CN113552494A - Low-temperature step charging method and testing method for lithium ion battery - Google Patents
Low-temperature step charging method and testing method for lithium ion battery Download PDFInfo
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- CN113552494A CN113552494A CN202110811930.5A CN202110811930A CN113552494A CN 113552494 A CN113552494 A CN 113552494A CN 202110811930 A CN202110811930 A CN 202110811930A CN 113552494 A CN113552494 A CN 113552494A
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- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 121
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 120
- 238000012360 testing method Methods 0.000 title claims abstract description 89
- 238000000034 method Methods 0.000 title claims abstract description 29
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 41
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 41
- 125000004122 cyclic group Chemical group 0.000 claims abstract description 32
- 238000000926 separation method Methods 0.000 claims abstract description 9
- 238000007599 discharging Methods 0.000 claims description 27
- 238000010998 test method Methods 0.000 claims description 20
- 238000001556 precipitation Methods 0.000 claims description 11
- 230000009467 reduction Effects 0.000 claims description 4
- 230000008569 process Effects 0.000 description 8
- 238000012795 verification Methods 0.000 description 7
- QHGJSLXSVXVKHZ-UHFFFAOYSA-N dilithium;dioxido(dioxo)manganese Chemical compound [Li+].[Li+].[O-][Mn]([O-])(=O)=O QHGJSLXSVXVKHZ-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000013508 migration Methods 0.000 description 2
- 230000005012 migration Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
- 230000003446 memory effect Effects 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000013522 software testing Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
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- 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]
- G01R31/385—Arrangements for measuring battery or accumulator variables
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- 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
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- 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
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Abstract
The embodiment of the application provides a low-temperature step charging method and a testing method of a lithium ion battery, wherein the low-temperature step charging testing method comprises the following steps: for at least two groups of lithium ion batteries which are placed in the same target low-temperature environment and are in an empty state, carrying out cyclic charge and discharge tests on each group according to respective set test conditions comprising different charging currents and different charging cut-off voltages; respectively disassembling the battery cell of each group of lithium ion batteries subjected to the cyclic charge and discharge test, and determining whether the negative electrode interface of the battery cell disassembled in the corresponding group is subjected to lithium analysis; and if no lithium separation occurs on the negative electrode interface of each group of the battery cells, selecting different charging currents and different charging cut-off voltages in each group as charging parameters of different stages, wherein the charging parameters of the different stages are used for generating the low-temperature step charging rule of the lithium ion battery. The method can obtain the step charging rule of the lithium ion battery in the low-temperature environment, and is reliable and high in efficiency.
Description
Technical Field
The application relates to the technical field of lithium ion batteries, in particular to a low-temperature step charging method and a testing method of a lithium ion battery.
Background
The lithium ion battery has the advantages of high voltage, high specific energy, long charging and discharging life, no memory effect, environmental friendliness and the like, and is widely applied to various fields of industrial production, life and the like. With the wider application of the lithium ion battery, the requirement of the client using end on the charge and discharge performance of the lithium ion battery at low temperature is higher and higher. The dynamic performance of the lithium ion battery at low temperature is poor, the viscosity of the electrolyte is increased, the conductivity is reduced, the ion migration rate is reduced, and the performance of the lithium ion battery at low temperature is poor and the risk of lithium precipitation is high due to the factors. In conventional solutions, the enterprise generally provides for the customer to charge at low temperatures using very low current (e.g., 0.05C), but this requires long charging times and less customer satisfaction. Especially to the two-wheel vehicle market, the module design does not have heating device, and the low temperature condition of charging is more severe. In order to meet the requirements of customers and not sacrifice the performance of the battery, a method for low-temperature stepped charging is needed, which can ensure the low-temperature charging efficiency, reduce the risk of lithium precipitation and reduce the potential safety hazard.
Disclosure of Invention
The embodiment of the application provides a low-temperature stepped charging method and a testing method for a lithium ion battery.
