Battery shell assembly and battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery shell assembly and a battery, and the battery shell assembly comprises a battery shell, a combined plastic part, a connecting piece and a pole. The pole group is located in an installation cavity of the battery shell, the combined plastic part is installed on the wall, provided with a first installation hole, of the battery shell, the connecting piece is located on the side, away from the battery shell, of the combined plastic part, the connecting piece is fixed to the combined plastic part through ultrasonic hot melting, and a pole lug of the pole group penetrates through the first installation hole and the combined plastic part and then is connected with the connecting piece; the pole is positioned on one side, deviating from the battery shell, of the connecting piece. The connecting sheet and the pole are arranged outside the mounting cavity of the battery shell, so that the internal space of the battery shell is not occupied, the arrangement space of the pole group is increased, the space utilization rate of the mounting cavity is high, and the energy density of the battery is favorably improved. The invention also provides a battery which comprises the battery shell assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery housing assembly and a battery. Background Art

[0002] In lithium-ion batteries, the connecting piece and one end of the pole are generally arranged in the battery housing, and the other end of the pole passes through the battery housing and is connected to the external circuit to lead out the pole group to realize the power supply or energy storage of the battery. A lower plastic part is arranged between the end of the pole located in the battery housing and the battery housing, and the pole is insulated from the battery housing by the lower plastic part, and the lower plastic part is also located in the battery housing.

[0003] Since one end of the connecting piece and the pole is arranged in the battery shell, the connecting piece and the pole will occupy part of the space inside the battery shell, the arrangement space of the pole group is small, the space utilization rate inside the battery shell is low, and the energy density of the battery is low. Summary of the invention

[0004] The object of the present invention is to provide a battery housing assembly and a battery, wherein the connecting pieces and poles do not need to occupy the internal space of the battery housing, the arrangement space of the pole group is increased, the space utilization rate is high, and it is beneficial to improve the energy density of the battery.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a battery housing assembly, comprising:

[0007] A battery housing, wherein the interior is hollow to form a mounting cavity, one side of the battery housing has an opening communicating with the mounting cavity, the electrode group is loaded into the mounting cavity through the opening, and a first mounting hole is provided on one wall of the battery housing;

[0008] A combined plastic part, partly located outside the mounting cavity and attached to the end surface of the battery housing away from the electrode group, and partly located inside the mounting cavity and attached to the end surface of the battery housing close to the electrode group, wherein the combined plastic part is provided with a through hole;

[0009] A connecting piece is located on a side of the combined plastic part away from the battery housing, the connecting piece is fixed to the combined plastic part by hot melting, and the pole lug of the pole group is connected to the connecting piece after passing through the first mounting hole and the through hole;

[0010] The pole is located on a side of the connecting piece away from the battery housing, and the pole is connected to the connecting piece.

[0011] Optionally, the battery housing includes a top wall and a peripheral side wall, the top wall and the peripheral side wall surround the mounting cavity, and the first mounting hole is provided on the top wall.

[0012] Optionally, the combined plastic part comprises a first plastic part body and a second plastic part body, the first plastic part body and the second plastic part body are both provided with the through hole, the first plastic part body is located outside the installation cavity and is attached to the end surface of the top wall away from the pole group, and the second plastic part body is located inside the installation cavity and is attached to the end surface of the top wall close to the pole group;

[0013] And / or, one of the first plastic body and the second plastic body is provided with a first flange, the first flange is located in the circumference of the through hole, the first flange is penetrated into the first mounting hole and fits with the inner wall of the first mounting hole.

[0014] Optionally, a pole ear shaping structure is provided on one side of the second plastic component body close to the pole group, and the pole ear shaping structure includes two guide plates, the two guide plates are respectively arranged on both sides of the through hole, and the two guide plates are inclined in the direction away from the axis of the through hole, and along the direction away from the through hole, an open and gradually widening bell mouth is formed between the two guide plates, the large end of the bell mouth faces the pole group, and the small end of the bell mouth is connected to the second plastic component body, and the pole ear is inserted into the bell mouth.

[0015] Optionally, the angle between the guide plate and the axis of the through hole is α, and the value range of α is 45°≤α≤87°.

[0016] Optionally, a support structure is provided on one side of the second plastic body close to the top wall, the support structure comprises a connecting plate and a support plate, the connecting plate is connected to the tab shaping structure, the support plate is arranged on an end surface of the connecting plate close to the top wall, and the support plate abuts against the top wall;

[0017] Wherein, along the first direction, the distance between the end surface of the support plate facing away from the guide plate and the end of the guide plate close to the support plate is e, and the value range of e is 0.5mm≤e≤20mm;

[0018] And / or, along the second direction, a distance between an end surface of the connecting plate facing away from the top wall and an end surface of the second plastic component body facing away from the top wall is f, and a value range of f is 0 mm ≤ f ≤ 5 mm.

[0019] Optionally, a lap portion is provided in the circumference of the first plastic body, a sink groove is provided on the end surface of the top wall facing away from the second plastic body, and the lap portion is embedded in the sink groove and fits with the bottom wall of the sink groove;

[0020] Wherein, along the second direction, the thickness of the top wall is H, the distance between the end surface of the overlap portion away from the second plastic component body and the end surface of the top wall away from the second plastic component body is b, and the value range of b satisfies: -1mm≤b≤0.5H, 1mm≤H≤3mm;

[0021] And / or, along the first direction and the third direction, the width of the overlapping portion is c, and the value range of c satisfies: 0mm≤c≤10mm.

