Injection molded frame for busbar grid, busbar grid, pole plate and composite energy storage battery

Abstract

The present application relates to a kind of injection frame for busbar grid, busbar grid, polar plate and composite energy storage battery, belong to lead-acid energy storage battery technical field, solve the problem that lead wire in the busbar grid in the prior art cannot efficiently act current on active material area.The injection frame for busbar grid includes the first border near cast welding area, the second border opposite and parallel with the first border, the third border connecting one end of first border and one end of second border, and the fourth border connecting the other end of first border and the other end of second border, the third border and the fourth border are parallel;The first border and the second border are respectively provided with equal number of lead wire holes;The lead wire hole on the first border is single-layer arrangement;The lead wire hole on the second border is at least two layers arrangement, and the lead wire hole of adjacent two layers is staggered arrangement.The present application can efficiently act current on active material area.

Description

Technical Field

[0001] This invention relates to the field of lead-acid energy storage battery technology, and in particular to an injection-molded frame for a busbar grid, a busbar grid, an electrode plate, and a composite energy storage battery. Background Technology

[0002] Energy storage batteries mainly refer to batteries used in solar power generation equipment, wind power generation equipment, and renewable energy storage. They have the advantages of high energy density, good safety performance, long cycle life, fast charging and discharging capability, low self-discharge rate, and green environmental protection.

[0003] The plates of a storage battery consist of a busbar grid and active material coated within the grid frame. Composite lead wires within the active material coating area act as current collectors for the plates, conducting current after activating the battery's performance. However, the lead wires in existing busbar grids cannot efficiently transfer current to the active material area. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide an injection-molded frame for a busbar grid, a busbar grid, an electrode plate, and a composite energy storage battery to solve the problem that lead wires in existing busbar grids cannot efficiently apply current to the active material region.

[0005] On one hand, the present invention provides an injection molded frame for a busbar grid, the injection molded frame for a busbar grid includes a first frame near the casting and welding area, a second frame opposite to and parallel to the first frame, a third frame connecting one end of the first frame and one end of the second frame, and a fourth frame connecting the other end of the first frame and the other end of the second frame, the third frame and the fourth frame being parallel.

[0006] The first frame and the second frame are provided with an equal number of wire holes; the wire holes on the first frame are arranged in a single layer; the wire holes on the second frame are arranged in at least two layers, and the wire holes in adjacent layers are staggered.

[0007] Preferably, on the second frame, the vertical distance between the centers of two adjacent wire holes is less than the diameter of the wire hole.

[0008] Preferably, the thickness of the first frame gradually decreases along the outward extension direction, forming a trapezoidal cross-section.

[0009] Preferably, the injection-molded frame for the busbar grid further includes a plurality of horizontal ribs disposed within a square frame enclosed by the four side borders, the horizontal ribs being parallel to the first side border.

[0010] Preferably, the cross-sections of the second frame, the third frame, the fourth frame, and the horizontal rib are all rhomboid.

[0011] Secondly, the present invention also provides a busbar grid, the busbar grid including lead wire and the injection-molded frame for the busbar grid, wherein the lead wire intersects the transverse rib perpendicularly.

[0012] Preferably, the multi-layered lead wires between the second frame and the horizontal ribs near the first frame are arranged in parallel, and the lead wires between the horizontal ribs near the first frame and the first frame are gradually arranged into a single layer of lead wires from the horizontal ribs near the first frame toward the first frame.

[0013] Preferably, the side of the electrode plate surface near the intersection of the lead wire and the transverse rib is not completely covered by injection molding compound.

[0014] Thirdly, the present invention also provides an electrode plate, the electrode plate comprising the above-mentioned busbar grid and active material.

[0015] Fourthly, the present invention also provides a composite energy storage battery, the composite energy storage battery comprising a positive electrode busbar, a negative electrode busbar, multiple battery cells and multiple of the above-mentioned electrode plates;

[0016] The electrode plates and battery cells are stacked at intervals;

[0017] The battery cell has two sides with opposite polarities;

[0018] Adjacent battery cells with the same electrode polarity are arranged facing each other and connected by electrode plates;

[0019] The electrode plates include a positive electrode plate and a negative electrode plate;

[0020] The end of the positive electrode plate is connected to the positive electrode busbar via a connector;

[0021] The end of the negative plate is connected to the negative busbar via a connector.

[0022] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0023] 1. In the injection-molded frame for the busbar grid of the present invention, the lead wire holes on the first frame are arranged in a single layer, and the lead wire holes on the second frame are arranged in at least two layers. This allows the lead wires to be distributed in at least two layers within the frame, forming a three-dimensional grid. The multi-layered distribution of lead wires is beneficial for the current transmission during battery use, and can ensure that the current density of each part of the plate is evenly distributed during charging and discharging, efficiently applying the current to the active material area, and achieving an active material utilization rate of 37-39%.

[0024] 2. The lead wire holes on the first frame of the present invention are arranged in a single layer, that is, the lead wires on the first frame are arranged in a single layer, which is beneficial to the subsequent casting and welding connection with the busbar. Compared with the multi-layer arrangement of lead wire holes on the first frame, the single-layer arrangement of lead wire holes on the first frame of the present invention can reduce the rework rate of the casting and welding points.

[0025] 3. The injection-molded frame for the busbar grid of the present invention can make the lead wires in a single grid distributed in multiple layers, which is equivalent to the multi-layer superposition of traditional single-layer lead wire grids. However, the total number of lead wires in the present invention does not change, so the weight of the grid changes very little.

[0026] 4. The injection molding frame for the busbar grid of the present invention allows the lead wires in a single grid to be distributed in multiple layers. During the injection molding of the grid, the composite lead wires are pre-set in the mold. There is a 10-second pause when the mold is closed during injection molding. The injection direction of the injection molding compound is as follows: Figure 5 The direction indicated by the curve is such that the side of the double-layer composite lead wire in the grid of this invention, opposite to the injection molding direction, can be coated in the opposite direction by injection molding pressure. This results in less injection molding adhesive covering the side of the lead wire near the electrode surface, meaning that the side of the lead wire near the electrode surface where it intersects with the transverse rib is not completely covered by injection molding adhesive, increasing the conductive area of ​​the lead wire. Furthermore, a smaller overcoating amount is needed to cover the entire grid when applying the active material. The overcoating amount refers to the active material thickness from the side of the transverse rib near the electrode surface to the electrode surface × 2 (i.e., the electrode thickness minus the transverse rib thickness). The active material overcoating amount of the grid of this invention is 0.6 mm to 1 mm, covering all internal ribs of the injection-molded grid at this thickness.

[0027] 5. In the injection-molded frame for the busbar grid of the present invention, the cross-section of the first frame is trapezoidal, which can gradually organize the multi-layer lead wires into a single layer, and can effectively protect the composite lead wires without active material coating from corrosion during the cycle life. Moreover, the four frames form a square frame for the electrode plate, which can suppress the expansion and shedding of active material during the cycle life.

