JP7076191B2 - Battery charging method and equipment - Google Patents

Description

The present invention relates to a battery charging method and an apparatus.

There are various ways to charge the battery. For example, the constant current-constant voltage (CCCV) charge the battery with a constant current, and when the battery voltage reaches a preset voltage, the battery is charged with a constant voltage. As a different example, the current attenuation charging method charges the battery with a high current at a low SOC (System of Charge) and gradually reduces the current at a specific SOC.

Further, as a battery charging method, a quick charging method that reduces the charging time of the battery can be mentioned. Repeated fast charging can reduce battery life.

An object of the present invention is to provide a battery charging method and an apparatus.

The battery charging method according to one aspect includes a step of charging the battery with a charging current and a step of changing the charging current when a current changing event occurs during the charging of the battery. It occurs when the battery reaches a threshold voltage at which the negative potential of the battery becomes a reference value.

The battery charging method may further include a step of confirming the threshold voltage corresponding to the charging current with reference to a table in which the threshold voltage and the charging current are stored.

The battery charging method may further include substituting the table for a table corresponding to the changed life information when the battery life information changes.

The battery charging method further includes a step of ending the charging section corresponding to the charging current and a step of charging the battery with a current lower than the charging current in the subsequent charging section when the current change event occurs. Can include.

The battery charging method includes a step of charging the battery at a constant voltage when the battery reaches the maximum voltage, and a method of charging the battery when the charging current is reduced to the ending current while charging the battery at the constant voltage. It may further include a step of ending charging.

The reference value may be 0.075V to 0.73V.

The reference value may be 0.075V to 0.2V.

A battery charging device according to an embodiment includes a controller that charges a battery with a charging current and changes the charging current when a current change event occurs during the charging of the battery, wherein the current change event is the said. It occurs when the battery reaches a threshold voltage at which the negative electrode potential of the battery becomes a reference value.

The controller can confirm the threshold voltage corresponding to the charging current by referring to a table in which the threshold voltage and the charging current are stored.

The controller may replace the table with a table corresponding to the changed life information when the battery life information changes.

The controller may terminate the charging section corresponding to the charging current when the current change event occurs, and subsequently charge the battery with a current lower than the charging current in the charging section.

The controller charges the battery at a constant voltage when the battery reaches the maximum voltage, and terminates charging of the battery when the charging current decreases to the termination current while charging the battery at the constant voltage. obtain.

The reference value may be 0.075V to 0.73V.

The reference value may be 0.075V to 0.2V.

The battery charging device according to the other embodiment has a step of charging the battery to the first charging current value, and the first charging current value when the battery reaches a threshold voltage at which the negative electrode potential of the battery becomes a reference value. It includes a step of charging to a lower second charging current value.

The reference value may be 0.075V to 0.73V.

The reference value may be 0.075V to 0.2V.

The first charge current value may be 1.0 C-rate or higher.

The battery charging method may further include a step of confirming the threshold voltage corresponding to the first charging current value with reference to a table in which the first charging current value and the threshold voltage are stored.

The battery charging method may further include substituting the table for a table corresponding to the changed life information when the battery life information changes.

The battery charging method includes a step of charging the battery at a constant voltage when the battery reaches the maximum voltage, and a method of charging the battery when the charging current is reduced to the ending current while charging the battery at the constant voltage. It may further include a step of ending charging.

The battery system according to one embodiment charges the battery with a battery and an initial charge current in the first charge mode, and when the battery reaches a threshold voltage corresponding to the initial charge current, the battery system is described in the first charge mode. The threshold voltage includes a controller that changes the initial charge current to a charge current among the charge currents thereafter, and the threshold voltage includes a voltage at which the negative voltage of the battery reaches a reference value.

The controller may end charging in the first charging mode and charge the battery to a constant voltage in the second charging mode when the voltage of the battery reaches the maximum voltage.

The controller may terminate charging in the second charging mode when the charging current in the second charging mode is reduced to the termination current.

According to the present invention, it is possible to provide a battery charging method and an apparatus.

