Secondary battery and electric device

Abstract

The invention discloses a secondary battery and electric equipment. The secondary battery comprises a shell, an electrode assembly arranged in the shell and a pole electrically connected with the electrode assembly. The shell comprises a first wall and a third wall which are oppositely arranged in the first direction, and a second wall connected with the first wall and the third wall, and the second wall is inclined relative to the first wall. The pole comprises a first part arranged on the second wall and a second part connected with the first part, the projection of the first part is located in the projection of the second wall in the vertical direction of the second wall, and the second part protrudes out of the second wall in the direction away from the containing cavity. In the first direction, the distance between the third wall and the first wall is T, in the inclination direction of the second wall, the size of the second part is L, the included angle between the second wall and the first wall is alpha, T is smaller than or equal to 5 mm, L is larger than T, L is smaller than or equal to 3 mm, alpha is larger than or equal to 145 degrees and smaller than 180 degrees, or alpha is larger than 0 degree and smaller than or equal to 35 degrees. A pole of 3mm < = L can be conveniently arranged on the second wall, and the size additionally occupied by the secondary battery due to the arrangement of the pole is reduced.

Description

Technical Field

[0001] This application relates to the technical field of energy storage, and particularly to a secondary battery and an electrical device. Background Art

[0002] The secondary batteries in the prior art include hard-shell (such as steel shell, plastic shell) batteries and soft-pack batteries. Among them, the steel shell battery includes a housing and an electrode assembly. The housing is provided with a pole column, the electrode assembly is received in the housing, and at least one polarity of the electrode assembly can be led out through the pole column. Summary of the Invention

[0003] For the secondary batteries in the prior art, the inventor found that the pole column is generally arranged on the side wall of the housing. The conductive requirement of the pole column determines that the pole column itself has at least a certain volume. And when the number of tabs of the secondary battery is more and the discharge rate is larger, the requirement for the overcurrent capacity of the pole column is greater, that is, it is required that the pole column has a larger volume. However, when the size of the side wall in the thickness direction is small, the pole column will exceed the housing in the thickness direction, so that the secondary battery needs to additionally occupy the size in the thickness direction. Although the secondary batteries in the prior art can reduce the possibility of the pole column exceeding the housing in the thickness direction by reducing the radial size of the pole column, the pole column itself has certain requirements for the radial size, and the axial size of the pole column cannot be infinitely reduced, resulting in that the pole column is not convenient to be arranged on the side wall of the housing.

[0004] In view of the above situation, it is necessary to provide a secondary battery that can increase the settable space of the pole column and facilitate the arrangement of the pole column with a larger radial size on the side wall of the housing.

[0005] In the first aspect of this application, a secondary battery is provided, including a housing, an electrode assembly and a pole column. The housing includes a first wall, a second wall and a third wall. The first wall and the third wall are oppositely arranged in a first direction. The second wall connects the first wall and the third wall, and the second wall is inclined relative to the first wall. The housing is provided with a receiving cavity, and the electrode assembly is arranged in the receiving cavity. The pole column is arranged on the second wall and is electrically connected to the electrode assembly. The pole column includes a first part arranged on the second wall and a second part connected to the first part. Along the perpendicular direction of the second wall, the projection of the first part is located within the projection of the second wall, and the second part protrudes from the second wall in a direction away from the receiving cavity. Along the first direction, the distance between the third wall and the first wall is T, along the inclined direction of the second wall, the size of the second part is L, the included angle between the second wall and the first wall is α, T≤5mm, L>T, 3mm≤L, 145°≤α<180° or 0°<α≤35°.

[0006] Due to certain requirements for the overcurrent capacity of the terminal post, in a secondary battery with T ≤ 5 mm, where L > T, by arranging the first wall and the third wall opposite to each other, connecting the first wall and the third wall with the second wall, and disposing the terminal post on the second wall, with the second wall being inclined relative to the first wall, the available space for arranging the terminal post on the second wall can be increased, facilitating the arrangement of a terminal post with 3 mm ≤ L on the second wall, which is beneficial to increasing the electrical connection area between the terminal post and the tab of the electrode assembly. By setting 145° ≤ α < 180° or 0° < α ≤ 35°, the additional size required for the secondary battery in total due to the arrangement of the terminal post can be reduced. Moreover, as α increases from 145° to 180° or decreases from 35° to 0°, the additional size required for the secondary battery in total can be gradually reduced.

[0007] In one or more of the above embodiments, the first direction is the thickness direction of the outer casing. In this case, the possibility of the terminal post protruding from the outer casing in the width direction can be reduced. When multiple secondary batteries are arranged side by side in the width direction for power supply, it is beneficial to reduce the possibility of interference between multiple secondary batteries in the width direction.

[0008] In one or more of the above embodiments, 165° ≤ α < 180° or 0° < α ≤ 15°. By setting 165° ≤ α < 180° or 0° < α ≤ 15°, while reducing the additional size required for the secondary battery in total, the additional size required for the secondary battery in the length direction and the additional size required in the thickness direction can also be reduced respectively.

[0009] In one or more of the above embodiments, along the perpendicular direction of the second wall, the dimension of the second part is D, where 1.5 mm ≤ D ≤ 5 mm.