[0028] 6. The cross-sections of the second, third, and fourth borders and the horizontal ribs are all rhomboid, which can provide the greatest stable support with the least amount of injection molding material; moreover, the rhomboid structure occupies less volume and has less impact on the space occupied by the active material; in addition, the rhomboid structure makes demolding during the injection molding process easier.

[0029] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0030] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0031] Figure 1aThis is a schematic diagram of the structure of a busbar grid including the injection-molded frame and lead wire of the present invention.

[0032] Figure 1b This is a three-dimensional structural diagram of a busbar grid including the injection-molded frame and lead wire of the present invention.

[0033] Figure 2 This is a side view of one side of the second frame of the injection-molded frame for the busbar grid of the present invention.

[0034] Figure 3 This is a side view of one side of the first frame of the injection-molded frame for the busbar grid of the present invention.

[0035] Figure 4 This is a side view of the third frame side of the injection-molded frame for the busbar grid of the present invention.

[0036] Figure 5 This is a schematic diagram of the injection direction of the injection molding compound.

[0037] Figure 6 This is a three-dimensional view of the busbar of the present invention.

[0038] Figure 7 This is the main view of the busbar of the present invention.

[0039] Figure 8 This is a top view of the busbar of the present invention.

[0040] Figure 9 This is a side view of the busbar of the present invention.

[0041] Figure 10 This is a top view of the screw connection portion of the present invention.

[0042] Figure 11 This is an isometric side view of the composite energy storage battery of the present invention.

[0043] Figure 12 This is a side view of the composite energy storage battery of the present invention.

[0044] Figure 13 for Figure 8 Sectional view of plane AA.

[0045] Figure 14 This is a diagram showing the variation of the height H of the center line of the longitudinal axis of the conductive rib with the position of the conductive rib relative to the axis of symmetry of the busbar in one embodiment of the present invention.

[0046] Figure 15a The graph shows the data from the cyclic test in Comparative Example 2.

[0047] Figure 15b The graph shows the data from the cyclic test in Comparative Example 7.

[0048] Figure label:

[0049] 1-First frame; 2-Second frame; 3-Third frame; 4-Fourth frame; 5-Lead wire hole; 6-Horizontal rib; 7-Lead wire; 8-Bus connector; 8a-First busbar connector; 8b-Second busbar connector; 9-Electric plate; 10-Positive busbar; 11-Negative busbar; 12-Battery unit;

[0050] 01-Conductive terminal block; 011-Column body; 012-Core body; 013-Screw hole; 02-Screw connection part; 021-Arc-shaped connection part; 03-Buffer grid; 031-Buffer area; 032-Conductive rib. Detailed Implementation

[0051] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0052] On one hand, the present invention provides an injection-molded frame for a busbar grid, such as Figure 1a , Figure 1b , Figures 2-3 As shown, the injection-molded frame for the busbar grid includes a first frame 1 near the casting area, a second frame 2 opposite to and parallel to the first frame 1, a third frame 3 connecting one end of the first frame 1 and one end of the second frame 2, and a fourth frame 4 connecting the other end of the first frame 1 and the other end of the second frame 2, wherein the third frame 3 and the fourth frame 4 are parallel.

[0053] The first frame 1 and the second frame 2 are provided with an equal number of wire holes 5; the wire holes 5 on the first frame 1 are arranged in a single layer; the wire holes 5 on the second frame 2 are arranged in at least two layers, and the wire holes between adjacent layers are staggered.

[0054] Compared with the prior art, in the injection-molded frame for the busbar grid of the present invention, the lead wire holes on the first frame are arranged in a single layer, and the lead wire holes on the second frame are arranged in at least two layers. This allows the lead wires to be distributed in at least two layers within the frame, forming a three-dimensional grid. The multi-layered distribution of lead wires is beneficial for the current transmission during battery use, enabling the current density of each part of the plate to be evenly distributed during charging and discharging, and efficiently applying the current to the active material area, achieving an active material utilization rate of 37-39%. At the same time, the lead wire holes on the first frame are arranged in a single layer, which is beneficial for subsequent casting and welding connection with the busbar. The injection-molded frame for the busbar grid of the present invention allows the lead wires in a single grid to be distributed in multiple layers, which is equivalent to the multi-layer stacking of traditional single-layer lead wire grids, but with very little change in weight.

[0055] For example, the lead wire holes 5 of the first frame 1 and the lead wire holes 5 of the second frame 2 are in one-to-one correspondence. The term "one-to-one correspondence" means that the projections of the lead wire holes of the first frame 1 and the lead wire holes of the second frame 2 on the electrode plate plane are in one-to-one correspondence.

[0056] For example, the lead wire hole 5 is used to pass through pure lead wire, alloy lead wire, composite lead wire, etc.

[0057] For example, on the second frame 2, the vertical distance between the centers of two adjacent layers of lead wire holes is less than the diameter of the lead wire hole 5. That is, the two adjacent layers of lead wire holes overlap in the direction perpendicular to the electrode plane. When the horizontal ribs are injection molded, the injection molding compound can achieve reverse coating of the lead wires, so that the side of the lead wires near the electrode surface is covered with less injection molding compound. That is, the side of the lead wires near the electrode surface where they intersect is not completely covered by injection molding compound, increasing the conductive area of ​​the grid.

[0058] For example, the height h of the overlapping portion of two adjacent wire mesh layers in the direction perpendicular to the second frame is greater than or equal to 1 / 3 of the wire mesh diameter. In this preferred embodiment, the utilization of active material between adjacent wire mesh layers can be promoted, thereby improving the overall utilization rate of active material.

[0059] For example, the height h of the overlapping portion of two adjacent wire holes in the direction perpendicular to the second frame is greater than or equal to 1 / 3 of the wire hole diameter and less than or equal to 2 / 3 of the wire hole diameter.

[0060] For example, the distance between the wire hole near the edge of the second frame and the edge of the second frame is 0.5 mm.

[0061] For example, the thickness of the first frame 1 gradually decreases along the outward extension direction, forming a trapezoidal cross-section. This effectively protects the uncoated composite lead wire from corrosion during its cycle life. Furthermore, the four frames form the square frame of the electrode plate, which can suppress the expansion and shedding of the active material during the cycle life.

[0062] In this invention, the casting-welding area refers to the area where the grid and busbar are cast-welded together. The first frame 1 of the trapezoidal cross-section facilitates the gradual arrangement of multi-layer lead wires into a single layer, providing convenience for subsequent casting-welding, reducing work difficulty, and improving product qualification rate. Moreover, the distance between the first frame 1 of the trapezoidal cross-section and the outer frame lug is equal to the thickness of the cast-welded busbar. The composite lead wire here functions as the lug of a traditional electrode plate, but its electrical performance is superior to that of a traditional lug.

[0063] Taking the second frame with two layers of wire holes as an example, the wire holes of the first frame 1 extend from the side close to the second frame to the side far away from the second frame, gradually arranging the two layers of wire holes into a single layer of wire holes.

[0064] For example, the height of the trapezoidal section is based on the lead wire reserved for the thickness of the cast-welded busbar. The height of the trapezoidal section ensures that the composite lead wire reserved during the cast-welding of the busbar is embedded in the lead molten metal of the busbar, and no excess composite lead wire is exposed to the acidic environment.

