Battery

Abstract

The utility model relates to the technical field of batteries, in particular to a battery. The battery core coating film comprises a film body which is provided with two film bodies opposite to the two side surfaces of a battery core in the thickness direction respectively; the supporting assembly is arranged on the surface, facing the battery cell, of the membrane body, the supporting assembly comprises a supporting piece and an elastic telescopic piece, the supporting piece comprises a central area and an edge area surrounding the central area, the central area is connected with the membrane body, and a gap is formed between the edge area and the membrane body; the elastic telescopic piece is arranged in a gap between the edge area and the membrane body, and the two ends of the elastic telescopic piece are connected with the membrane body and the supporting piece respectively. According to the battery disclosed by the utility model, the positive plate and the negative plate of the battery cell are stably attached through the supporting assembly, so that the service life of the battery is prolonged, and the satisfaction degree of a user is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery. BACKGROUND

[0002] In the prior art, the edge region of the negative electrode sheet usually covers the positive electrode sheet region due to the design of battery performance, and in the processing process, the edge of the electrode sheet where the tab is arranged is covered due to the "trailing" effect during coating, or the active material layer near the two side tabs shrinks to the middle under the action of surface tension during the drying process, resulting in edge thinning effect, causing the part of the battery cell to have obvious thickness difference relative to the whole battery cell.

[0003] During the charging and discharging process of the battery, the battery cell expands and shrinks. During long-term cycle use, the position with uneven thickness on the battery cell gradually weakens the adhesion between the positive electrode sheet and the negative electrode sheet at the corresponding position due to uneven stress, and the interface contact gradually deteriorates, resulting in edge lithium precipitation on the four sides, affecting the cycle life and safety performance of the battery. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a battery, which applies supporting force to both sides of the thickness of the battery cell to ensure good adhesion between the positive electrode sheet and the negative electrode sheet of the battery cell.

[0005] The embodiment of the utility model provides a kind of battery, comprising: battery cell;Battery cell covering film, comprising: film body, is equipped with two film bodies respectively with the two sides surface of the thickness direction of the battery cell is opposite;Supporting assembly is set to the surface of the film body towards the battery cell, and the supporting assembly includes: support piece, the support piece includes center area and edge region around the center area, the center area is connected with the film body, and the gap is formed between the edge region and the film body;Elastic telescopic piece is arranged in the gap between the edge region and the film body, and the both ends of the elastic telescopic piece are respectively connected with the film body and the support piece.

[0006] The utility model discloses a battery, the positive plate and the negative plate of the battery can be kept in the state of sticking together continuously, and the interface contact is avoided from deteriorating to cause lithium precipitation, which is favorable for prolonging the service life of the battery, thereby improving the satisfaction of the user.

[0007] According to some embodiments of the utility model, the thickness T of the support satisfies 0.1mm≤T≤3mm.

[0008] According to some embodiments of the utility model, the battery further comprises a shell, the shell is provided with a containing cavity, the battery core and the battery core coating film are arranged in the containing cavity, the number of the battery core is N, the size of the containing cavity along the thickness direction of the battery core is D, the thickness of the battery core is t, and the thickness of the film body is d, wherein the D, the t and the d satisfy 0.5≤T(D-2d) / Nt≤5.

[0009] According to some embodiments of the utility model, the distance Lw between the opposite ends of the support along the width direction of the battery core and the width Wa of the negative plate of the battery core satisfy Lw≤Wa; and / or, the distance Hh between the opposite ends of the support along the length direction of the battery core and the distance Ha between the opposite ends of the negative plate along the length direction of the battery core satisfy Hh≤Ha.

[0010] According to some embodiments of the utility model, the arc length L of the cross section of the support along the width direction of the battery core, the distance Wc between the opposite ends of the positive plate of the battery core along the width direction of the battery core and the distance Wa between the opposite ends of the negative plate of the battery core along the width direction of the battery core satisfy Wc≤L≤Wa; and / or,

[0011] The arc length H of the support along the length direction of the battery core, the distance Hc between the opposite ends of the positive plate along the length direction of the battery core and the distance Ha between the opposite ends of the negative plate along the length direction of the battery core satisfy Hc≤H≤Ha.

