Patent Publication Number: US-11652258-B2

Title: Battery pack

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Divisional Application of U.S. application Ser. No. 17/040,183, filed Sep. 22, 2020, which is the National Phase Application of PCT/KR2019/015855, filed Nov. 19, 2019, which claims benefit under 35 USC § 119 to KR 10-2018-0144863, filed Nov. 21, 2018, the content of all of which are incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a battery pack. 
     BACKGROUND ART 
     In recent years, with an increase in the demand for portable electronic devices, such as laptop computers, smartphones, and tablet computers, research has been actively conducted on high-performance secondary batteries that are capable of being repeatedly charged and discharged. 
     In addition, secondary batteries have come to be widely used in medium- or large-sized devices, such as vehicles, robots, and satellites, as well as small-sized devices, such as portable electronic devices. In particular, as fossil fuels are being depleted and increasing attention is being paid to environmental pollution, research on hybrid vehicles and electric vehicles is being actively conducted. The most essential part of a hybrid vehicle or an electric vehicle is a battery pack configured to supply electric power to a motor. The battery pack includes a battery module including a plurality of battery cells, wherein the plurality of battery cells is connected to each other in series and/or in parallel, whereby the capacity and output of the battery module are increased. 
     Basically, a battery cell is manufactured through a process of stacking a plurality of electrode plates in the state in which a separator is disposed therebetween and welding a plurality of electrode tabs to the plurality of electrode plates, respectively, to form an electrode assembly and wrapping the electrode assembly in an aluminum pouch so as to be sealed. 
     During the use of the battery pack, gas may be generated in the battery cell. The gas may be generated due to the decomposition of an electrolyte when the lifespan of the battery cell expires, the battery cell is exposed to high temperature, the battery cell is overcharged, or short circuit occurs in the battery cell. The pouch of the battery cell generally has a gas discharge structure configured to prevent the occurrence of a safety-related accident due to the gas generated as described above. 
     However, a conventional battery pack does not have a construction that is capable of immediately confirming the generation of gas in a battery cell. Therefore, there is a need for a construction capable of enabling a user to immediately confirm the generation of gas in the case in which the gas is generated in the battery cell such that the user can take a measure, such as exchange of the battery pack. 
     DISCLOSURE 
     Technical Problem 
     The present invention has been made in view of the above problems, and it is an object of the present invention to provide a battery pack capable of enabling a user to immediately confirm the generation of gas in a battery cell. 
     Technical Solution 
     A battery pack according to an embodiment of the present invention provided to accomplish the above object may include a battery cell, a casing configured to receive the battery cell, the casing having formed therein a vent chamber configured to allow gas generated in the battery cell to be discharged therethrough, and a sound generator installed in the vent chamber so as to block the vent chamber, the sound generator being configured to allow the gas to pass therethrough, the sound generator being configured to generate a sound by the flow of the gas when the gas is discharged from the casing through the vent chamber. 
     The sound generator may include a first portion having at least one first orifice formed at an inlet side of the vent chamber and a second portion disposed so as to be spaced apart from the first portion, a gas diffusion space being formed between the first portion and the second portion, the second portion having at least one second orifice formed at an outlet side of the vent chamber, 
     The sound generator may include a partition wall disposed at the inlet side of the vent chamber, the partition wall having at least one gas passage hole formed therein, and a vibration plate supported by the partition wall, the vibration plate being configured to be vibrated by the flow of gas that has passed through the gas passage hole in order to generate a sound. 
     A collision wall provided at an outlet side of the vent chamber and configured to allow a sound wave of the sound generated by the sound generator to collide therewith. 
     A concave portion configured to reflect a sound wave of the sound generated by the sound generator may be provided at the outlet side of the vent chamber. 
     A moisture blocking membrane may be installed at the inlet side of the vent chamber so as to block the inlet, the moisture blocking membrane being configured to allow the flow of gas into the vent chamber and to block the introduction of moisture into the casing. 
     The casing may include an upper housing and a lower housing, the vent chamber may be formed in the upper housing, and the battery cell may be received in the lower housing. 
     The upper housing may have a gas capture space formed therein, the gas capture space being configured to communicate with the vent chamber and to capture the gas. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The following drawings appended to this specification are provided to illustrate preferred embodiments of the present invention and to aid in understanding the technical idea of the present invention together with the detailed description of the invention, a description of which will follow, and the present invention should not be interpreted as being limited only to matters described in the drawings. 
         FIG.  1    is a perspective view schematically showing a battery pack according to a first embodiment of the present invention. 
         FIG.  2    is a sectional view schematically showing the battery pack according to the first embodiment of the present invention. 
