Adapter, secondary battery, and electronic device

Abstract

An object of the present invention is to provide an adapter, a secondary battery, and an electronic device that at least improve the utilization efficiency of the space occupied by the adapter.SOLUTION: An embodiment of the present invention provides an adapter used for electrically connecting an electrode assembly and a terminal. The adapter includes a terminal fixing portion, an electrode assembly connecting portion provided to surround the terminal fixing portion, and a first transition portion connecting the terminal fixing portion and the electrode assembly connecting portion. The adapter has an electrode assembly connection side and a terminal connection side that are reversely distributed. Each of the first transition portion and the terminal fixing portion has a first surface and a first end surface located on a terminal connection side, and a second surface and a second end surface located on an electrode assembly connection side. The second surface protrudes in a direction away from the terminal connection side than the second end surface.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an adapter, a secondary battery, and an electronic device. [Background technology]

[0002] In the field of new energy power batteries, secondary batteries generally include an electrode assembly, a casing, a cover plate, etc. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator between the positive electrode sheet and the negative electrode sheet, which are stacked together and then wound to form an electrode assembly, which is then inserted into a casing. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the problems in the related art, the present invention provides an adapter, a secondary battery, and an electronic device that can improve the utilization efficiency of at least the space occupied by the adapter. [Means for solving the problem]

[0004] To achieve the above-mentioned object, an embodiment of the present invention provides an adapter for electrically connecting an electrode assembly and a terminal. The adapter includes a terminal fixing portion, an electrode assembly connection portion surrounding the terminal fixing portion, and a first transition portion connecting the terminal fixing portion and the electrode assembly connection portion. The adapter has an electrode assembly connection side and a terminal connection side that are distributed in opposite directions ("distributed in opposite directions" means that one side of the adapter is the electrode assembly connection side and the opposite side in the thickness direction is the terminal connection side). The first transition portion includes a first surface located on the terminal connection side and a second surface located on the electrode assembly connection side. The terminal fixing portion includes a first end face located on the terminal connection side and a second end face located on the electrode assembly connection side. The second surface protrudes in a direction away from the terminal connection side beyond the second end face.

[0005] In some embodiments, the first surface of the first transition portion protrudes away from the terminal. The adapter is integrally molded.

[0006] In some embodiments, the electrode assembly connection portion includes a third end face located on the terminal connection side and a fourth end face located on the electrode assembly connection side, and the second end face protrudes further away from the terminal connection side than the fourth end face by a first depth, the first depth being in the range of 0.01 mm to 5 mm.

[0007] In some embodiments, the range of the second depth to which the second surface of the first transition portion protrudes in the direction away from the terminal connection side beyond the second end face is 0.01 mm to 5 mm.

[0008] In some embodiments, the adapter further includes a second transition portion connecting between the first transition portion and the electrode assembly connection portion. The second transition portion includes a third surface located on the terminal connection side and a fourth surface located on the electrode assembly connection side. The third surface protrudes in a direction away from the electrode assembly connection side and does not extend beyond the first end face.

[0009] In some embodiments, the terminal fixing portion has a truncated cone shape, and in an orthogonal projection along the direction from the first end face to the second end face, the terminal fixing portion is two concentric circles, and / or the first transition portion is provided surrounding the terminal fixing portion.

[0010] An embodiment of the present invention further provides a secondary battery. The secondary battery includes an electrode assembly formed by sequentially stacking a positive electrode sheet, a first separator, a negative electrode sheet, and a second separator and then rolling the stack, and the adapter according to any one of the above-described embodiments. The terminal fixing portion is electrically connected to a terminal of the secondary battery, and the electrode assembly connecting portion is electrically connected to a tab of the electrode assembly.

[0011] In some embodiments, the electrode assembly includes a central hole, and at least a portion of the terminal fixing portion and / or the first transition portion is located within the central hole, or at least a portion of an orthogonal projection of the first transition portion along a direction from the first end surface to the second end surface is located within the central hole.

