Battery shell structure, battery and electric equipment
By setting a thinning groove on the inner wall of the battery shell, the cavity space is increased and the flatness of the tab position is improved, which solves the problem of extrusion of the tab position during the battery cycle and improves the safety and stability of the battery.
Patent Information
- Application Number
- CN202422299842.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2034-09-20
AI Technical Summary
During the use of existing battery steel shells, the battery cells expand after cycling, resulting in severe squeezing of the pole pieces at the tabs, abnormal lithium deposition, and reduced safety and stability.
A battery shell structure is designed with a thinning groove on the inner wall to increase the cavity space, and the battery cell protrusion corresponding to the tab is assembled into the thinning groove to reduce the extrusion stress of the pole piece at the tab position, reserve extrusion space, improve the flatness of the battery cell and balance the extrusion stress.
It effectively avoids the abnormal phenomenon of lithium deposition on the pole piece in the tab area, improves the cycle performance of the battery cell, and enhances the safety and stability of the battery.
Smart Images
Figure CN223414159U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and in particular relates to a battery shell structure, a battery and electrical equipment. Background Art
[0002] With the development of new energy sources, more and more fields are adopting new energy as a power source. Due to their advantages such as high energy density, rechargeability, safety and environmental protection, batteries are widely used in new energy vehicles, consumer electronics, energy storage systems and other fields. Batteries consist of a battery casing and a battery cell assembly housed within the battery casing. The battery casing protects the battery cell assembly and ensures safe use of the battery.
[0003] However, during use, some existing battery steel shells expand after the battery cell cycles, which will cause compression between the internal layers of the pole pieces. In addition, since the position of the pole ear part is relatively protruding, the pole pieces corresponding to the pole ear part are squeezed more severely, resulting in abnormal lithium deposition, which leads to cycle failure and reduces the safety and stability of use. Utility Model Content
[0004] The purpose of the utility model is to provide a battery casing structure to address the deficiencies of the existing technology and to solve the technical problems of low safety and stability in existing use.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A battery shell structure includes a shell; a placement cavity is provided in the shell; an opening is provided in the shell and is connected to the placement cavity; the inner wall surface of the shell is provided with at least one thinning groove; one end of the thinning groove extends to the opening.
[0007] Preferably, the inner wall surface includes an inner side wall and an inner bottom wall;
[0008] And the thinning groove is arranged on the inner side wall; the thinning groove extends from one end of the opening to the upper end of the inner bottom wall; and / or the thinning groove is arranged inside the inner side wall and inside the inner bottom wall.
[0009] Preferably, the number of the thinning grooves is at least two; and an angle α formed by the recessed directions of two adjacent thinning grooves and a line connecting the longitudinal axis of the shell satisfies: 90°≤α≤180°.
[0010] Preferably, the number of the thinning grooves is two;
[0011] The α=180°; and / or the α=90°.
[0012] Preferably, the relationship between the depth h1 of the thinning groove and the thickness h2 of the inner wall surface at a portion other than the thinning groove satisfies: h1<h2; and h1=(5%-50%)*h2.
[0013] Preferably, the thinning groove corresponds to the position of the battery cell tab; and the relationship between the width L1 of the thinning groove and the width L2 of the battery cell tab satisfies: L1-L2=(0.1-2) mm.
[0014] Preferably, a first guiding arc surface is provided on a side of the thinning groove facing the placement cavity; the first guiding arc surface is convexly arranged toward the placement cavity;
[0015] And / or, the thinning groove is provided with a second guide arc surface on the bottom inner wall away from the placement cavity; the second guide arc surface is recessed toward the placement cavity.
[0016] Preferably, the diameter d1 of the circle where the first guiding arc surface is located satisfies: d1 = 0.1 mm to 5 mm;
[0017] And / or, the diameter d2 of the circle where the second guide arc surface is located satisfies: d2 = 0.1 mm to 5 mm.
[0018] The utility model also discloses a battery, comprising a battery cell body and the above-mentioned battery shell structure; the battery cell body is provided with a first pole ear and a second pole ear with opposite polarities; the battery cell body is arranged in the placement cavity; the first pole ear is arranged corresponding to one of the thinning grooves; and one end of the first pole ear extends through the opening; the second pole ear is arranged corresponding to the other thinning groove; and one end of the second pole ear extends to the inner bottom of the placement cavity.
[0019] The utility model also discloses an electrical device comprising the battery.
