Protective film, naked battery cell and energy storage battery cell

Abstract

The utility model discloses a protective film, a bare cell and an energy storage cell, comprising: a diaphragm suitable for being bent to form a cladding body for cladding a cell package, the cladding body has an open liquid injection side, and electrolyte is suitable for being injected into the cell package through the liquid injection side; a plurality of circulation holes penetrating the inner and outer surfaces of the covering body; wherein the circulation holes are distributed in the surfaces of the two opposite sides, parallel to the liquid injection direction, of the wrapping body, and the circulation holes in the surface of each side are distributed at intervals from the edge close to the liquid injection side to the edge of the side opposite to the liquid injection side in the liquid injection direction. By adopting the structure, the infiltration effect of the core cladding can be improved, the core cladding is more uniformly infiltrated, and the infiltration efficiency is higher.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery manufacturing technical field, especially relate to a protective film, bare electric core and energy storage electric core. BACKGROUND

[0002] In the process of assembling the energy storage electric core, in order to avoid that the core shell causes friction damage to the core package, usually need to be covered with a layer of protective film outside the core package to form the bare electric core, then the bare electric core is placed into the core shell from the open side of the core shell, and the open side of the core shell is closed by the end cover and then welded to form the energy storage electric core.

[0003] After the assembly of the energy storage electric core is completed, the electrolyte is injected into the core shell from the injection hole on the end cover to soak the core package. Because the protective film is usually a Mylar film, affected by its characteristics, during the injection process, the electrolyte mainly flows into the core package from the end face of the core package facing the end cover, and a small part of the electrolyte flows into the core package from the gap between the protective film and the core package. The soaking channel is single, the core package is not soaked uniformly, the immersion efficiency is low, and the core package is hindered by the protective film. When the core package produces gas during use, the exhaust efficiency is low.

[0004] Therefore, it is necessary to improve the prior art to overcome the defects in the prior art. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a protective film, bare electric core and energy storage electric core to improve the soaking effect of the core package.

[0006] The utility model aims at providing a protective film, bare electric core and energy storage electric core to improve the soaking effect of the core package.

[0007] The diaphragm is suitable for being bent to form a cladding body cladding the core package, and the cladding body has an open injection side, and the electrolyte is suitable for being injected into the core package through the injection side.

[0008] A plurality of flow-through holes penetrate the inner and outer surfaces of the cladding body.

[0009] Among them, the flow-through holes are distributed on the surfaces of two opposite sides of the cladding body parallel to the injection direction, and the flow-through holes on each side of the surface are arranged from the edge close to the injection side to the edge opposite to the injection side along the injection direction.

[0010] Further, a plurality of bending lines are arranged on the diaphragm, the diaphragm is suitable for being bent into a square cladding body along the bending lines, the cladding body has two opposite cladding surfaces, and the flow-through holes are arranged on the two opposite cladding surfaces.

[0011] Further, the cladding body is a cuboid, and the flow-through holes are arranged in a rectangular array on the cladding surface with smaller area.

[0012] Further, the flow-through hole has a diameter of 2-4 mm, and the diaphragm has a length of 400-600 mm and a width of 400-600 mm.

[0013] Further, the diaphragm comprises:

[0014] The first edge is parallel to the liquid injection direction.

[0015] The second edge is connected between the two first edges and is arranged on both sides of the first edge.

[0016] The bending line is parallel to the first edge and is arranged along the second edge in four lines, and the adjacent two bending lines form a covering surface, and the first edge and the adjacent bending line form a fitting surface, and when the diaphragm is bent, the two fitting surfaces are at least partially stacked to form a covering surface.

[0017] Further, the flow-through hole is arranged on the fitting surface on both sides of the diaphragm and the covering surface in the middle, and the flow-through hole is arranged along the first edge in multiple groups to form a flow-through hole group, and the flow-through hole group is arranged along the second edge in multiple groups.

[0018] The two fitting surfaces for stacking are provided with at least one row of flow-through hole groups, and when the two fitting surfaces are stacked to a predetermined position, the flow-through hole groups of the two stacking areas are overlapped.