[0012] In some embodiments, the secondary battery is a cylindrical battery, and the ratio of the height to the diameter of the cylindrical battery is in the range of 1.7 to 3.3.

[0013] An embodiment of the present invention further provides an electronic device, which includes at least one of the adapter according to any one of the above-mentioned embodiments and the secondary battery according to any one of the above-mentioned embodiments. [Effects of the Invention]

[0014] The beneficial technical effects of the present invention are as follows:

[0015] An embodiment of the present invention shortens the distance between the second end face of the adapter's terminal fixing portion and the electrode assembly connection portion by providing a first transition portion that protrudes away from the terminal connection side, thereby reducing the distance between the electrode assembly and the terminal, reducing the height space required to be occupied by the adapter, and improving the utilization efficiency of the space occupied by the adapter.

[0016] In some embodiments of the present invention, lithium-ion batteries generate gas during cycling and storage, causing the battery's volume to expand. After gas generation, internal pressure compresses the terminals. Furthermore, lithium-ion batteries are prone to stress concentrations above and below the terminals under vibration. The provision of a first transitional portion can alleviate stress at the terminal fixing portion and the electrode assembly connection portion, preventing poor welding between the tab and the adapter and affecting battery performance. The first transitional portion also alleviates stress from the terminals from being transmitted to the electrode assembly connection portion. [Brief explanation of the drawings]

[0017] In order to more clearly describe the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. The drawings described below are only some embodiments of the present invention, and it is obvious that those skilled in the art can obtain other embodiments based on these drawings without expending creative efforts.

[0018] [Figure 1] 1 is a schematic diagram illustrating an electronic device according to an embodiment of the present invention when the electronic device is a vehicle. [Figure 2] 1 shows a perspective view of an embodiment in which a secondary battery according to an embodiment of the present invention is a cylindrical battery. [Figure 3] 1 illustrates a cross-sectional view of an embodiment in which a secondary battery according to an embodiment of the present invention is a cylindrical battery. [Figure 4] 1 illustrates an electrode assembly in an embodiment in which the secondary battery according to the present invention is a cylindrical battery. [Figure 5] 4 shows an enlarged view of the area A in FIG. 3 where the adapter is located. DETAILED DESCRIPTION OF THE INVENTION

[0019] For a better understanding of the spirit of the embodiments of the present invention, the following will further describe them in combination with preferred embodiments of the present invention.

[0020] Hereinafter, embodiments of the present invention will be described in detail. Throughout this specification, identical or similar components and components having identical or similar functions are represented by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are of explanatory and illustrative nature and are used to provide a basic understanding of the present invention. The embodiments of the present invention should not be construed as limiting the present invention.

[0021] As used herein, the terms "generally," "approximately," "substantially," and "about" are used to describe and account for small variations. When used in conjunction with an event or circumstance, these terms can refer to an instance where the event or circumstance occurs exactly, as well as an instance where the event or circumstance closely occurs.

[0022] In this specification, unless otherwise specified or limited, relative terms such as, for example, "center," "longitudinal," "horizontal," "front," "rear," "right," "left," "inner," "outer," "low," "tall," "horizontal," "vertical," "high," "low," "upper," "lower," "top," "bottom," and terms derived therefrom (e.g., "downward," "upward," etc.) should be construed as referring to the orientations set forth in the description or illustrated in the accompanying drawings. These relative terms are used for convenience of description and do not require the invention to be constructed or operated in a particular orientation.

[0023] For convenience of description, terms such as "first," "second," "third," etc. may be used herein to distinguish between different elements in a figure or series of figures. "First," "second," "third," etc. do not necessarily describe corresponding elements.