It is a figure for demonstrating the battery charging system which concerns on one Embodiment. It is a flowchart for demonstrating an example of the battery charging method which concerns on one Embodiment. It is a figure for demonstrating an example of the battery charging method which concerns on one Embodiment. It is a figure for demonstrating another example of the battery charging method which concerns on one Embodiment. It is a figure for demonstrating another example of the battery charging method which concerns on one Embodiment. It is a flowchart for demonstrating the threshold voltage determination method which concerns on one Embodiment. It is a figure for demonstrating the threshold voltage determination method which concerns on one Embodiment. It is a figure for demonstrating the threshold voltage determination method which concerns on one Embodiment. It is a figure for demonstrating the threshold voltage determination method which concerns on one Embodiment. It is a figure for demonstrating the threshold voltage determination method which concerns on one Embodiment. It is a flowchart for demonstrating another example of the threshold voltage determination method which concerns on one Embodiment. It is a figure for demonstrating another example of the threshold voltage determination method which concerns on one Embodiment. It is a block diagram for demonstrating the battery charging apparatus which concerns on one Embodiment. It is a block diagram for demonstrating the threshold voltage determination apparatus which concerns on one Embodiment. It is a figure for demonstrating the automobile which concerns on one Embodiment. It is a block diagram for demonstrating the terminal which concerns on one Embodiment.

Hereinafter, the description will be described in detail with reference to the drawings to which the embodiments are attached.

Various changes are made to the embodiments described below. The embodiments described below are not intended to be limited to embodiments and shall be understood as including all modifications, equivalents or alternatives thereof.

The terms used herein are merely used to describe a particular embodiment and are not intended to limit the invention. A singular expression also includes multiple expressions unless they have a distinctly different meaning in context. In the present specification, terms such as "include" or "have" indicate that the features, numbers, steps, operations, components, parts or combinations thereof described above exist. It must be understood as not prescribing the possibility of existence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

Unless defined differently, all terms used herein, including technical or scientific terms, shall be generally understood by those of ordinary skill in the art to which this embodiment belongs. Has the same meaning. Commonly used predefined terms should be construed as having a meaning consistent with the meaning in the context of the relevant technology, which is ideal or excessive unless expressly defined herein. Is not interpreted as a formal meaning.

Further, in the description with reference to the attached drawings, the same reference numerals are given to the same components regardless of the drawing reference numerals, and duplicate explanations thereof will be omitted. If it is determined in the description of the embodiment that the specific description of the relevant known art unnecessarily obscures the gist of the embodiment, the detailed description thereof will be omitted.

FIG. 1 is a diagram for explaining a battery system according to an embodiment.

Referring to FIG. 1, the battery system 100 includes a battery charging device 110 and a battery 120. The battery 120 indicates a battery cell, a battery module, or a battery pack.

The battery charging device 110 charges the battery 120 in a step charging mode. As a type of the quick charge mode of the step charge mode, a mode in which the battery charging device 110 charges the battery 120 while changing the charging current stepwise is shown.

When the battery 120 is charged, the negative electrode potential of the battery 120 becomes low due to an electrochemical phenomenon in the battery 120. If the battery 120 is continuously charged in a situation where the negative electrode potential of the battery 120 is low (for example, 0 V or less), a phenomenon that metal is plated on the electrodes of the battery 120 may occur. For example, in the case of a lithium ion battery, lithium plating may occur on the negative electrode. Such a phenomenon becomes a factor that shortens the life of the battery 120.

In order to prevent such a phenomenon, the battery charging device 110 according to the embodiment charges the battery 120 by changing the charging current each time a current change event occurs in the step charging mode. For example, when the voltage of the battery 120 reaches the threshold voltage, it is considered that a current change event occurs. The voltage of the battery 120 when the negative electrode potential of the battery 120 reaches the reference value is set as the threshold voltage. The reference value is set at a specific value or interval, and the threshold voltage prevents the negative electrode potential from becoming smaller than the reference value during charging, mitigates the phenomenon of metal plating on the negative electrode, and prevents deterioration of the battery 120. do.

The battery charging device 110 charges while gradually reducing the charging current each time the threshold voltage is reached. When the battery 120 voltage reaches the maximum voltage during charging in the step charging mode as described above, the battery charging device 110 charges the battery 120 in the constant voltage charging mode.

Hereinafter, the battery charging method of the battery charging device 110 will be specifically described with reference to FIGS. 2 to 4B.

2 and 3 are diagrams for explaining an example of the battery charging method according to the embodiment.

Referring to FIG. 2, the battery charging device 110 charges the battery 120 in the step charging mode (S210). When the step charging mode has the charging currents shown in Table 1 below, it is assumed that the battery charging device 110 charges the battery 120 at 1.2C-rate out of 1.2C-rate to 0.4C-rate.

