The present application relates to the field of battery technologies, and in particular to a battery.
Electric energy has become an indispensable energy in daily life in the current society, and more attention has been paid to generation and storage of the electric energy. Especially for the storage of the electric energy, the electric energy that cannot be fully consumed is stored by a battery, and thus continuous supply of the electric energy may be achieved when a failure occurs to an electric power system.
In batteries of the related art, a jelly-roll is usually installed in an accommodating cavity of a housing. However, during installing the jelly-roll in the accommodating cavity of the housing and during moving the battery, the jelly-roll may collide with the housing, resulting in damage to the jelly-roll structure, thereby affecting the stability of the electrical performance of the battery, where the battery may become unusable in severe cases.
Embodiments of the present application disclose a battery in which insulation and anti-collision protection for the jelly-roll are achieved, and service life of the battery is improved.
In order to achieve the above object, the present application discloses a battery, comprising:
a housing having an accommodating cavity having an opening;
a core assembly provided in the accommodating cavity and including a jelly-roll and an insulating sheet covering the jelly-roll, where the jelly-roll has a body portion, and the body portion has a top end surface and a bottom end surface located at both ends of the body portion, and a peripheral surface connected to the top end surface and the bottom end surface, and the insulating sheet covers the peripheral surface and/or the bottom end surface;
a separator provided in the housing and configured to separate the bottom end surface of the jelly-roll from a bottom surface of the housing; and
a top cover assembly connected to the housing in a sealed manner and configured to close the opening of the housing, where the top cover assembly is provided to be spaced apart from the insulating sheet.
As an optional implementation, in an embodiment of the present application, an air flow channel is formed between the insulating sheet and the top cover assembly.
As an optional implementation, in an embodiment of the present application, the insulating sheet comprises a circumferentially covering area which covers the peripheral surface of the body portion, and the separator is integrally formed with the insulating sheet and serves as a bottom covering area of the insulating sheet, and the bottom covering area covers the bottom end surface of the body portion.
As an optional implementation, in an embodiment of the present application, the separator is a sheet made of insulating material parallel to the bottom end surface, and the sheet made of insulating material has a thickness of 0.1 mm-2 mm.
As an optional implementation, in an embodiment of the present application, at least one surface of the separator is provided with a protruding structure.
As an optional implementation, in an embodiment of the present application, the insulating sheet comprises a circumferentially covering area which covers the peripheral surface of the body portion, and a bottom covering area which covers the bottom end surface of the body portion, and the separator is provided on a side surface of the bottom covering area away from the body portion.
As an optional implementation, in an embodiment of the present application, the separator is provided parallel to the side surface of the bottom covering area away from the body portion.
As an optional implementation, in an embodiment of the present application, the separator and the bottom covering area have a total thickness of 0.1 mm-2 mm.
As an optional implementation, in an embodiment of the present application, the separator and the bottom covering area are provided thereon with corresponding positioning holes for positioning.
As an optional implementation, in an embodiment of the present application, the separator is provided thereon with two first positioning holes, the bottom covering area is provided thereon with two second positioning holes, and the two first positioning holes are located on both ends of the separator and located on the same center line.
As an optional implementation, in an embodiment of the present application, the separator is further provided thereon with a foolproof hole which deviates from the center line of the separator.
As an optional implementation, in an embodiment of the present application, the separator is connected with the bottom covering area by means of hot melting.
As an optional implementation, in an embodiment of the present application, the separator and the bottom covering area are made of the same material through a thermoplastic process.
As an optional implementation, in an embodiment of the present application, the insulating sheet is provided thereon with a liquid-guiding flow channel which partially guides electrolyte between the jelly-roll and the insulating sheet to between the insulating sheet and the housing.
As an optional implementation, in an embodiment of the present application, the battery further comprises a glue tape configured to be provided on the circumferentially covering area or between the circumferentially covering area and the bottom covering area, so that a cavity for covering the jelly-roll is formed and enclosed by the circumferentially covering area and the bottom covering area, and the glue tape is located outside the cavity.
As an optional implementation, in an embodiment of the present application, a glue layer is not provided between the jelly-roll and surfaces of the circumferentially covering area and the bottom covering area of the insulating sheet facing toward the jelly-roll.
As an optional implementation, in an embodiment of the present application, the separator and the jelly-roll satisfy:
L1+3 mm≤L2≤L1+6 mm;
W1+3 mm≤W2≤W1+6 mm;
wherein, L1 is a length of the jelly-roll, W1 is a width of the jelly-roll;
L2 is a length of the separator, and W2 is a width of the separator.