[0024] The present invention provides an electronic device 1000. The electronic device 1000 includes a battery pack 1002. An operating unit of the electronic device 1000 is electrically connected to the battery pack 1002 to receive power support. As an example, the electronic device 1000 is a vehicle, which may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be, but is not limited to, a pure electric vehicle, a hybrid vehicle, or a range-extending vehicle. The operating unit is a vehicle body, and the battery pack 1002 is installed at the bottom of the vehicle body and provides power support for running the vehicle or operating electrical components inside the vehicle. However, in some other embodiments, the electronic device 1000 may be a mobile phone, a portable device, a notebook computer, a boat, an airplane, an electric toy, an electric tool, or the like. Aircraft include airplanes, rockets, space shuttles, spacecraft, and the like. The operating unit may be a unit that obtains electrical energy from the battery pack 1002 and performs a corresponding operation, such as a blade rotation unit of an electric fan or a dust collection unit of a vacuum cleaner. The electric toys include stationary or mobile electric toys, such as game consoles, electric toy cars, electric toy boats, electric toy airplanes, etc. The electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planes, etc. The embodiments of the present invention are not particularly limited to the electronic device 1000 described above.

[0025] For convenience of explanation, the following embodiments will be described using an example in which the electronic device 1000 is a vehicle. Referring to FIG. 1 , a battery pack 1002 is provided inside the vehicle. The battery pack 1002 may be provided at the bottom, head, or rear of a vehicle body 1001. The battery pack 1002 may be used to supply power to the vehicle, for example, the battery pack 1002 may be used as an operating power source for the vehicle.

[0026] FIG. 2 shows a perspective view of a cylindrical secondary battery 100 according to an embodiment of the present invention. FIG. 3 shows a cross-sectional view of a cylindrical secondary battery 100 according to an embodiment of the present invention, which merely illustrates the position of the adapter 150 and does not show its specific shape. FIG. 4 shows an electrode assembly 120 of the cylindrical secondary battery 100 according to an embodiment of the present invention. FIG. 5 shows an enlarged view of area A in FIG. 3 where the adapter 150 is located. The secondary battery 100 includes a housing 110, an electrode assembly 120, a terminal 140, a terminal seal nail 50, and a cover plate 130. The terminal 140 and the adapter 150 are joined by laser welding the outside of the terminal 140, and then the top surface of the terminal 140 is welded and sealed using the terminal seal nail 50. The housing 110 includes an end wall 111 and a side wall 112 surrounding the end wall 111. As long as a stable sealing and electrical connection can be formed, the connection between the end wall 111 and the side wall 112 may be realized by several methods, such as integral stamping, integral casting, or split welding. The enclosure by the side wall 112 is not limited and may be cylindrical or prismatic, or may have any other closed loop contour that matches the end wall 111. In this embodiment, the outer edge of the end wall 111 is circular, and the side wall 112 is cylindrical and surrounds the outer edge of the end wall 111. A circular opening 113 is formed at one end of the side wall 112 opposite the end wall 111. A housing 110 surrounded by the end wall 111 and the side wall 112 defines a housing cavity for housing the electrode assembly 120, electrolyte, and other components necessary for the battery. Specifically, the diameter size of the housing 110 may be determined depending on the specific size of the electrode assembly 120, and may be, for example, 18 mm, 21 mm, 46 mm, etc. The material of the housing 110 may be various types, such as copper, iron, aluminum, steel, aluminum alloy, etc. To prevent the housing 110 from rusting during long-term use, the surface of the housing 110 may be plated with a layer of anti-rust material, such as metallic nickel.

