Battery protection device and method

Abstract

The battery protection device and method according to the embodiment of the present invention checks the accumulated charging period of a charging current applied to a battery cell, and compares the accumulated charging period with a preset threshold period to determine whether to permanently cut off the charging and discharging operation of the battery cell, thereby preventing the battery cell from catching fire due to the precipitation of lithium in the battery cell caused by the charging current.

Description

Technical Field

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2022-0114087, filed with the Korean Intellectual Property Office on September 8, 2022, and all of the content disclosed in the document of the Korean patent application is incorporated herein.

[0002] The present invention relates to a battery protection device and method, and more specifically, to a battery protection device and method for preventing lithium precipitation in a battery cell due to a charging current during charging and discharging of the battery cell.

Background Art

[0003] Due to the depletion of fossil fuels, the price of energy sources has increased, and the concern about environmental pollution has rapidly increased. As an environmentally friendly alternative energy source, the demand for secondary batteries is rapidly increasing.

[0004] Among secondary batteries, lithium batteries are applied to many industrial fields such as mobile application devices, automobiles, robots, and energy storage devices as a countermeasure to current environmental regulations and high crude oil prices.

[0005] Such lithium batteries are generally classified into cylindrical, prismatic, or pouch types according to the shape of the exterior material that houses the electrode assembly.

[0006] Among these, cylindrical batteries are provided in the structure of a battery pack (Cell To Pack, CTP) composed of a plurality of battery cells.

[0007] Such cylindrical batteries, due to the characteristics of the battery cells, lithium precipitation phenomena occur due to charging currents during low-temperature charging or during the generation of regeneration by motors such as in automobiles and bicycles, which can cause ignition.

[0008] Conventionally, battery protection devices were provided with conditions set to shut off charging of the battery cell when the temperature falls below 0°C, taking into account that the minimum charging temperature for a typical cylindrical battery cell is 0°C.

[0009] However, conventional battery protection devices may allow charging of the battery cells to proceed for a period of time if there is a delay before the conditions are met. If such cases accumulate, there is a risk that lithium will precipitate (Li-plate) and the battery cells will ignite.

[0010] Conventionally, when charging a battery cell, if the temperature of the battery cell drops below 0°C, there is a method to prevent the charging current from being generated from the start by controlling the battery system and charger. However, this also has the problem that it is difficult to deal with when the battery system malfunctions. [Overview of the project] [Problems that the invention aims to solve]

[0011] The objective of the present invention, which aims to solve the above-mentioned problems, is to provide a battery protection device.

[0012] Another objective of the present invention, in order to solve the problems described above, is to provide a battery protection method. [Means for solving the problem]

[0013] An embodiment of the present invention for achieving the above objective, a device for protecting at least one battery cell located inside a battery system, includes a memory and a processor that executes at least one instruction stored in the memory, wherein the at least one instruction includes an instruction to check the cumulative charging period of the charging current applied to the battery cell at or below a predetermined threshold temperature, and an instruction to compare the cumulative charging period with a predetermined threshold period and determine whether or not to permanently shut off the charging and discharging operation of the battery cell.

[0014] Here, the command used to make the above determination may include a command to permanently shut off the charging and discharging of the battery cell if the cumulative charging period is equal to or greater than the threshold period.

[0015] Furthermore, the above-mentioned command for making the determination may include a command to check the operating mode of the battery cell if the cumulative charging period is less than the threshold period, and a command to compare the charging period of the battery cell at or below the previously set threshold temperature with at least one predefined period based on the operating mode, and to control the charging and discharging of the battery cell according to the comparison result.

[0016] In this case, the command for controlling the charging and discharging of the battery cell may include a command to control the battery system in order to prevent the battery cell from being charged if the battery cell is charged for a first period of time or longer at or below the threshold temperature during the charging mode, by transmitting a first control signal to the battery system.

[0017] Furthermore, the command for controlling the charging and discharging of the battery cell may include a command to send a second control signal to the battery cell to shut off the charging switch of the battery cell in order to prevent the battery cell from being charged if the battery cell is charged for a second period of time or longer at or below the threshold temperature during charging mode.