Compared with the prior art, the present application brings about the following beneficial effects:
By the battery provided by embodiments of the present application, the battery comprises a housing having an accommodating cavity and a core assembly provided in the accommodating cavity, where the core assembly further comprises a jelly-roll and an insulating sheet covering the jelly-roll, and the battery implements insulating and protecting for the jelly-roll through covering by the insulating sheet; also, a separator is provided between a bottom end surface of the jelly-roll and a bottom surface of the housing, where corners of the bottom surface of the housing would be designed as rounded corners during processing the housing, and thus, when the jelly-roll is directly placed in the accommodating cavity of the housing, by provision of a separator, the bottom end surface of the jelly-roll may be provided to be spaced apart from the bottom surface of the housing, and the bottom end surface of the jelly-roll may be spaced apart from the rounded corners of the bottom surface of the housing, and thus the jelly-roll may be prevented effectively from colliding with the rounded corners of the housing, and active substances inside the jelly-roll are avoided from falling off that results in a short circuit of the jelly-roll, thereby effectively ensuring normal use of the battery.
Further, by the battery, an opening of the accommodating cavity of the housing is closed by a top cover assembly, and the top cover assembly is provided to be spaced apart from the insulating sheet to prevent the insulating sheet from interfering with the top cover assembly during welding the top cover assembly and the housing which may result in curling of the insulating sheet, which in turn leads to deformation of the insulating sheet. Moreover, when the insulating sheet is provided to be spaced apart from the top cover assembly, space between the insulating sheet and the jelly-roll may be communicated with space between the housing and the insulating sheet, so that gas inside the housing may circulate and flow inside the housing, then heat dissipation function on the jelly-roll may be improved, air pressure difference between the interior and exterior of the housing may be reduced, and the safety of the battery is improved. In addition, during the use of the battery, the jelly-roll would generate gas, and since the space between the insulating sheet and the jelly-roll may be communicated with space between the housing and the insulating sheet, gas generated by the jelly-roll may flow to between the insulating sheet and the housing, then a punching force of the gas generated by the jelly-roll on the insulating sheet may be reduced, and the safety performance of the battery is further improved.
Drawings required for use in the description of embodiments will be introduced briefly below in order to explain the technical solutions of the embodiments of the present application more clearly. It will be apparent that the drawings described below are merely illustrative of some embodiments of the present application, and those skilled in the art can also obtain, from these drawings, other drawings without inventive efforts.
The technical solutions of the present application will be described clearly and completely with reference to the drawings in embodiments of the present application. It is apparent that the embodiments described are only some, but not all of the embodiments of the present application. All the other embodiments, obtained by those skilled in the art in light of the embodiments of the present application without inventive efforts, will fall within the claimed scope of the present application.
In the present application, orientation or positional relationship indicated by terms “on”, “below”, “left”, “right”, “front”, “rear”, “top”, “bottom”, “inside”, “outside”, “center”, “vertical”, “horizontal”, “transversal”, “longitudinal”, etc. is based on the orientation or positional relationship shown in the drawings. These terms are primarily used to better describe the present application and its embodiments, and are not intended to define the indicated device, element or component must have a particular orientation, or must be configured and operated in a particular orientation.
Moreover, in addition to orientation or positional relationship, some of the above terms may be used to indicate other meanings, for example, the term “on” may also be used to indicate a certain dependency or connection relationship in some cases. For an ordinary skilled in the art, the specific meaning of the above terms in the present application may be understood according to specific circumstances.
Furthermore, terms “install”, “provide”, “arrange”, “connect”, and “couple” should be interpreted broadly. For example, the connection may be a fixed connection, a detachable connection, or a unitary structure; it may be a mechanical connection, or an electrical connection; it may be a direct connection, or an indirectly connection made through an intermediate media, or it may be an inside communication between two devices, elements, or components. For an ordinary skilled in the art, the specific meaning of the above terms in the present application may be understood according to specific circumstances.
In addition, terms “first” and “second” etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not intended to indicate or imply indicated relative importance and number of the indicated devices, elements or components. Unless stated otherwise, the wording “plurality” means two or more than two.
Technical solutions of the present application will be further described below in connection with embodiments and the drawings.