[0022] Optionally, a second flange and a connecting rib are provided on the side of the first plastic component body facing away from the pole group, the second flange is arranged in the circumference of the through hole, the connecting rib is connected to the second flange, the second flange, the connecting rib and the first plastic component body form an installation groove, and at least a part of the connecting piece is embedded in the installation groove.

[0023] Optionally, one of the connecting piece and the combined plastic part is provided with a fusion column, and the other of the connecting piece and the combined plastic part is provided with a fixing hole, and the fusion column is fixed to the fixing hole by hot melting.

[0024] On the other hand, the present invention provides a battery, comprising a base plate, a pole group, and a battery housing assembly in any of the above schemes, wherein the base plate is connected to an opening of the battery housing, and the pole group is encapsulated in a mounting cavity of the battery housing.

[0025] The beneficial effects of the present invention are:

[0026] The present invention provides a battery shell assembly, including a battery shell, a combined plastic part, a connecting piece and a pole. The pole group is located in the installation cavity of the battery shell, the combined plastic part is installed on the wall of the battery shell provided with a first installation hole, the connecting piece is located on the side of the combined plastic part away from the battery shell, and the connecting piece is fixed to the combined plastic part by ultrasonic hot melting, a through hole is provided on the combined plastic part, the pole ear of the pole group passes through the first installation hole and the through hole and is connected to the connecting piece, the pole post is located on the side of the connecting piece away from the battery shell, and the connecting piece can be insulated from the battery shell and the pole group can be insulated from the battery shell by the combined plastic part. Since the connecting piece and the pole post are both arranged outside the installation cavity of the battery shell, the connecting piece and the pole post will not occupy the internal space of the battery shell, the arrangement space of the pole group is increased, the space utilization rate of the installation cavity is high, and it is beneficial to improve the energy density of the battery. In addition, the connecting piece and the pole post are both flat, and the overall volume of the battery shell assembly is small. When the battery with the battery shell assembly is arranged in a whole pack of batteries, the space utilization rate is high and the energy density is large.

[0027] The present invention also provides a battery, including a bottom plate, a pole group, and the above-mentioned battery housing assembly, wherein the bottom plate is connected to the opening of the battery housing to encapsulate the pole group in the mounting cavity of the battery housing. The pole lugs of the pole group can be led out through the battery housing assembly, and are connected to the pole posts through the connecting pieces, and then the pole posts are connected to the external circuit, so that the pole group can supply power to the external circuit or store energy. Since the connecting pieces and the pole posts are both arranged outside the mounting cavity of the battery housing, the space utilization rate inside the battery housing is high, the volume of the pole group is increased, and the energy density of the battery is high. In addition, the connecting pieces and the pole posts are both flat, and the overall volume of the battery housing is small, which is conducive to improving the space utilization rate of the battery in the whole battery pack, and the energy density is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0029] Figure 1 A schematic diagram of the structure of a battery housing assembly provided in an embodiment of the present invention;

[0030] Figure 2 An exploded view of a battery housing assembly provided in an embodiment of the present invention;

[0031] Figure 3 An exploded view of a battery housing assembly provided in an embodiment of the present invention from another perspective;

[0032] Figure 4 A top view of a battery housing assembly provided in an embodiment of the present invention;

[0033] Figure 5 for Figure 4 Sectional view of the AA section;

[0034] Figure 6 for Figure 5 A partial enlarged view of point C in the middle;

[0035] Figure 7 for Figure 4 Sectional view of the middle BB section;

[0036] Figure 8 for Figure 7 A partial enlarged view of point D in the middle;

[0037] Fig. 9 It is a structural schematic diagram of a combined plastic part provided in an embodiment of the present invention;

[0038] Fig.10 It is a structural schematic diagram of the combined plastic part provided in an embodiment of the present invention from another viewing angle;

[0039] Fig.11 It is a schematic diagram of the structure of the connecting piece provided in an embodiment of the present invention.

[0040] In the figure:

[0041] 100, battery housing; 110, top wall; 111, first mounting hole; 112, sink; 113, second mounting hole; 114, support rib; 115, first liquid injection hole; 120, peripheral side wall; 121, opening;

[0042] 200, combined plastic part; 201, through hole; 210, first plastic part body; 211, overlap part; 212, second flange; 213, connecting rib; 2131, mounting groove; 214, fuse column; 2141, convex part; 220, second plastic part body; 221, first flange; 222, tab shaping structure; 2221, guide plate; 2222, bell mouth; 223, supporting structure; 2231, connecting plate; 2232, supporting plate; 224, vent hole;

[0043] 300, connecting piece; 301, fixing hole; 3011, sinking platform;

[0044] 400. Explosion-proof valve. DETAILED DESCRIPTION

[0045] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0049] like Figure 1-Figure 3As shown, this embodiment provides a battery housing assembly, which includes a battery housing 100, a combined plastic part 200, a connecting piece 300 and a pole. The battery housing 100 is hollow inside to form an installation cavity, one side of the battery housing 100 has an opening 121 connected to the installation cavity, the pole group is loaded into the installation cavity through the opening 121, and a first installation hole 111 is provided on one wall of the battery housing 100. A portion of the combined plastic part 200 is located outside the installation cavity and fits to the end face of the battery housing 100 away from the pole group, the connecting piece 300 is located on the side of the combined plastic part 200 away from the battery housing 100, thereby the connecting piece 300 can be insulated from the battery housing 100 through the combined plastic part 200, and a portion of the combined plastic part 200 is located in the installation cavity and fits to the end face of the battery housing 100 close to the pole group, thereby the combined plastic part 200 can insulate the pole group from the battery housing 100.