[0027] The electrode assembly 120 is housed in the casing 110. The electrode assembly 120 is a component where an electrochemical reaction occurs in the secondary battery 100. One or more electrode assemblies 120 may be included in the casing 110. The electrode assembly 120 includes a wound structure formed by winding a positive electrode sheet 121, a first separator 131, a negative electrode sheet 123, and a second separator 132. Specifically, the electrode assembly 120 includes the positive electrode sheet 121, the first separator 131, the negative electrode sheet 123, and the second separator 132, which are wound around the axial direction of the casing 110. The positive electrode sheet 121 includes a positive electrode current collector 1211 and a positive electrode active material layer coated on the positive electrode current collector 1211. A first coated region 1212 coated with a positive electrode active material layer and a first non-coated region 1213 not coated with a positive electrode active material layer are formed on the positive electrode current collector 1211, and the first coated region 1212 and the first non-coated region 1213 are arranged along the axial direction of the casing 110. One end of the first non-coated region 1213 facing the height direction h of the secondary battery extends outside the separator 122 and is bent toward the axis of the casing 110 to form a stacked positive electrode tab 125. The negative electrode sheet 123 includes a negative electrode current collector 1231 and a negative electrode active material layer coated on the negative electrode current collector 1231. A second coated region 1232 coated with the negative electrode active material layer and a second uncoated region 1233 not coated with the negative electrode active material layer are formed on the negative electrode current collector 1231, and the second coated region 1232 and the second uncoated region 1233 are arranged along the axial direction of the casing 110. One end of the second uncoated region 1233 facing the height direction h of the secondary battery extends outside the separator 122 and is bent toward the axis of the casing 110 to form a stacked negative electrode tab 124. The first separator 131 and the second separator 132 are provided between the positive electrode sheet 121 and the negative electrode sheet 123, thereby isolating the positive electrode active material layer and the negative electrode active material layer. Taking the lithium ion cylindrical battery 100 as an example, the material of the positive electrode current collector 1211 may be aluminum, the positive electrode active material layer includes a positive electrode active material, which may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc. The material of the negative electrode current collector 1231 may be copper, and the negative electrode active material layer includes a negative electrode active material, which may be carbon, silicon, etc.The base material of the first separator 131 and the second separator 132 may be PP (polypropylene), PE (polyethylene), etc. To provide the cell with a protective and insulating function, the outside of the cell may be further covered with an insulating film, which may be composed of PP, PE, PET, PVC, or other polymer materials.

[0028] Furthermore, in the present invention, the positive electrode tab 125 faces the end wall 111 or the opening 113, and the negative electrode tab 124 faces the other end of the housing 110. In this embodiment, the positive electrode tab 125 faces the end wall 111 and is electrically connected to the terminal 140, causing the terminal to be positively charged. The negative electrode tab 124 faces the opening 113, and the housing 110 is electrically connected to the negative electrode tab 124, causing it to be negatively charged. However, in other embodiments, the negative electrode tab 124 may be connected to the terminal 140, and the positive electrode tab 125 may be connected to the housing 110.

[0029] The cap plate 130 is disposed to seal the opening 113. The outer edge shape of the cap plate 130 corresponds to the shape of the opening 113 and connects with the sidewall 112 to seal the opening 113. The mounting method of the cap plate 130 may be, but is not limited to, mechanical sealing or welding sealing. In this embodiment, the cap plate 130 uses mechanical sealing to seal and close the opening 113.

[0030] In one example of the secondary battery 100 of the present invention, the electrode assembly 120 is provided and sealed within the housing 110. Along the height direction h of the cylindrical battery 100, the electrode assembly 120 is provided between the end wall 111 and the roll groove 114, and the roll groove 114 can limit the axial movement of the electrode assembly 120 between the end wall 111 and the roll groove 114.

[0031] The present invention improves upon the embodiment in which the terminal fixing portion of the adapter and the surface of the electrode assembly connecting portion facing the electrode assembly are substantially flush with each other. The terminal fixing portion must be formed in a truncated cone shape to be electrically connected to the terminal. Therefore, the adapter of the above-described embodiment in which the surfaces facing the electrode assembly of the terminal fixing portion and the surface of the electrode assembly connecting portion facing the electrode assembly are large in height, resulting in poor space utilization efficiency.

