Battery, battery pack and energy storage system

Abstract

The utility model provides a battery, a battery pack and an energy storage system, and belongs to the technical field of batteries. The battery comprises a battery cell, a battery shell and a battery cover plate, the battery cover plate comprises a conductive cover plate, an insulating base plate, a negative pole column unit and a positive pole column unit, and the negative pole column unit is electrically insulated from the conductive cover plate; the conductive cover plate is electrically connected with the battery shell, and the negative and positive column units are electrically connected with the negative and positive tabs of the battery cell respectively. The positive pole unit comprises a positive pole and a safety protection piece; the positive pole comprises a pole body part and a bottom plate part; the safety protection piece is electrically connected with the bottom plate part and the surface, facing the bottom plate part, of the conductive cover plate, and is fused when the current flowing through the safety protection piece exceeds a threshold value. Under the normal working condition of the battery, the potential of the battery shell is consistent with that of the positive pole, and the negative short corrosion risk of the battery is effectively reduced. When the battery is abnormally short-circuited, the safety protection piece is fused to cut off the short-circuit loop, so that the safety of the battery is improved. And the safety protection piece is convenient and efficient to assemble, and the sealing effect of the battery cover plate is not influenced.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the technical field of batteries, and particularly to batteries, battery packs, and energy storage systems. Background Art

[0002] A lithium-ion battery includes a battery cell, a battery housing, and a battery cover plate. The battery cover plate is welded to the battery housing to form a sealed cavity, and the battery cell is accommodated in the sealed cavity.

[0003] In the related art, the battery cover plate includes a conductive cover plate, an insulating backing plate, a positive terminal unit, and a negative terminal unit. The positive terminal unit and the negative terminal unit are assembled on the stacked conductive cover plate and insulating backing plate. There is an insulating spacer between the negative terminal in the negative terminal unit and the conductive cover plate to insulate the negative terminal from the conductive cover plate. A weak conductive spacer with weak conductivity is provided between the positive terminal in the positive terminal unit and the conductive cover plate. The weak conductive spacer is prepared by doping a conductive substance in an insulating material such as Polyphenylene Sulfide (PPS). It can reduce the corrosion risk of the battery. However, the resistance value of the weak conductive spacer decreases, resulting in a risk of short-circuit failure of the battery. Summary of the Utility Model

[0004] The embodiments of the present disclosure provide a battery cover plate and a battery, which can solve the technical problems existing in the related art.

[0005] On the one hand, a battery is provided. The battery includes: a battery cell; a battery housing that houses the battery cell; a battery cover plate, including a conductive cover plate, an insulating backing plate, a negative terminal unit, and a positive terminal unit. The negative terminal unit and the positive terminal unit respectively penetrate through the stacked conductive cover plate and insulating backing plate, and the negative terminal unit is electrically insulated from the conductive cover plate. The conductive cover plate is connected to the battery housing and electrically conductive. The negative terminal unit and the positive terminal unit are respectively electrically connected to the negative tab and the positive tab of the battery cell. The positive terminal unit includes a positive terminal and a safety protection member. The positive terminal includes a column body portion and a bottom plate portion surrounding the outer side of one end of the column body portion. The safety protection member is electrically connected to the bottom plate portion and the surface of the conductive cover plate facing the bottom plate portion, and the safety protection member is configured to melt when the current flowing through the safety protection member exceeds a threshold value.

[0006] The battery provided by the embodiments of the present disclosure is provided with a safety protection component in the positive electrode column unit, so that the positive electrode column is electrically connected to the conductive cover plate and the battery case, thereby increasing the potential of the battery case, eliminating the potential difference between the positive electrode column and the battery case, effectively avoiding the lithium insertion corrosion of the battery case, and reducing the negative short - circuit risk of the battery during normal operation. When the battery undergoes an abnormal short - circuit (for example, the negative electrode of the battery is electrically connected to the battery case or the conductive cover plate), a large current flows through the positive electrode column. The safety protection component can be fused when the current exceeds the threshold value, so that the connection between the positive electrode column and the conductive cover plate and the battery case is disconnected, thereby cutting off the short - circuit current loop and avoiding the short - circuit risk of the battery.

[0007] In summary, for the battery provided by the embodiments of the present disclosure, under normal operating conditions of the battery, the battery cover plate makes the potential of the battery case consistent with the potential of the positive electrode column, thereby effectively reducing the risk of negative short - circuit corrosion of the battery. In the case of an abnormal short - circuit in the battery, the safety protection component is fused to cut off the short - circuit loop, improving the safety of the battery and reducing risks such as battery fire and explosion. In addition, the safety protection component is located between the conductive cover plate and the bottom plate part of the positive electrode column. This assembly position not only makes the assembly of the safety protection component more convenient and efficient, but also does not affect the sealing assembly effect between the positive electrode column and the conductive cover plate.

[0008] In some possible implementation manners, the safety protection component includes a first part and a second part connected to each other; the first part is electrically connected to the bottom plate part, the second part is electrically connected to the surface of the conductive cover plate facing the bottom plate part, and the second part is used for fusing when the current exceeds the threshold value.

[0009] By making the safety protection component include a first part and a second part connected to each other, and by making the second part be set to be able to be fused when the current exceeds the threshold value, the size of the second part is bound to be smaller to provide a current fusing structure. The smaller - sized second part is located above the larger - sized first part, and the first part plays a supporting role for the second part. In this way, the second part is more easily and stably assembled between the first part and the conductive cover plate without being easily deformed, thereby ensuring the use stability of the safety protection component.

