Battery

Abstract

Battery, characterized in that it comprises: a housing body (1) having an open end at at least one end, wherein a housing wall of the housing body (1) is tapered at the open end to form at least one step structure (11) within the housing body (1); a cover plate (2) blocking the open end and welded to the housing body (1), the cover plate (2) abutting the step structure; wherein the circumference of the housing body (1) at the open end is “a” and the total length of the step structure is “b”, wherein 0.02≤b / a≤0.98 is satisfied.

Description

TECHNICAL FIELD

[0001] The present utility model relates to the technical field of batteries or accumulators, in particular to a battery. BACKGROUND

[0002] A battery typically includes an inner battery structure and an outer battery structure. The outer battery structure includes a case enclosing a receiving space. The inner battery structure includes a cell provided in the receiving space. The case typically includes a case body and a cover plate. In order to facilitate the positioning and mounting of the cover plate on the case body, a step structure is typically formed at the case mouth portion of the case body, so that the cover plate abuts against the step structure to limit the position, and then the cover plate and the case body are welded. However, setting the step structure causes the thickness of the case body to be tapered at the case mouth portion, resulting in poor structural strength of the case body.This also results in poor weld strength between the cover plate and the housing body, which leads to weld wire breakage under fatigue loading conditions. SUMMARY OF THE UTILITY MODEL

[0003] In view of the above, the present utility model provides a battery to solve the problem of the prior art that the thickness of the case body is tapered at the case mouth portion, resulting in poor structural strength of the case body and poor welding strength of the cover plate and the case body.

[0004] The present utility model relates to a battery comprising: a case body, at least one end of which is an open end, wherein the case wall of the case body is tapered at the open end to form at least one step structure inside the case body; a cover plate blocking the open end and welded to the case body, the cover plate abutting against the step structure; wherein a circumference of the case body surrounding the open end is "a" and the total length of the step structure is "b", satisfying 0.02 ≤ b / a ≤ 0.98.

[0005] Advantages: By limiting the ratio of the circumference of the enclosure body to the total length of the step structure, while ensuring the positioning effect of the step structure on the cover plate, ensuring the assembly quality and welding quality of the cover plate and the enclosure, ensuring that the enclosure wall at the open end of the enclosure body has sufficient thickness, thereby ensuring the structural strength of the enclosure body and meeting the welding requirements of the cover plate and enclosure body, and avoiding the occurrence of problems such as welding wire breakage. Especially when b / a>0.98, the length of the step structure accounts for too large a proportion, resulting in an excessively long area where the enclosure wall of the enclosure body needs to be tapered, which in turn leads to poor structural strength of the enclosure body at the open end.In this case, the housing body is prone to deformation or even fracture at the open end. In addition, an excessive length of the tapered portion of the housing wall of the housing body will also result in poor weld strength between the cover plate and the housing body, resulting in poor welding quality, causing problems such as weld cracks, and leading to failure of the assembly of the housing body and the cover plate. When b / a<0.02, the length of the step structure accounts for too small a proportion, and the step structure has insufficient confinement effect on the cover plate, which affects the assembly efficiency of the cover plate and the housing body and easily leads to misalignment of the cover plate and the housing body. Therefore, a higher weld strength between the cover plate and the housing body is required to ensure the connection reliability of the cover plate and the housing body.However, if the welding strength between the cover plate and the housing body is insufficient, it can also easily lead to assembly errors of the housing body and the cover plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] To more clearly illustrate embodiments of the present utility model or the technical solution in the prior art, the following briefly presents the drawings required for embodiments of the present utility model or provides an introduction to the prior art. The drawings described below are obviously some embodiments of the present utility model. Those skilled in the art can identify other drawings based on these drawings without any creative effort. Fig. 1 is a schematic structural diagram of a case body according to an embodiment of the present utility model; Fig. Figure 2 is a partially enlarged schematic representation of “A” in Fig. 1; Fig. 3 is a plan view of the Fig. 1 shown housing body; Fig. Figure 4 is a partially enlarged schematic representation of “B” in Fig. 3; Fig. 5 is a schematic structural diagram of a battery (cell not shown) according to an embodiment of the present invention; Fig. 6 is a plan view of the Fig. 5 battery shown; Fig. 7 is a cross-sectional view in the direction “CC” in Fig. 6; Fig. Figure 8 is a partially enlarged schematic representation of “D” in Fig. 7; Fig. 9 is a schematic structural diagram according to another embodiment of the Fig. Cover plate shown in Figure 8.

