CN114966445A - Method for inspecting internal resistance of secondary battery and method for manufacturing secondary battery - Google Patents

Method for inspecting internal resistance of secondary battery and method for manufacturing secondary battery Download PDF

Info

Publication number
CN114966445A
CN114966445A CN202210156124.3A CN202210156124A CN114966445A CN 114966445 A CN114966445 A CN 114966445A CN 202210156124 A CN202210156124 A CN 202210156124A CN 114966445 A CN114966445 A CN 114966445A
Authority
CN
China
Prior art keywords
internal resistance
secondary battery
time
value
charging
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210156124.3A
Other languages
Chinese (zh)
Inventor
室田洋辅
石野直
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Primearth EV Energy Co Ltd
Original Assignee
Primearth EV Energy Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Primearth EV Energy Co Ltd filed Critical Primearth EV Energy Co Ltd
Publication of CN114966445A publication Critical patent/CN114966445A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/389—Measuring internal impedance, internal conductance or related variables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/24—Alkaline accumulators
    • H01M10/28—Construction or manufacture
    • H01M10/281—Large cells or batteries with stacks of plate-like electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/24—Alkaline accumulators
    • H01M10/30—Nickel accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Secondary Cells (AREA)
  • Tests Of Electric Status Of Batteries (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

The present invention relates to a method for inspecting internal resistance of a secondary battery, which comprises the following steps: a pre-charging step of charging the secondary battery to a set SOC; a discharge measurement step of discharging the secondary battery for a time (t) or more set so as to eliminate polarization, respond to the component resistance and the reaction resistance, using the set discharge rate after the precharge; a charge measurement step of using the set dischargeCharging the secondary battery at a charging rate of the same current value as the charging rate for the set time (t) or longer; and an internal resistance calculation step of calculating a first voltage value (V) based on the time when the set time (t) has elapsed in the discharge measurement step 1 ) And a first current value (I) 1 ) And a second voltage value (V) at the time when the time (t) has elapsed in the charging measurement step 2 ) And a second current value (I) 2 ) The difference calculates the internal resistance of the secondary battery.

