Battery arrangement and battery pack

Abstract

Battery assembly comprising: a battery cell (3) with a first outer surface (32) having a pressure relief device (31); a printed circuit board (1) arranged on a side of the battery cell (3) on which the pressure relief device (31) is provided and parallel to and at a distance from the first outer surface (32), wherein a projection of the printed circuit board (1) on the first outer surface (32) at least partially overlaps the pressure relief device (31) in a direction perpendicular to the first outer surface (32), wherein the printed circuit board (1) has a through section (11), and the through section (11) is designed to be closed under a normal pressure and to be opened under a preset pressure, wherein, along the direction perpendicular to the first outer surface (32), a distance between a surface of the pressure relief device (31) facing the circuit board (1) and a surface of the circuit board (1) facing the pressure relief device (31) is represented by d and a length of the passage section (11) is represented by L, satisfying: 15 mm 2 ≤d·L≤20000 mm 2 .

Description

FIELD OF TECHNOLOGY

[0001] The present disclosure relates to the field of battery technology, in particular to a battery assembly and a battery pack. STATE OF THE ART

[0002] Battery packs typically feature flexible printed circuit boards (FPCs) for sensing and monitoring information such as battery voltage and temperature. The battery pack is formed by stacking multiple battery cells, and due to the compact space inside the battery pack, the FPC sometimes covers the pressure relief device. However, if the pressure relief device ruptures, the FPC can obstruct the release of high-temperature fluid, impairing the pressure relief rate. SUMMARY

[0003] In view of this, the present disclosure provides a battery assembly and a battery pack to solve the problem that the FPC can easily affect the pressure relief rate.

[0004] In a first aspect, the present disclosure provides a battery assembly comprising: a battery cell having a first outer surface having a pressure relief device; a printed circuit board arranged on a side of the battery cell on which the pressure relief device is provided, and parallel to and spaced from the first outer surface, wherein a projection of the printed circuit board on the first outer surface at least partially overlaps the pressure relief device in a direction perpendicular to the first outer surface; wherein the printed circuit board has a passage portion, and the passage portion is designed to be closed under a normal pressure and opened under a preset pressure, wherein, along the direction perpendicular to the first outer surface, a distance between a surface of the pressure relief device facing the circuit board and a surface of the circuit board facing the pressure relief device is represented by d and a length of the passage portion is represented by L, satisfying: 15 mm 2 ≤d·L≤20000 mm 2 .

[0005] The disclosure has the following advantageous effects: the battery assembly provided by the embodiments of the present disclosure has a through portion formed in the circuit board, which is opened accordingly when the pressure relief device is in a bursting state and a preset pressure is reached, thereby preventing the circuit board from hindering the discharge of high-temperature medium when the pressure relief device bursts;and the range of d Lis is limited, that is, when the length L of the through section is longer, the corresponding opening length of the through section when the pressure relief device bursts is larger, resulting in a larger area of ​​the pressure relief channel and a larger pressure relief rate; and when the distance d is larger, the pressure relief space between the circuit board and the pressure relief device is more sufficient, so that the pressure relief device is less likely to be blocked, resulting in a larger pressure relief rate, and the through section can be broken more easily; therefore, when the distance d is large, the length L of the through section can be small, and when the distance d is small, the length L of the through section needs to be set larger to meet the pressure relief rate requirements.

[0006] In a second aspect, the present disclosure also provides a battery pack comprising: the battery assembly as described above.