[0050] Furthermore, in this embodiment, the composite plastic part 200 is provided with a through hole 201, and the connecting piece 300 is fixed to the composite plastic part 200 by ultrasonic hot melting, which is simple to assemble and has a good appearance. The connecting piece 300 and the pole are both in the shape of a plate, and the side of the connecting piece 300 close to the battery housing 100 is attached to the part of the composite plastic part 200 located outside the installation cavity. The pole ear of the pole group passes through the first installation hole 111 and the through hole 201 and is connected to the connecting piece 300. The pole is located on the side of the connecting piece 300 away from the battery housing 100 and is attached to the end face of the connecting piece 300 away from the battery housing 100, so that the pole is conductively connected to the connecting piece 300, and the pole group is connected to the external circuit through the connecting piece 300 and the pole, so as to realize the charging and discharging of the pole group.

[0051] Since the connecting piece 300 and the pole are both arranged outside the installation cavity of the battery housing 100, the connecting piece 300 and the pole do not occupy the internal space of the battery housing 100, the arrangement space of the pole group is increased, and the space utilization rate of the installation cavity is high, which is conducive to improving the energy density of the battery. In addition, the connecting piece 300 and the pole are both flat, and the battery housing assembly is arranged along the Figure 1-Figure 3 The size in the Z-axis direction is small, and the volume of the battery housing assembly is small. When the battery with the battery housing assembly is arranged in a whole battery pack, the space utilization rate is high and the energy density is high.

[0052] As an optional solution, the battery housing 100 in this embodiment includes a top wall 110 and a peripheral side wall 120, wherein one end of the peripheral side wall 120 is connected to the top wall 110, and the other end of the peripheral side wall 120 is surrounded to form the above-mentioned opening 121, and the top wall 110 and the peripheral side wall 120 are surrounded to form the above-mentioned installation cavity, and the first installation hole 111 is set on the top wall 110, and the combined plastic part 200 is set on the top wall 110, and the combined plastic part 200 can insulate the connecting piece 300 from the top wall 110, and insulate the pole group from the top wall 110, thereby ensuring the electrical safety of the battery. Alternatively, in other embodiments, the first installation hole 111 can also be set on the peripheral side wall 120, and the combined plastic part 200 is installed on the peripheral side wall 120, and the combined plastic part 200 can insulate the connecting piece 300 from the peripheral side wall 120, and insulate the pole group from the peripheral side wall 120.

[0053] See also Figure 4-Figure 6 ,as well as Fig.11 , one of the connecting piece 300 and the combined plastic part 200 is provided with a fusion column 214, and the other of the connecting piece 300 and the combined plastic part 200 is provided with a fixing hole 301, and the fusion column 214 is fixed in the fixing hole 301 by hot melting, thereby fixing the connecting piece 300 and the combined plastic part 200. Optionally, in this embodiment, the fixing hole 301 is provided on the connecting piece 300, and the fusion column 214 is provided on the side of the combined plastic part 200 facing the connecting piece 300 as an example for description, and this arrangement is convenient for hot melting or hot riveting. After the fusion column 214 on the combined plastic part 200 passes through the fixing hole 301, a convex portion 2141 is formed by hot riveting or hot melting, and the convex portion 2141 abuts against the side of the connecting piece 300 away from the top wall 110, so as to press the connecting piece 300 against the combined plastic part 200, thereby realizing the connection between the connecting piece 300 and the combined plastic part 200. More preferably, a sink 3011 is provided on the end surface of the connecting piece 300 away from the assembled plastic part 200, the sink 3011 is coaxial with the fixing hole 301 and is connected to each other, and the convex portion 2141 formed by hot riveting or hot melting abuts against the bottom wall of the sink 3011, so that the convex portion 2141 does not exceed the end surface of the connecting piece 300 away from the assembled plastic part 200, saving Figure 5 The space in the Z-axis direction is shown in the figure, and the end surface of the connecting piece 300 facing away from the assembled plastic part 200 has no protruding parts, which facilitates the assembly of the connecting piece 300 and the pole.

[0054] Furthermore, in this embodiment, there may be multiple fuses 214 and fixing holes 301, and the fuses 214 correspond to the fixing holes 301 one by one, thereby improving the connection strength between the connecting piece 300 and the combined plastic part 200, and the installation of the connecting piece 300 is more firm and stable. For example, in this embodiment, each connecting piece 300 is provided with two fixing holes 301, and correspondingly, the same number of fuses 214 are provided at corresponding positions on the combined plastic part 200. After the fuses 214 pass through the corresponding fixing holes 301, they are hot-melted or hot-riveted with the connecting piece 300 to connect and fix the two. Optionally, the two fixing holes 301 on the connecting piece 300 are arranged along the Figure 5 They are arranged at intervals in the X-axis direction.

[0055] See also Figure 7-10 In this embodiment, the combined plastic part 200 can be integrally formed by directly injecting the top wall 110 , and can be installed on the top wall 110 after injection molding. The connection between the two is firm, stable, and highly reliable.