バッテリ充電装置１１０は、充電電流を変更するために電流変更イベントが発生するかをモニタリングする（Ｓ２２０）。例えば、バッテリ充電装置１１０は、バッテリ１２０の電圧が充電電流１．２Ｃ－ｒａｔｅに対応する閾値電圧に達したかをモニタリングする。別の表現にすると、バッテリ充電装置１１０は、バッテリ１２０の電圧を充電電流１．２Ｃ－ｒａｔｅに対応する閾値電圧と比較する。ここで、１．２Ｃ－ｒａｔｅに対応する閾値電圧は、バッテリ１２０の負極電位が基準値となるバッテリ１２０の電圧として、バッテリ充電装置１１０は、充電電流と閾値電圧との間の対応関係が記録されている表（一例として、下記の表２）から１．２Ｃ－ｒａｔｅに対応する閾値電圧３．９７４Ｖを確認し、バッテリ１２０の電圧が閾値電圧３．９７４Ｖに達したかをモニタリングする。

The battery charging device 110 monitors whether a current change event occurs in order to change the charging current (S220). For example, the battery charging device 110 monitors whether the voltage of the battery 120 reaches the threshold voltage corresponding to the charging current 1.2C-rate. In other words, the battery charging device 110 compares the voltage of the battery 120 with the threshold voltage corresponding to the charging current 1.2C-rate. Here, the threshold voltage corresponding to 1.2C-rate is the voltage of the battery 120 in which the negative electrode potential of the battery 120 is a reference value, and the battery charging device 110 records the correspondence relationship between the charging current and the threshold voltage. The threshold voltage of 3.974V corresponding to 1.2C-rate is confirmed from the table (Table 2 below as an example), and it is monitored whether the voltage of the battery 120 reaches the threshold voltage of 3.974V.

基準値は、バッテリ１２０の負極に金属が導出される現象を防止又は最小化するために設定された値として、例えば、０．０７５Ｖ～０．７３Ｖ内の値、又は０．０７Ｖ～０．２Ｖ内の値であってよい。基準値はこれに制限されることはない。

The reference value is, for example, a value within 0.075V to 0.73V or 0.07V to 0.2V as a value set to prevent or minimize the phenomenon that metal is derived to the negative electrode of the battery 120. It may be a value within. The reference value is not limited to this.

If the current change event does not occur in step S220 (for example, if the voltage of the battery 120 is smaller than the threshold voltage 3.974V), the battery charging device 110 continues the battery 120 with a charging current of 1.2C-rate. And charge.

If a current change event occurs in step S220 (for example, if the voltage of the battery 120 reaches the threshold voltage 3.974V), the battery charging device 110 determines whether the voltage of the battery 120 is smaller than the maximum voltage. Check (S230). The maximum voltage varies depending on the type of the battery 120 as a voltage set to prevent the battery 120 from being overcharged. As an example, the maximum voltage of a lithium ion battery is within 4V to 4.2V. If it is not checked whether the voltage of the battery 120 is smaller than the maximum voltage, the battery 120 may be overcharged and an abnormality may occur in the battery 120, which shortens the life of the battery 120. Therefore, in order to prevent or minimize such an overcharge problem, the battery charging device 110 confirms whether or not the voltage of the battery 120 is smaller than the maximum voltage.

If the voltage of the battery 120 is smaller than the maximum voltage in step S230, the battery charging device 110 changes the charging current (S240). For example, the battery charging device 110 changes the charging current 1.2C-rate to 1.1C-rate. In other words, the battery charging device 110 ends the 1.2C-rate charging section and charges the battery 120 in the 1.1C-rate charging section.

The battery charging device 110 repeats steps S210 to S240 until the voltage of the battery 120 reaches the maximum voltage. FIG. 3 shows a voltage graph 310 of the battery 120 when the battery charging device 110 repeatedly performs steps S210 to S240. Referring to FIG. 3, the battery charging device 110 changes the charging current each time a current change event occurs until the voltage of the battery 120 reaches the maximum voltage.

When the voltage of the battery 120 reaches the maximum voltage in step S230, the battery charging device 110 charges the battery at a constant voltage (S250). In other words, the battery charging device 110 charges the battery 120 in the constant voltage charging mode. Here, the charging current gradually decreases over time, and eventually the charging current reaches a termination current (eg, 0.05 C-rate). The battery charging device 110 ends charging when the charging current reaches the end current (S260).

According to one embodiment, the charging in the step charging mode is controlled by the base of the threshold voltage, so that the negative electrode potential of the battery 120 is maintained above the reference value. Therefore, the phenomenon that the negative electrode of the battery 120 is plated with metal is alleviated, and the life characteristic of the battery 120 is improved.

4A and 4B are diagrams for explaining another example of the battery charging method according to the embodiment.

Referring to FIG. 4A, Tables 410, 420, and 430 corresponding to SOH (state of health), respectively, are shown. SOH is expressed separately from the life information.