[0065] For example, the injection-molded frame for the busbar grid also includes a plurality of horizontal ribs 6 disposed within a square frame enclosed by the four side borders, the horizontal ribs 6 being parallel to the first side border 1. The horizontal ribs 6 are perpendicular to the composite lead wire, serving to stabilize the lead wire and also providing lateral strength support for the overall electrode active material.

[0066] For example, the horizontal ribs 6 are evenly distributed in the frame.

[0067] For example, the cross-sections of the second frame 2, the third frame 3, the fourth frame 4, and the horizontal rib 6 are all rhomboid. The rhomboid design of the frame and the horizontal rib 6 takes into account both demolding during the injection molding process and the reduction of the force exerted on the injection frame by the mechanical deformation of the grid and the expansion of the active material during the cycle life. Regarding demolding, the rhomboid angle represents the maximum demolding angle of the injection molded part; on the other hand, the expansion of the active material during the cycle life is unavoidable, and all the forces generated by the expansion act first on the injection frame. The rhomboid structure reduces the degree of deformation of the injection frame caused by the expansion force, thereby increasing the cycle life.

[0068] For example, a pair of opposite corners in the rhomboid structure of the second border 2, the third border 3, the fourth border 4 and the horizontal rib 6 face the two sides of the electrode plate respectively.

[0069] The thickness of the frame can be determined based on the thickness of the electrode plate. For example, the thickness of the first frame 1, the second frame 2, the third frame 3 and the fourth frame 4 is 0.4-0.7 mm less than the thickness of the electrode plate.

[0070] For example, the thickness of the first border 1, the second border 2, the third border 3 and the fourth border 4 are equal and are 0.2-0.3 mm thicker than the thickness of the horizontal rib 6.

[0071] Secondly, the present invention also provides a busbar grid, the busbar grid including lead wire 7 and the above-mentioned injection-molded frame for the busbar grid, wherein the lead wire intersects the transverse rib perpendicularly.

[0072] The process of converting multi-layer lead wire into single-layer lead wire can include the following three implementation methods:

[0073] In the first embodiment, the multi-layered lead wires of the second frame extend toward the first frame and are gradually arranged into a single layer of lead wires.

[0074] In the second embodiment, the multi-layered lead wires between the second frame and any one of the horizontal ribs are arranged in parallel, and the lead wires between the horizontal rib and the first frame are gradually arranged into a single layer of lead wires from the horizontal rib toward the first frame.

[0075] In the third embodiment, the multi-layered lead wires between the second frame and the horizontal ribs near the first frame are arranged in parallel, and the lead wires between the horizontal ribs near the first frame and the first frame are gradually arranged into a single layer of lead wires towards the first frame. In this embodiment, only the lead wires between the horizontal ribs near the first frame and the first frame gradually move away from the electrode surface, while the lead wires in other areas are parallel to the electrode surface. This is beneficial for the utilization of active materials on the electrode surface, and the reduction in active material utilization due to the lead wires between the horizontal ribs near the first frame moving away from the electrode surface is negligible compared to the overall active material utilization rate. Therefore, compared with the first two embodiments, the third embodiment can maximize the utilization of active materials while facilitating subsequent casting and welding with the busbar, making it an optimal embodiment.

[0076] Specifically, the lead wire 7 passes through the lead wire holes corresponding to the first frame 1 and the second frame 2 respectively, and the lead wire is perpendicularly connected to the horizontal rib 6 to form a grid in the square frame.

[0077] For example, the side of the lead wire near the electrode plate surface where it intersects with the transverse rib is not completely covered by injection molding, thereby increasing the conductive area of ​​the lead wire.

[0078] For example, the height of the portion of the lead wire not covered by the injection molding compound is greater than 0 and less than or equal to 1 / 3 of the lead wire diameter. This ensures that the lead wire is fixed by the horizontal ribs while increasing the conductive area of ​​the lead wire. The height of the portion of the lead wire not covered by the injection molding compound refers to the height perpendicular to the surface of the electrode plate.

[0079] It should be noted that the end of the lead wire 7 near the casting and welding area extends beyond the outer edge of the first frame 1, and the extended end of the lead wire is connected to the busbar through a bus connector.

[0080] For example, the lead wire can be pure lead wire, alloy lead wire, composite lead wire, etc., preferably composite lead wire.

[0081] Thirdly, the present invention also provides an electrode plate, the electrode plate comprising the above-mentioned busbar grid and active material.

[0082] Fourthly, the present invention also provides a composite energy storage battery, the composite energy storage battery comprising a positive electrode busbar 10, a negative electrode busbar 11, a plurality of battery cells 12 and a plurality of the aforementioned electrode plates 9;

[0083] The electrode plate 9 and the battery unit 12 are stacked at intervals;

[0084] The battery cell 12 has two sides with opposite polarities;

[0085] Adjacent battery cells 12 with the same electrode polarity are arranged facing each other and connected by electrode plates 9;

[0086] The electrode plate 9 includes a positive electrode plate and a negative electrode plate;

[0087] The end of the positive electrode plate is connected to the positive electrode busbar 10 via the busbar connector 8;

[0088] The end of the negative plate is connected to the negative busbar 11 via the busbar connector 8.

[0089] In this invention, the positive bus 10 and the negative bus 11 are collectively referred to as busbars.

[0090] In existing energy storage battery busbars, on the one hand, the difference between the input and output currents of the busbar and the maximum conductivity of the overall grid are not considered, resulting in significant energy loss; on the other hand, the battery busbar adopts a split molding technology, and each component needs to be formed with lead alloy. In order to increase the connection strength, the existing technology uses a large amount of lead alloy, which has the disadvantages of adjacent connection structure interlocking and expansion in all directions, and does not meet the design requirements of improving battery safety and miniaturization.

[0091] Based on this, such as Figures 6-8 The busbar of the present invention includes a conductive terminal 01, a screw connection 02, and a busbar grid 03.

[0092] The current collection grid includes multiple conductive ribs 032; each conductive rib 032 is connected to multiple current collection connectors 8, and the current is collected in the conductive rib 032 through the current collection connectors 8; the multiple current collection connectors 8 are distributed along the height direction of the conductive ribs, and each current collection connector 8 can independently collect the current of the electrode plate 9.

[0093] Preferably, multiple conductive ribs 032 are arranged in parallel, and each conductive rib 032 can collect current in each area individually.

[0094] Specifically, multiple busbar connectors 8 converge on one side of the conductive rib, connect to the external circuit through one end of the conductive rib, and form a free end at the other end of the conductive rib.

[0095] Preferably, the merging grid 03 further includes a merging area 031;

[0096] One end of the busbar 031 is fixed with a conductive rib 032, and the other end is connected to an external circuit.

[0097] Specifically, such as Figure 12As shown, the conductive rib 032 is connected to multiple bus connectors 8 from its free end to the end connected to the bus junction area 031, which are named sequentially as the first bus connector 8a, the second bus connector 8b, ..., the Nth bus connector.