Referring to
Corners of the bottom surface 11 of the housing 10 can be designed as rounded corners 12 during processing the housing 10. Thus, when the jelly-roll 21 is directly placed in the accommodating cavity of the housing 10, if the jelly-roll 21 is in direct contact with the housing 10, a contact between the jelly-roll 21 and the rounded corner 12 is a line contact at the position of the rounded corner 12 of the housing 10, in which case a portion where the jelly-roll 21 is in contact with the rounded corner 12 of the housing 10 is subjected to a large pressure, then the active materials inside the jelly-roll 21 would fall off, and there is a short circuit between a positive electrode and a negative electrode inside the jelly-roll 21, and thus the jelly-roll 21 cannot implement normal functions of charging and discharging, resulting in electrical failure of the battery and even danger.
Due to the above reasons, as shown in
In connection with what is shown in
The peripheral surface of the jelly-roll 21 comprises first side surfaces 214 on both side surfaces along its own width direction, and second side surfaces 215 on both side surfaces along its own length direction, and bottom surface 11. During installing the jelly-roll 21, the insulating sheet 22 covers two first side surfaces 214, two second side surfaces 215, and a bottom end surface 213 of the bottom surface 11, thereby insulating and protecting the jelly-roll 21.
Referring back to
In this implementation, the separator 50 is provided parallel to the bottom end surface 213 of the jelly-roll 21 to perform an effect of stably bearing the jelly-roll 21. Moreover, in order to insulate and protect the jelly-roll 21, the separator 50 is an insulating material. In view of a limited internal space of the housing 10 of the battery 100, and in order to further improve efficiency of utilizing the internal space of the housing 10 of the battery 100, the separator 50 is a sheet-like structure, so that the separator 50 bears the jelly-roll 21 while its rate of occupying the internal space of the housing 10 is reduced, and then energy density of the battery 100 is improved.
Further, considering the separator 50 performs an effect of insolating between the bottom end surface 213 of the jelly-roll 21 and the bottom surface 11 of the housing 10, the separator 50 has a thickness H of 0.1 mm to 2 mm, that is, the separator 50 may have the thickness H of 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. Moreover, since the rounded corner 12 of the bottom surface 11 of the housing 10 has a certain size, when a spacing between the bottom end surface 213 of the jelly-roll 21 and the bottom surface 11 of the housing 10 is less than 0.1 mm, interference will inevitably occur between the jelly-roll 21 and the rounded corner 12 of the bottom surface 11 of the housing 10, and there is a great possibility that the active material inside the jelly-roll 21 will fall off, which will severely affect the stability of the electrical performance of the jelly-roll 21. When a distance between the bottom end surface 213 of the jelly-roll 21 and the bottom surface 11 of the housing 10 is greater than 2 mm, the core assembly 20 will occupy a relatively large space of the accommodating cavity of the housing 10, resulting in an overall larger size of the battery, affecting the design of the structure of the battery, and reducing the energy density of the battery.
Optionally, as shown in
In addition, by providing the protruding structure 514 on at least one surface of the separator 50, difficulty of processing and manufacturing the separator 50 may be reduced. When surface of the separator 50 is too smooth, two separators 50 placed on top of each other would likely be sticky, and are not easy to separate, and consequently it takes longer time to separate the separator 50 individually during manufacturing, which severely affects the production efficiency.
The protruding structure 514 may be a boss, a protruding bump, a protruding strip, and the like, and other structures that can protrude from the surface of the separator 50 are not specifically defined in the present embodiment.
Referring to
Further, in order to implement the stability that the separator 50 bears the jelly-roll 21, the separator 50 is provided in parallel to the side surface of the bottom covering area 222 of the insulating sheet 22 away from the body portion 211, so as to realize the fixing stability of the separator 50, the insulating sheet 22 and the jelly-roll 21, preventing the jelly-roll 21 and the insulating sheet 22 from falling off the separator 50; by parallel provision, the separator 50 may be stressed more evenly, preventing uneven stress of the separator 50 which leads to breakage and damage, and affects the service life of the battery 100.
