Prelithiation diagnostic device and method

Abstract

A pre-lithiation diagnostic device according to one aspect of the present invention may include: a memory unit that stores a positive electrode reference start value and a negative electrode reference start value for a reference battery; and a control unit that is configured to acquire a positive electrode target profile and a negative electrode target profile for a target battery to be diagnosed, recognize the positive electrode target start value and the negative electrode target start value from the positive electrode target profile and the negative electrode target profile, and determine a lithium charge amount for a pre-lithiation process for the target battery based on at least one of the positive electrode reference start value, the negative electrode reference start value, the positive electrode target start value, and the negative electrode target start value.

Description

[Technical Field]

[0001] The present invention relates to a pre-lithiation diagnostic device and method, and more particularly to a device and method for diagnosing the condition of a battery based on the amount of lithium in the battery.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0181100, filed on December 21, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] Recently, as demand for portable electronic products such as notebook PCs, video cameras, and mobile phones has surged and development of electric vehicles, energy storage batteries, robots, and satellites has gained momentum, research into high-performance batteries that can be repeatedly charged and discharged is actively underway.

[0004] Currently, commercially available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Of these, lithium batteries are attracting attention due to their advantages over nickel-based batteries, such as almost no memory effect, freedom in charging and discharging, a very low self-discharge rate, and high energy density.

[0005] Conventional lithium batteries use lithium-intercalated compounds such as LiCoO2 and LiMn2O4 as the positive electrode, so the battery is manufactured without lithium intercalated in the electrode used as the negative electrode. When the electrode used as the negative electrode is a carbon electrode, a passivation film is formed on the surface of the carbon electrode during the first charge. This film prevents organic solvents from intercalating between the carbon lattice layers, suppressing the decomposition reaction of the organic solvent, stabilizing the carbon structure and improving the reversibility of the carbon electrode, making it possible to use it as a negative electrode for lithium batteries.

[0006] However, because this film formation reaction is irreversible, it has the adverse effect of reducing the capacity of the battery by causing the consumption of lithium ions. In addition, because the charge / discharge efficiency of carbon electrodes and positive electrodes is not 100%, the consumption of lithium ions occurs as the number of cycles increases, reducing the electrode capacity and ultimately shortening the cycle life.

[0007] To compensate for reduced electrode capacity, a pre-lithiation process is used during battery manufacturing, in which lithium is supplied to the anode in advance. When a battery containing a pre-lithiation anode is manufactured using the pre-lithiation process, it is necessary to determine whether the pre-designed amount of lithium was supplied to the anode. For example, because at least a portion of the lithium may be lost unpredictably during storage or manufacturing of a completed battery, it is necessary to verify whether the final completed battery accurately reflects the designed lithium charge capacity. However, verifying the lithium charge capacity requires disassembling the completed battery and discharging the anode to verify the lithium charge capacity, which presents a problem. Therefore, there is a need to develop a technology that can verify the lithium charge capacity of the anode without disassembling the battery. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in view of the above problems, and has as its object to provide a pre-lithiation diagnosis device and method that can non-destructively diagnose the pre-lithiation state of a battery.

[0009] Other objects and advantages of the present invention can be understood from the following description and will become more apparent from the embodiments of the present invention, and the objects and advantages of the present invention can be realized by the means and combinations thereof as claimed. [Means for solving the problem]

[0010] A pre-lithiation diagnostic device according to an embodiment of the present invention includes: a memory unit that stores a positive electrode reference start value and a negative electrode reference start value for a reference battery; and a control unit that is configured to acquire a positive electrode target profile and a negative electrode target profile for a target battery to be diagnosed, recognize the positive electrode target start value and the negative electrode target start value from the positive electrode target profile and the negative electrode target profile, and determine a lithium charge amount for a pre-lithiation process for the target battery based on at least one of the positive electrode reference start value, the negative electrode reference start value, the positive electrode target start value, and the negative electrode target start value.

[0011] The control unit may be configured to determine the lithium charge amount based on the negative electrode reference start value and the negative electrode target start value.

[0012] The control unit may be configured to calculate a difference between the negative electrode reference start value and the negative electrode target start value, and determine the lithium charge amount based on the calculated difference and a preset positive electrode load amount.

[0013] The control unit may be configured to determine the lithium charge amount based on a first difference that is a difference between the negative electrode reference start value and the positive electrode reference start value and a second difference that is a difference between the negative electrode target start value and the positive electrode target start value.

[0014] The control unit may be configured to calculate a third difference, which is the difference between the first difference and the second difference, and to determine the lithium charge amount based on the calculated third difference and a preset positive electrode load amount.

[0015] The reference battery may include a battery that has no lithium charged during the prelithiation process, or a battery that has a preset amount of lithium charged.

[0016] The positive and negative reference start values ​​may be configured to be set to the positive and negative SOCs of the reference battery, respectively, when the SOC of the reference battery corresponds to a preset reference SOC.

[0017] The target battery may further include a measurement unit configured to measure a voltage of the target battery, and the control unit may be configured to generate a full cell profile for the target battery based on the voltage measured by the measurement unit, and to obtain the positive electrode target profile and the negative electrode target profile from the full cell profile.

