Battery cell and battery

Abstract

The utility model discloses a battery cell and a battery. The battery cell comprises a first pole piece, the first pole piece comprises a first current collector and a first active layer, the first current collector comprises a coating area and an empty foil area, and the coating area is coated with the first active layer; the first pole piece is provided with a plurality of first protruding parts and a plurality of first notches, and the empty foil area is arranged on the first current collector at the part where the first protruding parts are located; the first pole piece comprises a plurality of first bending parts which are stacked in the third direction; the plurality of second pole pieces, the first bending parts and the second pole pieces are sequentially stacked in the third direction, each second pole piece is provided with a second sub-tab, and the projection of the second sub-tab in the third direction at least partially coincides with the projection of the first notch; the first bending part and the second pole piece are separated by the diaphragm; and a first electrode adapter and a second electrode adapter, the first electrode adapter is electrically connected with the empty foil area, and the second electrode adapter is electrically connected with the second sub-tab. The battery cell disclosed by the utility model is beneficial to increasing the energy density of the battery cell.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery field especially relates to a battery cell and battery. BACKGROUND

[0002] Lithium ion battery becomes the main power source of consumer electronics and electric vehicles due to many advantages. With the increasing demand of people, lithium ion battery gradually develops to fast charging, long life, high energy density and high safety.

[0003] In order to improve the energy density of lithium ion battery, the welding plane of the soft tab and the hard tab of the multi-tab battery and the laminated battery is often bent to the thickness direction of the battery cell to reduce the three-dimensional size of the battery. The welding structure of the soft tab and the hard tab occupies a part of the head space of the battery cell. In order to utilize the space, the battery of the prior art protrudes the non-tab part in the head space to increase the volumetric energy density of the battery. However, the conventional laminated battery needs to occupy a part of space for the positive tab and the negative tab, and the non-tab part in the head space of the battery cell is less, which has limited effect on the improvement of the energy density of the battery. SUMMARY

[0004] The utility model aims at at least solves one of the prior art technical problems. For this purpose, one object of the utility model is to provide a battery cell and battery. By forming the first tab of the battery cell into an integral structure, only one empty foil area connected with the first adapter can be arranged on the first tab. In this way, the corresponding positions of the plurality of first bending parts to the empty foil area can be coated with the first active layer after the first tab is bent, thereby increasing the energy density of the battery cell.

[0005] The utility model discloses a first aspect, the embodiment of utility model provides a kind of electric core, comprising: first pole piece, the first pole piece includes first current collector and first active layer, the first current collector includes coating area and empty foil area, the coating area is coated with the first active layer;The first pole piece is provided with along the second direction staggered arrangement multiple first protruding parts and multiple first notches in one end along the first direction, the first direction is perpendicular to the second direction, the empty foil area is set on the first current collector in the portion where the first protruding part is located;The first pole piece includes multiple first bending parts arranged in the third direction, multiple the first bending parts are connected with other the first bending parts respectively along the two ends of the second direction, each the first notch is set in one of first bending parts, and the projection of multiple the first notches in third direction overlaps;Multiple second pole pieces, the first bending part and second pole piece are sequentially stacked along the third direction, each the second pole piece has second sub tab along the first end of the first direction, the projection of the second sub tab in the third direction and the projection of the first notch in the third direction at least partially coincide;Diaphragm, the first bending part and the second pole piece are separated by the diaphragm;First electrode adapter and second electrode adapter, the first electrode adapter is electrically connected with the empty foil area, the second electrode adapter is electrically connected with the second sub tab, and at least part of structure of the second electrode adapter is located in the first notch.

[0006] The utility model discloses an electric core, wherein the first pole piece can be regarded as a plurality of same polarity pole piece monomers continuous connection, in the prior art stacked core type electric core, the pole piece of same polarity is set in parts, and the structure connected with corresponding electrode adapter is needed on each pole piece, and the part connected with electrode adapter on pole piece does not have active layer, compared with this, the first pole piece of the embodiment is integral structure, only needs to have the empty foil area connected with first electrode adapter, the region of non-empty foil area on first pole piece can all be coated with first active layer, and the coating area of active layer on the pole piece of prior art is larger, and the energy density of battery made of the pole piece of the embodiment is larger.

[0007] In addition, the first pole piece is repeatedly bent to form a plurality of first bending parts stacked along a third direction, and the second pole piece is arranged in the interval of the two first bending parts along the third direction, thereby forming a structure similar to a stacked core. In the prior art, a notch is arranged at the corresponding end position of the positive pole piece, the negative pole piece and the separator of the roll core type battery cell to accommodate the tab and increase the coating area of the active layer, thereby improving the energy density of the battery. Compared with the prior art, the second pole piece of the battery cell does not have a winding bending area, and the contact area between the first bending part is larger than the contact area between the positive pole piece and the negative pole piece of the roll core type battery cell. While increasing the energy density of the battery cell, the transmission path between the electrons and the ions is shorter, and the rate performance is better.

[0008] In some embodiments, the width H of the first pole piece along the first direction satisfies: 10mm≤H≤200mm; and / or, the length W of the first pole piece along the second direction satisfies: 30mm≤W≤2000mm.

[0009] According to some embodiments of the present application, the length D1 of the empty foil area along the first direction satisfies: 0.5mm≤D1≤H; and / or, the width W1 of the empty foil area along the second direction satisfies: 2mm≤W1≤20mm.