[0019] Further, the width of a single fitting surface is smaller than the width of the covering surface spaced therefrom, and the sum of the widths of the two fitting surfaces is greater than the width of the covering surface spaced therefrom.

[0020] The utility model provides a kind of bare electric core, comprising:

[0021] The core package comprises a core package main body, a positive electrode lug and a negative electrode lug,

[0022] The core package main body has a core package end face and a core package side face, and the positive electrode lug and the negative electrode lug are connected to the core package end face.

[0023] The aforementioned protective film is suitable for bending to form a covering body covering the core package side face.

[0024] The bracket is fixed to the core package end face, and the bracket comprises a retaining hole capable of retaining the position of the positive electrode lug and / or the negative electrode lug.

[0025] The positive pole lug and the negative pole lug each comprise a connecting end connected with the end face of the core pack and a mounting end opposite to the connecting end, the connecting end is accommodated in the retaining hole, and the mounting end extends out of the retaining hole to the outside of the support.

[0026] Further, the protective film is at least partially wrapped around the periphery of the support and is fixed to the support.

[0027] In addition, the utility model provides a kind of energy storage battery, comprising:

[0028] The aforementioned bare battery cell;

[0029] The core shell has at least one open side in the liquid injection direction, and the bare battery cell can be accommodated in the core shell from the open side of the core shell;

[0030] The cover plate comprises a cover plate body and a protruding portion arranged on the cover plate body, the cover plate body covers the open side of the core shell, and the protruding portion is accommodated in the core shell.

[0031] The protruding portion has a protruding portion side surface and a protruding portion end surface facing away from the cover plate body, the protruding portion side surface is in contact with the inner circumferential surface of the core shell, the protruding portion end surface is connected with the support, and is suitable for limiting the wrapping body in the opening direction of the core shell.

[0032] Compared with the prior art, the utility model has the following beneficial effects: the protective film can be bent to form a wrapping body for wrapping the core pack, so as to protect the core pack when the core pack is packed into the core shell; when electrolyte is injected into the core shell, the liquid injection side is usually arranged upward, part of the electrolyte flows from the top end surface corresponding to the liquid injection side to the bottom end surface to soak the core pack, and the other part of the electrolyte flows downward from the gap between the wrapping body and the core shell; since the flow-through holes are arranged on the wrapping body, the electrolyte can flow to the surface of the core pack through the flow-through holes in the process, the soaking effect of the core pack is improved, the exhaust efficiency is improved when the core pack produces gas, and the circulation performance is improved; in addition, the flow-through holes are distributed on the surfaces of two opposite sides of the wrapping body parallel to the liquid injection direction, the flow-through holes on the two sides cooperate with each other to shorten the soaking path of the electrolyte, so that the electrolyte can fully and quickly soak the core pack; since the flow-through holes on each side are arranged along the liquid injection direction from the edge close to the liquid injection side to the edge opposite to the liquid injection side, the electrolyte can uniformly flow to each position on the surface of the core pack, the core pack is more uniformly soaked, and the soaking efficiency is higher. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is the unfolded schematic view of the protective film of the utility model.

[0034] Figure 2 is the installation schematic view of the core pack and the support in the utility model.

[0035] Figure 3 is a structural schematic view of a bare battery cell of the utility model.

[0036] Figure 4 is Figure 3 is a structural schematic view in another direction.

[0037] Figure 5 is Figure 4 is a partial enlarged view at A.

[0038] Figure 6 is a schematic view of installation of the bracket and the cover plate in the utility model.

[0039] Figure 7 is Figure 6 partial schematic view.