         FIG.  3    is a sectional view schematically showing a sound generator of the battery pack according to the first embodiment of the present invention and the flow of gas passing through the sound generator. 
         FIG.  4    is a sectional view schematically showing a sound generator and a moisture blocking membrane of a battery pack according to a second embodiment of the present invention. 
         FIG.  5    is a sectional view schematically showing a sound generator of a battery pack according to a third embodiment of the present invention and the flow of gas passing through the sound generator. 
     
    
    
     BEST MODE 
     Embodiments of the present invention are provided in order to more completely describe the present invention to a person having ordinary skill in the art, and therefore the shape and size of each element in the drawings may be exaggerated, omitted, or schematically illustrated for clearer description. Consequently, the size or rate of each element does not entirely reflect the actual size or rate thereof. 
     Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that terms or words used in this specification and the claims are not to be interpreted as having ordinary and dictionary-based meanings but as having meanings and concepts coinciding with the technical idea of the present invention based on the principle that the inventors may properly define the concepts of the terms in order to explain the invention in the best method. 
       FIG.  1    is a perspective view schematically showing a battery pack according to a first embodiment of the present invention, and  FIG.  2    is a sectional view schematically showing the battery pack according to the first embodiment of the present invention. 
     As shown in  FIGS.  1  and  2   , the battery pack according to the first embodiment of the present invention includes a casing  100  having an inner space, electrode terminals  210  and  220  exposed outside through through-holes (not shown) formed in the casing  100 , and a battery module disposed in the casing  100 , the battery module having a plurality of battery cells  300 . 
     As shown in  FIG.  1   , the electrode terminals  210  and  220  may be configured so as to be exposed upwards in  FIG.  1   . 
     As shown in  FIG.  1   , the casing  100  may have the shape of an approximately rectangular parallelepiped; however, the present invention is not limited as to the shape of the casing  100 . The casing  100  serves to protect the battery cells  300  from external force. The casing  100  includes an upper housing  110  and a lower housing  120 . The upper housing  110  and the lower housing  120  are coupled to each other such that the inner space, which is configured to receive the battery cells  300 , is formed in the casing  100 . 
     Each of the upper housing  110  and the lower housing  120  may be made of plastic. In this case, the upper housing  110  and the lower housing  120  may be joined to each other by welding. As a result, the interior of the casing  100  may have a dustproof and waterproof structure. However, the present invention is not limited as to the material of each of the upper housing  110  and the lower housing  120 . In addition, the upper housing  110  and the lower housing  120  may be coupled to each other by any of various fastening means, such as bolting and riveting, in place of welding. 
     The plurality of battery cells  300  may be received in the lower housing  120 . For example, each of the battery cells  300  may be a pouch-shaped battery cell, and the pouch-shaped battery cell may include an electrode assembly configured by stacking a plurality of electrode plates in the state in which a separator is disposed therebetween and a pouch configured to wrap the electrode assembly. The lower housing  120  may have a battery cell receiving space having a width and a height corresponding respectively to the width and the length of each of the battery cells  300 . 
     A vent chamber  190  configured to allow gas generated in the battery cells  300  to be discharged therethrough may be formed in the tipper housing  110 . The vent chamber  190  has an inlet  191  configured to allow gas to be introduced therethrough and an outlet  192  configured to allow gas to be discharged therethrough and an inner surface  193 . Consequently, gas generated in the battery cells  300  due to problems with the battery cells  300  may flow from the lower housing  120  to the upper housing  110 , and may be discharged outside through the vent chamber  190  of the upper housing  110  under a predetermined pressure. 
     Meanwhile, the upper housing  110  may have a gas capture space  160  configured to communicate with the vent chamber  190 . Gas generated in the battery cells  300  may be captured in the gas capture space  160 . When the pressure of the gas captured in the gas capture space  160  reaches the predetermined pressure, therefore, the gas may be discharged outside through the vent chamber  190 . 
     As an example, the gas capture space  160  may be located at the middle of the upper part of the casing  100  or may be located at a position biased to one side from a vertical central axis of the casing  100 . Consequently, the gas generated in the battery cells  300  may directly flow to the gas capture space  160  located at the middle of the upper part of the casing  100  (the middle of the upper housing  110 ). In addition, the gas that has flowed to the gas capture space  160  may directly flow toward the vent chamber  190 . 
     The battery pack according to the first embodiment of the present invention may include a sound generator  400  configured to generate a sound such that, in the case in which gas is generated in the battery cells  300 , a user can immediately confirm the same. 
