Battery pack with improved fast charging capabilities

Abstract

A battery pack according to an embodiment of the present invention includes a first battery and a second battery, a connector unit including an electrode terminal and a communication terminal and configured to be connectable to an external device, and a BMS configured to determine whether the connector unit is connected to the external device and control an electrical connection relationship between the first battery, the second battery, and the external device according to the external device connected to the connector unit.

Description

Technical Field

[0001] The present invention relates to a battery pack, and more particularly to a battery pack with improved rapid charging function.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0065676 filed on May 27, 2022, and all of the content disclosed in the specification and drawings of the application is incorporated into this application.

Background Art

[0003] Recently, the demand for portable electronic products such as notebook PCs, video cameras, mobile phones, etc. has increased rapidly. As the development of electric vehicles, energy storage batteries, robots, satellites, etc. becomes full-scale, research on high-performance batteries capable of repeated charging and discharging is actively underway.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium batteries, etc. Among these, lithium batteries have attracted attention due to advantages such as almost no memory effect compared to nickel-based batteries, free charging and discharging, very low self-discharge rate, and high energy density.

[0005] In recent years, as the number of users of electric vehicles increases, the demand for rapid charging of the batteries included in electric vehicles has been increasing. For example, in order to achieve rapid charging within 15 minutes, a current of 4C (C-rate) or more must be applied. However, since mass-produced batteries for electric vehicles are graphite-based batteries, there is a problem that lithium plating may occur when a high current of 4C or more is applied.

[0006] It should be noted that there seems to be a formatting issue with the tag

[0003] in the original text where it is not properly aligned with the other tags in the list. I've translated it as is while maintaining the overall structure. If this is a specific formatting requirement that needs to be corrected, please provide more context or clarify the issue.Here, lithium plating (Li-plating) is a phenomenon in which lithium metal is deposited on the surface of the negative electrode. Lithium plating can cause side reactions with the electrolyte and / or deformation of the battery's kinetic balance, leading to battery degradation. Furthermore, the deposition of lithium metal on the negative electrode surface can cause an internal short circuit in the battery, posing a risk of fire and explosion due to the short circuit.

[0007] Therefore, there is a need to develop battery packs that prevent lithium plating and enable rapid charging. [Overview of the project] [Problems that the invention aims to solve]

[0008] This invention has been made in view of the above-mentioned problems, and aims to provide a battery pack with improved rapid charging capabilities.

[0009] Other objects and advantages of the present invention can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0010] A battery pack according to one aspect of the present invention may include a first battery and a second battery; a connector portion including electrode terminals and communication terminals, configured to be connectable to an external device; and a BMS configured to determine whether or not the connector portion is connected to the external device, and to control the electrical connection relationship between the first battery, the second battery and the external device according to the external device connected to the connector portion.

[0011] The BMS may be configured to receive information related to the charging type from the charger when a charger is connected as an external device to the connector, and to connect at least one of the first battery and the second battery to the charger according to the charging type.

[0012] The BMS may be configured to connect the first battery and the second battery to the charger when the charging type is slow charging.

[0013] The BMS may be configured to connect the second battery to the charger and disconnect the connection between the first battery and the charger when the charging type is fast charging.

[0014] The BMS may be configured to change the charging type to slow charging after the rapid charging of the second battery is completed, and then connect the first battery and the charger.

[0015] The BMS may be configured to connect the first battery to the load and disconnect the second battery from the load when a load is connected to the connector as an external device.

[0016] The BMS may be configured to measure the voltage of the first battery connected to the load and to control the connection between the first battery, the second battery, and the load based on the voltage of the first battery.

[0017] The BMS may be configured to connect the second battery to the load and disconnect the connection between the first battery and the load when the voltage of the first battery is below a preset critical voltage.

[0018] The BMS may be configured to measure the voltage of the second battery and, if the voltages of the first battery and the second battery are the same, to further connect the first battery to the load.