[0007] In the figures: 1. Case body; 11. Step structure; 12. Corner; 13. Case mouth section; 131. Second fillet; 14. Main body section; 141. First fillet; 15. First plate body; 16. Second plate body; 2. Cover plate; 21. Embedded section; 22. Cover section; 3. Receiving space. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0008] In order to clarify the purpose, technical solution, and advantages of the embodiments of the present utility model, the technical solution in the embodiments of the present utility model is described clearly and completely in combination with the drawings in the embodiment of the present utility model. Obviously, the described embodiments are a part of the embodiment of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments determined by those skilled in the art without creative work are within the scope of the present utility model.

[0009] Embodiments of the present utility model are described below in connection with the Fig. 1 to 9 described.

[0010] According to the embodiment of the present utility model, there is provided a battery comprising: a case body 1, at least one end of which is an open end, wherein the case wall of the case body 1 is tapered at the open end to form at least one step structure 11 within the case body 1; a cover plate 2 blocking the open end and welded to the case body 1, the cover plate 2 abutting against the step structure 11; wherein a circumference of the case body 1 surrounding the open end is "a", and the total length of the step structure 11 is "b", satisfying 0.02≤b / a≤0.98.

[0011] In the battery of the present embodiment, by limiting the ratio of the circumference of the case body 1 to the total length of the step structure 11 while ensuring the positioning effect of the step structure 11 on the cover plate 2, the assembly quality and welding quality of the cover plate 2 and the case body 1 are ensured, the case wall at the open end of the case body 1 is ensured to have a sufficient thickness, thereby ensuring the structural strength of the case body 11 and meeting the welding requirements of the cover plate 2 and the case body 1, and avoiding the occurrence of problems such as breakage of the welding wire.

[0012] In particular, when b / a>0.98, the length of the step structure 11 accounts for an excessive proportion, resulting in an excessively long region where the housing wall of the housing body 1 needs to be tapered, which in turn leads to poor structural strength of the housing body 1 at the open end. In this case, the housing body 1 is prone to deformation or even fracture at the open end wall. In addition, an excessive length of the tapered region of the housing wall of the housing body 1 also leads to poor welding strength between the cover plate 2 and the housing body 1, resulting in poor welding quality, causing problems such as weld breakage, and leading to failure of the assembly of the housing body 1 and the cover plate 2.When b / a<0.02, the length of the step structure 11 accounts for too small a proportion, and the step structure 11 has insufficient restraining effect on the cover plate 2, which affects the assembly efficiency of the cover plate 2 and the housing body 1, and misalignment of the cover plate 2 and the housing body 1 is likely to occur. Therefore, a higher welding strength between the cover plate 2 and the housing body 1 is required to ensure the connection reliability of the cover plate 2 and the housing body 1. However, if the welding strength between the cover plate 2 and the housing body 1 is insufficient, assembly errors of the housing body 1 and the cover plate 2 are also likely to occur.

[0013] Optionally, the value of “b / a” can be any of the following values: 0.02, 0.04, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.94, 0.96, 0.98 or a value between any two of the above values.

[0014] It should be noted that in the prior art, by tapering the housing wall of the two short sides along the width direction and / or the two long sides along the length direction of the open end of the housing body 1, a step structure 11 is formed on the two short sides or on the two long sides or on the entire circumference, resulting in an excessive length of the tapered portion of the housing body 1, thereby causing problems of insufficient structural strength of the housing body 1 and poor welding quality of the cover plate 2 and the housing body 1. In the present embodiment, by limiting the ratio of the length of the step structure 11 (iethe length of the tapered portion) to the circumference of the housing body 1, the tapered portion has a suitable length on the housing body 1, whereby not only the cover plate 2 can be effectively positioned using the step structure 11, but also the structural strength of the housing body 1 and the welding quality of the cover plate 2 and the housing body 1 are ensured.

[0015] It should be noted that with reference to Fig. 3 in the circumference of the housing body 1 around the open end, the circumference “a” of the housing body 1 refers to the path along the inner wall of the housing body 1 and the total length “b” of the step structure 11 refers to the total length of the inner edge of the step structure 11.

[0016] It should be noted that a single step structure 11 may be provided continuously along the circumference of the open end, or a plurality of step structures 11 may be provided at intervals along the circumference of the housing body 1 around the open end. When a single step structure 11 is provided, the total length "b" of the step structure 11 is the length of one step structure 11; when a plurality of step structures 11 are provided, the total length "b" of the step structure 11 is the sum of the lengths of the plurality of step structures 11.