[0018] Furthermore, the command for controlling the charging and discharging of the battery cell may include a command to transmit a third control signal to the battery system to control the output current amount of the battery cell when the battery cell is charged for a third period or longer at or below a predefined first discharge temperature during the discharge mode.

[0019] Furthermore, the command for controlling the output current amount may include a command for controlling the amount of output current required by the battery cell during discharge mode to be reduced to below a threshold value.

[0020] On the other hand, the command for controlling the charging and discharging of the battery cell may include a command that, when the battery cell is charged for a fourth period or longer at or below a predefined second discharge temperature during the discharge mode, sends a fourth control signal to the battery system to shut off an internal switch in the battery system in order to interrupt the discharge of the battery cell.

[0021] Furthermore, the command for controlling the charging and discharging of the battery cell may include a command to send a fifth control signal to the battery cell to shut off the battery cell's discharge switch if, during discharge mode, the battery cell is charged for a fifth period or longer at or below a predefined third discharge temperature.

[0022] In this case, charging of the battery cell in the above operating mode can be generated by the charger during charging mode and by the regenerative braking current during discharge mode.

[0023] On the other hand, the above-mentioned decision-making order may further include an order to update the cumulative charging period by reflecting the above-mentioned charging period in the above-mentioned cumulative charging period.

[0024] Furthermore, the aforementioned pre-set threshold period may be a pre-set period determined by adjusting the charging period of the battery cell at a constant temperature, such that lithium does not precipitate in the battery cell.

[0025] A battery protection method for protecting at least one battery cell located inside a battery system, according to one embodiment of the present invention for achieving the above objective, includes the steps of: confirming the cumulative charging period of the charging current applied to the battery cell at or below a predetermined threshold temperature; and comparing the cumulative charging period with a predetermined threshold period to determine whether or not to permanently interrupt the charging and discharging operation of the battery cell.

[0026] Here, the step of making the above determination may include a step of permanently shutting off the charging and discharging of the battery cell if the cumulative charging period is greater than or equal to the threshold period.

[0027] Further, when the cumulative charging period is less than the threshold period in the above determination step, the step may include checking the operation mode of the battery cell, and comparing the charging period of the battery cell at a temperature not higher than the preset threshold temperature according to the operation mode with at least one predefined period, and controlling the charge and discharge of the battery cell according to the comparison result.

[0028] On the other hand, the step of controlling the charge and discharge of the battery cell may include, when the battery cell is charged for a first period or longer at a temperature not higher than the threshold temperature in the charging mode, transmitting a first control signal to the battery system to control the battery system to prevent the battery cell from being charged.

[0029] Further, the step of controlling the charge and discharge of the battery cell may include, when the battery cell is charged for a second period or longer at a temperature not higher than the threshold temperature in the charging mode, transmitting a second control signal to the battery cell to cut off the charging switch of the battery cell to prevent the battery cell from being charged.

[0030] Further, the step of controlling the charge and discharge of the battery cell may include, when the battery cell is charged for a third period or longer at a temperature not higher than a predefined first discharge temperature in the discharge mode, transmitting a third control signal to the battery system to control the output current of the battery cell.

[0031] At this time, the step of controlling the output current may include controlling to reduce the output current required for the battery cell in the discharge mode to a value not higher than a threshold value.

[0032] Further, the step of controlling the charge and discharge of the battery cell may include, when the battery cell is charged for a fourth period or longer at a temperature not higher than a predefined second discharge temperature in the discharge mode, transmitting a fourth control signal to the battery system to cut off an internal switch of the battery system to cut off the discharge of the battery cell.

[0033] Furthermore, the step of controlling the charging and discharging of the battery cell may include, in the discharge mode, sending a fifth control signal to the battery cell to shut off the discharge switch of the battery cell if the battery cell is charged for a fifth period or longer at or below a predefined third discharge temperature.

[0034] Furthermore, charging of the battery cell in the above operating modes can be generated by the charger during charging mode and by the regenerative braking current during discharge mode.

[0035] On the other hand, the above determination step may further include a step of updating the cumulative charging period by reflecting the above charging period in the above cumulative charging period.