[0019] In addition, the battery pack according to another aspect of the present invention may further include a first relay connected between the first battery and the electrode terminal and configured to electrically connect or disconnect the first battery and the electrode terminal according to a controlled operating state, and a second relay connected between the second battery and the electrode terminal and configured to electrically connect or disconnect the second battery and the electrode terminal according to a controlled operating state.

[0020] The BMS may be configured to control the connection relationship between the first battery, the second battery, and the external device by controlling the operating states of the first relay and the second relay.

[0021] The first battery and the second battery may be configured to have different negative electrode active materials.

[0022] An automobile according to still another aspect of the present invention may include the battery pack according to one aspect of the present invention.

Advantages of the Invention

[0023] According to one aspect of the present invention, there is an advantage that generation of lithium plating can be prevented and a battery pack capable of rapid charging can be provided.

[0024] The effects of the present invention are not limited to the effects described above, and other effects of the present invention not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention. Therefore, the present invention should not be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0026] [Figure 1]It is a diagram schematically showing a battery pack according to an embodiment of the present invention. [Figure 2] It is a diagram schematically showing the configuration of a battery pack according to an embodiment of the present invention. [Figure 3] It is a diagram schematically showing the charging process of a battery pack according to an embodiment of the present invention. [Figure 4] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention is slowly charged. [Figure 5] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention is slowly charged. [Figure 6] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention is rapidly charged. [Figure 7] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention is rapidly charged. [Figure 8] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention is rapidly charged. [Figure 9] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention discharges. [Figure 10] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention discharges. [Figure 11] It is a diagram schematically showing an example in which a battery pack according to an embodiment of the present invention discharges. [Figure 12] It is a diagram schematically showing another example in which a battery pack according to an embodiment of the present invention discharges. [Figure 13] It is a diagram schematically showing another example in which a battery pack according to an embodiment of the present invention discharges. [Figure 14] It is a schematic diagram schematically showing the state of an automobile according to another embodiment of the present invention.

Modes for Carrying Out the Invention

[0027] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner and concept appropriate to the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention.

[0028] Therefore, it should be understood that the embodiments and configurations shown in the drawings described herein represent only one of the most preferred embodiments of the present invention and do not represent the entirety of the technical concept of the present invention, and that there are various equivalents and modifications that can be substituted for them at the time of this application.

[0029] Furthermore, if a specific description of a known function or configuration related to the present invention is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0030] Terms that include ordinal numbers, such as "first," "second," etc., are used to distinguish one of several components from the rest, and do not mean that such terms limit the components.

[0031] Furthermore, throughout the specification, when a part of it "includes" a certain component, unless otherwise specified, this does not mean that other components are excluded, but rather that other components may be included.

[0032] Furthermore, when a part of the specification is described as being "connected" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly connected" through other elements in between.

[0033] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0034] Figure 1 is a schematic diagram showing a battery pack 100 according to one embodiment of the present invention. Figure 2 is a schematic diagram showing the configuration of the battery pack 100 according to one embodiment of the present invention.

[0035] Referring to Figure 1, the battery pack 100 may include a first battery 110, a second battery 120, a connector section 130, and a BMS (Battery Management System) 140.

[0036] Here, "battery" refers to a single, independent cell that has a negative terminal and a positive terminal and is physically separable. For example, a lithium-ion battery or a lithium polymer battery may be considered a battery. Alternatively, a battery may refer to a battery module in which multiple cells are connected in series and / or parallel.

[0037] In the embodiment shown in Figure 2, the battery pack 100 may be equipped with a first battery 110 and a second battery 120. The positive terminals of the first battery 110 and the second battery 120 may be connected to the positive terminal P+ of the battery pack 100. The negative terminals of the first battery 110 and the second battery 120 may be connected to the negative terminal P- of the battery pack 100.

[0038] The connector section 130 includes electrode terminals P+ and P- and a communication terminal CT, and can be configured to be connectable to an external device 200.