[0007] Since the battery pack contains the battery assembly, it has the same effects as the battery assembly, which are not repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To more clearly illustrate the specific embodiments of the present disclosure or the technical solutions of the prior art, a brief introduction to the drawings used in describing the specific embodiments or the prior art is provided below. The drawings described below are obviously some embodiments of the present disclosure, and those skilled in the art can obtain other drawings based on these drawings without creative work. Fig. 1 is a plan view of a battery assembly of the present disclosure; Fig. 2 is a partial view showing a battery cell and a circuit board in a perspective state; Fig. 3 is a sectional view of the battery assembly of the present disclosure; Fig. 4 is a partial view of a first type of circuit board of the present disclosure; Fig. 5 is a partial view of a second type of circuit board of the present disclosure; Fig. 6 is a view showing a state in which the second type of circuit board and a battery cell are mounted; Fig. 7 is a partial view showing a battery cell with a first type of reinforcing rib and the circuit board in a perspective state; Fig. 8 is a partial view showing a battery cell with a second type of reinforcing rib and the circuit board in a perspective state; Fig. 9 is a view of a pressure relief device with the second type of reinforcing rib; Fig. 10 is a dimensional view of the pressure relief device with the second type of reinforcing rib; Fig. 11 is a view of a pressure relief device with a third type of reinforcing rib; Fig. 12 is a view of a pressure relief device with a fourth type of reinforcing rib; Fig. 13 is a view of a pressure relief device with a fifth type of reinforcing rib. Reference numbers:

[0009] 1 - printed circuit board; 2 - battery pack; 3 - battery cell; 4 - gas storage chamber; 11 - through section; 12 - gap section; 13 - overlap area; 101 - first printed circuit board body; 102 - second printed circuit board body; 31 - pressure relief device; 311 - reinforcing rib; 312 - notch portion; 3111 - first end point; 3112 - second end point; 3101 - first reinforcing rib segment; 3102 - second reinforcing rib segment; 3103 - third reinforcing rib segment; 32 - first outer surface. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0010] To clarify the purpose, technical solutions, and advantages of the embodiments of the present disclosure, the technical solutions in the embodiments of the present disclosure are described clearly and completely in conjunction with the accompanying drawings. Of course, the described embodiments are only a part of the embodiments of the present disclosure and not all of them. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present disclosure.

[0011] In describing the present disclosure, it should be noted that terms such as "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate orientation or positional relationships, are based on those shown in the drawings, are used only to conveniently describe the present disclosure and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation. Therefore, they should not be considered limitations of the present disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood as indicating or implying a relative meaning.

[0012] In describing the present disclosure, it should be noted that the terms "integrated," "connected," and "coupled" are to be understood broadly unless expressly stated and limited otherwise. For example, they may mean a fixed connection, a detachable connection, or an integral connection; a mechanical connection or electrical connection; a direct connection or indirect connection through intermediate media; or an internal connection between two elements. Those skilled in the art can understand the specific meanings of these terms in the present disclosure according to the respective situations.

[0013] Furthermore, the technical features involved in the various embodiments of the present disclosure described below may be combined with each other as long as they do not contradict each other.

[0014] The embodiments of the present disclosure are described below in connection with Fig. 1 to 13 described.

[0015] According to one embodiment of the present disclosure, a battery arrangement is provided, comprising: a battery cell (3) with a first outer surface (32) having a pressure relief device (31); a printed circuit board (1) on one side of the battery cell (3), on which the pressure relief device (31) is provided, and parallel to and at a distance from the first outer surface (32), wherein a projection of the printed circuit board (1) on the first outer surface (32) at least partially overlaps the pressure relief device (31) in a direction perpendicular to the first outer surface (32); wherein the printed circuit board (1) has a through-portion (11), wherein the through-portion (11) is designed to be closed under a normal pressure and to be opened under a preset pressure, wherein, along the direction perpendicular to the first outer surface (32), a distance between a surface of the pressure relief device (31) facing the circuit board (1) and a surface of the circuit board (1) facing the pressure relief device (31) is represented by d and a length of the passage section (11) is represented by L, satisfying: 15 mm 2 ≤d·L≤20000 mm 2 .

[0016] The first outer surface (32) of the battery cell (3), which has the pressure relief device (31), can in particular be an outer surface of a shell of the battery cell (3) or an outer surface of a cover plate.

[0017] The printed circuit board (1) is arranged parallel to and at a distance from the first outer surface (32). As shown in Fig. 3, in particular, a support structure can be arranged around the pressure relief device (31) to create a gap between the circuit board (1) and the first outer surface (32). In this embodiment, the support structure can be arranged around the circumference of the pressure relief device (31), thereby forming a gas storage chamber (4) enclosed by the circuit board (1), the pressure relief device (31), and the support structure, thereby preventing the circuit board (1) from directly adhering to the pressure relief device (31) and impairing the bursting of the pressure relief device (31), thus ensuring a smooth bursting of the pressure relief device (31).

