Patent Publication Number: US-2023155264-A1

Title: Secondary Battery and Device Including the Same

Description:
TECHNICAL FIELD 
     Cross Citation with Related Application(s) 
     This application claims the benefit of Korean Patent Application No. 10-2020-0128637 filed on Oct. 6, 2020 and Korean Patent Application No. 10-2021-0131694 filed on Oct. 5, 2021 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety. 
     The present disclosure relates to a secondary battery and a device including the same, and more particularly to a secondary battery having improved cooling performance and a device including the same. 
     BACKGROUND 
     Along with the increase of technology development and demands for mobile devices, the demand for batteries as energy sources is increasing rapidly. In particular, a secondary battery has attracted considerable attention as an energy source for power-driven devices, such as an electric bicycle, an electric vehicle, and a hybrid electric vehicle, as well as an energy source for mobile devices, such as a mobile phone, a digital camera, a laptop computer and a wearable device. 
     Based on the shape of a battery case, such a secondary battery is classified into a cylindrical battery where an electrode assembly is built in a cylindrical metal can, a prismatic battery where an electrode assembly is built in a prismatic metal can, and a pouch type battery where an electrode assembly is built in a pouch type case formed of an aluminum laminate sheet. Among them, the cylindrical battery has an advantage of having a relatively large capacity and being structurally stable. 
     Particularly, in the case of a large-capacity secondary battery requiring high output, as the diameter and/or size of the battery increases, the thickness increases. With the conventional external cooling method, it may be difficult to perform sufficient cooling inside the secondary battery. Further, uniform cooling inside the secondary battery is impossible. In addition, the conventional external cooling method may form an excessive temperature gradient inside the secondary battery, and thus deviations may occur in the performance and deterioration of the secondary battery, and the risk of fire due to lithium deposition or overheating may also exist. Therefore, there is a need to develop a secondary battery having improved cooling performance in consideration of the large capacity of the secondary battery. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Technical Problem 
     It is an object of the present disclosure to provide a secondary battery having improved cooling performance and a device including the same. 
     The objects of the present disclosure are not limited to the aforementioned objects, and other objects which are not described herein should be clearly understood by those skilled in the art from the following detailed description and the accompanying drawings. 
     Technical Solution 
     According to one aspect of the present disclosure, there is provided a secondary battery secondary battery comprising: a jelly roll electrode assembly in which a cathode sheet, an anode sheet, and a separator interposed between the cathode sheet and the anode sheet are wound together; and a battery case to which the jelly roll electrode assembly is mounted, wherein the battery case is configured such that a flow path recessed toward the center of the jelly roll electrode assembly is formed in the lower part of the battery case, wherein the flow path comprises a first flow path and a second flow path located in the center of the first flow path, and wherein an upper part of the second flow path is opened toward the upper part of the first flow path. 
     A protrusion may be formed in at least any one of the first flow path and the second flow path. 
     The protrusion may be formed on the first flow path. 
     The protrusion may include at least two protrusions. 
     The protrusion may be formed of a cooling fin. 
     The at least two protrusions may be spaced apart from each other by the same distance. 
     The protrusions may be formed in a linear shape or a semicircular shape. 
     A diameter of the first flow path may be smaller than a diameter of a center of the jelly roll electrode assembly. 
     A height of the first flow path and the second flow path may be smaller than a height of the jelly roll electrode assembly. 
     A nozzle may be connected to the lower part of the second flow path, and a positive or negative pressure may be applied from the nozzle to the inside of the second flow path. 
     At least two connection parts may be located between the first flow path and the second flow path. 
     The connection part may be extended from a lower part to an upper part of the first flow path or the second flow path. 
     According to another aspect of the present disclosure, there is provided a device comprising the above-mentioned secondary battery. 
     Advantageous Effects 
     According to embodiments, the secondary battery of the present disclosure and a device including the same can improve the cooling performance. 