[0039] For example, the electrode terminals may include the positive terminal P+ and negative terminal P- of the battery pack 100. The electrode terminals may be connected to an external device 200 to form a power line. The communication terminal CT may form a communication line with the external device 200 connected to the battery pack 100.

[0040] In the embodiment shown in Figure 2, the battery pack 100 can be connected to an external device 200. In this case, the electrode terminals can be connected to external electrode terminals provided on the external device 200. The communication terminals can be connected to external communication terminals provided on the external device 200.

[0041] The BMS140 may be configured to determine whether or not a connection is made between the connector section 130 and the external device 200.

[0042] For example, the BMS 140 can be connected to the communication terminal CT of the connector unit 130. The BMS 140 can then communicate with the external device 200 via the communication line formed by the connection between the communication terminal CT of the connector unit 130 and the external communication terminal of the external device 200. In other words, the BMS 140 can determine whether or not the connector unit 130 is connected to the external device 200 by communicating with the external device 200 via the communication line.

[0043] In another example, the BMS 140 may determine whether or not a connection is made between the connector 130 and the external device 200 based on a change in at least one of the voltage, current, and resistance of the power line formed by the connection between the electrode terminals of the connector 130 and the external electrode terminals of the external device 200.

[0044] Preferably, the BMS 140 can determine not only whether the connector section 130 is connected to the external device 200, but also the type of external device 200 connected to the connector section 130. For example, the BMS 140 can determine that the external device 200 connected to the connector section 130 is either a charger 210 or a load 220. Here, the charger 210 is a device that can charge the battery pack 100 by applying a charging current from the battery pack 100. The load 220 is a device that can discharge the battery pack 100 by receiving a discharge current from the battery pack 100.

[0045] The BMS140 may be configured to control the electrical connection relationship between the first battery 110 and the second battery 120 and the external device 200 in accordance with the external device 200 connected to the connector portion 130.

[0046] Specifically, when an external device 200 is connected to the connector 130, the BMS 140 can control the electrical connection relationship between the first battery 110 and the second battery 120 and the external device 200 based on the type of external device 200.

[0047] For example, the BMS 140 can connect the first battery 110 to the external device 200 and disconnect the second battery 120 from the external device 200. In the embodiment shown in Figure 2, the BMS 140 can control the operating state of the first relay 150 to the turn-on state and the operating state of the second relay 160 to the turn-off state.

[0048] In another example, the BMS 140 can connect the second battery 120 to the external device 200 and disconnect the first battery 110 from the external device 200. In the embodiment shown in Figure 2, the BMS 140 can control the operating state of the first relay 150 to the turn-off state and the operating state of the second relay 160 to the turn-on state.

[0049] In other words, the BMS140 has the advantage of being able to selectively configure the electrical connection relationship between the batteries 110 and 120 provided in the battery pack 100 and the external device 200, based on whether or not the external device 200 is connected to the battery pack 100.

[0050] Referring further to Figure 1, the battery pack 100 may further include a first relay 150 and a second relay 160.

[0051] The first relay 150 is connected between the first battery 110 and the electrode terminals and may be configured to electrically connect or disconnect the first battery 110 and the electrode terminals depending on the controlled operating state.

[0052] In the embodiment shown in Figure 2, when the operating state of the first relay 150 is in the turn-on state, the first battery 110 and the external device 200 can be electrically connected. Conversely, when the operating state of the first relay 150 is in the turn-off state, the electrical connection between the first battery 110 and the external device 200 can be disconnected.

[0053] The second relay 160 is connected between the second battery 120 and the electrode terminals and may be configured to electrically connect or disconnect the second battery 120 and the electrode terminals depending on the controlled operating state.

[0054] In the embodiment shown in Figure 2, when the operating state of the second relay 160 is in the turn-on state, the second battery 120 and the external device 200 can be electrically connected. Conversely, when the operating state of the second relay 160 is in the turn-off state, the electrical connection between the second battery 120 and the external device 200 can be disconnected.