[0018] A through-portion (11) formed in the printed circuit board (1) can have various specific shapes, which are described in detail below. The through-portion (11) is normally closed, meaning that the printed circuit board (1) is sealed at the position of the through-portion (11), preventing foreign matter such as condensation or metal contaminants from falling onto the pressure relief device and causing corrosion or short circuits.The passage section (11) is opened accordingly when the pressure relief device (31) bursts, which means that when the pressure relief device (31) bursts, high-temperature medium is released from the interior of the battery cell (3) and the quickly released high-temperature medium breaks through the passage section (11) of the circuit board (1), whereby the passage section (11) is brought into an open state and the pressure relief is thereby facilitated.

[0019] Along the direction perpendicular to the first outer surface (32), the distance between the surface of the pressure relief device (31) facing the circuit board (1) and the surface of the circuit board (1) facing the pressure relief device (31) is represented by d, and in this embodiment, d may represent the height of the gas storage chamber (4).

[0020] Since the structure of the passage portion (11) can have a variety of shapes, the passage portion (11) can be arranged as a single continuous portion, or a plurality of individual passage portions (11) can be spaced apart from each other. Note that in this embodiment, the length L of the passage portion (11) refers to the length of the passage portion (11) arranged as the single continuous portion. The range of the length L of the passage portion (11) can be 15 mm≤L≤2000 mm. When a plurality of individual passage portions (11) are spaced apart from each other, the length L of the individual passage portion (11) is slightly smaller. For example, the range of the length L of the individual passage portion (11) can be 15 mm≤L≤50 mm.If the passage section (11) is arranged as a single continuous section, the length of the passage section (11) may be slightly longer, with a maximum value of 2000 mm.

[0021] In this embodiment, the range of the distance d may be 1 mm≤d≤10 mm.

[0022] In the battery assembly provided by the embodiment of the present disclosure, a through portion (11) is formed in the circuit board (1), and the through portion (11) is opened accordingly when the pressure relief device (31) is in a bursting state, thereby preventing the circuit board (1) from hindering the discharge of high-temperature medium when the pressure relief device bursts. The range of d·L may be restricted. When the length L of the through portion is longer, the length of the opening corresponding to the through portion is longer when the pressure relief device (31) bursts, resulting in a larger area of ​​a pressure relief channel and a larger pressure relief rate.When the distance d is larger, the pressure relief space between the circuit board (1) and the pressure relief device (31) is more sufficient, so the pressure relief device (31) is less likely to be blocked, resulting in a higher pressure relief rate, and thus the through section can be opened more easily. Therefore, when the distance d is relatively large, the length L of the through section (11) can be relatively small. When the distance d is relatively small, the length L of the through section (11) must be set larger to meet the pressure relief rate requirements.

[0023] In some embodiments, as used in connection with Fig. 4, the printed circuit board (1) comprises a first printed circuit board body (101) and a second printed circuit board body (102). The first printed circuit board body (101) and the second printed circuit board body (102) partially overlap to form an overlap region (13), and the through-section (11) is formed at a junction where the first printed circuit board body (101) and the second printed circuit board body (102) overlap each other; satisfying: 75 mm 2 ≤d·L≤20000 mm 2 ; and satisfying: 5 mm≤d≤10 mm.

[0024] In this embodiment, the printed circuit board (1) consists of two parts. The overlap region (13) is formed by the overlap of the first printed circuit board body (101) and the second printed circuit board body (102), wherein the through section (11) is formed at the junction where the first printed circuit board body (101) and the second printed circuit board body (102) overlap each other. In a normal use state, the first printed circuit board body (101) and the second printed circuit board body (102) overlap at the overlap region (13) to keep the through section (11) closed, while in the bursting state of the pressure relief device, the first printed circuit board body (101) and the second printed circuit board body (102) are separated at the overlap region (13) to open the through section (11).The overlap area (13) is relatively difficult to penetrate by high-temperature media, so sufficient pressure relief space is required, which means that the distance d must be correspondingly larger. However, the distance d is not too large, because an excessive distance would result in insufficient pressure, making the overlap area (13) more difficult to penetrate. Therefore, the value of the distance d can be closer to the upper limit of the range.

