Current collector, bipolar battery and electric apparatus

Abstract

An electric apparatus (200). The electric apparatus (200) comprises a bipolar battery (100), wherein the bipolar battery (100) comprises current collectors (10); and each current collector (10) comprises a support structure (11), and a first fixing structure (12) and a second fixing structure (13), which are respectively arranged on two sides of the support structure (11) that face away from each other. When at least two current collectors (10) are stacked, among two adjacent current collectors (10) of the bipolar battery (100), the first fixing structure (12) of one current collector (10) is detachably connected to the second fixing structure (13) of the other current collector (10), such that the two support structures (11) adjacent to each other, and the first fixing structure (12) and the second fixing structure (13), which are detachably connected to each other, jointly form an accommodating cavity (105) by means of enclosure, the accommodating cavity (105) being configured to accommodate an electrolytic solution.

Description

Current collector, bipolar battery and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202420254764.2, filed with the State Intellectual Property Office of China on January 31, 2024, entitled “Current Collector, Bipolar Battery and Electrical Equipment,” the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a current collector, a bipolar battery, and an electrical device. Background Art

[0004] Bipolar pole pieces are coated with active materials of different polarities on opposite sides of a current collector. Multiple bipolar pole pieces and multiple electrolytes are stacked in series to form a bipolar battery. However, during the stacking process, the pole pieces can easily slip and become misaligned due to the gravity or vibration of the current collectors. This can lead to contact with active materials of different polarities, causing short circuits and potentially safety issues. Furthermore, sealing adjacent current collectors is difficult, and pre-formation sealing hinders the timely discharge of gas generated during formation, which can adversely affect battery safety.

[0005] Public content

[0006] The present disclosure provides a current collector, a bipolar battery, and an electrical device that are conducive to improving assembly efficiency and safety.

[0007] In the first aspect, an embodiment of the present disclosure provides a current collector, which includes: a support structure; a first fixed structure; and a second fixed structure, wherein the first fixed structure and the second fixed structure are respectively arranged on opposite sides of the support structure; when at least two of the current collectors are stacked, in two adjacent current collectors, the first fixed structure of one current collector is detachably connected to the second fixed structure of the other current collector, so that the two adjacent support structures and the first fixed structure and the second fixed structure that are detachably connected to each other jointly form a accommodating cavity, which is used to accommodate an electrolyte.

[0008] According to the first aspect, in a possible implementation, the first fixing structure and the second fixing structure are both snap-fit ​​structures, and in two adjacent current collectors, the first fixing structure of one current collector is snap-fitted to the second fixing structure of the other current collector.

[0009] According to the first aspect, in a possible implementation, the first fixing structure is provided with a first clamping groove, and the first clamping groove is used to clamp the second fixing structure on the adjacent current collector when at least two current collectors are stacked.

[0010] According to the first aspect, in a possible implementation, the second fixed structure is provided with a second card groove. When at least two of the current collectors are stacked, in the first fixed structure and the second fixed structure that are engaged with each other, the end of the first fixed structure is inserted into the second card groove of the second fixed structure, and the end of the second fixed structure is inserted into the first card groove of the first fixed structure, so as to form a continuously bent sealing surface between the first fixed structure and the second fixed structure.

[0011] According to the first aspect, in a possible implementation manner, the first fixing structure is bent to form the first clamping slot, and the second fixing structure is bent to form the second clamping slot.

[0012] According to the first aspect, in a possible implementation manner, the end portion of the first fixing structure and the end portion of the second fixing structure are arc-shaped.

[0013] According to the first aspect, in a possible implementation manner, at least one of the first fixing structure and the second fixing structure has thermal adhesiveness.

[0014] According to the first aspect, in a possible implementation manner, both opposite sides of the support structure have current collecting layers, and the first fixing structure and the second fixing structure are arranged on the periphery of the current collecting layer on the same side.

[0015] According to the first aspect, in a possible implementation manner, the support structure includes a support layer and two metal foils, and the two metal foils are respectively arranged on opposite sides of the support layer to form the current collecting layer.

[0016] According to the first aspect, in a possible implementation manner, at least a portion of the support layer exposed from the metal foil is insulating, and the first fixing structure and the second fixing structure are provided on the insulating portion of the support layer.

[0017] According to the first aspect, in a possible implementation manner, a region of the support layer covered by the current collecting layer is at least partially conductive.

[0018] In a second aspect, an embodiment of the present disclosure further provides a bipolar battery, comprising: a positive electrode plate; a negative electrode plate; and the current collector described in the first aspect, wherein a plurality of the current collectors are stacked between the positive electrode plate and the negative electrode plate, and are stacked in a direction from the positive electrode plate toward the negative electrode plate.

[0019] According to the second aspect, in one possible implementation, a third fixing structure is provided on the side of the positive electrode plate facing the current collector, and the third fixing structure of the positive electrode plate is engaged with the first fixing structure of the adjacent current collector to form a receiving cavity between the positive electrode plate and the support structure of the adjacent current collector; a fourth fixing structure is provided on the side of the negative electrode plate facing the current collector, and the fourth fixing structure of the negative electrode plate is engaged with the second fixing structure of the adjacent current collector to form a receiving cavity between the negative electrode plate and the support structure of the adjacent current collector.

[0020] According to the second aspect, in a possible implementation, along the direction from the positive electrode plate to the negative electrode plate, a positive electrode material layer, a separator and a negative electrode material layer are sequentially stacked in the accommodating cavity, the positive electrode material layer is provided on the positive electrode plate or the current collector, and the negative electrode material layer is provided on the negative electrode plate or the current collector.