[0036] Furthermore, the aforementioned pre-set threshold period may be a pre-set period determined by adjusting the charging period of the battery cell at a constant temperature, such that lithium does not precipitate in the battery cell. [Effects of the Invention]

[0037] The battery protection device and method according to the above-described embodiment of the present invention can prevent lithium from precipitation in the battery cell due to the charging current, thereby preventing the battery cell from igniting. [Brief explanation of the drawing]

[0038] [Figure 1] This is a block diagram of a battery system to which embodiments of the present invention can be applied. [Figure 2] This is a block diagram of a battery protection device according to an embodiment of the present invention. [Figure 3] This is a flowchart illustrating a battery protection method operated by a processor in a battery protection device according to an embodiment of the present invention. [Figure 4] This flowchart illustrates a method for determining whether or not to permanently shut off a battery cell, as part of an embodiment of the present invention's battery protection method. [Figure 5]This is a flowchart illustrating a method for controlling the charging and discharging operation of a battery cell in a battery protection method according to an embodiment of the present invention. [Figure 6] This is a flowchart illustrating the operation of a battery protection method according to an embodiment of the present invention, specifically the operation of a control signal in charging mode. [Figure 7] This is a flowchart illustrating the operation of a battery protection method according to an embodiment of the present invention, specifically the operation of a control signal in discharge mode. [Modes for carrying out the invention]

[0039] The present invention can be modified in various ways and has many embodiments; therefore, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this should be understood not as limiting the present invention to specific embodiments, but rather as including all modifications, equivalents, or substitutes that fall within the spirit and technical scope of the present invention. Similar reference numerals are used for similar components in the description of each drawing.

[0040] Terms such as First, Second, A, B, etc., may be used to describe various components, but the components should not be limited by such terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the First component may be named the Second component, and similarly, the Second component may be named the First component. The term "and / or" includes a combination of multiple related items or one of multiple related items.

[0041] When it is stated that one component is "linked" or "connected" to another component, it should be understood that this may mean that it is directly linked or connected to that other component, but that there may also be another component in between. Conversely, when it is stated that one component is "directly linked" or "directly connected" to another component, it should be understood that there is no other component in between.

[0042] The terms used in this application are used solely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless they are clearly different in context. In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, steps, actions, components, parts, or combinations thereof as described in the specification, and should not be understood to preemptively exclude the presence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0043] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless explicitly defined herein.

[0044] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] Figure 1 is a block diagram of a battery system to which embodiments of the present invention can be applied.

[0046] Referring to Figure 1, a battery pack or battery module can consist of multiple battery cells connected in series. The battery cells or module can be connected to a load via positive and negative terminals to perform charging and discharging operations. The most commonly used battery cell is the lithium-ion (Li-Ion) battery cell.

[0047] Such battery cells or battery modules can be integrated with a Battery Management System (BMS).

[0048] A battery management system (BMS) monitors the current, voltage, and temperature of each battery cell or module under its control, and can control charging and discharging by calculating the State of Charge (SOC) based on the monitoring results. Here, SOC (State of Charge) is expressed as a percentage [%] of the battery's current charge level, and SOH (State of Health) is expressed as a percentage [%] of the battery's current degradation level.

[0049] In this way, a battery management system (BMS) can monitor battery cells, read cell voltages, and transmit them to other systems connected to the battery.

[0050] Furthermore, a battery management system (BMS) can transmit status data from at least one electrical component of the battery system to other systems by monitoring it. For this purpose, a BMS may include a communication module for communicating with other systems within the device included in the battery system.

[0051] The communication module of the Battery Management System (BMS) can communicate with other systems within the device using CAN (Controller Area Network). In this case, the electrical components, modules, or systems within the Battery Management System (BMS) are connected to each other via the CAN bus. This allows the Battery Management System (BMS) to remotely transmit status data acquired through monitoring of the battery pack or module and at least one electrical component constituting the Battery Management System (BMS) to other systems using CAN communication.

[0052] On the other hand, a battery management system (BMS) evenly balances the charge of battery cells to extend the lifespan of the battery system.

[0053] To perform such operations, a battery management system (BMS) can include a variety of components such as fuses, current sensing elements, thermistors, switches, and balancers, but in most cases it further includes an MCU (Microcontroller Unit) or BMIC (Battery Monitoring Integrated Chip) to control these components in conjunction. Here, the BMIC may be an IC-type component located inside the battery management system (BMS) that measures information such as the voltage, temperature, and current of the battery cells / modules. According to the embodiment, a battery management system (BMS) can be applied to an automobile.