Description

Method for inspecting internal resistance of secondary battery and method for manufacturing secondary battery
Technical Field
The present invention relates to a method for inspecting internal resistance of a secondary battery and a method for manufacturing a secondary battery, and more particularly, to a method for inspecting internal resistance of a secondary battery and a method for manufacturing a secondary battery, which can accurately obtain internal resistance of a secondary battery in a shorter time.
Background
In order to appropriately charge a secondary battery mounted on a vehicle, for example, it is necessary to control the voltage and current, and therefore, it is necessary to measure the internal resistance of the secondary battery. In order to measure the internal resistance with high accuracy, it is necessary to eliminate polarization (an apparent voltage change caused by current application). This polarization is eliminated with the passage of time, and the Voltage converges to OCV (Open Circuit Voltage).
FIG. 9 is a graph showing a time t [ s ] indicating the elimination of the conventional polarization]And a voltage V [ V ]]A graph of the relationship of (1). In the prior art, in order to eliminate polarization, as shown in FIG. 9, the battery is charged to SOC (State Of Charge) for internal resistance check, and at the end time t Of the charging 0 Then, the operation is stopped for a certain stop time t R After a time t P1 、t P2 Pulse application P was performed at 10A and 60A 1 、P 2 The internal resistance is determined.
In this conventional method, the rest time t is required R The internal resistance check requires a long time.
Fig. 10 is a diagram showing a relationship among time t [ s ], voltage V [ V ], and current I [ a ] in the internal resistance detection step described in patent document 1. In the invention described in patent document 1, the time for the internal resistance inspection is shortened by performing the internal resistance detection step in the step shown in fig. 10. In this step, the battery is charged at an internal resistance detection voltage (EV2) equal to or lower than the final charge voltage (EVT), and the internal resistance is detected. In this step, the battery is pulse-charged at a constant voltage and a constant current, and the internal resistance is detected from the difference between the battery voltage at the time of charging and the battery voltage at the time of rest charging. The internal resistance value R of the battery 1 is calculated from (E1-E0)/I. In the formula, E1 is a battery voltage when charging is performed with a current I, E0 is a battery voltage when charging is suspended, and I is a charging current.
In such an internal resistance detection step, the internal resistance can be obtained in a short time.
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 2002-142379
Disclosure of Invention
Problems to be solved by the invention
However, in the invention described in patent document 1, although the internal resistance can be obtained in a short time, the influence of polarization is still large in pulse charging during charging, and it is not necessarily said that accurate measurement of the internal resistance without being affected by polarization is possible.
The invention provides a method for inspecting internal resistance of a secondary battery and a method for manufacturing the secondary battery, which aims to obtain the internal resistance of the secondary battery with high precision in a shorter time.
Means for solving the problems
In order to solve the above problem, an internal resistance inspection method according to the present invention is a method for inspecting an internal resistance of a secondary battery for measuring an internal resistance of the secondary battery to be measured, the method including the steps of: a pre-charging step of charging the secondary battery to a set SOC; a discharge measurement step of discharging the secondary battery for a predetermined time t or more at a set discharge rate after the precharge step is completed; a charge measurement step of charging the secondary battery at a charge rate having the same current value as the set discharge rate for the predetermined time t or longer after the discharge measurement step is completed; and an internal resistance calculation step of calculating an internal resistance based on the first voltage value V at the time when the predetermined time t has elapsed in the discharge measurement step 1 And a first current value I 1 And a second voltage value V at the time when the predetermined time t has elapsed in the charge measurement step 2 And a second current value I 2 Calculating the above-mentioned second order from the differenceThe internal resistance of the battery.
In the internal resistance inspection method, the predetermined time t may be set in the discharge measurement step so as to cancel polarization, and to respond to a component resistance or a reaction resistance.
The internal resistance inspection method may further include a reference resistance value obtaining step of obtaining a reference resistance value of the secondary battery to be measured, prior to the internal resistance inspection method for the secondary battery; the method further includes a calibration step of determining the preset time t used in common in the discharge measurement step and the charge measurement step, based on the reference resistance value.
In the internal resistance inspection method, the reference resistance value obtaining step may include the steps of: a polarization elimination step of suspending application of current until influence of polarization does not affect measurement; and an internal resistance obtaining step of applying a current value I set to P A pulse current for charging is simultaneously applied at the same current value I as the pulse current P Pulse current for performing discharge to obtain voltage values V of the charge and the discharge respectively P Sum current value I P In the internal resistance obtaining step, the set current value I is changed P The application of the pulse current is repeated a plurality of times, and the voltage value V obtained based on these is P Sum current value I P The reference resistance value is obtained.
In the internal resistance inspection method, the precharge is performed until the voltage reaches a flat region, which is an SOC region where the voltage is stable with respect to the capacity.
The internal resistance inspection method can be suitably performed when the secondary battery is a nickel-metal hydride storage battery.
In addition, the manufacturing method of the secondary battery may include an internal resistance inspection method of such a secondary battery.
ADVANTAGEOUS EFFECTS OF INVENTION
The internal resistance of the secondary battery can be accurately obtained in a short time by the method for inspecting the internal resistance of the secondary battery and the method for manufacturing the secondary battery according to the present invention.
Drawings
Fig. 1 is a perspective view showing the structure of the nickel-metal hydride storage battery of the present embodiment.
Fig. 2 is a sectional view of a stack of battery cells provided in the nickel-metal hydride storage battery of the present embodiment.
Fig. 3 is a schematic diagram showing a partial configuration of an example of a manufacturing apparatus of a nickel-metal hydride storage battery as an internal resistance inspection apparatus.
Fig. 4 is a time chart showing the internal resistance inspection method of the present embodiment in time series.
Fig. 5 is a flowchart showing the steps of the internal resistance checking method.
Fig. 6 is a scatter diagram for obtaining the reference resistance value.
Fig. 7 is a graph comparing the internal resistance of the nickel-metal hydride storage battery measured with respect to the reference resistance value Rs Ω and the change time t s.
Fig. 8 is a timing chart showing a part of the internal resistance test in the present embodiment shown in fig. 4.