When the separator 50 and the insulating sheet 22 are provided separately, the bottom covering area 222 of the insulating sheet 22 and the separator 50 have a total thickness H of 0.1 mm to 2 mm, that is, the bottom covering area 222 of the insulating sheet 22 and the separator 50 may have a total thickness H of 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, etc. Moreover, since the rounded corner 12 of the bottom surface 11 of the housing 10 has a certain size, when a spacing between the bottom end surface 213 of the jelly-roll 21 and the bottom surface 11 of the housing 10 is less than 0.1 mm, interference will inevitably occur between the jelly-roll 21 and the rounded corner 12 of the bottom surface 11 of the housing 10, and there is a great possibility that the active material inside the jelly-roll 21 will fall off, which will severely affect the stability of the electrical performance of the jelly-roll 21. When a distance between the bottom end surface 213 of the jelly-roll 21 and the bottom surface 11 of the housing 10 is greater than 2 mm, the core assembly 20 will occupy a relatively large space of the accommodating cavity of the housing 10, resulting in an overall larger size of the battery, affecting the design of the structure of the battery, and reducing the energy density of the battery.
Further, considering that the separator 50 needs to support the jelly-roll 21, and the insulating sheet 22 only needs to insulate and protect the jelly-roll 21, as viewed from the influence of the stress characteristics of the separator 50 and the insulating sheet 22 on their structural strength, the separator 50 may have a thickness greater than or equal to that of the insulating sheet 22, or the separator 50 has a thickness twice that of the insulating sheet 22, or the separator 50 may have a thickness which is third times of the thickness of the insulating sheet 22, and so on, so that the separator 50 can better support the jelly-roll 21 when the separator is impacted from the outside, then the separator 50 performs the buffering and shock absorption effect on the jelly-roll 21.
The insulating sheet 22 may have a thickness of 0.1 mm-1 mm. When the insulating sheet 22 has a thickness that is too small, strength of the insulating sheet 22 cannot be guaranteed, and the insulating sheet is easily damaged; when the insulating sheet 22 has a thickness that is overly large, the portability of the secondary battery 100 cannot be achieved, and also the housing 10 is required to have a larger accommodating cavity to accommodate the jelly-roll 21 and the insulating sheet 22, resulting in a larger size of the secondary battery 100.
The separator 50 may have a thickness of 0.1 mm-2 mm. When the separator 50 has a thickness that is too small, bearing strength of the separator 50 cannot be guaranteed, and the separator is easily damaged; when the separator 50 has a thickness that is too large, the portability of the secondary battery 100 cannot be achieved, and also the thicker separator 50 requires the housing 10 to have a larger accommodating cavity to accommodate the separator 50, resulting in a larger size of the secondary battery 100.
Considering comprehensively the above thickness relationship between the separator 50 and the insulating sheet 22, and conditions of the thickness ranges of the separator 50 and the insulating sheet 22, an example of the thickness relationship between the insulating sheet 22 and the separator 50 is as follows:
When the insulating sheet 22 has a thickness of 0.15 mm, the separator 50 may have a thickness of 0.30 mm or 0.45 mm, etc.; when the insulating sheet 22 has a thickness of 0.5 mm, the separator 50 may have a thickness of 1.0.0 mm or 1.5 mm, etc.; when the insulating sheet 2220 has a thickness of 1.0 mm, the separator 50 may have a thickness of 2.0 mm the insulating sheet 22 and the separator 50.
It may be understood that the above thicknesses of the separator 50 and the insulating sheet 22 are only some examples. In practical applications, it is sufficient as long as the thicknesses of the insulating sheet 22 and the separator 50 satisfy the above thickness range at the same time, and their specific thickness values are not specifically defined in the present embodiment.
When the separator 50 and the insulating sheet 22 are provided separately, the separator 50 is connected to a side of the bottom covering area 222 of the insulating sheet 22 away from the jelly-roll 21. By providing the separator 50 between the jelly-roll 21 and the bottom surface 11 of the housing 10, the jelly-roll 21 is supported by the separator 50. When the housing 10 is impacted by the outside, the separator 50 may be used to buffer and dampen the impact from the housing 10, so as to reduce the impact effect of the external impact on the jelly-roll 21. Therefore, the jelly-roll 21 is protected better, the active material is prevented from falling off when the jelly-roll 21 is impacted, which leads to an internal short circuit.
Since the structure inside the battery 100 needs to perform an insulating and protecting effect on the jelly-roll 21, the insulating sheet 22 and the separator 50 are both insulating materials, and are made by a thermoplastic process. The insulating sheet 22 and the separator 50 made by a thermoplastic process have high toughness and good impact resistance. As an example, the insulating sheet 22 and the separator 50 are generally polymer insulating materials. For example, the separator 50 may be polypropylene, polyethylene, etc., and the insulating sheet 22 may be polypropylene, polyethylene, etc.