[0010] In one or more of the above embodiments, the second wall includes a first end connected to the first wall and a second end connected to the third wall, and the second wall extends from the first end to the second end along the inclined direction of the second wall. In this way, the contact area between the second end of the second wall and the third wall can be increased. When there are certain requirements for the contact area between the second end and the third wall, the second wall can be made thinner, which is beneficial to further reducing the loss of the energy density of the secondary battery.

[0011] In one or more of the above embodiments, the secondary battery further includes a plurality of first tabs connected to the electrode assembly, and the first tabs extend out of the electrode assembly. Each first tab is directly connected to the terminal post. In this case, the additional space required for gathering the plurality of first tabs in the receiving cavity can be reduced, which is beneficial to further reducing the loss of the energy density of the secondary battery.

[0012] In one or more of the above embodiments, the first tab is a positive tab, and the first tab is connected to the positive electrode of the electrode assembly. The secondary battery further includes a second tab connected to the negative electrode of the electrode assembly, and the second tab is electrically connected to the housing. The pole post is insulatively disposed on the second wall. In this case, the positive electrode of the electrode assembly can be electrically connected to the pole post. Compared with the negative electrode of the electrode assembly being electrically connected to the pole post, the positive electrode of the electrode assembly being electrically connected to the pole post can reduce the possibility of electrochemical corrosion or other adverse reactions occurring in the secondary battery due to the relatively high voltage of the positive electrode of the electrode assembly, thereby facilitating the improvement of the safety of the secondary battery.

[0013] In one or more of the above embodiments, the second tab is connected to the second wall. This is conducive to improving the convenience of electrically connecting the second tab to the housing.

[0014] In one or more of the above embodiments, the first tab extends out of the electrode assembly in the second direction, and the second direction is perpendicular to the first direction. The first tab closest to the first wall includes a connecting portion connected to the electrode assembly. The pole post includes a third portion connected to the first portion, and the third portion protrudes from the second wall toward the accommodating cavity. Along the second direction, the distance between the connecting portion and the third portion is d, and d ≤ 1 mm. In this case, on the premise that each first tab has sufficient space to be connected to the pole post, the distance between the electrode assembly and the pole post can be made as small as possible, thereby facilitating further reduction of the loss of the energy density of the secondary battery.

[0015] In one or more of the above embodiments, at least a part of the first tabs is bent toward the first wall, and at least a part of the first tabs is bent toward the third wall. In this case, since the second wall is inclined relative to the first wall, by bending some of the first tabs toward the first wall and some of the first tabs toward the third wall, it is conducive to reducing the interference between the first tabs when the first tabs are connected to the pole post, thereby facilitating the improvement of the convenience of connecting the first tabs to the pole post.

[0016] In one or more of the above embodiments, 2.5 mm ≤ T, L ≤ 8 mm.

[0017] In one or more of the above embodiments, the second wall is integrally provided with the first wall, and the second wall is welded or bonded to the third wall. By integrally providing the second wall with the first wall, the connection strength between the second wall and the first wall can be improved, thereby facilitating maintaining the inclination degree of the second wall relative to the first wall. By welding or bonding the second wall to the third wall, the connection stability between the second wall and the third wall can be improved.

[0018] In one or more of the above embodiments, the secondary battery further includes a plurality of first tabs connected to the electrode assembly, and the first tabs extend out of the electrode assembly. The first tabs are bent into a U shape toward the first wall and are electrically connected to the pole post.

[0019] In one or more of the above embodiments, the outer shell is a steel shell, which is conducive to improving the convenience of arranging the terminal post on the outer shell.

[0020] The second aspect of the present application provides an electrical device, including the secondary battery of the first aspect of the present application. The secondary battery has a relatively high energy density, which is conducive to improving the endurance of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view of the secondary battery provided by the first embodiment of the present application.

[0022] Figure 2 It is a perspective view of the secondary battery provided by the second embodiment of the present application.

[0023] Figure 3 It is a perspective view of the secondary battery provided by the third embodiment of the present application.

[0024] Figure 4 It is a sectional view of an embodiment of the present application along the Figure 2 mid-section line A-A.

[0025] Figure 5 It is a sectional view of an embodiment of the present application along the Figure 3 mid-section line B-B.

[0026] Figure 6 It is a sectional view of an embodiment of the present application along the Figure 3 mid-section line C-C.

[0027] Figure 7 It is a sectional view of another embodiment of the present application along the Figure 2 mid-section line A-A.

[0028] Figure 8 It is a sectional view of another embodiment of the present application along the Figure 3 mid-section line B-B.

[0029] Figure 9 It is a sectional view of yet another embodiment of the present application along the Figure 3 mid-section line B-B.

[0030] Figure 10 It is an overall schematic diagram of the electrical device provided by an embodiment of the present application.

[0031] DESCRIPTION OF MAIN ELEMENT SYMBOLS 1000, Electrical equipment; 100, Secondary battery; 10, Housing; 101, First housing; 102, Second housing; 103, Receiving cavity; 104, First straight line; 105, Second straight line; 11, First wall; 12, Second wall; 121, First end; 122, Second end; 13, Third wall; 14, Fourth wall; 141, Bending portion; 20, Electrode assembly; 21, Negative electrode tab; 22, Positive electrode tab; 23, Separator; 30, Terminal; 31, First part; 32, Second part; 33, Third part; 40, First tab; 41, Connecting portion; 50, Second tab; 60, Insulating member; X, First direction; Y, Second direction. Detailed implementation mode The following will describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0032] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present at the same time. When an element is considered to be "disposed on" another element, it can be directly disposed on the other element or there may be an intermediate element present at the same time.