[0010] In some possible implementation manners, the positive electrode column unit further includes: a sealing ring sleeved outside the column body part, the outer side of the sealing ring has an annular step, and the annular step is clamped between the conductive cover plate and the bottom plate part; the number of the first parts is single, and the first part is a ring - shaped structure and is sleeved outside the annular step.

[0011] This implementation scheme not only helps to simplify the assembly difficulty of the safety protection component and improve the assembly efficiency, but also helps to improve the electrical conduction reliability between the first part and the bottom plate part. Moreover, the ring - shaped safety protection component sleeved outside the annular step of the sealing ring does not affect the sealing performance of the battery cover plate.

[0012] Based on the above implementation, the number of the second parts is multiple, and along the circumferential direction of the first part, the multiple second parts are spaced apart and distributed on the surface of the first part facing the conductive cover plate.

[0013] In some possible implementation manners, the number of the first parts is multiple, and the multiple first parts are sequentially distributed along the circumferential direction of the bottom plate part;

[0014] At least one of the second parts is connected to the surface of each first part facing the conductive cover plate.

[0015] Based on the above implementation, the positive electrode column unit further includes: a sealing ring sleeved outside the column body part, the outer side of the sealing ring has an annular step, and the annular step is clamped between the conductive cover plate and the bottom plate part; the first part has an arc-shaped cavity, and the first part is sleeved outside the annular step through the arc-shaped cavity.

[0016] In some possible implementation manners, the second part is at least one of a convex block shape, a needle shape, a sheet shape, and a filament shape. The second parts of the above various shapes can all easily provide a current fusing structure.

[0017] In some possible implementation manners, the second part is in a convex block shape, and the end of the second part facing away from the first part abuts against the conductive cover plate. The convex block-shaped second part realizes electrical conduction with the conductive cover plate through an abutting manner, which is beneficial to simplifying the assembly of the safety protection part in the battery cover plate and improving the assembly efficiency.

[0018] In some possible implementation manners, the positive electrode column unit further includes: a sealing ring sleeved outside the column body part, the outer side of the sealing ring has an annular step, and the annular step is clamped between the conductive cover plate and the bottom plate part;

[0019] The end of the second part facing away from the first part is higher than or flush with the end of the annular step on the same side.

[0020] By making the axial height of the convex block-shaped second part equal to or slightly higher than the height of the annular step, it is ensured that the second part can stably contact the conductive cover plate to enhance the contact stability between the two.

[0021] On the other hand, a battery pack is provided, and the battery pack includes a plurality of any one of the above-mentioned batteries, and the plurality of batteries are connected in series or in parallel.

[0022] On yet another hand, an energy storage system is provided, and the energy storage system includes a power converter and at least one battery pack as described above;

[0023] The power converter is used to perform power conversion on the voltage output by the battery pack and output it to the power grid or load, and / or perform power conversion on the voltage output by an external power supply and output it to the battery pack. Description of the Drawings

[0024] Figure 1 A combined view of an exemplary battery provided by an embodiment of the present disclosure;

[0025] Figure 2 An exploded view of an exemplary battery provided by an embodiment of the present disclosure;

[0026] Figure 3 A combined view of an exemplary battery cover plate provided by an embodiment of the present disclosure;

[0027] Figure 4 An exploded view of an exemplary battery cover plate provided by an embodiment of the present disclosure;

[0028] Figure 5 A cross-sectional view of an exemplary battery cover plate provided by an embodiment of the present disclosure;

[0029] Figure 6 Based on Figure 5 Partial enlarged view;

[0030] Figure 7 A schematic structural diagram of an exemplary safety protection member provided by an embodiment of the present disclosure;

[0031] Figure 8 A schematic structural diagram of another exemplary safety protection member provided by an embodiment of the present disclosure;

[0032] Figure 9 A schematic layout structure diagram of yet another exemplary safety protection member on the bottom plate part provided by an embodiment of the present disclosure;

[0033] Figure 10 A schematic structural diagram of an exemplary positive electrode post provided by an embodiment of the present disclosure;

[0034] Figure 11 A schematic structural diagram of an exemplary sealing ring provided by an embodiment of the present disclosure.

[0035] The reference numerals respectively represent:

[0036] 001, battery cover plate;

[0037] 100, conductive cover plate; 11, first through hole; 12, second through hole; 13, third through hole;

[0038] 200, insulating backing plate;

[0039] 300, negative electrode post unit; 400, positive electrode post unit;

[0040] 31. Negative terminal; 41. Positive terminal; 411. Bottom plate part; 412. Cylindrical part;

[0041] 32 / 42. Sealing ring; 421. Annular step;

[0042] 33 / 43. Insulating spacer; 44. Safety protection part; 441. First part; 442. Second part;

[0043] 500. Explosion-proof valve; 51. Explosion-proof film; 600. Liquid injection hole;

[0044] 002. Battery cell; 0021. Negative tab; 0022. Positive tab; 0023. Insulating diaphragm;

[0045] 003. Battery housing. Detailed implementation manner

[0046] In the description of the embodiments of the present disclosure, it should be understood that the orientation or positional relationships indicated by terms such as "inner", "outer", "top", "bottom", "vertical", "horizontal", "height", "depth", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present disclosure 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. When the product is placed in different postures, the orientation may change. Therefore, it should not be construed as a limitation to the embodiments of the present disclosure.

[0047] For a secondary battery such as a lithium-ion battery, it generally includes: a battery cell, a battery housing, and a battery cover. The battery cover is welded to the battery housing to form a sealed cavity, and the battery cell is accommodated in the sealed cavity. The battery cover generally includes a conductive cover, an insulating gasket, a positive terminal unit, and a negative terminal unit. The positive terminal unit and the negative terminal unit are assembled on the stacked conductive cover and insulating gasket. Among them, the conductive cover is electrically connected to the battery housing, the negative terminal unit and the positive terminal unit are respectively electrically connected to the negative electrode and the positive electrode of the battery cell, and the insulating gasket is used to insulate the conductive cover from the battery cell.