[0032] Referring to FIG. 5 , an embodiment of the present invention provides an adapter 150 for electrically connecting an electrode assembly 120 and a terminal 140. The adapter 150 includes a terminal fixing portion 10, an electrode assembly connection portion 20 surrounding the terminal fixing portion 10, and a first transition portion 22 connecting the terminal fixing portion 10 and the electrode assembly connection portion 20. The adapter 150 has an electrode assembly connection side and a terminal connection side that are distributed back to back. The first transition portion 22 includes a first surface 221 located on the terminal connection side and a second surface 222 located on the electrode assembly connection side. The terminal fixing portion 10 includes a first end face 101 located on the terminal connection side and a second end face 102 located on the electrode assembly connection side. The second surface 222 protrudes in a direction away from the terminal connection side relative to the second end face 102. The embodiment of the present invention provides a first transition portion 22 that protrudes in a direction away from the terminal connection side, thereby shortening the distance between the second end surface 102 of the terminal fixing portion 10 of the adapter 150 and the electrode assembly connection portion 20, thereby reducing the distance between the electrode assembly 120 and the terminal 140, reducing the height space that the adapter 150 needs to occupy, and improving the utilization efficiency of the space occupied by the adapter 150. In some embodiments, the above-described shape of the adapter 150 may be formed by stamping, or may be formed by abutting the adapter 150 onto the terminal 140 and welding it.

[0033] In some embodiments of the present invention, gas is generated during cycling and storage of the lithium-ion secondary battery 100, causing the battery volume to expand. After gas generation, internal pressure compresses the terminal 140. Furthermore, the lithium-ion cylindrical battery 100 is prone to stress concentration above and below the terminal 140 under vibration conditions. The provision of the first transition portion 22 can alleviate stress on the terminal fixing portion 10 and the electrode assembly connection portion 20, preventing poor welding between the tabs 124 / 125 and the adapter 150 and affecting battery performance. The first transition portion 22 also alleviates stress transmission from the terminal 140 to the electrode assembly connection portion 20.

[0034] In some embodiments, the first surface 221 of the first transition portion 22 protrudes away from the terminal 140. The adapter 150 is integrally molded, i.e., the first transition portion 22, with the protrusion and recess described above, is not a separately welded protrusion onto the adapter 150.

[0035] In some embodiments, the material of the adapter 150 is aluminum.

[0036] In some embodiments, the electrode assembly connection portion 20 includes a third end surface 203 located on the terminal connection side and a fourth end surface 204 located on the electrode assembly connection side. The second end surface 102 protrudes a first depth in a direction away from the terminal connection side beyond the fourth end surface 204, and the first depth ranges from 0.01 mm to 5 mm. That is, the reduced distance (thereby reducing the height clearance) between the first end surface 101 and the fourth end surface 204 ranges from 0.01 mm to 5 mm.

[0037] In some embodiments, the second depth, which is the extent to which the second surface 222 of the first transition portion 22 protrudes beyond the second end face 102 in the direction away from the terminal connection side, ranges from 0.01 mm to 5 mm. A depth value of 0.01 mm or more ensures that the first transition portion 22 protrudes beyond the electrode assembly connection portion 20. A depth value of 5 mm or less ensures that the protrusion depth is not so great that it prevents the terminal fixing portion 10 from being able to contact the terminal 140.

[0038] In some embodiments, the adapter 150 further includes a second transition portion 24 connecting the first transition portion 22 and the electrode assembly connection portion 20. The second transition portion 24 includes a third surface 243 located on the terminal connection side and a fourth surface 244 located on the electrode assembly connection side. The third surface 243 protrudes away from the electrode assembly connection side and does not extend beyond the first end face 101. The fourth surface 244 of the second transition portion 24 also protrudes away from the electrode assembly connection side. By providing the second transition portion 24 protruding away from the electrode assembly connection side, the flatness of the electrode assembly connection portion is ensured as much as possible and stress concentration is avoided. On the other hand, if the third surface 243 of the second transition portion 24 extends beyond the first end face 101, the first end face 101 of the terminal fastening portion 10 will not be able to contact the terminal 140, resulting in a gap between the two and reducing the weld strength.

[0039] In some embodiments, the terminal fixing portion 10 has a truncated cone shape, and in an orthogonal projection from the first end face 101 to the second end face 102, i.e., an orthogonal projection along the direction facing the electrode assembly 120, the terminal fixing portion 10 is two concentric circles, and / or the first transition portion 22 is provided surrounding the terminal fixing portion 10. That is, the lateral size of the terminal fixing portion 10 decreases in the direction away from the electrode assembly 120. The terminal fixing portion 10 having a truncated cone shape can more accurately electrically connect with the terminal 140. The first transition portion 22 is a perfect circle.