[0012] In some embodiments, the gap between the edge region and the film body gradually increases in a direction from the center region to the edge region.

[0013] According to some embodiments of the present application, the plurality of elastic stretchers are evenly spaced along the circumference of the support.

[0014] According to some embodiments of the present application, the plurality of elastic stretchers are evenly spaced along the circumference of the support.

[0015] According to some embodiments of the present application, the edge region has a first side connected to the center region and a second side away from the center region, the distance between the second side and the film body is h, the length of the elastic stretchers is L1, and the L1 and the h satisfy: 0.5h≤L1≤h.

[0016] According to some embodiments of the present application, the support is provided with a ventilation structure. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and serve to explain the principles of the application together with the description.

[0018] Figure 1 A structural schematic diagram of a battery according to an embodiment of the present application;

[0019] Figure 2 An unfolded structural schematic diagram of a cell cladding film according to an embodiment of the present application;

[0020] Figure 3 One of the folding state diagrams of a cell cladding film cladding a cell according to an embodiment of the present application;

[0021] Figure 4 The second folding state diagram of a cell cladding film cladding a cell according to an embodiment of the present application;

[0022] Figure 5 The state diagram of a cell cladding film cladding a cell according to an embodiment of the present application;

[0023] Figure 6 The gap between the edge region and the film body of the support of a cell cladding film cladding a cell according to an embodiment of the present application;

[0024] Figure 7 The distribution state diagram of an elastic stretcher according to an embodiment of the present application;

[0025] Figure 8 The distribution state diagram of an elastic stretcher according to another embodiment of the present application.

[0026] Reference Signs List:

[0027] 100 - battery

[0028] 110 - cell

[0029] 120 - cell coating film; 121 - film body; 121a - film body

[0030] 122 - support assembly; 1221 - support; 1222a - central region; 1222b - edge region; 1222c - gap; 1223 - elastic expansion piece DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0032] The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In the embodiments of the present application, the words "exemplary" or "for example" are used to mean example, instance, or illustration. Any embodiment or design solution described herein as "exemplary" or "for example" should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present concepts in a concrete manner. The words "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In the embodiments of the present application, the words "exemplary" or "for example" are used to mean example, instance, or illustration. Any embodiment or design solution described herein as "exemplary" or "for example" should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present concepts in a concrete manner.

[0033] In the prior art, the battery charging and discharging process is accompanied by the expansion and contraction of the cell. During long-term cyclic use, the uneven thickness of the cell is unevenly stressed, and the adhesion between the positive plate and the negative plate at the corresponding position gradually weakens, the interface contact gradually deteriorates, leading to edge lithium precipitation on the four sides, affecting the cycle life and safety performance of the battery.

[0034] Therefore, the present application provides a battery, which applies a supporting force to both sides of the thickness of the cell to ensure the adhesion between the positive plate and the negative plate of the cell.

[0035] For ease of description and understanding, with reference to Figure 1 , the thickness direction of the cell can be Figure 1The width direction of the battery cell can be the Z direction in the battery cell Figure 1 The length direction of the battery cell can be the Y direction in the battery cell Figure 1 The X direction in the battery cell.

[0036] With reference to Figures 1 to 8 The battery 100 can include a battery cell 110 and a battery cell coating film 120.

[0037] The battery cell 110 is the core component of the battery 100, which is used to convert chemical energy into electrical energy to provide power for various electronic devices. The battery cell 110 of the present embodiment can be a wound battery cell or a laminated battery cell. Among them, the wound battery cell refers to a battery cell formed by winding the positive plate, the separator and the negative plate after layering, and the laminated battery cell refers to a battery cell formed by sequentially layering a plurality of positive plates, separators and negative plates.

[0038] In the battery 100 of the present embodiment, one or more battery cells 110 can be arranged in the thickness direction of the battery 100.

[0039] The battery cell coating film 120 generally has good electrical insulation performance, thermal stability and barrier performance, which improves the safety performance, reliability and extends the service life of the battery 100. The battery cell coating film 120 can include a film body 121 and a support assembly 122.