[0021] According to the second aspect, in a possible implementation manner, a projection of the separator along the stacking direction at least completely covers a projection of the positive electrode material layer along the stacking direction and a projection of the negative electrode material layer along the stacking direction.

[0022] According to the second aspect, in a possible implementation manner, the diaphragm is coated with a solid electrolyte; or the receiving cavity is filled with a liquid electrolyte.

[0023] According to the second aspect, in one possible implementation, the bipolar battery further includes a shell, the current collector, the positive electrode material layer, the separator and the negative electrode material layer are all arranged in the shell, a portion of the positive electrode plate extends out of the shell to form a positive electrode lead-out portion, and a portion of the negative electrode plate extends out of the shell to form a negative electrode lead-out portion.

[0024] In a third aspect, an embodiment of the present disclosure further provides a bipolar battery, comprising: a positive electrode plate; a negative electrode plate; and the current collector described in the first aspect, wherein a plurality of the current collectors are stacked between the positive electrode plate and the negative electrode plate, and are stacked in a direction from the positive electrode plate toward the negative electrode plate, and among two adjacent current collectors, the first fixing structure of one current collector is adhered to the second fixing structure of the other current collector to seal the accommodating cavity.

[0025] According to the third aspect, in one possible implementation, a third fixing structure is provided on the side of the positive electrode plate facing the current collector, and the third fixing structure of the positive electrode plate is adhered to the first fixing structure of the adjacent current collector to form a receiving cavity between the positive electrode plate and the adjacent support structure of the current collector; a fourth fixing structure is provided on the side of the negative electrode plate facing the current collector, and the fourth fixing structure of the negative electrode plate is adhered to the second fixing structure of the adjacent current collector to seal the receiving cavity, so as to form a receiving cavity between the negative electrode plate and the adjacent support structure of the current collector.

[0026] In a fourth aspect, an embodiment of the present disclosure further provides an electrical device, wherein the electrical device comprises the bipolar battery described in the second aspect or the third aspect.

[0027] The present disclosure provides a current collector, a bipolar battery, and an electrical device. A first fixing structure and a second fixing structure are provided on opposite sides of the support structure of the current collector. In the multiple current collectors of the bipolar battery, the first fixing structure and the second fixing structure cooperate to fasten two adjacent support structures to achieve temporary positioning, which can prevent the two adjacent current collectors from being misaligned during the battery assembly process, thereby improving assembly efficiency. In addition, the temporary positioning of the two adjacent current collectors during stacking can improve the positional accuracy of the two adjacent current collectors, avoid short circuits between the two adjacent current collectors, and improve safety. In addition, the first fixing structure and the second fixing structure form a accommodating cavity between the two adjacent support structures. The first fixing structure and the second fixing structure isolate the components in the accommodating cavity, reduce the probability of electrolyte leakage and short circuits between the internal and external structures of the sealed cavity, and improve the sealing and safety of the finished battery. In addition, during the formation process, the internal gas production of the battery increases the internal gas pressure. Under the action of the internal gas pressure, the connection between the first fixing structure and the second fixing structure can open a channel to facilitate exhaust, thereby increasing the safety and cycle life of the battery during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments.

[0029] FIG1 is a schematic diagram of a bipolar battery provided in accordance with a first embodiment of the present disclosure.

[0030] FIG2 is a schematic diagram of a current collector of a bipolar battery provided in the first embodiment of the present disclosure.

[0031] FIG3 is another schematic diagram of the current collector of the bipolar battery provided in the first embodiment of the present disclosure.

[0032] FIG4 is a schematic diagram of two current collectors provided in a stacked state according to the first embodiment of the present disclosure.

[0033] FIG5 is a process flow chart of a bipolar battery provided in the first embodiment of the present disclosure.

[0034] FIG6 is a schematic diagram of exhaust during the formation process of two current collectors stacked in the first embodiment of the present disclosure.

[0035] FIG7 is a schematic block diagram of an electric device according to an embodiment of the present disclosure.

[0036] Figure numerals: 200, electrical equipment; 100, bipolar battery; 10, current collector; 11, supporting structure; 111, supporting layer; 112, metal foil; 113, current collecting layer; 12, first fixing structure; 121, first card slot; 13, second fixing structure; 131, second card slot; 20, positive electrode plate; 21, third fixing structure; 22, positive electrode lead-out portion; 30, negative electrode plate; 31, fourth fixing structure; 32, negative electrode lead-out portion; 40, positive electrode material layer; 50, diaphragm; 60, negative electrode material layer; 101, outer casing; 105, accommodating cavity; 103, battery cell. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0038] The following descriptions of the various embodiments are provided with reference to the accompanying drawings to illustrate specific embodiments in which the present disclosure may be implemented. Directional terms herein, such as "upper," "lower," "front," "back," "left," "right," "inner," "outer," and "side," are used solely with reference to the directions in the accompanying drawings. Therefore, the use of directional terms is intended to better and more clearly illustrate and understand the present disclosure, and is not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present disclosure.

[0039] Furthermore, component numbers herein, such as "first," "second," and the like, are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" in this disclosure, unless otherwise specified, include both direct and indirect connections (couplings).

[0040] Bipolar batteries are used to power electrical devices. The electrical devices may be vehicles. It is understood that the present disclosure is not limited to vehicles; bipolar batteries may also be used in other fields, such as power equipment, communications equipment, medical equipment, industrial automation equipment, and the like.