     Hereinafter, the sound generator  400  of the battery pack according to the first embodiment of the present invention will be described with reference to  FIG.  3   .  FIG.  3    is a sectional view schematically showing the sound generator of the battery pack according to the first embodiment of the present invention and the flow of gas passing through the sound generator. 
     As shown in  FIG.  3   , the sound generator  400  may be mounted in the vent chamber  190  of the casing  100  of the battery pack. The sound generator  400  is between the inlet  191  and outlet  192  and the sound generator contacts the inner surface of the chamber and extends between the inlet  191  and outlet  192 . 
     As an example, the sound generator  400  may be configured as a single module, and may be inserted and fitted into the interior of the vent chamber  190  of the casing  100 . The sound generator  400  may have a size corresponding to the size of the inner space of the vent chamber  190 , and therefore the sound generator  400  may be fastened to the interior of the vent chamber  190  in a tight fitting fashion, whereby fastening therebetween may be stably maintained. 
     Alternatively, the sound generator  400  may be fitted into the interior of the vent chamber  190 , and then the sound generator  400  may be stably mounted in the vent chamber  190  by welding, bolting, riveting, an adhesive, etc. 
     Since the sound generator  400  is configured as a single separate module, the sound generator  400  may be fitted into a vent chamber  190  of a battery pack having a conventional structure, and may be used in this state. Consequently, the sound generator  400  may be easily applied to a battery pack having a conventional structure. In this case, a space having a sufficient size to allow the sound generator  400  to pass toward the vent chamber  190  may be secured at the outlet  192  side of the vent chamber  190 . 
     However, the present invention is not limited to the construction in which the sound generator  400  is configured as a separate module. As another example, the sound generator  400  may be formed integrally with the casing  100 . For example, the sound generator  400  may be formed integrally with the casing  100  through injection molding, insert injection molding, etc. 
     The sound generator  400  is installed in the vent chamber  190  so as to block the vent chamber  190 , and is configured to allow gas to pass therethrough. In the process in which gas introduced through the inlet  191  of the vent chamber  190  is discharged through the outlet  192  of the vent chamber  190 , therefore, the gas generates a sound when passing through the sound generator  400 . 
     The sound generator  400  may include a first portion  410  having a first orifice  411  formed at the inlet  191  side of the vent chamber  190  and a second portion  420  disposed so as to be spaced apart from the first portion  410 , a gas diffusion space  430  being formed between the first portion  410  and the second portion  420 , the second portion  420  having a second orifice  421  formed at the outlet  192  side of the vent chamber  190 . 
     Depending on circumstances, the first portion  410  may have a plurality of first orifices  411 . The plurality of first orifices  411  may be disposed about the center of the inlet  191  of the vent chamber  190  at regular intervals in the circumferential direction thereof. In the same manner, the second portion  420  may have a plurality of second orifices  421 . The plurality of second orifices  421  may be disposed about the center of the outlet  192  of the vent chamber  190  at regular intervals in the circumferential direction thereof. 
     In order to effectively generate a swirl of gas, the inner diameter of the first orifice  411  may be gradually increased from the inlet  191  of the vent chamber  190  in a direction toward the gas diffusion space  430 . However, the present invention is not limited to this construction, and the first orifice  411  may have a uniform inner diameter. In the same manner, in order to effectively generate a swirl of gas, the inner diameter of the second orifice  421  may be gradually increased from the gas diffusion space  430  in a direction toward the outlet  192  of the vent chamber  190 . However, the present invention is not limited to this construction, and the second orifice  421  may have a uniform inner diameter. 
     According to this construction, gas introduced through the inlet  191  of the vent chamber  190  pushes the first portion  410  of the sound generator  400 , whereby pressure of the gas increases. 
     When the pressure of the gas introduced through the inlet  191  of the vent chamber  190  reaches a predetermined pressure, some of the gas that pushes the first portion  410  passes through the first orifice  411  and is then ejected into the gas diffusion space  430 . 
     At this time, the gas ejected into the gas diffusion space  430  generates a swirl while flowing very unstable. In addition, the gas ejected into the gas diffusion space  430  collides with the second portion  420 . Consequently, a sound wave is generated due to the swirl of the gas and the collision of the gas with the second portion  420 . 
     In addition, some of the gas in the gas diffusion space  430  generates a swirl when passing through the second orifice  421  of the second portion  420  and being ejected outside, and a sound wave is generated due to this swirl. 
     The sound wave generated by ejection of the gas as described above is transmitted to a user, whereby it is possible for the user to immediately confirm the situation in which the gas is ejected through the outlet  192  of the vent chamber  190 . 