[0056] Exemplarily, the combined plastic part 200 includes a first plastic part body 210 and a second plastic part body 220, both of which are provided with through holes 201, the first plastic part body 210 is located outside the installation cavity and is attached to the end face of the top wall 110 away from the pole group, the connecting piece 300 is attached to the end face of the first plastic part body 210 away from the top wall 110, the fuse 214 is arranged on the end face of the first plastic part body 210 facing the connecting piece 300, and the connecting piece 300 is insulated from the top wall 110 by the first plastic part body 210. The second plastic part body 220 is located in the installation cavity and is attached to the end face of the top wall 110 close to the pole group, and the pole group can be insulated from the top wall 110 by the second plastic part body 220. Furthermore, one of the first plastic component body 210 and the second plastic component body 220 is provided with a first flange 221, and the first flange 221 is located in the circumference of the through hole 201. The first plastic component body 210 and the second plastic component body 220 are connected by the first flange 221. The first flange 221 is penetrated into the first mounting hole 111 and fits with the inner wall of the first mounting hole 111. The pole ear of the pole group is penetrated into the through hole 201, and the pole ear is insulated from the inner wall of the first mounting hole 111 by the first flange 221, that is, the first flange 221 insulates the pole ear from the top wall 110.

[0057] Of course, in other embodiments, the first plastic body 210 and the second plastic body 220 can also be separately provided, and the first plastic body 210 and the second plastic body 220 are respectively injection molded by a mold, and then the first plastic body 210 and the second plastic body 220 are respectively installed on both sides of the top wall 110, and the combined plastic part 200 can be removed from the top wall 110, which is more convenient when the combined plastic part 200 needs to be replaced. Optionally, the first flange 221 can be provided on the first plastic body 210, and the first flange 221 and the first plastic body 210 are integrally formed. Or the first flange 221 can also be provided on the second plastic body 220, and the first flange 221 and the second plastic body 220 are integrally formed. Or the first plastic body 210 and the second plastic body 220 can both be provided with the first flange 221, and the two first flanges 221 both extend into the first mounting hole 111 and are mutually sleeved, thereby making the tab and the top wall 110 have a double insulation structure, and the insulation effect is better.

[0058] Furthermore, a pole ear shaping structure 222 is provided on one side of the second plastic body 220 close to the pole group. The pole ear shaping structure 222 includes two guide plates 2221, which are respectively arranged on both sides of the through hole 201 along the first direction, and the two guide plates 2221 are inclined in the direction away from the axis of the through hole 201. In the direction away from the through hole 201, a gradually widened bell mouth 2222 is formed between the two guide plates 2221. The large end of the bell mouth 2222 faces the pole group, and the small end of the bell mouth 2222 is connected to the second plastic body 220. The pole ear is inserted into the bell mouth 2222. During installation, the pole ear is inserted into the through hole 201 from the large end of the bell mouth 2222. In the direction close to the through hole 201, the opening of the bell mouth 2222 gradually shrinks. When the tab is inserted into the bell mouth 2222, the tab can be well gathered into the through hole 201 through the two guide plates 2221. The tab has a good shape in the battery housing 100 and is not prone to short-circuit connection with the battery housing 100, so it has high safety.

[0059] Among them, the angle between the guide plate 2221 and the axis of the through hole 201 is α, and the value range of α is 45°≤α≤87°. Exemplarily, the value of α can be 45°, 50°, 60°, 70°, 80°, 87°, etc. By controlling the value of α within the above range, it can be ensured that the tab shaping structure 222 can well gather the tab in the through hole 201. It should be noted that when the value of α is too large, it will not have a good shaping effect on the tab; when the value of α is too small, it will increase the second plastic body 220 along the Figure 7 The dimension in the Z-axis direction shown in is not conducive to improving the space utilization rate in the installation cavity.

[0060] The following tests are conducted on battery samples in some specific implementation schemes to explore the influence of the value of parameter α on the lug shaping effect. The results are shown in Table 1.

[0061] Table 1

[0062]

[0063] From the test results, it is known that in sample 1, the value of α is smaller than the minimum value of its set range of 45°≤α≤87°. The CT test shows that the tab has a poor retraction effect in the battery housing 100. The tab may be inserted upside down into the pole group, posing a risk of pole group short circuit and resulting in a defective product.

[0064] In Samples 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11, the value of α is within the set range of 45°≤α≤87°. The CT test shows that the tabs have a good retraction effect in the battery case 100, the shape of the tabs is good, and no tabs are found to be inverted into the electrode group. The products are good.

[0065] In sample 12, the value of α is greater than the maximum value of its setting range of 45°≤α≤87°. The CT test shows that the gathering effect of the pole lug in the battery shell 100 is poor, and the pole lug shaping structure 222 has almost no shaping effect on the pole lug. There is a risk of short circuit between the pole lug and the battery shell 100, resulting in a defective product.

[0066] Continue to see Figure 7 and Figure 8 A support structure 223 is further provided on one side of the second plastic body 220 close to the top wall 110. The support structure 223 includes a connecting plate 2231 and a supporting plate 2232. The connecting plate 2231 is connected to the tab shaping structure 222. The supporting plate 2232 is arranged on the end surface of the connecting plate 2231 close to the top wall 110. The supporting plate 2232 abuts against the top wall 110. The tab shaping structure 222 can be well supported by the supporting structure 223, so that the tab shaping structure 222 has a high mechanical strength and is not easily deformed.

[0067] Among them, along the first direction (that is, Figure 7), the distance between the end surface of the support plate 2232 away from the guide plate 2221 and the end of the guide plate 2221 close to the support plate 2232 is e, and the value range of e is 0.5mm≤e≤20mm. Exemplarily, the value of e can be 0.5mm, 1.0mm, 5mm, 10mm, 15mm or 20mm, and can be specifically adjusted according to the size of the second plastic part body 220 along the first direction, which will not be listed here one by one. It should be noted that the value of e should not be too small, otherwise the connecting plate 2231 will be relatively sharp and easily puncture the pole ear or pole group. Of course, the value of e should not be too large, otherwise it will occupy the space of the pole ear shaping structure 222 along the first direction, and the pole ear shaping structure 222 along the second direction (that is, Figure 7 The height in the Z-axis direction (as shown in FIG) increases, which may easily damage the electrode group.