[0041] Referring to Figures 1 and 2 , the present disclosure provides a bipolar battery 100. In a first embodiment, the bipolar battery 100 includes a housing 101 and a battery cell 103 housed within the housing 101. The housing 101 is used to protect the battery cell 103. The battery cell 103 includes a plurality of current collectors 10, a positive electrode material layer 40, a separator 50, and a negative electrode material layer 60, as well as a positive electrode plate 20 and a negative electrode plate 30 located on both sides of the battery cell 103 in the stacking direction. The plurality of current collectors 10 are stacked along a first direction and positioned between the positive electrode plate 20 and the negative electrode plate 30. The first direction is the direction from the positive electrode plate 20 to the negative electrode plate 30. The positive electrode material layer 40, the separator 50, and the negative electrode material layer 60 are stacked between the positive electrode plate 20 and adjacent current collectors 10, between two adjacent current collectors 10, and between the current collector 10 and the negative electrode plate 30. The separator 50 is a specially formed polymer film with a microporous structure that allows metal ions to pass freely, but not electrons. The cavity 105 contains an electrolyte. Electrons travel from the negative electrode material layer 60 through an external circuit to the positive electrode material layer 40. Metal ions (charge carriers in the electrolyte, such as sodium or lithium ions) travel from the negative electrode material layer 60 through the electrolyte and the microporous structure of the separator 50 to the positive electrode material layer 40. There, they combine with the electrons that have traveled through the external circuit to the positive electrode material layer 40, completing the discharge process.

[0042] The positive electrode material layer 40 can be selected from positive electrode active materials commonly used in the art, such as at least one of Na / Ni / Fe / Mn layered oxides, sodium vanadium phosphate, sodium iron pyrophosphate, lithium iron phosphate, lithium manganese iron phosphate, and ternary materials. The negative electrode material layer 60 can be selected from negative electrode active materials commonly used in the art, such as at least one of soft carbon, hard carbon, artificial graphite, and natural graphite. The outer shell 101 can be a two-component outer packaging film of PP (polypropylene) and PET (polyethylene terephthalate). Of course, the outer shell 101 can also be an aluminum-plastic film. The present disclosure does not limit the material of the outer shell 101. A portion of the positive electrode plate 20 extends out of the housing 101 to form a positive electrode lead-out portion 22, and a portion of the negative electrode plate 30 extends out of the housing 101 to form a negative electrode lead-out portion 32. The positive electrode lead-out portion 22 and the negative electrode lead-out portion 32 are used to connect to electrical equipment to supply power to the electrical equipment. The positive electrode lead-out portion 22 and the negative electrode lead-out portion 32 can be located on the same side of the housing 101 or on different sides of the housing 101. Of course, the housing 101 can also be a steel shell or an aluminum shell. At least one of the positive electrode plate 20 and the negative electrode plate 30 can be electrically connected to a large surface of the steel shell or aluminum shell to achieve high-power charging and discharging.

[0043] Referring to Figures 2 and 3, the current collector 10 includes a support structure 11 and a first fixing structure 12 and a second fixing structure 13 respectively arranged on opposite sides of the support structure 11. The support structure 11 includes a support layer 111 and metal foils 112 respectively arranged on both sides of the support layer 111. The metal foils 112 serve as current collecting layers 113 of the support structure 11. The positive electrode material layer 40 and the negative electrode material layer 60 are respectively coated on the metal foils 112 on both sides. The current collecting layer 113 is used to collect the current generated between the positive electrode material layer 40 and the negative electrode material layer 60. Providing the support layer 111 between the two layers of the current collector 10 can prevent the occurrence of internal short circuits and negative electrode oxidation when traditional metal foils have holes. The first fixing structure 12 and the second fixing structure 13 are arranged on the periphery of the current collecting layer 113 on the same side. The first fixing structure 12 is connected to the side of the support layer 111 where the negative electrode material layer 60 is located, and the first fixing structure 12 is arranged on the periphery of the metal foil 112 connected to the negative electrode material layer 60; the second fixing structure 13 is connected to the side of the support layer 111 where the positive electrode material layer 40 is located, and the second fixing structure 13 is arranged on the periphery of the metal foil 112 connected to the positive electrode material layer 40.

[0044] The support structure 11 is a plate-like structure, and the projections of the first fixing structure 12 and the second fixing structure 13 on the support structure 11 are both annular. The projection shapes of the first fixing structure 12 and the second fixing structure 13 are adapted to the shape of the support structure 11. That is, when the support structure 11 is a square plate, the corresponding first fixing structure 12 and the second fixing structure 13 are overall square rings; when the support structure 11 is a circular plate, the corresponding first fixing structure 12 and the second fixing structure 13 are overall circular rings. Of course, the support structure 11, the first fixing structure 12, and the second fixing structure 13 can also have other shapes.

[0045] Please refer to Figures 2 and 4. When at least two current collectors 10 are stacked, in two adjacent current collectors 10, the first fixing structure 12 of one current collector 10 is detachably connected to the second fixing structure 13 of the other current collector 10, so that the two adjacent support structures 11 and the first fixing structure 12 and the second fixing structure 13 that are detachably connected to each other jointly form a accommodating cavity 105.

[0046] In this embodiment, the first fixing structure 12 is provided on the side of the support structure 11 connected to the negative electrode material layer 60, and the second fixing structure 13 is provided on the side of the support structure 11 connected to the positive electrode material layer 40. The first fixing structure 12 and the second fixing structure 13 are arranged opposite to each other along a first direction.