The negative electrode potential characteristic of the battery 120 may change depending on the degree of deterioration of the battery 120, but the battery charging device 110 does not consider the degree of deterioration of the battery 120, and one table (as an example, Table 2 above) is continuously used. If the battery charging method is performed, a situation occurs in which the negative electrode potential becomes smaller than the reference value. Therefore, when the battery 120 deteriorates and the SOH decreases, the battery charging device 110 performs the battery charging method shown in FIG. 2 in the table corresponding to the reduced SOH. For example, the battery charging device 110 can perform the battery charging method in Table 410 when the battery 120 has SOH = 0.95, and substitutes Table 410 for Table 420 when SOH = 0.9. The battery charging method shown in FIG. 2 is performed. Further, if SOH = 0.85, the battery charging device 110 replaces Table 420 with Table 430 and performs the battery charging method shown in FIG.

Referring to FIG. 4B, Tables 440, 450, and 460 corresponding to each of the battery types are shown. In each of such tables 440, 450, and 460, the correspondence between the charging current and the threshold voltage for the battery of the type is recorded.

The battery charging device 110 selects one of various tables 440, 450, and 460 in consideration of the type of battery 120, and performs the battery charging method of FIG. 2 in the selected table. For example, the battery charging device 110 selects the table corresponding to the type of battery 120 in tables 440, 450, and 460. The battery charging device 110 selects Table 440 if the type of the battery 120 is a, selects Table 450 if the type of the battery 120 is b, and selects Table 460 if the type of the battery 120 is c. .. The battery charging device 110 can perform the battery charging method of FIG. 2 in the selected table.

In order for the battery charging device 110 according to the embodiment to perform the battery charging method described with reference to FIGS. 1 to 4B, the threshold voltage corresponding to each charging current in the step charging mode must be determined in advance. Hereinafter, how the threshold voltage is determined will be described with reference to FIGS. 5 to 10.

5 to 8B are flowcharts and diagrams for explaining the threshold voltage determination method according to the embodiment.

The threshold voltage determining method according to an embodiment is executed by a threshold voltage determining device.

Referring to FIG. 5, the threshold voltage determining device charges the reference battery in the basic charging mode (S510). The basic charging mode may be CCCV (C-rate = 0.3) as an example. In this case, the threshold voltage determining device charges the reference battery with a constant current of 0.3 C-rate, and charges the reference battery with a constant voltage when the SOC of the reference battery reaches a predetermined SOC (for example, about 80%). do.

The reference battery is a battery of the same type as the battery 120 with a reference electrode inserted therein.

The threshold voltage determining device measures the negative electrode potential of the reference battery being charged in the basic charging mode (S515). Here, the negative electrode potential indicates the difference between the negative electrode potential of the reference battery and the potential of the reference electrode. The threshold voltage determining device measures the negative electrode potential until the reference battery is fully charged.

The threshold voltage determining device searches for the minimum value of the negative electrode potential of the reference battery based on the measurement result of the negative electrode potential (S520), and determines the reference value based on the minimum value (S525). For example, the threshold voltage determining device searches for the minimum value 0.1V of the negative electrode potential from the measurement result 610 of the negative electrode potential shown in FIG. 6, and determines the minimum value as a reference value. In the case of the example shown in FIG. 6, the reference value is 0.1.

The above-mentioned minimum value is an exemplary matter and varies depending on the charging environment. For example, when C-rate = 0.3 in the basic charging mode and the temperature of the negative electrode is lower than normal temperature (for example, when it is −10 ° C.), the minimum value of the negative electrode potential may be 0.075V. When the C-rate of the basic charge mode is smaller than 0.3 and the temperature of the negative electrode is higher than normal temperature (for example, when it is 60 ° C.), the minimum value of the negative electrode potential may be 0.73 V. In the same situation where the temperature of the negative electrode is the same, the minimum value of the negative electrode potential decreases as the C-rate in the basic charge mode increases. The minimum value of the negative electrode potential is set to 0.075V to 0.73V in consideration of the temperature of the negative electrode and the C-rate of the basic charge mode. The minimum value of the negative electrode potential is set to 0.075V to 0.2V in consideration of the negative electrode temperature at room temperature and the C-rate larger than 0.3. Further, the minimum value of the negative electrode potential may differ depending on the type of the reference battery. For example, the active material, the thickness of the electrode, the pore ratio of the electrode, the electrolyte, the current collector, the size of the reference battery, and / or the maximum of the reference battery. Since the voltage differs depending on the type of the reference battery and the above-mentioned items relate to the minimum value of the negative electrode potential, the minimum value of the negative electrode potential may differ depending on the type of the reference battery.

The threshold voltage determining device discharges the reference battery when the reference value is determined (S530). Here, the threshold voltage determining device completely discharges the reference battery.