[0040] An embodiment of the present invention further provides a secondary battery 100. The secondary battery 100 includes an electrode assembly 120 formed by sequentially stacking a positive electrode sheet 121, a first separator 131, a negative electrode sheet 123, and a second separator 132 and then rolling the stack, and an adapter 150 according to any one of the above-described embodiments. The terminal fixing portion 10 is electrically connected to a terminal 140 of the secondary battery 100, and the electrode assembly connecting portion 20 is electrically connected to a tab of the electrode assembly 120. The secondary battery 100 according to the embodiment of the present invention uses an adapter 150 having a first transition portion 22, thereby improving the space utilization efficiency of the secondary battery 100.

[0041] In some embodiments, the electrode assembly 120 includes a central hole 160. The central hole 160 is located in the central region of the positive electrode sheet 121, the first separator 131, the negative electrode sheet 123, and the second separator 132. At least a portion of the terminal fixing portion 10 and / or the first transition portion 22 is located within the central hole 160. Alternatively, an orthogonal projection of the first transition portion 22 along the direction from the first end surface 101 to the second end surface 102 is at least partially located within the central hole 160. When the battery vibrates, the central hole 160 provides a space to accommodate the first transition portion 22 and provides a desirable stress relief effect. The depth of the terminal fixing portion 10 and / or the first transition portion 22 recessed into the central hole 160 is, for example, 0.01 mm to 5 mm. When the terminal fixing portion 10 is recessed into the central hole 160, the recessed depth is at its maximum, and is equal to the depth to which the second end surface 102 of the terminal fixing portion 100 protrudes into the electrode assembly 120 beyond the electrode assembly connection portion 20. The central portion of the electrode assembly 120 / bare cell is the central hole 160. That is, the central portion is empty. The innermost circle from the central hole 160 is a separator, and the number of layers of the electrode sheet (foil material) at the inner circle is fewer than that at the outer circle. Referring to FIG. 4 , the number of layers of the positive electrode tab 125 and the negative electrode tab 124 in the region close to the central hole 160 is fewer. As a result, at least a portion of the terminal fixing portion 10 and the first transition portion 22 are accommodated inside the electrode assembly 120. This reduces the height of the first end surface 101 of the terminal fixing portion 10 relative to the electrode assembly 120, and also reduces the space that the terminal fixing portion 10 needs to occupy in the secondary battery 100, thereby improving the space utilization efficiency of the secondary battery 100. It should be understood that the number of layers of the positive electrode sheet 121 and the negative electrode sheet 123 is not limited to the number taught in FIG. 4, and the number of layers in an actual product may be, for example, 14 or more layers.

[0042] In some embodiments, the adapter 150 is a positive adapter.

[0043] In some embodiments, the secondary battery 100 is a cylindrical battery. The ratio of the height (the distance from the end wall 111 to the cap plate 130 as shown in FIG. 3 ) to the diameter (outer diameter) of the cylindrical battery ranges from 1.7 to 3.3. For example, the height is 80 mm and the diameter is 46 mm. Another example is a height of 15 mm and a diameter of 46 mm. In some embodiments, the cylindrical battery is a 4680 cylindrical battery. When the height-to-diameter ratio is within the above-mentioned range, the secondary battery 100 has a certain height, so that vibrations of the secondary battery 100 are transmitted in the height direction of the cylindrical battery during some processes. The adapter 150 relieves the corresponding stress, thereby improving the safety of the battery and preventing poor welding between the positive electrode tab 125 and the adapter 150.

[0044] An embodiment of the present invention further provides a battery pack 1002 including at least one of the adapter 150 of any one of the above-described embodiments and the secondary battery 100 of any one of the above-described embodiments.

[0045] An embodiment of the present invention further provides an electronic device 1000 including at least one of the adapter 150 of any one of the above-described embodiments and the secondary battery 100 of any one of the above-described embodiments (and the battery pack 1002 described above).