[0047] The support structure 11 of the current collector 10 is provided with a first fixing structure 12 and a second fixing structure 13 on both sides along the first direction. In the multiple current collectors 10 of the bipolar battery 100, the first fixing structure 12 and the second fixing structure 13 cooperate to form a receiving cavity 105 between two adjacent support structures 11, isolating a pair of positive / negative electrode material layers that generate current from other pairs of positive / negative electrode material layers. When the electrolyte in the receiving cavity 105 is a liquid electrolyte, the receiving cavity 105 formed by the first fixing structure 12 and the second fixing structure 13 can also reduce the risk of leakage of the internal liquid electrolyte during battery assembly, thereby reducing the risk of short circuits between different electrodes and improving the sealing and safety of the finished battery. At the same time, the first fixing structure 12 and the second fixing structure 13 cooperate and tighten to achieve temporary positioning of the two adjacent current collectors 10, prevent misalignment between the two adjacent current collectors 10 during battery assembly, improve the position accuracy of the two adjacent current collectors 10, avoid short circuits between the two adjacent current collectors 10, improve assembly efficiency and improve safety. During the formation process, the internal gas production of the battery increases the internal air pressure. Under the action of the internal air pressure, a channel can be opened at the connection between the first fixing structure 12 and the second fixing structure 13 to facilitate exhaust, thereby increasing the safety and cycle life of the battery during use.

[0048] In the above embodiment, the first fixing structure 12 and the second fixing structure 13 can be connected by snap fastening, or temporarily fixed by interference fit, clamps, slots, etc. The present disclosure does not limit the connection form of the first fixing structure 12 and the second fixing structure 13.

[0049] The following description assumes that the first fixing structure 12 and the second fixing structure 13 are connected by a snap-fit ​​method. For the convenience of description, the current collector 10 close to the positive electrode plate 20 of the two adjacent current collectors 10 is defined as the first current collector, and the current collector 10 close to the negative electrode plate 30 is defined as the second current collector.

[0050] As shown in Figure 2, a first slot 121 is provided on the first fixing structure 12. When at least two current collectors 10 are stacked, the end of the second fixing structure 13 of the first current collector 10 is clamped in the first slot 121 formed by the first fixing structure 12 of the second current collector. At this time, the end of the second fixing structure 13 is in contact with the inner wall surface of the first slot 121 to achieve a seal. When stacking the current collectors 10, positioning and locking can be achieved through the cooperation of the first fixing structure 12 and the second fixing structure 13, without the need to additionally control the position accuracy of the current collectors 10 when stacking, thereby ensuring the consistency of the finished battery.

[0051] The first slot 121 can be formed on either the inner or outer side of the first fixing structure 12. The inner side of the first fixing structure 12 refers to the side facing the accommodating cavity 105, while the outer side of the first fixing structure 12 refers to the side facing away from the accommodating cavity 105. This embodiment is described using the example of the first slot 121 being formed on the inner side of the first fixing structure 12. That is, the first slot 121 is on the inner side of the first fixing structure 12. The end of the second fixing structure 13 can be inserted into the first slot 121 and abut against the inner wall of the first slot 121. Thus, there is a certain amount of interference between the end of the second fixing structure 13 and the end of the first fixing structure 12. As the first current collector 10 moves as a whole, the second fixing structure 13 moves toward the second current collector 10. The second fixing structure 13 squeezes the first fixing structure 12, causing it to deform, thereby allowing the end of the second fixing structure 13 to slide smoothly into the first slot 121.

[0052] The end of the first fixed structure 12 can be set as an arc-shaped end face. It can be understood that the arc-shaped end face is located at the end of the first fixed structure 12 away from the support structure 11. In this way, the second fixed structure 13 contacts the arc-shaped end face of the first fixed structure 12 during the movement. The arc-shaped end face can decompose the pressure on the first fixed structure 12 during the movement of the second fixed structure 13 into an extrusion force that pushes the first fixed structure 12 to deform inward, which facilitates the sliding of the second fixed structure 13 and plays a centering role. The position of the first current collector 10 is adjusted during the buckling process to avoid jamming when the second fixed structure 13 moves along the first direction.

[0053] In a cross-section along the first direction, the thickness of the first fixing structure 12 decreases and then increases as it moves away from the support structure 11. This means that the first fixing structure 12 has a thinnest point, which facilitates deformation of the end of the first fixing structure 12. Specifically, from the point where the first fixing structure 12 connects to the support structure 11 to the first retaining groove 121, the thickness of the first fixing structure 12 decreases as it moves away from the support structure 11. This means that the thickness of the first fixing structure 12 at the point where it connects to the support structure 11 is greater, increasing the connection area between the first fixing structure 12 and the support structure 11 and improving connection stability.

[0054] The first fixing structure 12 and the second fixing structure 13 have thermal adhesiveness. Specifically, the first fixing structure 12 can be made of a material with thermal adhesiveness. When stacking the current collector 10, the operating environment is a room temperature environment. At this time, the first fixing structure 12 does not have adhesiveness, which is conducive to the stacking of the current collector 10. When the battery cell 103 is assembled and the formation process is completed, the entire battery cell 103 can be heated. At this time, the temperature of the first fixing structure 12 rises until it has adhesiveness, so that the buckling parts of the first fixing structure 12 and the second fixing structure 13 are bonded together. After the battery cell 103 cools to room temperature, the first fixing structure 12 and the second fixing structure 13 are connected into a whole, that is, the first fixing structure 12 and the second fixing structure 13 are snapped together to form a sealing structure for bonding, which has the effect of secondary reinforced sealing and can avoid the fixation failure caused by the loosening of the first fixing structure 12 and the second fixing structure 13 during the subsequent use of the bipolar battery 100.