[0040] Explanation of reference signs:

[0041] 1000, bare battery cell; 100, protective film; 110, diaphragm; 111, bending line; 112, first edge; 113, second edge; 120, cladding body; 121, cladding surface; 122, fitting surface; 1221, laminated area; 130, flow-through hole; 140, flow-through hole group; 200, core package; 210, core package main body; 211, core package end face; 212, core package side face; 220, positive electrode tab; 221, connecting end; 222, mounting end; 230, negative electrode tab; 300, bracket; 310, retaining hole; 320, first bracket part; 330, second bracket part; 400, cover plate; 410, cover plate main body; 411, cover surface; 420, convex part; 421, convex part side face; 422, convex part end face. DETAILED DESCRIPTION

[0042] In order to make the above objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, in order to facilitate the description, only the parts related to the present application are shown in the drawings, and not all the structures. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0043] The terms "comprising" and "having" and any variations thereof in the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally further comprises steps or units not listed, or optionally further comprises other steps or units inherent to the process, method, product or device.

[0044] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments.

[0045] Referring to Figures 1 to 3 As shown in the drawings, the protective film 100 corresponding to a preferred embodiment of the application comprises a film sheet 110, the film sheet 110 is suitable for being bent to form a cladding body 120 of a core package 200, the cladding body 120 has an open liquid injection side, electrolyte is suitable for being injected into the core package 200 through the liquid injection side. The protective film 100 further comprises a plurality of flow-through holes 130, the flow-through holes 130 penetrate the inner and outer surfaces of the cladding body 120, the flow-through holes 130 are distributed on the surfaces of two opposite sides of the cladding body 120 parallel to the liquid injection direction, and the flow-through holes 130 on each side of the surface are arranged in intervals along the liquid injection direction from the edge close to the liquid injection side to the edge opposite to the liquid injection side.

[0046] The protective film 100 can be bent to form the cladding body 120 of the core package 200, so as to protect the core package 200 when the core package 200 is loaded into the core shell; when electrolyte is injected into the core shell, the liquid injection side is usually arranged upward, part of the electrolyte flows from the top end surface corresponding to the liquid injection side of the core package 200 to the bottom end surface, so as to infiltrate the core package 200, and the other part of the electrolyte flows downward from the gap between the cladding body 120 and the core shell. Since the flow-through holes 130 are arranged on the cladding body 120, the electrolyte can flow to the surface of the core package 200 through the flow-through holes 130 in the process, which improves the infiltration effect of the core package 200, accelerates the exhaust efficiency when the core package 200 generates gas, and improves the circulation performance. In addition, the flow-through holes 130 are distributed on the surfaces of two opposite sides of the cladding body 120 parallel to the liquid injection direction, the flow-through holes 130 on the two sides cooperate with each other to shorten the infiltration path of the electrolyte, so that the electrolyte fully and quickly infiltrates the core package 200. Since the flow-through holes 130 on each side of the surface are arranged in intervals along the liquid injection direction from the edge close to the liquid injection side to the edge opposite to the liquid injection side, the electrolyte can uniformly flow to each position on the surface of the core package 200, the core package 200 is more uniformly infiltrated, and the infiltration efficiency is higher.

[0047] Further, the protective film 100 is generally a square sheet, specifically a Mylar film, which is made of frosted translucent PP material. The protective film 100 can be bent into a different shape of the covering body 120 according to the shape of the core package 200, and the covering body 120 can be cylindrical, square, etc., which is not limited in the utility model. Taking the square structure of the covering body 120 as an example, the film sheet 110 is provided with a plurality of bending lines 111, and the film sheet 110 is adapted to be bent along the bending lines 111 into the covering body 120, and the covering body 120 has two pairs of opposite covering surfaces 121, and the flow-through holes 130 are arranged on two opposite covering surfaces 121.

[0048] In the embodiment, the covering body 120 is preferably a cuboid, the flow-through holes 130 are arranged on the covering surfaces 121 with smaller areas, and are arranged in a rectangular array along the length direction and the width direction of the covering surfaces 121. Since the flow-through holes 130 are directly arranged on the protective film 100, the core package 200 has the risk of contacting the core shell, causing a safety hazard, and thus by arranging the flow-through holes 130 on two covering surfaces 121 with smaller areas, the risk of the core package 200 contacting the core shell can be effectively reduced.