[0054] On the other hand, generally, a battery management system (BMS) works in conjunction with a battery protection device to shut off the charge / discharge circuit when a battery malfunction occurs. In other words, a typical battery protection circuit will shut off the charge / discharge circuit and limit battery use if a malfunction occurs in any one battery cell or module.

[0055] Figure 2 is a block diagram of a battery protection device according to an embodiment of the present invention.

[0056] Referring to Figure 2, the battery protection device according to an embodiment of the present invention can control the charging and discharging operation of a battery cell by comparing the charging period at a certain temperature with a predetermined condition value when at least one battery cell in the battery system is operating below a predetermined threshold temperature.

[0057] Furthermore, the battery protection device can calculate the cumulative charging period during which the battery cell is charged at or below a pre-set threshold temperature, and permanently control the operation of the battery cell.

[0058] More specifically, the battery protection device may include a memory 100, a processor 200, a transceiver 300, an input interface device 400, an output interface device 500, and a storage device 600.

[0059] According to the embodiment, the respective components 100, 200, 300, 400, 500, and 600 included in the control unit 4000 are connected by a bus 700 and can communicate with each other.

[0060] Of the above configurations 100, 200, 300, 400, 500, and 600, the memory 100 and the storage device 600 can be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 100 and the storage device 600 can be composed of at least one of a read-only memory (ROM) and a random access memory (RAM).

[0061] Among these, memory 100 may contain at least one instruction executed by processor 200.

[0062] According to the embodiment, at least one of the above commands includes a command to check the cumulative charging period of the charging current applied to the battery cell at or below a previously set threshold temperature, and a command to compare the cumulative charging period with a previously set threshold period and determine whether or not to permanently shut off the charging and discharging operation of the battery cell.

[0063] Here, the command used to make the above determination may include a command to permanently shut off the charging and discharging of the battery cell if the cumulative charging period is equal to or greater than the threshold period.

[0064] Furthermore, the above-mentioned command for making the determination may include a command to check the operating mode of the battery cell if the cumulative charging period is less than the threshold period, and a command to compare the charging period of the battery cell at or below the previously set threshold temperature with at least one predefined period based on the operating mode, and to control the charging and discharging of the battery cell according to the comparison result.

[0065] In this case, the command for controlling the charging and discharging of the battery cell may include a command to control the battery system in order to prevent the battery cell from being charged if the battery cell is charged for a first period of time or longer at or below the threshold temperature during the charging mode, by transmitting a first control signal to the battery system.

[0066] Furthermore, the command for controlling the charging and discharging of the battery cell may include a command to send a second control signal to the battery cell to shut off the charging switch of the battery cell in order to prevent the battery cell from being charged if the battery cell is charged for a second period of time or longer at or below the threshold temperature during charging mode.

[0067] Furthermore, the command for controlling the charging and discharging of the battery cell may include a command to transmit a third control signal to the battery system to control the output current amount of the battery cell when the battery cell is charged for a third period or longer at or below a predefined first discharge temperature during the discharge mode.

[0068] In this case, the command that controls the output current amount may include a command that controls the amount of output current required by the battery cell during discharge mode to be reduced to below a threshold.

[0069] On the other hand, the command for controlling the charging and discharging of the battery cell may include a command that, when the battery cell is charged for a fourth period or longer at or below a predefined second discharge temperature during the discharge mode, sends a fourth control signal to the battery system to shut off an internal switch in the battery system in order to interrupt the discharge of the battery cell.

[0070] Furthermore, the command for controlling the charging and discharging of the battery cell may include a command to send a fifth control signal to the battery cell to shut off the battery cell's discharge switch if, during discharge mode, the battery cell is charged for a fifth period or longer at or below a predefined third discharge temperature.

[0071] In this case, charging of the battery cell in the above operating mode can be generated by the charger during charging mode and by the regenerative braking current during discharge mode.

[0072] On the other hand, the above-mentioned decision-making order may further include an order to update the cumulative charging period by reflecting the above-mentioned charging period in the above-mentioned cumulative charging period.