[0068] Furthermore, along the second direction (i.e. Figure 7 ), the distance between the end face of the connecting plate 2231 away from the top wall 110 and the end face of the second plastic body 220 away from the top wall 110 is f, and the value range of f is 0mm≤f≤5mm. Exemplarily, the value of f can be 0mm, 0.5mm, 1.0mm, 2.0mm, 3.0mm, 4.0mm or 5.0mm. It should be noted that the value of f cannot be less than 0mm, otherwise the pole ear shaping structure 222 will protrude from the end face of the second plastic body 220 close to the pole group, which is easy to crush the pole group. The value of f should not be too large, otherwise the inclination angle of the guide plate 2221 is too large, the structure of the pole ear is relatively loose, the pole ear shaping structure 222 has a poor shaping effect on the pole ear, the shape of the pole ear in the battery shell 100 is not good, and it is easy to short-circuit with the battery shell 100.

[0069] The following tests are conducted on battery samples in some specific implementation schemes to explore the influence of the values ​​of parameters e and f on the tab shaping effect. The results are shown in Table 2.

[0070] Table 2

[0071]

[0072] From the test results, it is known that in sample 1, the value of e is smaller than the minimum value of its set range of 0.5mm≤e≤20mm. After disassembling the battery, it was found that the diaphragm at the connecting plate 2231 was damaged and broken, posing a short circuit risk and the product was defective.

[0073] In sample 2, the value of f is smaller than the minimum value of its set range of 0mm≤f≤5mm. After disassembling the battery, it was found that the electrode group at the connecting plate 2231 was crushed and the electrode pieces of the electrode group were powdered, posing a short circuit risk and resulting in a defective product.

[0074] In Sample 3, Sample 4, Sample 5, Sample 6, Sample 7, Sample 8, Sample 9, Sample 10, Sample 11, Sample 12 and Sample 13, the value of e is within its set range of 0.5mm≤e≤20mm, and the value of f is within its set range of 0mm≤f≤5mm. After disassembling the battery, it was found that the diaphragm covering the outside of the electrode group was intact, the electrode group was not crushed, and the shape of the electrode ear in the battery case 100 was good, there was no risk of short circuit, and the product was good.

[0075] In sample 14, the value of e is greater than the maximum value of its set range of 0.5mm≤e≤20mm. The CT test shows that the shape of the pole ear in the battery housing 100 is poor, and the pole ear may be inserted upside down into the pole group, posing a risk of pole group short circuit and a defective product.

[0076] In sample 15, the value of f is greater than the maximum value of its set range of 0mm≤f≤5mm. The size of the second plastic body 220 along the second direction inside the battery case 100 is large, resulting in waste of internal space of the battery case 100, reduced layout space of the pole group, and low energy density of the battery. It is not recommended for use and the product is defective.

[0077] Continue to see Figure 5 , Figure 6 In this embodiment, a lap joint 211 is provided in the circumferential direction of the first plastic body 210, and a recess 112 is provided on the end surface of the top wall 110 facing away from the second plastic body 220. The lap joint 211 is embedded in the recess 112 and fits the bottom wall of the recess 112. On the one hand, the lap joint 211 can be provided along the axial direction (i.e., the first mounting hole 111) of the first mounting hole 111. Figure 6 The first plastic body 210 is limited in position in the Z-axis direction shown in the figure to ensure accurate positioning between the first plastic body 210 and the top wall 110; on the other hand, the arrangement of the sink 112 can further reduce the movement of the battery housing assembly along the second direction (i.e. Figure 6 The size of the battery pack (in the Z-axis direction shown in the figure) is increased, thereby improving the space utilization of the entire battery pack and increasing the energy density.

[0078] Optionally, along the second direction ( Figure 6), the thickness of the top wall 110 is H, the distance between the end surface of the overlapping portion 211 away from the second plastic body 220 and the end surface of the top wall 110 away from the second plastic body 220 is b, and the value range of b satisfies: -1mm≤b≤0.5H, 1mm≤H≤3mm. Wherein "-" indicates that the end surface of the overlapping portion 211 away from the second plastic body 220 exceeds the end surface of the top wall 110 away from the second plastic body 220. Exemplarily, when H is 1mm, the value of b can be -1mm, -0.5mm, 0mm or 0.5mm. It should be noted that the value of b should not be too large. If the value of b is greater than 0.5H, the depth of the sink 112 is large, which affects the mechanical strength of the top wall 110. When the top wall 110 is bumped, it is easy to deform or rupture, resulting in battery failure. The value of b should not be too small. If b<-1mm, the end surface of the overlap portion 211 away from the second plastic body 220 exceeds the end surface of the top wall 110 away from the second plastic body 220 by too much, which is not conducive to improving the space utilization rate and may affect the assembly between the first plastic body 210 and other structural parts. Of course, in other embodiments, the value of H can also be 2mm, 2.5mm or 3mm, etc. The value of b is within the above range and is not listed here one by one.