The threshold voltage determining device charges the discharged reference battery with the charging current in the step charge mode (S535). As an example, the threshold voltage determining device charges with a charging current of 1.2 C-rate in the step charging mode described above.

The threshold voltage determining device compares the voltage of the reference battery being charged with the charging current in the step charging mode with the maximum voltage (S540).

If the voltage of the reference battery is smaller than the maximum voltage, the threshold voltage determining device monitors whether the negative electrode potential of the reference battery reaches the reference value (S545).

As a result of monitoring, if the negative electrode potential of the reference battery does not reach the reference value, the threshold voltage determining device continuously charges the reference battery at 1.2 C-rate.

As a result of monitoring, when the negative electrode potential of the reference battery reaches the reference value, the threshold voltage determining device determines the voltage of the reference battery to the threshold voltage corresponding to the charging current (S550). Further, the threshold voltage determining device changes the charging current (S565). Then, the threshold voltage determining device repeatedly executes steps S535 to S565, and if the voltage of the reference battery is equal to or higher than the maximum voltage, the threshold voltage determining device ends charging (S570).

FIG. 7 shows a graph 710 of the negative electrode potential as a result of repeatedly executing steps S535 to S565. When the negative electrode potential reaches the reference value 720 while the reference battery is charged at 1.2C-rate, it is assumed that the voltage of the reference battery is 3.974V. The threshold voltage determining device determines 3.974V to the threshold voltage corresponding to 1.2C-rate, and changes the charging current to 1.1C-rate. When the negative electrode potential of the reference battery reaches the reference value 720 while the reference battery is being charged at 1.1C-rate, the threshold voltage determining device sets the voltage at which the negative electrode potential reaches the reference value 720 to 1.1C-rate. Determine the corresponding threshold voltage and change the charging current from 1.1C-rate to 1.0C-rate. In such a method, the threshold voltage determining device repeatedly repeats steps S535 to S565 to determine the threshold voltage corresponding to each of the charging currents in the step charging mode, and the correspondence between the charging current and the threshold voltage is established. Complete the recorded table. The completed table corresponds to, for example, Table 2 described above.

By implementation, reference electrodes are inserted into various types of batteries. In this case, the threshold voltage determining device can generate a table corresponding to each battery type by performing the threshold voltage determining method shown in FIG. 5 on the battery into which the reference electrode is inserted. The tables thus generated correspond to Tables 440, 450, and 460 described with reference to FIG. 4B.

According to one embodiment, in step S525, the threshold voltage determining device adds a constant value α to the minimum value to determine a reference value. Here, α is a constant 0 <α ≦ 0.1. In this case, the threshold voltage corresponding to the charging current is determined to be lower than when the reference value is the minimum value, which will be specifically described with reference to FIGS. 8A to 8B.

Referring to FIG. 8A, a graph is shown in the negative electrode potential by the repeated execution results of steps S535 to S565 in each of 810 when the reference value = 0.1 and 820 when the reference value = 0.11. The numerical table for each graph shown in FIG. 8A is shown in Table 3 below.

上記の表３を参照するとき、同じ充電電流であれば、負極電位が基準値＝０．１１に達した時のＳＯＣが基準値＝０．１に達した時のＳＯＣよりも小さい。これは、同じ充電電流が基準バッテリに流れれば、負極電位が基準値＝０．１１に達した時の基準バッテリの電圧は負極電位が基準値＝０．１に達した時の基準バッテリの電圧よりも小さいことを意味する。閾値電圧は、基準値に達した時の基準バッテリの電圧に決定されるため、基準値＝０．１である場合８１０より、基準値＝０．１１である場合８２０に閾値電圧が低く決定される。図８Ｂにおいて基準値＝０．１である場合８１０の閾値電圧（「□」で表示）と基準値＝０．１１である場合８２０の閾値電圧（記号「○」で表示）が示されているが、基準値＝０．１１である場合８２０の閾値電圧が低く形成される。

When referring to Table 3 above, if the charging current is the same, the SOC when the negative electrode potential reaches the reference value = 0.11 is smaller than the SOC when the reference value = 0.1. This is because if the same charging current flows through the reference battery, the voltage of the reference battery when the negative electrode potential reaches the reference value = 0.11 is the voltage of the reference battery when the negative electrode potential reaches the reference value = 0.1. It means that it is smaller than the voltage. Since the threshold voltage is determined by the voltage of the reference battery when the reference value is reached, the threshold voltage is determined to be lower than 810 when the reference value = 0.1 and 820 when the reference value = 0.11. To. In FIG. 8B, the threshold voltage of 810 (indicated by “□”) when the reference value = 0.1 and the threshold voltage of 820 (indicated by the symbol “◯”) when the reference value = 0.11 are shown. However, when the reference value = 0.11, the threshold voltage of 820 is formed low.