[0040] The film body 121 can be a Mylar film or other types of films. The film body 121 can be the part of the battery cell coating film 120 that coats the battery cell 110, and the film body 121 is provided with two film bodies 121a respectively opposite to the two side surfaces of the battery cell 110 in the thickness direction, and a connecting film corresponding to the other surface of the battery cell 110.

[0041] It can be understood that the two film bodies 121a and the connecting film can form a closed battery cell coating film 120 for coating the battery cell 110.

[0042] The support assembly 122 can be provided on one side surface of at least one of the two film bodies 121a facing the battery cell 110, and the support assembly 122 is supported on the surface of the battery cell 110 opposite to the support assembly 122. For example, the support assembly 122 can be provided only on one side surface of one film body 121a facing the battery cell 110 to exert a supporting action on the battery cell 110, and the side of the battery cell 110 in the thickness direction which is not provided with the support assembly 122 abuts against the film body 121a which is not provided with the support assembly 122. Alternatively, the support assembly 122 can be provided on the two film bodies 121a respectively, and the two side surfaces of the battery cell 110 in the thickness direction opposite to each other between the two film bodies 121a are supported, so that the battery cell 110 is more uniformly stressed.

[0043] It can be understood that when the support assembly 122 supports the surface of the battery cell 110 in the thickness direction, the support region of the support assembly 122 at least includes the uneven thickness region of the edge of the battery cell 110, and can also include more regions on the surface of the battery cell 110 in the thickness direction.

[0044] It should be noted that when the battery 100 has a plurality of battery cells 110, the battery cell covering film 120 covers all the battery cells 110, and at this time the support assembly 122 supports the end surface of the two battery cells 110 at both ends of the battery 100 in the thickness direction, and the battery cells 110 support each other.

[0045] Optionally, the battery cell 110 of the utility model can be a laminated battery cell, and of course, it can also be a wound battery cell. The wound battery cell is also subjected to the constraint force of winding. The support assembly 122 of the present embodiment is provided, and the structural stability of the wound battery cell is higher, thereby prolonging the service life of the wound battery cell.

[0046] Referring to Figure 2 , Figure 3 , Figure 4 and Figure 5 , the support assembly 122 can include a support piece 1221 and an elastic expansion piece 1223.

[0047] The support piece 1221 can include a central region 1222a and an edge region 1222b surrounding the central region 1222a, and the central region 1222a is connected with the film body 121, and a gap 1222c is formed between the edge region 1222b and the film body 121. Exemplarily, the edge region 1222b can be warped towards the battery cell 110 relative to the film body 121, and the gap 1222c is formed between the edge region 1222b and the film body 121, thereby providing a certain deformation space for the support piece 1221. In the process of expansion and contraction of the battery cell 110 during charging and discharging, the support piece 1221 deforms in the gap 1222c, and the support effect on the battery cell 110 is stable, and the support piece 1221 will not be disabled due to the expansion and contraction of the battery cell 110.

[0048] Optionally, the support piece 1221 can also be a shell structure, the central region 1222a is protruded away from the surface of the battery cell 110, the central region 1222a forms a connecting end surface opposite to one side surface of the battery cell 110 in the thickness direction, the connecting end surface is fixedly connected to the corresponding film body 121a, the support piece 1221 is supported at the edge of the battery cell 110, and the uneven thickness part of the battery cell 110 is basically located at the edge of the battery cell, the support piece 1221 supports in a targeted manner, the support effect is good, the positive plate and the negative plate of the battery cell 110 can be continuously maintained in a state of adhesion, the interface contact is avoided from being deteriorated to cause lithium precipitation, and the service life of the battery 100 is prolonged, thereby improving the satisfaction of the user.

[0049] Reference Figure 6 The elastic expansion piece 1223 is arranged in the gap 1222c between the edge area 1222b and the film body 121, and two ends of the elastic expansion piece 1223 are connected with the film body 121 and the supporting piece 1221 respectively. In this way, the elastic expansion piece 1223 can exert a reset force on the supporting piece 1221, so that the supporting piece 1221 deforms synchronously with the expansion and contraction of the battery cell 110, thereby improving the reliability of the supporting assembly 122 and prolonging the service life of the battery 100.

[0050] Optionally, the elastic expansion piece 1223 can include but is not limited to a spring, an elastic gasket or an elastic expansion rod, so as to facilitate reduction of the production cost of the battery 100.