[0033] Unless otherwise specified, the term "plurality" used herein refers to two or more.

[0034] The terms "first", "second", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] It should be understood that considering the factors of actual processing tolerances, in the technical solutions of this application, when two elements are arranged in parallel / perpendicular and in the same direction, there may be a certain included angle between the two elements, and a tolerance of 0 - ±10% is allowed between the two elements, and the two elements are greater than, equal to or less than the allowed tolerance of 0 - ±10%.

[0037] Embodiments of the present application provide a secondary battery, including a housing, an electrode assembly, and a pole column. The housing includes a first wall, a second wall, and a third wall. The first wall and the third wall are oppositely arranged along a first direction. The second wall connects the first wall and the third wall, and the second wall is inclined relative to the first wall. The housing is provided with a receiving cavity, and the electrode assembly is disposed in the receiving cavity. The pole column is disposed on the second wall and is electrically connected to the electrode assembly. The pole column includes a first portion disposed on the second wall and a second portion connecting the first portion. Along the perpendicular direction of the second wall, the projection of the first portion is located within the projection of the second wall, and the second portion protrudes from the second wall in a direction away from the receiving cavity. Along the first direction, the distance between the third wall and the first wall is T, along the inclined direction of the second wall, the dimension of the second portion is L, the included angle between the second wall and the first wall is α, T≤5mm, L>T, 3mm≤L, 145°≤α<180° or 0°<α≤35°.

[0038] In the secondary battery of the present application, since there are certain requirements for the overcurrent capacity of the pole column, in the secondary battery with T≤5mm, there is L>T. By arranging the first wall and the third wall oppositely, connecting the first wall and the third wall with the second wall, disposing the pole column on the second wall, and inclining the second wall relative to the first wall, the available space for the pole column on the second wall can be increased, facilitating the arrangement of the pole column with 3mm≤L on the second wall. By setting 145°≤α<180° or 0°<α≤35°, the additional size required for the secondary battery due to the arrangement of the pole column can be reduced. Moreover, as α increases from 145° to 180° or decreases from 35° to 0°, the additional size required for the secondary battery can be gradually reduced.

[0039] Hereinafter, some embodiments of the present application will be described in conjunction with the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0040] Please refer to Figures 1 to 9 , embodiments of the present application provide a secondary battery 100, including a housing 10, an electrode assembly 20, and a pole column 30. The housing 10 houses the electrode assembly 20, and the pole column 30 is disposed on the housing 10 and is electrically connected to the electrode assembly 20.

[0041] In some embodiments, the housing 10 is a steel shell. The pole column 30 can be disposed on the housing 10 by welding, which is beneficial to improving the convenience of disposing the pole column 30 on the housing 10. In some embodiments, the material of the housing 10 includes a steel alloy. In some embodiments, the material of the housing 10 further includes at least one of an aluminum alloy and a copper alloy.

[0042] In some embodiments, the housing 10 includes a first wall 11, a second wall 12, and a third wall 13. The first wall 11 and the third wall 13 are disposed opposite to each other along a first direction X. The second wall 12 connects the first wall 11 and the third wall 13, and the second wall 12 is inclined relative to the first wall 11. The so-called inclination means that the included angle between two walls is an acute angle or an obtuse angle. It should be understood that since the first wall 11 and the third wall 13 are disposed opposite to each other along the first direction X, the second wall 12 is also inclined relative to the third wall 13. The included angle between the second wall 12 and the first wall 11 and the included angle between the second wall 12 and the third wall 13 are complementary angles. When the included angle between the second wall 12 and the first wall 11 is an acute angle, the included angle between the second wall 12 and the third wall 13 is an obtuse angle; when the included angle between the second wall 12 and the first wall 11 is an obtuse angle, the included angle between the second wall 12 and the third wall 13 is an acute angle.

[0043] In some embodiments, the second wall 12 and the first wall 11 are integrally formed, which can improve the connection strength between the second wall 12 and the first wall 11, thereby facilitating maintaining the inclination degree of the second wall 12 relative to the first wall 11. The second wall 12 and the third wall 13 are welded or bonded, which is conducive to improving the connection stability between the second wall 12 and the third wall 13.

[0044] In some embodiments, please refer to Figure 4 or Figure 5 , the inclination direction of the second wall 12 is a straight line direction. The second wall 12 includes a first end 121 connected to the first wall 11 and a second end 122 connected to the third wall 13. The second wall 12 extends from the first end 121 along the inclination direction of the second wall 12 to the second end 122. Thus, the contact area between the second end 122 of the second wall 12 and the third wall 13 can be increased. When there are certain requirements for the contact area between the second end 122 and the third wall 13, the second wall 12 can be made thinner, which is conducive to further reducing the loss of the energy density of the secondary battery 100.

[0045] In some embodiments, please refer to Figure 1 and Figures 4 to 9 , the housing 10 includes a fourth wall 14. The fourth wall 14 is disposed opposite to the second wall 12 and connects the first wall 11 and the third wall 13. In some embodiments, the first wall 11, the second wall 12, and the fourth wall 14 are integrally formed, and the second wall 12 and the fourth wall 14 are welded to the third wall 13.