[0049] Preferably, when the film sheet 110 is bent into the covering body 120, the projections of the flow-through holes 130 on the two covering surfaces 121 are completely overlapped in the direction perpendicular to the covering surfaces 121 provided with the flow-through holes 130, so that the flow-through holes 130 on both sides of the covering body 120 are symmetrically arranged, and the uniformity of the core package 200 is improved.

[0050] Further, the flow-through holes 130 can be circular holes, long holes, triangular holes or other arbitrary-shaped holes, and in the embodiment, the flow-through holes 130 are preferably circular holes, which are convenient to process and have good flow smoothness. The diameter of the flow-through holes 130 is 2-4 mm, the length of the film sheet 110 is 400-600 mm, and the width of the film sheet 110 is 400-600 mm. The width of the flow-through hole 130 array is about 21 mm, the length of the flow-through hole 130 array is about 543 mm, and is preferably equal to the width of the film sheet 110. By limiting the parameters of the protective film 100 to the above values, better electrolyte immersion effect can be achieved, and the safety of the core package 200 is good.

[0051] Further, the film sheet 110 includes a first edge 112 and a second edge 113, the number of the first edges 112 is two, and the first edges 112 are arranged in parallel, the first edges 112 are parallel to the liquid injection direction, and the second edges 113 are connected perpendicularly between the two first edges 112, the number of the second edges 113 is two, and the second edges 113 are arranged on both sides of the first edges 112.

[0052] Preferably, the number of bending lines 111 on the film sheet 110 is at least three, the bending lines 111 are parallel to the first edge 112 and are arranged at intervals along the second edge 113, and the covering surface 121 is formed between two adjacent bending lines 111, so as to simplify the bending step, facilitate the bending forming of the film sheet 110, and make the covering body 120 after bending have open sides on both sides in the liquid injection direction, so that the installation of the core package 200 is more convenient, and the two opposite end faces of the core package 200 are not blocked by the covering body 120, and the electrolyte flows more smoothly.

[0053] Further, in the embodiment, the number of bending lines 111 is preferably four, the first edge 112 and the bending line 111 adjacent thereto form a fitting surface 122, and after the film sheet 110 is bent, the two fitting surfaces 122 are at least partially laminated to cooperatively form a covering surface 121. By adopting the above structure, the bending step can be reduced, and after the film sheet 110 is bent, the two fitting surfaces 122 can be at least partially laminated, so as to be bonded by adhesive tape, glue or the like to fix the covering body 120.

[0054] The width direction of the fitting surface 122 and the covering surface 121 is parallel to the second edge 113, and preferably, the width dimension of a single fitting surface 122 is smaller than the width dimension of the covering surface 121 spaced therefrom, i.e., smaller than the width dimension of the covering surface 121 in the middle of the film sheet 110, and the sum of the width dimensions of the two fitting surfaces 122 is greater than the width dimension of the covering surface 121 in the middle. In this way, the covering body 120 can be formed while the size of the film sheet 110 is reduced and the material is saved.

[0055] When the number of bending lines 111 is four, the covering surface 121 includes a first covering surface in the middle of the film sheet 110 and two second covering surfaces respectively arranged on both sides of the first covering surface, and after the film sheet 110 is bent into the covering body 120, the two fitting surfaces 122 cooperatively form another first covering surface. The flow-through hole 130 can be arranged on the first covering surface or the second covering surface and arranged in a rectangular array along the first edge 112 and the second edge 113.