[0048] The battery housing and the conductive cover of the battery cover are usually made of a metal material, such as aluminum, and the two are electrically connected through welding. Taking a lithium-ion battery as an example, when the potential of the battery housing with respect to the battery negative electrode drops to the corrosion potential of 0.26V, lithium ions will embed in the battery housing to form a lithium-aluminum alloy, resulting in negative short corrosion of the battery, and then causing the battery housing to leak liquid.

[0049] To avoid the potential of the battery case being too low and causing lithium insertion corrosion, in related technologies, a weak conduction spacer with weak conductivity is provided between the positive electrode post of the positive electrode post unit and the conductive cover plate. The weak conduction spacer is prepared by doping a conductive substance in an insulating material such as polyphenylene sulfide (PPS), ensuring a certain resistance value between the positive electrode post and the battery case, thereby preventing electrochemical corrosion of the battery case and the conductive cover plate and reducing the corrosion risk of the battery. At the same time, an insulating spacer is provided between the negative electrode post in the negative electrode post unit and the conductive cover plate to insulate the negative electrode post from the conductive cover plate.

[0050] However, for the weak conduction spacer prepared from a weakly conductive material such as conductive PPS, its resistance value is relatively low, resulting in a risk of short-circuit failure of the battery. For example, the weak conduction spacer is easily broken down at a higher voltage, leading to an external short circuit of the battery.

[0051] In view of the technical problems provided by the related technologies, embodiments of the present disclosure provide a battery, as shown in the attached Figure 1 - attached Figure 2 figure. The battery includes: a battery cover plate 001, an electrode assembly 002, and a battery case 003. The battery case 003 houses the electrode assembly 002; as shown in the attached Figure 3 - attached Figure 4 figure, the battery cover plate 001 includes a conductive cover plate 100, an insulating backing plate 200, a negative electrode post unit 300, and a positive electrode post unit 400. The negative electrode post unit 300 and the positive electrode post unit 400 are respectively disposed through the stacked conductive cover plate 100 and the insulating backing plate 200, and the negative electrode post unit 300 is electrically insulated from the conductive cover plate 100. The battery cover plate 001 is connected to and electrically conducts with the battery case 003 through the conductive cover plate 100. The battery cover plate 001 is respectively electrically connected to the negative electrode and the positive electrode of the electrode assembly 002 through its negative electrode post unit 300 and positive electrode post unit 400.

[0052] Regarding the assembly method of the negative electrode post unit 300 and the positive electrode post unit 400, Figure 3 - Figure 4 it is exemplified that the conductive cover plate 100 and the insulating backing plate 200 are stacked and provided with correspondingly communicating first through holes 11 and second through holes 12. The negative electrode post unit 300 is disposed through the first through hole 11, and the positive electrode post unit 400 is disposed through the second through hole 12.

[0053] In the battery provided by the embodiments of the present disclosure, the positive electrode column unit 400 of the battery cover plate 001 includes a positive electrode column 41 and a safety protection member 44. Among them, the positive electrode column 41 includes a column body portion 412 and a bottom plate portion 411 surrounding the outer side of one end of the column body portion 412. The safety protection member 44 is electrically connected to the bottom plate portion 411 and the surface of the conductive cover plate 100 facing the bottom plate portion 411, and the safety protection member 44 is used to fuse when the current flowing through the safety protection member 44 exceeds a threshold value. The threshold value involved here can be the current value generated when the battery is short-circuited.

[0054] If the resistance of the positive electrode of the battery to the battery case 003 is defined as R 1 , and the resistance of the negative electrode of the battery to the battery case 003 is defined as R 2 , and the battery voltage is defined as U, then the voltage of the battery case 003 to the negative electrode of the battery is (R 2 * U) / (R 1 + R 2 ). In the battery provided by the embodiments of the present disclosure, the safety protection member 44 can electrically connect the positive electrode column 41 and the conductive cover plate 100, and the conductive cover plate 100 is also electrically connected to the battery case 003. Then, the resistance R P between the positive electrode of the battery and the battery case 003 is close to 0. Then, the voltage of the battery case 003 to the negative electrode of the battery is approximately the battery voltage U. Usually, the voltage of the battery is 2.5V - 3.65V, which is much higher than the corrosion potential (0.2V) of the battery case 003 to the negative electrode of the battery. Therefore, the setting of the safety protection member 44 can effectively reduce the risk of negative short corrosion of the battery case 003.

[0055] It can be seen that in the battery provided by the embodiments of the present disclosure, by setting the safety protection member 44 in the positive electrode column unit 400, the positive electrode column 41 is electrically connected to the conductive cover plate 100 and the battery case 003, thereby increasing the potential of the battery case 003, eliminating the potential difference between the positive electrode column 41 and the battery case 003, effectively avoiding the lithium intercalation corrosion of the battery case 003, and reducing the negative short risk during normal operation of the battery. When the battery undergoes an abnormal short circuit (for example, the negative electrode of the battery is electrically connected to the battery case 003 or the conductive cover plate 100), a large current flows through the positive electrode column 41, and the safety protection member 44 can fuse when the current exceeds the threshold value, so that the connection between the positive electrode column 41 and the conductive cover plate 100 and the battery case 003 is disconnected, thereby cutting off the short-circuit current loop and avoiding the short-circuit risk of the battery.

