Battery diagnostic apparatus and method of operating same

Abstract

A battery cell diagnostic apparatus according to an embodiment disclosed herein may include a data acquisition unit for acquiring charge / discharge data while charging / discharging a battery cell, the charging / discharging data comprises a charging / discharging curve obtained when the battery unit is charged / discharged according to different charging / discharging rates; a curve acquisition unit for acquiring a first current-voltage curve based on the charge / discharge curve; a curve calculation unit for calculating, based on the first current-voltage curve, a second current-voltage curve from a specified charge / discharge rate different from the different charge / discharge rate; and a data calculation unit for calculating capacity-voltage relationship data based on the second current-voltage curve.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0015193 filed in the Korean Intellectual Property Office on February 3, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0004] Embodiments disclosed herein relate to a battery diagnostic device and a method for operating the same. Background Art

[0005] Recently, the research and development of secondary batteries has been actively carried out. In this article, the secondary battery as a rechargeable / dischargeable battery can include all traditional nickel (Ni) / cadmium (Cd) batteries, Ni / metal hydride (MH) batteries, etc. and the latest lithium ion batteries. Among secondary batteries, lithium ion batteries have a much higher energy density than traditional Ni / Cd batteries, Ni / MH batteries, etc. In addition, lithium ion batteries can be made small and lightweight, so that lithium ion batteries have been used as power sources for mobile devices. In addition, lithium ion batteries have attracted attention as the next generation of energy storage media due to the expansion of their scope of use to the power source of electric vehicles.

[0006] In addition, the secondary battery can be used as a battery pack including a battery module in which a plurality of battery cells are connected in series and / or in parallel with each other, or as a battery rack including a plurality of battery modules and a rack frame accommodating the modules.

[0007] Battery cells, battery modules, battery packs, or battery racks can be used in a variety of devices. For example, batteries can be used not only in mobile devices such as mobile phones, laptops, smartphones, and smart tablets, but also in electric vehicles (EVs, HEVs, PHEVs), large-capacity energy storage systems (ESSs), and other fields.

[0008] These batteries can be managed and controlled by a battery management system (BMS) based on their status and operation. The battery management system can be included in a device together with the batteries. The battery management system can also manage and control the batteries in a state separated from the device including the batteries. Summary of the Invention

[0009] Technical issues

[0010] A battery management system can measure various parameters of a battery to diagnose the battery's status. However, some parameters measured to diagnose the battery's status (e.g., charge capacity) may be affected by overpotentials generated during battery charging / discharging.

[0011] A solution is needed to obtain accurate charge / discharge curves of batteries by reducing the influence of overpotential.

[0012] Technical problems of the embodiments disclosed herein are not limited to the above-mentioned technical problems, and other unmentioned technical problems will be clearly understood by those of ordinary skill in the art from the following description.

[0013] Technical Solution

[0014] According to an embodiment disclosed herein, a battery cell diagnostic device includes: a data acquisition unit configured to acquire charge / discharge data during charging / discharging of a battery cell, wherein the charge / discharge data includes a charge / discharge curve acquired during charging / discharging of the battery cell according to different charge / discharge rates; a curve acquisition unit configured to acquire a first current-voltage curve based on the charge / discharge curve; a curve calculation unit configured to calculate a second current-voltage curve based on the first current-voltage curve according to a specified charge / discharge rate different from the different charge / discharge rate; and a data calculation unit configured to calculate capacity-voltage relationship data based on the second current-voltage curve.

[0015] According to an embodiment disclosed herein, a method for operating a battery cell diagnostic device includes the following steps: acquiring charge / discharge data during a charge / discharge process of a battery cell, wherein the charge / discharge data includes a charge / discharge curve acquired during charging / discharging of the battery cell according to different charge / discharge rates; acquiring a first current-voltage curve based on the charge / discharge curve; calculating a second current-voltage curve based on the first current-voltage curve according to a specified charge / discharge rate different from the different charge / discharge rate; and calculating capacity-voltage relationship data based on the second current-voltage curve.

[0016] Beneficial effects

[0017] The battery diagnostic apparatus and the operating method thereof according to various embodiments disclosed herein may obtain an accurate charge / discharge curve of a battery by reducing the influence of overpotential.