Further, when connection between the insulating sheet 22 and the separator 50 fails, the separator 50 will move relative to the insulating sheet 22, and in this case the insulating sheet 22 will be subject to a friction force from the separator 50, and consequently the insulating sheet 22 is damaged by friction and cannot perform a good insulating and protecting effect on the jelly-roll 21. Therefore, in order to achieve a stable connection between the separator 50 and the insulating sheet 22, a hot melting connection may be used between the insulating sheet 22 and the separator 50. A surface where the separator 50 is connected with the insulating sheet 22 is the first surface 51, where the surface 51 has a third hot melting connection position 511, and the bottom covering area 222 of the bottom surface 11 of the insulating sheet 22 has a fourth hot melting connection position 2221. When the separator 50 and the insulating sheet 22 are hot melted, the third hot melting connection position 511 and the fourth hot melting connection position 2221 may be hot melted for connection, so that a stable connection between the insulating sheet 22 and the separator 50 may be achieved, and then the insulating sheet 22 performs a good insulating and protecting effect on the jelly-roll 21.
Further, in order to further improve the connection stability of the hot melting connection between the separator 50 and the insulating sheet 22, the separator 50 and the insulating sheet 22 are selected as the same material. When the separator 50 and the insulating sheet 22 are made of the same polymer material, the separator 50 and the insulating sheet 22 have the same molecular structure, and they can have a strong bonding force when hot melted, so that a stable connection between the separator 50 and the insulating sheet 22 may be implemented, relative movement between the separator 50 and the insulating sheet 22 may be further prevented, which then damages the insulating sheet 22 and causes decreases in the performance stability of the battery 100 or even unusable situations.
Optionally, the separator 50 and the insulating sheet 22 are both polypropylene materials. Since the polypropylene material is a polymer insulating material, when this material is used for the separator 50 and the insulating sheet 22, insulating and protecting for the jelly-roll 21 may be implemented. Moreover, since polypropylene material is not stretchable, a single-layer film structure is easily formed, and when this material is used for the separator 50 and the insulating sheet 22, they have a stronger bearing capacity and are not easily damaged, thereby improving the service life of the battery 100. It may be understood that, in other embodiments, the materials for the separator 50 and the insulating sheet 22 can also select polyethylene or other polymer insulating materials, and their specific materials may be selected as actually needed, and are not specifically defined in the present embodiment.
In some embodiments, referring to
Further, distance between the two first positioning holes 512 should not be less than half of the size of the first surface 51 along the length direction, that is, half of the length L2 of the separator 50, because the larger the distance between the two first positioning holes 512 is, the smaller the linear error determined by the two first positioning holes 512 will be, and the more accurate the positioning accuracy of the first positioning hole 512 will be. Therefore, the distance between the two first positioning holes 512 should not be less than half of the length of the separator 50.
Further, in order to ensure the bearing strength of the separator 50, diameter of the first positioning hole 512 should not be greater than 3 mm, and for example it may be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, and the like. Regardless of the first positioning hole 512 being a blind hole or a through hole, due to presence of the first positioning hole 512, material thickness of the separator 50 at the position of the first positioning hole 512 is smaller than that of other structures not provided with an opening, so that the bearing capacity of the separator 50 at the position of the first positioning hole 512 decreases. Therefore, the diameter of the first positioning hole 512 cannot be too large.
In some embodiments, considering that the separator 50 and the insulating sheet 22 are hot melted for connection, position of the first positioning hole 512 may avoid the third hot melting connection position 511 of the separator 50, thereby avoiding the first positioning hole 512 from not being easily identified because the first positioning hole 512 is blocked by the third hot melting connection position 511.
It may be understood that, in some other embodiments, position of the first positioning hole 512 may also be provided at the third hot melting connection position 511 of the separator 50. In this case, after a relative position of the separator 50 and the insulating sheet 22 is determined, hot melting connection is performed, where the first positioning hole 512 may be filled with material through the hot melting connection, to enhance the bearing strength of the separator 50.
Correspondingly, as shown in
It may be understood that the first positioning hole 512 and the second positioning hole 2222 may be both through holes. When they are through holes, the electrolyte may circulate through the positioning holes, which may improve infiltration degree of the electrolyte.
In some embodiments, considering that the separator 50 and the insulating sheet 22 are hot melted for connection, position of the second positioning hole 2222 may avoid the fourth hot melting connection position 2221 of the insulating sheet 22, thereby avoiding the second positioning hole 2222 from not being easily identified because the second positioning hole 2222 is blocked by the fourth hot melting connection position 2221.