[0051] Optionally, the connection between the supporting piece 1221 and the film body 121 can be that the supporting piece 1221 and the film body 121 are integrally formed, or that the supporting piece 1221 and the film body 121 are hot-melt compounded, or that the supporting piece 1221 and the film body 121 are extrusion compounded, or that the supporting piece 1221 and the film body 121 are bonded by an adhesive, so as to facilitate improvement of the production efficiency of the battery cell covering film 120.

[0052] The battery 100 of the utility model, the battery cell covering film 120 covers the battery cell 110, and the supporting assembly 122 supports both sides of the battery cell 110 in the thickness direction.

[0053] The elastic expansion piece 1223 arranged in the gap 1222c between the film body 121 and the edge area 1222b exerts a supporting force on the supporting piece 1221. In the process of charging expansion deformation of the battery cell 110, the uneven position of the thickness of the edge of the battery cell 110 abuts against the edge area 1222b, thereby supporting the edge area 1222b. The edge area 1222b deforms towards the film body 121 along with the expansion of the battery cell 110. In the process of discharging contraction of the battery cell 110, the edge area 1222b is reset by the elastic action of the elastic expansion piece 1223 and the elastic action of itself. In other words, in the process of expansion and contraction of the battery cell 110, the supporting piece 1221 deforms synchronously, and the adhesion between the supporting piece 1221 and the battery cell 110 is good, so that the supporting piece 1221 and the battery cell 110 do not come off contact due to the expansion and contraction of the battery cell 110. The positive plate and the negative plate of the battery cell 110 can be kept in the adhesion state continuously, so as to avoid deterioration of the interface contact and cause lithium precipitation, thereby prolonging the service life of the battery 100 and improving the satisfaction of users.

[0054] According to some embodiments of the present application, the thickness T of the support member 1221 is in the range of 0.1mm≤T≤3mm. For example, T can be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm or 3mm. Of course, the thickness T of the support member 1221 can also be other values, which can be selected according to the requirements of the designer, and the present embodiment does not limit this.

[0055] On the one hand, the thickness of the support member 1221 is not too thin (e.g. less than 0.1mm), which can cause the structural strength of the support member 1221 to be too low and easily broken, and cannot play a supporting effect on the battery cell 110. On the other hand, the thickness of the support member 1221 is not too large (e.g. more than 3mm), which can cause the support member 1221 to occupy too much internal space of the battery 100, resulting in a decrease in the energy density of the battery 100 and affecting the performance of the battery 100.

[0056] According to some embodiments of the present application, each battery cell 110 can include positive and negative electrode plates alternately arranged in the thickness direction of the battery cell 110, and the positive and negative electrode plates are separated by a separator. That is, the battery cell 110 of the present embodiment can be a stacked battery cell 110, and the stacked structure allows the use of active materials to be maximized in a limited space, thereby improving the energy density of the battery cell 110 and prolonging the use time of the battery 100.

[0057] Referring to Figure 1 According to some embodiments of the present application, the battery 100 further includes a housing, the housing is provided with a receiving cavity, the battery cell 110 and the battery cell coating film 120 are arranged in the receiving cavity, the number of battery cells is N, the size of the receiving cavity in the thickness direction of the battery cell 110 is D, the thickness of the battery cell 110 is t, and the thickness of the film body 121 is d, wherein D, t and d satisfy: 0.5≤T(D-2d) / Nt≤5, for example: the value of T(D-2d) / Nt can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5, of course, the present application does not limit this, and the value of T(D-2d) / Nt can be reasonably selected within the above range according to actual needs.

[0058] It can be understood that after the battery cell coating film 120 coats the battery cell 110, a certain space allowance is required to ensure that the battery cell 110 is smoothly packaged into the housing. Through experiments by the inventor, it is found that the battery cell 110 satisfying the above relationship has good space allowance during packaging, which can not only ensure that the battery cell 110 is packaged into the housing and reserve a certain space for the expansion of the battery 100, but also will not make the gap 1222c between the battery cell 110 in the housing and the housing too large, affecting the energy density of the battery 100.

