KR-20260064877-A - METHOD FOR CHECKING THE LIMIT CURRENT DENSITY OF BATTERY AND THE APPARATUS

KR20260064877AKR 20260064877 AKR20260064877 AKR 20260064877AKR-20260064877-A

Abstract

A method for determining a battery limit current density according to one embodiment of the present disclosure may include: (a) a step of generating a magnetic field in a battery by applying a first current to the battery; (b) a step of generating a magnetic field in a conductor sheet by applying a current of the same magnitude as the first current in the opposite direction to the first current to a conductor sheet of the same magnitude as the electrode of the battery; (c) a step of obtaining a magnetic field image by measuring the magnetic fields generated in the battery and the conductor sheet, respectively; (d) a step of checking whether cancelling occurs by superimposing the magnetic field image obtained from the battery and the magnetic field image obtained from the conductor sheet; and (e) a step of determining whether the battery has reached a limit current density based on a specific current point in time when the magnetic field image is canceled.

Inventors

정대현
김영석

Assignees

에스케이온 주식회사

Dates

Publication Date: 20260508
Application Date: 20241030

Claims (17)

Regarding the method for verifying the battery limit current density, (a) a step of generating a magnetic field in the battery by applying a first current to the battery; (b) a step of generating a magnetic field in a conductor sheet by applying a current of the same magnitude as the first current in the opposite direction to the first current to a conductor sheet of the same magnitude as the electrode of the battery; (c) A step of measuring the magnetic fields generated in the battery and the conductor sheet, respectively, to obtain respective magnetic field images; (d) a step of checking whether cancelling occurs by superimposing the magnetic field image obtained from the battery and the magnetic field image obtained from the conductor sheet; (e) a step of determining whether the battery has reached a limit current density based on a specific current point in time when the magnetic field image is canceled; a method for determining the limit current density of a battery.
In paragraph 1, A method for determining the limit current density of a battery, comprising the process of applying a second current higher than the first current to charge the battery when canceling is confirmed in step (d) above.
In paragraph 2, A method for determining the limit current density of a battery, comprising the process of determining the current density calculated from the current as the limit current density of the battery when, in step (e) above, an image that is not canceled is confirmed by repeating steps (a) through (d) for the second current.
In paragraph 1, In step (c) above, the magnetic field image is generated by a magnetic field image sensor, and The above magnetic field image is a method for verifying the limit current density of a battery used to visualize the internal current flow of the battery.
In paragraph 1, The above step (d) is a method for determining the limit current density of a battery, comprising the process of analyzing whether magnetic field canceling is performed in real time, tracking the internal current flow of the battery in real time, and visually representing it.
In paragraph 1, The above step (e) is a method for determining the limit current density of a battery, comprising a process of adjusting the charging speed when the limit current density of the battery is reached so that the battery does not exceed the limit current density.
In paragraph 1, A method for determining the limit current density of a battery, comprising the process of detecting non-uniformity of current density within the battery in step (e) above and adjusting the charging current to equalize the current distribution based thereon.
In paragraph 1, A method for determining the limit current density of a battery, comprising the process of monitoring the internal temperature change of the battery in step (e) above and adjusting the charging speed to prevent current density non-uniformity due to temperature rise.
In a device for verifying the limit current density of a battery, A battery current application unit that applies a first current to a battery to generate a magnetic field in the battery; A conductor current application unit that generates a magnetic field in a conductor sheet by applying a current of the same magnitude as the first current in the opposite direction to the first current to a conductor sheet of the same magnitude as the electrode of a battery; A magnetic field image sensor that measures the magnetic field generated from the battery and conductor sheet to acquire respective magnetic field images; An image processing unit that checks whether canceling is possible by superimposing a magnetic field image obtained from the battery and a magnetic field image obtained from the conductor sheet; A battery limit current density checking device comprising: a control unit that determines whether the battery has reached a limit current density based on a specific current point in time when the magnetic field image is canceled.
In Paragraph 9, If cancellation is confirmed in the above image processing unit, A battery limit current density verification device in which a battery is charged by applying a second current higher than the first current.
In Paragraph 10, The above control unit is a battery limit current density checking device that continuously checks whether the second current is canceled, and if an image that is not canceled is confirmed, determines that the current density calculated from the current is the battery limit current density.
In Paragraph 9, The magnetic field image generated by the above magnetic field image sensor is, A battery limit current density verification device used to visualize the internal current flow of a battery.
In Paragraph 9, The above image processing unit analyzes whether magnetic field canceling is performed in real time, tracks the internal current flow of the battery in real time, and visually displays the limit current density of the battery.
In Paragraph 9, The above image processing unit is a battery limit current density verification device that performs the function of visually representing a problem area of the battery by analyzing the image when a non-canceled magnetic field image appears after checking whether cancellation is performed.
In Paragraph 9, The above control unit is a battery limit current density checking device that controls the battery so as not to exceed the limit current density by adjusting the charging speed when the battery reaches the limit current density.
In Paragraph 9, The above conductor sheet is a battery limit current density verification device formed to correspond to the electrode and lead boundary of the battery cell.
In Paragraph 9, The above battery limit current density verification device is, The battery and the conductor sheet are aligned, and a shielding sheet is provided between them, and A battery limit current density verification device that places the magnetic field image sensor on the upper part of the battery, and moves the magnetic field image sensor in a unidirectional direction parallel to the current direction applied to the battery and the conductor sheet to acquire magnetic field images of each of the battery and the conductor sheet.