Fig. 9 is a graph showing a relationship between time t [ s ] and voltage V, which indicates conventional elimination of polarization.
Fig. 10 is a diagram showing a relationship among time t [ s ], voltage V [ V ], and current I in the internal resistance detection step described in patent document 1.
Detailed Description
The method for inspecting the internal resistance of a secondary battery and the method for manufacturing a secondary battery according to the present invention will be described below with reference to fig. 1 to 8 as one embodiment of a method for inspecting the internal resistance of a nickel-metal hydride storage battery 11 and a method for manufacturing a secondary battery.
(constitution of the present embodiment)
< brief summary of the present embodiment >
Fig. 4 is a time chart showing the internal resistance inspection method of the present embodiment in time series. The internal resistance inspection method of the present embodiment aims to obtain the internal resistance value R of the secondary battery with high accuracy in a shorter time. Specifically, the polarization after charging is performed instead of the conventional polarization shown in fig. 9Rest time t of elimination R In the present embodiment, the polarization caused by the precharge is quickly eliminated by performing the discharge and the charge after the precharge. As shown in fig. 4, immediately after the precharge, the discharge is performed for a period of time t, and the polarization is eliminated in a short time by the reverse current. In addition, immediately thereafter, charging is performed for the same time t, whereby polarization is eliminated in a short time by the reverse current. By setting the charging and discharging time to the same time t, the influence of polarization in measuring the internal resistance is canceled and eliminated, and the time for obtaining the internal resistance of the secondary battery can be shortened.
However, the internal resistance inspection method of the present embodiment has the following features so as not to degrade the acquisition accuracy.
First, the internal resistance value R is obtained in a state of being charged to a flat region, which is an SOC region where the voltage is stable with respect to the capacity, by precharging. This is because it is estimated that the internal resistance may increase if the voltage change accompanying the capacity change is large.
Then, the internal resistance value R is obtained from the difference between the current value and the voltage value at 2 points of the specific time point of the discharging and charging after the precharging. In this case, in the present embodiment, the calibration of the internal resistance measurement method is performed for accurate measurement. Therefore, the reference resistance value R as a calibration reference is accurately obtained by measuring the internal resistance of the target nickel-metal hydride storage battery 11 in advance. The reference resistance value Rs is obtained by actually measuring the characteristics of the nickel-metal hydride storage battery 11 to be measured.
Based on the reference resistance value Rs thus obtained, the length of the common "time t" at which the measurement time points of the discharge time and the charge time are determined in the internal resistance inspection method of the present embodiment is set.
In order to reliably obtain the reference resistance value Rs, the nickel-metal hydride storage battery 11, in which polarization is eliminated to such an extent that the polarization does not affect the measurement, is measured using a rest time sufficient for measuring the reference resistance value Rs. Then, while the voltage V of the nickel-metal hydride storage battery 11 is stable, the current value I is changed, and a plurality of pulses are applied to the nickel-metal hydride storage battery 11. These currents/voltages are plotted and a straight line fitting is performed to obtain the reference resistance value Rs. Further, a plurality of different nickel-metal hydride storage batteries 11 can be measured, and a more reliable reference resistance value Rs can be obtained.
Regarding the time for obtaining the internal resistance value R from the voltage difference of 2 points of discharge and charge, the "time t" for obtaining the internal resistance is set in consideration of the difference in response speed of each resistance component of the internal resistance with respect to the current application. As for the difference in response speed of each resistance component, specifically, the elimination of the response polarization is first performed. I.e. in response to a resistance component due to polarization. As for the elimination of polarization, the elimination can be performed substantially instantaneously when a reverse current is applied. Followed by the response component resistance. And finally to the reaction resistance. Therefore, the accurate internal resistance cannot be measured at a time before the reaction resistance is sufficiently responded. The response of the presence or absence of such a reaction resistance varies depending on the current value of the target secondary battery. That is, the time until the reaction resistance sufficiently responds depends on the target secondary battery and the current value. Therefore, the measurement time for obtaining the internal resistance with high accuracy needs to be determined based on the secondary battery to be actually measured and the current value used for measurement.
< construction of Nickel-Metal hydride storage Battery 11 >
Fig. 1 is a perspective view showing the structure of a nickel-metal hydride storage battery 11 of the present embodiment. Fig. 2 is a sectional view of the stacked body 25 of the battery cells 12 provided in the nickel-metal hydride storage battery 11 of the present embodiment. First, the nickel-metal hydride storage battery 11 of the method for manufacturing the nickel-metal hydride storage battery 11 of the present embodiment will be described.
< Battery Module >
As shown in fig. 1, the nickel-metal hydride storage battery 11 is configured as a battery module including a plurality of battery cells 12. The plurality of battery modules of the present embodiment are bound to each other to constitute a vehicle-mounted battery pack as a structure including electrical components, a cover, and the like. The nickel-metal hydride storage battery 11 is, for example, a sealed battery in the form of a rectangular plate. The nickel-metal hydride storage battery 11 includes an integrated electric tank 13 capable of housing a plurality of (here, 6) battery cells 12, and a lid 14 for sealing an opening of the integrated electric tank 13. The integrated electric tank 13 and the lid 14 are formed of, for example, a resin material. A plurality of (here, 6) battery cells 12 electrically connected in series are housed in the integrated battery tank 13. The electric power of the battery cells 12 is taken out from the positive electrode terminal 13a and the negative electrode terminal 13b provided in the integrated electric tank 13.
< Battery cell 12>
As shown in fig. 2, the battery cell 12 includes: a laminate 25 composed of the electrode group 20 and the current collecting plates 21,22, and an electrolyte not shown in the drawing stored in the integrated electric tank 13 together with the laminate 25. The electrode group 20 is formed by stacking plate-shaped positive electrode plates 15 and negative electrode plates 16 with separators 17 interposed therebetween. End 15a of positive electrode plate 15 is bonded to the bonding surface of positive current collector plate 21. The end 16a of the negative electrode plate 16 is bonded to the bonding surface of the negative current collector plate 22.
< negative electrode plate 16>