[0055] In some other embodiments, a thermal adhesive layer may be provided on the outside of the first fixed structure 12 . The thermal adhesive layer is a film made of a thermal adhesive material. The thermal adhesive layer is provided at least on the portion of the first fixed structure 12 that is in contact with the second fixed structure 13 .

[0056] The thermal adhesive material can be selected from commonly used thermal adhesive materials in the art. In addition to an olefin polymer containing glycidyl (meth)acrylate units, the thermal adhesive material may also contain other resins, curing agents, catalysts, and the like. Examples include epoxy resins, phenolic resins, polyurethane resins, acrylic resins, and silicone resins. This disclosure does not limit the thermal adhesive material, as long as it is electrically insulating and has adhesive properties at temperatures between 100°C and 250°C.

[0057] It can be understood that the above description of the positions of the first fixed structure 12 and the second fixed structure 13 on the current collector 10 is only for convenience of description. That is to say, in actual application, the first fixed structure 12 can also be set on the side of the positive electrode material layer 40 of the support structure 11, and the second fixed structure 13 can be set on the side of the negative electrode material layer 60 of the support structure 11.

[0058] The first fixing structure 12 and the second fixing structure 13 can also meet the above conditions simultaneously. Specifically, the first fixing structure 12 is bent to form a first slot 121, with the notch of the first slot 121 facing inward; the second fixing structure 13 is bent to form a second slot 131, with the notch of the second slot 131 facing outward. In the two stacked current collectors 10, the end of the second fixing structure 13 of the first current collector 10 is inserted into the first slot 121 of the first fixing structure 12 of the second current collector 10, and the end of the first fixing structure 12 of the second current collector 10 is inserted into the second slot 131 of the second fixing structure 13 of the first current collector 10, thereby forming a secondary sealing structure, further improving the sealing performance. In addition, the joint between the first fixing structure 12 and the second fixing structure 13 forms a continuously bent S-shaped sealing surface to increase the overlapping portion of the first fixing structure 12 and the second fixing structure 13, provide a sealing surface of sufficient length, and improve sealing reliability.

[0059] In this embodiment, the first fixing structure 12 and the second fixing structure 13 can be an integrally formed bent structure, thereby forming a first engaging groove 121 in the bent portion of the first fixing structure 12, and forming a second engaging groove 131 in the bent portion of the second fixing structure 13. In other embodiments, the first engaging groove 121 can be formed in the first fixing structure 12, and the second engaging groove 131 can be formed in the second fixing structure 13 by machining. This disclosure does not limit the formation method of the first engaging groove 121 and the second engaging groove 131.

[0060] In some embodiments, at least the portion of the support layer 111 exposed from the metal foil 112 is insulating, and the first and second fixing structures 12, 13 are disposed on the insulating portion of the support layer 111. Specifically, the portion of the support layer 111 used to mount the first and second fixing structures 12, 13 is made of an insulating material. This prevents short circuits at the edges of the current collector 10, facilitates the packaging process of the bipolar battery 100, and increases battery safety under high voltage conditions. Furthermore, the first and second fixing structures 12, 13 are also made of an insulating material. The use of an insulating material on the portion of the support layer 111 used to mount the first and second fixing structures 12, 13 enhances the adhesion between the first and second fixing structures 12, 13, and the support layer 111.

[0061] The support layer 111 may be made of insulating materials commonly used in the art, such as at least one of polyethylene terephthalate (PET), polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, and polyimide.

[0062] The area of ​​support layer 111 covered by current collecting layer 113 is at least partially conductive, enabling current collector 10 to better transport collected electrons in the battery. The portion of support layer 111 corresponding to current collecting layer 113 can be filled with conductive particles, which interact with current collecting layer 113 on both sides of support layer 111 to ensure the conductivity of current collector 10.

[0063] In other embodiments, the portion of the support layer 111 corresponding to the current collector layer 113 is a porous thermoplastic elastomer layer. Specifically, the material of the support layer 111 can be the same as that of the separator 50, which ensures that the current collector 10 has a certain strength to meet battery production requirements while also ensuring normal penetration of metal ions.

[0064] The metal foil 112 can be bonded to a preset position on the support layer 111, or can be formed on the surface of the support layer 111 by vacuum distillation of chemical vapor deposition or vacuum distillation of physical vapor deposition. Depending on the type of bipolar battery 100, the material of the metal foil 112 can be copper, aluminum, a metal oxide, or a polymer filled with conductive particles. For example, when the bipolar battery 100 is a lithium-ion battery, the metal foil 112 connecting the support layer 111 and the negative electrode material layer 60 can be copper, and the metal foil 112 connecting the support layer 111 and the positive electrode material layer 40 can be aluminum. When the bipolar battery 100 is a sodium-ion battery, the metal foil 112 on both sides of the support layer 111 can be aluminum.

[0065] As shown in Figure 1, a third fixing structure 21 is provided at the bottom of the positive electrode plate 20. One end of the positive electrode plate 20 extends outward from the housing 101. The portion of the positive electrode plate 20 extending out of the housing 101 forms a positive electrode lead-out portion 22. The third fixing structure 21 can engage with the first fixing structure 12 of the current collector 10 located on the top layer, forming a receiving cavity 105 between the positive electrode plate 20 and the support structure 11 on the top layer.

