Battery structure and battery module
Technical Field
The invention belongs to the technical field of battery production and manufacturing, and particularly relates to a battery structure and a battery module.
Background
Nowadays, lithium ion batteries have the characteristics of high energy density, long cycle life, low self-discharge, environmental friendliness and the like. With the vigorous popularization of the pure electric vehicles in China, the application of the lithium ion battery in the pure electric vehicles is also increased explosively. In order to promote the rapid development of the related industries of power batteries and achieve curve overtaking in the automobile industry, the state has come out of the relevant subsidy policy of the new energy industry, wherein the important goal of the subsidy policy is to continuously guide and improve the energy density of a battery system. At present, the energy density of a power battery system is improved mainly by improving the energy density of a power battery cell, but before a positive electrode material and a negative electrode material of the power battery obtain no major breakthrough, the improving range of the energy density of the battery cell is very limited. Considering that the battery cell is a component of the battery system, the improvement of the energy density cannot consider the battery cell on one side, and the battery cell is considered comprehensively from the battery system level. How well the cell size fits the battery system size is also an effective way to increase the cell system energy density. Consequently reasonable increase electric core thickness, length, highly can improve electric core energy density to a certain extent, but increase electric core thickness and be unfavorable for electric core heat dissipation, influence electric core performance, and electric core height is subject to the height of battery package system, and increase electric core length and be favorable to electric core heat dissipation, can also promote electric core energy density.
When electric core length increases to certain extent, electric core manufacturing process will be difficult to realize, consequently form a longer naked electric core through the mode combination of establishing ties with a plurality of naked electric cores together, encapsulate it in corresponding container again, this method realizes batch manufacturing more easily
However, the inventor finds that the existing scheme has at least the following defects: the battery pack is connected in a series mode, the voltage of the battery can be increased along with the number of the electric cores in the battery, so that the voltages at two ends of the battery are higher, the electrolyte in the battery has decomposition risk, and the performance of the electric cores can be influenced or even the safety of the battery can be caused.
Disclosure of Invention
One of the objects of the present invention is: to prior art's not enough, provide a battery structure, can avoid the electrolyte circulation between the group battery, solve the higher inside electrolyte that leads to the battery of battery both ends voltage and have the problem of decomposition, help improving the performance of battery.
In order to achieve the purpose, the invention adopts the following technical scheme:
the utility model provides a battery structure, includes the casing that a plurality of both ends switched on, and is adjacent be fixed with electrically conductive connecting piece between the casing, the casing with the connecting piece encloses into a plurality of and is used for the sealed chamber of holding electric core, and is adjacent pass through between the electric core the connecting piece electricity is connected.
As an improvement of the battery structure of the present invention, the connecting member includes a body and connecting portions disposed at two sides of the body, wherein a tab is formed at a side portion of the battery cell corresponding to the connecting portion, and the tab is electrically connected to the connecting portion.
As an improvement of the battery structure of the present invention, the connecting portion includes a first connecting portion and a second connecting portion, and the first connecting portion and the second connecting portion are respectively connected to the tabs of the adjacent battery cells.
As an improvement of the battery structure of the present invention, the first connecting portion and the second connecting portion are disposed at two sides of the body in a staggered manner, and correspondingly, the tabs at two sides of the battery cell are disposed in a staggered manner.
As an improvement of the battery structure of the present invention, the housing and the connecting member are fixedly connected by welding, and the body and the connecting member are fixedly connected by welding.
As an improvement of the battery structure of the present invention, the material of the connecting portion is the same as the current collecting material of the pole piece of the battery cell electrically connected thereto.
As an improvement of the battery structure of the present invention, the two ends of the housing are respectively provided with an opening, the openings of the adjacent housings are sequentially and correspondingly arranged, and the connecting member is arranged between the two openings.
As an improvement of the battery structure, the shell is provided with at least one of a liquid injection hole and an explosion-proof valve which are communicated with the sealing cavity, insulating sheets are arranged below the liquid injection hole and the explosion-proof valve, and the insulating sheets are provided with hollow structures.
As an improvement of the battery structure, at least one of a pole column, a liquid injection hole and an explosion-proof valve is arranged on the outer side of the connecting piece at the head end and the tail end of the battery structure.
The present invention also provides a battery module including the above battery structure.