It may be understood that, in some other embodiments, the position of the second positioning hole 2222 may be provided at the fourth hot melting connection position 2221 of the insulating sheet 22. In this case, after a relative position of the separator 50 and the insulating sheet 22 is determined, hot melting connection is performed, where the second positioning hole 2222 may be filled with material through the hot melting connection, to enhance the bearing strength of the insulating sheet 22.
In some embodiments, referring to
In connection with what is shown in
Further, referring back to
L2=L1±5 mm;
W2=W1±5 mm;
wherein L2 is a length of the separator 5030, and W2 is a width of the separator 5030.
As may be seen from the foregoing, L1 is a length of the jelly-roll 21, and W1 is a width of the jelly-roll 21, that is, length L2 of the separator 50 may be L1+5 mm, L1+4.6 mm, L1+3 mm, etc., and width W2 of the separator 50 may be W1+6 mm, W1+5 mm, W1+3 mm, etc. It may be understood that the above sizes in length and width directions of the separator 50 are just some examples. In the actual design process, it is sufficient as long as the size of the separator 50 and the size of the jelly-roll 21 satisfy the above relationship expression, and sizes thereof are not specifically defined in the present embodiment.
Considering that the insulating sheet 22 is mainly used for covering the jelly-roll 21, the following will describe in detail how the insulating sheet 22 covers the jelly-roll 21 with reference to the accompanying drawings.
In some embodiments, referring to
In an example, as shown in
Further, when the second side surface 215 of the jelly-roll 21 is covered by a flank, as shown by the structural form of the insulating sheet 22 in
Or as shown by the structural form of the insulating sheet 22 in
It may be understood that, regardless of a mode where the edge of the first flank 221a and the edge of the third flank 221c are just connected, or a mode where the first flank 221a and the third flank 221c partially overlap, the first flank 221a and the third flank 221c may have the same or different size, as long as the above connection mode may be achieved, and magnitude of the relative size between the first flank 221a and the third flank 221c is not specifically defined in the present embodiment.
Since the second flank 221b and the first flank 221a have the same structural size, and the third flank 221c and the fourth flank 221d have the same structural size, the connection mode of the second flank 221b and the fourth flank 221d can refer to the above connection mode of the first flank 221a and the third flank 221c, which will not be repeated here.
In the above solution, a case is provided in which the first flank 221a and the second flank 221b have the same size and shape, and the third flank 221c and the fourth flank 221d have the same size and shape. Considering that the structure of the jelly-roll 21 is approximately a square block structure, when the first flank 221a and the second flank 221b have a different size, and the third flank 221c and the fourth flank 221d have a different size, it is sufficient as long as a full covering of the jelly-roll 21 may be achieved, where a size relationship between the first flank 221a and the second flank 221b and a size relationship between the third flank 221c and the fourth flank 221d are not specifically defined here.
Further, as shown by the structural form of the insulating sheet 22 in
The bending area may be formed by imprinting indentation on the insulating sheet 22, and a bending area may be formed between every two indentations. The insulating sheet 22 may be bent easily at the indentation position by means of imprinting indentation, and the insulating sheet 22 may easily form a covering cavity.
It may be understood that, the bending area may also be formed integrally when the insulating sheet 22 is formed, or formed by other methods, that is, the formation thereof is not specifically defined in the present embodiment.
In another example, as shown by the structural form of the insulating sheet 22 in
Further, when the second side surface 215 of the jelly-roll 21 is covered by a flank, as shown by the structural form of the insulating sheet 22 in
Since two second side surfaces 215 of the jelly-roll 21 have the same structural size, the connection mode of the second flank 221b and the first covering area 2211 can refer to the above connection mode of the first flank 221a and the second covering area 2212, which will not be repeated here.
Referring back to the structural form of the insulating sheet 22 shown in
Referring to the structural form of the insulating sheet 22 shown in
In another example, as shown by the structural form of the insulating sheet 22 in
Further, as shown by the structural form of the insulating sheet 22 in
Since two second side surfaces 215 of the jelly-roll 21 have the same structural size, the connection mode of the second flank 221b and the second covering area 2212 can refer to the above connection mode of the first flank 221a and the second covering area 2212, which will not be repeated here.