[0059] According to some embodiments of the present application, the distance Lw between the opposite ends of the support 1221 along the width direction of the battery cell 110 satisfies Lw≤Wa, where Wa is the distance between the opposite ends of the negative plate along the width direction of the battery cell 110.

[0060] It can be understood that, for the stacked core battery, the distance between the opposite ends of the negative plate along the width direction of the battery cell 110 can be the width dimension of the negative plate, and the distance between the opposite ends of the negative plate along the length direction of the battery cell 110 can be the length dimension of the negative plate. For the wound core battery, the distance between the opposite ends of the wound outermost layer of the negative plate of the wound core in the width direction of the wound core is the distance between the opposite ends of the negative plate along the width direction of the battery cell 110. Similarly, the same applies to the opposite ends of the positive plate along the width direction of the battery cell 110 and the opposite ends along the length direction of the battery cell 110, which will not be described herein.

[0061] It can be understood that, for the performance of the battery 100, the geometric dimension of the negative plate of the battery cell 110 is generally larger than the geometric dimension of the positive plate of the battery cell 110. Lw≤Wa is satisfied to ensure that the support 1221 is supported in the side surface of the battery cell 110 along the thickness direction, thereby improving the reliability of the structure.

[0062] According to some embodiments of the present application, the distance Hh between the opposite ends of the support 1221 along the length direction of the battery cell 110 satisfies Hh≤Ha, where Ha is the distance between the opposite ends of the negative plate along the length direction of the battery cell 110. The support 1221 is supported in the side surface of the battery cell 110 along the thickness direction, thereby improving the reliability of the structure.

[0063] In this way, the dimensions of the support 1221 in the length direction and the width direction of the battery cell 110 do not exceed the dimensions of the circumferential edge of the battery cell 110, in other words, the edge region 1222b of the support 1221 does not exceed the edge of the surface of the battery cell 110 along the thickness direction, thereby ensuring the supporting effect of the support 1221 on the battery cell 110.

[0064] According to some embodiments of the present application, the support 1221 is at least one of PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), silica gel and foam. For example, the support 1221 can include one of PET, PP, PE, PVC, silica gel or foam, or the support 1221 can include a combination of the above materials, or the support 1221 can include all of the above materials.

[0065] In this way, the support 1221 can have sufficient mechanical strength and heat resistance, can provide stable support for the battery cell 110, and improve the structural strength of the battery 100. The support 1221 can also have good elasticity, which can deform synchronously with the expansion and contraction of the battery cell 110, ensure the support effect on the battery cell 110, and also provide a buffering effect for the battery cell 110, absorb vibration and impact, and protect the safety of the battery 100 during transportation and use.

[0066] Referring to Figure 3 According to some embodiments of the present application, the arc length L of the support 1221 along the width direction of the battery cell 110, the distance Wc between the opposite ends of the positive plate along the width direction of the battery cell 110, and the distance Wa between the opposite ends of the negative plate along the width direction of the battery cell 110 satisfy: Wc≤L≤Wa.

[0067] It can be understood that the periphery of the surface of the battery cell 110 formed by the lamination of the positive plate and the negative plate will form a thickness uneven area due to the negative plate exceeding the positive plate. Specifically, in the width direction of the battery cell, the thickness uneven area of the battery cell is located outside the edge of the positive plate and inside the edge of the negative plate, i.e., the Wa-Wc part. By making Wc≤L≤Wa, the support 1221 supports the thickness uneven area of the battery cell 110 without exceeding the edge of the battery cell 110, which improves the adhesion between the positive plate and the negative plate in the thickness uneven area of the battery cell 110, and is beneficial to prolong the service life of the battery cell 110.

[0068] It can be understood that the support 1221 of the present embodiment has a certain elasticity. When the battery 100 is fully charged, the battery cell 110 expands to the maximum thickness state, the pressure of the battery cell 110 on the support 1221 is the largest, and the support 1221 is compressed to an approximately flattened state. At this time, the arc length L of the support 1221 along the width direction of the battery cell 110 is approximately equal to the above-mentioned Lw, i.e., Lw≈L. Only when Wc≤Lw≈L≤Wa is satisfied at this time, the edge area of the support 1221 can still support the thickness uneven area of the battery cell 110 along the width direction, and provide support for the thickness uneven part of the battery cell 110, so that the adhesion between the positive plate and the negative plate is good.