[0017] It should also be noted that when a plurality of step structures 11 are provided at intervals along the circumference of the case body 1 around the open end, the distance between two adjacent step structures 11 is 40 mm to 400 mm. In particular, when the distance between two adjacent step structures 11 is too small, the dispersion effect of the plurality of step structures 11 in the circumference of the surrounding opening is poor. That is, the positions of the plurality of step structures 11 are too concentrated, whereby the confining force exerted by the step structures 11 on the cover plate 2 is too concentrated, and the confining effect of the step structure 11 on the cover plate 2 is poor.If the distance between two adjacent step structures 11 is too large, the cover plate 2 cannot be confined within the larger distance between the two adjacent step structures 11, whereby the confining effect of the step structure 11 on the cover plate 2 is insufficient and the positional accuracy of the cover plate 2 mounted on the housing body 1 is low.

[0018] Optionally, the distance between two adjacent step structures 11 can be arbitrarily selected from the following values: 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, 300 mm, 310 mm, 320 mm, 330 mm, 340 mm, 350 mm, 360 mm, 370 mm, 380 mm, 390 mm, 400 mm or a value between any two of the above values.

[0019] In one embodiment, the total length "b" of the step structure 11 satisfies 20 mm ≤ b ≤ 240 mm. In this arrangement, while ensuring the positioning effect of the step structure 11 on the cover plate 2 to ensure the assembly quality and welding quality of the cover plate 2 and the housing body 1, it is ensured that the housing wall at the open end of the housing body 1 has a sufficient thickness to ensure the structural strength of the housing body 1 and meet the welding requirements of the cover plate 2 and the housing body 1, thereby avoiding the occurrence of problems such as breakage of the welding wire.

[0020] It should be noted that when b>240 mm, the length of the step structure 11 is too long, resulting in the area where the housing wall of the housing body 1 needs to be tapered is too large, resulting in poor structural strength of the housing body 1 at the open end, and the housing body 1 is prone to deformation or even fracture at the open end. In addition, the excessive length of the tapered area of ​​the housing wall of the housing body 1 also results in poor welding strength between the cover plate 2 and the housing body 1, resulting in poor welding quality, causing problems such as weld breakage, and resulting in failure of the assembly of the housing body 1 and the cover plate 2.When b < 20 mm, the length of the step structure 11 is too short and the limiting effect of the step structure 11 on the cover plate 2 is insufficient, which affects the assembly efficiency of the cover plate 2 and the housing body 1, and misalignment of the cover plate 2 and the housing body 1 is easy to occur, so a higher welding strength between the cover plate 2 and the housing body 1 is required to ensure the connection reliability of the cover plate 2 and the housing body 1. However, when the welding strength between the cover plate 2 and the housing body 1 is insufficient, assembly failure of the housing body 1 and the cover plate 2 is also easy to occur. Therefore, by further limiting the value “b”, the assembly quality and welding quality of the cover plate 2 and the housing body 1 are further improved.

[0021] Optionally, the value of “b” can be any one of the following values: 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, 220 mm, 230 mm, 240 mm or a value between any two of the above values.

[0022] In one embodiment, the circumference "a" of the housing body 1 satisfies the condition of 200 mm ≤ a < 1000 mm. This arrangement facilitates the adjustment of the step structure 11 while ensuring the structural strength of the housing body 1 to meet the welding requirements of the cover plate 2 and the housing body 1 and prevent problems such as welding wire breakage.

[0023] It should be noted that when a > 1000 mm, the circumference of the enclosure body 1 is too large, which makes the volume of the cover plate 2 too large for the enclosure body 1. In order to ensure the confinement effect of the cover plate 2, a step structure 11 with a longer length is required to confine and support the cover plate 2, which results in the area where the enclosure wall of the enclosure body 1 needs to be tapered being too long, resulting in poor structural strength of the enclosure body 1 at the open end, and the enclosure body 1 at the open end being prone to deformation or even fracture.In addition, the excessive length of the tapered portion of the housing wall of the housing body 1 also leads to poor welding strength between the cover plate 2 and the housing body 1, resulting in poor welding quality, causing problems such as weld breakage, and resulting in failure of the assembly of the housing body 1 and the cover plate 2. When a<200mm, the circumference of the housing body 1 is too small, and the volume of the cover plate 2 that fits the housing body 1 is small. In order to ensure the welding quality of the cover plate 2 and the housing body 1, a tapered portion with a shorter length, that is, the step structure 11, is set to match the restricting effect of the cover plate 2. However, machining a step structure 11 with a shorter length on a housing body 1 with a smaller circumference is not convenient for machining and forming the step structure 11.