[0025] In some embodiments, the circuit board (1) comprises a first circuit board body (101) and a second circuit board body (102). An edge of the first circuit board body (101) on one side thereof abuts an edge of the second circuit board body (102) on one side thereof, and the through-portion (11) is formed at a junction where the first circuit board body (101) abuts the second circuit board body (102).

[0026] In some embodiments, the through-section (11) is formed by making at least a portion of the surface of the printed circuit board (1) thinner, satisfying: 15 mm 2 ≤d·L≤20000 mm 2 , and satisfying: 1 mm≤d≤5 mm.

[0027] In this embodiment, the through portion (11) is a scratch-shaped structure formed by locally thinning the printed circuit board (1), eliminating the need for the printed circuit board (1) to be composed of two parts. Consequently, the two parts do not need to overlap. Therefore, the through portion (11) can be more easily penetrated and opened. In this case, the distance d can be relatively small and L can be relatively large, but L cannot be too large to avoid the scratch-shaped structure being too long, thereby preventing the scratch-shaped structure from being opened due to vibration in a normal state.

[0028] In some embodiments, as used in connection with Fig. 4, the through section (11) is a single continuous section on the circuit board (1).

[0029] In this embodiment, the single through-portion (11) can be formed either by using the two-part printed circuit board (1) or by locally thinning the surface of the printed circuit board (1).

[0030] A single through section (11) facilitates manufacturing and improves assembly efficiency because it is not necessary to align multiple individual through sections (11) during assembly.

[0031] In some embodiments, as used in connection with Fig. 5, the passage section (11) comprises a plurality of individual passage sections (11) extending along the same direction, with gap sections (12) being formed between adjacent individual passage sections (11).

[0032] By forming gap portions (12) between adjacent individual through portions (11), the thickness of the gap portions (12) can be equal to the thickness of a portion of the circuit board (1) other than the through portions (11), and the overall strength of the circuit board (1) is improved.

[0033] In some embodiments, as used in connection with Fig. 6, the battery arrangement comprises a battery column (2) formed by stacking a plurality of battery cells (3) along a first direction.

[0034] The extension direction of the passage section (11) is parallel to the first direction.

[0035] The single passage section (11) corresponds to pressure relief devices (31) of at least two battery cells (3); and in this case, the length of the single passage section (11) is represented by L2, satisfying: 30 mm 2 ≤d·L2≤600 mm 2 .

[0036] In this embodiment, the single passage section (11) corresponds to pressure relief devices (31) of at least two battery cells (3), thereby ensuring the length of the single passage section (11) and guaranteeing the pressure relief space and pressure relief rate. Since the length of the single passage section (11) is relatively long, the corresponding distance d can be reduced accordingly.

[0037] It should be noted that the length L of the passage section (11) overlaps the length L2 of the individual passage section (11).

[0038] In other embodiments, the battery assembly comprises the battery column (2) formed by stacking a plurality of battery cells (3) along a first direction; the extension direction of the passage section (11) is parallel to the first direction; the individual passage section (11) corresponds to the pressure relief device (31) of a battery cell (3); the length of the individual passage section (11) is represented by L2, satisfying: 15 mm 2 ≤d·L2≤300 mm 2 .

[0039] In this embodiment, the single passage section (11) corresponds to only the pressure relief device (31) of one battery cell (3); rupture of the pressure relief device of one battery cell (3) does not cause rupture of the passage sections (11) corresponding to other battery cells (3), thereby minimizing the impact on other batteries. In this case, the length L2 of the single passage section (11) is relatively small, and the corresponding distance d must be increased accordingly.

[0040] In some embodiments, the battery assembly comprises the battery column (2) formed by stacking a plurality of battery cells (3) along the first direction; the extension direction of the passage section (11) is parallel to the first direction; the length of the single passage section (11) is represented by L2, the length of the battery stack (2) is represented by E, satisfying: 0.024≤L2 / E≤0.05.

