Patent Description:
In the related arts, a battery typically comprises a housing and an electrode assembly provided within the housing. The electrode assembly comprises a jellyroll, a connecting sheet and a tab connected to an end of the jellyroll. The tab and the connecting sheet are usually fixed by ultrasonic welding. Generally, all overlapping areas between the tab and the connecting sheet are welded during welding, so that debris is adhered to edges of the overlapping areas. During the battery charging and discharging process, debris tends to fall off, which may cause a short circuit between positive and negative electrodes, and lead to a serious safety hazard.

<CIT> discloses an energy storage device according to the state of the art.

An object of the present disclosure is to provide an energy storage device and an electrical equipment with improved safety performance.

In order to achieve the above object, the present disclosure provides the following technical solutions.

According to an aspect of the present disclosure, an energy storage device is provided. The energy storage device comprises a housing, a jellyroll, a connecting sheet, and a top cover. The jellyroll and the connecting sheet are received within the housing, and the top cover seals the housing.

The jellyroll is provided with a tab, and the connecting sheet comprises a body part and a side wing part.

The energy storage device further comprises a welding structure. The welding structure is composed of the tab and the side wing part, and the welding structure is formed by welding.

The tab comprises a plurality of tab sheets, a tab sheet of the plurality of tab sheets farthest from the side wing part is a first tab sheet. The welding structure forms a welding area on the first tab sheet.

An area of the welding area is S1, an area of the side wing part is S2, and a projection area of the first tab sheet on a plane where the side wing part is located is S3, wherein:
<NUM> ≤ <NUM>/<NUM> ≤ <NUM>; <NUM> ≤ S1/S3 ≤ <NUM>.

In the embodiment of the present disclosure, after the side wing part of the connecting sheet is attached to the tab, selecting an appropriate area proportion of the welding area can greatly reduce the generation of debris while ensuring the welding strength, thereby reducing the safety hazards of the energy storage device. In addition, using a welding structure composed of the connecting sheet and the tab can avoid from using a protective sheet and thus reduce the cost, remove a procedure of placing the protective sheet, prevent the protective sheet from scratching the tab which may cause the product to be scrapped when the protective sheet is being placed, and greatly improve the welding efficiency.

According to the invention, the welding area comprises a fixing welding area and a guiding welding area, wherein the fixing welding area and the guiding welding area are distributed along a length direction of the side wing part.

A distance between the fixing welding area and the guiding welding area is d1, and a size of the fixing welding area in the length direction of the side wing part is d2, wherein d1/d2 ≤ <NUM>.

In the embodiment of the present disclosure, the fixing welding area and the guiding welding area are provided with a gap between the fixing welding area and the guiding welding area defined, so that the tab and the side wing part may be welded by separate regions (i.e., there are separate welding regions between the tab and the side wing part). The deformation of the tab in the fixing welding area and the guiding welding area can be alleviated by the gap, so as to reduce the deformation amount per unit length during welding of the tab in the length direction of the side wing part and reduce the risk of tearing of the tab.

According to an embodiment of the present disclosure, the side wing part is welded with the tab to form several first welding spots located in the fixing welding area, and several second welding spots located in the guiding welding area.

A gap between the fixing welding area and the guiding welding area is less than a size of the first or second welding spot in the length direction of the side wing part.

In the embodiment of the present disclosure, the distance between the fixing welding area and the guiding welding area is shortened to increase the welding area of the tab and the connecting sheet, thereby further ensuring the welding strength and ensuring the flow guiding effect between the tab and the connecting sheet.

According to an embodiment of the present disclosure, a welding mark area of the first welding spots is smaller than or equal to a welding mark area of the second welding spots.

In the embodiment of the present disclosure, when welding in the fixing welding area, the size of the first welding spot is reduced, thereby reducing the deformation amount of the tab during welding, and reducing the risk of tab tearing during welding. Meanwhile, when welding in the guiding welding area, the size of the second welding spot is increased, thereby ensuring a sufficient contact area between the tab and the side wing part in the guiding welding area, and ensuring the flow guiding effect between the tab and the connecting sheet.

According to the invention, there is an overlapping area between the side wing part and the first tab sheet in a thickness direction of the side wing part.

An area of the fixing welding area is S11, an area of the overlapping area is S4, and a distance between an edge of the fixing welding area and an edge of the overlapping area is L1, wherein <NUM>% ≤ S11/S4 ≤ <NUM>%; and <NUM> ≤ L1 ≤ <NUM>.