[0046] In some embodiments, please refer to Figures 4 to 9, the fourth wall 14 includes a bent portion 141 connected to the third wall 13, and the extending direction of the bent portion 141 is parallel to the third wall 13. When the wall thickness of the fourth wall 14 is small, the convenience of connection between the fourth wall 14 and the third wall 13 can be improved through the bent portion 141. The so-called small wall thickness of the fourth wall 14 means that the wall thickness of the fourth wall 14 is 75um to 200um. For example, the wall thickness of the fourth wall 14 is 75um, 100um, 150um or 200um.

[0047] In some embodiments, please refer to Figure 1 , the first direction X is the width direction of the housing 10. The housing 10 includes a first housing 101 and a second housing 102. The first wall 11, the second wall 12, the third wall 13 and the fourth wall 14 are all located in the first housing 101.

[0048] In some embodiments, please refer to Figure 2 or Figure 3 , the first direction X is the thickness direction of the housing 10. The housing 10 includes a first housing 101 and a second housing 102. The first wall 11 and the second wall 12 are both located in the first housing 101, and the third wall 13 is located in the second housing 102. Please refer to Figures 4 to 8 , the fourth wall 14 is also located in the first housing 101.

[0049] Please refer to Figures 4 to 9 , the housing 10 is provided with a receiving cavity 103, and the receiving cavity 103 is filled with an electrolyte. The electrolyte includes an electrolyte salt. In some embodiments, the electrolyte salt includes at least one of an organic lithium salt or an inorganic lithium salt. The electrolyte salt includes but is not limited to lithium hexafluorophosphate (LiPF 6 ), lithium bis(trifluoromethanesulfonyl)imide LiN(CF 3 SO 2 ) 2 (LiTFSI), lithium bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )(LiFSI), lithium hexafluorocesate (LiCsF 6 ), lithium perchlorate (LiClO 4 ), or lithium trifluoromethanesulfonate (LiCF 3 SO 3 ) and the like.

[0050] Please refer to Figures 4 to 9 , the electrode assembly 20 is disposed in the receiving cavity 103. The electrode assembly 20 includes a negative electrode tab 21, a positive electrode tab 22 and a separator 23, and the separator 23 separates the negative electrode tab 21 from the positive electrode tab 22.

[0051] In some embodiments, please refer to Figures 4 to 9, the electrode assembly 20 is a laminated structure, and a plurality of negative electrode plates 21 and a plurality of positive electrode plates 22 are alternately laminated, and the separator 23 is disposed between any adjacent negative electrode plate 21 and positive electrode plate 22. In some embodiments, the thickness direction of the electrode assembly 20 is parallel to the thickness direction of the housing 10.

[0052] In some embodiments, the electrode assembly 20 is a wound structure, and a single negative electrode plate 21 and a single positive electrode plate 22 are laminated and then wound, and the separator 23 is disposed between the negative electrode plate 21 and the positive electrode plate 22.

[0053] In some embodiments, the negative electrode plate 21 includes a negative current collector and a negative active material layer, and the negative active material layer is disposed on two opposite sides of the negative current collector in the thickness direction. The positive electrode plate 22 includes a positive current collector and a positive active material layer, and the positive active material layer is disposed on two opposite sides of the positive current collector in the thickness direction.

[0054] In some embodiments, when the electrode assembly 20 is a laminated structure, along the thickness direction of the electrode assembly 20, the active material layer of the outermost electrode plate is disposed on the side of the current collector facing away from the inside of the electrode assembly 20, which can reduce the space occupied by the redundant active material layer in the receiving cavity 103, and is beneficial to further reducing the loss of the energy density of the secondary battery 100.

[0055] In some embodiments, the material of the negative current collector includes at least one of copper, nickel, tantalum, and titanium, and the material of the positive current collector includes at least one of aluminum, nickel, tantalum, and titanium.

[0056] In some embodiments, the material of the negative active material layer includes at least one of graphite, hard carbon, soft carbon, silicon, silicon oxide material, and silicon carbon material. The material of the positive active material layer includes at least one of lithium cobaltate, lithium nickel cobalt manganate, lithium nickel cobalt aluminate, lithium iron phosphate, lithium manganese iron phosphate, and lithium manganate.

[0057] In some embodiments, the separator 23 is a film material such as a polyethylene film, a polypropylene film, a polyester film, or a polyimide film that can be insulated.

[0058] Please refer to Figure 4 , Figure 5 , Figures 7 to 9 , the pole column 30 is disposed on the second wall 12, and the pole column 30 is electrically connected to the electrode assembly 20, so as to lead out one polarity of the electrode assembly 20.

[0059] In some embodiments, the number of the pole columns 30 is two, and the two pole columns 30 are both arranged on the second wall 12. Among them, one pole column 30 is electrically connected to one polarity of the electrode assembly 20 and is conductively arranged on the second wall 12; the other pole column 30 is electrically connected to the other polarity of the electrode assembly 20 and is insulatedly arranged on the second wall 12. In some other embodiments, the two pole columns 30 are both insulatedly arranged on the second wall 12.

[0060] In some embodiments, the pole column 30 is insulatedly arranged on the second wall 12, the pole column 30 is electrically connected to one polarity of the electrode assembly 20, and the outer shell 10 is electrically connected to the other polarity of the electrode assembly 20.