[0010] In some embodiments, the depth D2 of the first notch along the first direction satisfies: 0.1mm≤D2≤10mm; and / or, the width W2 of the first notch along the second direction satisfies: 2mm≤W2≤20mm.

[0011] According to some embodiments of the present application, the empty foil area is located on the first current collector at the part where the first protruding part is arranged along the second direction. In the first protruding part other than the first protruding part where the empty foil area is located, the width W3 of one of any two adjacent first protruding parts satisfies: 0≤W3≤50mm, and the width W4 of the other satisfies: 20≤W4≤100mm.

[0012] In some embodiments, the separator is two, and the two separators are respectively compounded on both sides of the first pole piece.

[0013] According to some embodiments of the present application, the separator has a second notch matched with the first notch, the depth of the second notch along the first direction is D3, and 0≤D3≤9.5mm, and / or the width of the second notch along the second direction is W5, and 1.5mm≤W5≤19mm.

[0014] According to some embodiments of the present application, the diaphragm has a second notch matched with the first notch, a depth of the second notch along the first direction is D3, 0≤D3≤9.5mm, and / or, a width of the second notch along the second direction is W6, 3mm≤W6≤38mm, and / or, a distance between two adjacent second notches along the second direction is W7, 20mm≤W7≤100mm.

[0015] According to some embodiments of the present application, an edge of the diaphragm along the circumferential direction covers more than an edge of the first pole piece along the circumferential direction, an edge of the diaphragm without the second notch exceeds an edge of the first bending part without the first notch to form a first extension part, a width L1 of the first extension part satisfies: 0.2mm≤L1≤2mm; and / or, an edge of the second notch along the second direction exceeds a corresponding edge of the first notch along the second direction to form a second extension part, a width L2 of the second extension part satisfies: 0.2mm≤L2≤3mm; and / or, an edge of the second notch along the first direction exceeds a corresponding edge of the first notch along the first direction to form a third extension part, a width L3 of the third extension part satisfies: 0.5mm≤L3≤3mm.

[0016] In some embodiments, the empty foil area has a first welding mark formed by welding with the first electrode adapter, and the battery cell further comprises: a welding mark protection glue covering at least the first welding mark.

[0017] In some embodiments, a tab glue is further included, surfaces of the first electrode adapter and the second electrode adapter are covered with the tab glue, and along the first direction, a distance D4 between the tab glue and the first bending part satisfies: 0≤D4≤2mm.

[0018] In some embodiments, a plurality of the second sub-tabs are stacked along the third direction to form a second tab, the second tab is welded with the second electrode adapter to form a second welding mark, and the second electrode adapter extends along the first direction.

[0019] According to some embodiments of the present application, along the first direction, a distance D5 between the second welding mark and an edge of the diaphragm at one end of the diaphragm facing the first notch along the first direction satisfies: 0≤D5≤8mm.

[0020] In some embodiments, the second electrode adapter has a bending part and a body part formed by bending, the bending part extends along the third direction, the body part extends along the first direction, and a plurality of the second sub-tabs are welded with a side of the bending part facing outside the first notch to form a second welding mark.

[0021] According to some embodiments of the present application, along the first direction, the distance between the second welding mark and the edge of the diaphragm facing the first notch is D6, 0≤D6≤3mm.

[0022] In some embodiments, the diaphragm is a plurality, the diaphragm is arranged on both sides of each second pole piece, and the diaphragm is combined with the second pole piece.

[0023] In a second aspect, the embodiments of the present application further provide a battery, comprising:

[0024] An outer film shell; the above-mentioned battery cell, the outer film shell covers the battery cell.

[0025] The battery of the present application, due to the use of the above-mentioned battery cell, increases the volume of the non-tab part of the head space of the battery cell, improves the energy density of the battery, and prolongs the endurance time of the battery.

[0026] The additional aspects and advantages of the present application will be partially given in the following description, some will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1 is a structural schematic view of the first pole piece of the battery cell of the present application embodiment;

[0029] Figure 2 is one of the structural schematic views of the battery cell of the present application embodiment 1;

[0030] Figure 3 is Figure 2 is a sectional view of A-A in FIG. 8;

[0031] Figure 4 is a structural schematic view of the connection between the first electrode adapter and the first pole piece of the battery cell of the present application embodiment 1;

[0032] Figure 5 is a structural schematic view of the combination of the first pole piece and the diaphragm of the battery cell of the present application embodiment 1;

[0033] Figure 6 is the second structural schematic view of the battery cell of the present application embodiment 1;

[0034] Figure 7 is a structural schematic view of the battery cell of the present application embodiment 2;

[0035] Figure 8is a structure schematic view of the first pole piece and the diaphragm of the battery cell of the embodiment 2 of the utility model;

[0036] Figure 9 is a structure schematic view of the battery cell of the embodiment 3 of the utility model;

[0037] Figure 10 is Figure 9 is a sectional structure schematic view at B-B of the utility model;

[0038] Figure 11 is a structure schematic view of the battery cell of the embodiment 4 of the utility model;

[0039] Figure 12 is Figure 11 is a sectional structure schematic view at C-C of the utility model.