     The effects of the present disclosure are not limited to the effects mentioned above and additional other effects not described above will be clearly understood from the detailed description and the appended drawings by those skilled in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a partial cross-sectional view of a secondary battery according to an embodiment of the present disclosure; 
         FIG.  2    is an enlarged view of the lower part of the flow path included in the secondary battery of  FIG.  1   ; 
         FIG.  3    is a diagram showing a structure in which an external nozzle is coupled to the secondary battery of  FIG.  1   ; 
         FIGS.  4  and  5    are partial cross-sectional views of a secondary battery according to another embodiment of the present disclosure; and 
         FIG.  6    is a cross-sectional view schematically showing a cross section of a flow path included in a secondary battery according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out them. The present disclosure may be modified in various different ways, and is not limited to the embodiments set forth herein. 
     Portions that are irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals designate like elements throughout the specification. 
     Further, in the drawings, the size and thickness of each element are arbitrarily illustrated for convenience of description, and the present disclosure is not necessarily limited to those illustrated in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, for convenience of description, the thicknesses of some layers and regions are exaggerated. 
     Further, throughout the specification, when a portion is referred to as “including” a certain component, it means that the portion can further include other components, without excluding the other components, unless otherwise stated. 
     Further, throughout the specification, when referred to as “planar”, it means when a target portion is viewed from the upper side, and when referred to as “cross-sectional”, it means when a target portion is viewed from the side of a cross section cut vertically. 
     Now, the secondary battery according to an embodiment of the present disclosure will be described. However, the secondary battery herein is not limited to a cylindrical battery, and secondary batteries having various shapes may be described with identical or similar contents. 
       FIG.  1    is a partial cross-sectional view of a secondary battery according to an embodiment of the present disclosure.  FIG.  2    is an enlarged view of the lower part of the flow path included in the secondary battery of  FIG.  1   . 
     Referring to  FIG.  1   , a secondary battery  100  according to an embodiment of the present disclosure includes a jelly roll electrode assembly  110  in which a cathode sheet, an anode sheet, and a separator interposed between the cathode sheet and the anode sheet are wound together, and a battery case  120  to which the jelly roll electrode assembly  110  is mounted. Here, the battery case  120  is configured such that flow paths  130  and  140  recessed toward the center of the jelly roll electrode assembly  110  are formed in the lower part of the battery case  120 . 
     Thereby, the secondary battery  100  according to the present embodiment is configured such that the flow paths  130  and  140  are formed in the lower part of the battery case  120  and thus, the fluid flowing into and moving to the flow paths  130  and  140  can absorb heat generated in the center of the jelly roll electrode assembly  110 . Thereby, the secondary battery  100  according to the present embodiment can improve the cooling performance. 
     The flow paths  130  and  140  include a first flow path  130  and a second flow path  140  located at the center of the first flow path  130 . Here, the upper part of the second flow path  140  is opened toward the upper part of the first flow path  130 . Thereby, the fluid flowing into or flowing out to the first flow path  130  from the second flow path  140  may move in all directions toward the upper part of the first flow path  130 . 
     Further, the first flow path  130  and the second flow path  140  allow the fluid to move through their respective upper parts. In one example, the fluid flowing into the second flow path  140  moves to the upper part of the second flow path  140  and flows into the upper part of the first flow path  130 . The fluid flowing into the upper part of the first flow path  130  may move toward the lower part of the first flow path  130 . On the contrary, the fluid flowing into the first flow path  130  moves to the upper part of the first flow path  130  and flows into the upper part of the second flow path  140 . The fluid flowing into the upper part of the second flow path  140  may move toward the lower part of the first flow path  130 . 
     Thereby, the flow paths  130  and  140  include the first flow path  130  and the second flow path  140 , and the fluid flowing into the flow paths  130  and  140  can sequentially move through the first flow path  130  and the second flow path  140 , so that the movement path of the fluid can be formed long. Further, the long-formed fluid movement path can increase the time during which the fluid flows into the flow paths  130  and  140 . Further, the cooling performance of the jelly roll electrode assembly  110  can be improved. 
     In addition, the flow paths  130  and  140  allow the fluid to move through the upper parts of the first flow path  130  and the second flow path  140 , respectively, so that a movement path formed by the first flow path  130  and the second flow path  140  may be formed longer. Further, cooling can be easily performed not only at the center of the jelly roll electrode assembly  110  adjacent to the outer surface of the battery case, but also at the upper end of the center of the jelly roll electrode assembly  110 . 
