BATTERY MODULE HAVING HEAT-SINK STRUCTURE

The invention presents a battery module, which includes a battery holder for accommodating and fixing a plurality of battery cells and a heat-sink structure. The heat-sink structure includes at least one metal plate and at least one heat conductor. The metal plate is configured in a gap between the plurality of battery cells. The heat conductor is configured on the left or right sides of the metal plate, and is an elastic member. When the metal plate is configured in the gap between the battery cells, part of the heat conductor will be compressed by the metal plate and the battery cells, and closely adhere onto the battery cells. When the battery cells are charged and discharged, heat generated by charging and discharging of the battery cells will be conducted to the metal plate through the heat conductors, and then will be taken away through the metal plate.

This non-provisional application claims priority claim under 35 U.S.C. § 119(a) on Taiwan Patent Application No. 111135997 filed Sep. 22, 2022, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a battery module, in particular to a battery module which utilizes a heat-sink structure to take away heat generated by charging and discharging of battery cells and dissipate heat.

BACKGROUND

Referring toFIGS.1,2and3, they are a top sectional view, a front sectional view and a side sectional view of a conventional battery module. As shown inFIGS.1,2and3, a battery module100includes a housing11, a plurality of battery cells12and a battery holder13. The battery holder13includes a first holder131and a second holder132. The battery cells12will be accommodated and fixed between the first holder131and the second holder132. The first holder131and the second holder132for arranging the battery cells12will be placed in the housing11. The battery cells12, the first holder131and the second holder132can be protected through the housing11.

During the charging and discharging process, the battery cells12of the battery module100will generate heat and heat up. In order to enable the heat generated by charging and discharging of the battery cells12to be dissipated, a blowing fan151and an extraction fan153are usually configured on the two sides of the housing11, respectively. The first holder131and the second holder132used for accommodating the battery cells12are configured between the blowing fan151and the extraction fan153. The blowing fan151blows external cold air towards positions where the battery cells12inside the housing11are located. The cold air blown in passes through the battery cells12generating heat and then becomes hot air. Next, the extraction fan153extracts the hot air to exhaust the hot air outwards. Thus, through air blowing of the blowing fan151and hot air extraction of the extraction fan153, it is expected that the battery cells12generating heat by charging and discharging can be cooled.

Also, when the battery cells12of the battery module100are charged and discharged, the center of can body of the battery cells12are hottest points of the whole battery cells12. Moreover, the battery cells12are usually placed in the battery holder13in a parallel arrangement manner. Thus, the hottest points of the battery cells12will be located right in the center of the battery holder13. In other words, when the battery cells12are placed in the battery holder13in the parallel arrangement manner, the hottest point of a battery cell12will exactly correspond to the hottest points of the adjacent battery cells12. Thus, when the battery cell12is at the same temperature as the adjacent battery cells12, the battery cell12will be in an equivalent adiabatic state, and a heat source at the hottest point of the battery cell12will not be able to be dispersed to the adjacent battery cells12. Additionally, the battery holder13is usually made of plastic, and due to extremely poor heat conductivity of the plastic itself, the battery holder13itself cannot conduct the heat out from the battery cells12.

Moreover, the battery cells12are previously parallelly arranged in the long-strip-shaped battery holder13at equal heights. Therefore, most of wind of the cold air blown by the blowing fan151will be blocked by the battery cells12in the front bank that are relatively close to the blowing fan151, resulting in a phenomenon of high flow resistance, and only a small amount of wind can flow to the battery cells12in the rear bank through gaps between the battery cells12in the front bank. Therefore, heat from the battery cells12in the rear bank that are relatively far from the blowing fan will not be easily and effectively brought out.

SUMMARY

An objective of the invention is to provide a battery module, which comprises a plurality of battery cells, a battery holder and a heat-sink structure. The battery holder is configured to accommodate and fix the battery cells. The heat-sink structure includes at least one metal plate and at least one heat conductor. The metal plate is configured in a gap between the plurality of battery cells. The heat conductor is configured on left or right sides of the metal plate and is an elastic member. When the metal plate is configured in the gap between the plurality of battery cells, the heat conductors will be in contact with outer side faces of the center of can body of those battery cells, and part of structure of the heat conductors will be compressed by the metal plate and those battery cells. Part of the structure of the heat conductors compressed will form a contact face having a relatively large area with a battery cell. Therefore, there will be a contact face having a relatively large area between the metal plate and the battery cells through the provision of the heat conductors. When the battery cells are charged and discharged, the heat conductors utilize the contact face having the relatively large area to absorb heat generated by charging and discharging of the battery cells and conduct the absorbed heat to the metal plate. Thus, the metal plate can quickly take the heat away from the battery cells to avoid the battery cells from running in a high-temperature state, thereby reducing the risk of damage to the battery cells.