[0098] The current collector 8 collects current and converges it on the conductive rib 032, causing the current flowing from the free end of the conductive rib 032 to the end connected to the current collection area to gradually increase.

[0099] Preferably, the cross-sectional area of ​​the conductive rib 032 gradually increases from the free end to the end connected to the current-collecting area 031, thereby reducing the loss caused by the increase in current.

[0100] Specifically, the cross-sectional area S at each point of the conductive rib 032 satisfies: S≥U×n / (ρ×L0×I0), where U is the electromotive force of the battery cell where the conductive rib 032 is located, L0 is the distance between the first busbar 8a and the second busbar 8b, I0 is the current flowing through the first busbar 8a under the action of U, ρ is the resistivity of the conductive rib 032, and n is the number of busbars connected to the conductive rib 032.

[0101] It should be noted that the number n of the busbar connectors 8 is determined by the processing technology and the electrical loss of the busbar connectors themselves. A larger number of busbar connectors helps to reduce their own losses, but it brings greater processing difficulties (most busbar connectors are made of lead wires extending from the power electrode plate, so their own diameter limits their number and cannot be increased indefinitely). Therefore, n satisfies the following: the interval between adjacent busbar connectors is between 4.8mm and 6.5mm.

[0102] Preferably, the busbar connectors 8 are evenly spaced, and the busbar connectors 8 are evenly distributed on the electrode plates 9, with the interval between adjacent busbar connectors equal to the electrode plate height H2 / (n+1).

[0103] For example, such as Figure 12 As shown, each conductive rib 032 has 14 busbars. On one hand, one end of the busbar 8 is connected to the electrode plate, dividing the electrode plate into 15 regions with uniform height. On the other hand, the other end of the busbar 8 is connected to the conductive rib 032, so that the conductive rib 032 continuously converges from the free end to the end connected to the busbar area 031, collecting the output current from all parts of the electrode plate and transmitting it to the busbar area 031.

[0104] Preferably, the cross-sectional area S at each point of the conductive rib 032 continuously varies to satisfy: S=S0+(Smax-S0)×(L-L0) / (Lmax-L0);

[0105] Where L is the distance from the free end of each part of the conductive rib 032, L0 is the distance between the first busbar 8a and the second busbar 8b, Lmax is the length of the conductive rib 032, S0 is the cross-sectional area of ​​the free end, which can be set according to the design specifications and actual processing conditions; Smax is the cross-sectional area of ​​the end where the conductive rib 032 connects to the busbar area 031, and Smax satisfies: Smax=S0×n.

[0106] It is understandable that (Smax-S0) / (Lmax-L0) is the slope of the change in bus thickness / cross-sectional area.

[0107] It should be noted that an excessively large S0 results in an increase in the width and cross-sectional area of ​​the conductive rib 032, while an excessively small S0 results in greater losses in the conductive rib. S0 should satisfy the following condition: S0 is within 0.5mm. 2 ~10mm 2 between.

[0108] Compared with existing technologies, by Figure 9 As can be seen, this invention gradually increases the cross-sectional area of ​​the conductive ribs from the free end to the end connected to the busbar as the current increases throughout the conductive ribs, forming a slope for the thickness / cross-sectional area change of the busbar. This fully considers the proportional relationship between current density and the cross-sectional area of ​​the conductive busbar, ensuring that the conductive current per square millimeter is the same. This not only controls the relationship between internal resistance and current distribution but also fully utilizes the conductive alloy and active material. Compared with horizontal lead-acid grid batteries, it reduces the increase in losses caused by the increase in incoming current, and at the same time, it reduces the amount of raw materials required compared to conductive ribs of uniform thickness, thus lowering costs.

[0109] Preferably, the height L of each conductive rib connected to the busbar 031 gradually increases from the center of the busbar 031 to both sides.

[0110] It should be noted that the current entering the top of each conductive rib connected in the busbar area is at different distances from the busbar area and the screw connection, and the paths within the busbar area are different, resulting in different actual losses. This can easily lead to uneven output current of each conductive rib, causing different output performance of each conductive rib, busbar connector and the connected battery cell. Over time, this will cause different losses and performance differences of battery cells in different areas, affecting service life and stability.

[0111] Specifically, such as Figure 14 As shown, with the straight line containing the bottom edge of conductive rib 032 as the x-axis, the intersection of the center line of the vertical axis of busbar 1 and the x-axis as the origin, and the height H of conductive rib 032 on its vertical axis center line as the y-axis, a functional relationship between H and X is constructed: H = aX 2 +bX+c, where a=0.0025~0.005, b=-0.5~-1, c=170~180.

[0112] It should be noted that, as Figure 7 As shown, the midpoint P of the line connecting the left and right vertices of the upper part of the conductive rib 032 is defined as the highest point of the conductive rib, and the distance from the highest point of the conductive rib 032 to the bottom edge of the conductive rib 032 is the height H of the center line of the longitudinal axis of the conductive rib; at the same time, the midpoint of the top of the current collection area 031 is defined as O, and the height difference between the top of the current collection area 031 and the highest point of each conductive rib is H1. The line segment PO shows the equivalent current collection path of the conductive rib 032.

[0113] It is understandable that each conductive rib has a corresponding PO line segment representing its equivalent current-carrying path. Each equivalent current-carrying path converges from the center point P at the top of each conductive rib to point O. For clarity and simplicity, Figure 7 The PO line segment only schematically illustrates an equivalent confluence path.

[0114] The inventors discovered that setting the height of the conductive ribs according to the above-mentioned functional relationship between H and X results in lower power loss and output efficiency compared to setting all conductive ribs at the same height, especially when H1 < 15mm.

[0115] Understandably, H1 reflects the height of the busbar 031. A smaller H1 helps to reduce the volume of the busbar 031 and even the busbar itself, thus reducing raw material consumption. However, this also brings the defects of large current loss and uneven current distribution among the conductive ribs.

[0116] Compared with the prior art, the present invention adjusts the height of the conductive ribs according to the position of each conductive rib relative to the current collection area, optimizes the current transmission path of the conductive ribs in the current collection area, reduces losses and makes the output of battery cells in different areas more uniform, which helps to improve the battery's service life and stability.

[0117] The screw connection 02 is a trapezoidal block. The short side of the trapezoidal block is connected to the bottom of the conductive terminal 01, and the long side is connected to the current collection area 031 of the current collection grid 03.

[0118] During implementation, current is collected and transmitted from the busbar 03 to the conductive terminal 01. The long side is connected to the top of the busbar 03, and the bottom side is connected to the conductive terminal 01. The screw connection 02 can bridge the busbar 03 and the conductive terminal 01. The trapezoidal block design can save the amount of screw connection material without increasing the current transmission voltage drop.

[0119] Compared with the prior art, the present invention uses a busbar to combine the current in each region and solves the problem of uneven distribution of output and input current caused by the setting of a single tab (bus connector) in the prior art. Compared with the single tab of the plate of the traditional energy storage battery, the composite energy storage battery of the present invention has dozens or more tabs, and each tab (bus connector) is individually connected to the busbar. This design results in uniform current distribution, high utilization of active material, and strong high current charging and discharging capability.