[0061] In some embodiments, please refer to Figure 4 、 Figure 5 、 Figures 7 to 9 The secondary battery 100 includes a first tab 40. The first tab 40 is connected to one of the positive electrode or the negative electrode of the electrode assembly 20 and extends out of the electrode assembly 20 to be electrically connected to the pole column 30. The number of the first tabs 40 can be multiple.

[0062] In some embodiments, please refer to Figure 6 The secondary battery 100 includes a second tab 50. The second tab 50 is connected to the other of the positive electrode or the negative electrode of the electrode assembly 20. The number of the second tabs 50 can be multiple.

[0063] In some embodiments, the first tab 40 and the second tab 50 extend out of the electrode assembly 20 along the second direction Y towards the second wall 12. The second direction Y is perpendicular to the first direction X.

[0064] In some embodiments, the first tab 40 is welded and connected to one of the negative electrode plate 21 and the positive electrode plate 22, and the second tab 50 is welded and connected to the other of the negative electrode plate 21 and the positive electrode plate 22.

[0065] In some embodiments, the first tab 40 is integrally provided with one of the negative electrode plate 21 and the positive electrode plate 22, and the second tab 50 is integrally provided with the other of the negative electrode plate 21 and the positive electrode plate 22.

[0066] In some embodiments, the first tab 40 is welded and connected to the pole column 30, and the second tab 50 is welded and connected to the outer shell 10 or another pole column 30.

[0067] In some embodiments, please refer to Figure 6 The second tab 50 is connected to the second wall 12. This is beneficial to improving the convenience of the electrical connection between the second tab 50 and the outer shell 10.

[0068] In some embodiments, please refer to Figures 7 to 9, the secondary battery 100 includes an insulating member 60, and the pole column 30 is insulatingly disposed on the second wall 12 through the insulating member 60. In some embodiments, the insulating member 60 at least surrounds the outer periphery of the first portion 31 and is disposed between the second wall 12 and the first portion 31.

[0069] In some embodiments, the pole column 30 is cylindrical. In this case, the pole column 30 has a high degree of fit with the second wall 12, which can prevent the electrolyte from leaking easily from the second wall 12 and is beneficial to improving the sealing performance of the housing 10.

[0070] In some embodiments, the pole column 30 has a prismatic shape, a frustum shape, or other regular or irregular shapes.

[0071] In some embodiments, the pole column 30 penetrates through the second wall 12. Please refer to Figure 3 and Figure 4 , the pole column 30 includes a first portion 31 disposed on the second wall 12. Along the perpendicular direction of the second wall 12, the projection of the first portion 31 is located within the projection of the second wall 12. The axial direction of the pole column 30 may be parallel or non-parallel to the perpendicular direction of the second wall 12. The first portion 31 is the portion of the pole column 30 that coincides with the second wall 12 along the inclined direction of the second wall 12.

[0072] In some embodiments, please refer to Figure 4 、 Figure 5 、 Figures 7 to 9 , the pole column 30 includes a second portion 32 connected to the first portion 31, and the second portion 32 protrudes from the second wall 12 in a direction away from the receiving cavity 103. The second portion 32 can improve the convenience of the secondary battery 100 for outputting electrical energy outward.

[0073] In some embodiments, please refer to Figure 4 、 Figure 5 、 Figures 7 to 9 , the pole column 30 includes a third portion 33 connected to the first portion 31, and the third portion 33 protrudes from the second wall 12 in a direction close to the receiving cavity 103. The third portion 33 can improve the convenience of electrically connecting the pole column 30 to the electrode assembly 20.

[0074] In some embodiments, along the first direction X, the distance between the third wall 13 and the first wall 11 is T, and along the inclined direction of the second wall 12, the dimension of the second portion 32 is L, where T ≤ 5 mm, L > T, and 3 mm ≤ L. Along the inclined direction of the second wall 12, by measuring the radial dimensions at different positions of the second portion 32 and calculating the average value, the obtained average value can be regarded as the dimension L of the second portion 32.

[0075] In some embodiments, when the terminal post 30 is cylindrical and the axial direction of the terminal post 30 is parallel to the perpendicular direction of the second wall 12, the dimension L of the second portion 32 is the diameter of the second portion 32.

[0076] In some embodiments, 2.5 mm ≤ T, L ≤ 8 mm. For example, T is 2.5 mm, 3 mm, 4 mm or 5 mm, and L is 3 mm, 4 mm, 5 mm, 6 mm, 7 mm or 8 mm.

[0077] In some embodiments, along the perpendicular direction of the second wall 12, the dimension of the second portion 32 is D. 1.5 mm ≤ D ≤ 5 mm. For example, the value of D is 1.5 mm, 2 mm, 3 mm, 4 mm or 5 mm.

[0078] In some embodiments, 4.5 mm 2 ≤ L × D ≤ 9 mm 2 . For example, the value of L × D is 4.5 mm 2 、5 mm 2 、6 mm 2 、7.5 mm 2 or 9 mm 2 .

[0079] By arranging the first wall 11 opposite to the third wall 13, connecting the first wall 11 and the third wall 13 with the second wall 12, disposing the terminal post 30 on the second wall 12, and inclining the second wall 12 relative to the first wall 11, the available space for arranging the terminal post 30 on the second wall 12 can be increased, facilitating the arrangement of the terminal post 30 with L ≥ 3 mm on the second wall 12, and being beneficial to increasing the electrical connection area between the terminal post 30 and the tab of the electrode assembly 20.