[0041] The length E of the battery pack (2) is relatively fixed. In this case, if the length L2 of the single passage section (11) is too long, the passage section (11) may open due to vibration or other reasons under normal conditions. If the length L2 of the single passage section (11) is too short, this would not be conducive to normal pressure relief in the case of high-temperature media.

[0042] In some embodiments, as used in connection with Fig. 7, the pressure relief device (31) has a notch portion (312) near its outer peripheral edge in a direction parallel to the first outer surface (32), and a reinforcing rib (311) is provided on a side of the notch portion (312) remote from the outer peripheral edge.

[0043] In a direction perpendicular to the first outer surface (32), a projection of the passage portion (11) on the first outer surface (32) at least partially overlaps the reinforcing rib (311), satisfying: 20 mm 2 ≤d·L≤150 mm 2 ; and satisfying: 1 mm≤d≤5 mm.

[0044] The reinforcing rib (311) is provided on the pressure relief device (31) to stabilize the bursting pressure and ensure that the pressure relief device (31) does not deform before bursting. Upon bursting of the pressure relief device (31), the portion of the pressure relief device (31) located on either side of an axis along which the reinforcing ribs (311) extend warps and deforms in an ejection direction of the high-temperature medium along with the ejection of the high-temperature medium. The portion of the pressure relief device (31) on which the reinforcing rib is provided typically maintains high strength without deformation, and the pressure relief channel is the opened portion after the pressure relief device (31) warps and deforms.Therefore, when the projection of the through portion (11) on the first outer surface (32) at least partially overlaps with the reinforcing rib (311), the portion of the pressure relief device (31) at the reinforcing rib (311) is difficult to deform and form a pressure relief channel, making the corresponding area of ​​the through portion (11) difficult to penetrate. Therefore, the through portion (11) must be made longer to increase the pressure relief area and meet the pressure relief rate requirements.

[0045] In other embodiments, as described in connection with Fig. 8, the pressure relief device (31) has a notch portion (312) near its outer peripheral edge in a direction parallel to the first outer surface (32), and a reinforcing rib (311) is provided on a side of the notch portion (312) remote from the outer peripheral edge.

[0046] In a direction perpendicular to the first outer surface (32), a projection of the passage portion (11) on the first outer surface (32) does not overlap with the reinforcing rib (311), satisfying: 75 mm 2 ≤d·L≤200 mm 2 ; and satisfying: 5 mm≤d≤10 mm.

[0047] Since the projection of the through portion (11) on the first outer surface (32) does not overlap with the reinforcing rib (311), the through portion (11) directly faces the bent and deformed pressure relief channel, thereby causing the through portion (11) to be easily broken, so that accordingly the length of the corresponding through portion (11) can be set appropriately smaller.

[0048] In some embodiments, as used in connection with Fig. 8 and Fig. 9, the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), including a first end point (3111) and a second end point (3112) at both ends of the line segment; the extending direction of the reinforcing rib (311) is defined as the direction of the line connecting the first end point (3111) and the second end point (3112).

[0049] The extension direction of the reinforcing rib (311) is parallel to the extension direction of the passage section (11), fulfilling: 20 mm 2 ≤d·L≤150 mm 2 .

[0050] Since the extension direction of the reinforcing rib (311) is parallel to that of the through-portion (11), the probability of deformation of the reinforcing rib (311) along the extension direction of the reinforcing rib (311) is low, making it difficult to provide pressure relief space. This means that the pressure relief space created by warping on both sides of the extension direction of the reinforcing rib does not directly face the through-portion (11), so the through-portion (11) must be longer to avoid affecting the pressure relief rate.

[0051] In other embodiments, as described in connection with Fig. 7, the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), including a first end point (3111) and a second end point (3112) at both ends of the line segment; the extending direction of the reinforcing rib (311) is defined as the direction of the line connecting the first end point (3111) and the second end point (3112).

[0052] The extension direction of the reinforcing rib (311) is perpendicular to the extension direction of the passage section (11), fulfilling: 75 mm 2 ≤d·L≤200 mm 2 .

