EP-4742362-A2 - SECONDARY BATTERY DIAGNOSING APPARATUS AND METHOD

EP4742362A2EP 4742362 A2EP4742362 A2EP 4742362A2EP-4742362-A2

Abstract

Disclosed is a secondary battery diagnosing technology capable of effectively diagnosing a state of a secondary battery using a charge and discharge signal of the secondary battery. The secondary battery diagnosing apparatus includes a memory unit configured to store a positive electrode reference profile and a negative electrode reference profile for charge or discharge of a reference battery; a voltage measuring unit configured to measure a voltage of a target battery during a charge or discharge process; and a processor configured to generate a charge and discharge measurement profile based on the voltage measured by the voltage measuring unit, compare a simulation profile obtained from the positive electrode reference profile and the negative electrode reference profile stored in the memory unit with the generated charge and discharge measurement profile, and determine a positive electrode adjustment profile and a negative electrode adjustment profile so that an error between the simulation profile and the charge and discharge measurement profile is within a predetermined level.

Inventors

CHOI, SOON-JU
KIM, DAE-SOO
KIM, YOUNG-DEOK
JEE, Su-Won
CHOI, HYUN-JUN

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260513
Application Date: 20211203

Claims (11)

A storage medium (100) storing a computer program that, when executed by the processor (300) of a secondary battery diagnosing apparatus, causes the secondary battery diagnosing apparatus to: generate (S130) a charge and discharge measurement profile based on voltage measurements of a target battery; compare (S140) a simulation profile obtained from a positive electrode reference profile and a negative electrode reference profile for charge or discharge of a reference battery stored in a memory unit (100) with the charge and discharge measurement profile generated in the generating step; and determining (S150) a positive electrode adjustment profile and a negative electrode adjustment profile by adjusting the positive electrode reference profile and/or the negative electrode reference profile so that an error between the simulation profile and the charge and discharge measurement profile is within a predetermined level.
The storage medium (100) according to claim 1, wherein execution of the computer program causes the secondary battery diagnosing apparatus to determine the positive electrode adjustment profile and the negative electrode adjustment profile by moving at least one of the positive electrode reference profile and the negative electrode reference profile in a horizontal direction.
The storage medium (100) according to claim 1 or 2, wherein execution of the computer program causes the secondary battery diagnosing apparatus to determine the positive electrode adjustment profile and the negative electrode adjustment profile by adjusting a scale of at least one of the positive electrode reference profile and the negative electrode reference profile in a horizontal direction.
The storage medium (100) according to one of claims 1 to 3, wherein execution of the computer program causes the secondary battery diagnosing apparatus to: measure a full discharge voltage and a full charge voltage of the target battery, and estimate a positive electrode starting value of the positive electrode adjustment profile or a negative electrode starting value of the negative electrode adjustment profile based on the full discharge voltage and estimate a positive electrode final value of the positive electrode adjustment profile and a negative electrode final value of the negative electrode adjustment profile based on the full charge voltage.
The storage medium (100) according to claim 4, wherein execution of the computer program causes the secondary battery diagnosing apparatus to identify a capacity of the target battery based on a difference between the positive electrode final value and the positive electrode starting value or a difference between the negative electrode final value and the negative electrode starting value.
The storage medium (100) according to one of claims 1 to 5, wherein execution of the computer program causes the secondary battery diagnosing apparatus to check how much each point where the capacity is 0 in the positive electrode reference profile and the negative electrode reference profile is moved in the capacity axis direction in the positive electrode adjustment profile and the negative electrode adjustment profile.
The storage medium (100) according to one of claims 1 to 6, wherein execution of the computer program causes the secondary battery diagnosing apparatus to: when the error between the simulation profile and the charge and discharge measurement profile is reduced by moving the simulation profile in parallel in a vertical direction, which is a voltage axis direction in a capacity-voltage graph, identify whether an internal resistance of the target battery increases by using the parallel movement result.
A secondary battery diagnosing apparatus, comprising: a storage medium (100) according to one of claims 1 to 7 that stores a computer program that; and a processor (300) configured to execute the computer program stored on the storage medium (100).
A battery pack, comprising the secondary battery diagnosing apparatus according to claim 8.
A vehicle, comprising the secondary battery diagnosing apparatus according to claim 8.
A secondary battery diagnosing method, comprising: measuring (S120) a voltage of a target battery while charging or discharging the target battery; generating (S130) a charge and discharge measurement profile based on the voltage measured in the voltage measuring step; comparing (S140) a simulation profile obtained from a positive electrode reference profile and a negative electrode reference profile for charge or discharge of a reference battery stored in a memory unit (100) with the charge and discharge measurement profile generated in the generating step; and determining (S150) a positive electrode adjustment profile and a negative electrode adjustment profile so that an error between the simulation profile and the charge and discharge measurement profile is within a predetermined level.