[0056] In summary, for the battery provided in the embodiments of the present disclosure, under normal operating conditions of the battery, the battery cover plate 001 makes the potential of the battery housing 003 consistent with the potential of the positive electrode post 41, thereby effectively reducing the risk of negative short corrosion of the battery. In the case of an abnormal short circuit in the battery, the safety protection component 44 is melted to cut off the short circuit loop, improving the safety of the battery and reducing risks such as battery fire and explosion. In addition, the safety protection component 44 is located between the conductive cover plate 100 and the bottom plate portion 411 of the positive electrode post 41. This assembly position not only makes the assembly of the safety protection component 44 more convenient and efficient, but also does not affect the sealing assembly effect between the positive electrode post 41 and the conductive cover plate 100.

[0057] Compared with the related art solutions that set weak conductive spacers or insulating spacers in the positive electrode post unit, for the battery provided in the embodiments of the present disclosure, the battery cover plate 001 has both the functions of positive electrode - battery housing conduction and fusing, effectively avoiding the technical problems existing in the related art solutions.

[0058] In the embodiments of the present disclosure, the safety protection component 44 is a conductive component. In some examples, as shown in the attached Figure 5 - attached Figure 6 figure, the safety protection component 44 includes a connected first part 441 and a second part 442. Among them, the first part 441 is electrically connected to the bottom plate portion 411, and the second part 442 is electrically connected to the surface of the conductive cover plate 100 facing the bottom plate portion 411. The second part 442 is used to melt when the current flowing through the safety protection component 44 exceeds a threshold value.

[0059] By making the safety protection component 44 include a connected first part 441 and a second part 442, and by making the second part 442 be set to be able to melt when the current exceeds a threshold value, the size of the second part 442 is bound to be smaller to provide a current fusing structure. The smaller - sized second part 442 is located above the larger - sized first part 441, and the first part 441 plays a supporting role for the second part 442. In this way, the second part 442 is more likely to be stably and non - deformably assembled between the first part 441 and the conductive cover plate 100, thus ensuring the use stability of the safety protection component 44.

[0060] The second part 442 can be designed based on at least one of its structure and size, so that the second part 442 can self - fuse when the current exceeds the threshold value, that is, in the case of an abnormal short circuit in the battery, so that the safety protection component 44 can be used as a current fusing device to provide safety protection for the battery.

[0061] The second part 442 can be connected to any position on the first part 441 as long as the second part 442 can easily extend into the space between the first part 441 of the safety protection member 44 and the conductive cover plate 100. Exemplarily, the second part 442 is connected to the surface of the first part 441 facing the conductive cover plate 100 to simplify the connection between the second part 442 and the conductive cover plate 100.

[0062] In addition, the safety protection member 44 is electrically connected to the bottom plate portion 411 through the first part 441, and the safety protection member 44 is electrically connected to the surface of the conductive cover plate 100 facing the bottom plate portion 411 through the second part 442. For the "electrical connection" involved here, its implementation manner can be physical contact between two components or physical connection between two components (for example, plugging, welding, etc.).

[0063] In combination with the settings of other components in the positive electrode post unit 400 in the embodiments of the present disclosure, the structure and its arrangement manner of the safety protection member 44 are further described by way of example.

[0064] As shown in the Figure 4 drawing Figure 5 the positive electrode post unit 400 further includes: a sealing ring 42 and an insulating spacer 43. A part of the bottom plate portion 411 of the positive electrode post 41 abuts against the insulating backing plate 200, and the column portion 412 of the positive electrode post 41 penetrates through the second through hole 12; in the direction from the bottom plate portion 411 to the column portion 412, the sealing ring 42 and the insulating spacer 43 are sequentially sleeved outside the column portion 412. The sealing ring 42 is used to achieve mechanical sealing between the positive electrode post 41 and the conductive cover plate 100, and the insulating spacer 43 is used to achieve electrical isolation between the positive electrode post 41 itself and the conductive cover plate 100.

[0065] Further in combination with Figure 10 it can be seen that the positive electrode post 41 includes a bottom plate portion 411 and a column portion 412 connected coaxially. The bottom plate portion 411 extends outward along the radial direction of the column portion 412 to provide a stepped surface. Along the direction away from the column portion 412, the stepped surface of the bottom plate portion 411 is successively a stepped surface inner region, a stepped surface middle region, and a stepped surface outer region. The stepped surface inner region abuts against the surface of the sealing ring 42 facing away from the conductive cover plate 100, the stepped surface outer region abuts against the surface of the insulating backing plate 200 facing away from the conductive cover plate 100, and the space between the stepped surface middle region and the conductive cover plate 100 is used to accommodate the safety protection member 44 to allow the safety protection member 44 to be located between the conductive cover plate 100 and the bottom plate portion 411 of the positive electrode post 41.

[0066] In some embodiments, the positive electrode post unit 400 further includes: a sealing ring 42 sleeved outside the column portion 412, in combination with Figure 11It can be seen that the outer side of the sealing ring 42 has an annular step 421, and the annular step 421 is clamped between the conductive cover plate 100 and the bottom plate portion 411 (the other parts of the sealing ring 42 are tightly clamped between the inner peripheral surface of the conductive cover plate 100 and the outer peripheral surface of the column portion 412 of the positive electrode column 41). As shown in the appendix Figure 5 -Appendix Figure 7 As shown, the number of the first part 441 is single, and the first part 441 is a ring structure and sleeved outside the annular step 421 of the sealing ring 42.