     Meanwhile, a collision wall  180  installed at a position of the upper housing so as to be spaced apart from outlet of the vent chamber and the sound generator  400  and configured to allow the sound wave of the sound generated by the sound generator  400  to collide therewith may be provided at the outlet  192  side of the vent chamber  190 . The collision wall  180  may serve to reflect the sound wave toward a position at which the user is capable of clearly hearing the sound. 
     The collision wall  180  may be formed in the tipper housing  110  at a position adjacent to the outlet  192  side of the vent chamber  190 . As seen in  FIG.  4   , the collision wall is parallel to the second portion having the second orifice  421 . However, the present invention is not limited to this construction, and the collision wall  180  may be formed integrally with the sound generator  400 . Consequently, the sound generator  400  may be configured as a single module including the collision wall  180 , and may be mounted in the vent chamber  190 . 
     In addition, a concave portion  170  configured to reflect the sound wave of the sound generated by the sound generator  400  may be further provided at the outlet  192  side of the vent chamber  190 . The concave portion in formed in a portion of the upper housing extending from a first position of the tipper housing having the outlet  192  of the vent chamber and a second position of the upper housing having the collision wall  180 . In the same manner as the collision wall  180 , the concave portion  170  may serve to reflect the sound wave toward a position at which the user is capable of clearly hearing the sound. 
     The concave portion  170  may have a curved surface formed to induce smooth reflection of the sound wave discharged through the outlet  192  of the vent chamber  190 . In addition, the curved surface of the concave portion  170  may be curved toward the collision wall  180 . Meanwhile, the collision wall  180 , the concave portion  170 , the outlet  192  of the vent chamber  190 , and the second portion  420  of the sound generator  400  form a space having the shape of a predetermined bowl thereamong. This space may serve to reflect the sound wave toward a position at which the user is capable of clearly hearing the sound. 
     The concave portion  170  may be formed in the upper housing  110  at a position adjacent to the outlet  192  side of the vent chamber  190 . However, the present invention is not limited to this construction, and the concave portion  170  may be formed integrally with the sound generator  400 . Consequently, the sound generator  400  may be configured as a single module including the concave portion  170 , and may be mounted in the vent chamber  190 . 
     The battery pack according to the first embodiment of the present invention includes the sound generator  400 , which is configured to generate a sound by the flow of gas generated in the battery cells  300 . In the case in which gas is generated in the battery cells  300 , therefore, it is possible for the user to immediately confirm the same. 
     In addition, according to the first embodiment of the present invention, the sound generator  400  of the battery pack is configured to generate a sound only by the flow of gas. Consequently, it is possible for the user to confirm the generation of gas without additional electric power or power or without a separate sensor. 
     Hereinafter, a battery pack according to a second embodiment of the present invention will be described with reference to  FIG.  4   . Components identical to the components of the first embodiment of the present invention are denoted by the same reference numerals, and a detailed description thereof will be omitted. 
       FIG.  4    is a sectional view schematically showing a sound generator and a moisture blocking membrane of a battery pack according to a second embodiment of the present invention. 
     As shown in  FIG.  4   , the battery pack according to the second embodiment of the present invention may have a moisture blocking membrane  500  installed at an inlet  191  side of a vent chamber  190  so as to block the inlet  191  and configured to allow the flow of gas into the vent chamber  190  and to block the introduction of moisture into a casing  100 . 
     The moisture blocking membrane  500  is located between a gas capture space  160  and the vent chamber  190  to partition the gas capture space  160  and the vent chamber  190  from each other. The moisture blocking membrane  500  may be fixedly coupled to the inlet  191  of the vent chamber  190  through various fastening means, such as welding, bolting, riveting, and an adhesive. 
     The moisture blocking membrane  500  is configured to allow gas having a predetermined pressure to pass therethrough. When the pressure of gas captured in the gas capture space  160  reaches the predetermined pressure, therefore, the gas present in the gas capture space  160  may flow into the vent chamber  190  through the moisture blocking membrane  500 , and may generate a sound while passing through a sound generator  400 . 
     In the battery pack according to the second embodiment of the present invention, the moisture blocking membrane  500  is provided between the gas capture space  160  and the vent chamber  190 , whereby it is possible to prevent moisture from being introduced into the casing  100 . In addition, the gas may be discharged outside through the vent chamber  190  only when the pressure of the gas in the casing  100  reaches the predetermined pressure. 
     Hereinafter, a battery pack according to a third embodiment of the present invention will be described with reference to  FIG.  5   . Components identical to the components of the first and second embodiments of the present invention are denoted by the same reference numerals, and a detailed description thereof will be omitted. 