[0079] See also Figure 6 and Figure 8 , along the first direction ( Figure 8 The Y-axis direction in the Figure 6 In the X-axis direction of the figure, the width of the overlap portion 211 is c, and the value range of c satisfies: 0mm≤c≤10mm. Exemplarily, the value of c can be 0mm, 1mm, 2mm, 5mm, 8mm or 10mm. By controlling the width c of the overlap portion 211 within the above range, it is possible to ensure the stability of the assembly structure between the first plastic part body 210 and the top wall 110, and it is also possible to relatively reduce the weight of the combined plastic part 200 and reduce the material cost. It should be noted that when the width c of the overlap portion 211 is 0mm, the circumferential edge of the first plastic part body 210 overlaps the top wall 110, and at this time, it can also ensure that the first plastic part body 210 and the top wall 110 are successfully assembled. In addition, when the width c of the overlap portion 211 is greater than 10mm, it may occupy more space in the sink 112, affecting the assembly between the top wall 110 and other structural parts.

[0080] The following is a pressure test and a thrust test on the dimension design of the overlap portion 211 and the dimension design of the battery housing 100 using battery samples of different sizes, so as to explore the influence of the above parameters H, b, and c on the insulation performance and structural strength of the battery.

[0081] The withstand voltage test refers to: using an AC withstand voltage tester to load a high voltage (for example, the high voltage may be 1500V) between the battery housing 100 and the first plastic body 210 of the assembled plastic part 200 for 2 seconds, and detecting the leakage current value. When the leakage current value is less than 2mA and the assembled plastic part 200 is not broken down, the insulation performance of the battery is good.

[0082] The thrust test refers to: fix the battery housing 100 and apply a thrust to the assembled plastic part 200 in the direction of the battery housing 100. When the thrust applied to the assembled plastic part 200 is greater than 1200N, and the deformation of the battery housing 100 in the thrust direction is less than 0.5mm, the structural strength of the battery is high and meets the product requirements. The detailed dimensional parameters of the battery and the test results are shown in Table 3 below.

[0083] Table 3

[0084]

[0085] In sample 1, the value of b is -2.0mm, the value of H is 2.0mm, and the value of b is less than the minimum value of -1mm≤b≤0.5H. At this time, the end surface of the overlapping portion 211 that is away from the second plastic component body 220 exceeds the end surface of the top wall 110 that is away from the second plastic component body 220 too much, which affects the height design of the pole along the second direction, is not conducive to improving the energy density of the battery, is not recommended for use, and the product is defective.

[0086] In sample 2, the value of c is -0.5mm, which is less than the minimum value of 0mm≤c≤10mm. Other parameters H and b meet their corresponding size range limits. At this time, the insulation performance between the first plastic part body 210 and the top wall 110 cannot be guaranteed, the voltage withstand test fails, and there is a risk of voltage withstand failure. It is not recommended for use and the product is defective.

[0087] In Sample 3, Sample 4, Sample 5, Sample 6, Sample 7, Sample 8, Sample 9, Sample 10, Sample 11, Sample 12, Sample 13, Sample 14 and Sample 15, the values ​​of parameters H, b, and c all meet their corresponding size range limits. At this time, the insulation performance between the first plastic part body 210 and the top wall 110 is good, the pressure test is passed, and the structural strength of the battery casing 100 is high, and the thrust test is passed. It is recommended for use and the product is good.

[0088] In sample 16, the value of c is 13.0mm, and the value of c is greater than the maximum value of 0mm≤c≤10mm. Other parameters H and b meet their corresponding size range limits. At this time, the insulation performance between the first plastic part body 210 and the top wall 110 is good, and the voltage test is passed. However, the width of the overlapping portion 211 of the first plastic part body 210 is large, and the material used for the first plastic part body 210 and the pole is increased, resulting in a high cost. It is not recommended for use, and the product is defective.

[0089] In sample 17, the value of b is 1.5mm, the value of H is 2.0mm, and the value of b is greater than 0.5H, which does not meet the size limit of -1mm≤b≤0.5H. At this time, the depth of the groove 112 on the top wall 110 is large, the structural strength of the battery casing 100 is low, and the thrust test fails. It is not recommended for use and the product is defective.

[0090] Continue to see Figure 2 , Figure 6 and Fig. 9 In this embodiment, two electrode groups are provided in the battery housing 100. Figure 2 There are two first plastic parts 210, two connecting pieces 300 and two poles, and two first plastic parts 210 are respectively arranged along the top wall 110. Figure 2 At the two ends of the X-axis direction shown in the figure, the poles on the side of the two first plastic parts 210 away from the top wall 110 are respectively the positive pole and the negative pole. The two ends of the positive pole are connected to a connecting piece 300 and the positive pole ears of the two pole groups, and the two ends of the negative pole are connected to another connecting piece 300 and the negative pole ears of the two pole groups. Each first plastic part body 210 is provided with two through holes 201, and the two through holes 201 are respectively used for the positive pole ears of the two pole groups to pass through, or the two through holes 201 are respectively used for the negative pole ears of the two pole groups to pass through. The two through holes 201 on the first plastic part body 210 are along Figure 2 The Y-axis direction shown in FIG.

[0091] Furthermore, the second plastic body 220 is provided with a Figure 2 There are two through holes 201 at both ends of the X-axis direction shown in the figure, that is, there are four through holes 201 on the second plastic body 220, each through hole 201 is provided with a pole ear shaping structure 222 in the circumferential direction, and the through holes 201 correspond to the pole ear shaping structures 222 one by one. The positive pole ear of each pole group passes through a pole ear shaping structure 222, the through hole 201 and the first mounting hole 111 and is connected to the positive pole column. The negative pole ear of each pole group passes through the second plastic body 220 along Figure 2The tab shaping structure 222, through hole 201 and first mounting hole 111 at the other end of the X-axis direction shown in the figure are connected to the negative pole. Thus, the tabs of the two pole groups are led out of the battery housing 100, and are sequentially connected to the connecting piece 300 and the pole column on the outside of the battery housing 100, without occupying the internal space of the battery housing 100, with high space utilization and large volume energy of the pole group. It should be noted that each tab is provided with a tab shaping structure 222 to ensure that each tab has a good shape and is not prone to overlap short circuit.