[0069] The arc length H of the support 1221 along the length direction of the battery cell 110, the distance Hc of the positive electrode sheet along the length direction of the battery cell 110, and the distance Ha of the negative electrode sheet along the length direction of the battery cell 110 satisfy: Hc≤H≤Ha. In this way, in the length direction of the battery cell 110, the support 1221 supports the uneven thickness area of the battery cell 110 without exceeding the edge of the battery cell 110, improves the adhesion between the positive electrode sheet and the negative electrode sheet of the uneven thickness area of the battery cell 110, and is beneficial to prolong the service life of the battery cell 110.

[0070] Similarly, when the battery 100 is fully charged, the support 1221 is compressed to an approximately flattened state, and the arc length of the support 1221 along the length direction of the battery cell 110 is approximately equal to Hh, that is, Hh≈H. Only when Wc≤Lw≈L≤Wa at this time, the edge area of the support 1221 can still support the uneven thickness area of the battery cell 110 along the length direction, and provide support to the uneven thickness area of the battery cell 110 to improve the adhesion between the positive electrode sheet and the negative electrode sheet.

[0071] In summary, the support 1221 of the embodiment can support the circumferential edge of the area where the negative electrode sheet exceeds the positive electrode sheet, and the active material layer thinning area where the tabs are arranged on the negative electrode sheet and the positive electrode sheet. In this way, during the charging and discharging process of the battery, the support 1221 can continuously support the above-mentioned areas during the cycle expansion-shrinkage process of the battery cell 110, avoid interface contact deterioration in the above-mentioned areas, and cause the battery cell to appear lithium precipitation phenomenon.

[0072] Referring to Figure 3 According to some embodiments of the present application, the distance m1 between the center point of the support 1221 and the line connecting the opposite ends of the support 1221 along the width direction of the battery cell 110, the distance Lw of the support 1221 along the width direction of the battery cell 110, and the arc length L of the cross section of the support 1221 along the width direction of the battery cell 110 satisfy:

[0073] 0<2×m1×L / (m1^2+(0.5×Lw)^2)<3.14.

[0074] Referring to Figure 3In the first reference surface perpendicular to the width direction of the battery cell 110, the manufacturability of the support 1221 needs to be met, and the value of the central angle a in radian of the arc length L of the section of the support 1221 along the width direction of the battery cell 110 corresponds to a circle center 0, 0 < a < 3.14 (pi), assuming that the radius of the arc of the section of the support 1221 along the width direction of the battery cell 110 is R, L = R * a, and from the Pythagorean theorem, R^2 = (R-m1)^2 + (0.5*Lw)^2, and the above two formulas can be obtained a = 2*m1*L / (m1^2 + 0.5*Lw^2). In this way, the manufacturability of the support 1221 in the width direction can be ensured, and the production and manufacture of the support 1221 are facilitated.

[0075] Reference Figure 4 According to some embodiments of the present application, referring to the derivation process of the central angle corresponding to the arc length of the projection in the width direction, the distance m2 between the center point of the support 1221 and the line connecting the opposite ends of the support 1221 along the length direction of the battery cell 110, the distance Hh between the opposite ends of the support 1221 along the length direction of the battery cell 110, and the arc length H of the section of the support 1221 along the length direction of the battery cell 110 can satisfy:

[0076] 0 < 2*m2*H / (m2^2 + 0.5*Hh^2) < 3.14. In this way, the manufacturability of the support 1221 in the length direction of the battery cell 110 can be ensured, and the production and manufacture of the support 1221 are facilitated.

[0077] In some embodiments, in the direction from the center region 1222a to the edge region 1222b, the gap 1222c between the edge region 1222b and the film body 121 gradually increases. In this way, the transition from the center region 1222a to the edge region 1222b is a slanting gradual transition, which is beneficial to reduce stress concentration and avoid damage to the support 1221 during the deformation of the battery cell 110, thereby prolonging the service life of the support 1221.