[0053] Since the extension direction of the reinforcing rib (311) is perpendicular to that of the passage portion (11), the pressure relief space created by warping on both sides of the extension direction of the reinforcing rib directly faces the passage portion (11), so that the passage portion (11) can be easily opened, whereby the passage portion (11) can be smaller.

[0054] In some embodiments, as used in connection with Fig. 10, the length s of the reinforcing rib (311) is defined as the straight line distance between the first end point (3111) and the second end point (3112).

[0055] Along the extending direction of the reinforcing rib (311), the distance between the two side edges of the notch portion (312) is represented by t, satisfying: s / t≥0.2, and satisfying: 15 mm≤L≤20 mm.

[0056] The ratio s / t represents the proportion of the length of the reinforcing rib (311) with respect to the entire area of ​​the pressure relief device (31). When the length s of the reinforcing rib (311) is longer, bursting of the pressure relief device (31) occurs more safely and controllably, so that high-temperature medium can quickly break through the passage section, and thus the corresponding length L of the passage section (11) does not need to be so long.

[0057] In some embodiments, the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), and the line segment is an arc line.

[0058] When the structure having the shape of the line segment serves as a reinforcing rib, an arc line provides greater strength than a straight line, thereby better maintaining the overall strength of the pressure relief device (31) and making the bursting of the pressure relief device (31) safer and more controllable.

[0059] As a modification, the line segment of the reinforcing rib (311) can also be straight.

[0060] In some embodiments, as used in connection with Fig. 11 and Fig. 12, the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31) and includes a first reinforcing rib segment (3101) and a second reinforcing rib segment (3102) which intersect each other.

[0061] By having the reinforcing rib (311) having the first reinforcing rib segment (3101) and the second reinforcing rib segment (3102) intersecting each other, the reinforcing effect is better, making the entire pressure relief device (31) more stable and controllable.

[0062] In other embodiments, as described in connection with Fig. 10, the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), comprising a first reinforcing rib segment (3101) and a second reinforcing rib segment (3102) which do not intersect each other, with a minimum distance f between them, which is 0.1 mm≤f≤5 mm, and satisfying: 15 mm≤L≤20 mm.

[0063] If the reinforcement rib (311) includes the first reinforcement rib segment (3101) and the second reinforcement rib segment (3102) that do not intersect, if the distance between the first and second reinforcement rib segments is too large, this would result in bulging deformation of the pressure relief device (31) at the distance, making the entire pressure relief device (31) unstable. Therefore, the minimum distance between the first and second reinforcement rib segments must be controlled, and if the distance f satisfies 0.1 mm≤f≤5 mm, the length L of the through portion (11) can be appropriately reduced.

[0064] In some embodiments, as used in connection with Fig. 13, the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31) and includes a first reinforcing rib segment (3101), a second reinforcing rib segment (3102) and a third reinforcing rib segment (3103).

[0065] By providing more reinforcing rib segments, the reinforcing effect can be further improved, so that the entire pressure relief device (31) becomes more stable and controllable.

[0066] In some embodiments, as used in connection with Fig. 12, the reinforcing rib (311) is connected to at least a portion of the notch portion (312); and satisfies: 20 mm≤L≤30 mm.

[0067] When the reinforcing rib (311) is connected to at least a portion of the notched portion (312), they may be formed in the same manner, for example, both may be pressed as depressions onto the pressure relief device (31), except that the notched portion (312) with less remaining thickness is thinned more; while the reinforcing rib (311) at the position of the line segment is only slightly thinned.

[0068] The impression of indentations on the pressure relief device (31) increases its overall three-dimensional thickness and therefore provides a reinforcing effect. When the reinforcing rib (311) and the notched portion (312) intersect, stress can easily concentrate at the intersection point, causing premature rupture of the pressure relief device (31). Since the pressure relief device (31) ruptures prematurely before reaching the preset rupture pressure, rupture of the passage portion (11) by high-temperature medium at low pressure becomes difficult, so the length of the passage portion (11) must be increased to reduce its opening difficulty.