[0020] The beneficial effect of the present invention is that the technical solution increases the space for placing the cavity by adopting a thinning groove, and the position of the thinning groove is set to correspond to the position of the battery cell pole ear, so that the battery cell protrusion corresponding to the pole ear can be assembled into the inside of the thinning groove, thereby effectively improving the flatness of the battery cell position corresponding to the pole ear, and can also achieve relatively balanced extrusion stress on the internal pole piece part after the battery cell cyclic expansion, reserve extrusion space for the corresponding pole ear position after the battery cell cyclic expansion, reduce the pole piece breakage phenomenon at the pole ear position, and effectively avoid the abnormal phenomenon of pole piece lithium deposition in the pole ear area after the cycle; and improve the cycle performance, as well as the safety and stability of use. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The following will refer to the attached Figures 1 to 5To describe the features, advantages and technical effects of exemplary embodiments of the present invention.
[0022] Figure 1 This is a schematic diagram of the overall structure of a battery housing structure according to one embodiment of the present invention;
[0023] Figure 2 A top view of a battery housing structure according to an embodiment of the present invention;
[0024] Figure 3 for Figure 2 A partial enlarged view of
[0025] Figure 4 This is a schematic diagram of the overall structure of a battery housing structure according to another embodiment of the present invention;
[0026] Figure 5 This is a schematic structural diagram of a battery according to an embodiment of the present invention;
[0027] Figure 6 FIG1 is an experimental diagram of an embodiment of the present invention.
[0028] Figure 7 FIG2 is an experimental diagram of an embodiment of the present invention.
[0029] In the figure: 1-shell; 11-inner wall; 111-inner side wall; 112-inner bottom wall; 101-placement cavity; 102-opening; 103-thinning groove; 2-first guide arc surface; 3-second guide arc surface; 4-battery cell tab; 100-battery cell body; 200-first tab; 300-second tab. DETAILED DESCRIPTION
[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.
[0031] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.
[0032] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, 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 this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or multiple situations exist. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.
[0034] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.
[0035] The following is combined with Figures 1 to 5 The present invention is further described in detail, but is not intended to limit the present invention.
[0036] like Figure 1 As shown, in one embodiment of the present invention, the battery shell structure includes a shell 1; a placement cavity 101 is provided in the shell 1; an opening 102 is provided in the shell 1 and is connected to the placement cavity 101; the inner wall surface 11 of the shell 1 is provided with at least one thinning groove 103; one end of the thinning groove 103 extends to the opening 102.
[0037] The technical solution of the present invention increases the space for placing the cavity by adopting a thinning groove, and the position of the thinning groove is set to correspond to the position of the battery cell pole ear, so that the battery cell protrusion corresponding to the pole ear can be assembled into the inside of the thinning groove, thereby effectively improving the flatness of the battery cell position corresponding to the pole ear, and can also achieve relatively balanced extrusion stress on the internal pole piece part after the battery cell cyclic expansion, reserve extrusion space for the corresponding pole ear position after the battery cell cyclic expansion, reduce the pole piece breakage phenomenon at the pole ear position, and effectively avoid the abnormal lithium deposition phenomenon of the pole piece in the pole ear area after the cycle; and improve the cycle performance, as well as the safety and stability of use.
[0038] Specifically, in some embodiments, Figure 1 and 4 As shown, the inner wall surface 11 includes an inner side wall 111 and an inner bottom wall 112; and the thinning groove 103 is provided on the inner side wall 111. The inner side wall 111 may be an arc surface; the inner side wall 111 and the inner bottom wall 112 are integrally formed. In some embodiments, such as Figure 1 As shown, the end of the thinning groove 103 away from the opening 102 extends to the upper end of the inner bottom wall 112; this structure ensures that one end of the thinning groove 103 extends to the inner bottom wall 112, thereby ensuring that one tab portion can stably extend to the opening 103 and the other tab portion can stably extend to the inner bottom wall 112, thereby improving safety and stability in use. In other embodiments, such as Figure 4 As shown, the thinning groove is provided inside the inner side wall and the inner bottom wall. That is, one end of the thinning groove 103 extends to the upper surface of the inner bottom wall 112. This structure, by extending one end of the thinning groove 103 to the upper surface of the inner bottom wall 112, ensures that the other tab portion can be assembled into the thinning groove 103 of the inner bottom wall 112, thereby achieving the effect of buffering the extrusion stress in the horizontal and vertical directions, thereby improving the safety and stability of use.
[0039] Specifically, in some embodiments, Figure 1 and 2 As shown in FIG4 , there are at least two thinning grooves 103 ; each groove is used to receive a corresponding battery cell tab 4 ; and the angle α formed by the recessed directions of two adjacent thinning grooves 103 satisfies the following: 90°≤α≤180°. In other words, to reduce interference or contact between the two battery cell tabs 4 and thus cause a short circuit, the two battery cell tabs 4 need to be relatively dispersed, thereby improving safety and stability.