Referring back to the structural form of the insulating sheet 22 shown in
Referring to the structural form of the insulating sheet 22 shown in
In order to realize a complete covering of the jelly-roll 21 by the insulating sheet 22, now the structure of the above first insulating sheet 22, that is, the structure of the insulating sheet 22 as shown in
Length X1 of the first covering area 2211 should not be less than height H1 of the jelly-roll 21, width Y1 of the first covering area 2211 should not be less than length L1 of the jelly-roll 21, width Y2 of the first flank 221a should not be less than half of width W1 of the jelly-roll 21, and width Y3 of the second covering area 2212 should not be less than width W1 of the jelly-roll 21;
X1≥H1;
Y1≥L1;
Y2≥½W1;
Y3≥W1;
moreover, in order to realize tightness of covering of the jelly-roll 21 by the insulating sheet 22, and to save space, the size relationship between the insulating sheet 22 and the jelly-roll 21 should satisfy:
X1≤H1+5 mm;
Y1≤L1+5 mm;
Y2≤W1;
Y3≤W1+5 mm;
that is, length X1 of the first covering area 2211 may be H1, H1+0.1 mm, H1+0.2 mm, H1+0 5 mm, H1+1 mm, H1+2 mm, H1+5 mm; width Y1 of the first covering area 2211 may be L1, L1+0.1 mm, L1+0.2 mm, L1+0.5 mm, L1+1 mm, L1+2 mm, L1+5 mm; width Y2 of the first flank 221a may be ½W1, ⅔W1, ¾W1, W1; width Y3 of the second covering region 2212 may be W1, W1+0.1 mm, W1+0.2 mm, W1+0.5 mm, W1+1 mm, W1+2 mm, W1+5 mm.
It may be understood that the above sizes of the insulating sheet 22 are just some examples. In the actual design process, it is sufficient as long as the size of the insulating sheet 22 and the size of the jelly-roll 21 satisfy the above relationship expression, and sizes thereof are not defined specifically in the present embodiment.
In some embodiments, referring to
Further, the glue tape 30 may be pasted to connection portion of the first flank 221a and the third flank 221c, and connection portion of the second flank 221b and the fourth flank 221d, of the insulating sheet 22. By pasting the glue tape 30 at the above position, fixing of the insulating sheet 22 may be performed, and weak position of the insulating sheet 22 may be strengthened. It may be understood that only one pasting position of the glue tape 30 is given in the present embodiment, and the specific pasting position may be adjusted as actually needed, which is not specifically defined in the present embodiment.
Further, no glue layer is provided between the insulating sheet 22 and the jelly-roll 21, that is, a surface of a side of the insulating sheet 22 inside the cavity is not provided with a glue layer, then the insulating sheet 22 and the jelly-roll 21 are mainly fixed by the above glue tape 30. If the cavity of the insulating sheet 22 is fixed relative to the jelly-roll 21, a glue layer is used for fixing, that is, a glue layer is provided on a surface of a side of the insulating sheet 22 inside the cavity, and then the insulating sheet 22 is pasted on the glue layer. During subsequent maintenance to the jelly-roll 21, the insulating sheet 22 is not easily disassembled. And also residual glue will remain on the surface of the jelly-roll 21, which affects the subsequent installation of a new insulating sheet 22. In addition, by canceling provision of the glue layer on outer surface of the jelly-roll 21, heat of the jelly-roll 21 may be avoided from not being dissipated due to presence of the glue layer, that is, by canceling provision of the glue layer, heat dissipation performance of the jelly-roll 21 may be improved. In addition, by canceling provision of the glue layer, there is a certain spacing space between the jelly-roll 21 and the insulating sheet 22, and in this case space where the electrolyte circulate and flow may be enlarged, and infiltration degree of the electrolyte may be improved.
In some embodiments, in order to circulate and flow the electrolyte between the insulating sheet 22 and the jelly-roll 21, to improve the infiltration effect of the electrolyte, the insulating sheet 22 is provided thereon with a liquid-guiding flow channel 223, which then provides the electrolysis with a circulation channel inside the housing 10. As may be seen from the foregoing, the cavity enclosed by the insulating sheet 22 for covering the jelly-roll 21 is mainly formed by the above peripheral covering area 221 and bottom covering area 222 bonded by a glue tape. Therefore, the liquid-guiding flow channel 223 may be a gap where a junction of each covering area is formed, for example a junction between the first flank 221a and the third flank 221c, a junction between the second flank 221b and the fourth flank 221d, a connection gap between the first flank 221a and the bottom covering area 222, and a connection gap between the third flank 221c and the bottom covering area 222, and the like.