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications and changes to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are equally included in the protection scope of the present invention. [Industrial Applicability]

[0047] The present invention provides a first transitional portion to relieve stress at the terminal fixing portion and the electrode assembly connection portion, thereby preventing poor welding between the tab and the adapter and affecting battery performance. The first transitional portion also reduces the transmission of stress from the terminal to the electrode assembly connection portion. [Explanation of symbols]

[0048] 10: Terminal fixing part 20: Electrode assembly connection part 22: First transition section 24: Second transition section 50: Terminal seal nail 100: Secondary battery 101: First end surface 102:Second end surface 110: Housing 111: End wall 112: Side wall 113:Aperture 114: Roll Groove 120: Electrode assembly 121: Positive electrode sheet 1211: Positive electrode current collector 1212: 1st application area 1213: 1st non-coating area 123: Negative electrode sheet 1231: Negative electrode current collector 1232:Second application area 1233: 2nd non-coating area 124: Tab 125: Tab 130: Cover plate 131: First separator 132: Second separator 140: Terminal 150: Adapter 160: Center hole 203: Third end surface 204: 4th end face 221: 1st surface 222: 2nd surface 243:Third surface 244: 4th surface 1000:Electronic equipment 1001: Body 1002: Battery pack h: Height direction

Claims

1. An adapter used to electrically connect an electrode assembly and a terminal, A terminal fixing portion; an electrode assembly connection portion provided to surround the terminal fixing portion; a first transition portion connecting the terminal fixing portion and the electrode assembly connecting portion; Including, having an electrode assembly connection side and a terminal connection side that are distributed in opposite directions; the first transition portion includes a first surface located on the terminal connection side and a second surface located on the electrode assembly connection side, The terminal fixing portion includes a first end surface located on the terminal connection side and a second end surface located on the electrode assembly connection side, The second surface protrudes in a direction away from the terminal connection side beyond the second end face. characterized in that adapter.

2. the first surface of the first transition portion projects in a direction away from the terminal; The adapter is integrally molded characterized in that The adapter of claim 1 .

3. the electrode assembly connection portion includes a third end surface located on the terminal connection side and a fourth end surface located on the electrode assembly connection side; The second end surface protrudes by a first depth in a direction away from the terminal connection side beyond the fourth end surface, and the first depth ranges from 0.01 mm to 5 mm. characterized in that The adapter of claim 1 .

4. The second surface of the first transition portion protrudes from the second end face in a direction away from the terminal connection side to a second depth ranging from 0.01 mm to 5 mm. characterized in that The adapter of claim 1 .

5. a second transition portion connecting the first transition portion and the electrode assembly connection portion; Further comprising: the second transition portion includes a third surface located on the terminal connection side and a fourth surface located on the electrode assembly connection side, The third surface protrudes in a direction away from the electrode assembly connection side and does not exceed the first end surface. characterized in that 3. The adapter of claim 2.

6. The terminal fixing portion has a truncated cone shape, and when orthogonally projected along a direction from the first end surface to the second end surface, the terminal fixing portion is formed as two concentric circles; and / or The first transition portion is provided surrounding the terminal fixing portion, and / or The adapter is made of aluminum. characterized in that The adapter of claim 1 .

7. an electrode assembly formed by sequentially stacking a positive electrode sheet, a first separator, a negative electrode sheet, and a second separator and then rolling the stack; The adapter according to any one of claims 1 to 6. A secondary battery comprising: The terminal fixing portion is electrically connected to a terminal of the secondary battery, and the electrode assembly connecting portion is electrically connected to a tab of the electrode assembly. characterized in that Secondary battery.

8. the electrode assembly includes a central hole; At least a portion of the terminal fixing portion and / or the first transition portion is located within the central hole, or At least a portion of an orthogonal projection of the first transition portion along a direction from the first end surface to the second end surface is located within the central hole. characterized in that The secondary battery according to claim 7 .

9. It is a cylindrical battery, The height to diameter ratio ranges from 1.7 to 3.3 characterized in that The secondary battery according to claim 7 .

10. The secondary battery according to claim 7 is included. characterized in that electronic equipment.

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