The embodiment of the application provides a low-temperature stepped charging test method for a lithium ion battery, which comprises the following steps:
for at least two groups of lithium ion batteries which are placed in the same target low-temperature environment and are in an empty state, carrying out cyclic charge and discharge tests on each group according to respective set test conditions comprising different charging currents and different charging cut-off voltages;
respectively disassembling the electric core of each group of the lithium ion batteries subjected to the cyclic charge and discharge test, and determining whether the negative electrode interface of the electric core disassembled in the corresponding group is subjected to lithium analysis;
and if no lithium separation occurs on the negative electrode interface of each group of the battery cells, selecting the different charging currents and the different charging cut-off voltages in each group as the charging parameters of different stages during charging in the target low-temperature environment, wherein the charging parameters of different stages are used for generating the low-temperature step charging rule of the lithium ion battery.
In some embodiments, the lithium ion battery low-temperature step charging test method further comprises:
if the lithium analysis occurs on the negative electrode interface of the battery cell of the corresponding group, reducing the charging current and/or the charging cut-off voltage in the testing condition of the corresponding group according to a preset reduction gradient, and re-performing the cyclic charging and discharging test on the lithium ion battery for replacing the corresponding group according to the testing condition comprising the reduced charging current and/or the reduced charging cut-off voltage until the corresponding charging current and the corresponding charging cut-off voltage when the lithium analysis does not occur are tested;
and selecting the charging current and the charging cut-off voltage of each group when no lithium precipitation occurs as the charging parameters of different stages during charging in the target low-temperature environment.
In some embodiments, each of the groups performs a cyclic charge and discharge test according to a set test condition including different charge currents and different charge cut-off voltages, and before performing the cyclic charge and discharge test, the method further includes:
the method comprises the steps of obtaining the constant volume capacity of a plurality of groups of lithium ion batteries at normal temperature, discharging at least two groups of lithium ion batteries with the same constant volume capacity to an empty state, placing the at least two groups of lithium ion batteries in the same target low-temperature environment for shelving until the actual temperature of the at least two groups of lithium ion batteries reaches the target low temperature.
In some embodiments, when the number of the lithium ion batteries is N groups, the test conditions of the i-th group of the lithium ion batteries comprise the i-th charging current, the i-th charging cut-off voltage, a charging current threshold value and a discharging current, and i is greater than or equal to 1 and less than or equal to N; and each group respectively carries out cyclic charge and discharge tests according to the test conditions which are respectively set and comprise different charging currents and different charging cut-off voltages, and the cyclic charge and discharge tests comprise:
for the ith group of lithium ion batteries, charging to the ith charging cut-off voltage in a constant current mode by using the ith charging current, charging to the current and reducing to the charging current threshold value in a constant voltage mode under the ith charging cut-off voltage, and discharging to a no-load state by using the discharging current after the preset time length is set aside; and repeating the steps for preset times in a circulating manner, then charging the ith group of lithium ion batteries to a full-charge state by utilizing the charging current threshold value, and finishing the circulating charging and discharging operation.
In some embodiments, the ith charging current is greater than the (i + 1) th charging current.
In some embodiments, the ith charge cutoff voltage is less than the (i + 1) th charge cutoff voltage, and the (i + 1) th charge cutoff voltage is less than or equal to a full electrical cutoff voltage of the lithium ion battery.
In some embodiments, the ith charging current is greater than the (i + 1) th charging current, and the ith charge cutoff voltage is less than the (i + 1) th charge cutoff voltage.
In some embodiments, the value range of the ith charging current is less than or equal to 0.5C; the value range of the (i + 1) th charging current is less than 0.5C.
In some embodiments, the charging current threshold has a value in a range of 0.05C or less.
In some embodiments, the discharge current is less than a rated current of the lithium ion battery at a normal temperature.
In some embodiments, the target low temperature environment is less than 0 ℃.
In some embodiments, the preset duration is greater than 2 h.
In some embodiments, the predetermined number of times is equal to or greater than 5 times.
The embodiment of the present application further provides a low-temperature step charging method for a lithium ion battery, including: charging is carried out according to the low-temperature step charging rule obtained by the method.