[0018] The memory unit may be configured to store a positive electrode reference profile and a negative electrode reference profile for the reference battery, and the control unit may be configured to adjust the positive electrode reference profile and the negative electrode reference profile to correspond to the full-cell profile to obtain the positive electrode target profile and the negative electrode target profile, respectively.

[0019] The control unit may be configured to compare the lithium charge amount with a preset reference charge amount, and diagnose the state of the target battery based on the comparison result.

[0020] A battery manufacturing apparatus according to another embodiment of the present invention may include a prelithiation diagnostic apparatus according to the present invention.

[0021] A pre-lithiation diagnosis method according to yet another embodiment of the present invention may include: a target profile acquisition step of acquiring a positive target profile and a negative target profile for a target battery to be diagnosed; a target start value recognition step of recognizing a positive target start value and a negative target start value from the positive target profile and the negative target profile; and a lithium charge amount determination step of determining a lithium charge amount for a pre-lithiation process for the target battery based on at least one of a positive reference start value, a negative reference start value, the positive target start value, and the negative target start value for a reference battery. [Effects of the Invention]

[0022] According to one embodiment of the present invention, there is provided a pre-lithiation diagnostic device capable of checking the amount of lithium charged in advance to a negative electrode.

[0023] In particular, the present invention allows the lithium charge amount to be confirmed non-destructively, without disassembling the completed battery, thereby enabling easier and faster diagnosis of the battery condition.

[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, together with the detailed description of the invention, serve to further understand the technical concept of the present invention, so the present invention should not be interpreted as being limited to the matters described in the drawings. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram of a prelithiation diagnostic device 100 according to one embodiment of the present invention. [Figure 2] The profile for the reference battery is shown. [Figure 3] The profile for the target battery is shown. [Figure 4] FIG. 10 is a diagram for explaining how a positive electrode target profile and a negative electrode target profile are generated from a full-cell profile Tf of a target battery. [Figure 5] 1 is a flow chart that schematically illustrates a prelithiation diagnostic method according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor himself can appropriately define the concepts of terms in order to best explain the invention.

[0028] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0029] Furthermore, if a detailed description of known functions or configurations related to the present invention is deemed to obscure the gist of the present invention, that description will be omitted.

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

[0031] Furthermore, throughout the specification, when a part "includes" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified. Furthermore, terms such as memory unit, control unit, and measurement unit described in the specification refer to units that process at least one function or operation, and may be embodied in hardware, software, or a combination of hardware and software.

[0032] Furthermore, throughout this specification, when a part is said to be "coupled" to another part, this includes not only "directly coupled" but also "indirectly coupled" via another element in between.

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0034] FIG. 1 is a schematic diagram of a prelithiation diagnostic device 100 according to one embodiment of the present invention.

[0035] Referring to FIG. 1, the prelithiation diagnostic device 100 may include a memory unit 110 and a control unit 120.

[0036] The memory unit 110 may store data and programs necessary for each component of the pre-lithiation diagnostic device 100 to operate and function, or data generated in the process of performing the operation and function. The memory unit 110 may be located inside or outside the control unit 120 and may be connected to the control unit 120 by various known means. The memory unit 110 may store at least one program, application, data, or instructions to be executed by the control unit 120. The type of the memory unit 110 is not particularly limited as long as it is a known information storage means capable of recording, erasing, updating, and reading data. The memory unit 110 may be embodied as at least one of a flash memory type, a hard disk type, a solid state disk (SSD) type, a silicon disk drive (SDD) type, a multimedia card micro type, a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), and a programmable read-only memory (PROM), but the present invention is not necessarily limited to such a specific form of the memory unit 110. The memory unit 110 may also store program code that defines processes that can be executed by the control unit 120.

[0037] According to one embodiment, the memory unit 110 may be configured to store a positive reference start value and a negative reference start value for a reference battery. Here, the reference battery may be a battery of the same type as the target battery to be diagnosed or a battery designed to have the same characteristics. Herein, the term "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 may be considered a battery. Also, the term "battery" may refer to a battery module in which multiple cells are connected in series and / or parallel. For convenience of explanation, the term "battery" will be used hereinafter to refer to a single independent cell.

[0038] According to one embodiment, the reference battery may refer to a battery that has not undergone a pre-lithiation process, in which lithium ions are supplied to the negative electrode in advance during manufacturing, for comparison with a target battery. According to another embodiment, the reference battery may be a battery in which the amount of lithium ions supplied through the pre-lithiation process is known with high reliability, i.e., the amount of lithium ions supplied in advance is accurately known. Hereinafter, the reference battery will be described as a battery in which the pre-lithiation process has not been applied. Furthermore, for convenience of explanation, the amount of lithium ions supplied in advance through the pre-lithiation process will be referred to as the lithium charge amount.

[0039] The positive and negative reference starting values ​​may be configured to be set to the positive and negative SOCs of the reference battery, respectively, when the SOC of the reference battery corresponds to a preset reference SOC.

[0040] Specifically, the positive and negative reference start values ​​may be set to the positive and negative characteristic values ​​of the reference battery, respectively, when the SOC of the reference battery corresponds to a predetermined reference SOC. In one embodiment, the positive reference start value may refer to the positive SOC or positive voltage value when the reference battery corresponds to a predetermined SOC, and the negative reference start value may refer to the negative SOC or negative voltage value when the reference battery corresponds to the predetermined SOC.