When the reference value = 0.11 by the threshold voltage generated in 820, if the battery charging method shown in FIG. 2 is executed, the charging current is changed when the voltage of the battery 120 reaches a low threshold voltage. Therefore, the voltage of the battery 120 is controlled to be low, and the usage period of the battery 120 is further increased. When Table 2 described above is the reference value = 0.1, if the threshold voltage is generated in 810, the battery charging device 110 sets Table 2 to the reference value = 0 in order to further increase the usage period of the battery 120. In the case of .11, the battery charging method shown in FIG. 2 can be performed in place of the threshold voltage generated in 820.

9 and 10 are flowcharts and diagrams for explaining another example of the threshold voltage determination method according to the embodiment.

Referring to FIG. 9, the threshold voltage determining device discharges the reference battery in step S540 when the battery voltage reaches the maximum voltage (S910). Here, the reference battery is completely discharged.

The threshold voltage determining device checks whether the number of charge / discharge cycles of the discharged reference battery corresponds to a predetermined number of times (for example, the predetermined number of times belongs to 2 to 100) (S920). The threshold voltage determining device performs step S920 to confirm whether the reference battery has deteriorated to a predetermined level. If the number of charge / discharge cycles does not correspond to the predetermined number of charge / discharge cycles in step S920, the threshold voltage determination device repeats steps S535 to S565 and steps S910 to S920. In other words, in order to deteriorate the reference battery to a predetermined level, the threshold voltage determining device repeats steps S535 to S565 and steps S910 to S920. The results of the iterative execution of steps S535 to S565 and steps S910 to S920 are shown in FIG. More specifically, FIG. 10 shows a graph for the charge current-threshold voltage for each charge / discharge cycle such as the 5th, 6th, and 10th. The threshold voltage is determined to be lower as the number of charge / discharge cycles increases, but as described above, if the charging of the battery 120 is controlled by the lower determined threshold voltage, the usage period of the battery 120 is further increased. ..

When the number of charge / discharge cycles corresponds to the predetermined number of charge / discharge cycles in step S920, the threshold voltage determination device ends charging. For example, if the number of charge / discharge cycles is 76, the threshold voltage determination device ends charging and generates a charge current-threshold voltage table for the 76th charge / discharge cycle. The generated table is stored in the battery charging device 110.

Depending on the implementation, the threshold voltage determining device generates and stores a charge current-threshold voltage table for each fixed number of charge / discharge cycles. In other words, the threshold voltage determinant produces a table corresponding to the SOH that decreases as the number of charge / discharge cycles increases. The tables thus generated correspond to Tables 410, 420, and 430 described with reference to FIG. 4A above.

FIG. 11 is a block diagram for explaining the battery charging device according to the embodiment.

Referring to FIG. 11, the battery charging device 110 according to one embodiment includes a controller 1110 and a memory 1120.

The controller 1110 charges the battery 120. As an example, the controller 1110 charges the battery 120 with a charging current in the step charging mode.

If a current change event occurs while charging the battery 120 with the charging current, the controller 1110 subsequently changes the charging current to the charging current.

The memory 1120 stores a table in which the correspondence between the charging current and the threshold voltage is recorded. The stored table stores, for example, Table 1 described with reference to FIG. By implementation, memory 1120 stores Tables 410, 420, and 430 described with reference to FIG. 4A and / or Tables 440, 450, and 460 described with reference to FIG. 4B.

Since the matters described with reference to FIGS. 1 to 10 can be applied to the matters described with reference to FIG. 11, detailed description thereof will be omitted.

FIG. 12 is a block diagram for explaining the threshold voltage determining device according to the embodiment.

Referring to FIG. 12, the threshold voltage determination device 1200 according to an embodiment includes a memory 1210 and a controller 1220.

The controller 1220 charges the reference battery in the step charge mode.

When the negative electrode potential of the reference battery reaches the reference value while charging the reference battery in the step charging mode, the controller 1220 determines the voltage of the reference battery to the threshold voltage corresponding to the charging current and changes the charging current. The controller 1220 performs such an operation every time the negative electrode potential of the reference battery reaches the reference value. Thereby, the controller 1220 can determine the threshold voltage corresponding to each charging current in the step charging mode, and can generate a table recording the correspondence between the charging current and the threshold voltage.

The memory 1210 stores the table generated by the controller 1220.