[0055] Furthermore, the BMS140 may be configured to control the connection relationship between the first battery 110 and the second battery 120 and the external device 200 by controlling the operating states of the first relay 150 and the second relay 160.

[0056] Specifically, the BMS 140 can control the operating states of the first relay 150 and the second relay 160, taking into consideration the type of external device 200 (for example, a charger 210 or a load 220) and the voltage of the first battery 110.

[0057] On the other hand, the first battery 110 and the second battery 120 may be configured to have different negative electrode active materials.

[0058] Specifically, the first battery 110 may be a graphite-based battery, and the second battery 120 may be a silicon (Si)-based battery.

[0059] For example, the negative electrode active material of the first battery 110 may be 100% graphite, a mixture of graphite and silicon compounds (e.g., SiO and / or SiC), or a mixture of graphite and silicon.

[0060] For example, the negative electrode active material of the second battery 120 may be 100% silicon, a mixture of silicon and a silicon compound (e.g., SiO and / or SiC), or a mixture of silicon and graphite.

[0061] Here, if the negative electrode active materials of both the first battery 110 and the second battery 120 are mixtures of graphite and silicon, there may be a considerable difference in the specific gravity of graphite between the negative electrode active materials of the first battery 110 and the second battery 120. That is, the negative electrode active material of the first battery 110 may be a mixture of a large amount of graphite and a small amount of silicon. Conversely, the negative electrode active material of the second battery 120 may be a mixture of a large amount of silicon and a small amount of graphite.

[0062] Normally, when a charging current of 4C or more is applied to graphite-based batteries for rapid charging, the likelihood of lithium plating increases significantly. On the other hand, silicon-based batteries have the advantage of a significantly lower likelihood of lithium plating compared to graphite-based batteries, even when a charging current of 4C or more is applied for rapid charging. This is because silicon-based batteries have a high energy density and are non-directional, so even when rapid charging is performed, the likelihood of lithium plating is significantly lower compared to graphite-based batteries.

[0063] In contrast, graphite-based batteries have far superior charge-discharge lifespan characteristics compared to silicon-based batteries, which is why silicon-based batteries are not typically used alone. For example, when both graphite-based and silicon-based batteries are charged and discharged slowly, the graphite-based battery degrades less rapidly than the silicon-based battery. This is because silicon-based batteries are more resistant to rapid charging than graphite-based batteries, but their charge-discharge lifespan characteristics are not as good.

[0064] Therefore, the battery pack 100 according to one embodiment of the present invention has the advantage of improving the rapid charging performance and lifespan of the battery pack 100 by including a graphite-based first battery 110 and a silicon-based second battery 120.

[0065] On the other hand, the BMS140 may selectively include processors, ASICs (application-specific integrated circuits), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the industry, to execute the various control logics performed in the present invention. Furthermore, when the control logic is embodied as software, the BMS140 may be embodied by a collection of program modules. In this case, the program modules are stored in memory and can be executed by the BMS140. The memory may reside inside or outside the BMS140 and may be connected to the BMS140 by various known means.

[0066] For example, the type of memory is not particularly limited, as long as it is a known means of storing information from which data can be recorded, erased, updated, and read. Examples of such means of storing information include RAM, flash memory (registered trademark), ROM, EEPROM, and registers.

[0067] Figure 3 is a schematic diagram showing the charging process of a battery pack 100 according to one embodiment of the present invention. Figures 4 and 5 are schematic diagrams showing an embodiment in which the battery pack 100 according to one embodiment of the present invention is slowly charged. Figures 6 to 8 are schematic diagrams showing an embodiment in which the battery pack 100 according to one embodiment of the present invention is rapidly charged.

[0068] Step S310 is the step of determining whether or not to connect the connector part 130 and the charger 210, and can be performed by the BMS 140. If the charger 210 is connected to the connector part 130 in step S310, the process proceeds to step S320; if the charger 210 is not connected to the connector part 130, step S310 may be performed again.