[0024] Optionally, the value of "a" can be any of the following values: 200 mm, 240 mm, 280 mm, 300 mm, 340 mm, 380 mm, 400 mm, 440 mm, 480 mm, 500 mm, 540 mm, 580 mm, 600 mm, 640 mm, 680 mm, 700 mm, 740 mm, 780 mm, 800 mm, 840 mm, 880 mm, 900 mm, 940 mm, 980 mm, 1000 mm or a value between any two of the above values.

[0025] In one embodiment, as in the Fig. 1 and Fig. As shown in Figure 3, the case body 1 has a quadrilateral prismatic structure. A battery with a quadrilateral prismatic structure is a commonly used battery structure currently, such as a prismatic battery and a blade battery. When the battery is integrated with a quadrilateral prismatic structure, the batteries can be arranged more closely together, thereby achieving a higher space utilization rate and thus improving the energy density of the battery module.

[0026] In particular, the housing body 1 comprises, as shown in the Fig. 1 and Fig. 3, a first plate body 15 and a second plate body 16. Two first plate bodies 15 that are opposite to each other are provided at intervals from each other, and two second plate bodies 16 that are opposite to each other are provided at intervals from each other, and the first plate bodies 15 and the second plate bodies 16 are provided one after the other. When only one end of the case body 1 is an open end, the first end of the two first plate bodies 15 and the two second plate bodies 16 that are on the same side encloses the open end; when both ends of the case body 1 have open ends, the first end of the two first plate bodies 15 and the two second plate bodies 16 that are arranged on the same side encloses one open end, and the second end of the two first plate bodies 15 and the two second plate bodies 16 that are arranged on the same side encloses the other open end.The connection between the adjacent first plate bodies 15 and the second plate bodies 16 forms a corner 12. Furthermore, a rounded structure can be formed at the corner 12, i.e., the first plate body 15 and the second plate body 16 are transitionally connected via the rounded structure. Of course, the corner 12 can also have a rectangular structure, i.e., the first plate body 15 and the second plate body 16 are vertically connected. Therefore, at least one of the first plate body 15, the second plate body 16, and the corner 12 is provided with a step structure 11. That is, the open end of the housing body 1 has four sides and four corners 12, and the step structure 11 is provided corresponding to at least one side, or the step structure 11 is provided corresponding to at least one corner 12.

[0027] It should be noted that in the present embodiment, for the case body 1 of the quadrangular prism structure in which the four corners 12 are all rounded structures, the circumference “a” of the case body 1 at the open end is the sum of the length of the two first plate bodies 15 along the inner wall, the length of the two second plate bodies 16 along the inner wall, and the arc length of the four rounded structures along the inner wall.

[0028] Specifically, in one embodiment, the open end of the housing body 1 has four corners 12, and the step structure 11 is provided correspondingly to at least two corners 12, satisfying 0.04≤b / a≤0.98. In this arrangement, while ensuring the structural strength of the housing body 1, the positioning effect of the step structure 11 on the cover plate 2 is enhanced, thereby improving assembly efficiency and quality.

[0029] It should be noted that the corners 12 of the housing body 1 of the quadrangular prism structure have relatively high structural strength. Therefore, the stepped structure 11 is provided at the corners 12 of the housing body 1, which has a relatively small impact on the overall structural strength of the housing body 1. In addition, the length of the stepped structure 11 is set relatively long, which also ensures the structural strength of the housing body 1.Therefore, the step structure 11 is provided at least two corners 12 of the housing body 1, and the value range of “b / a” is further limited, which not only ensures the structural strength of the housing body 1, prevents deformation and breakage of the housing body 1 at the open end and weld breakage due to poor welding quality of the cover plate 2 and the housing body 1, but also improves the restraining effect of the step structure 11 on the cover plate 2, thereby improving the assembly efficiency of the cover plate 2 and the housing body 1, and improves the positional accuracy of the cover plate 2 mounted on the housing body 1, ensures the welding reliability of the cover plate 2 and the housing body 1, thereby improving the assembly quality of the cover plate 2 and the housing body 1.

[0030] Furthermore, in one embodiment, the step structure 11 is provided at two diagonally arranged corners 12, satisfying 0.04 ≤ b / a ≤ 0.96. The cover plate 2 is confined by the diagonally arranged step structure 11, so that the confining force exerted on the step structure 11 is more evenly distributed, thereby better confining the cover plate 2. In this arrangement, while simultaneously improving assembly efficiency and quality, the positioning effect of the step structure 11 on the cover plate 2 is further improved, and the structural strength and welding quality of the housing body 1 are further ensured.