[0018] The battery diagnostic apparatus and the operating method thereof according to various embodiments disclosed herein can accurately measure the relationship between the charge variation and the voltage variation of a battery by acquiring an accurate charge / discharge curve.

[0019] Effects of the battery diagnostic apparatus and the operating method thereof according to the present disclosure are not limited to the above-mentioned effects, and other unmentioned effects will be clearly understood by those of ordinary skill in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a block diagram of a battery diagnostic apparatus according to an embodiment of the present disclosure.

[0021] Figure 2 is a flowchart illustrating an operating method of a battery diagnostic apparatus according to an embodiment of the present disclosure.

[0022] Figure 3 is a flowchart illustrating an operation of acquiring a current-voltage curve performed by a battery diagnostic apparatus according to an embodiment of the present disclosure.

[0023] Figure 4 is a flowchart illustrating an operation of reducing overpotential performed by a battery diagnostic apparatus according to an embodiment of the present disclosure.

[0024] With regard to the description of the drawings, the same reference numerals may be used to refer to the same or related parts. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the description is not intended to limit the present disclosure to a specific embodiment, and should be construed as including various modifications, equivalents, and / or substitutes according to the embodiments of the present disclosure.

[0026] It should be understood that the embodiments of this document and the terms used therein are not intended to limit the technical features set forth herein to specific embodiments, and include various changes, equivalents, or replacements of the corresponding embodiments. With respect to the description of the drawings, similar reference numerals may be used to refer to similar or related elements. It should be understood that the singular form of a noun corresponding to an item may include one or more things, unless the relevant context clearly indicates otherwise.

[0027] As used herein, each of the phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B or C" may include any or all possible combinations of the items listed together in the corresponding phrase. Unless otherwise specified, phrases such as "1 st ”, “2 nd ,” “first,” “second,” “A,” “B,” “(a)” or “(b)” may be used to simply distinguish corresponding components from each other and do not limit the components in other aspects (e.g., importance or order).

[0028] Herein, it should be understood that when an element (e.g., a first element) is referred to as being “connected with,” “coupled with,” or “linked with,” or “coupled to,” or “connected to” another element (e.g., a second element) with or without the term “operably” or “communicatively,” it means that the element can be connected to the other element directly (e.g., by wire or wirelessly) or indirectly (e.g., via a third element).

[0029] The methods according to various embodiments disclosed herein may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a compact disc read-only memory (CD-ROM)), or distributed online (e.g., downloaded or uploaded) via an application store, or distributed directly between two user devices. If distributed online, at least a portion of the computer program product may be temporarily generated or at least temporarily stored in a machine-readable storage medium, such as a memory of a manufacturer's server, a server of an application store, or a relay server.

[0030] According to embodiments disclosed herein, each component (e.g., module or program) in the above-mentioned components can include a single entity or multiple entities, and some of the multiple entities can be individually arranged in different components. According to various embodiments disclosed herein, one or more components in the above-mentioned components can be omitted, or one or more other components can be added. Alternatively or additionally, multiple components (e.g., module or program) can be integrated into a single component. In this case, according to various embodiments, the integrated component can still perform one or more functions of each component in the multiple components in a manner identical or similar to the manner in which they were performed by the corresponding components in the multiple components before integration. According to embodiments disclosed herein, the operation performed by a module, program or another component can be performed sequentially, in parallel, repeatedly or heuristically, or one or more operations can be performed or omitted in different orders, or one or more other operations can be added.

[0031] Figure 1 is a block diagram of a battery diagnostic apparatus 101 according to an embodiment of the present disclosure.

[0032] Reference Figure 1 , the battery diagnosis apparatus 101 may be connected to the electronic device 103 and the user terminal 105 by wire and / or wirelessly.

[0033] In an embodiment, the connection between the battery diagnostic apparatus 101 and the electronic device 103 may be a communication connection via a wired and / or wireless network. In an embodiment, the wired network may be based on a local area network (LAN) communication or power line communication. In an embodiment, the wireless network may be based on a short-range communication network (e.g., Bluetooth, Wireless Fidelity (WiFi), or Infrared Data Protocol (IrDA)) or a long-range communication network (e.g., a cellular network, a fourth generation (4G) network, or a fifth generation (5G) network).