[0067] See Figure 7 , by using a single first part 441 and making it a ring structure, the first part 441 is sleeved outside the annular step 421 of the sealing ring 42 by using its ring hole, which will not cause any impact on the assembly of the sealing ring 42 in the battery cover plate 001, thus ensuring the sealing effect of the battery cover plate 001. In addition, the bottom surface of the first part 441 is electrically connected to the top surface at the corresponding position on the bottom plate portion 411 of the positive electrode column 41. For example, the implementation manner of this electrical connection can be that the bottom surface of the first part 441 is in surface-to-surface contact with the corresponding area of the top surface of the bottom plate portion 411, and the two achieve electrical conduction in a physical contact manner. Compared with the physical connection method, the operation corresponding to the physical contact method is more convenient and efficient.

[0068] It can be seen that for this embodiment, when assembling the first part 441, based on its ring hole, it can be easily and efficiently sleeved outside the sealing ring 42, and its bottom is abutted against the bottom plate portion 411 of the positive electrode column 41. This not only helps to simplify the assembly difficulty of the safety protection part 44 and improve the assembly efficiency (that is, it has strong assemblability), but also the surface-to-surface contact method helps to improve the electrical conduction reliability between the first part 441 and the bottom plate portion 411. Moreover, the safety protection part 44 with a ring structure is sleeved outside the annular step 421 of the sealing ring 42, which will not affect the sealing performance of the battery cover plate 001.

[0069] For the first part 441 with a ring structure involved in the above embodiment, the inner ring shape and the outer ring shape can be the same or different, and the inner ring shape and the outer ring shape can independently be circular, square, pentagonal, hexagonal, etc.

[0070] In some examples, the first part 441 is a circular ring structure, that is, both its inner ring shape and outer ring shape are circular. The first part 441 with a circular ring structure is easier to fit the sealing ring 42, and the two are in clearance fit. The sealing ring 42 can also play a positioning role for the first part 441, ensuring that the position of the safety protection part 44 in the state of abutting against the bottom plate portion 411 is more stable and not easy to shift.

[0071] Of course, it is not excluded that the first part 441 can also be other annular structures, such as a rectangular annular structure, etc.

[0072] In the embodiments of the present disclosure, the axial direction of the positive electrode post 41 is defined as the vertical direction. The cross-sectional shape of the first part 441 includes but is not limited to a square, a rectangle, a circle, a trapezoid, etc. For example, the cross-sectional shape of the first part 441 can be a rectangular shape. In this way, the first part 441 is easier to form and prepare. Moreover, the first part 441 provides a plane to abut against the bottom plate part 411 of the positive electrode post 41, which is conducive to realizing the abutment in a surface-to-surface contact manner between the two, and realizing stable and reliable electrical conduction.

[0073] For the safety protection member 44 including the above-mentioned annular structure of the first part 441, the number of the second parts 442 included therein can be single or multiple. In order to improve the electrical conduction reliability between the safety protection member 44 and the conductive cover plate 100, the number of the second parts 442 can be multiple, which includes but is not limited to: 2, 3, 4, 5, 6 or more. In the case of an abnormal short circuit of the battery, in order to ensure that the safety protection member 44 can be reliably melted in time, the number of the second parts 442 can also be controlled within 6 or less. For example, Figure 7 It is exemplified that the number of the second parts 442 is 2.

[0074] The multiple second parts 442 are arranged in the following manner: along the circumferential direction of the first part 441, the multiple second parts 442 are spaced apart and distributed on the surface of the first part 441 facing the conductive cover plate 100.

[0075] In some examples, the distance between any two of the multiple second parts 442 is the same, so that the multiple second parts 442 are evenly spaced. When the second part 442 abuts against the conductive cover plate 100 and exerts a force on it, this is also beneficial for evenly applying forces of the multiple second parts 442 on the conductive cover plate 100.

[0076] The above describes the solution of arranging the first part 441 individually. In some other embodiments, as shown in the attached Figure 8 - attached Figure 9 As shown, the number of the first parts 441 can also be multiple. The multiple first parts 441 are sequentially distributed along the circumferential direction of the bottom plate part 411. For example, the multiple first parts 441 are evenly spaced. At least one second part 442 is connected to the surface of each first part 441 facing the conductive cover plate 100.

[0077] By making the first part 441 into multiple independent parts and connecting at least one second part 442 to its surface, on the premise of ensuring electrical conduction between the positive electrode post 41 and the conductive cover plate 100, the balanced arrangement of the safety protection part 44 can also be achieved.

[0078] For this implementation, the first part 441 can be a block structure, and its shape includes but is not limited to: arc-shaped block, cylindrical block, square block, rectangular block, etc. The first part 441 can abut against the bottom plate part 411 of the positive electrode post 41, or the first part 441 can also be connected to the bottom plate part 411 of the positive electrode post 41 by means of plugging, welding, etc., so as to realize the electrical conduction between the safety protection part 44 and the positive electrode post 41.

[0079] As described above, the positive electrode post unit 400 further includes: a sealing ring 42 sleeved outside the column body part 412. Figure 11 It can be known that the outer side of the sealing ring 42 has an annular step 421, and the annular step 421 is clamped between the conductive cover plate 100 and the bottom plate part 411. In some examples, as shown in the appendix Figure 8 The first part 441 has an arc-shaped cavity, and the first part 441 is sleeved outside the annular step 421 of the sealing ring 42 through the arc-shaped cavity. Among them, the diameter corresponding to the arc-shaped cavity is adapted to the outer diameter of the annular step 421 of the sealing ring 42, so that the two are in clearance fit. In this way, the sealing ring 42 plays a certain limiting role on the first part 441.