[0031] It should be noted that the cover plate 2 is limited by the diagonally arranged step structure 11, which can better limit the cover plate 2. Therefore, even if the length of the step structure 11 is set relatively short, the limiting effect on the cover plate 2 can be ensured.Therefore, the stepped structure 11 is set according to the two diagonally arranged corners 12 of the housing body 1, and the value range of "b / a" is further limited. This not only ensures the limiting effect of the stepped structure 11 on the cover plate 2, thus ensuring the assembly efficiency of the cover plate 2 and the housing body 1, but also ensures the positional accuracy of the cover plate 2 mounted on the housing body 1, ensures the welding reliability of the cover plate 2 and the housing body 1, thereby improving the assembly quality of the cover plate 2 and the housing body 1, and further improves the structural strength of the housing body 1. With this arrangement, problems such as deformation and breakage of the housing body 1 at the open end, as well as problems such as weld breakage due to poor welding quality of the cover plate 2 and the housing body 1, can be avoided.

[0032] As an alternative embodiment, the step structure 11 is arranged corresponding to the four corners 12, satisfying 0.04 ≤ b / a ≤ 0.94. In this arrangement, the restraining force exerted by the step structure 11 at the four corners 12 on the cover plate 2 is more uniform, so that the restraining effect on the cover plate 2 is improved. Therefore, the length of the step structure 11 can be further shortened.That is, when the step structure 11 is provided at each of the four corners 12 of the step structure 11, the value range of "b / a" is further limited and the limiting effect of the step structure 11 on the cover plate 2 is ensured, thereby ensuring the assembly efficiency of the cover plate 2 and the housing body 1 and ensuring the positional accuracy of the cover plate 2 mounted on the housing body 1, thereby ensuring the welding reliability of the cover plate 2 and the housing body 1, thereby improving the assembly quality of the cover plate 2 and the housing body 1, and further improving the structural strength of the housing body 1. In this arrangement, problems such as deformation and breakage of the housing body 1 at the open end and problems such as weld breakage due to poor welding quality of the cover plate 2 and the housing body 1 can be avoided.

[0033] In one embodiment, as in the Fig. 2, Fig. 8 and Fig. As shown in Figure 9, the housing wall of the housing body 1 forms a housing mouth portion 13 at the open end. The housing body 1 further includes a main body portion 14 connected to the side of the housing mouth portion 13 facing away from the open end, and the step structure 11 is formed on the side of the main body portion 14 facing the housing mouth portion. That is, the housing wall of the housing mouth portion 13 has a tapered portion relative to the housing wall of the main body portion 14, and the part of the housing wall of the main body portion 14 that exceeds the tapered portion of the housing wall of the housing mouth portion 13 forms a step structure 11.

[0034] It should be noted that the housing mouth portion 13 is configured to receive the cover plate 2, and the main body portion 14 is configured to receive the cell.

[0035] In particular, in the present embodiment, as shown in the Fig. 2 and Fig. 4, the main body portion 14 forms a first fillet 141 at the corner 12, and the housing mouth portion 13 forms a second fillet 131 at the corner 12. The first fillet 141 and the second fillet 131 enclose the step structure 11, wherein the radius of the first fillet 141 is "r1" and the radius of the second fillet 131 is "r2", so that r1>r2 is satisfied. In this arrangement, the step structure 11 formed by the first fillet 141 and the second fillet 131 is crescent-shaped. That is, the step structure 11 has a larger width in the middle position of the circumference of the housing body 1 around the open end, so that it can exert a larger restricting force on the cover plate 2 and can perform a better restricting function on the cover plate 2, thereby ensuring the positioning effect of the step structure 11 on the cover plate 2.In addition, since the corner 12 of the housing body 1 has higher structural strength than the plate body (first plate body 15 and second plate body 16) of the housing body 1, and the width of the step structure 11 gradually decreases near the two ends of the circumference of the housing body 1 around the open end, it can reduce the influence of the step structure 11 on the structural strength of the housing body 1 and then ensure the structural strength of the housing body 1, avoid deformation and breakage of the housing body 1 at the open end, and avoid breakage of the welding wire due to poor welding quality between the cover plate 2 and the housing body 1.

[0036] Furthermore, the radius "r1" of the first fillet 141 satisfies the condition of 0.5 mm ≤ r1 ≤ 5 mm, and the radius "r2" of the second fillet 131 satisfies the condition of 0.4 mm ≤ r2 ≤ 4.8 mm. In this arrangement, while ensuring the positioning effect of the cover plate 2, the structural strength of the housing body 1 is ensured and the welding requirements of the cover plate 2 and the housing body 1 are met, thus avoiding the occurrence of problems such as weld breakage.