[0040] Among them, in some embodiments, such as Figure 1 and 2 As shown, there are two thinning grooves 103, and the angle α formed between the two thinning grooves 103 and the line connecting the longitudinal axis of the housing 1 is 180°. In other words, a double thinning groove structure 103 with an angle of 180° is formed inside the housing 1. By locally thinning the two symmetrically arranged thinning grooves 103, abnormal lithium deposition in the electrode tab area can be reduced or even avoided, improving the cycling performance of the battery cell and enhancing the safety and stability of use.
[0041] Wherein, in other embodiments, as Figure 1 and 2As shown, there are two thinning grooves 103, and the angle α formed by the two thinning grooves 103 is 90°. In other words, a double thinning groove 103 structure with a 90° angle is formed inside the housing 1. The localized thinning of the two thinning grooves 103 at right angles can reduce or even prevent abnormal lithium deposition in the electrode tab area, improving the cycling performance of the battery cell and enhancing the safety and stability of use.
[0042] Specifically, in some embodiments, Figure 4 As shown, the relationship between the depth h1 of the thinning groove 103 and the thickness h2 of the inner wall surface 11 at the non-thinning groove 103 portion satisfies: h1 < h2; and h1 = (5% to 50%) * h2. In other words, the shell wall thickness at the thinning groove 103 / the shell wall thickness at the main body = 50% to 95%. This structure maximizes the space for accommodating the cavity 101 while ensuring the structural stability of the shell 1 and the safety and stability of the battery cell.
[0043] Specifically, in some embodiments, Figure 4 As shown, the thinning groove 103 corresponds to the position of the battery cell tab 4; and the relationship between the width L1 of the thinning groove 103 and the width L2 of the battery cell tab 4 satisfies: L1-L2=(0.1-2) mm. In other words, the relatively large thinning groove 103 ensures the assembly of the battery cell tab 4 and reduces the compressive stress between the battery cell tab 4 and the housing 1, thereby improving safety and stability.
[0044] Specifically, in some embodiments, Figure 2 and 3 As shown, the thinning groove 103 is provided with a first guide arc surface 2 on the side facing the placement cavity 101; the first guide arc surface 2 is provided protruding toward the placement cavity 101. In other words, the first guide arc surface 2 with rounded corners is provided at the junction of the side wall at the exit of the thinning groove 103 and the main body of the shell 1, which can reduce the friction damage between the battery cell tab 4 and the main body of the shell 1, thereby improving the stability of the assembly. Figure 3 As shown, the diameter d1 of the circle where the first guiding arc surface 2 is located satisfies: d1 = 0.1 mm to 5 mm.
[0045] Specifically, in some embodiments, Figure 2 and 3As shown, the thinning groove 103 is provided with a second guide arc surface 3 on the bottom inner wall away from the placement cavity 101; the second guide arc surface 3 is recessed toward the placement cavity 101. In other words, the second guide arc surface 3 with rounded corners is provided at the junction of the inner bottom side wall of the thinning groove 103 and the main body of the shell 1, which can reduce the contact area between the battery cell tab 4 and the main body of the shell 1, thereby reducing friction damage between them and improving the stability of the assembly. Figure 3 As shown, the diameter d2 of the circle where the second guide arc surface 3 is located satisfies: d2 = 0.1 mm ~ 5 mm.
[0046] The utility model also provides a battery, such as Figure 5 As shown, the battery includes a cell body 100 and a battery housing structure; the cell body 100 is provided with a first tab 200 and a second tab 300 of opposite polarity; the cell body 100 is disposed within the placement cavity 101; the first tab 200 is disposed corresponding to one of the thinning grooves 103; and at least a portion of the side end of the first tab 200 is disposed within the thinning groove 103; one end of the first tab 200 is disposed corresponding to the opening 102; at least a portion of the side end of the second tab 300 is disposed in another thinning groove 103; and one end of the second tab 300 extends to the inner bottom of the placement cavity 101. The specific structure of the battery housing structure refers to the above-mentioned embodiments. Since this battery adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, and will not be described in detail here.
[0047] The first electrode tab 200 may be one of the positive electrode tab and the negative electrode tab; the second electrode tab 300 may be the other of the positive electrode tab and the negative electrode tab; and the cell electrode tab 4 may be the first electrode tab 200 or the second electrode tab 300.
[0048] Among them, after using the battery shell structure with thinning grooves, the battery with the battery shell structure and the battery without the battery shell structure (i.e., ordinary batteries) were cycled to 800 cycles at 25°C. The capacity retention rate of the two types of battery experimental groups was tested. Therefore, the experimental results are shown in Experimental Chart 1 (Cycle Capacity Retention Curve). Further, in Experimental Chart 1, green represents a conventional shell, brown represents the experimental group of the battery shell structure with thinning grooves; red represents the marked value of the cycle capacity; the horizontal axis represents the number of battery cell winding cycles; and the vertical axis represents the capacity retention rate.