[0080] The above-mentioned first direction X is the thickness direction of the housing 10, and the second wall 12 is inclined relative to the first wall 11. In this case, the possibility of the terminal post 30 protruding from the housing 10 in the width direction can be reduced. When multiple secondary batteries 100 are arranged side by side in the width direction for power supply, it is beneficial to reduce the possibility of interference between the multiple secondary batteries 100 in the width direction.

[0081] In some embodiments, referring to Figure 4 and Figure 7 , the included angle between the second wall 12 and the first wall 11 is α, 0° < α < 90°. For example, α is 5°, 15°, 25°, 35°, 45°, 60°, 75° or 85°. In some embodiments, 90° < α < 180°. For example, α is 95°, 105°, 120°, 135°, 145°, 155°, 165° or 175°. It should be understood that the available space for arranging the terminal post 30 on the second wall 12 is equivalent when α and (180° - α).

[0082] In some embodiments, 145° ≤ α < 180° or 0° < α ≤ 35°. By setting 145° ≤ α < 180° or 0° < α ≤ 35°, the total additional size required for the secondary battery 100 due to the provision of the terminal post 30 can be reduced. Moreover, as α increases from 145° to 180° or decreases from 35° to 0°, the total additional size required for the secondary battery 100 can be gradually reduced. The total additional size required for the secondary battery 100 refers to the sum of the additional size required for the secondary battery 100 in the length direction and the additional size required for the secondary battery 100 in the thickness direction after the terminal post 30 is provided, based on the length size and thickness size occupied by the outer case 10. In some embodiments, the additional size required for the secondary battery 100 in the length direction and the additional size required for the secondary battery 100 in the thickness direction can both be 0 mm, and the terminal post 30 can be completely disposed within Figure 5 the triangular region shown. The triangular region is determined as follows: Refer to Figure 5 , and in the perspective shown in Figure 5 , along the extension direction of the first wall 11, a first straight line 104 is made at one end of the first wall 11 close to the second wall 12, and along the perpendicular direction of the third wall 13, a second straight line 105 is made at one end of the third wall 13 close to the second wall 12, and the second straight line 105 is made to intersect the first straight line 104. At this time, the space enclosed by the first straight line 104, the second straight line 105, and the second wall 12 is the so-called triangular region.

[0083] In some embodiments, 165° ≤ α < 180° or 0° < α ≤ 15°. By setting 165° ≤ α < 180° or 0° < α ≤ 15°, while reducing the total additional size required for the secondary battery 100, the additional size required for the secondary battery 100 in the length direction and the additional size required for the secondary battery 100 in the thickness direction can also be respectively reduced.

[0084] In some embodiments, each first tab 40 is directly connected to the terminal post 30 respectively. In this case, the additional space required to gather multiple first tabs 40 in the receiving cavity 103 can be reduced, which is beneficial to further reducing the loss of the energy density of the secondary battery 100. In some embodiments, each second tab 50 is directly connected to the outer case 10 respectively.

[0085] In some embodiments, the first tab 40 is a positive tab, the second tab 50 is a negative tab, the first tab 40 is connected to the positive electrode of the electrode assembly 20, and the second tab 50 is connected to the negative electrode of the electrode assembly 20. The second tab 50 is electrically connected to the housing 10, and the terminal post 30 is insulatingly disposed on the second wall 12. In this case, the negative electrode of the electrode assembly 20 can be electrically connected to the terminal post 30. Compared with the positive electrode of the electrode assembly 20 being electrically connected to the terminal post 30, the negative electrode of the electrode assembly 20 being electrically connected to the terminal post 30 can reduce the possibility of electrochemical corrosion or other adverse reactions occurring in the secondary battery 100 due to the relatively high voltage of the positive electrode of the electrode assembly 20, thereby being beneficial to improving the safety of the secondary battery 100.

[0086] In some embodiments, referring to Figure 5 and Figure 8 , the first tab 40 closest to the first wall 11 includes a connecting portion 41 connected to the electrode assembly 20. Along the second direction Y, the distance between the connecting portion 41 and the third portion 33 is d, and d ≤ 1 mm. In this case, on the premise that each first tab 40 has sufficient space to be connected to the terminal post 30, the distance between the electrode assembly 20 and the terminal post 30 can be made as small as possible, thereby being beneficial to further reducing the loss of the energy density of the secondary battery 100.

[0087] In some embodiments, referring to Figure 4 , Figure 5 , Figure 7 or Figure 8 , at least a part of the first tabs 40 are bent toward the first wall 11, and at least a part of the first tabs 40 are bent toward the third wall 13. In this case, since the second wall 12 is inclined relative to the first wall 11, by bending some of the first tabs 40 toward the first wall 11 and some of the first tabs 40 toward the third wall 13, it is beneficial to reduce the interference between the first tabs 40 when the first tabs 40 are connected to the terminal post 30, thereby being beneficial to improving the convenience of connecting the first tabs 40 to the terminal post 30.

[0088] In some embodiments, referring to Figure 9 , the first tab 40 is bent into a U shape toward the first wall 11 and is electrically connected to the terminal post 30, which is beneficial to improving the stability of the electrical connection between the first tab 40 and the terminal post 30. A plurality of first tabs 40 are first gathered to form a tab bundle, and then the tab bundle is bent into a U shape and electrically connected to the terminal post 30. In some embodiments, the tab bundle is welded to the terminal post 30.