[0066] Similar to the structure of the positive electrode plate 20, as shown in Figure 1, a fourth fixing structure 31 is provided on the top of the negative electrode plate 30. One end of the negative electrode plate 30 extends outward from the housing 101, and the portion of the negative electrode plate 30 extending out of the housing 101 forms a negative electrode lead-out portion 32. The fourth fixing structure 31 can engage with the second fixing structure 13 of the current collector 10 located at the bottom layer, forming a receiving cavity 105 between the negative electrode plate 30 and the bottom support structure 11.

[0067] By providing a third fixing structure 21 on the positive electrode plate 20 and a fourth fixing structure 31 on the negative electrode plate 30, a sealed space is formed where all the positive electrode material layers 40, the separator 50, and the negative electrode material layers 60 are located, separating the paired positive / negative electrode material layers from other structures, thereby reducing the risk of short circuits between different electrodes and improving the sealing and safety of the finished battery. When the bipolar battery 100 is used in a vehicle, the positive electrode lead-out portion 22 and the negative electrode lead-out portion 32 are electrically connected to external electrical appliances. The electrolyte can be a liquid electrolyte, which is filled in the accommodating cavity 105. The structure formed by the first fixing structure 12 and the second fixing structure 13 can also reduce the risk of liquid electrolyte leakage.

[0068] In other embodiments, the electrolyte may also be a solid electrolyte, which is coated on the surface of the diaphragm 50 ; or the diaphragm 50 may be replaced by a solid electrolyte, which is filled between the positive electrode material layer 40 and the negative electrode material layer 60 .

[0069] The third fixing structure 21 can have the same specifications as the first fixing structure 12, and the fourth fixing structure 31 can have the same specifications as the second fixing structure 13. Specification consistency can be understood as consistency in parameters such as material, shape, and size. Therefore, this disclosure will not further describe the third fixing structure 21 and the fourth fixing structure 31 in detail.

[0070] The process flow of the bipolar battery 100 is as follows, please refer to FIG. 5 .

[0071] In the first step, positive and negative electrode materials are coated on the front and back surfaces of the current collector 10, forming a positive electrode material layer 40 and a negative electrode material layer 60. Specifically, the positive electrode material layer 40 and the negative electrode material layer 60 are coated on the metal foil 112. Next, a separator 50 coated with a solid electrolyte is applied to the negative electrode material layer 60 of the current collector 10. The projection of the separator 50 along the stacking direction at least completely covers the projections of the positive electrode material layer 40 and the negative electrode material layer 60 along the stacking direction. Specifically, the separator 50 can completely separate the positive electrode material layer 40 and the negative electrode material layer 60, preventing internal short circuits between the positive electrode material layer 40 and the negative electrode material layer 60. At this point, the separator 50, the negative electrode material layer 60, the current collector 10, and the positive electrode material layer 40 form a bipolar unit.

[0072] In the second step, a negative electrode material layer 60 covered with a separator 50 is first placed on the negative electrode plate 30 and used as a base; then n bipolar units (n≥2) are stacked in sequence on the separator 50; then the positive electrode material layer 40 is covered on the top separator 50 as the outermost layer; finally, the outermost layer is covered with the positive electrode plate 20.

[0073] In the third step, the entire battery cell 103 is wrapped and sealed with an outer packaging film (housing 101 ), and the portion of the positive electrode plate 20 extending out of the housing 101 is used as the positive electrode lead-out portion 22 .

[0074] For example, the solid electrolyte-coated separator 50 may be a conventional separator, a solid electrolyte, or the like.

[0075] When a liquid electrolyte is selected as the electrolyte, the step of covering the diaphragm 50 coated with a solid electrolyte on the negative electrode material layer 60 of the current collector 10 is replaced by: after covering the diaphragm 50 on the negative electrode material layer 60 of the current collector 10, injecting a liquid electrolyte between the diaphragm 50 and the support structure 11.

[0076] During the stacking process, the second fixed structure 13 of the first current collector can be engaged with the first fixed structure 12 of the second current collector, so that the first fixed structure 12 and the second fixed structure 13 are used to form a accommodating cavity 105 between the supporting structure 11 of the first fixed structure 12 and the supporting structure 11 of the second fixed structure 13, and the positive electrode material layer 40, the diaphragm 50 and the negative electrode material layer 60 arranged in the accommodating cavity 105 are preliminarily sealed, thereby reducing the risk of leakage of the liquid electrolyte in the accommodating cavity 105 and improving the sealing and safety of the finished battery.

[0077] After the current collector 10, positive electrode plate 20, negative electrode plate 30, positive electrode material layer 40, negative electrode material layer 60, and separator 50 are stacked in a certain order to form a battery cell 103, charging and discharging are performed to complete the formation process. During the formation process, the battery will produce gas, increasing the internal pressure.

[0078] In the present disclosure, at least one of the first fixed structure 12 and the second fixed structure 13 is an elastic structure. This embodiment is described with the first fixed structure 12 as an elastic structure. During the stacking process, after each layer of current collector 10 is stacked, a certain force will be applied along the first direction to maintain the mutual engagement of the sealing structure, and the rebound force of the positive electrode material layer 40, the negative electrode material layer 60 and the diaphragm 50 and the external restraining force are used to balance to achieve the purpose of fastening. In the formation process, please refer to Figure 6. After the battery produces gas, the external restraining force is adjusted, and the internal air pressure is used to lift the second fixed structure 13 relative to the first fixed structure 12 and form a gap. When the gap becomes larger, its force area gradually increases. Finally, when the effect of the internal air pressure exceeds the deformation of the first fixed structure 12 and the effect of the external restraining force, a channel is opened between the first fixed structure 12 and the second fixed structure 13, thereby smoothly achieving exhaust.