The negative electrode plate 16 will be described next. The negative electrode plate 16 includes a core material and a hydrogen storage alloy supported on the core material. The type of the hydrogen-absorbing alloy is not particularly limited, and examples thereof include an alloy of nickel and a misch metal which is a mixture of rare earth elements, and an alloy in which a part of the alloy is substituted with a metal such as aluminum, cobalt, or manganese. The negative electrode plate 16 is produced as follows: the negative electrode plate is produced by adding a thickener such as carbon black and a binder such as a styrene-butadiene copolymer to a hydrogen storage alloy, filling the hydrogen storage alloy processed into a paste into a core material such as a punching metal, and then drying, rolling and cutting the filled core material.
< electrolyte solution >
The electrolyte solution will be described next. The electrolyte is held by the separator 17, and ion conduction is performed between the positive electrode plate 15 and the negative electrode plate 16.
The electrolyte is an alkaline aqueous solution containing potassium hydroxide (KOH) as a main component of the solute.
< Positive electrode plate 15>
The positive electrode plate 15 will be described next. The positive electrode plate 15 has a base material made of a three-dimensional porous body made of nickel, and a positive electrode composite material supported on the base material. The base material has a function of a carrier supporting the filler and a function of the current collector. The paste as the positive electrode composite material contains positive electrode active material particles containing nickel hydroxide as a main component, cobalt (Co) as a metal functioning as a conductive material, a thickener, a binder, and the like. In the present embodiment, metallic cobalt (Co) is exemplified, but cobalt oxide represented by cobalt monoxide (CoO), a cobalt compound, or the like may be contained.
< apparatus 30 for producing Nickel-Metal hydride storage Battery >
Fig. 3 is a schematic diagram showing a partial configuration of a manufacturing apparatus 30 of a nickel-metal hydride storage battery 11 as an example of an internal resistance inspection apparatus for a secondary battery. The functions of the manufacturing apparatus 30 of the nickel-metal hydride storage battery 11 include the functions of the internal resistance inspection apparatus shown in fig. 3. The manufacturing apparatus 30 constituting the internal resistance inspection apparatus includes a charging/discharging device 32 capable of charging/discharging the nickel-metal hydride storage battery 11, and a control device 31 for controlling the charging/discharging device 32. The control device 31 includes a computer and controls the charging/discharging device 32 by a control signal. The charge/discharge device 32 charges or discharges the nickel-metal hydride storage battery 11 based on the signal control from the control device 31. The control device 31 performs control of charging and discharging the nickel-metal hydride storage battery 11 at a specific voltage or current based on the stored program. The control is performed based on the measurement results obtained by the voltmeter 34 that measures the voltage of the cell module of the nickel-metal hydride storage battery 11 and the ammeter 33 that measures the current flowing through the nickel-metal hydride storage battery 11. The nickel-metal hydride storage battery 11 is charged and discharged by using the function of the manufacturing apparatus 30.
(operation of the present embodiment)
< method for producing Nickel-Metal hydride storage Battery 11 >
Next, a method for manufacturing the nickel-metal hydride storage battery 11 will be described. The method for manufacturing the nickel-metal hydride storage battery 11 includes a positive electrode manufacturing step, a negative electrode manufacturing step, an assembling step, an activating step, and an inspecting step.
< Positive electrode production step >
In the positive electrode production step, a paste is prepared by adding a specific amount of cobalt, a thickener, and the like to the positive electrode active material particles having the coating layer, and kneading the mixture. And then filled into a substrate comprising a three-dimensional porous body made of nickel obtained by foaming the paste. After drying, the base material is press-molded and cut into a predetermined size, thereby producing the positive electrode plate 15.
< negative electrode production step >
In the negative electrode manufacturing step, the hydrogen storage alloy powder is immersed in an alkaline aqueous solution, stirred, washed with water, and dried. Further, a binder or the like is added to the dried hydrogen absorbing alloy powder, and the mixture is kneaded to prepare an active material paste. Then, the active material paste is applied to a core material such as a punching metal, and the core material is dried, rolled, and cut to produce the negative electrode plate 16.
< assembling step >
In the assembly step, the positive electrode plate 15 and the negative electrode plate 16 are laminated with a separator 17 made of an alkali-resistant resin nonwoven fabric or the like interposed therebetween. The end 15a of the positive electrode plate 15 is bonded to the collector plate 21 by welding or the like, and the end 16a of the negative electrode plate 16 is bonded to the collector plate 22 by welding or the like, thereby producing a laminate 25. The laminate 25 is further stored in the integrated electric tank 13 together with an electrolyte solution containing potassium hydroxide as a main component of the solute, and the integrated electric tank 13 is sealed.
< activation step >
The activation step comprises: a Co charging step of activating Co of the positive electrode; a conditioning step for activating, charging and discharging the hydrogen storage alloy of the negative electrode; and an aging step. The nickel-metal hydride storage battery as a product is completed through these steps.
< inspection step >
In the inspection step, an OCV inspection step, an internal resistance inspection step, and the like are performed by a performance test as a product before shipment. In the internal resistance inspection step, the internal resistance inspection method of the present embodiment is performed.
< method of inspecting internal resistance >
Fig. 5 is a flowchart showing the steps of the internal resistance checking method. The steps of the internal resistance inspection method will be described with reference to fig. 5.
< obtaining of reference resistance value Rs (S1) >
Before the internal resistance checking method is started, the reference resistance value Rs is obtained in advance (S1). That is, the reference resistance value obtaining step (S1) of obtaining the reference resistance value of the secondary battery is performed before the precharge step (S5) of charging the secondary battery to the set SOC.
Fig. 6 is a scatter diagram for obtaining the reference resistance value Rs. The horizontal axis of the graph represents a current value IA, and the vertical axis represents a voltage value V. In order to reliably obtain the reference resistance value Rs, the voltage of the nickel-metal hydride storage battery 11, polarization of which is eliminated to such an extent that the polarization does not affect the measurement, is measured using, for example, a sufficient rest time of 30 minutes or more. This step corresponds to the polarization elimination step of the present invention. After that, the current value is changed to apply a pulse current in a state where the voltage is stabilized. The applied current value is, for example, 10 to 50[ A ]. In the present embodiment, the voltage after 4.9 seconds after the current application was measured, and the combination of the current I and the voltage V was obtained for 4 points Pa, Pb, Pc, and Pd for charging with changing current values and for 8 points Pa ', Pb', Pc ', and Pd' for discharging with the same current values as charging. As shown in FIG. 6, Pa, Pb, Pc, Pd, Pa ', Pb', Pc ', and Pd' were plotted. The plotted points are fitted to a straight line by, for example, the least square method or the like. Then, a reference resistance value Rs is obtained from Δ V/Δ I [ A ] ═ Rs [ Ω ]. In one example, a plurality of discharge pulse currents and a plurality of charge pulse currents are applied to the nickel-metal hydride storage battery 11 in a state where the voltage is stable, and a plurality of voltage values of the voltage of the nickel-metal hydride storage battery 11 are measured. In one example, the plurality of discharge pulse currents and the plurality of charge pulse currents may have the same current value. In one example, the voltage of the nickel-metal hydride storage battery 11 may be measured after a certain time has elapsed after the discharge pulse current or the charge pulse current is applied. In one example, the reference resistance value Rs is obtained based on a plurality of measured voltage values and a plurality of corresponding current values. It is further preferable to obtain a more reliable reference resistance value Rs by using a plurality of different nickel-metal hydride storage batteries 11 as measurement targets. This step corresponds to the reference resistance value obtaining step of the present invention.