[0089] In some embodiments, the secondary battery 100 includes a fixing member (not shown in the figure), and the fixing member is disposed in the accommodating cavity 103. The electrode assembly 20 and the housing 10 are fixedly connected through the fixing member. In this case, the possibility of the electrode assembly 20 moving relative to the housing 10 can be reduced, thereby facilitating the reduction of the risk of the secondary battery 100 failing due to the separation of the first tab 40 from the terminal 30. The situations where the electrode assembly 20 moves relative to the housing 10 include the situations such as the secondary battery 100 dropping or vibrating.

[0090] In some embodiments, the fixing member has adhesiveness. One side of the fixing member is adhered to the housing 10, and the other side of the fixing member is adhered to the electrode assembly 20.

[0091] In some embodiments, the fixing member is hot melt adhesive.

[0092] Please refer to Figure 10 , an embodiment of the present application provides an electrical device 1000, including the secondary battery 100 as described above. The secondary battery 100 has a relatively high energy density, which is beneficial to improving the endurance of the electrical device 1000. The electrical device 1000 includes, but is not limited to, electronic devices such as mobile phones, tablet computers, and laptop computers.

[0093] To verify the influence of the solution provided by the present application on the secondary battery 100, the inventors of the present application conducted the following experimental analysis. The experiment included 54 groups of embodiments, and the experimental results were recorded in Table 1, Table 2, and Table 3. In each group of experiments, the first wall 11 and the third wall 13 of the secondary battery 100 were relatively arranged along the thickness direction, the terminal 30 was in a cylindrical shape, and the axial direction of the terminal 30 was parallel to the perpendicular direction of the second wall 12. It should be noted that although only the cases where α≥90° are listed in Table 1 to Table 3, according to the fact that the angle between the second wall 12 and the first wall 11 and the angle between the second wall 12 and the third wall 13 are complementary angles, it is easy to infer the cases where α≤90°, which will not be elaborated.

[0094] Table 1 Table 2 Table 3 In Table 1 to Table 3, in order to make the current-carrying capacity of the terminal 30 in each embodiment basically the same, the value of L×D was controlled to be 6 mm 2Among them, the projection of the terminal post 30 along the first direction X can be calculated by the formula Dsinα - Lcosα, the projection of the second wall 12 along the first direction X can be calculated by the formula T / (-tanα), and the projection of the terminal post 30 along the second direction Y can be calculated by the formula Lsinα - Dcosα. If the projection of the terminal post 30 along the first direction X is greater than the projection of the second wall 12 along the first direction X, the additional size required for the secondary battery 100 along the length direction is the projection of the terminal post 30 along the first direction X minus the projection of the terminal post 30 along the second direction Y; otherwise, the additional size required for the secondary battery 100 along the length direction is 0 mm. If the projection of the terminal post 30 along the second direction Y is greater than the value of T, the additional size required for the secondary battery 100 along the thickness direction is the projection of the terminal post 30 along the second direction Y minus the value of T; otherwise, the additional size required for the secondary battery 100 along the thickness direction is 0 mm. The total additional size required for the secondary battery 100 is the additional size required for the secondary battery 100 along the length direction plus the additional size required for the secondary battery 100 along the thickness direction.

[0095] In Tables 1 to 3, if the additional sizes required for the secondary battery 100 along the length direction and the thickness direction are both 0 mm, and the value of L×D is less than or equal to the maximum rectangular area that can be set in the triangular area, the terminal post 30 can be completely arranged in the triangular area. At this time, the arrangement of the terminal post 30 will not cause the secondary battery 100 to require additional sizes in the length direction and the thickness direction. Among them, the maximum rectangular area that can be set in the triangular area can be calculated by the formula T×T / (-tanα) / 4.

[0096] In Table 1, according to Embodiments 1 to 8, when α < 130°, the total additional size required for the secondary battery 100 in Embodiments 2 to 8 is greater than the total additional size required for the secondary battery 100 in Embodiment 1, and the secondary battery 100 needs to occupy additional sizes in the length direction and the thickness direction; according to Embodiments 1 and 9 to 18, when 130° ≤ α < 180°, the total additional size required for the secondary battery 100 in Embodiments 9 to 18 is less than the total additional size required for the secondary battery 100 in Embodiment 1, and, as α increases, the total additional size required for the secondary battery 100 in Embodiments 9 to 18 gradually decreases.

[0097] In Table 2, according to Embodiments 19 to 29, when α < 145°, the total additional size required for the secondary battery 100 in Embodiments 20 to 29 is larger than the total additional size required for the secondary battery 100 in Embodiment 19, and the secondary battery 100 needs to additionally occupy sizes in the length direction and the thickness direction; according to Embodiments 19 and 30 to 36, when 145° ≤ α < 180°, the total additional size required for the secondary battery 100 in Embodiments 30 to 36 is smaller than the total additional size required for the secondary battery 100 in Embodiment 19, and as α increases, the total additional size required for the secondary battery 100 in Embodiments 30 to 36 gradually decreases.