[0079] In practical applications, the second fixing structure 13 may be elastic, or both the first fixing structure 12 and the second fixing structure 13 may be elastic.

[0080] After the formation process is completed, the battery core 103 is heated so that the first fixing structure 12 and the second fixing structure 13 are bonded together to form a whole. Finally, the housing 101 is used to wrap and seal the entire battery core 103 .

[0081] For the finished bipolar battery 100, by setting a first fixing structure 12 and a second fixing structure 13 on both sides of the support structure 11 of the current collector 10, the current collector 10 can be made into a standard structure. When the current collector 10 is stacked, the first fixing structure 12 and the second fixing structure 13 cooperate to automatically achieve positioning and fastening, without the need to additionally control the position of the current collectors 10 of the two adjacent layers. Based on the structure of the current collector 10, the present disclosure makes adaptive adjustments to the structures of the positive plate 20 and the negative plate 30. A third fixing structure 21 is set on the positive plate 20 to cooperate with the first fixing structure 12 of the current collector 10, and a fourth fixing structure 31 is set on the negative plate 30 to cooperate with the second fixing structure 13 of the current collector 10. During the stacking process, the negative plate 30, the current collector 10 and the positive plate 20 can be pre-assembled together and connected by snap-fitting, reducing the displacement between the negative plate 30, the current collector 10 and the positive plate 20, thereby improving the consistency of the finished product and reducing production and processing costs.

[0082] The bipolar battery 100 provided in the second embodiment of the present disclosure has a substantially similar structure to the bipolar battery 100 provided in the first embodiment, except that, in two adjacent current collectors 10 of the bipolar battery 100 , the first fixing structure 12 of one current collector 10 is adhered to the second fixing structure 13 of the other current collector 10 to seal the accommodating cavity 105 .

[0083] In this embodiment, after the formation process is completed, the battery cell 103 is heated so that the first fixing structure 12 and the second fixing structure 13 are bonded at the fastening point to form a whole. At this time, the accommodating cavity 105 is a accommodating cavity, thereby avoiding leakage of the electrolyte in the accommodating cavity 105 during the use of the bipolar battery 100, reducing the short circuit between the positive electrode material layer 40 and the negative electrode material layer 60 in different accommodating cavities 105, and improving the sealing and safety of the finished bipolar battery 100.

[0084] It is understood that during the hot pressing process, the first fixed structure 12 and the second fixed structure 13 may adhere to each other, and the hot pressing process may cause the shape of the first fixed structure 12 and / or the second fixed structure 13 to change. The above description of the shape of the first fixed structure 12 and the second fixed structure 13 applies to the first fixed structure 12 and the second fixed structure 13 before hot pressing. After hot pressing, there is no longer any restriction on the shape of the first fixed structure 12 and the second fixed structure 13. It is only necessary to ensure that the first fixed structure 12 and the second fixed structure 13 are adhered together to form an integral structure, and that the first fixed structure 12, the second fixed structure 13 and the two adjacent support structures 11 together form a sealed accommodating cavity 105.

[0085] The present disclosure also provides an electric device 200, including a bipolar battery 100, as shown in FIG7 . The bipolar battery 100 is used to supply power to the electric device 200. The electric device 200 may be a vehicle. It should be understood that the present disclosure is not limited to the use of the bipolar battery 100 in vehicles; the bipolar battery 100 may also be used in other fields, such as power equipment, communications equipment, medical equipment, industrial automation equipment, and the like.

[0086] The above are some implementation methods of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present disclosure. These improvements and modifications are also considered to be within the scope of protection of the present disclosure.

Claims

1. A current collector (10), characterized in that: The current collector (10) comprises: Support structure (11); a first fixed structure (12); and The second fixing structure (13), the first fixing structure (12) and the second fixing structure (13) are respectively arranged on opposite sides of the support structure (11); when at least two current collectors (10) are stacked, the first fixing structure (12) of one current collector (10) and the second fixing structure (13) of the other current collector (10) of two adjacent current collectors (10) are detachably connected, so that the two adjacent support structures (11) and the first fixing structure (12) and the second fixing structure (13) that are detachably connected to each other jointly form a receiving cavity (105), and the receiving cavity (105) is used to receive an electrolyte.

2. The current collector (10) according to claim 1, characterized in that The first fixing structure (12) and the second fixing structure (13) are both snap-fit structures; in two adjacent current collectors (10), the first fixing structure (12) of one current collector (10) is snap-fitted to the second fixing structure (13) of the other current collector (10).

3. The current collector (10) according to claim 2, characterized in that The first fixing structure (12) is provided with a first clamping groove (121), and the first clamping groove (121) is used to clamp the second fixing structure (13) on the adjacent current collector (10) when at least two current collectors (10) are stacked.

4. The current collector (10) according to claim 3, characterized in that The second fixing structure (13) is provided with a second card groove (131). When at least two current collectors (10) are stacked, in the first fixing structure (12) and the second fixing structure (13) that are engaged with each other, the end of the first fixing structure (12) is engaged with the second card groove (131) of the second fixing structure (13), and the end of the second fixing structure (13) is engaged with the first card groove (121) of the first fixing structure (12), so as to form a continuously bent fitting surface between the first fixing structure (12) and the second fixing structure (13).