[0069] The BMS140 can determine whether or not the connector section 130 is connected to the charger 210, which is an external device 200. If the charger 210 is connected to the connector section 130, the BMS140 may be configured to receive information related to the charging type from the charger 210.

[0070] Here, the charging type can be slow charging or fast charging. Slow charging and fast charging can be distinguished by a pre-set C-RATE. For example, slow charging may be set with a target charging time of approximately 4 to 5 hours, while fast charging may be set with a target charging time of approximately 15 to 30 minutes.

[0071] Specifically, when the charger 210 is connected to the connector 130, the BMS 140 and the charger 210 can communicate via the communication terminal CT of the connector 130. For example, the BMS 140 and the charger 210 can communicate using PLC (Power Line Communication) technology. The BMS 140 can receive information related to the charging type from the charger 210.

[0072] Step S320 is the step of determining the charging type of the charger 210 connected to the connector 130, and may be performed by the BMS 140. If the charging type in step S320 is slow charging, the process may proceed to step S330; if the charging type is fast charging, the process may proceed to step S340.

[0073] Referring to steps S330 and S340, the BMS 140 may be configured to connect at least one of the first battery 110 and the second battery 120 to the charger 210, depending on the charging type.

[0074] Specifically, the BMS 140 may be configured to select either the first battery 110 and the second battery 120, or the second battery 120, as the battery to be charged, depending on the charging type. The BMS 140 may also be configured to connect the battery to be charged to the charger 210, and to disconnect the remaining unselected batteries from the charger 210.

[0075] Step S330 is the step of connecting the first battery 110 and the second battery 120 to the charger 210 when the charging type is slow charging, and this can be performed by the BMS 140.

[0076] Specifically, if the charging type is slow charging, the BMS 140 may be configured to connect both the first battery 110 and the second battery 120 to the charger 210. That is, if the charging type is slow charging, both the first battery 110 and the second battery 120 may be selected as batteries to be charged.

[0077] For example, in the embodiment shown in Figure 4, if the charging type of the charger 210 is slow charging, the charger 210 can be connected to the first battery 110 and the second battery 120.

[0078] For example, in the embodiment shown in Figure 5, if the charging type of the charger 210 is slow charging, the BMS 140 can select the first battery 110 and the second battery 120 as the batteries to be charged. The BMS 140 can then control the operating state of the first relay 150 to the turn-on state in order to connect the first battery 110 to the charger 210. The BMS 140 can then control the operating state of the second relay 160 to the turn-on state in order to connect the second battery 120 to the charger 210.

[0079] In other words, when the charging type is slow charging, there is no risk of the first battery 110 and the second battery 120 degrading due to charging, so the BMS 140 can control the operating state of both the first relay 150 and the second relay 160 to the turn-on state. Therefore, the first battery 110 and the second battery 120 can be charged together by the charger 210.

[0080] Stage S340 is the stage in which the second battery 120 and the charger 210 are connected when the charging type is fast charging, and this can be performed by the BMS 140. The BMS 140 can also disconnect the connection between the first battery 110 and the charger 210.

[0081] Specifically, if the charging type is fast charging, the BMS 140 may be configured to connect the second battery 120 to the charger 210 and disconnect the connection between the first battery 110 and the charger 210.

[0082] In the embodiment shown in Figure 6, if the charging type of the charger 210 is fast charging, the charger 210 and the second battery 120 can be connected. Here, the connection between the first battery 110 and the charger 210 is disconnected.

[0083] In the embodiment shown in Figure 7, if the charging type of the charger 210 is rapid charging, the BMS 140 may select the second battery 120 as the battery to be charged. The BMS 140 may then control the operating state of the second relay 160 to the turn-on state in order to connect the second battery 120 to the charger 210. The BMS 140 may then control the operating state of the first relay 150 to the turn-off state in order to disconnect the connection between the first battery 110 and the charger 210.