[0073] Furthermore, the aforementioned pre-set threshold period may be a pre-set period determined by adjusting the charging period of the battery cell at a constant temperature, such that lithium does not precipitate in the battery cell.

[0074] On the other hand, processor 200 can mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the embodiment of the present invention is performed.

[0075] As described above, the processor 200 can execute at least one program command stored in memory 100.

[0076] Figure 3 is a flowchart illustrating a battery protection method operated by a processor in a battery protection device according to an embodiment of the present invention.

[0077] Referring to Figure 3, the battery protection device according to an embodiment of the present invention can confirm the cumulative charging period during which a charging current is applied to at least one battery cell by the operation of the processor 200 (S1000).

[0078] More specifically, the battery protection device can determine the cumulative charging period of the charging current applied to the battery cell at or below a predetermined threshold temperature. In other words, the battery protection device can determine the cumulative charging period, which is the cumulative period during which the battery cell is charged at or below a predetermined threshold temperature. Here, the predetermined threshold temperature may be 0°C or below.

[0079] Subsequently, the battery protection device can determine whether or not to permanently shut off the battery cell based on the cumulative charging period (S5000).

[0080] Figure 4 is a flowchart illustrating a method for determining whether or not to permanently shut off a battery cell, as part of an embodiment of the present invention for protecting a battery.

[0081] Referring to Figure 4, the battery protection device can then compare the cumulative charging period with a predefined threshold period (S1100).

[0082] Here, the pre-set threshold period is information determined by experimental data obtained in advance, as described below, and can be pre-set as a charging period during which lithium does not precipitate in the battery cell by adjusting the charging period of the charging current applied to the battery at a constant temperature.

[0083] Preliminary experiments for setting threshold periods A battery cell with an initial voltage of 4.1V and a temperature of -20°C or lower was prepared. Subsequently, the charge-discharge cycles of the above battery cell were applied at different rates of 10, 30, 50, 100, and 500 cycles. In other words, the charging period of the charging current was set differently, and a charging current of 5A per 0.25 seconds was applied.

[0084] During this process, a 5-second pause was allowed between charging and discharging operations. Subsequently, by observing whether or not lithium precipitated from the battery cell, one of at least one charging period in which lithium did not precipitate could be selected as the threshold period.

[0085] This allows the selected threshold period to be used as comparative data with the cumulative charging period of the battery cells in the battery protection device according to the embodiment of the present invention.

[0086] Furthermore, referring to Figure 4, according to one embodiment, the battery protection device can permanently shut off the charging and discharging operation of the battery cell if the cumulative charging period is greater than or equal to the predetermined threshold period (S5100).

[0087] According to another embodiment, the battery protection device can control the charging and discharging operation of the battery cell if the cumulative charging period is less than the previously set threshold period (S5500).

[0088] Figure 5 is a flowchart illustrating a method for controlling the charging and discharging operation of a battery cell in a battery protection method according to an embodiment of the present invention.

[0089] Referring to Figure 5, the battery protection device can check the operating mode of the battery cell if the cumulative charging period is less than the previously set threshold period (S5510).

[0090] Subsequently, the battery protection device can control the charging and discharging operation of the battery cell by comparing the charging period and the previously set conditions depending on the operating mode of the battery cell (S5530). In other words, depending on the operating mode of the battery cell, if the charging period satisfies the previously set conditions, the battery protection device transmits a control signal corresponding to the conditions to the operating unit, thereby allowing the charging and discharging operation of the battery cell to be controlled by the operating unit. Here, the charging period may be the charging period of the charging current applied to the battery cell. In other words, it may be the charging period during which the battery cell is charged. For example, the previously set conditions may be a charging period during which the battery is continuously charged at a previously set threshold temperature.

[0091] Subsequently, the battery protection device can update the cumulative charging period by reflecting the charging period in the cumulative charging period (S5570).

[0092] Figure 6 is a flowchart illustrating the operation of a battery protection method according to an embodiment of the present invention, specifically the operation of a control signal in charging mode.

[0093] Referring to Figure 6, the battery protection device can confirm whether the charging period satisfies the first charging condition in the charging mode (S5531).