[0041] Even when a battery (e.g., a reference battery or a target battery) including a negative electrode and a positive electrode corresponds to a set SOC value, the negative electrode SOC and positive electrode SOC may differ from the set value. There are lower and upper voltage limits at which a battery can operate, and each electrode may have a predetermined charge amount below the lower limit voltage and above the upper limit voltage. For example, even when the SOC of a battery is 0%, which indicates a fully discharged state, the charge amount of the negative electrode may be a predetermined charge amount rather than 0%. Similarly, when the SOC of a battery is 0%, the charge amount of the positive electrode may be a predetermined charge amount rather than 0%.

[0042] The memory unit 110 may store information related to the positive electrode SOC and the negative electrode SOC of a reference battery that has not undergone a pre-lithiation process, at a predetermined SOC, for example, an SOC of 0% or an SOC of 10%. For example, at an SOC of 0%, which is a fully discharged state of the reference battery, the positive electrode SOC may be 4.5% and the negative electrode SOC may be 0.7%. In this case, the positive electrode reference starting value may be 4.5% and the negative electrode reference starting value may be 0.7%.

[0043] 2 shows a profile for a reference battery. The profile for the reference battery is stored in the memory unit 110, and the control unit 120, which will be described later, may read the positive and negative reference start values ​​from the profile. Alternatively, instead of storing the profile for the reference battery directly in the memory unit 110, the positive and negative reference start values ​​obtained from the profile for the reference battery may be stored in the memory unit 110 as reference data. In addition, the memory unit 110 may further store a mapping table (not shown) indicating a correspondence relationship between the positive electrode SOC and the positive electrode voltage and a correspondence relationship between the negative electrode SOC and the negative electrode voltage.

[0044] 2, an example of a full-cell profile Rf, a positive electrode reference profile Rp, and a negative electrode reference profile Rn for a reference battery is shown. The x-axis of the graph in FIG. 2 represents SOC (%), and the y-axis represents voltage (V). The full-cell profile Rf, the positive electrode reference profile Rp, and the negative electrode reference profile Rn for the reference battery are stored in the memory unit 110, or data sets constituting the profiles (e.g., positive electrode SOC and negative electrode SOC according to the SOC of the reference battery) may be stored in the memory unit 110.

[0045] Referring to FIG. 2, when the SOC of the reference battery is 0%, the full cell voltage is 2.5V, the positive electrode voltage is 3.5V, and the negative electrode voltage is 1V. According to the mapping table stored in the memory unit 110, when the positive electrode voltage is 3.5V, the positive electrode SOC is 4.5%, and when the negative electrode voltage is 1V, the negative electrode SOC is 0.7%. In the above example, when the SOC of the reference battery corresponds to a predetermined SOC (e.g., SOC 0%), the positive electrode reference starting value may be set to 4.5%, which is the positive electrode SOC, and the negative electrode reference starting value may be set to 0.7%, which is the negative electrode SOC. It should be noted that these values ​​are merely examples and may vary depending on the characteristics of the battery.

[0046] The control unit 120 may be operatively connected to other components of the pre-lithiation diagnostic device 100 , such as the memory unit 110 or the measurement unit 130 , and may control various operations of the pre-lithiation diagnostic device 100 .

[0047] The control unit 120 can execute one or more instructions to perform various operations of the prelithiation diagnostic device 100. The control unit 120 can optionally include a processor, an application-specific integrated circuit (ASIC), a chipset, a logic circuit, a register, a communication modem, a data processing device, etc., known in the art, to execute various control logic performed in the present invention. Furthermore, when the control logic is embodied as software, the control unit 120 can be embodied as a collection of program modules. In this case, the program modules can be stored in the memory unit 110 and executed by the control unit 120.

[0048] According to one embodiment, the control unit 120 may be configured to obtain a positive target profile and a negative target profile for a target battery to be diagnosed.

[0049] In one example, the positive and negative target profiles can be obtained by discharging the target battery directly from a three-electrode method or a coin cell formed by disassembling the target battery.

[0050] Preferably, the control unit 120 may acquire a positive electrode target profile and a negative electrode target profile for the target battery in a non-destructive manner. Specifically, the control unit 120 may acquire a full-cell profile for the target battery and acquire a positive electrode target profile and a negative electrode target profile from the acquired full-cell profile. With reference to FIG. 3 , an embodiment in which the control unit 120 recognizes a positive electrode target start value and a negative electrode target start value from the positive electrode target profile and the negative electrode target profile will be described.

[0051] Figure 3 shows the profile for the target battery.

[0052] 3, there is shown an example of a full cell profile Tf, a positive electrode target profile Tp, and a negative electrode target profile Tn for a target battery. The x-axis of the graph in FIG. 3 represents SOC (%), and the y-axis represents voltage (V).

[0053] The target battery's profiles (full cell profile Tf, positive electrode target profile Tp, and negative electrode target profile Tn) may vary depending on the state of the target battery, i.e., depending on the amount of lithium precharged into the target battery through a prelithiation process. Figure 3 can be understood as an example of such target battery profiles. The control unit 120 may acquire the full cell profile Tf for the target battery and acquire the positive electrode target profile Tp and the negative electrode target profile Tn from the acquired full cell profile Tf in a non-destructive manner without disassembling the target battery.