[0080] When assembling the first part 441 with an arc-shaped cavity, due to its arc-shaped cavity, it is easy and efficient to sleeve it on a partial area outside the sealing ring 42. On this basis, making the bottom of the first part 441 abut against the bottom plate part 411 of the positive electrode post 41 for surface-to-surface contact can realize the electrical conduction between the safety protection part 44 and the positive electrode post 41, and at the same time, this also helps to simplify the assembly difficulty of the safety protection part 44. Similarly, this implementation method will not affect the sealing performance of the battery cover plate 001.

[0081] As shown in the appendix Figure 8 The first part 441 is arranged in two symmetrical parts, each first part 441 is a semi-circular arc-shaped block, and each first part 441 has a semi-circular arc-shaped cavity. After the two first parts 441 are butted, a circular ring structure is formed.

[0082] Of course, it is not excluded that the first part 441 can also be arranged in the shape of a rectangular block, and the first part 441 and the bottom plate part 411 of the positive electrode post 41 can be connected by means of welding, plugging, etc. to realize electrical conduction.

[0083] Define the axial direction of the positive electrode post 41 as the vertical direction. The cross-sectional shape of the first part 441 in this embodiment includes, but is not limited to, a square, a rectangle, a circle, a trapezoid, etc.

[0084] For any of the first parts 441 involved in the above embodiments of the present disclosure, in order to adapt to the size of the battery cover plate of the current conventional secondary battery, the thickness of the first part 441 can be 0.3 mm - 1 mm, and the height can be 1 mm - 2 mm. Among them, the thickness of the first part 441 refers to the dimension in the direction parallel to the plate surface where the bottom plate portion 411 of the positive electrode post 41 is located, and the height of the first part 441 refers to the dimension in the direction parallel to the axial direction of the positive electrode post 41.

[0085] For any of the safety protection members 44 involved in the above embodiments of the present disclosure, the second part 442 is at least one of a convex block shape, a needle shape, a sheet shape, and a filament shape.

[0086] The convex-block-shaped second part 442 can be in contact with the conductive cover plate 100 to achieve electrical conduction between the two; the needle-shaped second part 442 can be inserted into the corresponding jacks provided on the conductive cover plate 100 in an insertion manner to achieve electrical conduction between the two; the sheet-shaped or filament-shaped second part 442 can be connected to the conductive cover plate 100 by welding to achieve electrical conduction between the two. The second parts 442 of the above various shapes can all easily provide a current fusing structure.

[0087] For any of the second parts 442 involved above, it can be an independent component and connected to the first part 441 to form the safety protection member 44, or it can be integrally formed with the first part 441 to obtain a safety protection member 44 with an integrated structure.

[0088] In some examples, the second part 442 can be integrally formed with the first part 441. For example, a safety protection member 44 with an integrated structure can be prepared by stamping, 3D printing, etc. This not only helps to improve the structural stability of the safety protection member 44, but also is beneficial to simplifying the assembly of the safety protection member 44 in the battery cover plate 001.

[0089] In some examples, as shown in the attached Figure 6 figure, the second part 442 in the safety protection member 44 is in a convex block shape, and the end of the second part 442 facing away from the first part 441 is in contact with the conductive cover plate 100. The convex-block-shaped second part 442 achieves electrical conduction with the conductive cover plate 100 through the contact method, which is beneficial to simplifying the assembly of the safety protection member 44 in the battery cover plate 001 and improving the assembly efficiency.

[0090] Regarding the shape of the convex second part 442, it can be a cylindrical block, a prismatic block (such as a rectangular block), a trapezoidal block, etc., which is beneficial to improving the contact stability between it and the conductive cover plate 100.

[0091] Regarding the dimensions of the convex second part 442, its thickness can be the same as or different from that of the first part 441. In some examples, the thickness of the second part 442 can be 0.1 mm - 1 mm, and the height can be 0.5 mm - 2 mm. Here, the thickness of the second part 442 refers to the dimension in the direction parallel to the plate surface of the bottom plate part 411 of the positive electrode post 41, and the height of the second part 442 refers to the dimension in the direction parallel to the axial direction of the positive electrode post 41.

[0092] By defining the dimensions of the second part 442 as above, it can be ensured that the second part 442 can be melted in time when the battery short - circuits.

[0093] As shown in the Figure 6 attachment, the outer side of the sealing ring 42 has an annular step 421. The annular step 421 is clamped between the conductive cover plate 100 and the bottom plate part 411 of the positive electrode post 41, and the end of the second part 442 facing away from the first part 441 can be higher than or flush with the end of the annular step 421 on the same side. For example, the end of the second part 442 facing away from the first part 441 is 0.1 mm - 0.5 mm higher than the end of the annular step 421 on the same side.

[0094] By making the axial height of the convex second part 442 equal to or slightly higher than the height of the annular step 421, it is ensured that the second part 442 can stably contact the conductive cover plate 100 to enhance the contact stability between the two.

[0095] Regarding any of the safety protection parts 44 involved in the above - mentioned embodiments of the present disclosure, it is made of a conductive material. The conductive material can be a metal element or a metal alloy. The metal alloy can be aluminum, iron, copper, magnesium, zinc, tin, steel, aluminum alloy, lead - tin alloy, etc. The materials of the first part 441 and the second part 442 in the safety protection part 44 can be the same or different. For example, when the first part 441 and the second part 442 are integrally formed, they are made of the same material.

[0096] In some examples, the present disclosure provides such a battery cover plate 001, whose safety protection part 44 includes a first part 441 and a second part 442 that are integrally formed and connected. The first part 441 is a circular - ring structure, and the number of the second parts 442 is multiple, for example, two. The multiple second parts 442 are symmetrically arranged on the surface of the first part 441 facing away from the bottom plate part 411 of the positive electrode post 41, and each second part 442 is a convex block, such as a rectangular convex block.