[0034] In another embodiment, the connection between the battery diagnostic apparatus 101 and the electronic device 103 may be a connection using a device-to-device communication scheme such as a bus, general purpose input output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI).

[0035] In an embodiment, the connection between the battery diagnosis device 101 and the user terminal 105 may be a communication connection via a wired and / or wireless network.

[0036] In an embodiment, the electronic device 103 may be a mobile device (e.g., a mobile phone, a laptop computer, a smart phone, a smart pad), an electric vehicle (e.g., an electric vehicle (EV), a hybrid EV (HEV), a plug-in HEV (PHEV), a fuel cell EV (FCEV)), an energy storage system (ESS), or a battery swap system (BSS).

[0037] In an embodiment, the electronic device 103 may include one or more battery cells 111, 113, and 115. Each of the one or more battery cells 111, 113, and 115 may be a battery cell, a battery module, a battery pack, or a battery rack. In an embodiment, each of the one or more battery cells 111, 113, and 115 may serve as a power source for the electronic device 103.

[0038] In an embodiment, the user terminal 105 may be a mobile device (eg, a mobile phone, a laptop, a smart phone, a smart pad) or a personal computer (PC).

[0039] In an embodiment, the battery diagnostic device 101 may include a communication circuit 120, a sensor 130, a memory 140, and a processor 150. According to an embodiment, in addition to Figure 1 In addition to the components shown, Figure 1 The illustrated battery diagnostic apparatus 101 may also include at least one component (eg, a display, an input device, or an output device).

[0040] In an embodiment, the communication circuit 120 can establish a wired communication channel and / or a wireless communication channel between the battery diagnostic device 101 and the electronic device 103 and / or the user terminal 105, and send data to the electronic device 103 and / or the user terminal 105 and receive data from the electronic device 103 and / or the user terminal 105 through the established communication channel.

[0041] In an embodiment, the sensor 130 may acquire a value related to the state of the battery cells 111, 113, and 115 of the electronic device 103. In an embodiment, the value related to the state may indicate one or more values ​​of the voltage, current, resistance, SOC, state of health (SOH), or temperature of the battery cells 111, 113, and 115 or a combination thereof. Hereinafter, the value related to the state may be referred to as a 'state value'.

[0042] In implementations, memory 140 may include volatile and / or non-volatile memory.

[0043] In embodiments, the memory 140 may store data used by at least one component of the battery state estimation device 100 (e.g., the processor 150). For example, the data may include software (or instructions related thereto), input data, or output data. In embodiments, when the instructions are executed by the processor 150, the battery diagnostic device 101 may perform the operations defined by the instructions.

[0044] In an embodiment, the memory 140 may include one or more software (eg, an acquisition unit 141 , a curve acquisition unit 143 , a curve calculation unit 145 , a data calculation unit 147 , and an abnormality diagnosis unit 149 ).

[0045] In an embodiment, the processor 150 may include a central processing unit, an application processor, a graphics processing unit, a neural processing unit (NPU), an image signal processor, a sensor hub processor, or a communication processor.

[0046] In an embodiment, the processor 150 may execute software (e.g., the acquisition unit 141, the curve acquisition unit 143, the curve calculation unit 145, the data calculation unit 147, and the abnormality diagnosis unit 149) to control at least one other component (e.g., a hardware component or a software component) of the battery diagnostic device 101 connected to the processor 150 and perform various data processing or operations.

[0047] Below, taking battery cell 111 among battery cells 111, 113 and 115 as an example, a method for battery diagnosis device 101 to diagnose an abnormality of battery cell 111 through data acquisition unit 141, curve acquisition unit 143, curve calculation unit 145, data calculation unit 147 and abnormality diagnosis unit 149 will be described.

[0048] In an embodiment, the data acquisition unit 141 may acquire charge / discharge data during the charging / discharging of the battery cell 111. In an embodiment, the charge / discharge data may include a charge / discharge curve acquired during the charging / discharging of the battery cell 111 according to different charge / discharge rates (C-rates). Here, the charge / discharge curve may include information related to the voltage, current, temperature, and / or SOC of the battery cell 111 during the charging / discharging of the battery cell 111. In an embodiment, different charge / discharge rates may include 0.1C, 0.2C, 0.3C, or 1C. However, different charge / discharge rates may be merely examples and are not limited thereto.