[0120] It should be noted that during casting and welding, exposed weld lines will be formed in the welding area. These weld lines are slightly higher than the 031 confluence area and trapezoidal block on both sides, forming a protrusion that affects the flatness.

[0121] Preferably, the merging area 031 is fixedly connected to the trapezoidal block by casting and welding, and an external weld line is formed on one side of the bottom surface of the trapezoidal block in the connection area between the trapezoidal block and the merging area 031.

[0122] Compared with the prior art, the present invention forms an external leakage weld line on one side of the bottom surface of the trapezoidal block in the connection area between the trapezoidal block and the busbar area, which can further ensure the flatness of the outer side of the busbar, save battery space, and effectively avoid short circuits caused by the expansion of the weld line leading to the contact of the active material with the conductive electrode post.

[0123] Preferably, such as Figure 10 As shown, the trapezoidal block has a concave arc-shaped connecting part 021 on one side of its short side; the diameter of the arc-shaped connecting part 021 matches the outer diameter of the conductive terminal 01, and the arc-shaped connecting part 021 arc-shapedly covers the outer wall of the conductive terminal 01 in the area where it connects with the conductive terminal 01.

[0124] Preferably, as an example, such as Figures 6-9 As shown, the trapezoidal block is a trapezoidal block with uniform thickness on both the top and bottom surfaces.

[0125] Specifically, the short side of the trapezoidal block is 20mm to 30mm long, the long side is 40mm to 70mm long, and the thickness is 5mm to 20mm.

[0126] Preferably, the top and bottom surfaces of the trapezoidal block are perpendicular to the side of the busbar near the trapezoidal block, and the top and bottom surfaces of the trapezoidal block are perpendicular to the side of the terminal post.

[0127] Preferably, the bottom surface of the conductive terminal 01 is flush with the bottom surface of the trapezoidal block, and the top end face of the busbar 03 is flush with the top surface of the trapezoidal block. This design can make the most of the internal space of the battery case and effectively improve the volumetric energy density.

[0128] Preferably, the screw connection 02 and the conductive terminal 01 are integrally die-cast.

[0129] Specifically, such as Figure 13As shown, the conductive terminal 01 includes a column 011 and a core 012. The core 012 is nested inside the concave cavity of the column 011. The outer wall of the core 012 and the inner wall of the column 011 are matched and connected to achieve a good conductive path.

[0130] Preferably, the column 011 and the core 012 are integrally formed by die casting.

[0131] Preferably, the core 012 has a screw hole 013 in the central recessed area. The screw hole 013 has threads that can be quickly connected with a matching bolt, which facilitates simple and efficient connection during battery formation or use, and avoids loosening of conductive post connections and increased contact resistance caused by poor contact.

[0132] In the prior art, poor contact can lead to loose connections of conductive posts and increased contact resistance, resulting in increased voltage drop, power loss and insufficient battery charging. Furthermore, due to the increased contact resistance, the temperature of the conductive post can rise sharply when a large current is applied, causing the connection between the conductive post and the screw connection 02 to melt.

[0133] Compared with the prior art, the present invention provides a screw hole in the recessed area of ​​the core, and the screw hole has threads that can be quickly connected with a matching bolt, which facilitates simple and efficient connection during battery formation or use, and avoids loosening of conductive post connection and increased contact resistance caused by poor contact.

[0134] Preferably, the diameter of the core 012 is 10mm to 30mm, and the diameter of the column 011 is 20mm to 40mm.

[0135] Preferably, the height of the column 011 is 30mm to 50mm.

[0136] Preferably, the screw hole 013 has a depth of 15mm to 30mm and a diameter of 5mm to 10mm.

[0137] Preferably, the outer periphery of the column 011 is provided with one or more annular grooves, and the annular grooves are matched with annular O-rings, which can realize the sealed connection between the conductive terminal 01 and the outside.

[0138] Preferably, the width of the annular groove is 2mm to 5mm and the depth is 1mm to 3mm.

[0139] The end of the positive electrode plate in electrode plate 9 is connected to the conductive rib 032 of the positive busbar 10 through the busbar connector 8; the end of the negative electrode plate in electrode plate 9 is connected to the conductive rib 032 of the negative busbar 11 through the busbar connector 8.

[0140] The following specific embodiments further illustrate the injection-molded frame for the busbar grid, the busbar grid, the electrode plate, and the composite energy storage battery of the present invention.

[0141] Example 1

[0142] This embodiment provides an injection-molded frame, a busbar grid, and an electrode plate.

[0143] The injection-molded frame for the busbar grid includes a first frame 1 near the casting and welding area, a second frame 2 opposite to and parallel to the first frame 1, a third frame 3 connecting one end of the first frame 1 and one end of the second frame 2, and a fourth frame 4 connecting the other end of the first frame 1 and the other end of the second frame 2, wherein the third frame 3 and the fourth frame 4 are parallel.

[0144] The first frame 1 and the second frame 2 are provided with an equal number of corresponding lead wire holes 5. The lead wire holes 5 on the first frame 1 are arranged in a single layer. The lead wire holes 5 on the second frame 2 are arranged in two layers, and the lead wire holes in adjacent layers are staggered. On the second frame 2, the height h of the overlapping part of the two adjacent layers of lead wire holes in the direction perpendicular to the electrode plane is 1 / 3 of the diameter of the lead wire hole.

[0145] The thickness of the first frame 1 gradually decreases along the outward extension direction, forming a trapezoidal cross-section. The trapezoidal cross-section of the first frame 1 gradually arranges the two layers of lead wire into a single layer. The height of the trapezoidal cross-section is based on the lead wire reserved for the thickness of the manifold during casting and welding. The height of the trapezoidal cross-section ensures that the composite lead wire reserved during the casting and welding of the manifold is buried in the lead molten metal of the manifold, with no excess composite lead wire exposed to the acidic environment.

[0146] The injection-molded frame for the busbar grid also includes multiple horizontal ribs 6 disposed within a square frame enclosed by four side frames. The horizontal ribs 6 are parallel to the first side frame 1 and are evenly distributed. The cross-sections of the second side frame 2, the third side frame 3, the fourth side frame 4, and the horizontal ribs 6 are all rhomboid. A pair of opposite diagonals in the rhomboid structure of the second side frame 2, the third side frame 3, the fourth side frame 4, and the horizontal ribs 6 respectively face two sides of the electrode plate.

[0147] The thickness of the first frame 1, the second frame 2, the third frame 3 and the fourth frame 4 is 0.5 mm less than the thickness of the electrode plate and 0.3 mm greater than the thickness of the transverse rib 6.

[0148] The busbar grid includes lead wire 7 and the injection-molded frame for the busbar grid. The lead wire intersects the horizontal ribs perpendicularly. The double-layer lead wires between the second frame and the horizontal ribs near the first frame are arranged in parallel. The lead wires between the horizontal ribs near the first frame and the first frame are gradually arranged into a single layer of lead wires from the horizontal ribs near the first frame towards the first frame. The lead wires 7 pass through the corresponding lead wire holes of the first frame 1 and the second frame 2 respectively. The lead wires are perpendicularly connected to the horizontal ribs 6, forming a grid in the frame. The side of the lead wire near the electrode surface where it intersects with the horizontal rib is not completely covered by the injection molding compound. The height of the part of the lead wire not covered by the injection molding compound is equal to 1 / 3 of the lead wire diameter. The end of the lead wire 7 near the casting and welding area extends beyond the outer edge of the first frame 1. The lead wire is a composite lead wire.