The battery cell structure has the beneficial effects that the battery cell structure comprises a plurality of shells with two communicated ends, conductive connecting pieces are fixed between the adjacent shells, a plurality of sealing cavities for containing battery cells are defined by the shells and the connecting pieces, and the adjacent battery cells are electrically connected through the connecting pieces. Because the battery pack is connected in series, the voltage of the battery is higher along with the increase of the number of electric cores in the battery, the voltages at two ends of the battery are higher, the electrolyte in the battery is decomposed, the performance of the electric cores can be influenced, and even the safety problem of the battery can be caused, therefore, a conductive connecting piece is fixed between the adjacent shells, the connecting piece is of a metal plate structure and is fixed at two ends of the shell by welding, compared with an insulating plate, the connecting piece is fixed between the adjacent shells, the shells and the connecting piece are made of metal materials, the mechanical strength of the shell and the connecting piece after welding is higher, namely, the stability between the shell and the connecting piece is better, meanwhile, the connecting piece is not easy to shift or generate a gap after being pressed by adopting a welding fixing; one surface of the connecting piece positioned on the two end surfaces of the battery is connected with the battery core, and the other surface is provided with a positive output electrode or a negative pole which is convenient for charging and discharging the battery or is connected with other battery structures in series or in parallel, wherein the shell is a hollow structure, the connecting pieces are made of metal materials, the two connecting pieces are respectively fixed at the openings at the two sides of the shell, the connecting piece is shared between the two adjacent shells, namely, one side of the connecting piece is fixed on one shell and is electrically connected with the battery core in the shell, the other side of the connecting piece is fixed on the other shell, and is electrically connected with the battery cells in the shell, thereby realizing the series connection among a plurality of battery cells, because the connecting piece has electric conductivity, a conductive connecting hole is not arranged in the connecting piece, the sealing property of the sealing cavity is improved, and the electrolyte is prevented from forming an ion path between the cavities of the shells. The casing that a plurality of both ends switched on passes through the connecting piece and forms a plurality of sealed chamber, and sealed chamber can prevent that electrolyte from forming ion channel between each casing cavity, and in addition, sealed chamber plays the effect of keeping apart each electric core, can take place when thermal runaway at the electric core of one of them sealed intracavity, can not spread other sealed chambers immediately, prevents that the electric core of other sealed intracavity from receiving the influence, helps reducing the inside probability that takes place the short circuit of battery. The invention can avoid the circulation of electrolyte between the battery packs, solve the problem of decomposition of the electrolyte in the battery caused by higher voltage at two ends of the battery, and is beneficial to improving the performance of the battery.
Drawings
Fig. 1 is a schematic structural diagram of a first embodiment of the present invention.
Fig. 2 is an exploded view of a first embodiment of the present invention.
Fig. 3 is a schematic structural diagram of a second embodiment of the present invention.
Fig. 4 is an exploded view of a second embodiment of the present invention.
Fig. 5 is a schematic structural view of a battery end connector according to a second embodiment of the present invention.
Wherein: 1-a shell; 2-a connector; 3-electric core; 21-body; 22-a connecting part; 221-a first connection; 222-a second connection; 31-a tab; 4-liquid injection hole; 5-explosion-proof valve and 6-pole.
Detailed Description
As used in the specification and in the claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", horizontal ", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The present invention will be described in further detail with reference to fig. 1 to 5, but the present invention is not limited thereto.