[0040] Reference signs:

[0041] 100-first pole piece;

[0042] 110-first current collector;111-coating area;112-empty foil area;113-first protruding part;114-first notch;

[0043] 200-battery cell;

[0044] 211-first bending part;

[0045] 220-second pole piece;221-second sub-pole lug;

[0046] 230-diaphragm;231-second notch;232-first extension part;233-second extension part;234-third extension part;

[0047] 240-first electrode adapter;241-first welding mark;

[0048] 250-second electrode adapter;250a-bending part;250b-body part;251-second welding mark;

[0049] 270-pole lug rubber. DETAILED DESCRIPTION

[0050] The embodiments of the utility model are described in detail below, the examples of the embodiments are shown in the drawings, wherein the same or similar signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the utility model, and can not be understood as the limitation of the utility model.

[0051] In order to improve the energy density of the lithium ion battery, the welding plane of the soft tab and the hard tab of the multi-tab battery and the laminated battery is often bent to the thickness direction of the battery cell to reduce the three-dimensional size of the battery. The welding structure of the soft tab and the hard tab occupies a part of the head space of the battery cell. In order to utilize the space, the prior art battery protrudes the non-tab part in the head space to increase the volumetric energy density of the battery. However, the conventional laminated battery needs to occupy a part of space for the positive tab and the negative tab, and the non-tab part in the head space of the battery cell is small, so the effect of improving the energy density of the battery is limited.

[0052] Therefore, the embodiments of the utility model provide a kind of battery cell and battery, by making the first pole piece of battery cell form integrated structure, first pole piece can only be provided with one empty foil area connected with first adapter, so, after the bending of first pole piece, the corresponding position of multiple first bending parts with empty foil area can be coated with first active layer, increase the energy density of battery cell.

[0053] The embodiments of the first aspect of the utility model will be described below with reference to Figures 1 to 12 , an embodiment of a battery cell 200:

[0054] Embodiment 1

[0055] With reference to Figures 1 to 6 , the battery cell 200 can include a first pole piece 100, a plurality of second pole pieces 220, a separator 230, a first electrode adapter 240 and a second electrode adapter 250.

[0056] The first pole piece 100 can include a first current collector 110 and a first active layer. The first pole piece 100 can be used as a positive pole piece, the first current collector 110 can be a positive current collector, and the material of the positive current collector can be aluminum foil, aluminum-plated copper foil or aluminum-plated steel foil, etc. The first active layer is a positive active layer, and the commonly used materials can include lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), etc. Alternatively, the first pole piece 100 can also be used as a negative pole piece, the first current collector 110 is a negative current collector, and the material of the negative current collector can be aluminum foil or copper foil. The first active layer is a negative active layer, and the commonly used materials can include graphite, silicon-based materials or tin-based materials, etc.

[0057] The first current collector 110 can include a coated area 111 and an empty foil area 112. The coated area 111 is coated with the first active layer to perform electrochemical reaction, and the empty foil area 112 is not coated with the first active layer to facilitate connection with external electrical equipment through the adapter structure (such as the first electrode adapter 240). In other words, the empty foil area 112 of the present embodiment is the tab on the first pole piece 100.

[0058] The first pole piece 100 is bent along a first direction (such asFigure 1 The first end of the first current collector 110 in the first direction (as shown in the X direction) is provided with a plurality of first protrusions 113 and a plurality of first notches 114, which are staggered in the second direction (as shown in the Y direction). The empty foil area 112 is located on the first current collector 110 at the part where the first protrusions 113 are located. In this way, the first protrusions 113 provide more conductive paths, which can more efficiently conduct electrons. The first direction is perpendicular to the second direction. Figure 1

[0059] Referring to Figures 2 to 6 , the first tab 100 can include a plurality of first bending portions 211 stacked in a third direction (as shown in the Z direction), and the two ends of each first bending portion 211 in the second direction are connected to other first bending portions 211. In this way, the first tab 100 forms a structure similar to a plurality of connected "Z" characters in the third direction, so that each first notch 114 is arranged on a first bending portion 211, and the projections of the plurality of first notches 114 in the third direction overlap. The first direction, the second direction, and the third direction are perpendicular to each other. Figure 3

[0060] The second tab 220 is opposite in polarity to the first tab 100, and the first bending portion 211 and the second tab 220 are sequentially stacked in the third direction, i.e., a second tab 220 is located between two first bending portions 211 adjacent in the third direction. In this way, the formed battery cell 200 has a structure similar to a stacked cell, and the contact area between the second tab 220 and the first bending portion 211 is larger, which is beneficial to improving the rate performance of the battery while improving the energy density of the battery. Each second tab 220 includes a second current collector, and the second current collector is coated with a second active layer. The second current collector has a second empty foil area, and the second empty foil area forms a second sub-tab 221, which is located at the first end of the second tab 220 in the first direction, and has a gap between the second sub-tab 221 and the second current collector in the second direction. The projection of the second sub-tab 221 in the third direction at least partially overlaps the projection of the first notch 114 in the third direction. For example, the projection of the second sub-tab 221 can cover part of the projection of the first notch 114 in the third direction. Of course, the projection of the second sub-tab 221 can also cover all the projection of the first notch 114 in the third direction, so as to connect the second sub-tab 221 to the second electrode adapter 250.

[0061] Optionally, for the safety of the battery, in a conventional arrangement, the size of the negative electrode tab is slightly larger than that of the positive electrode tab. In this embodiment, the first bending portion 211 exceeds the size of the second tab 220, so the first tab 100 can be a negative electrode tab, and the second tab 220 can be a positive electrode tab.