[0037] It should be noted that if the values ​​of "r1" and "r2" are too large, the width of the step structure 11 becomes too small, and the confining force exerted by the step structure 11 on the cover plate 2 is weak, which affects the positioning effect of the step structure 11 on the cover plate 2. If the values ​​of "r1" and "r2" are too small, the thickness of the housing body 1 is reduced too much, which affects the structural strength of the housing body 1, and then easily causes the housing body 1 to deform and break at the open end, and the weld seam to break due to the poor welding quality of the cover plate 2 and the housing body 1.

[0038] Optionally, the value of “r1” can be any one of the following values: 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm, 5 mm or a value between any two of the above values.

[0039] Optionally, the value of “r2” can be any of the following values: 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm, 4.2 mm, 4.5 mm, 4.8 mm or a value between any two of the aforementioned values.

[0040] It should be noted that the housing (including the housing body 1 and the cover plate 2) is configured to enclose components such as the cell and the electrolyte. The housing body 1 can have various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. The shape of the housing body 1 can be determined according to the specific shape and size of the cell. The housing body 1 can be made of various materials, including, but not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0041] It should be further explained that the cover plate 2 refers to a component that covers the open end of the housing body 1 to isolate the housing space of the housing body 1 from the external environment. The shape of the cover plate 2 can be adapted to the shape of the housing body 1 to match the housing body 1. The cover plate 2 can be made of a material with a certain hardness and strength (such as an aluminum alloy).

[0042] In one embodiment, the housing body 1 and the cover plate 2 are both made of aluminum, thereby satisfying 0.04≤b / a≤0.98.

[0043] It should be noted that the hardness of the aluminum cover plate 2 is relatively low. To avoid the influence of deformation of the cover plate 2 during the assembly process, a relatively long stepped structure 11 must be set to ensure the confinement effect on the aluminum cover plate 2. In addition, for aluminum, the melting point of the housing body 1 and the cover plate 2 is relatively low. During welding, the welding quality of the housing body 1 and the cover plate 2 is relatively good.Therefore, by further limiting the value range of “b / a”, it is possible to ensure the welding quality of the housing body 1 and the cover plate 2 and the limiting effect of the step structure 11 on the cover plate 2, thereby improving the assembly efficiency of the cover plate 2 and the housing body 1 and improving the positional accuracy of the cover plate 2 mounted on the housing body 1, thereby ensuring the welding reliability of the cover plate 2 and the housing body 1, thereby improving the assembly quality of the cover plate 2 and the housing body 1.

[0044] In a further embodiment, the housing body 1 and the cover plate 2 are both made of steel, wherein 0.02 ≤ b / a ≤ 0.96 is satisfied.

[0045] It should be noted that for steel, the melting point of the housing body 1 and the cover plate 2 is relatively high. During welding, the weld quality of the housing body 1 and the cover plate 2 is relatively poor. Therefore, a thicker housing wall is required to ensure the weld quality. In addition, the hardness of the steel cover plate 2 is relatively high, and the steel cover plate 2 is not easily deformed during the assembly process. Therefore, even if a shorter step structure 11 is adopted, the limit requirement for the steel cover plate 2 can be ensured.Therefore, by further limiting the value range of “b / a”, it is possible to ensure the welding quality of the housing body 1 and the cover plate 2 and ensure the limiting effect of the step structure 11 on the cover plate 2, thereby improving the assembly efficiency of the cover plate 2 and the housing body 1 and improving the positional accuracy of the cover plate 2 mounted on the housing body 1, thereby ensuring the welding reliability of the cover plate 2 and the housing body 1, thereby improving the assembly quality of the cover plate 2 and the housing body 1.

[0046] In one embodiment, as in Fig. 4, the maximum width between the inner edge of the step structure 11 and the outer edge of the step structure 11 is "c", which satisfies 0.2 mm ≤ c ≤ 4 mm. In this arrangement, while ensuring the positioning effect of the step structure 11 on the cover plate 2 to ensure the assembly quality and welding quality of the cover plate 2 and the housing body 1, it is ensured that the housing wall at the open end of the housing body 1 has a sufficient thickness to ensure the structural strength of the housing body 1 and meet the welding requirements of the cover plate 2 and the housing body 1, thereby avoiding the occurrence of problems such as breakage of the welding wire.