[0056] Preferably, the flow-through hole 130 is arranged on the first covering surface, i.e., the flow-through hole 130 is distributed on the fitting surfaces 122 on both sides of the film sheet 110 and the covering surface 121 in the middle, and the flow-through hole 130 is arranged at intervals along the first edge 112 to form a flow-through hole group 140, and the flow-through hole groups 140 are arranged at intervals along the second edge 113. For reference Figure 4 and Figure 5As shown, the laminated region 1221 of each of the two adhering surfaces 122 is provided with at least one row of flow-through hole groups 140, and when the two adhering surfaces 122 are laminated to the preset position, the flow-through hole groups 140 of the two laminated regions 1221 are overlapped. By using the above structure, the operator can take the flow-through hole groups 140 as a reference datum to adjust the relative position of the two adhering surfaces 122 along the second edge 113, that is, whether the two adhering surfaces 122 are laminated to the preset position is determined according to whether the flow-through hole groups 140 at the laminated region 1221 are overlapped or not, so as to ensure that the covering surface 121 formed by the cooperation of the adhering surfaces 122 is consistent with the covering surface 121 in the middle of the diaphragm 110.

[0057] In the embodiment, the covering surface 121 in the middle is provided with N rows of flow-through hole groups 140, and the two adhering surfaces 122 are of the same size and are each provided with N-1 rows of flow-through hole groups 140, N is an odd number, when the diaphragm 110 is bent into the covering body 120, only one row of flow-through hole groups 140 of the two adhering surfaces 122 near the first edge 112 is in the laminated region 1221 and corresponds to one row of flow-through hole groups 140 in the middle of the covering body 120, and the remaining flow-through hole groups 140 of the two adhering surfaces 122 correspond to different flow-through hole groups 140 of the covering body 120 in the middle one by one.

[0058] Further, referring to Figures 2 to 4 As shown, the utility model also provides a bare electric core 1000, including preceding protection film 100 and the core package 200 that the protection film 100 is covered. The core package 200 includes core package main body 210, positive pole lug 220 and negative pole lug 230, and the core package main body 210 has core package end surface 211 and core package side surface 212, and the core package end surface 211 is located in the direction of injection, and the positive pole lug 220 and the negative pole lug 230 are connected on the core package end surface 211, and the covering body 120 after the bending of protection film 100 is covered in the core package side surface 212, and is open structure in the direction perpendicular to the core package end surface 211.

[0059] The positive pole lug 220 and the negative pole lug 230 extend along the direction perpendicular to the core package end surface 211, and both include a connecting end 221 connected to the core package end surface 211 and a mounting end 222 opposite to the connecting end 221. Preferably, the bare electric core 1000 further includes a bracket 300 disposed on the core package end surface 211, the bracket 300 includes a retaining hole 310 for retaining the position of the positive pole lug 220 and / or the negative pole lug 230, the retaining hole 310 is a through structure in the direction perpendicular to the core package end surface 211, the connecting end 221 is accommodated in the retaining hole 310, and the mounting end 222 extends out of the bracket 300 from the retaining hole 310. The protection film 100 is at least partially covered outside the bracket 300 and fixed with the bracket 300. The protection film 100 can be bonded on the bracket 300 by hot melting, so as to be fixed.

[0060] Because the bare battery cell 1000 needs to be bent during installation into the shell, and the positive and negative tabs are made of multiple layers of aluminum foil, which is relatively soft, the utility model sets the bracket 300, which can protect the tab bending part from tearing and keep the position of the tab for subsequent assembly.

[0061] Specifically, the bracket 300 includes a first bracket portion 320 and a second bracket portion 330, which are arranged on both sides of the tab surface, and the first bracket portion 320 and the second bracket portion 330 are buckled with the cell pack end face 211, the retaining hole 310 is surrounded by the first bracket portion 320 and the second bracket portion 330, and when the first bracket portion 320 and the second bracket portion 330 are buckled to form the retaining hole 310, the first bracket portion 320 and the second bracket portion 330 can clamp the tab to keep the position of the tab.

[0062] The positive and negative tabs 220 and 230 can be arranged on two opposite cell pack end faces 211 of the cell pack body 210, in which case the brackets 300 on the two cell pack end faces 211 need to be provided with retaining holes 310; or the positive and negative tabs 220 and 230 can be arranged on the same cell pack end face 211, in which case the bracket 300 on the cell pack end face 211 without tabs does not need to be provided with a retaining hole 310. Preferably, the bracket 300 covers the entire cell pack end face 211 to avoid contact between the cell pack end face 211 and the inner wall of the shell, and the bracket 300 is a hollow structure to ensure smooth flow of electrolyte into the cell pack end face 211.