[0084] Stage S350 is the stage of connecting the first battery 110 and the charger 210, which can be performed by the BMS 140.

[0085] Specifically, the BMS 140 may be configured to change the charging type to slow charging after the rapid charging of the second battery 120 is completed. For example, the BMS 140 may request a change in the charging type from the charger 210 via the communication terminal CT.

[0086] The BMS 140 can connect the first battery 110 to the charger 210. Preferably, the BMS 140 can disconnect the second battery 120 from the charger 210.

[0087] For example, in the embodiment shown in Figure 8, the second battery 120, which has completed rapid charging, is disconnected from the charger 210, while the first battery 110, which requires slow charging, can be connected to the charger 210. That is, the BMS 140 can control the operating state of the second relay 160 to the turn-off state and the operating state of the first relay 150 to the turn-on state.

[0088] Therefore, in one embodiment of the present invention, the battery pack 100 allows the second battery 120, which is resistant to rapid charging (less prone to degradation due to rapid charging), to be charged rapidly, while the first battery 110, which is not resistant to rapid charging (more prone to degradation due to rapid charging), can be charged slowly. In other words, relay control by the BMS 140 included in the battery pack 100 makes it possible for both the first battery 110 and the second battery 120, which have different characteristics, to be charged quickly. Furthermore, since degradation of the first battery 110 is prevented during the charging process, there is the advantage that the lifespan of the first battery 110 is ultimately increased.

[0089] Figures 9 to 11 schematically illustrate one embodiment of the discharge of a battery pack 100 according to one embodiment of the present invention. Specifically, Figure 9 schematically illustrates the discharge process of the battery pack 100. Figures 10 and 11 schematically illustrate an exemplary configuration of the battery pack 100 during the discharge process.

[0090] Step S810 is the step of determining whether or not the connector part 130 and the load 220 are connected, and this can be performed by the BMS 140. If the load 220 is connected to the connector part 130 in step S810, the process proceeds to step S820; if the load 220 is not connected to the connector part 130, step S810 may be performed again.

[0091] For example, in the embodiment shown in Figure 10, the BMS 140 can be connected to the load 220 via the communication terminal CT. The BMS 140 can then determine whether or not the connector 130 is connected to the load 220 through communication with the load 220.

[0092] Stage S820 is the stage in which the first battery 110 and the load 220 are connected when the load 220 is connected to the connector 130, and this can be performed by the BMS 140.

[0093] Specifically, when a load 220 is connected to the connector 130 as an external device 200, the BMS 140 may be configured to connect the first battery 110 to the load 220 and disconnect the connection between the second battery 120 and the load 220.

[0094] For example, in the embodiment shown in Figure 10, the BMS 140 can control the operating state of the first relay 150 to a turn-on state in order to connect the first battery 110 to the load 220. The BMS 140 can also control the operating state of the second relay 160 to a turn-off state in order to disconnect the connection between the second battery 120 and the load 220.

[0095] Step S830 is a step in which the voltage of the first battery 110 is measured, which may be performed by the BMS 140.

[0096] Specifically, the BMS 140 may be configured to measure the voltage of the first battery 110. The BMS 140 may also be configured to control the connection between the first battery 110 and the second battery 120 and the load 220 based on the voltage of the first battery 110.

[0097] In the embodiment shown in Figure 10, the BMS 140 may be connected to the first battery 110 and the second battery 120 via a sensing line SL. The BMS 140 can then measure the current, voltage, and temperature of the first battery 110 and the second battery 120 via the sensing line SL. In Figure 10, the BMS 140 and the sensing line SL are simply illustrated, but the measurement units included in the BMS 140 (e.g., including a voltage sensor, a current sensor, and a temperature sensor) can measure the current, voltage, and temperature of the first battery 110 and the second battery 120 via the sensing line SL.

[0098] Stage S840 is a stage in which the voltage of the first battery 110 is compared with the critical voltage, and this can be performed by the BMS 140. If the voltage of the first battery 110 is less than the critical voltage in stage S840, the process proceeds to stage S850, and if the voltage of the first battery 110 is equal to or greater than the critical voltage, stage S830 may be performed further.