[0049] In an embodiment, the data acquisition unit 141 may acquire charge / discharge data through the communication circuit 120. For example, the data acquisition unit 141 may receive charge / discharge data acquired by the electronic device 103 during charge / discharge of the battery cell 111 through the communication circuit 120.

[0050] In an embodiment, the data acquisition unit 141 may acquire charge / discharge data through the sensor 130. For example, the data acquisition unit 141 may receive sensed charge / discharge data acquired by the sensor 130 during charge / discharge of the battery cell 111 from the sensor 130.

[0051] In an embodiment, the curve acquisition unit 143 may acquire a current-voltage curve based on the charge / discharge curve. In an embodiment, the current-voltage curve may include information related to the relationship between the current change and the voltage change within a specified state of charge (SOC) range. In an embodiment, the specified SOC range may include any SOC range (i.e., 0% to 100%). In an embodiment, the specified SOC range may include a limited SOC range (i.e., 10% to 80%).

[0052] In an embodiment, the curve acquisition unit 143 may calculate a first variation for each charge / discharge curve, where the first variation indicates a voltage variation relative to a current variation within a specified SOC range. For example, if the SOC range used to calculate the first variation is 0% to 100% and the first variation is calculated every time the SOC increases by 0.1%, the curve acquisition unit 143 may calculate 1000 first variations for each charge / discharge curve.

[0053] In an embodiment, the curve acquisition unit 143 may acquire a first current-voltage curve of the charge / discharge curve based on the first variation. Here, the first current-voltage curve may include the first variation, which is information about the relationship between the current variation and the voltage variation.

[0054] In an embodiment, the first variation may be obtained for each designated SOC interval from a designated SOC section. For example, the designated SOC interval may be equal to 0.1%. However, the designated SOC interval may have various intervals and is not limited thereto. In an embodiment, the first variation may have a value dV / dI obtained by differentiating the voltage V with respect to the current I within the designated SOC section.

[0055] In an embodiment, the curve acquisition unit 143 may acquire a first current-voltage curve of the charge / discharge curve based on the second variation acquired by adjusting the first variation. Here, the first current-voltage curve may include the second variation, which is information related to the relationship between the current variation and the voltage variation.

[0056] More specifically, the curve acquisition unit 143 can obtain the second change in the first SOC of the SOC segment by adjusting the first change calculated in the first SOC based on other first changes calculated in the second SOC adjacent to the first SOC. The curve acquisition unit 143 can obtain the second change within the SOC segment by applying the process of obtaining the second change to the entire SOC segment. For example, when the first change is calculated whenever the SOC increases by 0.1%, the curve acquisition unit 143 can obtain the second change in a specific SOC (e.g., 10%) based on the first change in the specific SOC (e.g., 10%) and the first change in the adjacent SOC (e.g., 9.9% and 10.1%). Here, the adjustment may include averaging or weighted averaging. In an embodiment, the adjustment may also be referred to as smoothing. In an embodiment, it has been described that the second change is obtained based on three consecutive first changes, but this is merely an example. The number of consecutive first changes is not limited, and various window ranges (e.g., 5, 7, etc.) can be used.

[0057] In an embodiment, the curve acquisition unit 145 may calculate a second current-voltage curve based on the first current-voltage curve according to a specified charge / discharge rate that is different from the different charge / discharge rates. Here, the specified charge / discharge rate may be less than the different charge / discharge rates. For example, when the minimum charge / discharge rate among the different charge / discharge rates is 0.1C, the specified charge / discharge rate may be less than 0.1C. For example, the specified charge / discharge rate may be close to 0C, for example, 0.01C, 0.001C, or a charge / discharge rate less than 0.001C.

[0058] In an embodiment, the curve calculation unit 145 may identify an overpotential within a specified SOC range based on the first current-voltage curve. In an embodiment, the curve calculation unit 145 may identify the voltage change relative to the current change due to the overpotential based on the first current-voltage curve. More specifically, the curve calculation unit 145 may identify the value dV / dI obtained by differentiating the voltage V with the overpotential added relative to the current I based on the first current-voltage curve.