[0047] It should be noted that when c>4mm, the width of the step structure 11 is too large, resulting in an excessively large tapered thickness, and the remaining thickness of the housing body 1 is too small, resulting in poor structural strength of the housing body 1 at the open end, and the housing body 1 is prone to deformation or even fracture at the open end. In addition, the excessive length of the tapered portion of the housing wall of the housing body 1 also results in poor welding strength between the cover plate 2 and the housing body 1, resulting in poor welding quality, causing problems such as breakage of the welding wire, and resulting in failure of the assembly of the housing body 1 and the cover plate 2.When c < 0.2 mm, the width of the step structure 11 is too small, and the step structure 11 has insufficient restraining effect on the cover plate 2, which affects the assembly efficiency of the cover plate 2 and the housing body 1, and misalignment of the cover plate 2 and the housing body 1 is easy to occur. Therefore, a higher welding strength between the cover plate 2 and the housing body 1 is required to ensure the connection reliability of the cover plate 2 and the housing body 1. However, if the welding strength between the cover plate 2 and the housing body 1 is insufficient, assembly failure of the housing body 1 and the cover plate 2 is also easy to occur.

[0048] Optionally, the value of “c” can be any of the following values: 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4 mm or a value between any two of the aforementioned values.

[0049] In one embodiment, as in the Fig. 8 and Fig. 9, the cover plate 2 is at least partially embedded in the housing body 1 through the open end, and the side of the cover plate 2 facing the step structure 11 abuts the step structure 11.

[0050] It should be noted that in an embodiment as in Fig. 8, the cover plate 2 has the shape of a flat plate, wherein the cover plate 2 is completely received in the housing mouth portion 13. The inner surface of the cover plate 2 abuts the step structure 11, and the outer surface of the cover plate 2 is substantially flush with the end face of the open end of the housing body 1, so that a weld is performed at the seam between the outer surface of the cover plate 2 and the end face of the open end of the housing body 1. In another embodiment, as shown in Fig. As shown in Figure 9, the cover plate 2 includes, along the thickness direction of the cover plate 2, a cover portion 22 and an embedding portion 21 that are connected to each other. The outer peripheral surface of the cover portion 22 extends out from the outer peripheral surface of the embedding portion 21, so that the outer peripheral surface of the cover plate 2 forms a step shape. The embedding portion 21 is received in the housing mouth portion 13, and the side of the embedding portion 21 remote from the cover portion 22 abuts against the step structure 11. The cover portion 22 is disposed outside the housing body 1. Along the thickness direction of the cover plate 2, the side of the cover portion 22 close to the embedding portion 21 in the step shape abuts against the end surface of the open end of the case body 1. The case body 1 and the cover plate 2 are welded along the outer periphery of the case mouth portion 13 and the outer periphery of the cover portion 22.

[0051] In one embodiment, as in Fig. As shown in Figure 7, the case body 1 and the cover plate 2 are enclosed to form a receiving space 3. The battery also includes a cell provided in the receiving space 3. The cell includes a cell body and a tab portion extending from the cell body, and the cell body is disposed on the side of the step structure 11 remote from the open end. Such an arrangement ensures that the cover plate 2 and the case body 1 can be smoothly assembled, and avoids interference between the cover plate 2 and the cell in the case body 1 and damage to the cell.

[0052] It should be noted that the cell body is arranged on the side of the step structure 11 away from the open end, ie, on the orthogonal projection along the first plate body 15 (ie, the large surface of the cell body), wherein the projection of the cell body and the projection of the step structure 11 do not coincide or overlap.

[0053] It should be noted that the cell comprises a cell body, and the cell body comprises a separator and two electrodes with opposite polarities, namely a positive electrode and a negative electrode. The cell body works by moving metal ions between the positive electrode and the negative electrode. The cycling process of the cell is the process by which metal ions migrate from the positive electrode to the negative electrode and then from the negative electrode to the positive electrode. The cell also includes a tab portion electrically connected to the electrode. The positive tab is electrically connected to the positive electrode, and the negative tab is electrically connected to the negative electrode, and the cell is charged and discharged via the positive tab and the negative tab.The electrode includes a current collector and an active material layer, and the active material layer is coated on the surface of the current collector. If the electrode is a positive electrode, the current collector material can be aluminum, and the active material layer material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. If the electrode is a negative electrode, the current collector material can be copper, and the active material layer material can be carbon or silicon, etc. The separator serves as an insulating layer to prevent short circuits inside the battery caused by contact between the positive and negative electrodes. The separator is also used as a semipermeable layer to prevent the passage of larger molecules and allow small charged ions to pass through.