[0094] More specifically, when the battery protection device is operating in charging mode, if the charging of the battery cell continues for a first period or longer at a temperature below a predetermined threshold, the battery protection device can output a first control signal (S5533) and transmit it to the battery system. For example, the predetermined threshold temperature may be 0°C, and the first period may be 1 second.

[0095] When the above-described battery system receives the first control signal, it can be controlled to prevent the inflow of charging current applied to the battery cell. In other words, the battery system can interrupt the charging of the battery cell.

[0096] Subsequently, if the temperature of the battery cell remains above a pre-set threshold temperature for a second period or longer, and the cumulative charging period is less than the pre-set threshold period, the battery protection device may transmit a first release signal to the battery system. In other words, the battery protection device can release the interruption of charging of the battery cells in the battery system.

[0097] This allows the battery system to control the flow of the charging current into the battery cell, thereby enabling the battery cell to be recharged. For example, the previously set threshold temperature may be 0°C, the second period may be 3 seconds, and the previously set threshold period may be less than 25 seconds.

[0098] On the other hand, the battery protection device can check whether the charging period satisfies the second charging condition when in charging mode (S5535).

[0099] More specifically, when the battery protection device is operating in charging mode, if the charging of the battery cell continues for a second period or longer at a temperature below a predetermined threshold temperature, the battery protection device can output a second control signal (S5537) and transmit it to the battery cell. For example, the predetermined threshold temperature may be 0°C, the second period may be 3 seconds, and the predetermined threshold period may be less than 25 seconds.

[0100] When the above-mentioned battery cell receives the second control signal, it can shut off the charging switch to prevent the charging current from flowing into the battery cell. Here, the charging switch may be a Charge-FET (C-FET).

[0101] Subsequently, if the battery cell continues charging for a second period while the previously set threshold temperature is exceeded, and the cumulative charging period is less than the previously set threshold period, the battery protection device may send a second release signal to the battery cell. This allows the battery cell to connect the charging switch and resume charging. For example, the previously set threshold temperature may be 0°C, the second period 3 seconds, and the previously set threshold period 25 seconds.

[0102] Figure 7 is a flowchart illustrating the operation of a battery protection method according to an embodiment of the present invention, specifically the operation using a control signal in the discharge mode.

[0103] Referring to Figure 7, the above-mentioned battery protection device can be charged by regenerative current when in discharge mode. In other words, the above-mentioned battery protection device can be charged when in discharge mode.

[0104] According to the embodiment, the battery protection device can confirm whether the charging period of the regenerative current satisfies the first discharge condition in the discharge mode (S5551).

[0105] More specifically, when the battery protection device operates in discharge mode, if the battery cell remains charged for a period of 3 or longer at a temperature below the first discharge temperature, the battery protection device can output a third control signal (S5552) and transmit it to the battery system. For example, the third control signal may be an output control signal. The first discharge temperature may be -15°C, and the third period may be 1 second.

[0106] As a result, when the battery system receives a third control signal, it can reduce the amount of output current required for the battery cell and control the output of the battery cell.

[0107] Subsequently, if the temperature of the battery cell exceeds a pre-set threshold temperature and the cumulative charging period is less than the pre-set threshold period, the battery protection device may send a third release signal to the battery system. This allows the battery system to release the output control of the battery cell, allowing the battery cell to discharge to its original state.

[0108] On the other hand, in discharge mode, the battery protection device can confirm whether the charging period of the regenerative current satisfies the second discharge condition (S5553).

[0109] More specifically, when the battery protection device is operating in discharge mode, if the battery cell remains charged for a period of 4 or longer at or below the second discharge temperature, the battery protection device can output a fourth control signal (S5554) and transmit it to the battery system.

[0110] This allows the battery system to interrupt the discharge of the battery cells when a fourth control signal is received. For example, the second discharge temperature may be -20°C, and the fourth period may be 1 second.

[0111] Subsequently, if the temperature of the battery cell exceeds the second discharge temperature, the cumulative charge period is less than the previously set threshold period, and the battery cell is in an initial state, the battery protection device can send a fourth release signal to the battery system. This allows the battery system to release the discharge interruption of the battery cell. In other words, the battery cell can be re-discharged.

[0112] Furthermore, the battery protection device can confirm whether the charging period of the regenerative current satisfies the third discharge condition when in discharge mode (S5555).