Implementation mode one
The utility model provides a battery structure, includes casing 1 that a plurality of both ends switched on, is fixed with electrically conductive connecting piece 2 between the adjacent casing 1, and casing 1 and connecting piece 2 enclose into a plurality of and are used for the sealed chamber of holding electric core 3, connect through connecting piece 2 electricity between the adjacent electric core 3. Because the battery pack is connected in series, the voltage of the battery is higher along with the increase of the number of electric cores in the battery, so that the voltages at two ends of the battery are higher, the electrolyte in the battery is at risk of decomposition, the performance of the electric cores is influenced, and even the safety problem of the battery is caused, as shown in fig. 1-2, therefore, a conductive connecting piece 2 is fixed between adjacent shells 1, the connecting piece 2 is in a metal plate structure and is fixed at two ends of the shell 1 by welding, compared with an insulating plate, the shell 1 and the connecting piece 2 are both made of metal materials, the mechanical strength of the shell 1 and the connecting piece 2 after welding is higher, namely, the stability between the shell 1 and the connecting piece 2 is better, and meanwhile, the connecting piece 2 is not easy to shift or generate a gap after being pressed by adopting a welding fixing mode, and the sealing; one side of the connecting pieces 2 positioned at two end faces of the battery is connected with the battery core 3, the other side is provided with a positive output electrode or a negative electrode post 6, which is convenient for charging and discharging the battery, or is connected with other battery structures in series or in parallel, wherein, the shell 1 is a hollow structure, the connecting pieces 2 are made of metal materials, the two connecting pieces 2 are respectively fixed at the openings at two sides of the shell 1, the connecting pieces 2 are shared between two adjacent shells 1, namely, one side of the connecting piece 2 is fixed at one of the shells 1 and is electrically connected with the battery core 3 in the shell 1, the other side of the connecting piece 2 is fixed at the other shell 1 and is electrically connected with the battery core 3 in the shell 1, thereby realizing the series connection among a plurality of battery cores 3, in addition, because the connecting piece 2 has electric conductivity, the conductive connecting hole arranged in the connecting piece 2 is omitted, the electrolyte is prevented from forming an ion path between the chambers of the housing 1. Casing 1 that a plurality of both ends switched on forms a plurality of sealed chamber through connecting piece 2, and the sealed chamber can prevent that electrolyte from forming ion channel between 1 cavity of each casing, and in addition, the sealed chamber plays the effect of keeping apart each electric core 3, can take place when thermal runaway at electric core 3 of one of them sealed intracavity, can not spread other sealed chambers immediately, prevents that electric core 3 of other sealed intracavity from receiving the influence, helps reducing the inside probability that takes place the short circuit of battery.
In the present embodiment, the battery cells 3 include but are not limited to a winding structure or a lamination structure, the number of the battery cells 3 can be adjusted according to the length of the actual battery, the number of the battery cells can be limited to 1-50, which prevents the battery cells from being too large, which results in an excessively long battery, increases the transportation cost of the battery, in order to avoid short circuit of the positive and negative poles 6, the negative pole 6 is connected to the housing 1 in an insulated manner, including but not limited to providing an insulating part between the connecting member 2 and the housing 1 at both end surfaces of the battery, or the negative pole 6 is connected to the connecting member 2 in an insulated manner, i.e. providing an insulating plastic between the negative pole 6 and the body 21 of the connecting member 2, and providing a through hole for the negative pole 6 in the body 21, so that the negative pole 6 is directly electrically connected to the connecting part 22, and further, the short circuit of the positive and negative poles 6 can be avoided.
Preferably, the connector 2 includes a body 21 and connecting portions 22 disposed at two sides of the body 21, wherein tabs 31 are formed at side portions of the battery cell 3 corresponding to the connecting portions 22, and the tabs 31 are electrically connected to the connecting portions 22. Connecting portion 22 is fixed on the surface of body 21, and connecting portion 22 includes but not limited to the setting of vertical fixation in body 21, also can parallel fixation in body 21, and it can to satisfy the fixed connection between body 21 and the connecting portion 22, and utmost point ear 31 of electric core 3 is connected with connecting portion 22 electricity, realizes electric connection of electric core 3 and connecting piece 2, and is corresponding, and adjacent electric core 3 also is connected with connecting piece 2 electricity to realize the electric connection between two electric cores 3.
Preferably, the connection portion 22 includes a first connection portion 221 and a second connection portion 222, and the first connection portion 221 and the second connection portion 222 connect the tabs 31 of the adjacent battery cells 3, respectively. The connecting portion 22 is divided into a first connecting portion 221 and a second connecting portion 222, and is disposed on two sides of the body 21 and respectively corresponding to the positive electrode tab 31 and the negative electrode tab 31 of the adjacent electric core 3, in addition, two end surfaces of the battery are sealed by the connecting member 2, the first connecting portion 221 or the second connecting portion 222 is disposed on one surface of the connecting member 2, and the positive electrode output electrode or the negative electrode tab 6 is disposed on the other surface of the connecting member 2, so as to facilitate charging and discharging of the battery, or to be connected in series or in parallel with other battery structures.
Preferably, the housing 1 and the connecting member 2 are fixedly connected by welding, and the body 21 and the connecting portion 22 are fixedly connected by welding. In the embodiment, the shell 1 and the connecting piece 2 are sealed by laser welding, which is beneficial to improving the sealing performance of the sealing cavity, and in the collision or oscillation process of the battery, the connecting piece 2 is not easy to shift or fall off from the shell 1, so that the electrolyte is prevented from forming an ion path between the cavities of the shell 1 through a gap, the stability of the whole battery is improved, and the safety of the battery is improved; the body 21 and the connecting portion 22 are fixedly connected by welding, which helps to improve the stability between the body 21 and the connecting portion 22 and prevent the connecting portion 22 from falling off to cause short circuit of the battery, and in addition, the connecting portion 22 and the tab 31, including but not limited to ultrasonic welding, helps to improve the stability between the connecting portion 22 and the tab 31 and prevents the connecting portion 22 from falling off to cause short circuit of the battery.