[0098] In Table 3, according to Embodiments 37 to 43, when α < 125°, the total additional size required for the secondary battery 100 in Embodiments 38 to 43 is larger than the total additional size required for the secondary battery 100 in Embodiment 37, and the secondary battery 100 needs to additionally occupy sizes in the length direction and the thickness direction; according to Embodiments 37 and 44 to 54, when 125° ≤ α < 180°, the total additional size required for the secondary battery 100 in Embodiments 44 to 54 is smaller than the total additional size required for the secondary battery 100 in Embodiment 37, and as α increases, the total additional size required for the secondary battery 100 in Embodiments 44 to 54 gradually decreases. That is to say, by setting 145° ≤ α < 180° in the present application, the total additional size required for the secondary battery 100 due to the arrangement of the pole 30 can be reduced. And as α increases, the total additional size required for the secondary battery 100 can be gradually reduced.

[0099] In Table 1, the additional sizes required for the secondary battery 100 in the length direction and the thickness direction in Embodiments 15 to 18 are both smaller than the additional sizes required for the secondary battery 100 in the length direction and the thickness direction in Embodiment 1.

[0100] In Table 2, the additional sizes required for the secondary battery 100 in the length direction and the thickness direction in Embodiments 34 to 36 are both smaller than the additional sizes required for the secondary battery 100 in the length direction and the thickness direction in Embodiment 19.

[0101] In Table 3, the additional dimensions required by the secondary battery 100 in the length direction and the thickness direction in Examples 47 to 54 are smaller than those required by the secondary battery 100 in the length direction and the thickness direction in Example 37. That is to say, by setting 165°≤α<180°, the present application can reduce the additional dimensions required by the secondary battery 100 in total, and can also reduce the additional dimensions required by the secondary battery 100 in the length direction and the thickness direction respectively.

[0102] In addition, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the present application, rather than to limit the present application. As long as it is within the substantial scope of the present application, appropriate changes and variations made to the above embodiments fall within the scope disclosed in the present application.

Claims

1. A secondary battery, characterized in that: include: The housing comprises a first wall, a second wall and a third wall, wherein the first wall and the third wall are arranged opposite to each other along a first direction, the second wall connects the first wall and the third wall, and the second wall is inclined relative to the first wall; the housing is provided with a receiving cavity; An electrode assembly, wherein the electrode assembly is disposed in the receiving cavity; as well as A pole, the pole is arranged on the second wall and is electrically connected to the electrode assembly; the pole comprises a first portion arranged on the second wall and a second portion connected to the first portion, along the perpendicular direction of the second wall, the projection of the first portion is located within the projection of the second wall, and the second portion protrudes from the second wall in a direction away from the receiving cavity; Along the first direction, the distance between the third wall and the first wall is T, along the inclination direction of the second wall, the size of the second part is L, and the angle between the second wall and the first wall is α, T≤5mm, L>T, 3mm≤L, 145°≤α<180° or 0°<α≤35°.

2. The secondary battery according to claim 1, characterized in that: The first direction is a thickness direction of the shell.

3. The secondary battery according to claim 1, characterized in that: 165°≤α<180° or 0°<α≤15°.

4. The secondary battery according to claim 1 or 3, characterized in that: Along the perpendicular direction of the second wall, the dimension of the second portion is D, 1.5 mm≤D≤5 mm.

5. The secondary battery according to claim 1, characterized in that: The second wall includes a first end connected to the first wall and a second end connected to the third wall, and the second wall extends from the first end to the second end along an inclined direction of the second wall.

6. The secondary battery according to claim 1, characterized in that: The secondary battery further includes a plurality of first pole tabs connected to the electrode assembly, wherein the first pole tabs extend out of the electrode assembly; each of the first pole tabs is directly connected to the pole column.

7. The secondary battery according to claim 6, characterized in that: The first pole tab is a positive pole tab, which is connected to the positive pole of the electrode assembly; the secondary battery also includes a second pole tab connected to the negative pole of the electrode assembly, which is electrically connected to the shell; the pole column is insulated and arranged on the second wall.

8. The secondary battery according to claim 7, characterized in that: The second electrode tab is connected to the second wall.

9. The secondary battery according to claim 6, characterized in that: The first pole ear extends out of the electrode assembly along a second direction, and the second direction is perpendicular to the first direction; the first pole ear closest to the first wall includes a connecting portion connected to the electrode assembly, and the pole includes a third portion connected to the first portion, and the third portion protrudes from the second wall in a direction close to the accommodating cavity, and along the second direction, the distance between the connecting portion and the third portion is d, d≤1mm.

10. The secondary battery according to claim 6, characterized in that: At least a portion of the first electrode tab is bent toward the first wall, and at least a portion of the first electrode tab is bent toward the third wall.

11. The secondary battery according to claim 1 or 3, characterized in that: 2.5mm≤T, L≤8mm.

12. The secondary battery according to claim 1 or 3, characterized in that: The second wall is integrally formed with the first wall, and the second wall is welded or bonded to the third wall.

13. The secondary battery according to claim 12, characterized in that: The secondary battery further includes a plurality of first pole tabs connected to the electrode assembly, wherein the first pole tabs extend out of the electrode assembly; the first pole tabs are bent into a U shape toward the first wall and are electrically connected to the poles.

14. The secondary battery according to claim 1, characterized in that: The shell is a steel shell.

15. An electrical equipment, characterized in that: The invention comprises the secondary battery according to any one of claims 1 to 14.

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