[0113] More specifically, when the battery protection device operates in discharge mode, if the battery cell remains charged for a period of 5 or longer at or below the third discharge temperature, the battery protection device can output a fifth control signal (S5556) and transmit it to the battery cell. For example, the third discharge temperature may be -20°C, and the fifth period may be 3.

[0114] As a result, when the battery cell receives the fifth control signal, it can shut off the discharge switch to prevent the charging current from flowing into the battery cell. Here, the discharge switch may be a discharge-FET (D-FET).

[0115] Subsequently, the battery protection device may transmit a fifth release signal to the battery system if the temperature of the battery cell exceeds the third discharge temperature, the cumulative charge period is less than the previously set threshold period, and the battery cell is in an initial state.

[0116] This allows the battery cell to resume discharge by connecting the discharge switch.

[0117] The battery protection device and method according to embodiments of the present invention have been described above.

[0118] The battery protection device and method according to the embodiment of the present invention can prevent lithium from precipitation in the battery cell and causing the battery cell to ignite due to the charging current by checking the cumulative charging period of the charging current applied to the battery cell and comparing the cumulative charging period with a pre-set threshold period to determine whether or not to permanently interrupt the charging and discharging operation of the battery cell.

[0119] The operation of the methods according to the embodiments and experimental examples of the present invention can be embodied as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. Furthermore, computer-readable recording media can be distributed across networked computer systems, allowing computer-readable programs or code to be stored and executed in a distributed manner.

[0120] Furthermore, computer-readable recording media can include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, and flash memory. Program instructions can include not only machine code, such as that produced by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

[0121] Some aspects of the present invention have been described in the context of apparatus, but they can also be described by corresponding methods, where a block or apparatus corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method can be described by corresponding blocks or items or features of corresponding apparatus. Some or all of the method steps can be carried out by (or using) hardware devices such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps can be carried out by such devices.

[0122] While preferred embodiments of the present invention have been described above with reference to the present invention, those skilled in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and scope of the invention as set forth in the following claims. [Explanation of Symbols]

[0123] 1000: Battery protection device 100: Memory 200: Processor 300: Transceiver / Receiver 400: Input Interface Device 500: Output interface device 600: Storage device 700: Bus

Claims

1. A device for protecting at least one battery cell located inside a battery system, memory; and Includes a processor that executes at least one instruction stored in the memory, The aforementioned at least one instruction, A command to check the cumulative charging period of the charging current applied to the battery cell at or below a previously set threshold temperature, and The command includes a determination of whether or not to permanently shut off the charging and discharging of the battery cell by comparing the cumulative charging period with a previously set threshold period. The order that makes the aforementioned determination is, If the cumulative charging period is less than the threshold period, a command to check the operating mode of the battery cell, and A battery protection device that includes a command to control the charging and discharging of the battery cell according to the comparison result, by comparing the charging period of the battery cell at or below the pre-set threshold temperature with at least one pre-defined period according to the operating mode.

2. The order that makes the aforementioned determination is, The battery protection device according to claim 1, which includes an instruction to permanently shut off charging and discharging of the battery cell if the cumulative charging period is equal to or greater than the threshold period.

3. The command to control the charging and discharging of the aforementioned battery cell is: The battery protection device according to claim 1, further comprising a command to control the battery system to prevent charging of the battery cells when the battery cells are charged for a first period of time or longer at or below the threshold temperature during charging mode, by transmitting a first control signal to the battery system.

4. The command to control the charging and discharging of the aforementioned battery cell is: The battery protection device according to claim 1, further comprising a command to transmit a second control signal to the battery cell to shut off the charging switch of the battery cell in order to prevent the battery cell from being charged if the battery cell is charged for a second period of time or longer at or below the threshold temperature during charging mode.

5. The command to control the charging and discharging of the aforementioned battery cell is: The battery protection device according to claim 1, which includes a command to transmit a third control signal to the battery system to control the output current amount of the battery cell when the battery cell is charged for a third period or longer at or below a predefined first discharge temperature during discharge mode.

6. The aforementioned command to control the output current amount is: The battery protection device according to claim 5, which includes a command to control the amount of output current required for the battery cell during discharge mode to be reduced to below a threshold.