[0097] The safety protection component 44 is in surface-to-surface contact with the bottom plate portion 411 through the first portion 441 to achieve electrical conduction. The safety protection component 44 is in contact with the surface of the conductive cover plate 100 facing the bottom plate portion 411 through the second portion 442 to achieve electrical conduction. The second portion 442 is used to fuse when the current exceeds the threshold value.

[0098] The assembly process of the positive electrode post unit 400 involved in this example can be as follows: First, a sealing ring 42 is sleeved outside the positive electrode post 41, and the safety protection component 44 is sleeved outside the sealing ring 42 through its first portion 441. Then, the positive electrode post 41 with the sealing ring 42 and the safety protection component 44 penetrates through the first through hole 11 in the conductive cover plate 100 and the insulating backing plate 200, so that the bottom plate portion 411 of the positive electrode post 41 abuts against the insulating backing plate 200 at the same time. Meanwhile, the safety protection component 44 abuts against the corresponding area on the bottom surface of the conductive cover plate 100 through its second portion 442, and the sealing ring 42 abuts against the corresponding area on the bottom surface of the conductive cover plate 100 through its annular step 421. Subsequently, the insulating spacer 43 (the material thereof can be, for example, PPS) is injection-molded, and the assembly of the positive electrode post unit 400 can be completed.

[0099] The above describes the arrangement manner of the safety protection component 44 in the battery cover plate 001. For the arrangement manner of the positive electrode post 41, the sealing ring 42, and the insulating spacer 43 in the positive electrode post unit 400 in the battery cover plate 001, reference can be made to Figure 3 and Figure 4 for an exemplary description.

[0100] In the embodiment of the present disclosure, the conductive cover plate 100 and the insulating backing plate 200 are stacked. Among them, a receiving groove is provided on the side of the insulating backing plate 200 facing away from the conductive cover plate 100. The bottom plate portion 411 of the positive electrode post 41 is embedded in the receiving groove of the insulating backing plate 200, and the outer region of the stepped surface of the bottom plate portion 411 abuts against the top wall of the receiving groove of the insulating backing plate 200.

[0101] The sealing ring 42 includes a main body portion and an annular step 421 disposed outside the main body portion. The sealing ring 42 is tightly sleeved outside the column body portion 412 of the positive electrode post 41 through its main body portion, and the outer peripheral surface of the main body portion of the sealing ring 42 is tightly abutted against the inner peripheral surface of the first through hole of the conductive cover plate 100. The two ends of the annular step 421 of the sealing ring 42 are tightly abutted against the inner region of the stepped surface of the bottom plate portion 411 and the conductive cover plate 100 respectively. Thus, the sealing ring 42 realizes physical isolation between the positive electrode post 41 and the conductive cover plate 100.

[0102] The insulating spacer 43 can be formed by injection molding. Exemplarily, the insulating spacer 43 includes a coaxial connecting sleeve portion and a panel portion. The panel portion extends in a radially outward direction relative to the sleeve portion to form a stepped surface. The insulating spacer 43 covers a partial surface of the conductive cover plate 100 through the stepped surface of its panel portion. The insulating spacer 43 tightly fills the gap between the positive electrode post 41 and the pore wall of the first through hole of the conductive cover plate 100 through its sleeve portion, and is positioned with each other through a positioning structure, so that the insulating spacer 43 cannot freely escape in both the axial direction and the radial direction. Thus, the insulating spacer 43 realizes electrical isolation between the positive electrode post 41 and the conductive cover plate 100.

[0103] The assembly manner of the negative electrode post unit 300 in the battery cover plate 001 is basically the same as that of the positive electrode post unit 400, except that the safety protection member 44 is not provided in the negative electrode post unit 300, as shown in the attached Figure 3 and the attached Figure 4 As shown, the negative electrode post unit 300 includes a negative electrode post 31, a sealing ring 32, and an insulating spacer 33. Among them, for the structure and arrangement manner of the negative electrode post 31, reference can be made to the structure and arrangement manner of the positive electrode post 41; for the structure and arrangement manner of the sealing ring 32, reference can be made to the structure and arrangement manner of the sealing ring 42; for the structure and arrangement manner of the insulating spacer 33, reference can be made to the structure and arrangement manner of the insulating spacer 43, and details will not be elaborated here one by one.

[0104] For any of the battery cover plates 001 involved in the above embodiments of the present disclosure, as shown in the attached Figure 3 and the attached Figure 4 As shown, the battery cover plate 001 further includes: an explosion-proof valve 500 and a liquid injection hole 600; the conductive cover plate 100 and the insulating gasket 200 have correspondingly communicated third through holes 13, and the explosion-proof valve 500 is arranged in the third through hole 13; the liquid injection hole 600 penetrates through the conductive cover plate 100 and the insulating gasket 200.

[0105] When the water content in the battery cell of a battery, such as a lithium-ion battery, exceeds the standard, the SEI film is unstable, the lithium-ion battery is overcharged or over-discharged, the lithium-ion battery is short-circuited, squeezed or other abuse conditions occur, it will cause gas generation, ignition, and even explosion inside the battery. To solve this technical problem, an explosion-proof valve 500 is provided to release the gas generated inside the battery.

[0106] Exemplarily, as shown in the attached Figure 3 and the attached Figure 4 As shown, the explosion-proof valve 500 includes an explosion-proof sheet 51 covering the third through hole 13. When gas is generated inside the battery and the gas pressure reaches the bursting pressure of the explosion-proof valve 500, the explosion-proof sheet 51 ruptures, so that the gas inside the battery is discharged, preventing the battery from exploding due to bloating.