[0078] Reference Figure 7 And Figure 8 According to some embodiments of the present application, the elastic expansion member 1223 is a plurality of elastic expansion members 1223, and the elastic expansion members 1223 are spaced apart. In this way, the spaced distribution of the plurality of elastic expansion members 1223 can effectively uniformly disperse external pressure and internal expansion stress to the support 1221, avoid stress concentration in a certain specific area, and improve the stability of the structure of the battery 100.

[0079] Reference Figure 7According to some embodiments of the present application, the periphery of the support member 1221 supports the uneven thickness area of the battery cell 110, and the plurality of elastic expansion members 1223 are evenly distributed along the periphery of the support member 1221. In this way, the support effect on the uneven thickness area of the battery cell 110 is enhanced, thereby ensuring the stable adhesion between the positive plate and the negative plate of the battery cell 110.

[0080] With reference to Figure 8 According to some embodiments of the present application, the projections of the plurality of elastic expansion members 1223 along the diagonal line of the reference surface of the support member 1221 are evenly distributed, wherein the length direction and the width direction of the battery cell 110 jointly define the reference surface, i.e., the reference surface can be a surface parallel to the X-Y plane. In this way, during the expansion and contraction of the battery cell 110, the support member 1221 is deformed under stress, and the elastic expansion members 1223 arranged in the diagonal line manner are beneficial to uniformly applying a reset force to the support member 1221, so that the support member 1221 and the battery cell 110 maintain good contact, thereby improving the reliability of the structure.

[0081] According to some embodiments of the present application, the edge region 1222b of the support member 1221 can have a first side and a second side, the edge region 1222b is connected to the center region 1222a through the first side, and the second side is away from the center region 1222a. The support member 1221 can be supported on the side wall of the battery cell 110 through the second side.

[0082] In the thickness direction of the battery cell 110, the distance between the second side and the film body 121a is h, the length of the elastic expansion member 1223 is L1, and L1 and h satisfy: 0.5h≤L1≤h. In this way, the elastic expansion member 1223 is arranged from the corner of the edge region 1222b of the support member 1221 to the center region 1222a along the diagonal line, 0.5h≤L1≤h, the length L1 of the elastic expansion member 1223 can gradually decrease, which is beneficial to uniformly distributing the stress on the support member 1221 and improving the reliability of the structure.

[0083] Optionally, the length L1 of the elastic expansion member 1223 can be 0.5mm-5mm. For example, L1 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm. L1 can also be other values, which can be selected by the designer according to the requirements, and the present embodiment does not limit this.

[0084] In this way, on the one hand, the length of the elastic telescopic member 1223 is prevented from being too short, so that the elastic telescopic member 1223 exerts an excessive pulling force on the support member 1221 away from the battery cell 110, affecting the supporting effect of the support member 1221 on the battery cell 110. On the other hand, the elastic telescopic member 1223 is prevented from being too long, so that the resetting force on the support member 1221 is reduced, so that the support member 1221 cannot adapt to the expansion and contraction process of the battery cell 110, affecting the performance of the battery 100.

[0085] According to some embodiments of the present application, the material of the elastic telescopic member 1223 is at least one of PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), TPE (thermoplastic elastomer) and TPR (thermoplastic rubber). For example, the elastic telescopic member 1223 can be one of the above materials, or the elastic telescopic member 1223 can be a combination of the above materials. In this way, the elastic telescopic member 1223 provides a certain mechanical support and resetting effect for the support member 1221, and provides a buffering effect for the battery cell 110, thereby improving the safety of the battery 100.

[0086] According to some embodiments of the present application, the support member 1221 is provided with a ventilation structure. The ventilation structure can be a groove extending to the edge region 1222b, or it can also be a ventilation hole penetrating through the support member 1221 in the thickness direction. When the battery cell 110 expands, the spacing between the side wall of the battery cell 110 and the support member 1221 is shortened. In order to avoid the formation of a vacuum cup effect between the side wall of the battery cell 110 and the central region 1222a of the support member 1221, which affects the contact between the pole pieces in the battery cell 110, the ventilation structure is provided to balance the pressure inside and outside the central region 1222a of the support member 1221, thereby improving the structural reliability of the battery 100.

[0087] The embodiments or implementations in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be mutually referred to.

