KR20170062133A

KR20170062133A - Battery charging method

Info

Publication number: KR20170062133A
Application number: KR1020150167592A
Authority: KR
Inventors: 이현원; 이현화; 김동현
Original assignee: 주식회사 엘지화학
Priority date: 2015-11-27
Filing date: 2015-11-27
Publication date: 2017-06-07

Abstract

The present invention discloses a battery charging method of a battery device. According to an embodiment of the present invention, there is provided a method of charging a battery, comprising: performing a first constant current charge on the battery device with a first reference current; when the battery device reaches a first reference voltage by the first constant current charge, Performing a first constant voltage charging with respect to the battery device at the first reference voltage when the charging current for the battery device reaches the second reference current by the first constant voltage charging, Performing a second constant-current charge on the battery device when the battery device reaches a second reference voltage by the second constant-current charge, performing a second constant-voltage charge on the battery device with the second reference voltage .

Description

Battery Charging Method {BATTERY CHARGING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a battery charging method, and more particularly, to a battery charging method capable of shortening a charging time of a battery while extending the service life of the battery.

Because of the high initial investment costs of large capacity, high power batteries for energy storage systems, it is efficient to improve the existing methodology for studying longer battery life.

Generally, a lithium-ion battery charging apparatus charges a battery by a constant current (CC) / constant voltage (CV) charging method. For example, when the battery voltage is 4.2V or less, which is the reference voltage (CC / CV inflection point), charging is performed with a constant current. When the battery voltage reaches the reference voltage according to charging, charging is performed at a constant voltage of 4.2V. Therefore, as shown in FIG. 1, the charging current curve is constant at a battery voltage of about 4.2 V or lower and constant current, and exponentially decreases when the battery voltage reaches 4.2 V. The charging voltage curve shows a 4.2 V inflection point It increases logarithmically in the center, and is maintained constant when it reaches 4.2V. When the charging current flowing through the battery gradually decreases and reaches a constant current value (for example, 0.05 C to 0.1 C), it is determined that the battery is fully charged and charging is stopped.

However, such a charging method has a disadvantage in that the charging time of the battery becomes longer due to the characteristics of the battery in the constant-voltage charging section, thereby increasing the total charging time. In addition, when applied to an energy storage system (ESS: Energy Storing System), excessive heat may be generated inside the battery cell because it is always connected to the power system, and the softening phenomenon of the positive electrode There is a problem that the life of the battery is shortened.

Disclosure of Invention Technical Problem [8] The present invention provides a new battery charging method capable of shortening the charging time of the battery while improving the battery charging method to prolong the life of the battery.

According to an embodiment of the present invention, there is provided a method of charging a battery, comprising: performing a first constant current charge on the battery device with a first reference current; when the battery device reaches a first reference voltage by the first constant current charge, Performing a first constant voltage charging with respect to the battery device at the first reference voltage when the charging current for the battery device reaches the second reference current by the first constant voltage charging, Performing a second constant-current charge on the battery device when the battery device reaches a second reference voltage by the second constant-current charge, performing a second constant-voltage charge on the battery device with the second reference voltage .

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned can be understood by those skilled in the art from the following description.

The battery charging method according to the present invention can shorten the charging time of the battery while extending the service life of the battery.

FIG. 1 is a graph showing changes in charging current and charging voltage value when a battery is charged by a general constant current / constant voltage charging method.
FIG. 2 is a flowchart illustrating a method of charging a battery according to an embodiment of the present invention; FIG.
3 is a graph showing changes in charge current and charge voltage value when the battery is charged by the charge method according to an embodiment of the present invention.
FIG. 4 is a graph showing changes in charge current and charge voltage when a conventional CC / CC / CC / CV battery is charged.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

FIG. 2 is a flowchart illustrating a method of charging a battery according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating a method of charging a battery according to an embodiment of the present invention. Graph.

Referring to FIGS. 2 and 3, the battery charging apparatus first measures the charging state of the battery device to be charged and confirms the initial charging voltage (step 202).