The table generated by the threshold voltage determination device 1200 is stored in the battery charging device 110 described above or the battery management system described later.

Since the matters described with reference to FIGS. 1 to 11 can be applied to the matters described with reference to FIG. 12, detailed description thereof will be omitted.

FIG. 13 is a diagram for explaining an automobile according to an embodiment.

Referring to FIG. 13, vehicle 1300 includes a battery system 1310. The automobile 1300 is an automobile that uses the battery pack 1311 as a power source. The vehicle 1300 can be, for example, an electric vehicle or a hybrid vehicle.

The battery system 1310 includes a battery pack 1311 and a battery management system (BMS) 1312. The battery charging device 110 described above corresponds to an external charger of an automobile 1300 as an off-board charger. In this case, the battery charging device 110 is connected to the automobile 1300 via a cable to charge the battery pack 1311. Depending on the realization, the battery charger 110 may be included in the vehicle 1300 or BMS 1312 as an on-board charger.

The battery charging device 110 controls charging of the battery pack 1311 so that the negative electrode potential of the battery cell contained in the battery pack 1311 is maintained at a reference value or higher. This improves the life characteristics of the battery pack 1311.

Since the matters described with reference to FIGS. 1 to 12 can be applied to the matters described with reference to FIG. 13, detailed description thereof will be omitted.

FIG. 14 is a diagram for explaining a terminal according to an embodiment.

Referring to FIG. 14, the terminal 1400 is connected to the power supply 1420.

Terminal 1400 and power supply 1420 are shown. The terminal 1400 can be a mobile terminal such as a smartphone, a laptop computer, a tablet PC, or a wearable device. The example for the terminal 1400 is merely an example, and the terminal 1400 is not limited to the above-mentioned example.

According to one embodiment, the battery charging device 110 may be included in the terminal 1400. For example, the battery charging device 110 is mounted on the terminal 1400 in the form of an IC (Integrated Circuit). The terminal 1400 performs the battery charging method described above.

According to another embodiment, the battery charging device 110 may be included in the power supply 1420. Here, the power supply 1420 is connected to the charging port of the terminal 1400 by wire or wirelessly. The power supply 1420 operates according to the battery charging method described above to charge the battery 1410 of the terminal 1400.

Although FIG. 14 illustrates the battery 1410 as being included in the terminal 1400, this is merely an exemplary item of the embodiment. For example, the battery 1410 separated from the terminal 1400 may be connected to the power supply 1420 to be charged.

Since the matters described with reference to FIGS. 1 to 13 can be applied to the matters described with reference to FIG. 14, detailed description thereof will be omitted.

Since the negative electrode potential of the battery 120 corresponds to the internal state of the battery 120, it is difficult to measure while the battery 120 is being charged. Therefore, the negative electrode potential of the battery 120 is not measured and estimated during charging, and an electrochemical model can be used for such estimation. However, electrochemical models require high performance, and low-performance battery management systems and mobile terminals are difficult to drive electrochemical models. According to one embodiment, the low performance battery management system and / or mobile terminal performs the battery charging method described above instead of the method of estimating the negative electrode potential using an electrochemical model. Therefore, the low-performance battery management system and / or the mobile terminal can maintain the negative electrode potential of the battery 120 above a certain level while charging the battery 120, and can further improve the life characteristics of the battery 120.

The method according to the embodiment is embodied in the form of program instructions implemented via various computer means and recorded on a computer-readable recording medium. The recording medium includes program instructions, data files, data structures, etc. alone or in combination. The recording medium and program instructions may be specially designed and configured for the purposes of the present invention, and may be known and usable by those skilled in the art of computer software. good. Examples of computer-readable recording media include hard disks, magnetic media such as floppy (registered trademark) disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magnetic-optical such as floptic discs. Includes media and hardware devices specially configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language code as generated by a compiler, but also high-level language code executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the operation of the present invention and vice versa.

Even if the embodiments are described with limited drawings as described above, any person having ordinary knowledge in the art can apply various technical modifications and modifications based on the above. .. For example, the techniques described may be performed in a different order than the methods described, and / or components such as the described systems, structures, devices, circuits, etc. may be combined or combined differently from the methods described. Appropriate results can be achieved when combined or replaced or replaced by other components or equivalents.

Therefore, other embodiment, other embodiments, and those equivalent to the claims also belong to the scope of claims described later.