     Referring to  FIGS.  1  and  2   , the diameters of the first flow path  130  and the second flow path  140  may be smaller than the diameter of the center of the jelly roll electrode assembly  110 . In particular, the diameter of the first flow path  130  is smaller than the diameter of the center of the jelly roll electrode assembly  110 , wherein the diameter of the second flow path  140  may be smaller than a diameter of the first flow path  130 . Further, the height of the first flow path  130  and the second flow path  140  may be smaller than the height of the jelly roll electrode assembly  110 . In particular, the height of the first flow path  130  is smaller than the height of the jelly roll electrode assembly  110 , wherein the height of the second flow path  140  may be smaller than the height of the first flow path  130 . 
     Referring to  FIGS.  1  and  2   , the secondary battery  100  according to the present embodiment may be configured such that at least two connection parts  150  are located between the first flow path  130  and the second flow path  140 . Also, the connection parts  150  may be extended from a lower part to an upper part of the first flow path  130  or the second flow path  140 . 
     Thereby, the connection part  150  can fix the second flow path  140  to the first flow path  130  without interfering with the fluid flowing into or moving to the first flow path  130  and the second flow path  140 . 
     As an example, the connection part  150  can be formed of a material such as a cooling fin. However, the material of the connection part  150  is not limited to the cooling fin, and any member having high thermal conductivity can be included in the present embodiment. 
     Therefore, the connection part  150  can increase the movement time of the fluid moving along the connection part  150  in addition to the effect of fixing the first flow path  130  and the second flow path  140  to each other, and thus the cooling performance can also be further improved. 
       FIG.  3    is a diagram showing a structure in which an external nozzle is coupled to the secondary battery of  FIG.  1   . Referring to  FIG.  3   , in the secondary battery  100  according to the present embodiment, a nozzle  200  may be connected to the lower part of the second flow path  140 . Here, the nozzle  200  can apply a positive pressure or a negative pressure to the inside of the second flow path  140 . 
     Referring to  FIG.  3 ( a ) , when the nozzle  200  applies a negative pressure to the inside of the second flow path  140 , the fluid in the inside of the second flow path  140  moves to the lower part of the second flow path  140  by the nozzle  200 , and the fluid in the upper part of the first flow path  130  fills the upper part of the second flow path  140 . Thereby, the fluid in the lower part of the first flow path  130  also moves to the upper part of the first flow path  130 , and the lower part of the first flow path  130  allows the external fluid to move to the inside of the first flow path. 
     Similarly, referring to  FIG.  3 ( b ) , when the nozzle  200  applies a positive pressure to the inside of the second flow path  140 , the fluid in the inside of the second flow path  140  moves to the upper part of the second flow path  140  by the nozzle  200 , and the fluid in the inside of the first flow path  130  moves to the lower part of the first flow path  140 . Thereby, the fluid in the lower part of the first flow path  130  moves to the outside. 
     Therefore, in the secondary battery  100  according to the present embodiment, when the nozzle  150  is connected to the flow paths  130  and  140  and a positive or negative pressure is applied, the fluid in the inside of the flow paths  130  and  140  may move through a movement path formed by the first flow path  130  and the second flow path  140 . Thereby, cooling of the center of the jelly roll electrode assembly  110  located adjacent to the flow paths  130  and  140  can be smoothly performed, and the cooling performance can be further improved by the pressure applied from the nozzle  150 . 
       FIGS.  4  and  5    are partial cross-sectional views of a secondary battery according to another embodiment of the present disclosure. 
     Referring to  FIGS.  4  and  5   , a protrusion  135  may be formed in at least any one of the first flow path  130  and the second flow path  140 . 
     As an example, the protrusion  135  may be formed on the first flow path  130 . Here, the protrusion  135  may be formed on the first flow path  130  and may be protruded toward the second flow path  140 . Thus, the protrusion  135  is formed on the first flow path  130  adjacent to the jelly roll electrode assembly  110 , so that the cooling performance of the jelly roll electrode assembly  110  can be further improved. 
     However, the position of the protrusion  135  is not limited thereto, and can be formed on both the first flow path  130  and the second flow path  14 . 