[0063] The installation process of the bare battery cell 1000 is as follows: first, install the bracket 300 on the cell pack end face 211 of the cell pack body 210; then fold the protective film 100 around the cell pack side surface 212 of the cell pack body 210 and fix the two laminated surfaces 122 with adhesive tape, glue, etc.; after the protective film 100 is wrapped, part of the protective film 100 is arranged around the outer periphery of the bracket 300, at which point the protective film 100 is hot-melted to the outer periphery of the bracket 300 to tightly connect the cell pack body 210, the protective film 100 and the bracket 300.

[0064] Further, the utility model also provides a kind of energy storage battery cell, including the bare battery cell 1000 of preceding description. Figure 6 And Figure 7As shown, the energy storage cell further comprises a core shell (not shown in the figure) and a cover plate 400. The core shell is open on at least one side in the liquid injection direction. When the positive tab 220 and the negative tab 230 are located on the same core package end face 211, the core shell can be provided with only one open side for the positive tab 220 and the negative tab 230 to extend out of the core shell. When the positive tab 220 and the negative tab 230 are arranged on two core package end faces 211 respectively, the core shell has two opposite open sides for the positive tab 220 and the negative tab 230 to extend out of the core shell respectively. The bare cell 1000 can be accommodated in the core shell from the open side of the core shell. The cover plate 400 corresponds to the open side of the core shell one by one, and is suitable for being fixed and sealed on the open side of the core shell, realizing the sealing of the core shell, and can be electrically connected with the mounting end 222 of the tab. The cover plate 400 and the core shell can be fastened by welding, threaded fasteners, etc. The open side of the cladding body 120 close to the positive tab 220 is the liquid injection side. The cover plate 400 adjacent to the positive tab 220 is provided with a liquid injection hole (not shown in the figure). The electrolyte can flow into the core package end face 211 and the gap between the core package side face 212 and the core shell through the liquid injection hole and the support 300.

[0065] Further, the cover plate 400 comprises a cover plate body 410 and a protruding portion 420 arranged on the cover plate body 410. The cover plate body 410 is sealed outside the open side of the core shell. The cover plate body 410 has a sealing surface 411 facing the open side of the core shell. The protruding portion 420 is arranged on the sealing surface 411. The protruding portion 420 is accommodated in the core shell. The protruding portion 420 has a protruding portion side surface 421 and a protruding portion end surface 422 facing away from the cover plate body 410. The protruding portion side surface 421 is in contact with the inner circumferential surface of the core shell to improve the positioning accuracy of the cover plate 400. The protruding portion end surface 422 can be connected with the support 300 through the open side of the cladding body 120 to improve the connection strength. In the opening direction of the core shell, the protruding portion end surface 422 can abut against the open side of the cladding body 120 to prevent the cladding body 120 from moving in the opening direction, thereby improving the reliability of the bare cell 1000 after being accommodated in the core shell.

[0066] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation based on the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A protective film (100) characterized by, The application relates to a membrane sheet (110) suitable for being bent to form a wrapping body (120) of a wrapping core package (200), the wrapping body (120) having an open liquid injection side, electrolyte being suitable for being injected into the core package (200) through the liquid injection side; a plurality of flow-through holes (130) penetrating the inner and outer surfaces of the wrapping body (120); wherein the flow-through holes (130) are distributed on the surfaces of the two opposite sides of the wrapping body (120) parallel to the liquid injection direction, and the flow-through holes (130) on each side are arranged in intervals along the liquid injection direction from the edge close to the liquid injection side to the edge opposite to the liquid injection side. The membrane sheet (110) is provided with a plurality of bending lines (111), and the membrane sheet (110) is suitable for being bent along the bending lines (111) to form the square wrapping body (120), the wrapping body (120) having two pairs of opposite wrapping surfaces (121), and the flow-through holes (130) are arranged on two opposite wrapping surfaces (121). The wrapping body (120) is a cuboid, and the flow-through holes (130) are arranged in a rectangular array on the wrapping surface (121) with a smaller area. The aperture of the flow-through hole (130) is 2-4 mm, the length of the membrane sheet (110) is 400-600 mm, and the width of the membrane sheet (110) is 400-600 mm.