[0059] In an embodiment, the curve calculation unit 145 may identify a change in voltage relative to a change in current based on the first current-voltage curve at different charge / discharge rates within a specified SOC range. Subsequently, the curve calculation unit 145 may identify an overpotential based on the change within the specified SOC range by using a specified relationship between the charge / discharge rate and the change. The specified relationship may include a first-order equation, a second-order equation, a third-order equation, and an n-order equation (where n is an integer of 4 or greater) that utilizes the characteristic that the overpotential increases with increasing charge / discharge rate.

[0060] In an embodiment, the curve calculation unit 145 may obtain the second current-voltage curve by excluding the identified overpotential from the first current-voltage curve. For example, the curve calculation unit 145 may obtain the second current-voltage curve by excluding the identified overpotential from at least one first current-voltage curve among the first current-voltage curves. Here, the at least one first current-voltage curve may be a curve previously selected from the first current-voltage curves. For example, the at least one first current-voltage curve may be a first current-voltage curve based on a charge / discharge curve obtained at a minimum charge / discharge rate.

[0061] In an embodiment, the curve calculation unit 145 may obtain the second current-voltage curve by removing the voltage change relative to the current change caused by the overpotential from the at least one first current-voltage curve. In an embodiment, the curve calculation unit 145 may obtain the second current-voltage curve by removing the value dV / dI obtained by differentiating the voltage V increased due to the overpotential relative to the current I from the at least one first current-voltage curve.

[0062] In an embodiment, the data calculation unit 147 may calculate capacity-voltage relationship data based on the second current-voltage curve. Here, the capacity-voltage relationship data may indicate the relationship between the capacity change and the voltage change of the battery cell at a specified charge / discharge rate. For example, the relationship between the capacity change and the voltage change may include a value dV / dQ obtained by differentiating the voltage V with respect to the charge Q and / or a value dQ / dV obtained by differentiating the charge Q with respect to the voltage V.

[0063] In an embodiment, the abnormality diagnosis unit 149 may diagnose whether the battery cell 111 is abnormal based on the capacity-voltage relationship data.

[0064] The battery diagnostic apparatus 101 can obtain an accurate charge / discharge curve of the battery cell 111 with the influence of overpotential reduced.

[0065] Figure 2 is a flowchart illustrating an operating method of the battery diagnostic apparatus 101 according to an embodiment of the present disclosure. Figure 1 The components of the battery diagnostic device 101 are described Figure 2 .

[0066] Reference Figure 2 In operation 210, the battery diagnostic device 101 may acquire charge / discharge data during the charge / discharge of the battery cell 111. In an embodiment, the battery diagnostic device 101 may acquire the charge / discharge data by using the communication circuit 120 and / or the sensor 130. In an embodiment, the charge / discharge data may include a charge / discharge curve acquired during the charge / discharge of the battery cell 111 according to different charge / discharge rates. Here, the charge / discharge curve may include information related to the voltage, current, temperature, and / or SOC of the battery cell 111 during the charge / discharge of the battery cell 111.

[0067] In operation 220, the battery diagnostic device 101 may obtain a first current-voltage curve based on the charge / discharge curve. In embodiments, the first current-voltage curve may include information regarding the relationship between the amount of current change and the amount of voltage change within a specified SOC range. In embodiments, the specified SOC range may include any SOC range (i.e., 0% to 100%). In embodiments, the specified SOC range may include a limited SOC range (i.e., 10% to 80%).

[0068] In operation 230, the battery diagnostic device 101 may calculate a second current-voltage curve based on the first current-voltage curve according to a specified charge / discharge rate that is different from the different charge / discharge rates. Here, the specified charge / discharge rate may be less than the different charge / discharge rates. For example, when the minimum charge / discharge rate among the different charge / discharge rates is 0.1C, the specified charge / discharge rate may be less than 0.1C. For example, the specified charge / discharge rate may be close to 0C, such as 0.01C, 0.001C, or a charge / discharge rate less than 0.001C.

[0069] In operation 240, the battery diagnostic device 101 may calculate capacity-voltage relationship data based on the second current-voltage curve. The capacity-voltage relationship data may represent the relationship between the capacity change and voltage change of the battery cell at a specified charge / discharge rate. For example, the relationship between the capacity change and voltage change may include a value dV / dQ obtained by differentiating the voltage V with respect to the charge Q and / or a value dQ / dV obtained by differentiating the charge Q with respect to the voltage V.