According to the present invention, the area of the fixing welding area and edges of the fixing welding area and the side wing part are defined, so as to increase a fixing area of the tab and the connecting sheet in the length direction and a width direction of the side wing part, thereby ensuring the welding stability of the tab and the connecting sheet while effectively reducing the risk of tab tearing.

According to the invention, there is an overlapping area between the side wing part and the first tab sheet in the thickness direction of the side wing part.

An area of the guiding welding area is S12, and an area of the overlapping area is S4, and a distance between an edge of the guiding welding area and an edge of the overlapping area is L2, wherein <NUM>% ≤ S12/S4 ≤ <NUM>%; and <NUM> ≤ L2 ≤ <NUM>.

In the embodiment of the present disclosure, the area of the guiding welding area and edges of the guiding welding area and the side wing part are defined, so as to increase the flow guiding area of the tab and the connecting sheet in the width direction of the side wing, thereby effectively reducing the risk of tab tearing while ensuring a sufficient contact area between the tab and the connecting sheet, and thus ensuring the flow guiding effect between the tab and the connecting sheet.

According to an embodiment of the present disclosure, the plurality of tab sheets are welded with the side wing part to form several first welding spots, and the first welding spots are located in the fixing welding area.

A distance between two adjacent first welding spots is L11, and a size of the first welding spot in a layout direction of the two adjacent first welding spots is L12, wherein L11 < L12.

In the embodiment of the present disclosure, a density of the first welding spots in the fixing welding area is adjusted so as to ensure the stability of welding when the tab and the connecting sheet are fixedly welded.

According to an embodiment of the present disclosure, L11/L12 > <NUM>%.

In the embodiment of the present disclosure, a minimum distance between the two adjacent first welding spots in the fixing welding area is defined to reduce the risk of tab tearing between the adjacent first welding spots.

According to an embodiment of the present disclosure, the plurality of tab sheets are welded with the side wing part to form several second welding spots, and the second welding spots are located in the guiding welding area.

A distance between two adjacent second welding spots is L21, and a size of the second welding spot in a layout direction of the two adjacent second welding spots is L22, wherein L21 < L22.

In the embodiment of the present disclosure, a density of the second welding spots in the guiding welding area is adjusted so as to ensure the flowing effect between the tab and the connecting sheet.

According to an embodiment of the present disclosure, L21/L22 ><NUM>%.

In the embodiment of the present disclosure, a minimum distance between the two adjacent second welding spots in the guiding welding area is defined to reduce the risk of tab tearing between the adjacent second welding spots.

According to an embodiment of the present disclosure, a plurality of welding areas comprise two fixing welding areas located on two sides of the guiding welding area along the length direction of the side wing part.

In the embodiment of the present disclosure, two fixing welding areas are fixedly welded at two ends thereof in the length direction of the side wing part, thereby further ensuring the stability of the relative position between the tab and the connecting sheet before the flow guiding welding. In addition, the welding area is divided into three partition areas, further increasing a distribution range of the three partition areas, increasing the overall fixing area between the tab and the connecting sheet, improving the stability of connection between the tab and the connecting sheet, and increasing the overall flow guiding area of the tab and the connecting sheet.

According to an embodiment of the present disclosure, two fixing welding areas are symmetrically distributed with respect to the guiding welding area.

In the embodiment of the present disclosure, the guiding welding area is positioned and centered between the two fixing welding areas, ensuring the uniformity of flowing between the tab and the connecting sheet, and thereby ensuring the flow guiding effect of the tab and the connecting sheet.

According to an embodiment of the present disclosure, a thickness of the welding structure is H, wherein <NUM> ≤ H ≤ <NUM>.

In the embodiment of the present disclosure, the thickness of the welding structure is defined, avoiding the risk that it is easy to be tore due to a thin welding structure, and thereby ensuring the flow guiding effect between the tab and the connecting sheet; and also avoiding a situation where a thick welding structure occupies a large space inside the housing so that the overall volume of the energy storage device is large.

According to an embodiment of the present disclosure, the welding area comprises a plurality of welding spots, and a depth of the welding spot is S, wherein <NUM> ≤ S ≤ <NUM>.

In the embodiment of the present disclosure, the depth of the welding spot in the welding area is defined to reduce a deformation area of the tab, that is, reduce the deformation amount of the tab, and reduce the risk of tab tearing; and also reduce the risk of unstable welding on the tab and the connecting sheet since the depth of the welding spot is small.

According to an aspect of the present disclosure, an electrical equipment is provided. The electrical equipment comprises an energy storage device as described in the above aspect, and the energy storage device supplies power to the electrical equipment.