The embodiment of the application has the following beneficial effects:
the lithium ion battery low-temperature stepped charging test method of the embodiment utilizes at least two groups of batteries to synchronously perform cyclic charging and discharging tests of different charging currents and different charging cut-off voltages, and directly judges whether set charging parameters are suitable from a lithium analysis state of a disassembly interface in a battery cell disassembly mode, so that the method is simple, direct and real, and is applicable to all lithium ion batteries. Moreover, through directly screening the most suitable condition of charging earlier from electric core aspect, compare the current verification mode of charging from module or whole package rank etc. this scheme is more reliable, efficiency of software testing is higher.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
Fig. 1 shows a schematic flow chart of a low-temperature step charging test method for a lithium ion battery according to an embodiment of the present application;
fig. 2 shows a schematic flow chart of a low-temperature step charging test method for a lithium ion battery according to an embodiment of the present application;
fig. 3 shows a schematic test flow diagram of a lithium ion battery low-temperature step charging test method based on two groups of lithium ion batteries according to an embodiment of the present application;
fig. 4 shows a test result schematic diagram of the low-temperature step charging test method for the lithium ion battery according to the embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.
The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.
Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present application, are intended to indicate only specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present application belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments.
Example 1
Referring to fig. 1, the present embodiment provides a method for testing low-temperature step charging of a lithium ion battery, which can be applied to various lithium ion batteries, such as lithium manganate batteries, lithium iron phosphate batteries, and the like, to obtain a step charging rule under a specific low-temperature environment.
Exemplarily, the lithium ion battery low-temperature step charging test method includes steps S110 to S130:
step S110, for at least two groups of lithium ion batteries which are placed in the same target low-temperature environment and are in an empty state, each group respectively carries out cyclic charge and discharge tests according to the test conditions which are respectively set and comprise different charging currents and different charging cut-off voltages.
The target low-temperature environment mainly depends on the actual ambient temperature of the user when charging the lithium ion battery, and may be, for example, lower than 0 ℃, specifically, for example, -5 ℃, -10 ℃, or-20 ℃, which is determined according to the actual usage environment. The empty state refers to a state after the battery is completely discharged.
In this embodiment, the determination of the number of test sets of the lithium ion battery may be determined according to the dividing requirement of the charging stage of the lithium ion battery. For example, if the charging process of the battery at a low temperature is divided into three stages, namely an initial stage, an intermediate stage and a final stage, then, for the first two charging stages, two groups of lithium ion batteries can be selected for simultaneous testing to determine different charging batteries and different charging cut-off voltages of the two stages in a low-temperature environment; for the final stage, the charging can be slowly carried out until full, usually at a preset small current.
It is understood that the above three-stage division is only an example, and in the actual use process, the charging process of the lithium ion battery can be divided into more charging gradients. Generally, the more gradients, the higher the accuracy of the charging control, and the more complicated the charging control will be.
The test conditions mainly refer to specific setting parameters for performing cyclic charge and discharge on a group of lithium ion batteries, and for example, the test conditions may include, but are not limited to, a charge current and a charge cut-off voltage of the lithium ion battery at an initial stage of charge, a charge current threshold at a final stage of charge, a discharge current in a discharge process, the number of cyclic charge and discharge, a standing time before discharge, and the like.
Based on the above test parameters, the present embodiment mainly controls the charging current and the charging cut-off voltage of each group at the initial charging stage to be different, and other test parameters are the same, so as to better test the charging current and the charging cut-off voltage required at different stages, and further obtain the step charging rule of the lithium ion battery at the target low temperature.
For the step S110, exemplarily, at least two groups of lithium ion batteries in the empty state are placed in the same low-temperature environment, and test conditions including different charging currents and different charging cut-off voltages are set for each group, and then each group is respectively subjected to the cyclic charge and discharge test according to the respective test conditions. It can be understood that, through the synchronous test of a plurality of groups of batteries, on one hand, the two parameters can be better subjected to gradient adjustment and verification, on the other hand, the charging parameters of the batteries at different stages in the target low-temperature environment can be obtained more quickly, and the test efficiency is improved.
Taking the cyclic charge and discharge test of N groups of lithium ion batteries as an example, for the ith group of lithium ion batteries, the test conditions include the ith charge current, the ith charge cut-off voltage, the charge current threshold and the discharge current, wherein i is greater than or equal to 1 and less than or equal to N. Then, the cyclic charge and discharge test is performed on each set of the above-mentioned steps S110 according to the test conditions set for each set, and the cyclic charge and discharge test includes:
for the ith group of lithium ion batteries, charging to the ith charging cut-off voltage in a constant current mode by using the ith charging current corresponding to the ith group of lithium ion batteries, charging to the current falling to the charging current threshold value in a constant voltage mode under the ith charging cut-off voltage, and discharging to the empty state by using the discharging current after the preset time length is set aside; and repeating the steps for preset times in a circulating manner, then charging the ith group of lithium ion batteries to a full-charge state by utilizing the charging current threshold value, and finishing the circulating charging and discharging operation.