[0054] According to one embodiment, the control unit 120 may be configured to recognize the positive and negative target start values ​​from the positive and negative target profiles Tp and Tn.

[0055] The positive and negative target start values ​​may be set to the positive and negative characteristic values, respectively, when the SOC of the target battery corresponds to a predetermined reference SOC. Specifically, the positive target start value may refer to the positive SOC or positive voltage value when the target battery corresponds to a predetermined SOC, and the negative target start value may refer to the negative SOC or negative voltage value when the target battery corresponds to the predetermined SOC.

[0056] Here, the reference SOC for obtaining the positive electrode reference start value and the negative electrode reference start value may be the same as the reference SOC for obtaining the positive electrode target start value and the negative electrode target start value. In this way, when the control unit 120 obtains the positive electrode reference start value, the negative electrode reference start value, the positive electrode target start value, and the negative electrode target start value at the same SOC, the accuracy of the calculated lithium charge amount may be improved.

[0057] In one embodiment, the control unit 120 may acquire and recognize the positive reference start value, the negative reference start value, the positive target start value, and the negative target start value when the SOC of the reference battery is 0% and the SOC of the target battery is 0%. Alternatively, the control unit 120 may acquire and recognize the positive reference start value, the negative reference start value, the positive target start value, and the negative target start value when the SOC of the reference battery is 10% and the SOC of the target battery is 10%. In various embodiments, the SOC of the battery from which the positive reference start value, the negative reference start value, the positive target start value, and the negative target start value are acquired may be changed.

[0058] Specifically, the control unit 120 can recognize the positive electrode target start value and the negative electrode target start value based on a mapping table (not shown) stored in the memory unit 110 that indicates the correspondence between the positive electrode SOC and the positive electrode voltage and the correspondence between the negative electrode SOC and the negative electrode voltage.

[0059] Referring to FIG. 3, when the SOC of the target battery is 0%, the full cell voltage is 2.5V, the positive electrode voltage is 3V, and the negative electrode voltage is approximately 0.6V. According to the mapping table stored in the memory unit 110, when the positive electrode voltage is 3V, the positive electrode SOC is 1.1%, and when the negative electrode voltage is 0.6V, the negative electrode SOC may be 11.4%. In this case, when the SOC of the target battery corresponds to a predetermined SOC (e.g., SOC 0%), the positive electrode target start value may be set to 1.1%, which is the positive electrode SOC, and the negative electrode target start value may be set to 0.6%, which is the negative electrode SOC. Note that these values ​​are merely examples and may vary depending on the characteristics of the battery.

[0060] According to one embodiment, the control unit 120 may be configured to determine the lithium charge amount of the pre-lithiation process for the target battery based on at least one of the positive electrode reference start value, the negative electrode reference start value, the positive electrode target start value, and the negative electrode target start value.

[0061] Specifically, the control unit 120 may calculate at least two or more parameters selected from the recognized positive electrode reference start value, negative electrode reference start value, positive electrode target start value, and negative electrode target start value, and calculate the lithium charge amount for the target battery pre-charged in the pre-lithiation process.

[0062] According to this embodiment of the present invention, it is possible to calculate the lithium charge amount pre-charged in a battery to be diagnosed in a simple manner. Therefore, since the lithium charge amount can be calculated without disassembling a battery that has already been manufactured, it is possible to confirm whether the lithium has been charged in the battery as designed. Therefore, it is possible to diagnose battery abnormalities in a simple and accurate manner. Hereinafter, an embodiment of determining the lithium charge amount will be described in detail.

[0063] According to one embodiment, the control unit 120 may be configured to determine the lithium charge amount based on the negative electrode reference start value and the negative electrode target reference value.

[0064] 2 and 3, if the SOCs of the target battery and the reference battery are 0%, the negative SOC of the reference battery may be 0.7% and the negative SOC of the target battery may be 11.4%. That is, the control unit 120 may recognize the negative reference start value as 0.7% and the negative target start value as 11.4%.

[0065] The control unit 120 may calculate the difference between the negative electrode reference start value and the negative electrode target start value using the formula "|negative electrode reference start value - negative electrode target start value|." For example, if the negative electrode reference start value is 0.7% and the negative electrode target start value is 11.4%, the difference may be 10.7%. The control unit 120 may recognize that the target battery has been pre-lithiated by an amount corresponding to the difference between the negative electrode reference start value and the negative electrode target start value. In other words, the control unit 120 may determine the lithium charge amount corresponding to the difference between the negative electrode reference start value and the negative electrode target start value.

[0066] Specifically, the control unit 120 may determine the lithium charge amount based on the difference between the negative electrode reference start value and the negative electrode target start value and a preset load amount. The load amount may be either the negative electrode load amount or the positive electrode load amount. Hereinafter, an example will be described in which the lithium charge amount is determined based on the positive electrode load amount.

[0067] For example, if the difference between the negative electrode reference starting value and the negative electrode target starting value is calculated to be 10.7% as described above, the control unit 120 may determine the lithium charge capacity of the target battery by multiplying the calculated difference by the preset positive electrode load amount, i.e., the positive electrode load amount of the target battery. That is, the control unit 120 may determine the lithium charge capacity using the formula "|negative electrode reference starting value - negative electrode target starting value| × positive electrode load amount ÷ 100." In this formula, the "100" is based on the fact that the difference between the negative electrode reference starting value and the negative electrode target starting value is expressed as the SOC, which has units of %, and is omitted when the SOC is expressed as a number between 0 and 1.