In order to achieve the above objective, the invention provides a battery module having a heat-sink structure, including a metal housing; a plurality of battery cells; a battery holder, configured to accommodate and fix those battery cells, the battery holder being configured in the metal housing; and the heat-sink structure, including at least one metal plate, configured in a gap between the battery cells or configured in a gap between the battery cells and an inner wall of the metal housing; and at least one heat conductor, configured on left or right sides of the metal plate, wherein the heat conductor is an elastic member, and when the metal plate is configured in the gap between those battery cells or configured in the gap between the battery cells and the inner wall of the metal housing, part of the heat conductor being compressed by the metal plate and the battery cells and closely adhering onto those battery cells.

In an embodiment of the invention, an interior of the metal housing is provided at one side thereof with an air inlet, and provided at other end thereof with an air outlet, and the battery holder is configured between the air inlet and the air outlet.

In an embodiment of the invention, the metal plate is a long-strip-shaped plate body, and two ends of the metal plate are configured towards the air inlet and the air outlet, respectively.

In an embodiment of the invention, one end of the metal plate penetrates out from the battery holder and is connected with a heat-sink fin.

In an embodiment of the invention, the heat-sink fin is configured beside the air inlet or beside the air outlet.

In an embodiment of the invention, the heat conductor is a heat-conducting gap filler, a heat-conducting pad or a heat-conducting tape.

In an embodiment of the invention, the battery holder includes a first holder and a second holder, a lower surface of the first holder includes at least one first positioning slot, an upper surface of the second holder includes at least one second positioning slot, an upper side of the metal plate is embedded and fixed in the first positioning slot of the first holder, and a lower side of the metal plate is embedded and fixed in the second positioning slot of the second holder.

In an embodiment of the invention, the battery module further includes a plurality of fixing elements, the metal plate is provided at an upper side and a lower side thereof with at least one fixing hole, a plate body of the first holder is configured with at least one first penetrating hole, and a plate body of the second holder is configured with at least one second penetrating hole, and each of the fixing elements penetrates through the corresponding first penetrating hole on the first holder or the corresponding second penetrating hole on the second holder so that each of the fixing elements is fixed in the fixing holes on the metal plate, respectively.

In an embodiment of the invention, the metal plate includes a first metal plate unit and two second metal plate units, the first metal plate unit is sandwiched between the two second metal plate units; the first metal plate unit includes a connecting base, the battery cells are jointed with the connecting base of the first metal plate unit through a connector of a conductive connecting element, and therefore are electrically connected together, the first metal plate unit and the second metal plate units are members of different metal materials, and the first metal plate unit and the conductive connecting element are members of the same metal material.

In an embodiment of the invention, each of the battery cells is connected with other battery cell in series through a metallic conductive frame respectively, a negative electrode of one of the battery cells is connected with a system device through a first conducting wire, a positive electrode of one of the battery cells is connected with the connecting base of the metal plate through the connector of the conductive connecting element, the metal plate is connected with the system device through a second conducting wire, and a discharge current flows from the system device to those battery cells connected in series and flows back to the system device through the metal plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS.4,5,6,7A and7B, they are a top perspective view of a battery module according to an embodiment of the invention, a stereo exploded view of part of structure of the battery module according to an embodiment of the invention, a stereo combined view of part of the structure of the battery module according to an embodiment of the invention, and a schematic stereo diagram and schematic front diagram of a heat-sink structure according to an embodiment of the invention, respectively. As shown inFIGS.4,5and6, a battery module200of the present invention includes a metal housing21, a plurality of battery cells22, a battery holder23and at least one heat-sink structure24.

The battery holder23includes a first holder231and a second holder232. The first holder231includes a plurality of sleeves2310, and the second holder232includes a plurality of sleeves2320. An upper end of each of the battery cells22is nested into the sleeve2310of the first holder231, and a lower end of each of the battery cells22is nested into the sleeve2320of the second holder232, so that each of the battery cells22can be fixed between the first holder231and the second holder232and spaced from each other. Moreover, the battery holder23accommodating and fixing the battery cells22will be arranged inside the metal housing21to protect the battery holder23and the battery cells22therein through the metal housing21.