[0088] It should be noted that the "one embodiment", "embodiment", "exemplary embodiment", "some embodiments" and the like mentioned in the specification can include specific features, structures or characteristics, but not necessarily every embodiment includes the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure or characteristic is described in combination with an embodiment, it is within the knowledge of those skilled in the art to realize such feature, structure or characteristic in combination with other embodiments that are explicitly or implicitly described.

[0089] In general, terminology can be understood at least in part from usage in context. For example, terms, such as "one or more" as used herein, can be taken to describe any feature, structure, or characteristic in the singular or can be taken to describe a combination of features, structures or characteristics in the plural sense. Similarly, terms, such as "a," "an," or "the," again, can be taken to convey a singular usage or a plural usage, depending at least in part on the context in which such terms are used.

[0090] It will be readily understood that the terms "on," "above," and "over," in the present disclosure, are to be interpreted in the broadest context possible so that "on" means not only "directly on" but also includes the meaning of "on with intervening features or layers therebetween," and "above" or "over" includes not only the meaning of "above" or "over" but also can include the meaning of "above" or "over" without intervening features or layers therebetween (i.e., directly on).

[0091] In addition, spatially relative terms, such as "beneath", "below", "lower", "above", "upper", and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0092] Finally, it should be noted that the above-described embodiments are merely intended to illustrate the technical solutions of the present application, but not to limit the same; even though the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that they can still make modifications to the technical solutions recorded in the above-described embodiments, or make equivalent replacements to some or all of the technical features thereof; and such modifications or replacements do not cause the essence of the corresponding technical solutions to depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery, characterized by, The battery comprises: an electric core; an electric core coating film, comprising: a film body provided with two film bodies respectively opposite to two side surfaces of the electric core in a thickness direction; a support assembly arranged on a surface of the film body facing the electric core, the support assembly comprises a support and an elastic expansion piece, the support comprises a central region and an edge region surrounding the central region, the central region is connected with the film body, and a gap is formed between the edge region and the film body; the elastic expansion piece is arranged in the gap between the edge region and the film body, and two ends of the elastic expansion piece are connected with the film body and the support respectively.

2. The battery of claim 1, wherein, The thickness T of the support ranges from 0.1 mm to 3 mm.

3. The battery of claim 2, wherein, The battery further comprises a shell provided with a receiving cavity, the electric core and the electric core coating film are arranged in the receiving cavity, the number of the electric cores is N, the size of the receiving cavity in the thickness direction of the electric core is D, the thickness of the electric core is t, and the thickness of the film body is d, wherein the D, the t and the d satisfy 0.5≤T(D-2d) / Nt≤5.

4. The battery of claim 3, wherein, The distance Lw between the opposite ends of the support in the width direction of the electric core and the distance Wa between the opposite ends of the negative plate of the electric core in the width direction of the electric core satisfy Lw≤Wa; and / or, the distance Hh between the opposite ends of the support in the length direction of the electric core and the distance Ha between the opposite ends of the negative plate of the electric core in the length direction of the electric core satisfy Hh≤Ha.

5. The battery of claim 3, wherein, The arc length L of the support in the width direction of the electric core, the distance Wc between the opposite ends of the positive plate of the electric core in the width direction of the electric core and the distance Wa between the opposite ends of the negative plate of the electric core in the width direction of the electric core satisfy Wc≤L≤Wa; and / or, The arc length H of the support in the length direction of the electric core, the distance Hc of the positive plate of the electric core in the length direction of the electric core and the distance Ha of the negative plate of the electric core in the length direction of the electric core satisfy Hc≤H≤Ha.

6. The battery of claim 1, wherein, In the direction from the central region to the edge region, the gap between the edge region and the film body gradually increases.

7. The battery of claim 6, wherein, The elastic expansion piece is multiple, and the elastic expansion pieces are distributed at intervals.

8. The battery of claim 7, wherein, The multiple elastic expansion pieces are uniformly distributed at intervals in the circumferential direction of the support.

9. The battery of claim 8, wherein, The edge region has a first side connected with the central region and a second side away from the central region, the distance between the second side and the film body is h, the length of the elastic expansion piece is L1, and the L1 and the h satisfy 0.5h≤L1≤h.

10. The battery of claim 2, wherein, The support is provided with a ventilation structure.

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