[0092] Optionally, the support structure 223 in this embodiment is also provided with a plurality of support structures, wherein two support structures 223 are respectively arranged along the second plastic body 220. Figure 2 The two ends of the Y-axis direction shown in FIG. 2 are connected to the tab shaping structure 222 on one side thereof, and the remaining support structures 223 are arranged along the Figure 2 Between two adjacent tab shaping structures 222 in the Y-axis direction shown in FIG. , one or more support structures 223 may be provided between each two tab shaping structures 222. Here, one support structure 223 is provided between each two tab shaping structures 222 as an example for explanation. Figure 2 As shown in the figure, support structures 223 are provided on both sides of the Y-axis direction to provide support, thereby ensuring that the tab shaping structure 222 has high mechanical strength and is not easily deformed.

[0093] In some embodiments, the second plastic body 220 is located near the Figure 2 In the support structure 223 at the end of the Y-axis direction shown in the figure, one end of the connecting plate 2231 is connected to the tab shaping structure 222, and the other end of the connecting plate 2231 is connected to the supporting plate 2232, and the supporting plate 2232 is connected to the connecting plate 2231 near the second plastic body 220 along Figure 2 The edge in the Y-axis direction shown in the figure, the support plate 2232 is arranged on the end face of the connecting plate 2231 close to the top wall 110, and the support plate 2232 abuts against the top wall 110, thereby supporting the pole ear shaping structure 222 connected thereto. In the support structure 223 located between two adjacent pole ear shaping structures 222, the two ends of its connecting plate 2231 are respectively connected to the end of the guide plate 2221 of a pole ear shaping structure 222 close to the pole group, the support plate 2232 is connected to the middle part of the connecting plate 2231, and the support plate 2232 is arranged on the end face of the connecting plate 2231 close to the top wall 110, and the support plate 2232 abuts against the top wall 110, thereby supporting the two adjacent pole ear shaping structures 222.

[0094] Continue to see Figure 6 and Fig. 9A second flange 212 and a connecting rib 213 are provided on the side of the first plastic body 210 away from the pole group. The second flange 212 and the connecting rib 213 both extend in a direction away from the pole group. The second flange 212 is arranged in the circumference of the through hole 201. The connecting rib 213 is connected to the second flange 212. The second flange 212, the connecting rib 213 and the first plastic body 210 form a mounting groove 2131. At least a portion of the connecting sheet 300 is embedded in the mounting groove 2131. By way of example, in this embodiment, two through holes 201 are provided on the first plastic body 210, two second flanges 212 and two connecting ribs 213 are provided, and a second annular flange 212 is provided around each through hole 201, and both ends of each connecting rib 213 are respectively connected to a second flange 212, so that the second flange 212, the connecting rib 213 and the first plastic body 210 form a mounting groove 2131, and at least part of the connecting sheet 300 is embedded in the mounting groove 2131. Thus, the size of the battery housing assembly along the second direction is further reduced, so as to improve the space utilization and the energy density of the whole battery pack.

[0095] Continue to see Figure 2 and Figure 3 The battery housing assembly in this embodiment further includes an explosion-proof valve 400. A second mounting hole 113 is provided on the top wall 110, and the explosion-proof valve 400 is arranged in the second mounting hole 113; a vent hole 224 is provided on the second plastic body 220 at a position corresponding to the second mounting hole 113, Figure 2 , Figure 3 In the Z-axis direction shown in , the projection of the vent hole 224 on the top wall 110 coincides with the projection of the explosion-proof valve 400 on the top wall 110. Therefore, when the pressure in the battery housing 100 exceeds the valve opening pressure of the explosion-proof valve 400, high-temperature, high-pressure gas and liquid can be discharged from the battery housing 100 through the vent hole 224 and the explosion-proof valve 400, avoiding the risk of explosion and having high safety. In addition, criss-crossing support ribs 114 are also provided in the second mounting hole 113, and the support ribs 114 can support the battery housing 100 and improve the structural strength of the battery housing 100 where the second mounting hole 113 is opened. In addition, a plurality of vent holes 224 can be provided at intervals on the second plastic body 220 to increase the flow area, so that high-temperature, high-pressure gas and liquid can be discharged quickly and circulate smoothly.

[0096] Optionally, in some embodiments, the top wall 110 is further provided with a first injection hole 115, and the second plastic body 220 is provided with a second injection hole (not shown in the figure) at a position corresponding to the first injection hole 115. Figure 2 , Figure 3In the Z-axis direction shown in , the projection of the first injection hole 115 on the top wall 110 coincides with the projection of the second injection hole on the top wall 110. Electrolyte can be injected into the mounting cavity of the battery housing 100 through the first injection hole 115 and the second injection hole so that the electrode group can be immersed in the electrolyte. After the injection is completed, an injection plug can be installed in the first injection hole 115 and / or the second injection hole to seal the first injection hole 115 and / or the second injection hole to prevent leakage of the electrolyte. Exemplarily, the injection plug is made of a material with elastic deformation ability such as rubber.