[0099] Here, the critical voltage is the voltage at which the first battery 110 is required to be charged, and can be set in advance. That is, the critical voltage can be set in advance to the voltage at which charging is required in order to prevent the first battery 110 from rapidly degrading. Such a critical voltage can be set to correspond to the type of first battery 110 and can be set theoretically or experimentally.

[0100] Stage S850 is the stage in which the second battery 120 and the load 220 are connected, and this can be performed by the BMS 140.

[0101] Specifically, the BMS 140 may be configured to connect the second battery 120 and the load 220 when the voltage of the first battery 110 is below a preset critical voltage. Preferably, the BMS 140 may be configured to disconnect the connection between the first battery 110 and the load 220 to prevent the first battery 110 from being discharged any further.

[0102] For example, in the embodiment shown in Figure 11, the BMS 140 can connect the load 220 and the second battery 120 by controlling the operating state of the second relay 160 to the turn-on state. The BMS 140 can then disconnect the connection between the load 220 and the first battery 110 by controlling the operating state of the first relay 150 to the turn-off state. In this case, the first battery 110 will not discharge any further, thus preventing deterioration of the first battery 110.

[0103] In other words, the battery pack 100 according to one embodiment of the present invention can prevent the deterioration of the first battery 110 due to discharge by controlling the electrical connection between the first battery 110, the second battery 120, and the load 220 according to the voltage of the first battery 110. As a result, the lifespan of the first battery 110 can be increased.

[0104] Figures 12 and 13 schematically illustrate another embodiment of the discharge of a battery pack according to one embodiment of the present invention. Specifically, Figure 12 schematically illustrates the discharge process of the battery pack 100. Figure 13 schematically illustrates an exemplary configuration of the battery pack 100 during the discharge process. Here, steps S860 to S880 in Figure 12 may be performed after step S850 in Figure 9.

[0105] Step S860 may be performed after step S850 in Figure 9. Step S860 is a step in which the voltage of the second battery 120 is measured, and this may be performed by the BMS 140.

[0106] For example, in Figure 13, the BMS 140 can measure the voltage, current, and temperature of the second battery 120 via the sensing line SL.

[0107] Stage S870 is a stage in which the voltage of the first battery 110 and the voltage of the second battery 120 are compared, and this can be performed by the BMS 140. If, in stage S870, the voltage of the first battery 110 and the voltage of the second battery 120 are the same, the process proceeds to stage S880; otherwise, stage S860 may be performed.

[0108] Stage S880 is the stage of connecting the first battery 110 and the load 220, which can be performed by the BMS 140.

[0109] Specifically, the BMS140 may be configured to further connect the first battery 110 to the load 220 if the voltages of the first battery 110 and the second battery 120 are the same. That is, if both the voltages of the first battery 110 and the second battery 120 correspond to critical voltages, both the first battery 110 and the second battery 120 may be connected to the load 220.

[0110] For example, in the embodiment shown in Figure 13, the BMS 140 can connect the first battery 110 and the load 220 by controlling the operating state of the first relay 150 to the turn-on state. That is, since both the operating state of the first relay 150 and the second relay 160 are in the turn-on state, the first battery 110 and the second battery 120 can be connected to the load 220 in a parallel configuration.

[0111] If the voltages of the first battery 110 and the second battery 120 are different, and the BMS 140 controls the operating states of the first relay 150 and the second relay 160 to the full turn state, then accidents such as overheating, fire, or explosion may occur due to the difference in rated capacity between the first battery 110 and the second battery 120. Therefore, to prevent deterioration of the first battery 110, the BMS 140 first disconnects the connection between the first battery 110 and the load 220, and then, once the voltage of the second battery 120 becomes the same as the voltage of the first battery 110, it can reconnect the first battery 110 and the load 220. Since both the first battery 110 and the second battery 120 are connected to the load 220, power can be supplied to the load 220 smoothly.