[0068] The positive electrode load of the target battery is 3mAh / cm 2 is preset, the control unit 120 calculates the value of about 0.321 mAh / cm by calculating the formula 10.7 × 3 ÷ 100. 2 It can be determined that the negative electrode of the target battery has been pre-charged with lithium (lithium ions) through the prelithiation process by the magnitude of

[0069] In one embodiment, the control unit 120 may determine the lithium charge capacity based on the amount of shift in the negative electrode starting value relative to the positive electrode starting value. Battery characteristics may change for various reasons during the manufacturing process or storage of a completed battery. In this case, the negative electrode profile and positive electrode profile of the battery may shift to have the same tendency. Therefore, by calculating the amount of shift in the negative electrode profile relative to the positive electrode profile and comparing the calculated amounts of shift between the target battery and the reference battery, the lithium charge capacity may be calculated with improved accuracy.

[0070] The control unit 120 may calculate the difference between the negative electrode reference start value and the positive electrode reference start value. For example, as described with reference to FIG. 2, the positive electrode reference start value may be 4.5%, and the negative electrode reference start value may be 0.7%. The control unit 120 may calculate the difference as −3.8% using the formula “|negative electrode reference start value−positive electrode reference start value|.” The calculated value may be referred to as a first difference.

[0071] The control unit 120 may calculate the difference between the negative electrode target start value and the positive electrode target start value. For example, as described with reference to FIG. 3, the positive electrode target start value may be 1.1%, and the negative electrode target start value may be 11.4%. The control unit 120 may calculate the difference as 10.3% using the formula "|negative electrode target start value-positive electrode target start value|". The calculated value may be referred to as the second difference.

[0072] The control unit 120 may determine the lithium charge amount based on the first difference and the second difference.

[0073] The control unit 120 may calculate 14.1% using the formula "|first difference - second difference|." The control unit 120 may recognize that the target battery has undergone pre-lithiation by a magnitude corresponding to the third difference, which is the difference between the first difference and the second difference. That is, the control unit 120 may determine the lithium charge amount corresponding to the difference (third difference) between the negative electrode reference start value and the positive electrode reference start value (first difference) and the difference (second difference) between the negative electrode target start value and the positive electrode target start value. In this case, the unique characteristics of the battery, i.e., the amount of profile shift, can be reflected, allowing the pre-lithiation diagnosis device according to the present invention to more accurately determine the lithium charge amount.

[0074] Specifically, the controller 120 may determine the lithium charge amount based on a third difference, which is the difference between the first difference and the second difference, and a preset load amount. The load amount may be either a negative electrode load amount or a positive electrode load amount. Hereinafter, the determination of the lithium charge amount based on the positive electrode load amount will be described with reference to an example.

[0075] For example, if the third difference, which is the difference between the first difference and the second difference, is calculated as 14.1% as described above, the control unit 120 may determine the lithium charge amount of the target battery by multiplying the calculated third difference by the preset positive electrode load amount, i.e., the positive electrode load amount of the target battery. That is, the control unit 120 may determine the lithium charge amount using the formula "|first difference - second difference| × positive electrode load amount ÷ 100." Similarly, in the formula, the "100" is omitted because the first difference and the second difference are expressed as SOC, which has units of %, and is omitted when SOC is expressed as a number between 0 and 1.

[0076] The positive electrode load of the target battery is 3mAh / cm 2 is preset, the control unit 120 calculates the value of about 0.423 mAh / cm by calculating the formula 14.1 × 3 ÷ 100. 2 It can be determined that the negative electrode of the target battery has been pre-charged with lithium (lithium ions) through the prelithiation process by the magnitude of

[0077] Also, in one embodiment, the reference battery may include a battery that has no lithium charged or that has a preset amount of lithium charged in a prelithiation process.

[0078] If the reference battery has not been charged with lithium during the pre-lithiation process, i.e., if the reference battery has not undergone the pre-lithiation process, the control unit 120 may determine the lithium charge capacity of the target battery in the manner described above. In various embodiments, if the reference battery has undergone the pre-lithiation process, the control unit 120 may determine the lithium charge capacity of the target battery by supplementing the lithium charge capacity contained in the reference battery. For example, if the lithium charge capacity pre-charged in the reference battery is 0.1 mAh / cm 2 If this value has a reliable accuracy, the control unit 120 multiplies the lithium charge amount calculated in the above manner by 0.1 mAh / cm, which is the lithium charge amount previously charged in the reference battery. 2Therefore, according to an embodiment of the present invention, it is possible to determine the final lithium charge amount for the target battery with high accuracy by using a general and simple formula without being restricted by the conditions of the reference battery.

[0079] According to one embodiment, the control unit 120 may be configured to diagnose the state of the target battery by comparing the lithium charge amount with a preset reference charge amount.

[0080] The preset reference charge amount may refer to the amount of lithium that is designed to be precharged into the negative electrode of the target battery in the prelithiation process.