< measuring the internal resistance value R with the changing time t (S2) >
Fig. 7 is a graph comparing the reference resistance value Rs with the internal resistance value R of the nickel-metal hydride storage battery 11 measured with the change time t [ s ]. Similarly to fig. 6, the abscissa of the graph represents the current value [ a ] and the ordinate represents the voltage value [ V ]. A graph of the reference resistance value Rs shown in fig. 6 is shown therein as a solid line.
Initially, since the value of the appropriate time t is unknown, for example, the time t is set to 90[ s ] and an internal resistance inspection method is attempted to be performed. As a result, the slope of the straight line having t of 90 s in fig. 7 is larger than the slope of the straight line having the reference resistance value Rs, that is, the internal resistance is large. Then, the time t is set to 30 s, and an internal resistance inspection method is attempted. Thus, the slope of the straight line at time t of fig. 7 equal to 30[ s ] is smaller than the slope of the straight line at the reference resistance value Rs, that is, the internal resistance is small. Then, the intermediate time t is set to 60[ s ], and an internal resistance inspection method is attempted to be performed. Thus, the slope of the straight line at time t of 60[ s ] in fig. 7 is the same as the slope of the straight line at the reference resistance value Rs, and the straight lines overlap each other. I.e. equal internal resistance. Therefore, in the present embodiment, when the time t is set to 60[ s ], the internal resistance of the nickel-metal hydride storage battery 11 can be accurately measured by the internal resistance inspection method of the present embodiment. By adjusting the setting of the time t in this way, the accuracy of the internal resistance inspection method of the present embodiment can be improved.
< determination of time t (S3) >
Next, in order to accurately measure the internal resistance of the nickel-metal hydride storage battery 11 by the internal resistance inspection method of the present embodiment, the time t(s) obtained in the above-described step is determined to be t 60 seconds, and is set. As described above, since the time until the reaction resistance sufficiently responds depends on the target secondary battery and the current value, the time t (S) can be set for each target secondary battery and current value by executing S1 to S3. In one example, the time t(s) represents a time until the response of the reaction resistor is completed, for example, a time until the reaction resistor sufficiently responds. The time t(s) may be set according to the target secondary battery and the current value, and is not limited herein.
< initiation of internal resistance inspection (S4) >
The correction process of the internal resistance inspection device of the present embodiment is completed through the above steps, and thus the internal resistance inspection method of the actual product can be implemented.
< precharge (S5) >
First, precharge is performed (S5). During the precharge, the nickel-metal hydride storage battery 11 is charged to a flat region (for example, 20 to 80%) which is an SOC region where the voltage is stable with respect to the capacity. If the hydrogen storage alloy is in a state of coexistence of solid solution and hydride, a region (referred to as flat) in which the amount of dissolved hydrogen increases but the hydrogen pressure does not increase occurs. When all of the hydrogen is converted into hydride, the amount of dissolved hydrogen starts to increase again with an increase in hydrogen pressure, but generally the amount of dissolved hydrogen increases little with an increase in pressure (even if the pressure increases by several MPa, several 10 MPa). The region in which hydrogen is occluded and released using a hydrogen storage alloy is mainly a flat region in which pressure control is easy and the occluded amount significantly changes.
Therefore, in the present embodiment, the internal resistance is obtained in a state of being charged to a flat region, which is an SOC region in which the voltage is stable with respect to the capacity, by the precharge. This is because it is estimated that the internal resistance may increase if the voltage change accompanying the capacity change is large. In the present embodiment, the nickel-metal hydride storage battery 11 is charged to a target SOC, for example, SOC 80%, at an arbitrary value of the charge rate of 3 to 6C.
After the charging to the target SOC (YES in S6), the charging is suspended (S7).
< measurement of discharge (S8) >
Fig. 8 is a timing chart showing a part of the internal resistance test in the present embodiment shown in fig. 4. As a premise, the optimum time t varies depending on the type, lot number, and the like of the battery to be measured. Since the tact time of the flow operation is included in the production steps in the factory, it is not preferable to change t every time from the viewpoint of production efficiency 0 ～t 1 'discharge time, t 1-t 2' charge time. Therefore, the discharge time and the charge time are set by approximately predicting the time including the time t. Wherein the current and voltage are measured accurately at the time t.
At time t 0 After the completion of the precharge (S7), the discharge measurement is started (S8). In the discharge measurement, the nickel-metal hydride storage battery 11 is discharged at a discharge rate of any value of 3 to 6C. From this time t 0 Counting is started and the discharge is continued until at least time t has elapsed. With respect to time t [ s ]]In the present embodiment, 60[ s ]]. At the start of discharge, the polarization is first eliminated. Therefore, in the region a, the voltage sharply drops and reaches the OCV. After the elimination of the polarization, the component resistance is responded to in region B. Therefore, the voltage is slowly decreased. In addition, the voltage drops more slowly in region C in response to the reaction resistance.
Here, the time t [ s ] is measured by the measuring device of the control device 31 while the time is measured]Until t [ s ] is reached]＝60[s]Until then (S9: NO), the discharge is continued. And, at time t [ s ]]＝60[s]Thereafter (S9: YES), the current I at the time when the time t has elapsed is measured and stored 1 And voltage V 1 (S10). Thereafter, the discharge is terminated and the charge is started (S11). In the present embodiment, the discharge is slightly continued after the time t elapses, and the discharge is continued at the time t 1 ' end.
This step corresponds to the discharge measurement step of the present invention. In addition, current I 1 Corresponding to a first current value and a voltage V 1 Corresponding to the first voltage value.
< measurement of Charge (S11) >