[0149] The electrode plate includes the aforementioned busbar grid and active material.

[0150] Example 2

[0151] This embodiment provides a composite energy storage battery, which includes a positive electrode busbar, a negative electrode busbar, multiple battery cells, and multiple plates from Embodiment 1.

[0152] The electrode plates and battery cells are stacked alternately.

[0153] The battery cell has two sides with opposite polarities;

[0154] Adjacent battery cells with the same electrode polarity are arranged facing each other and connected by electrode plates;

[0155] The electrode plates include a positive electrode plate and a negative electrode plate;

[0156] The end of the positive electrode plate is connected to the positive electrode busbar via a connector;

[0157] The end of the negative plate is connected to the negative busbar via a connector.

[0158] The composite energy storage battery has 19 positive plates and 20 negative plates, with a plate spacing of 0.2 mm and a plate height H2 of 117 mm. The required busbars are designed according to the requirements of the composite energy storage battery.

[0159] S1: Based on the number of grids, the number of conductive ribs in the positive busbar 1a is determined to be 19, the number of conductive ribs in the negative busbar 1b is 20, and the distance between the conductive ribs of the two busbars is 0.2mm;

[0160] S2: Based on the functional relationship between H and X: H = aX 2 +bX+c, where a=0.005, b=-1, c=180, determine the height H of the longitudinal centerline of each conductive rib in the busbar;

[0161] S3: Select a lead wire with a diameter of 2.0 mm as the busbar for connecting the electrode plate and the conductive rib. Determine the number of busbars to be 14. Select a rectangle with a cross-sectional area of ​​S0 = 7.6 mm × 0.2 mm at the free end. The distance between the first busbar and the second busbar is L0 = H2 / (n+1) = 7.8 mm, and H2 is 117 mm.

[0162] S4: The cross-sectional area of ​​the end where the conductive rib connects to the busbar is Smax = S0 × n = 21.28 mm. 2 The cross-sectional area of ​​the conductive rib is S = S0 + (Smax - S0) × (L - L0) / (Lmax - L0).

[0163] The short side of the trapezoidal block is 20mm long, the long side is 40mm long, and the thickness is 20mm.

[0164] The core has a diameter of 30mm, and the column has a diameter of 40mm.

[0165] The height of the column is 50mm.

[0166] The screw hole has a depth of 30mm and a diameter of 10mm.

[0167] The height difference between the top of the busbar area and the highest point of each conductive rib is H1 = 12 mm, and the design current density of the conductive rib is 3.0 A / mm². 2 .

[0168] The outer circumference of the column is provided with three annular grooves, and the annular grooves are matched with annular O-rings to achieve a sealed connection between the conductive terminal and the outside.

[0169] The annular groove is 4mm wide and 3mm deep.

[0170] Two busbars of the above-mentioned size are selected as the positive and negative busbars of the composite energy storage battery, and the composite energy storage battery is prepared with battery cells and plates, with the plates and battery cells stacked alternately.

[0171] The battery cell has 19 plates with opposite polarities on both sides. The electrodes of adjacent battery cells with the same polarity are arranged facing each other and connected by plates. The battery cell has a design capacity of 633.33Ah, with 19 positive plates and 20 negative plates, each plate providing a capacity of 33.333Ah.

[0172] The end of the positive electrode plate in the electrode plate is connected to the positive electrode busbar through a bus connector and conductive ribs;

[0173] The end of the negative electrode plate in the electrode plate is connected to the negative electrode busbar through a bus connector and conductive ribs.

[0174] The aforementioned composite energy storage battery underwent a 250A charge and 250A discharge test. After 88 system cycles, the discharge energy efficiency was 93%; the energy density (10hr) was 97Wh / L; the energy storage cost per kilowatt-hour (battery) was 0.21 yuan / kWh; the total capacity per charge was 610.24Ah; the capacity per discharge was 598.97Ah; the charge factor was 103.97%; and the active material utilization rate was 39%. During the casting and welding of the lead wire to the conductive ribs of the busbar, two out of 150 welding points required rework.

[0175] Example 3

[0176] This embodiment provides a composite energy storage battery similar to that of Embodiment 2, except that the height h of the overlapping portion of the two adjacent lead wire holes in the direction perpendicular to the electrode surface is 1 / 4 of the diameter of the lead wire hole.

[0177] The composite energy storage battery was subjected to a 250A charge and 250A discharge test. After 88 system cycles, the total single charge capacity was 602.51Ah, the single discharge capacity was 580.32Ah, the energy density (10hr) was 96Wh / L, the energy storage cost per kilowatt-hour (battery) was 0.22 yuan / kWh, the charge factor was 103.21%, the C0.5 discharge efficiency was 91%, and the active material utilization rate was 37%.

[0178] Comparative Example 1

[0179] This comparative example provides a composite energy storage battery similar to Example 2, except that the composite lead wire in the grid is set as a single layer, that is, the lead wire holes in the first and second frames are both a single layer. The rest is the same as in Example 2.

[0180] The above-mentioned composite energy storage battery was subjected to a 250A charge and 250A discharge test. After 88 system cycles, the discharge energy efficiency was 89%; the energy density (10hr) was 95Wh / L; the energy storage cost (battery) was 0.229 yuan / kWh; the total capacity of a single charge was 594.61Ah; the capacity of a single discharge was 579.77Ah; the charge factor was 102.11%; and the utilization rate of active material was 35%.

[0181] Comparative Example 2

[0182] This embodiment provides a composite energy storage battery, which includes a positive busbar, a negative busbar, multiple battery cells, and multiple plates; the composite lead wire in the grid of the plate is set as one layer, that is, the lead wire holes of the first frame and the second frame are both one layer.

[0183] The electrode plates and battery cells are stacked alternately.

[0184] The battery cell has two sides with opposite polarities;

[0185] Adjacent battery cells with the same electrode polarity are arranged facing each other and connected by electrode plates;

[0186] The electrode plates include a positive electrode plate and a negative electrode plate;

[0187] The end of the positive electrode plate is connected to the positive electrode busbar via a connector;

[0188] The end of the negative plate is connected to the negative busbar via a connector.

[0189] The composite energy storage battery has 15 positive plates and 16 negative plates, with a plate spacing of 0.2 mm and a plate height H2 of 117 mm. The required busbars are designed according to the requirements of the composite energy storage battery.