[0062] ​​The diaphragm 230 is used to separate the first bending part 211 and the second pole piece 220, so that the first pole piece 100 and the second pole piece 220 are physically separated, thereby improving the safety of the battery.

[0063] The first electrode adapter 240 is electrically connected with the empty foil area 112, and the second electrode adapter 250 is electrically connected with the second sub-pole lug 221, and at least part of the structure of the second electrode adapter 250 is located in the first notch 114, wherein the structure of the second electrode adapter 250 located in the first notch 114 at least includes: the connection structure formed by the electrical connection between the second electrode adapter 250 and the plurality of second sub-pole lugs 221, so that the connection structure formed by the electrical connection between the second electrode adapter 250 and the plurality of second sub-pole lugs 221 is avoided to be damaged during the packaging of the battery, and the space utilization of the first notch 114 is improved, which is beneficial to improve the energy density of the battery.

[0064] The first pole piece 100 in the battery cell 200 can be regarded as a plurality of pole piece monomers of the same polarity being continuously connected, in the stacked core type battery cell of the prior art, the pole pieces of the same polarity are separately arranged, and a structure connected with the corresponding electrode adapter needs to be arranged on each pole piece, and the part of the pole piece connected with the electrode adapter does not have an active layer. Compared with this, the first pole piece 100 of the embodiment is of a whole structure, only needs to have an empty foil area 112 connected with the first electrode adapter, and the regions of the first pole piece 100 other than the empty foil area can be coated with a first active layer, the coating region of the active layer on the pole piece of the prior art is larger, and the energy density of the battery made of the pole piece of the embodiment is larger.

[0065] In addition, in the battery cell 200, the first pole piece 100 is repeatedly bent to form a plurality of first bending parts 211 stacked along the third direction, and the second pole piece 220 is arranged in the interval along the third direction between the two first bending parts 211, forming a structure similar to the stacked core type. In the partial roll core type battery cell of the prior art, a notch is arranged at the corresponding roll core type battery cell end position of the positive pole piece, the negative pole piece and the diaphragm to accommodate the pole lug, increase the coating region of the active layer, and thus improve the energy density of the battery. Compared with this, the second pole piece 220 of the battery cell of the application does not have a winding bending region, and the contact area between the second pole piece 220 and the first bending part 211 is larger than the contact area between the positive pole piece and the negative pole piece of the roll core type battery cell. While increasing the energy density of the battery cell, the transmission path between the electrons and the ions is shorter, and the battery cell has better rate performance.

[0066] In some embodiments, the width H of the first tab 100 along the first direction satisfies: 10 mm≤H≤200 mm; for example, H can be 10 mm, 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, or 200 mm. Of course, the width dimension H of the first tab 100 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation.

[0067] In this way, the width dimension of the first tab 100 along the first direction can be determined according to the width dimension of the battery along the first direction, which is convenient for application to different types of electrical equipment.

[0068] The length W of the first tab 100 along the second direction satisfies: 30 mm≤W≤2000 mm. For example, W can be 30 mm, 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, 1100 mm, 1200 mm, 1300 mm, 1400 mm, 1500 mm, 1600 mm, 1700 mm, 1800 mm, 1900 mm, or 2000 mm. Of course, the length dimension W of the first tab 100 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation.

[0069] In this way, the first tab 100 has sufficient length along the second direction, so that the first tab 100 can be bent multiple times and stacked along the third direction to match the thickness dimension of the battery when the battery cell 200 is processed.

[0070] In some embodiments, the length D1 of the empty foil area 112 along the first direction satisfies: 0.5 mm≤D1≤H; for example, the length D1 of the empty foil area 112 can be 0.5 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 10 mm, 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, or 200 mm. Of course, the length D1 of the empty foil area 112 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation. It should be noted that in the design, the value of the length D1 of the empty foil area 112 is limited to be less than the width H of the first tab 100. In this way, the empty foil area 112 is connected to the first electrode adapter 240.

[0071] The width W1 of the empty foil area 112 along the second direction satisfies: 2mm≤W1≤20mm. For example, the width W1 of the empty foil area 112 can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm or 20mm. Of course, the width W1 of the empty foil area 112 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation.

[0072] On the one hand, the width W1 of the empty foil area 112 is avoided to be too small (for example, less than 2mm), so that when the first electrode adapter 240 is connected with the empty foil area 112, the two sides of the first electrode adapter 240 along the second direction are directly in contact with the first current collector 110, which causes physical damage to the first tab 100. In addition, the direct connection between the first electrode adapter 240 and the first current collector 110 can cause a short circuit of the first tab 100. On the other hand, the width W2 of the empty foil area 112 is avoided to be too large (for example, more than 20mm), which occupies too large an area of the first current collector 110, so that the area of the coating area 111 is reduced, which reduces the energy density of the battery made of the first tab 100. In this way, the empty foil area 112 has a suitable width W1, which can not only ensure that the battery made of the first tab 100 has sufficient energy density, but also ensure that the first electrode adapter 240 will not be directly in contact with the first current collector 110, which improves the safety of the first tab 100.

[0073] The depth D2 of the first notch 114 along the first direction satisfies: 0.1mm≤D2≤10mm, for example, the depth of the first notch 114 along the first direction can be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm. Of course, the depth D2 of the first notch 114 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation. The first notch 114 has a suitable depth D2, so that when the first tab 100 of the present embodiment and the first tab 100 of opposite polarity (such as the second tab 220 in the following) are stacked to form the battery cell 200, the second sub-tab 221 on the second tab 220 is exposed to the first notch 114 and does not contact the first tab 100, which causes an internal short circuit of the battery, thereby improving the safety of the battery.