In an embodiment, for a plurality of groups of batteries to be tested synchronously, the charging current parameters of each group may be divided into gradients in advance, so that when the charging current parameters need to be readjusted for repeated verification, values may be taken from a corresponding preset gradient range, so that the parameters of the corresponding charging stage may be determined more quickly. Exemplarily, the ith charging current may be set to be larger than the (i + 1) th charging current, that is, the parameter of the charging current of the ith group of lithium ion batteries may be larger than the charging current of the (i + 1) th group.
For example, the charging current multiplying power of some types of lithium ion batteries can be selected from the range of 0.1C to 0.5C, and if two groups are used for the charging test, the charging test can be divided into: the charging current of the first group of batteries can be selected from the range of 0.3C-0.5C, the charging current of the second group of batteries can be selected from the range of 0.3C-0.1C, and the like, and in the actual test process, the value test can be carried out according to the selection mode of the charging current from large to small. This allows a fast finding of a suitable charging current in both the larger and smaller current intervals.
For the above charge cut-off voltage, similarly, in an embodiment, the ith charge cut-off voltage may be set to be smaller than the (i + 1) th charge cut-off voltage, that is, the charge cut-off voltage parameter of the ith group of lithium ion batteries may be larger than the charge cut-off voltage parameter of the (i + 1) th group. Further, the i +1 th charge cut-off voltage is less than or equal to a full-electric cut-off voltage of the lithium ion battery, wherein the full-electric cut-off voltage is a voltage when the battery is fully charged.
In another embodiment, the ith charging current may be set to be greater than the (i + 1) th charging current, and the ith charging cutoff voltage may be set to be less than the (i + 1) th charging cutoff voltage, for example. Because the voltage of the battery can change along with the continuous charging of the charging current in the charging process, the battery is tested and adjusted together by combining two parameters of the charging current and the charging cut-off voltage, and the actual charging condition is better met.
The range of the multiplying factor of the charging current threshold may be less than or equal to 0.05C, for example, generally selected to be 0.02C to 0.05C. The preset time period is usually greater than 2h, and may be 12h, 16h, etc. The predetermined number is usually greater than or equal to 5 times, for example, 5 to 10 times. It will be appreciated that the above test parameters may be adaptively adjusted according to actual requirements.
When the set charging current and the set charging cut-off voltage are not proper, if the lithium ion battery is subjected to continuous charging and discharging operations, the lithium precipitation phenomenon is easily caused because the viscosity of the electrolyte of the battery is increased, the conductivity is reduced, and the ion migration rate is reduced. Therefore, after the cyclic charge and discharge test is performed, the battery cell is disassembled, and whether lithium separation occurs on the battery cell negative electrode interface is observed, that is, step S120 is performed, so that whether the current charge current and the charge cut-off voltage are appropriate can be determined.
In addition, before the cyclic charge and discharge test is performed, some pretreatment operations are required to be performed on the lithium ion battery to be tested, and further, as shown in fig. 2, before the cyclic charge and discharge test operation of step S110 is performed, the method further includes:
and step S140, obtaining the constant volume capacities of a plurality of groups of lithium ion batteries at normal temperature, discharging at least two groups of lithium ion batteries with the same constant volume capacity to an empty state, and placing the at least two groups of lithium ion batteries in the same target low-temperature environment for shelving until the actual temperatures of the at least two groups of lithium ion batteries reach the target low temperature.
In consideration of the fact that the capacities of the single batteries are different, in order to ensure the accuracy of the test result, the lithium ion batteries with the same capacity are selected for the charging test, so that the consistency of the groups of lithium ion batteries for the charging test can be ensured, and the comparability and the reliability of the obtained test data are further ensured.