Charging measurement (S11) time t from the end of discharge measurement 1 ' start. In the charge measurement, the charge is started by changing the flow of current having the same current value as the discharge rate of the discharge measurement. I.e. at time t 1 ' charging is started at a charging rate of the same current value as the discharging rate of the discharge measurement.
In the charge measurement, from the time t 1 ' measurement is started, and charging is continued until at least time t elapses. Time t [ s ] for measurement]Is 60 s equal to the discharge time]. At the start of charging, the polarization is first eliminated. Therefore, in the region a', the voltage sharply rises and reaches OCV. After the elimination of the polarization, the component resistance is responded to in region B'. Therefore, the voltage rises slowly. In addition, in region C' the response resistance, and thusThe voltage rises more slowly.
Here, the time t [ s ] is measured by the measuring device of the control device 31 while]Until reaching time t s]＝60[s]Until then (S12: NO), the discharge is continued. And, at time t [ s ]]＝60[s]Thereafter (S12: YES), the current I at the time when the time t has elapsed is measured and stored 2 And voltage V 2 (S13). In the present embodiment, the charging is continued slightly after the time t elapses, and the charging is continued at the time t 2 ' end.
This step corresponds to the charge measurement step of the present invention. In addition, current I 2 Corresponding to the second current value, voltage V 2 Corresponding to the second voltage value.
< calculation of internal resistance value R >
According to the current I 1 Voltage V 1 The current I measured in the measurement (S10) 1 Voltage V 1 At a current I 2 Voltage V 2 The current I measured in the measurement (S13) 2 Voltage V 2 The internal resistance value R of the nickel-metal hydride storage battery 11 to be measured is calculated. Here, the mathematical formula "R ═ (V) is used 2 -V 1 )/(I 2 -I 1 ) "calculate the internal resistance value R (S14).
< inspection of internal resistance >
The internal resistance value R thus calculated is compared with the reference resistance value Rs (S15). Here, it is determined whether or not the calculated internal resistance value R falls within the allowable range based on the reference resistance value Rs, and if the calculated internal resistance value R does not fall within the allowable range based on the reference resistance value Rs (no in S15), it is determined that the internal resistance of the nickel-metal hydride storage battery 11 does not meet the product shipment standard, and shipment of the nickel-metal hydride storage battery 11 is stopped (S16). On the other hand, when the calculated internal resistance value R falls within the allowable range based on the reference resistance value Rs (yes in S15), the inspection of the nickel-metal hydride storage battery 11 is judged as being acceptable (S17), and the implementation of the internal resistance inspection method of the present embodiment is terminated (end). Thereafter, the nickel-metal hydride storage battery 11 that has been inspected to be acceptable is determined (S17) to have an internal resistance that meets the shipping criteria of the product, for example, to be stored in a battery pack for mounting on a vehicle, to be stacked, to be mounted with auxiliary equipment, or the like, and is prepared for shipment in the subsequent steps.
(Effect of the present embodiment)
The method for manufacturing a nickel-metal hydride storage battery including the internal resistance inspection method of the present embodiment exhibits the following effects.
(1) In the conventional internal resistance test, it is necessary to stop for about 30 minutes in order to eliminate polarization, but in the present embodiment, polarization is quickly eliminated by charge and discharge, and therefore, the internal resistance of the nickel-metal hydride storage battery can be quickly measured.
(2) In the discharge measurement and the charge measurement for measuring the internal resistance, the current and the voltage are measured at the same time t, and therefore, the influence of the polarization, such as ketone, is canceled out, and the measurement result is not affected by the polarization.
(3) In the internal resistance inspection method according to the present embodiment, not only polarization but also the response time of the component resistance and the reaction resistance are taken into consideration, and therefore, the measurement error due to the influence of these factors can be suppressed.
(4) Further, since the characteristics of the internal resistance of the nickel-metal hydride storage battery 11 to be inspected are measured in detail in advance, the reference resistance value Rs is obtained in advance, and the internal resistance inspection method is corrected based on the reference resistance value Rs, the internal resistance can be accurately inspected by the internal resistance inspection method of the present embodiment even if the secondary battery to be inspected is changed.
(5) Since the correction by the internal resistance inspection method is obtained by changing the current value by a plurality of pulses, an error or the like is not easily generated, and accurate correction can be performed.
(6) In the calibration of the internal resistance inspection method, the internal resistance inspection method of the present embodiment is actually performed by adjusting the length of the time t for measurement, and therefore, precise adjustment can be performed.
(7) In the test, the charging is performed in a state in which the voltage is stable with respect to the capacity in the SOC region, and therefore, it is possible to suppress the occurrence of an error in the internal resistance due to a large voltage change accompanying the capacity change.
(8) In the internal resistance inspection method according to the present embodiment, since the determination can be easily performed based on the voltage and the current, the method can be implemented by a simple apparatus.
(9) With such an internal resistance inspection method, shipment of a product having a problem in internal resistance can be effectively prevented in advance.
(10) By obtaining the accurate reference resistance value Rs for each product, it is possible to perform the inspection suitable for the battery.
(other examples of the present embodiment mode)
The present invention has been described above with reference to the embodiments, but the present invention is not limited to the embodiments and can be carried out as follows.
The reference resistance value Rs is obtained by a method not limited to the method of the embodiment but may be obtained by another method depending on the secondary battery to be inspected.
The flowchart shown in fig. 5 is an embodiment of the present invention, and those skilled in the art can add, delete, change the order of the steps, and change the steps.
In the present embodiment, the battery module of the nickel-metal hydride storage battery 11 for vehicle use has been described as an example, but the application is not limited thereto, and the present invention can be applied not only to ships and aircrafts but also to a case where the state of the battery for ground mounting is determined. The inspection target is not limited to the battery module, and individual cells or the like may be used.
The battery module of the secondary battery has been described by taking the nickel-metal hydride storage battery 11 as an example, but may be a lithium-ion secondary battery or the like, and the type of the battery is not limited.
The embodiments described in the embodiments and the modifications may be implemented by being interchanged with each other as long as they are not contradictory.
The present embodiment is an example of the present invention, and those skilled in the art can implement the present invention by adding, deleting, or modifying the configuration without departing from the claims.