In the embodiment of the present disclosure, in combination with the energy storage device as mentioned above, when it is not necessary to provide the protective sheet (i.e., the arrangement of the protective sheet can be omitted), it is beneficial to reduce the weight of the energy storage device, thereby reducing the load on the electrical equipment and improving its performance.

It should be understood that the general description as mentioned above and the detailed description in the following contents are only illustrative and explanatory, and do not limit the present disclosure.

With reference to the accompanying drawings, the exemplary embodiments are described in detail, and the above and other features and advantages of the present disclosure will become more apparent.

The reference numbers are listed as follows:.

The exemplary embodiments will now be described more comprehensively with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in multiple forms and should not be limited to the embodiments described herein; on the contrary, providing these embodiments makes the present disclosure comprehensive and complete, and fully conveys the concept of the exemplary embodiments to those skilled in the art. The same reference numbers in the figures represent the same or similar structures, and thus their detailed descriptions will be omitted.

An embodiment of the present disclosure provides an energy storage device, which may be, but is not limited to, a cell, a battery module, a battery pack, a battery system, etc. When the energy storage device is a cell, it may be a prismatic cell or a cylindrical cell. Next, a prismatic cell is taken as an example of the energy storage device to provide a detailed description of the energy storage device.

<FIG> illustrates an exploded structural schematic view of a cell <NUM> provided in the embodiment of the present disclosure, and <FIG> illustrates a structural schematic view of a tab <NUM> connected to a connecting sheet <NUM> provided in the embodiment of the present disclosure. As shown in <FIG>, the cell <NUM> comprises a housing <NUM>, a jellyroll <NUM>, a connecting sheet <NUM>, and a top cover <NUM>. The jellyroll <NUM> and the connecting sheet <NUM> are received in the housing <NUM>, and the top cover <NUM> seals the housing <NUM>. The jellyroll <NUM> is provided with a tab <NUM>. The connecting sheet <NUM> comprises a body part <NUM> and a side wing part <NUM>. The cell <NUM> further comprises a welding structure composed of the tab <NUM> and the side wing part <NUM>. The welding structure is formed by welding. In addition, the top cover <NUM> is provided with an electrode column, and the electrode column is welded to the body part <NUM> of the connecting sheet <NUM> to form another welding structure.

The tab <NUM> provided on the jellyroll <NUM> is composed of stacked tab sheets. As shown in <FIG>, or <FIG>, after the tab <NUM> is welded to a side of the connecting sheet <NUM>, a welding area <NUM> is formed on one tab sheet (i.e., a first tab sheet <NUM>) of the plurality of tab sheets farthest from the side wing part <NUM>. That is, the welding structure formed by welding the tab <NUM> with the side wing part <NUM> of the connecting sheet <NUM> forms the welding area <NUM> on the first tab sheet <NUM>.

In the embodiment of the present disclosure, the welding area <NUM> is directly formed on the first tab sheet <NUM>. That is, when the tab <NUM> is welded with the connecting sheet <NUM>, it is not necessary to provide the protective sheet, thereby reducing the cost and preventing the protective sheet from scratching the tab <NUM>, which may cause the cell to be scrapped when the protective sheet is placed. In addition, a procedure of placing the protective sheet is omitted to simplify the welding process of the tab <NUM> and the connecting sheet <NUM>, and greatly improve the welding efficiency of the tab <NUM> and the connecting sheet <NUM>.

As shown in <FIG>, the cell <NUM> comprises two connecting sheets <NUM> (a positive connecting sheet and a negative connecting sheet) received within the housing <NUM>. An end of the jellyroll <NUM> is provided with two tabs <NUM> (a positive tab and a negative tab) (not shown). The top cover <NUM> is provided with two electrode columns (a positive column and a negative column). The side wing part <NUM> of the positive connecting sheet is welded to the positive tab, and the body part <NUM> of the positive connecting sheet is connected with the positive column. The side wing part <NUM> of the negative connecting sheet is welded to the negative tab, and the body part <NUM> of the negative connecting sheet is connected with the negative column.

Optionally, as shown in <FIG>, the cell <NUM> comprises two jellyrolls <NUM> received within the housing <NUM>. At this time, the connecting sheet <NUM> comprises two side wing parts <NUM>, and the tabs <NUM> of the two jellyrolls <NUM> having the same polarity are respectively welded to the two side wing parts <NUM> of the connecting sheet <NUM>.

Optionally, an end surface of the jellyroll <NUM> faces towards the top cover <NUM>, and the end facing towards the top cover <NUM> is provided with two tabs <NUM>. Alternatively, a centerline of the end surface of the jellyroll <NUM> is parallel to a plane where the top cover <NUM> is located, and each of the two ends of the jellyroll <NUM> is provided with one tab <NUM>.