[0074] The width W2 of the first notch 114 along the second direction satisfies 2mm≤W2≤20mm. For example, the width W2 of the first notch 114 can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm. Of course, the width W2 of the first notch 114 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation. The first notch 114 has a suitable width size W2, so as to match the width size of the second sub-tab 221 on the second tab 220, so as to facilitate avoiding the second sub-tab 221 directly contacting the first tab 100, improving the safety of the battery, and on the other hand, avoiding the width size of the first notch 114 being too large (for example, more than 20mm), resulting in that the first active material layer on the first tab 100 loses more, affecting the energy density of the battery.

[0075] In some embodiments, the empty foil area 112 is located on the first current collector 110 at the part where the first protruding part 113 arranged along the second direction is located. For example, the empty foil area 112 can be located on the first tab 100 at the first protruding part 113 arranged along the second direction. Alternatively, the empty foil area 112 can be located on the last protruding part 113 arranged along the second direction. In other words, the empty foil area 112 can be located on one of the first and last protruding parts 113 arranged along the second direction of the first tab 100, so as to facilitate the assembly with the second tab 220 to form a core.

[0076] Along the second direction, the distance from the second sub-tab 221 to the two ends of the second tab 220 is different. Therefore, when the first tab 100 of the stacked core 200 is unfolded, the width size of any two adjacent first protruding parts 113 of the first tab 100, except the first protruding part 113 where the empty foil area 112 is located, is different. The width W3 of one of the first protruding parts 113 satisfies 0≤W3≤50mm. For example, W3 can be 0mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, or 50mm. The width W4 of the other of the two adjacent first protruding parts 113 satisfies 20≤W4≤100mm. For example, W4 can be 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, or 100mm. Of course, the width sizes W3 and W4 of the two adjacent first protruding parts 113 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not make any limitation.

[0077] This allows all the first notches 114 after the first electrode 100 is bent to be able to travel along a third direction ( Figure 3 Alignment (in the Z direction as shown) allows the second sub-tab 221 of the second electrode 220 to be fully exposed to the first notch 114, thereby improving the structural reliability of the cell 200.

[0078] refer to Figure 3 In some embodiments, there are two separators 230, which are respectively composited on both sides of the first electrode 100. In this way, the entire cell 200 contains only two separators 230, which helps to save raw materials. Furthermore, when the first electrode 100 is bent to form multiple first bends 211 stacked along a third direction, the separators 230 are bent simultaneously, which is convenient for processing and helps to improve production efficiency.

[0079] refer to Figure 5 According to some embodiments of the present invention, the diaphragm 230 has a second notch 231 that matches the first notch 114. The depth of the second notch 231 along the first direction is D3, where 0 ≤ D3 ≤ 9.5 mm. For example, the depth D3 of the second notch 231 can be 0 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, or 9.5 mm. Of course, the depth D3 of the second notch 231 can also be other values, and designers can choose according to their needs. This embodiment does not limit this.

[0080] This allows the depth of the second notch 231 to match that of the first notch 114, enabling the second sub-tab 221 to also be exposed to the second notch 231, thus improving the reliability of the structure. It should be noted that along the first direction, the edge of the second notch 231 extends beyond the edge of the first notch 114, thereby preventing the second sub-tab 221 from directly contacting the first notch 114 and causing a short circuit.

[0081] The width of the second notch 231 along the second direction is W5, where 1.5mm ≤ W5 ≤ 19mm. For example, the width W5 of the second notch 231 can be 1.5mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, or 19mm. Of course, the width W5 of the second notch 231 can also be other values, and designers can choose according to their needs; this embodiment does not impose any restrictions on this.

[0082] In this way, the width of the second notch 231 matches the first notch 114, so that the second sub-tab 221 can also be exposed to the second notch 231, improving the reliability of the structure. It should be noted that, in the second direction, the edge of the second notch 231 exceeds the edge of the first notch 114, so as to avoid the second sub-tab 221 directly contacting the first notch 114 to cause a short circuit.

[0083] With reference to the foregoing Figure 5 According to some embodiments of the present application, the edge of the diaphragm 230 along the circumferential direction covers the edge of the first tab 100 along the circumferential direction, and the edge of the diaphragm 230 not provided with the second notch 231 exceeds the edge of the first tab 100 not provided with the first notch 114 to form a first extension part 232, wherein the first extension part 232 can include the edge of the diaphragm 230 between the first end of the diaphragm 230 along the first direction and the first end of the first tab 100 not provided with the first notch 114, the edge between the second end of the diaphragm 230 along the first direction and the second end of the first tab 100, and the edge of the diaphragm 230 along the second direction exceeding the two ends of the first tab 100 along the second direction.

[0084] The width L1 of the first extension part 232 satisfies: 0.2mm≤L1≤2mm. For example, the width L1 of the first extension part 232 can be 0.2mm, 0.5mm, 1mm, 1.5mm or 2mm. Of course, the width L1 of the first extension part 232 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not limit this. In this way, the edge of the diaphragm 230 circumferentially covers the edge of the first bending part 211 to ensure the physical separation effect of the diaphragm 230 on the first tab 100 and the second tab 220.