[0081] The control unit 120 may calculate the amount of lithium charged in the target battery according to the above-described embodiment, compare the calculated amount of lithium charged with a preset reference amount of lithium charged, and diagnose the state of the target battery based on the comparison result.

[0082] Specifically, if the calculated lithium charge amount is less than a predetermined reference charge amount, the control unit 120 may determine that the amount of lithium charged to the target battery during the pre-lithiation process is insufficient compared to the design, and diagnose the target battery as a defective battery. Alternatively, if the calculated lithium charge amount is equal to or greater than a predetermined reference charge amount, the control unit 120 may determine that the amount of lithium charged to the target battery during the pre-lithiation process corresponds to the designed amount, and diagnose the target battery as a normal battery. Preferably, the control unit 120 may diagnose the target battery as a normal battery if the calculated lithium charge amount is equal to or greater than the predetermined reference charge amount and within a predetermined error range. According to one embodiment of the present invention, the pre-lithiation diagnosis device 100 can quantitatively confirm the amount of lithium charged in the pre-lithiation process without disassembling the target battery, thereby quickly and accurately determining whether the target battery is a normal battery manufactured to correspond to the designed amount of lithium.

[0083] Meanwhile, hereinafter, it will be described how the pre-lithiation diagnostic device 100 according to the present invention acquires a positive electrode target profile and a negative electrode target profile for a target battery in a non-destructive manner.

[0084] 4 is a diagram illustrating how a positive electrode target profile and a negative electrode target profile are generated from the full-cell profile Tf of the target battery. The x-axis of the graph in FIG. 4 represents SOC (%), and the y-axis represents voltage (V).

[0085] 4, the negative electrode reference profile Rn and the positive electrode reference profile Rp stored in the memory unit 110 are shown, and for ease of understanding, a full cell profile Rf of the reference battery, which is the difference between the negative electrode reference profile Rn and the positive electrode reference profile Rp, is also shown. Here, the full cell profile Rf of the reference battery does not necessarily need to be stored in the memory unit 110 in advance, because the control unit 120 can obtain the full cell profile Rf or data constituting the full cell profile Rf from the difference between the pre-stored negative electrode reference profile Rn and the pre-stored positive electrode reference profile Rp.

[0086] As shown in FIG. 1, the pre-lithiation diagnostic device 100 according to the embodiment may further include a measurement unit 130 configured to measure the voltage of the target battery.

[0087] The measurement unit 130 may be configured to measure the voltage of the target battery at a predetermined voltage measurement interval during the charging or discharging process of the battery. The measurement unit 130 may employ various voltage measurement techniques known at the time of filing of the present invention. For example, the measurement unit 130 may include a voltage sensor known at the time of filing of the present invention. In particular, a voltage sensor already provided in a battery pack including the target battery according to the present invention may be used as the measurement unit 130 according to the present invention.

[0088] The control unit 120 may be configured to generate a full cell profile Tf for the target battery based on the voltage measured by the measurement unit 130. That is, when the voltage is measured by the measurement unit 130, the measured voltage information may be transmitted from the measurement unit 130 to the control unit 120. Then, the control unit 120 may generate a full cell profile Tf indicating a correspondence relationship between voltage and capacity for the target battery to be diagnosed based on the transmitted voltage information. That is, the full cell profile Tf of the target battery means a profile indicating a one-to-one correspondence relationship between voltage and SOC for the entire SOC range of the target battery.

[0089] The control unit 120 may be configured to acquire the positive electrode target profile Tp and the negative electrode target profile Tn from the full-cell profile Tf. That is, the control unit 120 can non-destructively acquire the positive electrode target profile Tp and the negative electrode target profile Tn without disassembling the target battery in advance to acquire the profiles of the individual electrodes (the positive electrode target profile Tp and the negative electrode target profile Tn).

[0090] Specifically, the control unit 120 may adjust the positive electrode reference profile Rp and the negative electrode reference profile Rn to correspond to the full cell profile Tf of the target battery.

[0091] For ease of understanding, the full cell profile Rf of the reference battery and the full cell profile Tf of the target battery are both shown in FIG. 4. The control unit 120 may adjust the positive electrode reference profile Rp and the negative electrode reference profile Rn to correspond to the full cell profile Tf of the target battery by shifting them in the x-axis direction or by shrinking and / or expanding them. That is, since the difference between the positive electrode reference profile Rp and the negative electrode reference profile Rn is the full cell profile Rf of the reference battery, the control unit 120 may adjust the positive electrode reference profile Rp and the negative electrode reference profile Rn so that the full cell profile Rf of the reference battery and the full cell profile Tf of the target battery correspond to each other.