[0069] In some embodiments, as used in connection with Fig. 10 and Fig.11, the reinforcing rib (311) has no contact with the notch portion (312) and the minimum distance j between them satisfies 0.1 mm≤j≤2 mm, and satisfies: 15 mm≤L≤20 mm.

[0070] When the reinforcing rib (311) does not contact the notch portion (312), the remaining thickness of the pressure relief device, except for the notch, is uniform, so that the burst pressure of the pressure relief device (31) becomes more stable and controllable as a whole. If the minimum distance between the reinforcing rib and the notch portion is too large, this indicates that the reinforcing rib (311) is too small as a whole, providing insufficient reinforcement. If the minimum distance is too small, this indicates that the overall size of the reinforcing rib (311) is sufficient, so that the pressure relief device (31) is more stable and controllable and can burst normally under the burst pressure, in which case the through portion (11) can be set relatively small.

[0071] According to embodiments of the present disclosure, in another aspect, there is further provided a battery pack comprising: the battery assembly as described above.

[0072] Obviously, the above embodiments are merely illustrative examples and are not limitations on the implementation modes. Although the embodiments of the present disclosure have been described in conjunction with the drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations are all within the scope defined by the present disclosure.

Claims

[1] Battery assembly comprising: a battery cell (3) with a first outer surface (32) having a pressure relief device (31); a printed circuit board (1) arranged on a side of the battery cell (3) on which the pressure relief device (31) is provided and parallel to and at a distance from the first outer surface (32), wherein a projection of the printed circuit board (1) on the first outer surface (32) at least partially overlaps the pressure relief device (31) in a direction perpendicular to the first outer surface (32), wherein the printed circuit board (1) has a through section (11), and the through section (11) is designed to be closed under a normal pressure and to be opened under a preset pressure, wherein, along the direction perpendicular to the first outer surface (32), a distance between a surface of the pressure relief device (31) facing the circuit board (1) and a surface of the circuit board (1) facing the pressure relief device (31) is represented by d and a length of the passage section (11) is represented by L, satisfying: 15 mm 2 ≤d·L≤20000 mm 2 . [2] Battery assembly according to claim 1, wherein the printed circuit board (1) comprises a first printed circuit board body (101) and a second printed circuit board body (102), wherein the first printed circuit board body (101) and the second printed circuit board body (102) at least partially overlap to form an overlap region (13), and the through section (11) is formed at a junction where the first printed circuit board body (101) and the second printed circuit board body (102) overlap each other; satisfying: 75 mm 2≤d·L≤20000 mm 2 ; and satisfying: 5 mm≤d≤10 mm. [3] The battery assembly according to claim 1, wherein the circuit board (1) comprises a first circuit board body (101) and a second circuit board body (102), an edge of the first circuit board body (101) on one side thereof abuts an edge of the second circuit board body (102) on one side thereof, and the through portion (11) is formed at a junction where the first circuit board body (101) abuts the second circuit board body (102). [4] Battery assembly according to claim 1, wherein the through portion (11) is formed by making at least a portion of a surface of the circuit board (1) thinner, satisfying: 15 mm 2 ≤d·L≤20000 mm 2 ; and satisfying: 1 mm≤d≤5 mm. [5] The battery assembly according to claim 1, wherein the through-portion (11) is a single continuous portion on the circuit board (1). [6] The battery assembly according to claim 1, wherein the passage portion (11) comprises a plurality of individual passage portions extending along a same direction, and a gap portion (12) is formed between adjacent individual passage portions (11). [7] A battery assembly according to claim 6, wherein the battery assembly comprises a battery column (2), the battery column (2) being formed by stacking a plurality of the battery cells (3) along a first direction; an extension direction of the passage section (11) is parallel to the first direction; and the single passage section (11) corresponds to the pressure relief devices (31) of at least two of the plurality of battery cells (3); and a length of the single passage section (11) is represented by L2, satisfying: 30 mm 2 ≤d·L2≤600 mm 2 . [8] A battery assembly according to claim 6, wherein the battery assembly comprises a battery column (2), the battery column (2) being formed by stacking a plurality of the battery cells (3) along a first direction; and an extension direction of the passage portion (11) is parallel to the first direction; the single passage portion (11) corresponds to the pressure relief device (31) of one of the plurality of battery cells (3); and a length of the single passage portion (11) is represented by L2, satisfying: 15 mm 2 ≤d·L2≤300 mm 2 . [9] A battery assembly according to claim 6, wherein the battery assembly comprises a battery column (2), the battery column (2) being formed by stacking a plurality of battery cells (3) along a first direction; an extension direction of the passage section (11) is parallel to the first direction; and a length of the single passage section (11) is represented by L2 and a length of the battery pack (2) is represented by E, satisfying: 0.024≤L2 / E≤0.