When the initial charging voltage of the battery is smaller than the predetermined first reference voltage, the battery charging device performs constant current charging with a predetermined first reference current as the constant current value until the battery device reaches the first reference voltage 204).

At this time, the first reference voltage may be 3.9V and the first reference current may be 2C-rate. During the constant current charging, the voltage of the battery device gradually increases. Therefore, the battery charging device continuously measures and confirms the voltage change of the battery device while the constant current charging is performed.

When the voltage of the battery device reaches the first reference voltage (step 206), the battery charging device switches the charging mode from the constant current mode to the constant voltage mode to perform the constant voltage charging with the first reference voltage as the constant voltage value for the battery device (Step 208).

During such constant voltage charging, the charging current for the battery device gradually decreases. Therefore, the battery charging device constantly measures and confirms the change of the charging current with respect to the battery device while the constant-voltage charging is performed.

When the charging current for the battery device reaches the predetermined second reference current (step 210), the battery charging device performs constant current charging with the constant current value as the second reference current after the constant voltage charging is cut off ( Step 212).

At this time, the second reference current may be set to 10% to 90% of the first reference current. As described above, in the present invention, the constant current charging is performed in the next step with the current value equal to the cutoff current (second reference current) in the constant voltage charging, so that the battery device can be charged without impact.

When the voltage of the battery device gradually increases to reach a predetermined second reference voltage (step 214) by performing the constant current charging with the second reference current, the battery charging device switches the charging mode from the constant current mode to the constant voltage mode, A constant voltage charging is performed with the second reference voltage as a constant voltage value (step 216).

At this time, the second reference voltage may be 4.2V.

When the charging current for the battery device gradually decreases to reach a predetermined third reference current (step 218) by performing the constant voltage charging with the second reference voltage, the battery charging device turns off the constant voltage charging, The constant current charging is performed at a constant current value (step 220).

At this time, the third reference current may be set to 10% to 90% of the second reference current.

When the voltage of the battery device gradually increases to reach a preset third reference voltage by performing the constant current charging with the third reference current (step 222), the battery charging device switches the charging mode from the constant current mode to the constant voltage mode, (Step 224) with the third reference voltage as a constant voltage value.

At this time, the third reference voltage may be 4.35V.

When the charging current for the battery device gradually decreases to reach a predetermined fourth reference current by performing the constant voltage charging with the third reference voltage, the battery charging device ends the charging for the battery device (step 226).

In this case, the fourth reference current may be set to 1/5 to 1/40 of the third reference current.

FIG. 4 is a graph showing changes in charge current and charge voltage value when the battery is charged by the conventional CC / CC / CC / CV method. Comparing the graphs of FIGS. 3 and 4, it can be seen that the charging method according to the present invention can shorten the charging time by about 20% compared with the conventional CC / CC / CC / CV method in buffering the battery have.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims

A battery charging method for a battery charging device,
Performing a first constant current charge on the battery device with a first reference current;
Performing a first constant voltage charging on the battery device with the first reference voltage when the battery device reaches a first reference voltage by the first constant current charging;
Performing a second constant current charge on the battery device with the second reference current when the charging current for the battery device reaches the second reference current by the first constant voltage charging; And
And performing a second constant voltage charging on the battery device with the second reference voltage when the battery device reaches a second reference voltage by the second constant current charging.

The method of claim 1, wherein the second reference current
Wherein the first reference current has a magnitude of 10% to 90% of the first reference current.

The method according to claim 1,
Performing a third constant current charge on the battery device with the third reference current when the charging current for the battery device reaches the third reference current by the second constant voltage charging; And
And performing a third constant voltage charging on the battery device with the third reference voltage when the battery device reaches the third reference voltage by the third constant current charging.

4. The method of claim 3, wherein the third reference current
Wherein the second reference current has a magnitude of 10% to 90% of the second reference current.

The method of claim 3,
And charging is terminated when the charging current for the battery device reaches the fourth reference current by the third constant voltage charging.

6. The method of claim 5, wherein the fourth reference current
Wherein the third reference current has a magnitude of 1/5 to 1/40 of the third reference current.