Preferably, the case 1 is provided with at least one of a liquid injection hole 4 and an explosion-proof valve 5 communicating with the sealed chamber. The electrolyte injection hole 4 is convenient for injecting electrolyte into the battery; the explosion-proof valve 5 can automatically and rapidly release the pressure of the battery when the battery rises due to overcharge, overdischarge, overcurrent and short circuit inside the battery, so that safety accidents caused by battery explosion are avoided. In the embodiment, the liquid injection hole 4 and the explosion-proof valve 5 are arranged at the top of each shell 1, so that each sealed cavity is ensured to be injected independently, and the situation that the electrolyte inside the battery is not distributed uniformly due to the overlong battery cell is avoided.
The working principle of the invention is as follows:
because the battery pack is connected in series, the voltage of the battery is higher at two ends of the battery along with the increase of the number of the electric cores in the battery, the decomposition risk of electrolyte in the battery exists, the performance of the electric cores can be influenced, and even the safety problem of the battery can be caused, therefore, a plurality of shells 1 with two ends conducted form a plurality of sealing cavities through connecting pieces 2, the sealing cavities can prevent the electrolyte from forming ion channels between cavities of the shells 1, and the sealing cavities play a role in isolating the electric cores 3, when the electric core 3 in one sealing cavity is out of control due to heat, the electrolyte cannot be instantly diffused to other sealing cavities, the electric cores 3 in other sealing cavities are prevented from being influenced, and the probability of short circuit in the battery is favorably reduced; the adjacent shells 1 are fixedly connected through the connecting pieces 2, so that the shells 1 form a sealed cavity, the connecting pieces 2 block the flow of electrolyte in the adjacent shells 1, the electrolyte in the shells 1 cannot influence each other, and cannot be decomposed due to overlarge potential, and the safety and the service life of the battery are improved; one side of the connecting pieces 2 positioned at two end faces of the battery is connected with the battery core 3, the other side is provided with a positive output electrode or a negative electrode post 6, which is convenient for charging and discharging the battery, or is connected with other battery structures in series or in parallel, wherein, the shell 1 is a hollow structure, the connecting pieces 2 are made of metal materials, the two connecting pieces 2 are respectively fixed at the openings at two sides of the shell 1, the connecting pieces 2 are shared between two adjacent shells 1, namely, one side of the connecting piece 2 is fixed at one of the shells 1 and is electrically connected with the battery core 3 in the shell 1, the other side of the connecting piece 2 is fixed at the other shell 1 and is electrically connected with the battery core 3 in the shell 1, thereby realizing the series connection among a plurality of battery cores 3, in addition, because the connecting piece 2 has electric conductivity, the conductive connecting hole arranged in the connecting piece 2 is omitted, the electrolyte is prevented from forming an ion path between the chambers of the housing 1.
Second embodiment
As shown in fig. 3 to 5, the first embodiment is different from the first embodiment: the first connection portion 221 and the second connection portion 222 of the present embodiment are disposed on two sides of the body 21 in a staggered manner, correspondingly, the tabs 31 on two sides of the battery cell 3 are disposed in a staggered manner, and at least one of the terminal post 6, the liquid injection hole 4 and the explosion-proof valve 5 is disposed on the outer side of the connection member 2 at the head end and the tail end of the battery structure. The first connecting portion 221 and the second connecting portion 222 are arranged on two sides of the body 21 in a staggered manner, so that the first connecting portion 221 and the second connecting portion 222 can be prevented from being excessively stressed and concentrated at the same position, and the service life of the connecting portion 22 is prolonged; the connecting pieces 2 at the head end and the tail end of the battery structure are provided with at least one of the pole posts 6, the liquid injection holes 4 and the explosion-proof valves 5, so that the liquid injection holes 4 or the explosion-proof valves 5 are omitted from the top of the shell 1, meanwhile, the pole posts 6 and the liquid injection holes 4 can be increased or the explosion-proof valves 5 can be reduced by replacing the connecting pieces 2 according to actual needs, the flexibility of the battery is improved, and the production cost of the battery is reduced; in order to avoid the short circuit of the positive and negative pole posts 6, the post 6 on one of the connecting pieces 2 is connected with the casing 1 in an insulating way, including but not limited to the insulating part arranged between the connecting piece 2 positioned on the two end faces of the battery and the casing 1, and the post 6 can also be connected with the connecting piece 2 in an insulating way, namely, insulating plastic is arranged between the post 6 and the body 21 of the connecting piece 2, and a through hole of the post 6 is arranged on the body 21, so that the post 6 is directly electrically connected with the connecting part 22.