Optionally, for the welding structure formed by welding the tab <NUM> and the side wing part <NUM> of the connecting sheet <NUM>, a thickness of the welding structure is H, wherein <NUM> ≤ H ≤ <NUM>. In this way, the thickness of the welding structure is defined, avoiding the risk that the connecting sheet <NUM> and the tab <NUM> may be easily tore due to a thin welding structure, thereby ensuring the stability of connection between the tab <NUM> and the connecting sheet <NUM> and the flow guiding effect. A situation where a thick welding structure occupies a larger space inside the housing <NUM> is avoided, so that the overall volume of the energy storage device is large.

The thickness of the welding structure refers to a thickness of the side wing part <NUM> of the connecting sheet <NUM> in the welding area <NUM>, and a total thickness of the plurality of tab sheets. In this way, the thickness of the welding structure can be adjusted by changing the number of layers of the tab sheets and the thickness of the side wing part <NUM>, so that the thickness H of the welding structure satisfies a relationship of <NUM> ≤ H ≤ <NUM>.

Optionally, when the tab <NUM> and the side wing part <NUM> of the connecting sheet <NUM> are welded, a plurality of welding spots are formed in the welding area <NUM> on the first tab sheet <NUM>, and a depth of the welding spot is S, i.e., <NUM> ≤ S ≤ <NUM>. In this way, a maximum depth of the welding spot is defined to reduce the deformation area of the tab <NUM>, that is, reduce the deformation amount of the tab <NUM>, thereby reducing the risk of tearing of the tab <NUM>. Meanwhile, a minimum depth of the welding spot is defined, ensuring the welding stability between the tab <NUM> and the side wing part <NUM> of the connecting sheet <NUM>, and avoiding the risk that the tab <NUM> falls off the side wing part <NUM>.

The plurality of welding spots within the welding area <NUM> maybe distributed in an arbitrary manner, such as in an array of m×n, where m and n both are integers greater than or equal to <NUM>, m is the number of welding spots in a length direction O1 of the side wing part <NUM>, and n is the number of welding spots in a width direction O2 of the side wing part <NUM>.

Optionally, the welding spot within the welding area <NUM> may be circular, rectangular, or rhombic, etc. For example, the welding spot is circular, the welding spot is square, or the welding spot is rhombic. Of course, the welding spot may also be elliptical, parallelogram, etc., depending on a shape of a welding head of an ultrasonic welding machine. The shapes of the welding spots according to the present disclosure are cross-sectional shapes of the welding spots respectively, that is, projection shapes of the welding spots in a thickness direction of the connecting sheet <NUM>.

Optionally, welding mark areas of the welding spots within the welding area <NUM> may be the same or different. For example, each of the plurality of welding spots within the welding area <NUM> is circular with a diameter of <NUM>; or each of the welding spots is square with a side length of <NUM>; or each of the welding spots is rhombic with a side length of <NUM>.

Optionally, a distance between two adjacent welding spots within the welding area <NUM> is less than or equal to a size of the welding spot in a layout direction of the two adjacent welding spots. In this way, a distribution density of the welding spots within the welding area <NUM> is adjusted to ensure the stability of the welding between the tab <NUM> and the connecting sheet <NUM>, while reducing the risk of tearing of the tab <NUM>.

For example, when a circular welding spot with a diameter of <NUM>, the distance between two adjacent welding spots within the welding area <NUM> is less than <NUM>. When a square welding spot with a side length of <NUM> is taken as an example, the distance between two adjacent welding spots within the welding area <NUM> is less than <NUM>.

According to the invention, as shown in <FIG>, an area of the welding area <NUM> is S1, an area of the side wing part <NUM> is S2, and a projection area of the first tab sheet <NUM> on a plane where the side wing part <NUM> is located is S3, wherein <NUM> ≤ S1/S2 ≤ <NUM>; and <NUM> ≤ S1/S3 ≤ <NUM>.

In the embodiment of the present disclosure, it is not necessary to provide the protective sheet. After the side wing part of the connecting sheet is attached to the tab, selecting an appropriate area proportion of the welding area can greatly reduce the generation of debris while ensuring the welding strength, thereby reducing the safety hazards of the energy storage device. In addition, selecting the appropriate area proportion of the welding area can also ensure the flow guiding effect between the tab and the side wing part of the connecting sheet, thereby ensuring the electrical performance of the energy storage device.