7. The command to control the charging and discharging of the aforementioned battery cell is: The battery protection device according to claim 1, further comprising, when the battery cell is charged for a fourth period or longer at or below a predefined second discharge temperature during discharge mode, a command to transmit a fourth control signal to the battery system to control an internal switch in the battery system to interrupt the discharge of the battery cell.

8. The command to control the charging and discharging of the aforementioned battery cell is: The battery protection device according to claim 1, further comprising, when the battery cell is charged for a fifth period or longer at or below a predefined third discharge temperature during discharge mode, a command to transmit a fifth control signal to the battery cell to shut off the discharge switch of the battery cell.

9. The charging of the battery cell in the aforementioned operating mode is The battery protection device according to claim 1, which is generated by the charger during charging mode and by the regenerative braking current during discharge mode.

10. The order that makes the aforementioned determination is, The battery protection device according to claim 1, further comprising an instruction to update the cumulative charging period by reflecting the charging period in the cumulative charging period.

11. The aforementioned previously set threshold period is The battery protection device according to claim 1, wherein the charging period of the battery cell at a constant temperature is adjusted to a predetermined period as a charging period during which lithium does not precipitate in the battery cell.

12. A method for protecting at least one battery cell located inside a battery system, A step of confirming the cumulative charging period of the charging current applied to the battery cell at or below a previously set threshold temperature; and The process includes a step of comparing the cumulative charging period with a previously set threshold period to determine whether or not to permanently shut off the charging and discharging of the battery cell. The aforementioned determination step is, If the cumulative charging period is less than the threshold period, the step of checking the operating mode of the battery cell; and A battery protection method comprising the steps of: comparing the charging period of the battery cell at or below the pre-set threshold temperature according to the operating mode with at least one pre-defined period, and controlling the charging and discharging of the battery cell according to the comparison result;

13. The aforementioned determination step is, The battery protection method according to claim 12, further comprising the step of permanently shutting off the charging and discharging of the battery cell if the cumulative charging period is greater than or equal to the threshold period.

14. The step of controlling the charging and discharging of the battery cell is: The battery protection method according to claim 12, further comprising the step of transmitting a first control signal to the battery system to control the battery system in order to prevent charging of the battery cell if the battery cell is charged for a first period of time or longer at or below the threshold temperature during charging mode.

15. The step of controlling the charging and discharging of the battery cell is: The battery protection method according to claim 12, further comprising the step of transmitting a second control signal to the battery cell to shut off the charging switch of the battery cell in order to prevent the battery cell from being charged if the battery cell is charged for a second period of time or longer at or below the threshold temperature during charging mode.

16. The step of controlling the charging and discharging of the battery cell is: The battery protection method according to claim 12, further comprising the step of transmitting a third control signal to the battery system to control the output current amount of the battery cell when the battery cell is charged for a third period or longer at or below a predefined first discharge temperature during discharge mode.

17. The above-mentioned step of controlling the output current amount is: The battery protection method according to claim 16, further comprising the step of controlling the amount of output current required for the battery cell during discharge mode to be reduced to below a threshold.

18. The step of controlling the charging and discharging of the battery cell is: The battery protection method according to claim 12, further comprising the step of transmitting a fourth control signal to the battery system to shut off an internal switch in the battery system in order to interrupt the discharge of the battery cell if, during discharge mode, the battery cell is charged for a fourth period or longer at or below a predefined second discharge temperature.

19. The step of controlling the charging and discharging of the battery cell is: The battery protection method according to claim 12, further comprising the step of transmitting a fifth control signal to the battery cell to shut off the discharge switch of the battery cell when the battery cell is charged for a fifth period or longer at or below a predefined third discharge temperature during discharge mode.

20. The charging of the battery cell in the aforementioned operating mode is The battery protection method according to claim 12, wherein the current is generated by the charger during charging mode and by the regenerative braking current during discharging mode.

21. The aforementioned determination step is, The battery protection method according to claim 12, further comprising the step of updating the cumulative charging period by reflecting the charging period in the cumulative charging period.

22. The aforementioned previously set threshold period is The battery protection method according to claim 12, wherein the charging period of the battery cell at a constant temperature is adjusted to a predetermined period as a charging period during which lithium does not precipitate in the battery cell.

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