[0049] Among them, after using the battery shell structure with thinning grooves, the battery with the battery shell structure and the battery without the battery shell structure (i.e., ordinary batteries) were cycled to 800 cycles at 40°C. The capacity retention rate of the two types of battery experimental groups was tested. Therefore, the experimental results are shown in Experimental Chart 2 (Cycle Capacity Retention Curve). Further, in Experimental Chart 2, green represents a conventional shell, brown represents the experimental group of the battery shell structure with thinning grooves; red represents the marked value of the cycle capacity; the horizontal axis represents the number of battery cell winding cycles; and the vertical axis represents the capacity retention rate.
[0050] Conclusion: After the tab position in the battery shell structure is thinned, the capacity retention rate of the battery cell at 25°C is increased by about 4% when it is cycled to 800 cycles; the capacity retention rate of the battery cell at 45°C is significantly improved when it is cycled to 500 cycles.
[0051] The battery cell body 100 comprises a positive electrode sheet, a negative electrode sheet, and a separator. Battery cells primarily operate by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer, which is coated on the surface of the positive electrode collector. The positive electrode collector comprises a positive electrode coating region and a positive electrode tab connected to the positive electrode coating region. The positive electrode coating region is coated with the positive electrode active material layer, while the positive electrode tab is not coated with the positive electrode active material layer. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material layer comprises a positive electrode active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer, which is coated on the surface of the negative electrode collector. The negative electrode current collector comprises a negative electrode coating region and a negative electrode tab connected to the negative electrode coating region. The negative electrode coating region is coated with the negative electrode active material layer, while the negative electrode tab is not coated with the negative electrode active material layer. The negative electrode current collector may be made of copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon or silicon, etc. The separator may be made of PP (polypropylene) or PE (polyethylene), etc.
[0052] The present utility model also proposes an electrical device, which includes a battery. The specific structure of the battery refers to the above embodiments. Since the electrical device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.
[0053] Among them, electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.; spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.; electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.
[0054] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
[0055] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation on the present invention.
Claims
1. A battery housing structure, characterized in that: It comprises a shell; a placement cavity is provided in the shell; an opening is provided in the shell and is connected to the placement cavity; the inner wall surface of the shell is provided with at least one thinning groove; one end of the thinning groove extends to the opening.
2. The battery housing structure according to claim 1, characterized in that: The inner wall surface includes an inner side wall and an inner bottom wall; The thinning groove is arranged on the inner side wall, and the thinning groove extends from one end of the opening to the upper end of the inner bottom wall; and / or, the thinning groove is arranged inside the inner side wall and inside the inner bottom wall.
3. The battery housing structure according to claim 1, wherein: The number of the thinning grooves is at least two; and an angle α formed by the concave directions of two adjacent thinning grooves and a line connecting the longitudinal axis of the shell satisfies: 90°≤α≤180°.
4. The battery housing structure according to claim 3, characterized in that: The number of the thinning grooves is two; The α=180°; and / or the α=90°.
5. The battery housing structure according to claim 1, 3 or 4, characterized in that: The relationship between the depth h1 of the thinning groove and the thickness h2 of the inner wall surface at a portion other than the thinning groove satisfies: h1<h2; and h1=(5% to 50%)*h2.
6. The battery housing structure according to claim 1, 3 or 4, characterized in that: The thinning groove corresponds to the position of the battery cell tab; and the relationship between the width L1 of the thinning groove and the width L2 of the battery cell tab satisfies: L1-L2=(0.1-2) mm.
7. The battery housing structure according to claim 1, characterized in that: A first guiding arc surface is provided on a side of the thinning groove facing the placement cavity; the first guiding arc surface is convexly arranged toward the placement cavity; And / or, the thinning groove is provided with a second guide arc surface on the bottom inner wall away from the placement cavity; the second guide arc surface is recessed toward the placement cavity.
8. The battery housing structure according to claim 7, characterized in that: The diameter d1 of the circle where the first guide arc surface is located satisfies: d1 = 0.1 mm to 5 mm; And / or, the diameter d2 of the circle where the second guide arc surface is located satisfies: d2 = 0.1 mm to 5 mm.
9. A battery, characterized in that: It comprises a battery cell body and a battery casing structure as described in any one of claims 1 to 8 above; the battery cell body is provided with a first pole tab and a second pole tab with opposite polarities; the battery cell body is arranged in the placement cavity; the first pole tab is arranged corresponding to one of the thinning grooves; and one end of the first pole tab extends through the opening; the second pole tab is arranged corresponding to the other thinning groove; and one end of the second pole tab extends to the inner bottom of the placement cavity.
10. An electrical device, characterized in that: A battery comprising the battery of claim 9.