05. [10] The battery assembly according to claim 6, wherein the pressure relief device (31) has, in a direction parallel to the first outer surface (32), a notch portion (312) near an outer peripheral edge of the pressure relief device (31), and a reinforcing rib (311) is provided on a side of the notch portion (312) remote from the outer peripheral edge; and in the direction perpendicular to the first outer surface (32), a projection of the through portion (11) on the first outer surface (32) at least partially overlaps the reinforcing rib (311), satisfying: 20 mm 2 ≤d·L≤150 mm 2 ; and satisfying: 1 mm≤d≤5 mm. [11] The battery assembly according to claim 6, wherein the pressure relief device (31) has a notch portion (312) near an outer peripheral edge in a direction parallel to the first outer surface (32), and a reinforcing rib (311) is provided on a side of the notch portion (312) remote from the outer peripheral edge; and in the direction perpendicular to the first outer surface (32), a projection of the through portion (11) on the first outer surface (32) does not overlap with the reinforcing rib (311); satisfying: 75 mm 2 ≤d·L≤200 mm 2 ; and satisfying: 5 mm≤d≤10 mm. [12] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), the reinforcing rib (311) has a first end point (3111) and a second end point (3112) at two ends of the line segment; an extending direction of the reinforcing rib (311) is defined as a direction of a line connecting the first end point (3111) and the second end point (3112); and the extending direction of the reinforcing rib (311) is parallel to an extending direction of the through portion (11), satisfying: 20 mm 2 ≤d·L≤150 mm 2 . [13] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), the reinforcing rib (311) has a first end point (3111) and a second end point (3112) at two ends of the line segment; an extending direction of the reinforcing rib (311) is defined as a direction of a line connecting the first end point (3111) and the second end point (3112); and the extending direction of the reinforcing rib (311) is perpendicular to an extending direction of the through portion (11), satisfying: 75 mm 2 ≤d·L≤200 mm 2 . [14] The battery assembly according to claim 13, wherein a length of the reinforcing rib (311) is represented by s and is defined as a straight-line distance between the first end point (3111) and the second end point (3112); and along the extending direction of the reinforcing rib (311), a distance between two side edges of the notch portion (312) is represented by t, satisfying: s / t≥0.2, and satisfying: 15 mm≤L≤20 mm. [15] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), and the line segment is an arc line. [16] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), and the reinforcing rib (311) comprises a first reinforcing rib segment (3101) and a second reinforcing rib segment (3102) which intersect each other. [17] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), the reinforcing rib (311) comprising a first reinforcing rib segment (3101) and a second reinforcing rib segment (3102) that do not intersect each other, wherein a minimum distance between the first reinforcing rib segment (3101) and the second reinforcing rib segment (3102) is represented by f, satisfying 0.1 mm≤f≤5 mm, and satisfying: 15 mm≤L≤20 mm. [18] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) has a shape of a line segment formed on the pressure relief device (31), and the reinforcing rib (311) comprises a first reinforcing rib segment (3101), a second reinforcing rib segment (3102), and a third reinforcing rib segment (3103). [19] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) is connected to at least a portion of the notch portion (312); and satisfies: 20 mm≤L≤30 mm. [20] The battery assembly according to claim 10 or 11, wherein the reinforcing rib (311) does not contact the notch portion (312), and a minimum distance between the reinforcing rib (311) and the notch portion (312) is represented by j, satisfying 0.1 mm≤j≤2 mm, and satisfying: 15 mm≤L≤20 mm. [21] A battery pack comprising the battery assembly according to any one of claims 1 to 20.

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