For the assembled cell <NUM>, the first tab sheet <NUM> is usually in a bended state. That is, after the first tab sheet <NUM> is welded with the side wing part <NUM> of the connecting sheet <NUM>, the first tab sheet <NUM> is bent along a bending line L as shown in <FIG>, or <FIG>, so as to facilitate to seal the top cover <NUM> onto the housing <NUM>. After the first tab sheet <NUM> is bent along the bending line L, the first tab sheet <NUM> comprises a vertical part (which is directly connected to the jellyroll <NUM>) perpendicular to a plane where the side wing part <NUM> is located, and a plane part (which is connected to the jellyroll <NUM> through the vertical part) parallel to the plane where the side wing part <NUM> is located. In this way, a projection area of the first tab sheet <NUM> on the plane where the side wing part <NUM> is located is an area of the plane part comprised in the first tab sheet <NUM>.

In the embodiment of the present disclosure, the welding area <NUM> may be a continuous area or separated areas spaced apart from each other.

In some embodiments, as shown in <FIG>, or <FIG>, the welding area <NUM> comprises a fixing welding area <NUM> and a guiding welding area <NUM>. The fixing welding area <NUM> and the guiding welding area <NUM> are distributed along the length direction O1 of the side wing part <NUM>.

In this way, the fixing welding area <NUM> and the guiding welding area <NUM> are provided so that the tab <NUM> and the side wing part <NUM> may be welded by separate regions, so as to reduce welding areas of separated areas between the tab <NUM> and the side wing part <NUM>. Thus, the deformation amount per unit length during the welding of the tab <NUM> in the length direction O1 of the side wing part <NUM> is reduced, and thereby reducing the risk of tearing of the tab <NUM>. In addition, the fixing welding area <NUM> and the guiding welding area <NUM> are separated, increasing the overall welding area <NUM> between the tab <NUM> and the connecting sheet <NUM>, improving the stability of connection between the tab <NUM> and the connecting sheet <NUM>, and increasing the overall flow guiding area between the tab <NUM> and the connecting sheet <NUM>.

An area of the fixing welding area <NUM> is smaller than an area of the guiding welding area <NUM>, so that a small area welding is provided in the fixing welding area <NUM> to achieve pre-fixation of the tab <NUM> and the connecting sheet <NUM>. Then, a large area welding is provided in the guiding welding area <NUM> to ensure the flow guiding effect between the tab <NUM> and the connecting sheet <NUM>, thereby reducing the risk of tearing of the tab <NUM> during welding.

For the welding of the tab <NUM> with the side wing part <NUM> of the connecting sheet <NUM>, as shown in <FIG>, or <FIG>, several first welding spots <NUM> located in the fixing welding area <NUM> and several second welding spots <NUM> located in the guiding welding area <NUM> may be formed.

The number of the first welding spots <NUM> and the number of the second welding spots <NUM> may be same or different. When the number of the first welding spots <NUM> is same as the number of the second welding spots <NUM>, a welding mark area of the first welding spots <NUM> is smaller than a welding mark area of the second welding spots <NUM>, so as to ensure that the area of the fixing welding area <NUM> is smaller than the area of the guiding welding area <NUM>.

For example, the number of first welding spots <NUM> is different from the number of second welding spots <NUM>. As shown in <FIG>, the fixing welding area <NUM> comprises eight first welding spots <NUM> distributed in an array of <NUM>×<NUM>, and the guiding welding area <NUM> comprises sixteen second welding spots <NUM> distributed in an array of <NUM>×<NUM>. Alternatively, as shown in <FIG>, the fixing welding area <NUM> comprises four first welding spots <NUM> distributed in an array of <NUM>×<NUM>, and the guiding welding area <NUM> comprises eighteen second welding spots <NUM> distributed in an array of <NUM>×<NUM>.

The shape and distribution of the first welding spots <NUM> and the second welding spots <NUM> may refer to the shape and distribution of the welding spots as mentioned above, not limited in the embodiment of the present disclosure. The shape of the first welding spot <NUM> and the shape of the second welding spot <NUM> may be the same or different.

For example, the shape of the first welding spot <NUM> is same as that of the second welding spot <NUM>. As shown in <FIG> or <FIG>, the first welding spot <NUM> and the second welding spot <NUM> are both circular. Alternatively, as shown in <FIG>, the first welding spot <NUM> and the second welding spot <NUM> are both square, or the first welding spot <NUM> and the second welding spot <NUM> are both rhombic.