Description

TECHNICAL FIELD The present application claims priority to Korean Patent Application No. 10-2020-0184944 filed on December 28, 2020 in the Republic of Korea, the disclosures of which are incorporated herein by reference. The present disclosure relates to a secondary battery diagnosing technology, and more particularly, to a battery diagnosing technology capable of effectively diagnosing a state of a secondary battery using a charge and discharge signal of the secondary battery. BACKGROUND ART Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium secondary batteries, and the like. Among them, the lithium secondary batteries are spotlighted because they ensure free charging and discharging due to substantially no memory effect compared to nickel-based secondary batteries, as well as very low discharge rate and high energy density. Moreover, recently, secondary batteries have been widely used for driving or energy storage in medium and large-sized devices such as electric vehicles or energy storage systems (ESS). In addition, for this reason, the interest in secondary batteries is further increased, and related research and development are being made more actively. The lithium secondary battery mainly uses lithium-based oxide and carbon material as positive electrode active material and negative electrode active material, respectively. Also, the lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate respectively coated with a positive electrode active material and a negative electrode active material are arranged with a separator interposed therebetween, and an exterior, namely a battery case, for hermetically receiving the electrode assembly together with electrolyte. A secondary battery, namely a battery, generates electrical energy through electrochemical oxidation and reduction reactions. However, as the charge/discharge cycle is repeated, the secondary battery does not maintain the capacity at the time of initial manufacture, namely the performance in a BOL (Beginning Of Life) state, and may be degraded over time. If the degradation state of the secondary battery is not properly understood, it may be difficult to accurately predict the state of charge (SOC), usable time, lifespan, replacement timing, or the like of the battery. In addition, if the prediction is not made accurately in this aspect, it may cause unexpected damage to a user or manager of the secondary battery. Moreover, defective batteries may occur in the process of manufacturing secondary batteries. For example, among many manufactured batteries, secondary batteries that do not have the capacity or use area as designed due to process errors may appear. Even if such a defective secondary battery is unavoidably manufactured, it is necessary to ensure that the defective secondary battery is not shipped to the outside through inspection. Or, even if the defective secondary battery is shipped to the outside, it is desirable to receive a defective diagnosis at the beginning of use of the defective secondary battery. In this regard, various techniques for diagnosing the degree of degradation during use of the secondary battery or whether there is a defect during the manufacture of the secondary battery have been proposed. However, in the case of the diagnostic techniques proposed so far, there are several problems, such as a relatively complex calculation method or low accuracy. Therefore, there is still a need for an efficient secondary battery diagnosis technology that is simpler and more accurate. DISCLOSURE TECHNICAL PROBLEM The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a secondary battery diagnosing apparatus and method, which may diagnose a state of a secondary battery using a charge and discharge signal extracted from the secondary battery, and a battery pack including the diagnosing apparatus. These and other objects and advantages of the present disclosure may be understood from the following detailed description and will become more fully apparent from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure may be realized by the means shown in the appended claims and combinations thereof. TECHNICAL SOLUTION In one aspect of the present disclosure, there is provided a secondary battery diagnosing apparatus, comprising: a memory unit configured to store a positive electrode reference profile and a negative electrode reference profile for charge or discharge of a reference battery; a voltage measuring unit configured to measure a voltage of a target battery during a charge or discharge process; and a processor configured to generate a charge and discharge measurement profile based on the voltage measured by the