     More specifically, the height of the protrusion  135  may be smaller than the distance between the first flow path  130  and the second flow path  140 . Therefore, the first flow path  130  includes the protrusion  135 , so that the movement time of the fluid flowing between the first flow path  130  and the second flow path  140  can be lengthened, and the cooling performance can also be improved. 
     Further, the protrusion  135  may include at least two protrusions. The at least two protrusions may be spaced apart from each other by the same distance. Thereby, in the secondary battery  100  according to the present embodiment, the degree of cooling by the fluid flowing between the first flow path  130  and the second flow path  140  may be uniform. However, the present disclosure is not limited thereto, and the at least two protrusions may be spaced apart asymmetrically or by a non-uniform distance. 
     Further, the protrusion  135  includes at least two protrusions, and the protrusions may be formed of cooling fins. Thereby, the secondary battery  100  according to the present embodiment can further improve the cooling performance by the fluid flowing between the first flow path  130  and the second flow path  140 . 
     Further, referring to  FIGS.  4  and  5   , the protrusion  135  includes at least two protrusions, and the protrusions may be formed in a linear shape or a semicircular shape. More preferably, the protrusion may have gently formed edges. Thereby, in the secondary battery  100  according to the present embodiment, the fluid flowing between the first flow path  130  and the second flow path  140  can move easily without being stagnated in a specific part. 
       FIG.  6    is a cross-sectional view schematically showing a cross section of a flow path included in a secondary battery according to another embodiment of the present disclosure. 
     Referring to  FIG.  6 ( a ) , in the secondary battery according to the present embodiment, a protrusion  135  extending in the form of a screw may be formed along between the first flow path  130  and the second flow path  140 . More specifically, the protrusion  135  may be extended in an oblique direction along between the first flow path  130  and the second flow path  140 . 
     Thereby, the length of the protrusion  135  extending along between the first flow path  130  and the second flow path  140  can be maximized, so that the movement time of the fluid flowing between the first flow path  130  and the second flow path  140  can be lengthened. That is, the contact time between the fluid and the first flow path  130  relative to the amount of the injected fluid can be effectively increased, and the cooling performance can also be improved accordingly. 
     Referring to  FIG.  6 ( b ) , in the secondary battery according to the present embodiment, a protrusion  135  is formed between the first flow path  130  and the second flow path  140 , and the protrusion  135  may include at least two rectangular plate-shaped protrusions. At this time, similarly to  FIGS.  4  and  5   , each of the protrusions may be spaced apart from each other by the same distance. However, the present disclosure is not limited thereto, and each of the protrusions may be spaced apart from each other asymmetrically or by a non-uniform distance. 
     Thereby, the protrusion  135  includes a plate-shaped projection, so that the contact area with the fluid flowing between the first flow path  130  and the second flow path  140  can be increased, and the cooling performance can also be improved accordingly. In addition, the protrusion  135  is formed on the first flow path  130  adjacent to the jelly roll electrode assembly  110 , so that the cooling performance of the jelly roll electrode assembly  110  can be further improved. 
     Referring to  FIG.  6 ( c ) , in the secondary battery according to the present embodiment, a protrusion  135  is formed between the first flow path  130  and the second flow path  140 , and the protrusion  135  may be extended along the first flow path  130 . At this time, the protrusion  135  may be located apart from the second flow path  130 . 
     Thereby, the protrusion  135  has a shape extending along the first flow path  130 , so that the contact area with the fluid flowing between the first flow path  130  and the second flow path  140  can be maximized, and the cooling performance can also be improved accordingly. In addition, the protrusion  135  is formed on the first flow path  130  adjacent to the jelly roll electrode assembly  110 , so that cooling performance for the jelly roll electrode assembly  110  can be further improved. 
     The above-mentioned secondary battery can be applied to various devices. Such a device can be applied to a vehicle means such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present disclosure is not limited thereto, and is applicable to various devices that can use a secondary battery. 
     Although preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements can be made by those skilled in the art using the basic concepts of the present disclosure defined in the appended claims, which also falls under the scope of the present disclosure. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
         
           
               100 : secondary battery 
               110 : jelly roll electrode assembly 
               120 : battery case 
               130 : first flow path 
               140 : second flow path 
               150 : connection part 
               200 : nozzle