       FIG.  5    is a sectional view schematically showing a sound generator of a battery pack according to a third embodiment of the present invention and the flow of gas passing through the sound generator. 
     As shown in  FIG.  5   , the battery pack according to the third embodiment of the present invention may include a sound generator  600 , and the sound generator  600  may include a partition wall  610  disposed at an inlet  191  side of a vent chamber  190 , the partition wall  610  having a gas passage hole  611  formed therein, and a vibration plate  620  supported by the partition wall  610 , the vibration plate  620  being configured to be vibrated by the flow of gas that has passed through the gas passage hole  611  in order to generate a sound. The inlet  191  and outlet  192  of the vent chamber are spaced from one another in a first direction. The partition wall  610  and vibration plate have a width in a second direction different than the first direction. The width of the vibration plate  620  is less than a width of the partition wall  610 . The edges of the partition wall are retained by a support  195  fitting against the inner surface  193  of the vent chamber. The edges of the vibration plate  620  are spaced from the support  195 . 
     As an example, the sound generator  600  may be configured as a single module, and may be inserted and fitted into the interior of the vent chamber  190 , which is formed in a casing  100 . The sound generator  600  may have a size corresponding to the size of an inner space of the vent chamber  190 , and therefore the sound generator  600  may be fastened to the interior of the vent chamber  190  in a tight fitting fashion, whereby fastening therebetween may be stably maintained. 
     Alternatively, the sound generator  600  may be fitted into the interior of the vent chamber  190 , and then the sound generator  600  may be stably mounted in the vent chamber  190  by welding, bolting, riveting, an adhesive, etc. 
     Since the sound generator  600  is configured as a single separate module, the sound generator  600  may be fitted into a vent chamber  190  of a battery pack having a conventional structure, and may be used in this state. Consequently, the sound generator  600  may be easily applied to a battery pack having a conventional structure. In this case, a space having a sufficient size to allow the sound generator  600  to pass toward the vent chamber  190  may be secured at an outlet  192  side of the vent chamber  190 . 
     However, the present invention is not limited to the construction in which the sound generator  600  is configured as a separate module. As another example, the sound generator  600  may be formed integrally with the casing  100 . For example, the sound generator  600  may be formed integrally with the casing  100  through injection molding, insert injection molding, etc. 
     The partition wall  610  may have a plurality of gas passage holes  611 . The plurality of gas passage holes  611  may be disposed at regular intervals in the circumferential direction of the vibration plate  620 . 
     The vibration plate  620  may be made of plastic or metal that exhibits predetermined flexibility. The center of the vibration plate  620  may be fixed to the center of the partition wall  610  via a connection member having the shape of a predetermined bar. 
     According to this construction, gas introduced through the inlet  191  of the vent chamber  190  pushes the partition wall  610  of the sound generator  600 , whereby pressure of the gas increases. At this time, some of the gas that pushes the partition wall  610  passes through the gas passage holes  611 , and is then ejected toward the vibration plate  620 . As a result, the vibration plate  620  may be vibrated by the ejected gas, and may vibrate ambient air to generate a sound wave. 
     According to the third embodiment of the present invention, the sound generator  600  of the battery pack is configured to generate a sound only by the flow of gas. Consequently, it is possible for the user to confirm the generation of gas without additional electric power or power or without a separate sensor. 
     The battery pack according to the embodiment of the present invention may be applied to a device including the battery pack as a power source. 
     For example, the device may be a computer, a cellular phone, a wearable electronic device, a power tool, an electric vehicle (EV), a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric two-wheeled vehicle, an electric golf cart, or an energy storage apparatus. The energy storage apparatus may be applied to various fields or places, such as a smart-grid system configured to control the supply and demand of electric power or a charging station for electric vehicles. 
     The preferred embodiments of the present invention have been described illustratively; however, the scope of the present invention is not limited to such specific embodiments, and may be appropriately changed within the category described in the claims. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
         
           
               100 : Casing 
               300 : Battery cells 
               400 : Sound generator 
               500 : Moisture blocking membrane 
               600 : Sound generator 
           
         
       
    
     INDUSTRIAL APPLICABILITY 
     A battery pack according to an embodiment of the present invention includes a sound generator configured to generate a sound by the flow of gas generated in a battery cell. In the case in which gas is generated in the battery cell, therefore, it is possible for a user to immediately confirm the same. 
     According to the embodiment of the present invention, the sound generator of the battery pack is configured to generate a sound only by the flow of gas. Consequently, it is possible for the user to confirm the generation of gas without additional electric power or power or without a separate sensor.