2. The protective film (100) according to claim 1, characterized in that The membrane sheet (110) comprises:

3. The protective film (100) according to claim 2, characterized in that The first edge (112) is parallel to the liquid injection direction.

4. The protective film (100) according to claim 2, characterized in that The second edge (113) is vertically connected between the two first edges (112), and the second edge (113) is arranged on the two sides of the first edge (112).

5. The protective film (100) according to claim 2, characterized in that The bending line (111) is parallel to the first edge (112), and four bending lines (111) are arranged in intervals along the second edge (113), the two adjacent bending lines (111) forming a wrapping surface (121), and the first edge (112) and the adjacent bending line (111) forming a fitting surface (122), when the membrane sheet (110) is bent, the two fitting surfaces (122) are at least partially overlapped to form a wrapping surface (121). The flow-through holes (130) are arranged on the fitting surfaces (122) on the two sides of the membrane sheet (110) and the wrapping surface (121) in the middle, the flow-through holes (130) are arranged in intervals along the first edge (112) to form a flow-through hole group (140), and the flow-through hole groups (140) are arranged in intervals along the second edge (113). The overlapping area (1221) of the two fitting surfaces (122) for overlapping is provided with at least one row of flow-through hole groups (140), and the flow-through hole groups (140) of the two overlapping areas (1221) are overlapped when the two fitting surfaces (122) are overlapped to a preset position. ​ 6. The protective film (100) according to claim 5, characterized in that ​ ​ 7. The protective film (100) according to claim 5, characterized in that The width dimension of each of the two fitting surfaces (122) is smaller than the width dimension of the cladding surface (121) spaced apart from the fitting surface (122), and the sum of the width dimensions of the two fitting surfaces (122) is greater than the width dimension of the cladding surface (121) spaced apart from the fitting surfaces (122).

8. A bare cell (1000) characterized by, The application relates to a protection film (100) for a bare battery cell (1000), comprising: a core package (200) comprising a core package body (210), a positive electrode tab (220) and a negative electrode tab (230), the core package body (210) has a core package end surface (211) and a core package side surface (212), and the positive electrode tab (220) and the negative electrode tab (230) are connected to the core package end surface (211); the protection film (100) is adapted to be bent to form a cladding body (120) cladding the core package side surface (212); a support (300) is fixed to the core package end surface (211), and the support (300) comprises a retaining hole (310) capable of retaining the positive electrode tab (220) and / or the negative electrode tab (230) in position; the positive electrode tab (220) and the negative electrode tab (230) each comprise a connecting end (221) connected to the core package end surface (211) and a mounting end (222) opposite to the connecting end (221), the connecting end (221) is accommodated in the retaining hole (310), and the mounting end (222) extends out of the retaining hole (310) to the outside of the support (300).

9. The bare cell (1000) of claim 8, wherein, The protection film (100) is at least partially cladded on the outer periphery of the support (300) and is fixed to the support (300).

10. An energy storage cell, characterized by, The application relates to a bare battery cell (1000) comprising: the bare battery cell (1000) is accommodated in a core shell from an open side of the core shell in a liquid injection direction; a cover plate (400) comprising a cover plate body (410) and a protruding portion (420) arranged on the cover plate body (410), the cover plate body (410) is arranged on the outside of the open side of the core shell, and the protruding portion (420) is accommodated in the core shell; the protruding portion (420) has a protruding portion side surface (421) and a protruding portion end surface (422) facing away from the cover plate body (410), the protruding portion side surface (421) is in contact with the inner circumferential surface of the core shell, and the protruding portion end surface (422) is connected to the support (300) and is adapted to limit the cladding body (120) in the opening direction of the core shell. ​

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