[0092] Specifically, the correspondence between the full cell profile Rf of the reference battery and the full cell profile Tf of the target battery may mean that the outlines of the two profiles are similar. For example, the control unit 120 may obtain an adjusted positive electrode reference profile and an adjusted negative electrode reference profile that minimize the error between the two profiles. Alternatively, the control unit 120 may generate multiple adjusted positive electrode reference profiles and adjusted negative electrode reference profiles by varying the degree of shift and the degree of contraction and / or expansion in the x-axis direction. The control unit 120 may determine, from the multiple adjusted positive electrode reference profiles and adjusted negative electrode reference profiles generated, an adjusted positive electrode reference profile and an adjusted negative electrode reference profile that minimize the root mean square error (RMSE) with the full cell profile Tf of the target battery. The full cell profile of the reference battery, which is the difference between the determined adjusted positive electrode reference profile and the adjusted negative electrode reference profile, may be said to have the outline most similar to the full cell profile Tf of the target battery. Therefore, the control unit 120 can obtain the determined adjusted positive electrode reference profile and adjusted negative electrode reference profile as the above-described positive electrode target profile Tp and negative electrode target profile Tn. In this manner, the control unit 120 can obtain the positive electrode target profile Tp and negative electrode target profile Tn by adjusting the positive electrode reference profile Rp and the negative electrode reference profile Rn in a simple and easy manner without disassembling and analyzing the target battery.

[0093] Furthermore, the pre-lithiation diagnostic device 100 according to the present invention may be provided in a battery manufacturing apparatus. That is, the battery manufacturing apparatus may include at least some of the components of the pre-lithiation diagnostic device 100 according to the present invention. For example, the battery manufacturing apparatus may include the control unit 120 according to the present invention. The battery manufacturing apparatus may be configured to manufacture target batteries and verify the performance of the manufactured target batteries before they are shipped.

[0094] The battery manufacturing process may include an electrode manufacturing process for manufacturing electrodes, an assembly process for assembling the manufactured electrodes, and an activation process for imparting electrical properties to the assembled battery (target battery) by charging and discharging. In various embodiments, the battery manufacturing process may further include the prelithiation process described above.

[0095] The battery manufacturing apparatus can diagnose whether the pre-lithiation process was successfully performed in the above-described manner without disassembling the manufactured target battery after the assembly process or activation process, i.e., before the battery is shipped. That is, the battery manufacturing apparatus quantitatively calculates the amount of lithium supplied to the negative electrode and the amount of lithium charged through the pre-lithiation process to determine whether the pre-lithiation process was successfully performed, and can diagnose a defect in the target battery based on the results. Therefore, the battery manufacturing apparatus can diagnose the condition of the target battery in a simple manner without disassembling the target battery, thereby providing high reliability in the battery condition.

[0096] 5 is a flow chart illustrating a method for diagnosing prelithiation according to an embodiment of the present invention. In FIG. 5, the subject of each step may be each component of the prelithiation diagnosis device 100 according to the present invention.

[0097] Referring to FIG. 5, the pre-lithiation diagnostic method according to the present invention may include a step of acquiring a target profile (S510), a step of recognizing a target starting value (S520), and a step of determining a lithium charge amount (S530).

[0098] The target profile acquisition step S510 is a step of acquiring a positive target profile Tp and a negative target profile Tn for a target battery to be diagnosed, and may be performed by the control unit 120.

[0099] In one example, the control unit 120 may obtain a positive target profile Tp and a negative target profile Tn stored in advance in the memory unit 110.

[0100] Preferably, the control unit 120 may separate and acquire the positive and negative target profiles Tp and Tn from the full-cell profile indicating the voltage of the target battery. This has the advantages of not requiring a large memory capacity because the target profile does not need to be stored in advance in the memory unit 110, and of non-destructively acquiring the negative and positive target profiles Tn and Tp from the full-cell profile without disassembling the target battery to acquire the negative and positive target profiles Tn and Tp.

[0101] Specifically, the control unit 120 may receive voltage information indicating the voltage of the target battery from the measurement unit 130 configured to measure the voltage of the target battery. The control unit 120 may generate a full-cell profile for the target battery based on the measured voltage. An embodiment in which the control unit 120 obtains the positive electrode target profile Tp and the negative electrode target profile Tn from the full-cell profile has already been described with reference to FIG. 4, so a duplicated description will be omitted.

[0102] The target start value recognition step S520 is a step of recognizing a positive target start value and a negative target start value from the positive target profile Tp and the negative target profile Tn, and may be performed by the control unit 120.

[0103] Specifically, the positive target start value and the negative target start value may refer to the positive electrode characteristic value and the negative electrode characteristic value when the target battery corresponds to a predetermined SOC. Specifically, the positive target start value may refer to the positive electrode SOC or the positive electrode voltage value when the target battery corresponds to a predetermined SOC, and the negative target start value may refer to the negative electrode SOC or the negative electrode voltage value when the target battery corresponds to the predetermined SOC. Information related to the negative target start value and the positive target start value may be stored in the memory unit 110 in the form of a mapping table. In one embodiment, when the SOC of the target battery is 0%, the control unit 120 may recognize the negative target start value corresponding to the negative electrode SOC and the positive target start value corresponding to the positive electrode SOC.

[0104] The lithium charge amount determination step S530 may be performed by the control unit 120 as a step of determining the lithium charge amount pre-charged in the target battery through a pre-lithiation process based on at least one of the positive electrode reference starting value and the negative electrode reference starting value for the reference battery and the positive electrode target starting value and the negative electrode target starting value for the target battery.

[0105] The positive and negative reference start values ​​may refer to the positive and negative characteristic values ​​when the reference battery corresponds to a predetermined SOC. In one embodiment, the positive reference start value may refer to the positive SOC or positive voltage value when the reference battery corresponds to a predetermined SOC, and the negative reference start value may refer to the negative SOC or negative voltage value when the reference battery corresponds to the predetermined SOC. Information related to the negative and positive reference start values ​​may be stored in the memory unit 110 in the form of a mapping table. Here, the SOC of the reference battery for obtaining the positive and negative reference start values ​​may be the same as the SOC of the target battery for obtaining the positive and negative target start values.