Exemplarily, for a plurality of groups of lithium ion batteries, at normal temperature, a test can be performed according to the test specification of the battery specification to obtain respective constant volume capacities of the plurality of groups of batteries, and a plurality of groups of lithium ion batteries with the same capacity are selected from the constant volume capacities. And then, the selected lithium ion batteries are completely discharged, namely, the lithium ion batteries are discharged to an empty state, and then the discharged lithium ion batteries are placed at the target environment temperature and are kept stand for a period of time until the temperature of the lithium ion batteries to be tested is the same as the target environment temperature, so that the problem that the test results are inaccurate due to different initial temperatures of the batteries can be avoided, and the reliability of the test results is further ensured.
And step S120, respectively disassembling the battery cores of each group of lithium ion batteries subjected to the cyclic charge and discharge test, and determining whether the negative electrode interface of the battery core disassembled in the corresponding group is subjected to lithium analysis.
In order to determine whether the currently set charging current and the currently set charging cutoff voltage of each group of lithium ion batteries are suitable, the present embodiment determines from the cell level, that is, determines the reliability of the charging scheme from the lithium precipitation state of the cell negative plate interface in a cell disassembly manner, which is simple and direct in manner, and can more truly reflect the actual charging situation.
Exemplarily, each group of lithium ion batteries can be disassembled, and whether precipitated lithium exists on the negative electrode interface of the corresponding group of battery cells is observed. If not, the set charging scheme is indicated to be appropriate. On the contrary, if the voltage value is greater than the threshold voltage, the charging current and the charging cutoff voltage are not appropriate, and further adjustment is required.
Step S130, if no lithium precipitation occurs on the negative electrode interface of each group of the battery cells, selecting different charging currents and different charging cut-off voltages in each group as charging parameters of different stages during charging in the target low-temperature environment, wherein the charging parameters of the different stages are used for generating a low-temperature step charging rule of the lithium ion battery.
Exemplarily, if no lithium separation phenomenon occurs in each group, the charging current and the charging cutoff voltage of the corresponding group can be selected as the charging parameters of different stages, and then the low-temperature step charging rule of the lithium ion battery in the target low-temperature environment is generated by using the charging parameters of different stages.
For example, still taking the above three-stage division as an example, if no lithium deposition occurs in two groups of lithium ion batteries, the charging current and the charging cut-off voltage of the first group may be used as the charging parameters of the initial stage, the charging current and the charging cut-off voltage of the second group may be used as the charging parameters of the intermediate stage, and the preset charging current threshold and the battery full-charge cut-off voltage may be used as the charging parameters of the final stage.
As an alternative, if there is lithium precipitation on the negative electrode interface of the battery cell of the corresponding group, the charging current and the charging cut-off voltage in the test condition of the corresponding group may be reduced according to a preset reduction gradient. For example, taking the value range of the charging current multiplying factor of the second group of batteries as 0.3C to 0.1C as an example, if the current charging current multiplying factor of the second group is 0.28C, a smaller value can be selected within the interval of 0.3C to 0.1C, such as a reduction to 0.25C, 0.2C, and the like.
And then, according to the test conditions including the reduced charging current and the reduced charging cut-off voltage, the step of carrying out the cyclic charging and discharging test on the lithium ion battery for replacing the corresponding group again until the charging current and the charging cut-off voltage corresponding to the condition that lithium precipitation does not occur are tested. It will be appreciated that the use of another lithium ion cell, instead of the cell in which lithium extraction occurs, should be tested under test conditions in which the parameters are the same as the set except for the two adjusted parameters.
And finally, selecting the charging current and the charging cut-off voltage which are determined when no lithium separation occurs in each group as the charging parameters of different stages during charging in the target low-temperature environment.
The following describes the test method in detail by taking the test process of two sets of lithium ion batteries as an example.
As shown in fig. 3, when 2 groups of batteries are selected for the cyclic charge and discharge test, for the group 1 lithium ion battery, the test conditions include a first charge current I1, a first charge cut-off voltage V1, and a charge current threshold I0And a discharge current Ic, for the group 2 lithium ion battery, the test conditions include a second charge current I2 and a second charge cut-off voltage V2, and other parameters are the same as those of the group 1, wherein, I1>I2，V1<V2。
Thus, for group 1 and group 2 lithium ion batteries, there are: for group 1 lithium ion batteries, charging is performed in a constant current mode to a charge cutoff voltage V1 using a charge current I1, and in a constant voltage mode at a charge cutoff voltage V1 until the current drops to a charge current threshold I0After the preset time period is set aside, discharging is carried out to the empty state by utilizing the discharge current Ic; repeating the above steps for a preset number of times, and then utilizing the charging current threshold I0Charging the 1 st group of lithium ion batteries to a full-electric cut-off voltage V0I.e. a full-charge state, then disassembling and observing whether lithium is separated from the cathode interface of the battery core.