Description

Method for Checking the Limit Current Density of a Battery and the Apparatus The present disclosure relates to a method and apparatus for determining the limit current density of a battery using a magnetic field imaging technique. Due to their high energy density and charge/discharge efficiency, lithium-ion batteries are widely used in fields ranging from various portable electronic devices to electric vehicles (EVs) and energy storage systems (ESS). While the demand for charging speeds is surging due to recent advancements in battery technology, issues regarding battery performance and safety during rapid charging are emerging as new challenges. During rapid charging, the current inside the battery may become concentrated in certain areas or distributed unevenly. This negatively affects battery life and degrades battery performance in the long run. In particular, when the battery reaches its limit current density during rapid charging, excessive heat generation inside the battery and material damage can lead to reduced battery life and safety issues. Against this backdrop, it is essential to accurately monitor the battery's current density, charge state, and internal current distribution to maintain stability. Conventional monitoring methods include measuring changes in battery current and voltage using current and voltage sensors, or using temperature sensors to detect heat generated during charging and prevent battery overheating. Additionally, methods such as using X-ray CT to image the internal structure of the battery and identify internal defects are also used. However, existing technology has limitations in monitoring current flow within a battery in real time. In other words, existing technology is limited in accurately measuring the battery's current density and distribution, or in determining the battery's limiting current density based on this. In particular, accurately determining whether the battery has reached its limit current density during rapid charging is crucial for ensuring the battery's safety and lifespan. FIG. 1 illustrates a method for determining the limit current density of a battery according to one embodiment of the present disclosure. FIG. 2 illustrates a method for determining the limit current density of a battery according to another embodiment of the present disclosure. FIG. 3 illustrates a device for verifying the limit current density of a battery according to one embodiment of the present disclosure. FIG. 4 illustrates a device for verifying the limit current density of a battery according to another embodiment of the present disclosure. FIG. 5 is a schematic representation of an example of a device for verifying the limit current density of a battery according to one embodiment of the present disclosure. FIG. 6 shows data confirming whether a magnetic field image is canceled, measured according to a comparative example and an embodiment of the present disclosure. FIG. 7 is a drawing illustrating an electric vehicle that uses a method for verifying the limit current density of a battery according to one embodiment of the present disclosure and includes a device for verifying the limit current density of a battery. Hereinafter, the present disclosure will be described in detail with reference to the attached drawings. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively. Although terms such as "first," "second," etc. are used to describe various elements, components, and/or sections, it goes without saying that these elements, components, and/or sections are not limited by these terms. These terms are used merely to distinguish one element, component, or section from another. Accordingly, the first element, first component, or first section mentioned below may, within the technical scope of the present disclosure, be a second element, second component, or second section. The terms used herein are for describing the embodiments and are not intended to limit the disclosure. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and/or "made of" do not exclude the presence or addition of one or more other components, steps, actions, and/or elements to the mentioned components, steps, actions, and/or elements. Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which this disclosure pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. FIG. 1 illustrates a method for determining the limit current density of a battery according to one embodiment of the present disclosure, and FIG. 2 illustrates a method for determining the limit current density of a battery according t