[0112] Figure 14 is a schematic diagram illustrating an automobile according to another embodiment of the present invention.

[0113] Referring to Figure 14, the battery pack 100 according to an embodiment of the present invention may be included in an automobile 10 such as an electric vehicle (EV) or a hybrid vehicle (HV). The battery pack 100 can drive the automobile 10 by supplying power to the motor via an inverter provided in the automobile 10.

[0114] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations are possible within the equivalent scope of the technical concept of the present invention and the following claims by persons with ordinary skill in the art to which the present invention pertains.

[0115] Furthermore, since the present invention described above can be substituted, modified, and altered in various ways by a person with ordinary skill in the art to which the present invention belongs, without deviating from the technical concept of the present invention, it is not limited by the above-described embodiments and attached drawings, and can be constructed by selectively combining all or part of each embodiment to allow for various modifications. [Explanation of Symbols]

[0116] 10. Automobiles 100 Battery Packs 110 First Battery 120 Second Battery 130 Connector section 140 BMS 150 1st Relay 160 2nd Relay 200 External device 210 charger 220 load

Claims

1. The first battery and the second battery, A connector section including electrode terminals and communication terminals, configured to be connectable to an external device, A BMS is configured to determine whether or not the connector portion is connected to the external device, and to control the electrical connection relationship between the first battery and the second battery and the external device according to the external device connected to the connector portion, A battery pack comprising, The BMS is configured such that when a charger is connected to the connector as an external device, it connects at least one of the first battery and the second battery to the charger according to the charging type. The battery pack is characterized in that the BMS is configured to connect the second battery to the charger and disconnect the connection between the first battery and the charger when the charging type is rapid charging.

2. The battery pack according to claim 1, characterized in that the BMS is configured to receive information related to the charging type from the charger.

3. The aforementioned BMS is The battery pack according to claim 1, characterized in that, when the charging type is slow charging, the first battery and the second battery are configured to be connected to the charger.

4. The aforementioned BMS is The battery pack according to claim 1, characterized in that after the rapid charging of the second battery is completed, the charging type is changed to slow charging and the first battery and the charger are connected.

5. The first battery and the second battery, A connector section including electrode terminals and communication terminals, configured to be connectable to an external device, A BMS is configured to determine whether or not the connector portion is connected to the external device, and to control the electrical connection relationship between the first battery and the second battery and the external device according to the external device connected to the connector portion, A battery pack comprising, The BMS is configured to connect the first battery to the load and disconnect the second battery to the load when a load is connected to the connector portion, in a battery pack.

6. The aforementioned BMS is The battery pack according to claim 5, characterized in that it is configured to measure the voltage of the first battery connected to the load and to control the connection between the first battery and the second battery and the load based on the voltage of the first battery.

7. The aforementioned BMS is The battery pack according to claim 6, characterized in that it is configured to connect the second battery to the load and disconnect the connection between the first battery and the load when the voltage of the first battery is below a preset critical voltage.

8. The aforementioned BMS is The battery pack according to claim 7, characterized in that the voltage of the second battery is measured, and if the voltages of the first battery and the second battery are the same, the first battery is further connected to the load.

9. A first relay is connected between the first battery and the electrode terminal and configured to electrically connect or disconnect the first battery and the electrode terminal according to the controlled operating state, A second relay is connected between the second battery and the electrode terminal and configured to electrically connect or disconnect the second battery and the electrode terminal according to the controlled operating state, The battery pack according to claim 1 or 5, further comprising:

10. The aforementioned BMS is The battery pack according to claim 9, characterized in that it is configured to control the connection relationship between the first battery and the second battery and the external device by controlling the operating states of the first relay and the second relay.

11. The first battery and the second battery are The battery pack according to claim 1 or 5, characterized in that it is configured to have different negative electrode active materials.

12. An automobile comprising a battery pack according to any one of claims 1 to 8.

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