[0070] Figure 3 is a flowchart illustrating an operation of acquiring a current-voltage curve performed by the battery diagnostic apparatus 101 according to an embodiment of the present disclosure. Figure 3 The operations can be included in Figure 2 In operation 220, reference will be made to Figure 1 The components of the battery diagnostic device 101 are described Figure 3 .

[0071] Reference Figure 3 In operation 310, the battery diagnostic device 101 may calculate a first variation within a specified SOC range. For example, if the SOC range for calculating the first variation is 0% to 100% and the first variation is calculated each time the SOC increases by 0.1%, the battery diagnostic device 101 may calculate 1000 the first variation for each charge / discharge curve. Here, the first variation may indicate a voltage variation relative to a current variation within the specified SOC range for each charge / discharge curve.

[0072] In operation 320, the battery diagnostic apparatus 101 may obtain a first current-voltage curve based on the first variation. The first current-voltage curve may include the first variation, which is information regarding the relationship between the current variation and the voltage variation. In an embodiment, the first variation may have a value dV / dI obtained by differentiating the voltage V with respect to the current I within a specified SOC range.

[0073] In an embodiment, the battery diagnostic apparatus 101 may obtain a first current-voltage curve of a charge / discharge curve based on a second variation obtained by adjusting the first variation. Here, the first current-voltage curve may include the second variation, which is information related to the relationship between the current variation and the voltage variation.

[0074] In an embodiment, the battery diagnostic device 101 may adjust the first change calculated in the first SOC based on other first changes calculated in the second SOC adjacent to the first SOC to obtain the second change in the first SOC in the SOC segment. Adjustment may include averaging or weighted averaging. In an embodiment, adjustment may also be referred to as smoothing.

[0075] Figure 4 is a flowchart illustrating an operation of reducing overpotential performed by the battery diagnostic apparatus 101 according to an embodiment of the present disclosure. Figure 4 The operations can be included in Figure 2 In operation 230, reference will be made to Figure 1 The components of the battery diagnostic device 101 are described Figure 4 .

[0076] Reference Figure 4 In operation 410, the battery diagnostic device 101 may identify an overpotential within a specified SOC range. In an embodiment, the battery diagnostic device 101 may identify the voltage change relative to the current change due to the overpotential based on a first current-voltage curve. More specifically, the battery diagnostic device 101 may identify the value dV / dI obtained by differentiating the voltage V with the overpotential added relative to the current I based on the first current-voltage curve.

[0077] In an embodiment, the battery diagnostic device 101 may identify a change in voltage relative to a change in current based on a first current-voltage curve at different charge / discharge rates within a specified SOC range. The battery diagnostic device 101 may then identify an overpotential based on the change within the specified SOC range by using a specified relationship between the charge / discharge rate and the change. The specified relationship may include a first-order equation, a second-order equation, a third-order equation, and an nth-order equation (where n is an integer of 4 or greater) that utilizes the characteristic that the overpotential increases with increasing charge / discharge rate.

[0078] In operation 420, the battery diagnostic device 101 may obtain a second current-voltage curve by excluding the overpotential from the first current-voltage curve. For example, the battery diagnostic device 101 may obtain the second current-voltage curve by excluding the identified overpotential from at least one first current-voltage curve among the first current-voltage curves. Here, the at least one first current-voltage curve may be a curve previously selected from the first current-voltage curves. For example, the at least one first current-voltage curve may be a first current-voltage curve based on a charge / discharge curve obtained at a minimum charge / discharge rate.

[0079] In an embodiment, the battery diagnostic apparatus 101 may obtain a second current-voltage curve by removing a voltage change relative to a current change due to an overpotential from at least one first current-voltage curve. In an embodiment, the battery diagnostic apparatus 101 may obtain the second current-voltage curve by removing a value dV / dI obtained by differentiating a voltage V increased due to an overpotential relative to a current I from at least one first current-voltage curve.