[0097] This embodiment also provides a battery, including a bottom plate, a pole group, and the above-mentioned battery housing assembly, wherein the bottom plate is connected to the opening 121 of the battery housing 100 to encapsulate the pole group in the mounting cavity of the battery housing 100. The pole lug of the pole group can be led out through the battery housing assembly, and connected to the pole column through the connecting piece 300, and then the pole column is connected to the external circuit, so that the pole group can supply power to the external circuit or store energy.

[0098] In the battery housing assembly, the connecting piece 300 and the pole are both arranged outside the installation cavity of the battery housing 100, the space utilization rate inside the battery housing 100 is high, the volume of the pole group is increased, and the energy density of the battery is high. In addition, the connecting piece 300 and the pole are both flat, and the overall volume of the battery housing 100 is small, which is conducive to improving the space utilization rate of the battery in the whole pack of batteries, and the energy density is large. In addition, the pole ear shaping structure 222 on the second plastic body 220 can gather the pole ear into the through hole 201, and the overall shape of the pole ear is good, and it is not easy to short-circuit with the battery housing 100, and the battery is safe and reliable.

[0099] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery housing assembly, characterized in that: include: A battery housing, wherein the interior is hollow to form a mounting cavity, one side of the battery housing has an opening communicating with the mounting cavity, the electrode group is loaded into the mounting cavity through the opening, and a first mounting hole is provided on one wall of the battery housing; A combined plastic part, partly located outside the mounting cavity and attached to the end surface of the battery housing away from the electrode group, and partly located inside the mounting cavity and attached to the end surface of the battery housing close to the electrode group, wherein the combined plastic part is provided with a through hole; A connecting piece is located on a side of the combined plastic part away from the battery housing, the connecting piece is fixed to the combined plastic part by hot melting, and the pole lug of the pole group is connected to the connecting piece after passing through the first mounting hole and the through hole; The pole is located on a side of the connecting piece away from the battery housing, and the pole is connected to the connecting piece.

2. The battery housing assembly according to claim 1, characterized in that: The battery housing comprises a top wall and a peripheral side wall, the top wall and the peripheral side wall are arranged to form the mounting cavity, and the top wall is provided with the first mounting hole.

3. The battery housing assembly according to claim 2, characterized in that: The combined plastic part comprises a first plastic part body and a second plastic part body, the first plastic part body and the second plastic part body are both provided with the through hole, the first plastic part body is located outside the installation cavity and is attached to the end surface of the top wall away from the pole group, and the second plastic part body is located inside the installation cavity and is attached to the end surface of the top wall close to the pole group; And / or, one of the first plastic body and the second plastic body is provided with a first flange, the first flange is located in the circumference of the through hole, the first flange is penetrated into the first mounting hole and fits with the inner wall of the first mounting hole.

4. The battery housing assembly according to claim 3, characterized in that: A pole ear shaping structure is provided on one side of the second plastic component body close to the pole group, and the pole ear shaping structure includes two guide plates, the two guide plates are respectively arranged on both sides of the through hole, and the two guide plates are inclined in the direction away from the axis of the through hole, and along the direction away from the through hole, an open gradually widening bell mouth is formed between the two guide plates, the large end of the bell mouth faces the pole group, and the small end of the bell mouth is connected to the second plastic component body, and the pole ear is penetrated in the bell mouth.

5. The battery housing assembly according to claim 4, characterized in that: The angle between the guide plate and the axis of the through hole is α, and the value range of α is 45°≤α≤87°.

6. The battery housing assembly according to claim 4, characterized in that: A support structure is provided on one side of the second plastic body close to the top wall, the support structure includes a connecting plate and a support plate, the connecting plate is connected to the tab shaping structure, the support plate is arranged on the end surface of the connecting plate close to the top wall, and the support plate abuts against the top wall; Wherein, along the first direction, the distance between the end surface of the support plate facing away from the guide plate and the end of the guide plate close to the support plate is e, and the value range of e is 0.5mm≤e≤20mm; And / or, along the second direction, a distance between an end surface of the connecting plate facing away from the top wall and an end surface of the second plastic component body facing away from the top wall is f, and a value range of f is 0 mm ≤ f ≤ 5 mm.

7. The battery housing assembly according to claim 3, characterized in that: The first plastic body is provided with an overlapped portion in the circumferential direction, and a sink groove is provided on the end surface of the top wall facing away from the second plastic body, and the overlapped portion is embedded in the sink groove and fits with the bottom wall of the sink groove; Wherein, along the second direction, the thickness of the top wall is H, the distance between the end surface of the overlap portion away from the second plastic component body and the end surface of the top wall away from the second plastic component body is b, and the value range of b satisfies: -1mm≤b≤0.5H, 1mm≤H≤3mm; And / or, along the first direction and the third direction, the width of the overlapping portion is c, and the value range of c satisfies: 0mm≤c≤10mm.

8. The battery housing assembly according to claim 3, characterized in that: A second flange and a connecting rib are provided on the side of the first plastic component body away from the pole group. The second flange is arranged in the circumference of the through hole. The connecting rib is connected to the second flange. The second flange, the connecting rib and the first plastic component body form an installation groove. At least part of the connecting piece is embedded in the installation groove.

9. The battery housing assembly according to claim 1, characterized in that: One of the connecting piece and the combined plastic part is provided with a fusion column, and the other of the connecting piece and the combined plastic part is provided with a fixing hole, and the fusion column is fixed to the fixing hole by hot melting.

10. A battery, characterized in that: The invention comprises a bottom plate, a pole group, and a battery housing assembly according to any one of claims 1 to 9, wherein the bottom plate is connected to an opening of the battery housing, and the pole group is encapsulated in a mounting cavity of the battery housing.

Images