[0190] S1: Based on the number of grids, the number of conductive ribs in the positive busbar is determined to be 15, the number of conductive ribs in the negative busbar is 16, and the distance between the conductive ribs of the two busbars is 0.2mm;

[0191] S2: As Figure 14 As shown, according to the functional relationship between H and X: H = aX 2 +bX+c, where a=0.0025, b=-0.5272, c=175.71, determine the height H of the longitudinal centerline of each conductive rib in the busbar;

[0192] S3: Select a lead wire with a diameter of 2.0 mm as the busbar for connecting the electrode plate and the conductive rib. Determine the number of busbars to be 14. Select a rectangle with a cross-sectional area of ​​S0 = 7.6 mm × 0.2 mm at the free end. The distance between the first busbar and the second busbar is L0 = H2 / (n+1) = 7.8 mm, and H2 is 117 mm.

[0193] S4: The cross-sectional area of ​​the end where the conductive rib connects to the busbar is Smax = S0 × n = 21.28 mm. 2 The cross-sectional area of ​​the conductive rib is S = S0 + (Smax - S0) × (L - L0) / (Lmax - L0).

[0194] The short side of the trapezoidal block is 26mm long, the long side is 54mm long, and the thickness is 10mm.

[0195] The core has a diameter of 20mm, and the column has a diameter of 26mm.

[0196] The height of the column is 40mm.

[0197] The screw hole has a depth of 22mm and a diameter of 8mm.

[0198] The height difference between the top of the busbar area and the highest point of each conductive rib is H1 = 11 mm, and the design current density of the conductive rib is 2.5 A / mm².2 .

[0199] The outer circumference of the column is provided with three annular grooves, and the annular grooves are matched with annular O-rings to achieve a sealed connection between the conductive terminal and the outside.

[0200] The annular groove is 3mm wide and 2mm deep.

[0201] Two busbars of the above-mentioned size are selected as the positive and negative busbars of the composite energy storage battery, and the composite energy storage battery is prepared with battery cells and electrode plates, with the electrode plates and battery cells stacked alternately.

[0202] The battery cell has 15 plates with opposite polarities on both sides. Adjacent battery cells with the same polarity on one side face each other and are connected by electrode plates. The battery cell has a design capacity of 500Ah, with 15 positive plates and 16 negative plates, and each plate provides a capacity of 33.333Ah.

[0203] The end of the positive electrode plate in the electrode plate is connected to the positive electrode busbar through a bus connector and conductive ribs;

[0204] The end of the negative electrode plate in the electrode plate is connected to the negative electrode busbar through a bus connector and conductive ribs.

[0205] The above-mentioned composite energy storage battery was charged at 250A (I2) and discharged at 250A (C0.5) for 88 cycles, as follows: Figure 15a As shown, the total capacity for a single charge is 469.429 Ah; the capacity for a single discharge is 457.715 Ah; the energy density (10hr) is 94.8 Wh / L; the energy storage cost per kilowatt-hour (battery) is 0.231 yuan / kWh; the charging factor is 102.9%; and the C0.5 discharge efficiency is 97.5%.

[0206] Where I2 represents a 500Ah battery being charged at 250A; discharge capacity is represented by C, where C0.5 equals a discharge current of 500Ah × 0.5.

[0207] Comparative Example 3

[0208] This embodiment provides a composite energy storage battery, which includes a positive busbar, a negative busbar, multiple battery cells, and multiple plates; the composite lead wire in the grid of the plate is set as one layer, that is, the lead wire holes of the first frame and the second frame are both one layer.

[0209] The electrode plates and battery cells are stacked alternately.

[0210] The battery cell has two sides with opposite polarities;

[0211] Adjacent battery cells with the same electrode polarity are arranged facing each other and connected by electrode plates;

[0212] The electrode plates include a positive electrode plate and a negative electrode plate;

[0213] The end of the positive electrode plate is connected to the positive electrode busbar via a connector;

[0214] The end of the negative plate is connected to the negative busbar via a connector.

[0215] The composite energy storage battery has 11 positive plates and 12 negative plates, with a plate spacing of 0.2 mm and a plate height H2 of 117 mm. The required busbar is designed according to the requirements of the composite energy storage battery.

[0216] S1: Based on the number of grids, the number of conductive ribs in the positive busbar is determined to be 11, the number of conductive ribs in the negative busbar is 12, and the distance between the conductive ribs of the two busbars is 0.2mm;

[0217] S2: Based on the functional relationship between H and X: H = aX 2 Given a = 0.0025, b = -0.6, and c = 170, determine the height H of the longitudinal centerline of each conductive rib in the busbar.

[0218] S3: Select a lead wire with a diameter of 2.0 mm as the busbar for connecting the electrode plate and the conductive rib. Determine the number of busbars to be 14. Select a rectangle with a cross-sectional area of ​​S0 = 7.6 mm × 0.2 mm at the free end. The distance between the first busbar and the second busbar is L0 = H2 / (n+1) = 7.8 mm, and H2 is 117 mm.

[0219] S4: The cross-sectional area of ​​the end where the conductive rib connects to the busbar is Smax = S0 × n = 21.28 mm. 2 The cross-sectional area of ​​the conductive rib is S = S0 + (Smax - S0) × (L - L0) / (Lmax - L0).

[0220] The short side of the trapezoidal block is 20mm long, the long side is 40mm long, and the thickness is 5mm.

[0221] The core has a diameter of 10mm, and the cylinder 011 has a diameter of 20mm.

[0222] The height of the column is 30mm.

[0223] The screw hole has a depth of 15mm and a diameter of 5mm.

[0224] The outer circumference of the column is provided with two annular grooves, and the annular grooves are matched with annular O-rings to achieve a sealed connection between the conductive terminal and the outside.

[0225] The annular groove is 2mm wide and 1mm deep.

[0226] The height difference between the top of the busbar area and the highest point of each conductive rib is H1 = 13.5 mm, and the design current density of the conductive rib is 2.8 A / mm². 2 .

[0227] Two busbars of the above-mentioned size are selected as the positive and negative busbars of the composite energy storage battery, and the composite energy storage battery is prepared with battery cells and plates, with the plates and battery cells stacked alternately.

[0228] The battery cell has 11 plates with two sides of opposite polarity. The electrodes of adjacent battery cells with the same polarity are arranged facing each other and connected by plates. The battery cell has a design capacity of 366Ah, with 11 positive plates and 12 negative plates, each plate providing a capacity of 33.333Ah.

[0229] The end of the positive electrode plate is connected to the positive busbar via a bus connector and conductive ribs;

[0230] The end of the negative electrode plate is connected to the negative busbar via a bus connector and conductive ribs.

[0231] The above-mentioned composite energy storage battery was charged at 250A and discharged at 250A. After 88 cycles, the total capacity of a single charge was 342.513Ah, the capacity of a single discharge was 336.13Ah, the energy density (10hr) was 95.2Wh / L, the energy storage cost per kilowatt-hour (battery) was 0.231 yuan / kWh, the charging factor was 103.1%, and the discharge efficiency was greater than 98.21%.

[0232] Comparative Example 4

[0233] This comparative example provides a composite energy storage battery, wherein the height H of the center line of the longitudinal axis of the conductive ribs is equal to aX. 2 +bX+c, where a=0.002, b=-0.5272, c=175.71, and the rest are the same as in comparative example 2.