110 Battery charging device 120 Battery 1200 Threshold voltage determining device 1300 Automobile

Claims (25)

The step of charging the battery with the charging current and
If a current change event occurs during the charging of the battery, the step of changing the charging current and
Including
The current change event occurs when the battery reaches the threshold voltage of the battery.
The threshold voltage indicates a voltage when the negative electrode potential of the battery reaches a reference value, and is set so that the negative electrode potential maintains the reference value or more while charging the battery .
The reference value corresponds to the minimum value among the measurement results of the negative electrode potential of the reference battery of the same type as the battery.
Battery charging method. Further comprising the step of confirming the threshold voltage corresponding to the charging current with reference to the table in which the threshold voltage and the charging current are stored.
The battery charging method according to claim 1. Further comprising the step of substituting the table for the table corresponding to the changed life information when the battery life information changes.
The battery charging method according to claim 2. When the current change event occurs, the step of ending the charging section corresponding to the charging current and
After that, in the charging section, the step of charging the battery with a current lower than the charging current, and
The battery charging method according to any one of claims 1 to 3, further comprising. When the battery reaches the maximum voltage, the step of charging the battery with a constant voltage and
If the charging current is reduced to the end current while the battery is being charged at the constant voltage, the step of ending the charging of the battery and
The battery charging method according to claim 1, further comprising. The battery charging method according to any one of claims 1 to 5, wherein the reference value is 0.075V to 0.73V. The battery charging method according to claim 6, wherein the reference value is 0.075V to 0.2V. A computer program stored in a medium for performing the method according to any one of claims 1 to 7 in combination with hardware. It comprises a controller that charges a battery with a charging current and changes the charging current if a current change event occurs during the charging of the battery.
The current change event occurs when the battery reaches the threshold voltage of the battery.
The threshold voltage indicates a voltage when the negative electrode potential of the battery reaches a reference value, and is set so that the negative electrode potential maintains the reference value or more while charging the battery .
The reference value corresponds to the minimum value among the measurement results of the negative electrode potential of the reference battery of the same type as the battery.
Battery charger. The controller confirms the threshold voltage corresponding to the charging current by referring to a table in which the threshold voltage and the charging current are stored.
The battery charging device according to claim 9. The controller replaces the table with a table corresponding to the changed life information when the battery life information changes.
The battery charging device according to claim 10. The controller ends the charging section corresponding to the charging current when the current change event occurs, and subsequently charges the battery with a current lower than the charging current in the charging section.
The battery charging device according to any one of claims 9 to 11. The controller charges the battery at a constant voltage when the battery reaches the maximum voltage, and terminates charging of the battery when the charging current decreases to the termination current while charging the battery at the constant voltage. ,
The battery charging device according to claim 9. The reference value is 0.075V to 0.73V.
The battery charging device according to any one of claims 9 to 13. The reference value is 0.075V to 0.2V.
The battery charging device according to claim 14. The step of charging the battery with the first charge current value,
When the battery reaches the threshold voltage, the step of charging with a second charge current value lower than the first charge current value, and
Including
The threshold voltage indicates a voltage when the negative electrode potential of the battery reaches a reference value, and is set so that the negative electrode potential maintains the reference value or more while charging the battery .
The reference value corresponds to the minimum value among the measurement results of the negative electrode potential of the reference battery of the same type as the battery.
Battery charging method. The reference value is 0.075V to 0.73V.
The battery charging method according to claim 16. The reference value is 0.075V to 0.2V.
The battery charging method according to claim 17. The first charge current value is 1.0 C-rate or more.
The battery charging method according to any one of claims 16 to 18. Further including a step of confirming the threshold voltage corresponding to the first charging current value with reference to the table in which the first charging current value and the threshold voltage are stored.
The battery charging method according to any one of claims 16 to 19. Further including a step of substituting the table for the table corresponding to the changed life information when the battery life information changes.
The battery charging method according to claim 20. When the battery reaches the maximum voltage, the step of charging the battery with a constant voltage and
If the charging current is reduced to the end current while the battery is being charged at the constant voltage, the step of ending the charging of the battery and
16. The battery charging method according to claim 16. With the battery
When the battery is charged with the initial charging current in the first charging mode and the battery reaches the threshold voltage corresponding to the initial charging current, the initial charging current is changed to the charging current among the charging currents in the first charging mode. The controller to change and
Including
The threshold voltage indicates a voltage when the negative electrode potential of the battery reaches a reference value, and is set so that the negative electrode potential maintains the reference value or more while charging the battery .
The reference value corresponds to the minimum value among the measurement results of the negative electrode potential of the reference battery of the same type as the battery.
Battery system. When the voltage of the battery reaches the maximum voltage, the controller ends charging in the first charging mode and charges the battery to a constant voltage in the second charging mode.
The battery system according to claim 23. The controller ends charging in the second charging mode when the charging current in the second charging mode is reduced to the end current.
The battery system according to claim 24.

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