The welding mark area of the first welding spot <NUM> and the second welding spot <NUM> may be equal or not equal. When the welding mark area of the first welding spot <NUM> and the welding mark area of the second welding spot <NUM> are equal, the number of the first welding spots <NUM> is less than the number of the second welding spots <NUM> to ensure that the area of the fixing welding area <NUM> is smaller than the area of the guiding welding area <NUM>. When the welding mark area of the first welding spots <NUM> is smaller than that of the second welding spots <NUM>, the size of the first welding spot <NUM> is reduced when welding in the fixing welding area <NUM>, thereby reducing the deformation amount of the tab <NUM> during welding, and reducing the risk of tearing of the tab <NUM> during welding in the fixing welding area <NUM>. Meanwhile, the size of the second welding spot <NUM> is increased when welding in the guiding welding area <NUM> to ensure that the tab <NUM> and the side wing part <NUM> have sufficient contact area in the guiding welding area <NUM>, thereby ensuring the flow guiding effect between the tab <NUM> and the connecting sheet <NUM>.

For example, the welding mark area of the first welding spot <NUM> is equal to the welding mark area of the second welding spot <NUM>. As shown in <FIG>, the first welding spot <NUM> and the second welding spot <NUM> are both circular with a diameter of <NUM>. Alternatively, as shown in <FIG>, the first welding spot <NUM> and the second welding spot <NUM> are both square with a side length of <NUM>. For another example, the welding mark area of the first welding spot <NUM> is different from the welding mark area of the second welding spot <NUM>. , as shown in <FIG>, the first welding spot <NUM> is circular with a diameter of <NUM>, while the second welding spot <NUM> is circular with a diameter of <NUM>. The welding mark area according to the present disclosure is a cross-sectional area of the welding spot, that is, a projection area of the welding spot in the thickness direction of the connecting sheet.

In some embodiments, as shown in <FIG>, for the first welding spots <NUM> within the fixing welding area <NUM>, a distance between adjacent first welding spots <NUM> is L11, and a size of the first welding spot <NUM> in a layout direction of the adjacent first welding spots <NUM> is L12, wherein L11 < L12. In this way, the density of the first welding spots <NUM> in the fixing welding area <NUM> is adjusted in the length direction O1 and the width direction O2 of the side wing part <NUM>, thereby ensuring the welding stability between the tab <NUM> and the connecting sheet <NUM>.

Furthermore, as shown in <FIG>, the distance between the two adjacent first welding spots <NUM> is L11, and the size of the first welding spot <NUM> in the layout direction of the two adjacent first welding spots <NUM> is L12, wherein L11/L12 > <NUM>%. In this way, a minimum distance between the two adjacent first welding spots <NUM> in the fixing welding area <NUM> is defined in the length direction O1 and the width direction O2 of the side wing part <NUM>, thereby avoiding a situation where the two adjacent first welding spots <NUM> are too close to cause a large deformation amount of the tab <NUM> within a unit size. Thus, the risk of tearing of the tab <NUM> is reduced.

In some embodiments, as shown in <FIG>, for the second welding spots <NUM> in the guiding welding area <NUM>, a distance between the adjacent two second welding spots <NUM> is L21, and a size of the second welding spot <NUM> in a layout direction of the adjacent two second welding spots <NUM> is L22, wherein L21 < L22. In this way, the density of the second welding spots <NUM> in the guiding welding area <NUM> is adjusted in the length direction O1 and the width direction O2 of the side wing part <NUM>, thereby ensuring the flowing effect between the tab <NUM> and the connecting sheet <NUM>.

Furthermore, as shown in <FIG>, the distance between the two adjacent second welding spots <NUM> is L21, and the size of the second welding spot <NUM> in the layout direction of the two adjacent second welding spots <NUM> is L22, wherein L21/L22 > <NUM>%. In this way, a minimum distance between two adjacent second welding spots <NUM> in the guiding welding area <NUM> is defined in the length direction O1 and width direction O2 of the side wing part <NUM>, thereby avoiding a situation where the adjacent second welding spots <NUM> are too close to cause a large deformation amount of the tab <NUM> within a unit size. Thus, the risk of tearing of the tab <NUM> is reduced.

In some embodiments, as shown in <FIG>, or <FIG>, the plurality of welding areas <NUM> comprise two fixing welding areas <NUM>. The two fixing welding areas <NUM> are located on both sides of the guiding welding area <NUM> along the length direction O1 of the side wing part <NUM>. In this way, the two fixing welding areas <NUM> are fixedly welded at both ends of the side wing part <NUM> in the length direction O1, thereby further ensuring the stability of the relative position between the tab <NUM> and the connecting sheet <NUM> before the flow guiding welding. In addition, the welding area <NUM> is further divided into three partition areas, further increasing a distribution range of the three partition areas, thereby increasing the overall fixing area between the tab <NUM> and the connecting sheet <NUM>. Thus, the stability of the connection between the tab <NUM> and the connecting sheet <NUM> is improved, and the overall flow guiding of the tab <NUM> and the connecting sheet <NUM> is increased.

Optionally, two fixing welding areas <NUM> are symmetrically distributed with respect to the guiding welding area <NUM>, that is, distances between the two fixing welding areas <NUM> and the guiding welding area <NUM> are equal. In this way, the overall uniformity of the flow guiding in the flow guiding area between the tab <NUM> and the connecting sheet <NUM> can be ensured, thereby ensuring the flow guiding effect between the tab <NUM> and the connecting sheet <NUM>.

In some embodiments, as shown in <FIG>, a distance between the fixing welding area <NUM> and the guiding welding area <NUM> is d1, and a size of the fixing welding area <NUM> in the length direction of the side wing part <NUM> is d2, wherein d1/d2 ≤ <NUM>. In this way, when welding the tab <NUM> and the connecting sheet <NUM>, a gap between the fixing welding area <NUM> and the guiding welding area <NUM> is defined. Thus, the deformation of the tab <NUM> in the fixing welding area <NUM> and the guiding welding area <NUM> can be alleviated through the gap, so as to reduce the deformation amount of the tab <NUM> per unit length in the length direction O1 of the side wing part <NUM>, thereby further reducing the risk of tearing of the tab <NUM> during welding.

Optionally, combined with the above-mentioned that the fixing welding area <NUM> comprises the first welding spot <NUM>, the guiding welding area <NUM> comprises the second welding spot <NUM>, the gap between the fixing welding area <NUM> and the guiding welding area <NUM> is less than the size of the first welding spot <NUM> or the second welding spot <NUM> in the length direction O1 of the side wing part <NUM>. In this way, the distance between the fixing welding area <NUM> and the guiding welding area <NUM> is shortened to increase the welding area between the tab <NUM> and the connecting sheet <NUM>, thereby further ensuring the welding strength and ensuring the flow guiding effect between the tab <NUM> and the connecting sheet <NUM>.

In the embodiment of the present disclosure, there is an overlapping area between the side wing part <NUM> and the first tab sheet <NUM> in the thickness direction of the side wing part <NUM>. In this way, when welding the tab <NUM> and the connecting sheet <NUM>, the welding area <NUM> on the first tab sheet <NUM> is located within the overlapping area between the side wing part <NUM> and the first tab sheet <NUM>. Combined with the above mentioned that the welding area <NUM> comprises the fixing welding area <NUM> and the guiding welding area <NUM> as described above, as shown in <FIG>, or <FIG>, both the fixing welding area <NUM> and the guiding welding area <NUM> are located in the overlapping area between the side wing part <NUM> and the first tab sheet <NUM>.

According to the invention, for the fixing welding area <NUM>, as shown in <FIG>, an area of the fixing welding area <NUM> is S11, and an area of the overlapping area is S4, wherein <NUM>% ≤ S11/S4 ≤ <NUM>%. In this way, the area of the fixing welding area <NUM> is defined, ensuring the stability of the welding between the tab <NUM> and the connecting sheet <NUM> during the fixing welding process, and also avoiding the large deformation of the tab <NUM> per unit area caused by the large area of the fixing welding area <NUM>, thereby avoiding the tearing of the tab <NUM>.

In addition, as shown in <FIG>, taking the length direction along the side wing part <NUM> as an example, a distance between an edge of the fixing welding area <NUM> and an edge of the overlapping area is L1, wherein <NUM> ≤ L1 ≤ <NUM>. Alternatively, a distance between an edge of the fixing welding area <NUM> and an edge of the overlapping area along the width direction of the side wing part <NUM> may be L1; or the distance between the edge of the fixing welding area <NUM> and the edge of the overlapping area along the length direction or the width direction of the side wing part <NUM> is L1. In this way, the edges of the fixing welding area <NUM> and the side wing part <NUM> are defined, so as to increase the fixing area between the tab <NUM> and the connecting sheet <NUM> in the side wing part <NUM> along the length direction O1 and the width direction O2, and increase the welding size of the tab <NUM> and the connecting sheet <NUM> in the length direction O1 and the width direction O2 of the side wing part <NUM>, thereby effectively reducing the risk of tearing of the tab <NUM>, that is, ensuring the stability of the welding between the tab <NUM> and the connecting sheet <NUM> while effectively reducing the risk of tearing of the tab <NUM>. For example, in the width direction O2 of the side wing part <NUM>, the distance between the edge of the fixing welding area <NUM> and the edge of the overlapping area is <NUM>; and in the length direction O1 of the side wing part <NUM>, the distance between the edge of the fixing welding area <NUM> and the edge of the overlapping area is <NUM>.