The two sides of the metal housing21are configured with an air inlet211and an air outlet213, respectively. In an embodiment, the air inlet211can be configured with a blowing fan212, and the air outlet213can also be configured with an extraction fan214. The battery holder23is configured between the air inlet211and the air outlet213. Through air blowing of the blowing fan212at the air inlet211and the air extraction of the extraction fan214at the air outlet213, air can be circulated inside the metal housing21.

Each heat-sink structure24includes a metal plate241and at least one heat conductor242. The metal plate241is a long-strip-shaped metal plate body, such as an aluminum plate or a copper plate, and is configured in a gap between the corresponding battery cells22. For example, the metal plate241is configured in a gap between the battery cells22in one row and the battery cells22in other row. In a preferred embodiment of the invention, the two ends of the metal plate241are configured towards the positions of the air inlet211and the air outlet213, respectively. For example, one end (the front end) of the metal plate241faces the air inlet211, and the other end (the rear end) faces the air outlet213. The heat conductor242is an elastic member, such as a heat-conducting gap filler, a heat-conducting pad or a heat-conducting tape and is configured on the left or right sides (e.g., the side faces of two long edges) of the metal plate241in a bonded or a press-fitted manner, as shown inFIGS.7A and7B.

A lower surface of the first holder231includes at least one first positioning slot2311, and an upper surface of the second holder232includes at least one second positioning slot2321. When the metal plate241is assembled with the first holder231and the second holder232, an upper side of the metal plate241is embedded and fixed in the first positioning slot2311of the first holder231, and a lower side of the metal plate241is embedded and fixed in the second positioning slot2321of the second holder232. The metal plate241is positioned in the battery holder23through the positioning slots2311,2321of the holders231,232.

Furthermore, the battery module200further includes a plurality of fixing elements25, such as screws. An upper side and a lower side of the metal plate241are each provided with at least one fixing hole2410, such as a screw hole. A plate body of the first holder231is configured with at least one first penetrating hole2312, and a plate body of the second holder232is configured with at least one second penetrating hole2322. Each of the fixing elements25penetrates through the corresponding first penetrating hole2312on the first holder231or the corresponding second penetrating hole2322on the second holder232respectively and is locked in the fixing hole2410on the metal plate241respectively. Thus, the metal plate241is stably positioned in the battery holder23through locking of the fixing elements25and the fixing holes2410.

When the metal plate241is configured in the gap between the corresponding battery cells22, part of structure of the heat conductors242will be in contact with outer side faces of the center of can body of the battery cells22, and compressed by the metal plate241and the battery cells22and closely adhere onto the battery cells22. As further explained inFIG.8, the thickness of the heat conductor242can be set as 2 mm, and the distance between the battery cells22and the metal plate241is 1 mm. When the metal plate241is configured in the gap between the corresponding battery cells22, the heat conductors242will be in contact with the outer side faces of the center of can body of the battery cells22, and part of the structure of the heat conductors242will be compressed by the metal plate241and the battery cells22to a thickness of 1 mm. Part of the structure of the heat conductors242compressed will form a contact face2421having a relatively large area with the battery cells22. Each contact face2421having the relatively large area will adhere onto areas where the battery cells22are not easy to dissipate heat (e.g., areas of the outer side faces of the center of can body of the battery cells22).

Therefore, there will be a contact face2421having a relatively large area between the metal plate241and the battery cells22through the provision of the heat conductors242. When the battery cells22are charged and discharged, the heat conductors242utilize the contact face2421having the relatively large area to absorb heat generated by charging and discharging of the battery cells22, and conduct the absorbed heat to the metal plate241. After receiving the heat generated by charging and discharging of the battery cells22, the metal plate241conducts the heat to one end at a relatively low temperature close to the air inlet211to enable the heat to be dissipated via wind blown by the blowing fan212at the air inlet211. Therefore, the heat generated by charging and discharging of the battery cells22in the rear row that are away from the air inlet211can be quickly taken away through the heat-sink structure24to avoid the battery cells22in the rear row that are away from the air inlet211from operating in a high-temperature state, thereby reducing the risk of damage to the battery cells22.