[0085] The edge of the second notch 231 along the second direction exceeds the corresponding edge of the first notch 114 along the second direction to form a second extension part 233, and the width L2 of the second extension part 233 satisfies: 0.2mm≤L2≤3mm; for example, the width L2 of the second extension part 233 can be 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. Of course, the width L2 of the second extension part 233 can also be other values, which can be selected by the designer according to the needs, and the present embodiment does not limit this. In this way, the two side edges of the second notch 231 along the second direction cover the edges of the first notch 114, avoiding the second sub-tab 221 directly contacting the first notch 114 to cause a short circuit.

[0086] The edge of the second gap 231 along the first direction exceeds the corresponding edge of the first gap 114 along the first direction to form a third extension part 234, and the width L3 of the third extension part 234 satisfies: 0.5mm≤L3≤3mm. For example, the width L3 of the third extension part 234 can be 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. Of course, the width L3 of the third extension part 234 can also be other values, which can be selected according to the needs of the designer, and the present embodiment does not make any limitation. In this way, it is ensured that the edge of the second gap 231 along the first direction covers more than the edge of the first gap 114, avoiding the direct contact between the second sub-tab 221 and the first gap 114 to cause short circuit.

[0087] It should be noted that the heat generation at the second sub-tab 221 is large during use of the battery, and the width L3 of the third extension part 234 needs to be limited to be greater than the width L1 of the first extension part 232 and the width L2 of the second extension part 233, so as to avoid the melting of the third extension part 234 to cause the direct contact between the first pole piece 100 and the second pole piece 220, thereby improving the use safety of the battery.

[0088] Reference Figure 4 In some embodiments, the empty foil area 112 has a first welding mark 241 formed by welding with the first electrode adapter 240, and the battery cell 200 can further include: a welding mark protection glue, which at least covers the first welding mark 241, that is, the area of the welding mark protection glue can just cover the first welding mark 241, so as to protect the first welding mark 241 from being directly in contact with the second pole piece 220 to cause short circuit. Alternatively, the welding mark protection glue can also cover the empty foil area 112, thereby further fixing the first electrode adapter 240. Of course, the circumferential edge of the welding mark protection glue can also be in contact with the first active layer on the first current collector 110, so as to ensure the coverage effect on the empty foil area 112.

[0089] It can be understood that when the two separators 230 are compounded with the first pole piece 100, the first electrode adapter 240 has been connected to the first pole piece 100.

[0090] Reference Figure 2 and Figure 4In some embodiments, the battery cell 200 can further include tab adhesive 270, the surfaces of the first electrode adapter 240 and the second electrode adapter 250 are covered with the tab adhesive 270, and the tab adhesive 270 serves to fix the first electrode adapter 240 and the second electrode adapter 250 to the outer film shell of the battery when the battery cell 200 is packaged. In the first direction, the distance D4 between the tab adhesive 270 and the first bending part 211 satisfies: 0≤D4≤2mm. For example, D4 can be 0mm, 0.5mm, 1mm, 1.5mm, or 2mm. Of course, D4 can also be other values, and the designer can choose according to the needs, and the present embodiment does not make any limitation. In this way, the gap between the head of the battery cell 200 and the outer film shell of the battery is controlled, the relative volume of the battery cell 200 in the battery is improved, and the energy density of the battery is improved.

[0091] Reference Figure 6 In some embodiments, the plurality of second sub-tab 221 are stacked in the third direction to form a second tab, the second tab is welded with the second electrode adapter 250 and forms a second welding mark 251, at this time, the second electrode adapter 250 extends in the first direction to form a straight-out structure, which is convenient for production and processing.

[0092] Further, in the first direction, the distance D5 between the second welding mark 251 and the edge of the diaphragm 230 facing the first gap 114 in the first direction satisfies: 0≤D5≤8mm. For example, D5 can be 0mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 7mm, 7.5mm, or 8mm. Of course, D5 can also be other values, and the designer can choose according to the needs, and the present embodiment does not make any limitation. In this way, the part of the second electrode adapter 250 connected with the second tab and the second welding mark 251 are located in the first gap 114, avoiding the second welding mark 251 exceeding the first gap 114 and contacting the outer film shell of the battery to cause short circuit, improving the safety of the battery. At the same time, the space utilization rate of the first gap 114 is improved, the structure of the second electrode adapter 250 and the second tab connected with the second electrode adapter 250 is accommodated in the first gap 114, thereby improving the volume of the head of the battery cell 200 and improving the energy density of the battery.

[0093] Embodiment 2

[0094] Reference Figure 5 、 Figure 7 and Figure 8In the embodiment, the difference from the embodiment 1 is that, along the second direction, the gap on the side of the second sub-tab 221 away from the first electrode adapter 240 extends to the end of the second sub-tab 221 away from the first electrode adapter 240, forming a third notch, at this time, the second notch 231 on the diaphragm 230 and the first notch 114 on the first electrode tab 100 matched with the second notch 231 are all adaptively adjusted.

[0095] The depth of the second notch 231 along the first direction is D3, 0≤D3≤9.5mm, for example, the depth D3 of the second notch 231 can be 0mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm or 9.5mm. Of course, the depth D3 of the second notch 231 can also be other values, which can be selected by the designer according to the needs, and the embodiment does not make any limitation.

[0096] In this way, in the case of forming a third notch along the second direction on the second electrode tab 220, the depth of the second notch 231 remains unchanged, which is the same as in the embodiment 1, so as to match the first notch 114.

[0097] The width of the second notch 231 along the second direction is W6, 3mm≤W6≤38mm. For example, the width W6 of the second notch 231 can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm or 38mm. Of course, the width W6 of the second notch 231 can also be other values, which can be selected by the designer according to the needs, and the embodiment does not make any limitation.

[0098] In this way, the width of the second notch 231 is matched with the third notch on the second electrode tab 220, so that the second sub-tab 221 can be exposed to the second notch 231, improving the reliability of the structure.

[0099] The distance between two adjacent second notches 231 in the second direction is W7, and 20mm≤W7≤100mm. For example, W7 can be 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, or 100mm. Of course, the distance W7 between two adjacent second notches 231 can also be other values, which can be selected by the designer according to the needs, and the embodiment does not make any limitation. In this way, the second notch 231 of the diaphragm 230 matches the position of the third notch on the second pole piece 220, improving the structural reliability of the battery cell 200.

[0100] It can be understood that according to the width dimensions of the first extension part 232, the second extension part 233, and the third extension part 234 in Embodiment 1, the depth and width dimensions of the first notch 114 on the first pole piece 100 at this time can be inferred.

[0101] Embodiment 3

[0102] Reference Figures 9 to 10 The difference between this embodiment and Embodiment 1 is that the second electrode adapter 250 has a bent portion 250a and a body portion 250b, the bent portion 250a extends in the third direction, the body portion 250b extends in the first direction, and a plurality of second sub-pole tabs 221 are welded to the side of the bent portion 250a facing away from the first notch 114 to form second welds 251. In this way, the second electrode adapter 250 forms an L-shaped structure, the bent portion 250a can be accommodated in the first notch 114, further improving the utilization rate of the first notch 114, reducing the gap between the head of the battery cell 200 and the outer shell of the battery, and thus improving the energy density of the battery.

[0103] Further, in the first direction, the distance between the second weld 251 and the edge of the diaphragm 230 facing the first notch 114 is D6, and 0≤D6≤3mm. For example, D6 can be 0mm, 1mm, 3mm, 4mm, 5mm, or 6mm. Of course, the distance D6 between the second weld 251 and the edge of the diaphragm 230 facing the first notch 114 can also be other values, which can be selected by the designer according to the needs, and the embodiment does not make any limitation. In this way, it is ensured that the second weld 251 formed by welding the second sub-pole tab 221 and the bent portion 250a of the second electrode adapter 250 is located in the first notch 114, avoiding the second weld 251 exceeding the first notch 114 and contacting the outer shell of the battery to cause short circuit, improving the safety of the battery in use. At the same time, the space utilization rate of the first notch 114 is improved, the structure of the second electrode adapter 250 and the second sub-pole tab connected to the second electrode adapter 250 is accommodated in the first notch 114, thereby improving the volume of the head of the battery cell 200 and improving the energy density of the battery.

[0104] Embodiment 4

[0105] Reference Figures 11 to 12 In the embodiment, the difference from the embodiment 1 is that the diaphragm 230 is multiple, the diaphragm 230 is arranged on both sides of each second pole piece 220 respectively, and the diaphragm 230 is compounded with the second pole piece 220. In this way, the compound structure formed by the diaphragm 230 and the second pole piece 220 is located between the two first bending parts 211 along the third direction, thereby ensuring the physical separation effect of the diaphragm 230 on the first pole piece 100 and the second pole piece 220.

[0106] In this way, the battery cell 200 of the embodiment can also improve the coating area of the first active layer on the first pole piece 100, thereby improving the energy density of the battery.

[0107] In a second aspect, the embodiments of the application also provide a battery, which can include: an outer film shell and the above-mentioned battery cell 200, and the outer film shell covers the battery cell 200.

[0108] The battery of the utility model discloses, because used above-mentioned battery cell 200, increase the volume of the non-tab part of the head space of battery cell 200, improve the energy density of battery, prolong the endurance time of battery.

[0109] In the description of the utility model, it is to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0110] In the description of the utility model, "first feature", "second feature" can include one or more features.

[0111] In the description of the utility model, "multiple" means two or more.

[0112] In the description of the utility model, "above" or "below" of the first feature to the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them.

[0113] In the description of the utility model, "above", "above" and "above" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature.

[0114] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0115] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell (200), characterized in that, include: A first electrode (100) includes a first current collector (110) and a first active layer. The first current collector (110) includes a coating region (111) and an empty foil region (112). The coating region (111) is coated with the first active layer. The first electrode (100) has a plurality of first protrusions (113) and a plurality of first notches (114) arranged alternately along the second direction at one end along the first direction. The first direction is perpendicular to the second direction. The empty foil area (112) is disposed on the first current collector (110) in the part where the first protrusions (113) are located. The first electrode (100) includes a plurality of first bends (211) stacked along a third direction. The two ends of the plurality of first bends (211) along the second direction are respectively connected to other first bends (211). Each first notch (114) is disposed in one of the first bends (211). The projections of the plurality of first notches (114) in the third direction overlap. Multiple second pole pieces (220), the first bent portion (211) and the second pole pieces (220) are stacked sequentially along the third direction, each second pole piece (220) has a second sub-pole tab (221) at a first end along the first direction, and the projection of the second sub-pole tab (221) in the third direction at least partially coincides with the projection of the first notch (114) in the third direction; A diaphragm (230) separates the first bent portion (211) and the second electrode (220). A first electrode adapter (240) and a second electrode adapter (250), wherein the first electrode adapter (240) is electrically connected to the empty foil area (112), and the second electrode adapter (250) is electrically connected to the second sub-electrode tab (221), and at least a portion of the structure of the second electrode adapter (250) is located within the first notch (114).

2. The battery cell (200) according to claim 1, characterized in that, The width H of the first electrode (100) along the first direction satisfies: 10mm ≤ H ≤ 200mm; and / or, The length W of the first electrode (100) along the second direction satisfies: 30mm≤W≤2000mm.

3. The battery cell (200) according to claim 2, characterized in that, The length D1 of the empty foil area (112) along the first direction satisfies: 0.5mm ≤ D1 ≤ H; and / or, The width W1 of the empty foil area (112) along the second direction satisfies: 2mm≤W1≤20mm.

4. The battery cell (200) according to claim 1, characterized in that, The depth D2 of the first notch (114) along the first direction satisfies: 0.1mm ≤ D2 ≤ 10mm; and / or, The width W2 of the first notch (114) along the second direction satisfies: 2mm≤W2≤20mm.

5. The battery cell (200) according to claim 4, characterized in that, The empty foil area (112) is located on the first current collector (110) of the portion where the first protrusion (113) is arranged along the second direction. Among the other first protrusions (113) besides the empty foil area (112), the width W3 of any two adjacent ones satisfies: 0≤W3≤50mm, and the width W4 of the other one satisfies: 20≤W4≤100mm.

6. The battery cell (200) according to claim 1, characterized in that, There are two diaphragms (230), and the two diaphragms (230) are respectively bonded to both sides of the first electrode (100).

7. The battery cell (200) according to claim 6, characterized in that, The diaphragm (230) has a second notch (231) that matches the first notch (114), the second notch (231) having a depth D3 along the first direction, where 0 ≤ D3 ≤ 9.5 mm. The width of the second notch (231) along the second direction is W5, 1.5mm≤W5≤19mm.

8. The battery cell (200) according to claim 6, characterized in that, The diaphragm (230) has a second notch (231) that matches the first notch (114), the second notch (231) having a depth D3 along the first direction, where 0 ≤ D3 ≤ 9.5 mm. The width of the second notch (231) along the second direction is W6, 3mm ≤ W6 ≤ 38mm, and / or, The distance between two adjacent second gaps (231) along the second direction is W7, 20mm≤W7≤100mm.

9. The battery cell (200) according to any one of claims 7 or 8, characterized in that, The edge of the diaphragm (230) along the circumferential direction covers beyond the edge of the first electrode (100) along the circumferential direction. The edge of the diaphragm (230) without the second notch (231) extends beyond the edge of the first bent portion (211) without the first notch (114) to form a first extension portion (232), the width L1 of which satisfies: 0.2mm ≤ L1 ≤ 2mm; and / or, The edge of the second notch (231) along the second direction extends beyond the corresponding edge of the first notch (114) along the second direction to form a second extension (233), the width L2 of the second extension (233) satisfying: 0.2mm ≤ L2 ≤ 3mm; and / or, The edge of the second notch (231) along the first direction extends beyond the corresponding edge of the first notch (114) along the first direction to form a third extension (234), the width L3 of the third extension (234) satisfying: 0.5mm≤L3≤3mm.

10. The battery cell (200) according to claim 1, characterized in that, The empty foil area (112) has a first solder mark (241) formed by welding with the first electrode adapter (240). The battery cell (200) further includes: solder sealant, which at least covers the first solder seal (241).

11. The battery cell (200) according to claim 1, characterized in that, It also includes tab adhesive (270), and the surfaces of both the first electrode adapter (240) and the second electrode adapter (250) are covered with the tab adhesive (270). Along the first direction, the distance D4 between the tab adhesive (270) and the first bent portion (211) satisfies: 0≤D4≤2mm.

12. The battery cell (200) according to claim 1, characterized in that, Multiple second sub-tabs (221) are stacked along the third direction to form a second tab, and the second tabs are welded to the second electrode adapter (250) to form a second solder mark (251). The second electrode adapter (250) extends along the first direction.

13. The battery cell (200) according to claim 12, characterized in that, Along the first direction, the distance D5 between the second solder mark (251) and the edge of the diaphragm (230) facing the first notch (114) in the first direction satisfies: 0≤D5≤8mm.

14. The battery cell (200) according to claim 1, characterized in that, The second electrode adapter (250) has a bent portion (250a) and a body portion (250b) formed by bending, the bent portion (250a) extending along the third direction, and the body portion (250b) extending along the first direction. Multiple second sub-taperes (221) are welded to the side of the bent portion (250a) facing outward from the first notch (114) to form a second weld mark (251).

15. The battery cell (200) according to claim 14, characterized in that, Along the first direction, the distance between the second solder mark (251) and the edge of the diaphragm (230) facing the first notch (114) is D6, 0≤D6≤3mm.

16. The battery cell (200) according to claim 1, characterized in that, There are multiple diaphragms (230), and the diaphragms (230) are respectively disposed on both sides of each second electrode (220), and the diaphragms (230) are composite with the second electrode (220).

17. A battery, characterized in that, include: Outer membrane shell; The battery cell (200) according to any one of claims 1-16, wherein the outer membrane shell covers the battery cell (200).

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