In some embodiments, for the guiding welding area <NUM>, as shown in <FIG>, an area of the guiding welding area <NUM> is S12, and the area of the overlapping area is S4, wherein <NUM>% ≤ S12/S4 ≤ <NUM>%. In this way, the area of the guiding welding area <NUM> is defined to ensure sufficient contact area between the tab <NUM> and the connecting sheet <NUM> during the flow guiding welding, thereby ensuring the flow guiding effect between the tab <NUM> and the connecting sheet <NUM>, and further improving the stability of the welding of the tab <NUM> and the connecting sheet <NUM>.

In addition, as shown in <FIG>, along the width direction of the side wing part <NUM>, the distance between the edge of the guiding welding area <NUM> and the edge of the overlapping area is L2, wherein <NUM> ≤ L2 ≤ <NUM>. In this way, the edges between the guiding welding area <NUM> and the side wing part <NUM> are defined to increase the welding size between the tab <NUM> and the connecting sheet <NUM> in the width direction O2 of the side wing part <NUM>, thereby effectively reducing the risk of tearing of the tab <NUM>. For example, in the width direction O2 of the side wing part <NUM>, the distance between the edge of the guiding welding area <NUM> and the edge of the overlapping area is <NUM>.

The invention further provides an electrical equipment, which may be a vehicle, an energy storage container, etc. The electrical equipment comprises the energy storage device as described in the above embodiments, which is used to supply power to the electrical equipment. In this way, in combination with the aforementioned energy storage device, the safety hazards of the energy storage device can be reduced, while the safety of using the electrical equipment is improved. When it is not necessary to provide the protective sheet, it is beneficial to reduce the weight of the energy storage device, thereby reducing the load on the electrical equipment and improving its performance.

In the embodiment of the present disclosure, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise specified. The terms "install", "interconnect", "connect", "fix" and other terms should be understood in a broad sense. For example, "connect" may refer to a fixed connection, a detachable connection, or an integrated connection; "interconnect" may refer to direct interconnection or indirectly interconnection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood based on specific circumstances.

In the description of the embodiments of the present disclosure, it should be understood that the terms "above", "under", "left", "right", "front", "back" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the attached drawings, only for the convenience of describing the embodiments and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, It cannot be understood as a limitation on the embodiments.

In the description of the specification, the terms "one embodiment", "some embodiments", "specific embodiments", etc. refer to the specific features, structures, materials, or features described in conjunction with the embodiment or example being comprised in at least one embodiment or example of the embodiment. In the specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or features described can be combined in an appropriate manner in any one or more embodiments or examples.

Claim 1:
An energy storage device, comprising a housing (<NUM>), a jellyroll (<NUM>), a connecting sheet (<NUM>), and a top cover (<NUM>), the jellyroll (<NUM>) and the connecting sheet (<NUM>) are received within the housing (<NUM>), and the top cover (<NUM>) seals the housing (<NUM>), wherein
the jellyroll (<NUM>) is provided with a tab (<NUM>), and the connecting sheet (<NUM>) comprises a body part (<NUM>) and a side wing part (<NUM>);
the energy storage device further comprises a welding structure, which is composed of the tab (<NUM>) and the side wing part (<NUM>), and is formed by welding;
the tab (<NUM>) comprises a plurality of tab sheets, a tab sheet of the plurality of tab sheets farthest from the side wing part (<NUM>) is a first tab sheet (<NUM>), the welding structure forms a welding area (<NUM>) on the first tab sheet (<NUM>); characterized in that
an area of the welding area (<NUM>) is S1, an area of the side wing part (<NUM>) is S2, and a projection area of the first tab sheet (<NUM>) on a plane where the side wing part (<NUM>) is located is S3, wherein <NUM> ≤ <NUM>/<NUM> ≤ <NUM>, <NUM> ≤ S1/S3 ≤ <NUM>;
in a thickness direction of the side wing part (<NUM>), there is an overlapping area between the side wing part (<NUM>) and the first tab sheet (<NUM>), the welding area (<NUM>) comprises a fixing welding area (<NUM>) and a guiding welding area (<NUM>) located in the overlapping area, and the fixing welding area (<NUM>) and the guiding welding area (<NUM>) are distributed along a length direction of the side wing part (<NUM>);
an area of the fixing welding area (<NUM>) is S11, an area of the guiding welding area (<NUM>) is S12, and an area of the overlapping area is S4, wherein <NUM>% ≤ S11/S4 ≤ <NUM>% and <NUM>% ≤ S12/S4 ≤ <NUM>%.