Claims (7)

1. A method for inspecting internal resistance of a secondary battery, which measures internal resistance of the secondary battery to be measured, the method comprising:
a pre-charging step of charging the secondary battery to a set SOC;
a discharge measurement step of discharging the secondary battery for a predetermined time (t) or longer at a predetermined discharge rate after the precharge step is completed;
a charge measurement step of charging the secondary battery for the predetermined time (t) or longer at a charge rate having the same current value as the set discharge rate after the discharge measurement step is completed; and
an internal resistance calculation step of calculating an internal resistance based on a first voltage value (V) at the time when the predetermined time (t) has elapsed in the discharge measurement step 1 ) And a first current value (I) 1 ) And a second voltage value (V) at the time when the preset time (t) has elapsed in the charging measurement step 2 ) And a second current value (I) 2 ) The difference calculates the internal resistance of the secondary battery.
2. The method for inspecting internal resistance of a secondary battery according to claim 1,
in the discharge measurement step, the predetermined time (t) is set so that elimination of polarization, response of a component resistance and a reaction resistance are performed.
3. The method of inspecting internal resistance of a secondary battery according to claim 1 or 2,
a reference resistance value obtaining step of obtaining a reference resistance value of the secondary battery as the measurement object before the internal resistance inspection method of the secondary battery;
the method further includes a calibration step of determining the preset time (t) used in common in the discharge measurement step and the charge measurement step, based on the reference resistance value.
4. The method of inspecting internal resistance of a secondary battery according to claim 3,
the reference resistance value obtaining step includes the steps of:
a polarization elimination step of suspending application of current until influence of polarization does not affect measurement; and
an internal resistance obtaining step of applying a set current value (I) P ) Pulse current for charging is simultaneously applied at the same current value (I) as the pulse current P ) A pulse current for performing a discharge, voltage values (V) for said charging and said discharging being obtained respectively P ) Sum current value (I) P )，
In the internal resistance obtaining step, the set current value (I) is changed P ) Repeatedly applying the pulse current for a plurality of times, and obtaining a voltage value (V) based on the pulse current P ) Sum current value (I) P ) And obtaining the reference resistance value.
5. The method of inspecting internal resistance of a secondary battery according to claim 1 or 2,
in the precharge step, the battery is charged to an SOC region where the voltage is stable with respect to the capacity, that is, a flat region.
6. The method of inspecting internal resistance of a secondary battery according to claim 1 or 2,
the secondary battery is a nickel-metal hydride storage battery.
7. A method for manufacturing a secondary battery, characterized by comprising the method for inspecting internal resistance of a secondary battery according to any one of claims 1 to 6.
CN202210156124.3A 2021-02-26 2022-02-21 Method for inspecting internal resistance of secondary battery and method for manufacturing secondary battery Pending CN114966445A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021031063A JP7260576B2 (en) 2021-02-26 2021-02-26 SECONDARY BATTERY INTERNAL RESISTANCE INSPECTION METHOD AND SECONDARY BATTERY MANUFACTURING METHOD
JP2021-031063 2021-02-26