[0234] Two busbars of the above-mentioned size were selected as the positive and negative busbars of the composite energy storage battery. The composite energy storage battery was prepared according to the same method as Comparative Example 2. The composite energy storage battery was charged at 250A and discharged at 250A. After 88 cycles, the total single charge capacity was 468.318Ah, the single discharge capacity was 437.877Ah, the charge factor was 102.9%, and the C0.5 discharge efficiency was greater than 93.50%.

[0235] Comparative Example 5

[0236] This comparative example provides a composite energy storage battery, wherein the height H of the center line of the longitudinal axis of the conductive ribs is equal to aX. 2+bX+c, where a=0.0025, b=-0.4, c=175.71, and the rest are the same as in comparative example 2.

[0237] Two busbars of the above-mentioned size were selected as the positive and negative busbars of the composite energy storage battery. The composite energy storage battery was prepared according to the same method as Comparative Example 2. The composite energy storage battery was charged at 250A and discharged at 250A. After 88 cycles, the total single charge capacity was 469.121Ah, the single discharge capacity was 433.61Ah, the charge factor was 102.9%, and the C0.5 discharge efficiency was greater than 92.43%.

[0238] Comparative Example 6

[0239] This comparative example provides a composite energy storage battery, H = aX 2 +bX+c, where a=0.0025, b=-0.5272, c=190, and the rest are the same as in comparative example 2.

[0240] Two busbars of the above-mentioned size were selected as the positive and negative busbars of the composite energy storage battery. The composite energy storage battery was prepared according to the same method as in Comparative Example 2. The composite energy storage battery was charged at 250A and discharged at 250A. After 88 cycles, the total single charge capacity was 467.882Ah, the single discharge capacity was 427.878Ah, the charge factor was 102.9%, and the C0.5 discharge efficiency was greater than 91.45%.

[0241] Comparative Example 7

[0242] This comparative example provides a composite energy storage battery, where the height of the conductive ribs is taken as the maximum value of the conductive rib height in Comparative Example 2, and the rest is the same as Comparative Example 2.

[0243] Two busbars of the above-mentioned size were selected as the positive and negative busbars of the composite energy storage battery. The composite energy storage battery was prepared using the same method as in Comparative Example 2. The composite energy storage battery was charged at 250A and discharged at 250A for 88 cycles. [The following appears to be a separate, unrelated sentence:] ... Figure 15b As shown, the total charging capacity is 486.502Ah, with a retention rate of 112% relative to the theoretical design value; the discharge capacity is 448.172Ah, with a retention rate of 110% relative to the theoretical design value; and the discharge efficiency is 91.88%.

[0244] contrast Figure 15a , 15b It can be seen that, compared with Comparative Example 7, the discharge efficiency of Comparative Example 2 is significantly higher than that of the conductive ribs and other components in Comparative Example 7 after multiple cycles.

[0245] Comparative Example 8

[0246] This comparative example provides a composite energy storage battery. The height of the conductive ribs is taken as the maximum value of the conductive rib thickness / cross-sectional area in Comparative Example 2. Each conductive rib requires nearly twice the amount of lead material (as can be seen from the cubic volume formula). The rest is the same as Comparative Example 2.

[0247] Two busbars of the above-mentioned size were selected as the positive and negative busbars of the composite energy storage battery. The composite energy storage battery was prepared according to the same method as Comparative Example 2. The composite energy storage battery was charged at 250A and discharged at 250A. After 88 cycles, the total single charge capacity was 469.433Ah; the single discharge capacity was 457.0Ah; the charge factor was 101.8%; and the C0.5 discharge efficiency was 97.53%.

[0248] Compared to Comparative Example 2, Comparative Example 8 did not show a substantial improvement in discharge efficiency, and each conductive rib required nearly twice the amount of lead material.

[0249] Compared with existing technologies that collect current from each electrode plate through tabs, the current collection grid of this invention has multiple individually working conductive ribs to make the current distribution more uniform. It can collect current over a larger area on the side of each electrode plate, thus significantly improving working efficiency under high power conditions, rather than being limited to the contact area between the tabs and the electrode plates in existing technologies. Therefore, it can reduce electrical losses and improve reliability.

[0250] Comparative Example 9

[0251] This comparative example provides a composite energy storage battery similar to that of Example 2, except that both the first and second frames are provided with two layers of lead wire holes, that is, the lead wires near the casting and welding area are provided in two layers.

[0252] When the lead wire was cast and welded to the conductive ribs of the busbar, 4 out of 150 welding points required rework.

[0253] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A busbar grid, characterized in that, The busbar grid includes lead wire (7) and a molded frame for the busbar grid; The injection-molded frame for the busbar includes a first frame (1) near the casting area, a second frame (2) opposite to and parallel to the first frame (1), a third frame (3) connecting one end of the first frame (1) and one end of the second frame (2), and a fourth frame (4) connecting the other end of the first frame (1) and the other end of the second frame (2), wherein the third frame (3) and the fourth frame (4) are parallel. The first frame (1) and the second frame (2) are provided with an equal number of wire holes (5); the wire holes (5) on the first frame (1) are arranged in a single layer; the wire holes (5) on the second frame (2) are arranged in at least two layers, and the wire holes between adjacent layers are staggered. The injection-molded frame for the busbar grid also includes a plurality of horizontal ribs (6) set within a square frame enclosed by four side borders, the horizontal ribs (6) being parallel to the first side border (1); the lead wire (7) intersects the horizontal ribs (6) perpendicularly; The multi-layered lead wires between the second frame (2) and the horizontal rib (6) near the first frame (1) are arranged in parallel. The lead wire (7) between the horizontal rib (6) near the first frame (1) and the first frame (1) is gradually arranged into a single layer of lead wire (7) from the horizontal rib (6) near the first frame (1) toward the first frame (1).

2. The busbar grid according to claim 1, characterized in that, The side of the lead wire (7) near the electrode plate surface where it intersects with the transverse rib (6) is not completely covered by injection molding.

3. The busbar grid according to claim 1, characterized in that, On the second frame (2), the vertical distance between the centers of two adjacent wire holes (5) is less than the diameter of the wire hole (5).

4. The busbar grid according to claim 1, characterized in that, The thickness of the first frame (1) gradually decreases along the outward extension direction, forming a trapezoidal cross section.

5. The busbar grid according to claim 1, characterized in that, The cross sections of the second border (2), the third border (3), the fourth border (4) and the horizontal rib (6) are all rhomboid.

6. An electrode plate, characterized in that, The electrode plate comprises the busbar grid and active material as described in any one of claims 1-5.

7. A composite energy storage battery, characterized in that, The composite energy storage battery includes a positive electrode busbar, a negative electrode busbar, multiple battery cells, and multiple electrode plates as described in claim 6; The electrode plates and battery cells are stacked alternately. The battery cell has two sides with opposite polarities; Adjacent battery cells with the same electrode polarity are arranged facing each other and connected by electrode plates; The electrode plates include a positive electrode plate and a negative electrode plate; The end of the positive electrode plate is connected to the positive electrode busbar via a connector; The end of the negative plate is connected to the negative busbar via a connector.

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