[0107] In addition, for any of the batteries mentioned in the embodiments of the present disclosure, as shown in the attachedFigure 2 As shown, its battery cell 002 includes a bare battery cell and an insulating separator 0023 coated on the outside of the bare battery cell. A negative electrode tab 0021 and a positive electrode tab 0022 are provided at the top of the bare battery cell. The battery cover plate 001 is electrically connected to the negative electrode tab 0021 and the positive electrode tab 0022 of the battery cell 002 through the negative electrode column 31 of the negative electrode column unit 300 and the positive electrode column 41 of the positive electrode column unit 400 respectively.

[0108] The negative electrode tab 0021 can be directly electrically connected to the negative electrode column 31 of the battery cover plate 001, or the negative electrode tab 0021 can also be electrically connected to the negative electrode column 31 of the battery cover plate 001 through a connecting piece. The positive electrode tab 0022 can be directly electrically connected to the positive electrode column 41 of the battery cover plate 001, or the positive electrode tab 0022 can also be electrically connected to the positive electrode column 41 of the battery cover plate 001 through another connecting piece.

[0109] For the types of batteries involved in the embodiments of the present disclosure, they include but are not limited to: lithium-ion batteries, sodium-ion batteries, etc.

[0110] On the other hand, the embodiments of the present disclosure also provide a battery pack, which includes a plurality of batteries as described above, and the plurality of batteries are connected in series or in parallel.

[0111] The battery pack provided by the embodiments of the present disclosure has all the advantages of the batteries provided by the embodiments of the present disclosure.

[0112] On yet another aspect, the embodiments of the present disclosure also provide an energy storage system, which includes a power converter and at least one of the above-mentioned battery packs; the power converter is used to perform power conversion on the voltage output by the battery pack and output it to the power grid or the load, and / or perform power conversion on the voltage output by an external power source and output it to the battery pack.

[0113] The battery pack provided by the embodiments of the present disclosure has all the advantages of the batteries or battery packs provided by the embodiments of the present disclosure.

[0114] The above is only for the convenience of those skilled in the art to understand the technical solutions of the present disclosure, and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A battery, characterized in that: The battery comprises: a battery cell (002); A battery housing (003), wherein the battery housing (003) accommodates the battery cell (002); A battery cover plate (001), comprising a conductive cover plate (100), an insulating pad (200), a negative electrode column unit (300) and a positive electrode column unit (400), wherein the negative electrode column unit (300) and the positive electrode column unit (400) respectively penetrate the conductive cover plate (100) and the insulating pad (200) which are stacked, and the negative electrode column unit (300) is electrically insulated from the conductive cover plate (100); the conductive cover plate (100) is connected to and electrically conductive with the battery housing (003), and the negative electrode column unit (300) and the positive electrode column unit (400) are respectively electrically connected to the negative electrode lug (0022) and the positive electrode lug (0023) of the battery cell (002); The positive electrode column unit (400) comprises a positive electrode column (41) and a safety protection member (44); the positive electrode column (41) comprises a column body (412) and a bottom plate (411) arranged around the outside of one end of the column body (412); The safety protection member (44) is electrically connected to the bottom plate portion (411) and the surface of the conductive cover plate (100) facing the bottom plate portion (411), respectively, and the safety protection member (44) is used to fuse when the current flowing through the safety protection member (44) exceeds a threshold value.

2. The battery according to claim 1, characterized in that The safety protection member (44) comprises a first part (441) and a second part (442) connected to each other; The first part (441) is electrically connected to the bottom plate portion (411), the second part (442) is electrically connected to the surface of the conductive cover plate (100) facing the bottom plate portion (411), and the second part (442) is used to fuse when the current exceeds a threshold value.

3. The battery according to claim 2, characterized in that The positive electrode column unit (400) further comprises: a sealing ring (42) sleeved on the outside of the column portion (412), the outer side of the sealing ring (42) having an annular step (421), and the annular step (421) is sandwiched between the conductive cover plate (100) and the bottom plate portion (411); The number of the first part (441) is one, and the first part (441) is an annular structure and is sleeved on the outside of the annular step (421).

4. The battery according to claim 3, characterized in that There are multiple second parts (442), and along the circumferential direction of the first part (441), the multiple second parts (442) are distributed at intervals on the surface of the first part (441) facing the conductive cover plate (100).

5. The battery according to claim 3, characterized in that The number of the first parts (441) is multiple, and the multiple first parts (441) are distributed in sequence along the circumferential direction of the bottom plate part (411); At least one second part (442) is connected to a surface of each first part (441) facing the conductive cover plate (100).

6. The battery according to claim 5, characterized in that The first part (441) has an arc-shaped cavity, and the first part (441) is sleeved on the outside of the annular step (421) through the arc-shaped cavity.

7. The battery according to any one of claims 3 to 6, characterized in that: The second part (442) is in the shape of a convex block, a needle, a sheet, or a thread.

8. The battery according to claim 7, characterized in that The second part (442) is in the shape of a convex block, and the end of the second part (442) that is away from the first part (441) is in contact with the conductive cover plate (100).

9. The battery according to claim 7, characterized in that The end of the second portion (442) facing away from the first portion (441) is higher than or level with the end of the annular step (421) located on the same side.

10. A battery pack, characterized in that: The battery pack comprises a plurality of batteries as described in any one of claims 1 to 9, and the plurality of batteries are connected in series or in parallel.

11. An energy storage system, characterized in that: The energy storage system includes a power converter and at least one battery as described in claim 10. The power converter is used to convert the voltage output by the battery pack into power and output it to a power grid or a load, and / or to convert the voltage output by an external power source into power and output it to the battery pack.

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