As shown inFIGS.9and10, in another embodiment of the invention, one end (e.g., the front end) of the metal plate241penetrates out from the battery holder23and is connected with a heat-sink fin26, and the heat-sink fin26can also select a locking manner to be fixed to one end of the metal plate241and is configured beside the air inlet211. Certainly, in another embodiment of the invention, the other end (e.g., the rear end) of the metal plate241can also penetrates out from the battery holder23and is connected with another heat-sink fin26, and the heat-sink fin26is locked to the other end of the metal plate241and configured beside the air outlet213. Through the provision of the heat-sink fin26, the heat conducted on the metal plate241can be concentrated on the heat-sink fin26and quickly dissipated by blowing wind of the blowing fan212at the air inlet211or dissipated by extracting wind of the extraction fan214at the air outlet213.

Referring toFIG.11, it is a top perspective view of a battery module according to another embodiment of the invention. As shown inFIG.11, according to the embodiment, the metal plate241can be configured in the gap between the battery cells22and the metal housing21, in addition to being configured in the gap between the battery cells22. Thus, the heat conducted on the metal plate241in contact with the metal housing21can be absorbed by the metal housing21or dissipated through the metal housing21.

Referring toFIGS.12,13and14, they are a top perspective view of a battery module according to another embodiment of the invention, a stereo combined view of part of structure of a battery module according to another embodiment of the invention, and a schematic diagram of a circuit path of a discharge current of a battery module according to the invention, respectively. As shown inFIGS.12,13and14, each of the battery cells22is connected with another battery cell22in series through a metallic conductive frame223. A negative electrode of one of the battery cells22of the battery module200is connected with a system device300through a first conducting wire221, and a first metal plate unit2411is connected with the system device300through a second conducting wire222. A positive electrode of one of the battery cells22of the battery module200is connected with the metal plate241through a conductive connecting element224.

In general, the unit price of copper is much higher than that of aluminum, in order to reduce the cost of the heat-sink structures, the metal plates241according to the invention use aluminum plates as a preferred choice. Additionally, the electrical conductivity of copper is superior to that of aluminum, thus connection terminals (e.g., conductive connecting element224, metallic conductive frames223) are usually use copper as main bodies. The chemical properties of aluminum are more active than those of copper. If the conductive connecting element224made of a copper material is directly in butt joint with connecting elements of the metal plates241made of an aluminum material, electrochemical reactions will occur at joints between the conductive connecting element224and the connecting elements of the metal plates241, resulting in corrosion of the connecting elements of the metal plates241. After the connecting elements of the metal plates241are corroded, contact resistance of the joints between the conductive connecting element224and the connecting elements of the metal plates241will be increased, and the increased resistance will generate heat. Over time, the joints between the conductive connecting element224and the connecting elements of the metal plates241is prone to dangerous situations, and even leads to disconnection.

In order to avoid direct butt joint between the copper connecting elements and aluminum connecting elements, the metal plates241of the invention are designed as a three-ply plate structure, which includes a first metal plate unit2411and two second metal plate units2412. The first metal plate unit2411is sandwiched between the two second metal plate units2412. The first metal plate unit2411and the second metal plate units2412are members of different metal materials. For example, the first metal plate unit2411is a plate body made of copper, and the second metal plate units2412are plate bodies made of aluminum. Moreover, the conductive connecting element224and the first metal plate unit2411are members of the same metal material, such as copper. Furthermore, the conductive connecting element224includes a connector2241, and the first metal plate unit2411includes a connecting base2413. The conductive connecting element224and the first metal plate unit2411are joined together through locking of the connector2241and the connecting base2413. As such, the connector2241of the conductive connecting element224of a copper material and the connecting base2413of the first metal plate unit2411of a copper material are jointed together, which can avoid corrosion of a joint between the connector2241and the connecting base2413.

The first metal plate unit2411of the invention is used as a power conductor. When the system device300provides a discharge current ID, the discharge current ID flows to the battery cells22of the battery module200via the first conducting wire221. The discharge current ID flows on the battery cells22connected in series via the metallic conductive frames223. After flowing through the battery cells22connected in series, the discharge current ID flows to the first metal plate units2411via the conductive connecting element224. After flowing through the first metal plate units2411, the discharge current ID flows back to the system device300from the second conducting wire222. Thus, the stability of a power supply loop of the battery module200can be improved by using the first metal plate unit2411having a large area as the power conductor.

The above mentioned is only an embodiment of the invention and is not intended to limit the scope of the implementations of the invention, i.e., all equivalent variations and modifications of the shapes, structures, features and spirits described within the scope of the claims of the invention shall be included within the scope of the claims of the invention.