[0054] Although the embodiments of the present utility model have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

[1] Battery, characterized by that it has: a housing body (1) having an open end at at least one end, wherein a housing wall of the housing body (1) is tapered at the open end to form at least one step structure (11) within the housing body (1); a cover plate (2) blocking the open end and welded to the housing body (1), the cover plate (2) abutting the step structure; wherein the circumference of the housing body (1) at the open end is “a” and the total length of the step structure is “b”, wherein 0.02≤b / a≤0.98 is satisfied. [2] The battery according to claim 1, characterized by that the total length ‘b’ of the step structure (11) satisfies 20 mm ≤ b ≤ 240 mm. [3] Battery according to claim 1 or 2, characterized by that the circumference “a” of the housing body (1) satisfies 200 mm ≤ a ≤ 1000 mm. [4] Battery according to one of claims 1 to 3, characterized bythat the housing body (1) has a quadrangular prism structure. [5] Battery according to claim 4, characterized by that the open end of the housing body (1) has four sides and the step structure (11) is provided corresponding to at least one of the sides. [6] Battery according to one of claims 1 to 5, characterized by that a step structure (11) is provided which is provided continuously along the circumference around the open end. [7] Battery according to one of claims 1 to 6, characterized by that a plurality of step structures (11) are provided which are provided at intervals along the circumference around the open end. [8] Battery according to claim 7, characterized by that the distance between two adjacent step structures (11) is 40 mm to 400 mm. [9] Battery according to one of claims 4 to 8, characterized bythat the open end of the housing body (1) has four corners (12) and the step structure (11) is provided corresponding to at least two of the corners (12), wherein 0.04 ≤ b / a ≤ 0.98 is satisfied. [10] Battery according to claim 9, characterized by that the step structure (11) is provided at two diagonally arranged corners (12), wherein 0.04 ≤ b / a ≤ 0.96 is satisfied. [11] Battery according to claim 9 or 10, characterized by that the step structure (11) is provided corresponding to the four corners (12), wherein 0.04 ≤ b / a ≤ 0.94 is satisfied. [12] Battery according to one of claims 9 to 11, characterized bythat the housing wall of the housing body (1) forms a housing mouth portion (13) at the open end, the housing body (1) further comprises a main body portion (14), the main body portion (14) is connected to the side of the housing mouth portion (13) which is remote from the open end, the step structure (11) is formed on the side of the main body portion (14) which faces the housing mouth portion (13); the main body portion (14) forms a first fillet (141) at the corner (12), the housing mouth portion (13) forms a second fillet (131) at the corner (12), the first fillet (141) and the second fillet (131) are enclosed to form the step structure (11), the radius of the first fillet (141) is "r1", the radius of the second fillet (131) is "r2" and r1≥r2 is satisfied. [13] Battery according to claim 12, characterized bythat the radius “r1” of the first fillet (141) satisfies 0.5 mm ≤ r1 ≤ 5 mm and the radius “r2” of the second fillet (131) satisfies 0.4 mm ≤ r2 ≤ 4.8 mm. [14] Battery according to one of claims 1 to 13, characterized by that the housing body (1) and the cover plate (2) are both made of aluminum, whereby 0.04 ≤ b / a ≤ 0.98 is satisfied. [15] Battery according to one of claims 1 to 14, characterized by that the housing body (1) and the cover plate (2) are both made of steel, whereby 0.02 ≤ b / a ≤ 0.96 is satisfied. [16] Battery according to one of claims 1 to 15, characterized by that the maximum width between the inner edge of the step structure (11) and the outer edge of the step structure (11) is "c", where 0.2 mm ≤ c ≤ 4 mm is satisfied. [17] Battery according to one of claims 1 to 16, characterized bythat the cover plate (2) is at least partially embedded in the housing body (1) through the open end and the cover plate (2) is configured such that it rests against the step structure (11) on a side facing the step structure (11). [18] Battery according to one of claims 1 to 17, characterized by in that the housing body (1) and the cover plate (2) enclose a receiving space (3), the battery further comprises a cell, the cell is provided in the receiving space (3), the cell comprises a cell body and a tab portion extending from the cell body, and the cell body is arranged on a side of the step structure (11) remote from the open end. [19] Battery according to one of claims 1 to 18, wherein the cover plate (2) is welded circumferentially to the housing body (1) at the open end. [20] Battery according to one of claims 1 to 19, wherein the housing body (1) has two opposite first plate bodies (15) and two opposite second plate bodies (16), wherein adjacent plate bodies (15, 16) form a corner (12), wherein the corner (12) has a rounded or rectangular structure, wherein at least one of the first plate body (15), the second plate body (16) and the corner (12) is provided with one of the step structures (11), and wherein the open end has four sides and four corners (12) and a or the step structure (11) is provided corresponding to at least one side and / or corresponding to at least one corner (12).

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