5. The current collector (10) according to claim 4, characterized in that The first fixing structure (12) is bent to form the first clamping slot (121), and the second fixing structure (13) is bent to form the second clamping slot (131).

6. The current collector (10) according to any one of claims 2 to 5, characterized in that: The end of the first fixing structure (12) and the end of the second fixing structure (13) are arc-shaped.

7. The current collector (10) according to any one of claims 1 to 6, characterized in that At least one of the first fixing structure (12) and the second fixing structure (13) has thermal adhesiveness.

8. The current collector (10) according to any one of claims 1 to 7, characterized in that The support structure (11) has current collecting layers (113) on both opposite sides, and the first fixing structure (12) and the second fixing structure (13) are arranged on the periphery of the current collecting layer (113) on the same side.

9. The current collector (10) according to claim 8, characterized in that The support structure (11) comprises a support layer (111) and two metal foils (112), wherein the two metal foils (112) are respectively arranged on opposite sides of the support layer (111) to form the current collecting layer (113).

10. The current collector (10) according to claim 9, characterized in that At least the portion of the support layer (111) exposed to the metal foil (112) is insulating, and the first fixing structure (12) and the second fixing structure (13) are arranged on the insulating portion of the support layer (111).

11. The current collector (10) according to claim 9 or 10, characterized in that The area of the support layer (111) covered by the current collecting layer (113) is at least partially conductive.

12. A bipolar battery (100), characterized in that: The bipolar battery (100) comprises: Positive plate (20); a negative plate (30); and A plurality of current collectors (10) according to any one of claims 1 to 11, wherein the plurality of current collectors (10) are stacked between the positive electrode plate (20) and the negative electrode plate (30), and are stacked in a direction from the positive electrode plate (20) toward the negative electrode plate (30).

13. The bipolar battery (100) according to claim 12, characterized in that A third fixing structure (21) is provided on a side of the positive electrode plate (20) facing the current collector (10), and the third fixing structure (21) of the positive electrode plate (20) is engaged with the first fixing structure (12) of the adjacent current collector (10) to form a receiving cavity (105) between the positive electrode plate (20) and the supporting structure (11) of the adjacent current collector (10); A fourth fixing structure (31) is provided on the side of the negative electrode plate (30) facing the current collector (10), and the fourth fixing structure (31) of the negative electrode plate (30) is engaged with the second fixing structure (13) of the adjacent current collector (10) to form a receiving cavity (105) between the negative electrode plate (30) and the supporting structure (11) of the adjacent current collector (10).

14. The bipolar battery (100) according to claim 13, characterized in that Along the direction from the positive electrode plate (20) toward the negative electrode plate (30), a positive electrode material layer (40), a separator (50) and a negative electrode material layer (60) are sequentially stacked in the accommodating cavity (105); the positive electrode material layer (40) is provided on the positive electrode plate (20) or the current collector (10), and the negative electrode material layer (60) is provided on the negative electrode plate (30) or the current collector (10).

15. The bipolar battery (100) according to claim 14, characterized in that The projection of the separator (50) along the stacking direction at least completely covers the projection of the positive electrode material layer (40) along the stacking direction and the projection of the negative electrode material layer (60) along the stacking direction.

16. The bipolar battery (100) according to claim 14 or 15, characterized in that: The diaphragm (50) is coated with a solid electrolyte; or the accommodating cavity (105) is filled with a liquid electrolyte.

17. The bipolar battery (100) according to any one of claims 14 to 16, characterized in that: The bipolar battery (100) further comprises a housing (101), wherein the current collector (10), the positive electrode material layer (40), the separator (50) and the negative electrode material layer (60) are all arranged in the housing (101), a portion of the positive electrode plate (20) extends out of the housing (101) to form a positive electrode lead-out portion (22), and a portion of the negative electrode plate (30) extends out of the housing (101) to form a negative electrode lead-out portion (32).

18. A bipolar battery (100), characterized in that: The bipolar battery (100) comprises: Positive plate (20); a negative plate (30); and A plurality of current collectors (10) according to any one of claims 1 to 11, wherein the plurality of current collectors (10) are stacked between the positive electrode plate (20) and the negative electrode plate (30), and are stacked in a direction from the positive electrode plate (20) toward the negative electrode plate (30), and in two adjacent current collectors (10), the first fixing structure (12) of one current collector (10) is adhered to the second fixing structure (13) of the other current collector (10) to seal the accommodating cavity (105).

19. The bipolar battery (100) according to claim 18, characterized in that A third fixing structure (21) is provided on a side of the positive electrode plate (20) facing the current collector (10), and the third fixing structure (21) of the positive electrode plate (20) is adhered to the first fixing structure (12) of the adjacent current collector (10) to form a receiving cavity (105) between the positive electrode plate (20) and the supporting structure (11) of the adjacent current collector (10); A fourth fixing structure (31) is provided on the side of the negative electrode plate (30) facing the current collector (10), and the fourth fixing structure (31) of the negative electrode plate (30) is adhered to the second fixing structure (13) of the adjacent current collector (10) to seal the accommodating cavity (105), so as to form an accommodating cavity (105) between the negative electrode plate (30) and the supporting structure (11) of the adjacent current collector (10).

20. An electrical device (200), characterized in that: The electric device (200) comprises the bipolar battery (100) according to any one of claims 12 to 17 or 18 to 19.

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