Other structures are the same as those of the first embodiment, and are not described herein again.
Third embodiment
The difference from the first embodiment is that: the material of connecting portion 22 of this embodiment is the same with the mass flow material of the pole piece of electric core 3 of its electricity connection, and 1 both ends of casing all are provided with the opening, and adjacent 1's of casing opening corresponds the setting in proper order, and connecting piece 2 sets up between two openings, and the below of annotating liquid hole 4 and explosion-proof valve 5 all is provided with the insulating piece, and the insulating piece is provided with hollow out construction. In the present embodiment, the connection part 22 for connecting the negative electrode tab 31 is made of copper, and the connection part 22 for connecting the positive electrode tab 31 is made of aluminum, thereby ensuring no pressure drop due to material variation and reducing the production cost of the connection part 22; the openings of the adjacent shells 1 are in one-to-one correspondence, the connecting pieces 2 are arranged between the two openings, one side of each connecting piece 2 is fixed to the opening of one shell 1 and is electrically connected with the battery cell 3 in the shell 1, and the other side of each connecting piece 2 is fixed to the opening of the other shell 1 and is electrically connected with the battery cell 3 in the shell 1, so that the series connection among the battery cells 3 is realized; increase the insulating piece, play the effect of protection electricity core 3, prevent to annotate liquid hole 4 and explosion-proof valve 5 and take place the friction with electricity core 3, lead to electric core 3 impaired, the insulating piece is provided with hollow out construction, is convenient for carry out electrolyte injection, when the battery takes place thermal runaway, is convenient for high temperature high pressure gas from explosion-proof valve 5 discharges simultaneously.
Other structures are the same as those of the first embodiment, and are not described herein again.
Embodiment IV
A battery module comprises the battery structure of the first embodiment.
It should be noted that: the shells 1 with two communicated ends form a plurality of sealed cavities through the connecting pieces 2, the sealed cavities can prevent electrolyte from forming an ion channel between the cavities of each shell 1, and the sealed cavities play a role in isolating each cell 3, so that when the cell 3 in one sealed cavity is out of control due to heat, the electrolyte cannot be diffused to other sealed cavities immediately, the cells 3 in other sealed cavities are prevented from being influenced, and the probability of short circuit in the battery is reduced; in addition, because the connecting piece 2 has conductivity, a conductive connecting hole is omitted from being arranged inside the connecting piece 2, the sealing performance of a sealing cavity is improved, and the electrolyte is prevented from forming an ion path between the cavities of the shell 1.
Fifth embodiment
A battery module comprises the battery structure of the second embodiment.
It should be noted that: connecting piece 2 at the head and the tail both ends of battery structure is provided with utmost point post 6, annotates at least one in liquid hole 4 and the explosion-proof valve 5, has saved and has set up at the top of casing 1 and has annotated liquid hole 4 or explosion-proof valve 5, simultaneously, can be according to actual need, through changing connecting piece 2, can realize increasing and annotate liquid hole 4 or reduce explosion-proof valve 5, or increase safety components such as upset piece, help improving the flexibility of battery, help reducing battery manufacturing cost.
Sixth embodiment
A battery module includes the battery structure of the third embodiment.
It should be noted that: the openings of the adjacent shells 1 are in one-to-one correspondence, the connecting pieces 2 are arranged between the two openings, one side of each connecting piece 2 is fixed to the opening of one shell 1 and is electrically connected with the battery cell 3 in the shell 1, and the other side of each connecting piece 2 is fixed to the opening of the other shell 1 and is electrically connected with the battery cell 3 in the shell 1, so that the series connection among the battery cells 3 is realized; increase the insulating piece, play the effect of protection electricity core 3, prevent to annotate liquid hole 4 and explosion-proof valve 5 and take place the friction with electricity core 3, lead to electric core 3 impaired, the insulating piece is provided with hollow out construction, is convenient for carry out electrolyte and pours into, and when the battery took place thermal runaway, the high temperature high pressure gas of being convenient for was discharged from explosion-proof valve 5 simultaneously.
Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.