Publications (1)

Publication Number Publication Date
CN114966445A true CN114966445A (en) 2022-08-30

Family

ID=82976535

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210156124.3A Pending CN114966445A (en) 2021-02-26 2022-02-21 Method for inspecting internal resistance of secondary battery and method for manufacturing secondary battery

Country Status (2)

Country Link
JP (1) JP7260576B2 (en)
CN (1) CN114966445A (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000021455A (en) * 1998-07-03 2000-01-21 Nissan Motor Co Ltd Method for detecting internal resistance of battery for hybrid vehicle
JP2002142379A (en) * 2000-11-06 2002-05-17 Sanyo Electric Co Ltd Charging method for battery
CN108291944B (en) * 2016-01-29 2021-03-23 日本汽车能源株式会社 Battery management device
JP6740844B2 (en) * 2016-10-05 2020-08-19 株式会社デンソー Battery resistance calculator
JP7003751B2 (en) * 2018-03-12 2022-01-21 トヨタ自動車株式会社 Battery diagnostic device and battery diagnostic method

Also Published As

Publication number Publication date
JP2022131874A (en) 2022-09-07
JP7260576B2 (en) 2023-04-18

Similar Documents

Publication Publication Date Title
JP5464119B2 (en) Method for producing lithium ion secondary battery
KR101951067B1 (en) Secondary battery control device and soc detection method
EP2764378B1 (en) Apparatus and method for accurate energy device state-of-health (soh) monitoring
JP2014222603A (en) Inspection method for battery
JP5585718B2 (en) Secondary battery inspection method
JP5464118B2 (en) Method for producing lithium ion secondary battery
CN110850306B (en) Inspection method and manufacturing method for electricity storage device
JP6742937B2 (en) Secondary battery state determination method and secondary battery state determination device
JP2009252459A (en) Alkali storage battery inspecting method
JP4529364B2 (en) Cylindrical battery inspection method
JP5464117B2 (en) Method for producing lithium ion secondary battery
JP4048905B2 (en) Battery inspection method
JP2015122169A (en) Method of inspecting all-solid battery
EP3783378A1 (en) Jig pressing-type pressing short-circuiting inspection method
JP6834416B2 (en) Battery system
KR101471775B1 (en) Method of inspecting for lithium ion secondary battery
JP5861189B2 (en) Secondary battery inspection method
CN114966445A (en) Method for inspecting internal resistance of secondary battery and method for manufacturing secondary battery
JP2005251538A (en) Inspection method and device of secondary cell
JP2020198187A (en) Secondary battery manufacturing method, and nickel hydrogen secondary battery
CN115986057A (en) Method for reducing polarization effect of three-electrode battery detection
KR20220138739A (en) Method for detecting abnormal battery through relative comparison
KR20220118250A (en) Device and method for detecting damage to monocell type separator
JP6834415B2 (en) Battery system
JP7222308B2 (en) Inspection method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination