embodiments, when the flexible battery is a blade battery, the above-mentioned housing 1 is also applicable. The housing 1 only changes in its external shape, that is, the external shape of the housing 1 changes to a blade shape or a long and flat shape.

[0046] It should be noted that in other parallel embodiments, the flexible battery can also be a cylindrical battery. When it is a cylindrical battery, the housing 1 includes a cylindrical sidewall and a bottom protective plate. The cylindrical sidewall has an encapsulation cavity 11, and the bottom protective plate and top cover plate 2 are respectively sealed at the two open ends of the cylindrical sidewall to seal the electrode assembly in the encapsulation cavity 11. Furthermore, since the surface area of ​​the cylindrical sidewall is larger than that of the bottom protective plate, this embodiment sets the cylindrical sidewall as the bending portion. Through the above configuration, the housing 1 of the cylindrical flexible battery also possesses flexible characteristics, allowing it to be bent along the axial direction of the housing 1, so that its shape can be adaptively adjusted according to the external operating environment.

[0047] The following is combined Figures 1 to 3 The recessed texture 101 provided in this embodiment will be analyzed and described in detail.

[0048] refer to Figure 3 As shown, in this embodiment, along the axial direction of housing 1 (reference) Figure 3 (Y) The first surface 12 of the housing 1 has multiple recessed textures 101 arranged side by side and spaced apart. By appropriately arranging multiple recessed textures 101 on the first surface 12, when the flexible battery is bent and deformed, the stress of the housing 1 will be concentrated in the area of ​​the recessed textures 101, making the overall deformation of the housing 1 more uniform and stable, and the stress dispersion effect more obvious, thus avoiding the situation where the local stress concentration on the first surface 12 is too large and causes cracking.

[0049] Optionally, in this embodiment, the flexible battery further includes a toughening layer. The toughening layer is filled and disposed in the recessed texture 101. The toughening layer is preferably made of glass fiber material, which has good tensile properties. The toughening layer can greatly enhance the flexibility of the entire shell 1, prevent the shell 1 from easily breaking when bent and deformed, improve the service life of the shell 1, and also ensure that the bending and deformation process of the shell 1 is smoother.

[0050] Furthermore, in this embodiment, the cross-sectional shape of the recessed textures 101 is wavy, and the waveform characteristics (i.e., the wavelength, peak value, and trough value of each recessed texture 101) are the same. Through the curved structure of the waveform, the stress acting on the shell 1 can be more evenly distributed when the shell 1 bends and deforms. The shape of the waveform allows the stress to be distributed along the curve, avoiding stress concentration at a single point, thereby effectively enhancing the shell 1's resistance to cracking and improving its fracture resistance.

[0051] Of course, in other parallel embodiments, the cross-sectional shape of the recessed texture 101 can also be straight or honeycomb-shaped. The above-mentioned configurations can effectively disperse pressure when the shell 1 deforms, thereby reducing local stress concentration. Furthermore, when the recessed texture 101 is designed as a straight line, the manufacturing process is simpler, and production costs can be controlled to some extent. When the recessed texture 101 is designed as a honeycomb, stress is evenly distributed along multiple channels and surfaces of the honeycomb. Each honeycomb unit can independently bear a portion of the stress, and due to the high symmetry of the honeycomb shape, it is more conducive to dispersing stress throughout the entire recessed texture 101, thereby improving crack resistance and load-bearing capacity. Therefore, those skilled in the art can select the shape of the recessed texture 101 according to actual needs, and this utility model does not limit this.

[0052] It should be noted that in other parallel embodiments, the cross-sectional shapes of multiple recessed patterns 101 on the same first surface 12 can all be the same; alternatively, at least two recessed patterns 101 can be set with different cross-sectional shapes. For example, on a first surface 12, any two of the three types of recessed patterns 101—wavy, straight, and honeycomb—can exist simultaneously; or, on a first surface 12, all three types of recessed patterns 101—wavy, straight, and honeycomb—can exist simultaneously. According to simulation data, as the types of recessed patterns 101 on the first surface 12 gradually increase within a certain range, although the molding difficulty gradually increases, it becomes more suitable for the needs of high dynamic bending. That is, the flexible battery can be bent simultaneously along the axis of the shell 1 and twisted around the axis of the shell 1, thereby making the application range of the flexible battery wider and its adaptability to deformation better.

[0053] More specifically, in this embodiment, in order to ensure better stress dispersion when the recessed texture 101 is wavy, the manufacturing dimensions of the recessed texture 101 are further optimized.

[0054] In this embodiment, reference Figure 4 , Figure 5 and Figure 6 As shown, the depth of the recessed texture 101 is set as d, and the thickness of the first surface 12 located at the bend in the shell 1 is set as D. The relationship between d and D is: 0.05 ≤ d / D ≤ 0.15. For example, the ratio between the depth of the recessed texture 101 and the thickness of the first surface 12 can be 0.05, 0.07, 0.05, 0.11, 0.13, 0.15, etc. It should be noted that when the ratio between the two exceeds 0.15, the depth of the recessed texture 101 will be too large, which is not conducive to processing and manufacturing, and will also affect the structural strength of the area near the recessed texture 101 on the shell 1. When the ratio between the two is less than 0.05, the depth of the recessed texture 101 will be insufficient and unable to effectively disperse external stress, thus failing to achieve the expected effect of reducing stress concentration.

[0055] For example, the thickness D of the first housing 1 provided in this embodiment is 0.5 mm, and the depth d of the recessed texture 101 is between 0.025 mm and 0.075 mm.

[0056] In this embodiment, reference Figure 3As shown, the width of the recessed texture 101 is set to w, where w satisfies: 2mm ≤ w ≤ 10mm. For example, the width of the recessed texture 101 can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc. If the width of the recessed texture 101 is less than 2mm, it will result in the recessed texture 101 being too narrow, making it difficult to stamp and form with a mold, and the forming accuracy will be difficult to control precisely. If the width of the recessed texture 101 is greater than 10mm, it will increase the cost of mold manufacturing and debugging, increase the processing difficulty, and a wider recessed texture 101 may make the surface shape change too gradual, resulting in an inability to effectively disperse stress, thus weakening the effect of dispersing external stress.

[0057] In this embodiment, we continue to refer to Figure 3 As shown, taking a single recessed texture 101 as an example, the single recessed texture 101 includes at least one crest portion 1011 and at least one trough portion 1012. Along the length extension direction of the recessed texture 101, the distance between adjacent crest portions 1011 and trough portions 1012 is a, and the length of the recessed texture 101 is b. The relationship between a and b is: 0.4 ≤ a / b ≤ 0.6. For example, the ratio between the two can be 0.4, 0.45, 0.5, 0.55, 0.6, etc.

[0058] It should be noted that if a / b is less than 0.4, the short distance between the crests 1011 and troughs 1012 will lead to stress concentration in local areas, which may cause the shell 1 to experience early fatigue or fracture at the recessed texture 101 during bending deformation. Moreover, a small a / b ratio will directly increase the processing accuracy requirements of the mold, thereby affecting the molding quality and efficiency of the shell 1. If a / b is greater than 0.6, it indicates that the distance between the crests 1011 and troughs 1012 becomes too long, the structure of the recessed texture 101 becomes sparser, and the distribution of the crests 1011 and troughs 1012 is no longer uniform, thus weakening the stress dispersion function of the recessed texture 101.

[0059] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A flexible battery, characterized in that, Includes a housing (1) having an encapsulation cavity (11) for placing an electrode assembly, at least a portion of the outer surface of the housing (1) defining a bend, the flexible battery being bendable at the bend, and the bend having recessed textures (101) extending through opposite sides of the housing (1).

2. The flexible battery according to claim 1, characterized in that, Along the axial direction of the housing (1), a plurality of recessed textures (101) are arranged side by side and spaced apart on the bent portion.

3. The flexible battery according to claim 2, characterized in that, The cross-sectional shape of the recessed texture (101) is wavy; and / or, the cross-sectional shape of the recessed texture (101) is straight; and / or, the cross-sectional shape of the recessed texture (101) is honeycomb.

4. The flexible battery according to claim 3, characterized in that, The cross-sectional shape of the recessed texture (101) is wavy; and / or, the waveform characteristics of multiple recessed textures (101) are the same.

5. The flexible battery according to claim 4, characterized in that, The depth of the recessed texture (101) is d, and the thickness of the shell (1) at the bending part is D. The relationship between d and D is: 0.05≤d / D≤0.

15.

6. The flexible battery according to claim 4, characterized in that, The width of the recessed texture (101) is w, where 2mm ≤ w ≤ 10mm.

7. The flexible battery according to claim 4, characterized in that, Each of the recessed textures (101) includes at least one crest (1011) and at least one trough (1012). Along the length extension direction of the recessed texture (101), the distance between adjacent crests (1011) and troughs (1012) is a, and the length of the recessed texture (101) is b. The relationship between a and b is: 0.4≤a / b≤0.

6.

8. The flexible battery according to claim 1, characterized in that, The flexible battery also includes a toughening layer, which is filled within the recessed texture (101).

9. The flexible battery according to any one of claims 1-8, characterized in that, The shell (1) is made of a flexible material, and the bending part is formed on the large surface area of ​​the shell (1).

10. The flexible battery according to claim 9, characterized in that, The flexible battery is a blade battery or a square battery. The housing (1) includes two first surfaces (12) and two second surfaces (13). The two first surfaces (12) are connected by the two second surfaces (13) to enclose and form the encapsulation cavity (11). The surface area of ​​the first surface (12) is larger than the surface area of ​​the second surface (13), and the first surface (12) is set as the bending part. Alternatively, the flexible battery is a cylindrical battery, the housing (1) includes a cylindrical sidewall and a bottom protective plate, the cylindrical sidewall has the encapsulation cavity (11) inside, the bottom protective plate is sealed at the opening end of the cylindrical sidewall, the surface area of ​​the cylindrical sidewall is greater than the surface area of ​​the bottom protective plate, and the cylindrical sidewall is configured as the bent portion.

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