Since connection of each covering area of the insulating sheet 22 is fixed by the glue tape 30, there is a connection gap that can allow the electrolyte to pass through at connection boundary of each covering area. In this case, it is no longer necessary to provide separately the liquid-guiding flow channel 223 on the insulating sheet 22, which reduces the difficulty of the design of the structure of the insulating sheet 22 while infiltration effect of the electrolyte is improved.
It may be understood that, in other embodiments, the liquid-guiding flow channel 223 may also be formed by providing holes directly at any position of the peripheral covering area 221 of the insulating sheet 22. For example, the first covering area 2211, the first flank 221a, the second flank 221b, the second covering area 2212, the third flank 221c, and the fourth flank 221d are provided with through holes. Also, the electrolyte can circulate and flow in the space between the jelly-roll 21 and the insulating sheet 22 and the space between the insulating sheet 22 and the housing 10, thereby improving infiltration efficiency of the electrolyte.
As may be seen, the formation mode of the liquid-guiding flow channel 223 is not specifically defined in the present embodiment as long as the electrolyte circulates and flows.
In some embodiments, as shown in
The top cover assembly 40 comprises a top cover plate 41 and a lower plastic member 42 connected to a lower surface of the top cover plate 41 facing towards the jelly-roll 21. The top cover plate 41 is connected to the opening of the housing 10 by welding to close the accommodating cavity of the housing 10. A plurality of connection bosses 421 extending towards the jelly-roll 21 are provided at the peripheral edge of the lower plastic member 42. After the insulating sheet 22 forms a cavity for covering the jelly-roll 21, the jelly-roll 21 is placed inside the cavity. In order to achieve a comprehensive protection for the jelly-roll 21, the insulating sheet 22 is covering the outer peripheral surface of each connection boss 421 at the same time. Considering that the connection boss 421 is also made of plastic material, in order to achieve a stable connection between the insulating sheet 22 and the lower plastic member 42, each connection boss 421 has a first hot melting connection position 42a, and the insulating sheet 22 also has a second hot melting connection position 2213, where the insulating sheet 22 and the plurality of connection bosses 421 are hot melted for connection in the hot melting connection area, thereby achieving a stable connection between the insulating sheet 22 and the top cover assembly 40, then achieving a comprehensive protection for the jelly-roll 21.
As shown in
Further, there is a spacing between the top surface 224 of the insulating sheet 22, i.e., a surface facing toward the top cover plate 41, and the lower surface of the top cover plate 41 (i.e., a surface of the top cover plate 41 facing toward the jelly-roll 21). In this way, on the one hand, the insulating sheet 22 may be prevented from interfering with the top cover assembly 40 during welding the top cover assembly 40 and the housing 10, resulting in curling of the insulating sheet 22 and then deformation of the insulating sheet 22. On the other hand, when the insulating sheet 22 is provided to be spaced apart from the top cover assembly 40, by providing a spacing, a gas flow channel may be formed between the insulating sheet 22 and the top cover plate 41, which gas flow channel allows gas between the insulating sheet 22 and the jelly-roll 21 to flow to between the insulating sheet 22 and the housing 10. Then the space between the insulating sheet 22 and the jelly-roll 21 may be communicated with the space between the housing 10 and the insulating sheet 22. Therefore, gas inside the housing 10 may circulate and flow in the housing 10, and then heat dissipation function of the jelly-roll 21 may be improved, air pressure difference between the interior and exterior of the housing 10 may be reduced, and the safety of the battery 100 may be improved. In addition, considering that the jelly-roll 21 would generate gas during the use of the battery 100, since the space between the housing 10 and the insulating sheet 22 may be communicated with the space between the insulating sheet 22 and the jelly-roll 21, the gas generated by the jelly-roll 22 may flow to between the insulating sheet 22 and the housing 10, and then a punching force of the gas generated by the jelly-roll 21 on the insulating sheet 21 may be alleviated, and the safety performance of the battery 100 may be further improved.
The battery disclosed by the embodiments of the present application has been described in detail above, and the principles and implementations of the present application have been described with specific examples herein. The description of the above embodiments is only for helping to understand the battery and its core idea of the present application. Moreover, there will be changes in the specific implementation and application scopes for an ordinarily skilled in the art in view of the idea of the present application. In summary, the content of the description shall not be construed as limiting the present application.
Number | Date | Country | Kind |
---|---|---|---|
202122406131.8 | Sep 2021 | CN | national |