[0106] The control unit 120 may calculate at least two parameters selected from a positive electrode reference starting value, a negative electrode reference starting value, a positive electrode target starting value, and a negative electrode target starting value, and calculate the lithium charge amount for the target battery pre-charged in the pre-lithiation process.

[0107] In one embodiment, the control unit 120 may calculate the lithium charge amount for the target battery based on the formula "|negative electrode reference start value-negative electrode target start value|" or a third difference corresponding to the difference between the first difference corresponding to "|negative electrode reference start value-positive electrode reference start value|" and the second difference corresponding to "|negative electrode target start value-positive electrode target start value|". As described above, the calculation of the lithium charge amount based on the formula and the load amount of the target battery will not be described in detail.

[0108] The contents of the pre-lithiation diagnosis device 100 according to the present invention described above may be applied to steps S510 to S530 in the same or similar manner. Therefore, detailed descriptions of each step of the pre-lithiation diagnosis method according to the present invention will be omitted.

[0109] The embodiments of the present invention described above are not necessarily embodied through devices and methods, but may be embodied through a program that realizes functions corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation should be easily embodied by a person skilled in the art to which the present invention pertains from the description of the above-mentioned embodiments.

[0110] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and various modifications and variations can be made by a person having ordinary skill in the art to which the present invention pertains within the technical spirit of the present invention and the scope of the claims.

[0111] Furthermore, since the above-mentioned present invention can be variously replaced, modified, and changed by a person having ordinary knowledge in the technical field to which the present invention belongs without departing from the technical concept of the present invention, it is not limited to the above-mentioned embodiments and the attached drawings, and can be configured by selectively combining all or part of each embodiment to make various modifications. [Explanation of symbols]

[0112] 100 Prelithiated diagnostic device 110 Memory section 120 control section 130 Measuring section

Claims

1. a memory unit for storing a reference positive electrode start value and a reference negative electrode start value for the reference battery; a control unit configured to acquire a positive electrode target profile and a negative electrode target profile for a target battery to be diagnosed, recognize a positive electrode target start value and a negative electrode target start value from the positive electrode target profile and the negative electrode target profile, and determine a lithium charge amount for a pre-lithiation process for the target battery based on at least one of the positive electrode reference start value, the negative electrode reference start value, the positive electrode target start value, and the negative electrode target start value.

2. The control unit 2. The pre-lithiation diagnostic device of claim 1, configured to determine the lithium charge amount based on the negative electrode reference start value and the negative electrode target start value.

3. The control unit 3. The pre-lithiation diagnostic device according to claim 2, configured to calculate a difference between the negative electrode reference start value and the negative electrode target start value, and determine the lithium charge amount based on the calculated difference and a preset positive electrode load amount.

4. The control unit 2. The pre-lithiation diagnostic device of claim 1, configured to determine the lithium charge amount based on a first difference that is a difference between the negative electrode reference start value and the positive electrode reference start value and a second difference that is a difference between the negative electrode target start value and the positive electrode target start value.

5. The control unit 5. The pre-lithiation diagnostic device according to claim 4, configured to calculate a third difference which is the difference between the first difference and the second difference, and to determine the lithium charge amount based on the calculated third difference and a preset positive electrode load amount.

6. The reference battery is 2. The prelithiation diagnostic device of claim 1, wherein the prelithiation step includes a battery in which no lithium is charged or a predetermined amount of lithium is charged.

7. The positive electrode reference start value and the negative electrode reference start value are 2. The pre-lithiation diagnostic device of claim 1, configured to be set to the positive electrode SOC and the negative electrode SOC of the reference battery when the SOC of the reference battery corresponds to a preset reference SOC.

8. a measuring unit configured to measure a voltage of the target battery; The control unit 2. The prelithiation diagnostic device according to claim 1, configured to generate a full cell profile for the target battery based on the voltage measured by the measurement unit, and to obtain the positive electrode target profile and the negative electrode target profile from the full cell profile.

9. The memory unit configured to store a positive electrode reference profile and a negative electrode reference profile for the reference battery; The control unit 9. The prelithiation diagnostic device of claim 8, configured to adjust the positive electrode reference profile and the negative electrode reference profile to correspond to the full-cell profile to obtain the positive electrode target profile and the negative electrode target profile, respectively.

10. The control unit 2. The pre-lithiation diagnostic device according to claim 1, configured to compare the lithium charge amount with a preset reference charge amount and diagnose the state of the target battery based on the comparison result.

11. A battery manufacturing apparatus comprising the prelithiation diagnostic device of any one of claims 1 to 10.

12. a target profile acquisition step of acquiring a positive target profile and a negative target profile for a target battery to be diagnosed; a target start value recognition step of recognizing a positive target start value and a negative target start value from the positive target profile and the negative target profile; determining a lithium charge amount for a pre-lithiation process for the target battery based on at least one of a positive electrode reference starting value, a negative electrode reference starting value, the positive electrode target starting value, and the negative electrode target starting value for a reference battery.

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