Claims

1. A battery cell diagnostic device, comprising: a data acquisition unit configured to acquire charge / discharge data during the charge / discharge period of the battery cell, wherein the charge / discharge data includes a charge / discharge curve acquired during the charge / discharge period of the battery cell according to different charge / discharge rates; a curve acquiring unit, configured to acquire a first current-voltage curve based on the charge / discharge curve; a curve calculation unit configured to calculate a second current-voltage curve according to a specified charge / discharge rate different from the different charge / discharge rate based on the first current-voltage curve; and A data calculation unit is configured to calculate capacity-voltage relationship data based on the second current-voltage curve.

2. The battery cell diagnostic device according to claim 1, wherein: The curve acquisition unit is further configured to: calculating a first variation amount for each of the charge / discharge curves, the first variation amount indicating a voltage variation amount relative to a current variation amount within a specified state of charge (SOC) section; and The first current-voltage curve of the charge / discharge curve is acquired based on the first change amount.

3. The battery cell diagnostic device according to claim 2, wherein: The curve acquisition unit is further configured to: obtaining a second variation in the SOC section by adjusting the first variation calculated in the first SOC based on other first variation calculated in a second SOC adjacent to the first SOC of the SOC section; and The first current-voltage curve of the charge / discharge curve is acquired based on the second change amount.

4. The battery cell diagnostic device according to claim 1, wherein: The curve calculation unit is further configured to: identifying an overpotential in a specified SOC region based on the first current-voltage curve; as well as The second current-voltage curve is obtained by excluding the identified overpotential from at least one first current-voltage curve among the first current-voltage curves.

5. The battery cell diagnostic device according to claim 4, wherein: The curve calculation unit is further configured to: identifying, based on the first current-voltage curve, an amount of change indicating an amount of voltage change relative to an amount of current change according to the different charge / discharge rates in the specified SOC section; and The overpotential is identified according to the amount of change within the specified SOC section by using a specified relationship between a charge / discharge rate and an amount of change.

6. The battery cell diagnostic device according to claim 1, wherein: The capacity-voltage relationship data indicates a relationship between a capacity change amount and a voltage change amount of the battery cell at a specified charge / discharge rate.

7. The battery cell diagnostic device according to claim 1, wherein: The designated charge / discharge rate is less than the different charge / discharge rate.

8. A method for operating a battery cell diagnostic device, the method comprising the following steps: acquiring charge / discharge data during charging / discharging of the battery cell, wherein the charge / discharge data includes charge / discharge curves acquired during charging / discharging of the battery cell according to different charge / discharge rates; acquiring a first current-voltage curve based on the charge / discharge curve; calculating, based on the first current-voltage curve, a second current-voltage curve according to a specified charge / discharge rate different from the different charge / discharge rate; and Capacity-voltage relationship data is calculated based on the second current-voltage curve.

9. The operating method according to claim 8, wherein: The step of obtaining the first current-voltage curve includes: calculating a first variation amount for each of the charge / discharge curves, the first variation amount indicating a voltage variation amount relative to a current variation amount within a specified state of charge (SOC) section; and The first current-voltage curve of the charge / discharge curve is acquired based on the first change amount.

10. The operating method according to claim 9, wherein: The step of obtaining the first current-voltage curve includes: obtaining a second variation within the SOC section by adjusting the first variation calculated in the first SOC based on other first variation calculated in a second SOC adjacent to the first SOC of the SOC section; and The first current-voltage curve of the charge / discharge curve is acquired based on the second change amount.

11. The operating method according to claim 8, wherein: The step of obtaining the second current-voltage curve includes: identifying an overpotential in a designated SOC region based on the first current-voltage curve; and The second current-voltage curve is obtained by excluding the identified overpotential from at least one first current-voltage curve among the first current-voltage curves.

12. The operating method according to claim 11, wherein: The step of obtaining the second current-voltage curve includes: identifying, based on the first current-voltage curve, an amount of change indicating an amount of voltage change relative to an amount of current change according to the different charge / discharge rates within the designated SOC section; and The overpotential is identified according to the amount of change within the specified SOC section by using a specified relationship between a charge / discharge rate and an amount of change.

13. The operating method according to claim 8, wherein: The capacity-voltage relationship data indicates a relationship between a capacity change amount and a voltage change amount of the battery cell at a specified charge / discharge rate.

14. The operating method according to claim 8, wherein: The designated charge / discharge rate is less than the different charge / discharge rate.

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