For group 2 lithium ion batteries, the battery is charged in a constant current mode to a charge cutoff voltage V2 using a charge current I2, and in a constant voltage mode at a charge cutoff voltage V2 until the current drops to a charge current threshold I0After the preset time period is set aside, discharging is carried out to the empty state by utilizing the discharge current Ic; the above-mentioned steps are repeated, and then,circulating for preset times, and reusing charging current threshold I0Charging the 2 nd group of lithium ion batteries to a full-charge state, then disassembling and observing whether lithium is separated from the negative electrode interface of the battery core;
if no lithium precipitation occurs in the two groups of disassembling results, the scheme is effective, and the low-temperature step charging rule can be generated at the moment, I1 and V1 are used as charging parameters of the first stage, I2 and V2 are used as charging parameters of the second stage, and I0And V0As the charging parameter for the third stage. On the contrary, if one or two groups of the groups have lithium separation, the scheme is invalid, the charging current and the charging cut-off voltage of the group with the lithium separation need to be reduced and adjusted, and the verification is carried out again according to the test steps until the scheme that the lithium separation does not occur in the two groups is obtained, and at this time, the corresponding low-temperature step charging rule can be determined.
For example, fig. 4 shows the results of tests performed on two groups of lithium manganate batteries under a low temperature environment of-5 ℃. Specifically, verification is carried out based on lithium manganate batteries, two qualified batteries are selected, the constant volume capacity is determined at the normal temperature by the charge-discharge rate of 1C, and the batteries are placed for 16 hours at the temperature of minus 5 ℃ to reach the target temperature. For the 1 st group of batteries, charging the batteries to 4.1V at a constant current and a constant voltage of 0.33C, stopping charging at 0.05C, standing for 3 hours, and then discharging the batteries to 2.7V at 0.5C, wherein the charging and discharging are circulated for 5 times in the way; after cyclic charge and discharge, charging to 4.2V by using 0.05C; and then, disassembling the electric core, and observing whether lithium is separated from the surface of the negative electrode.
For the 2 nd group of batteries, constant current and voltage are carried out at 0.2C until the voltage reaches 4.18V, the voltage is cut off at 0.05C, and the batteries are placed for 3 hours; discharging to 2.7V at 0.5C, and circulating for 5 times; after cyclic charge and discharge, charging to 4.2V by using 0.05C; and then, disassembling the electric core, and observing whether lithium is separated from the surface of the negative electrode.
As can be seen from fig. 4, when the charging current magnification and the charge cut-off voltage of group 1 were 0.33C and 4.10V, respectively, the disassembled interface was good and no lithium was precipitated; when the charging current multiplying power and the charging cut-off voltage of the group 2 are 0.2C and 4.18V, the interface is disassembled to precipitate lithium. It can be seen that the set 2 approach is not available. Further, based on the embodiment of group 2, the test was conducted again while adjusting the charge cutoff voltage to 4.15V without adjusting the charge current ratio, and the result was that the disassembled interface was good. And further, according to various groups of test parameters when lithium is not separated out, the low-temperature step charging rule of the lithium ion battery at the temperature of-5 ℃ can be obtained.
By analogy, for other low-temperature environments such as-10 ℃, 20 ℃ and the like, test verification of different charging multiplying powers and different charging cut-off voltages can be performed according to the method of the embodiment, so that the low-temperature stepped charging rule at the corresponding temperature is obtained.
The lithium ion battery low-temperature stepped charging test method of the embodiment synchronously performs the cyclic charging and discharging tests of different charging currents and different charging cut-off voltages by using at least two groups of batteries, and directly judges whether the set charging parameters are suitable from the lithium analysis state of the disassembly interface in a battery cell disassembly mode, so that the mode is simple, direct and real, and the scheme is suitable for all lithium ion batteries. Moreover, current pack into the module with electric core or carry out the method that the scheme of charging was verified after whole package rank, the cycle length, low efficiency, it is with high costs, this is because the scheme in case the inefficacy then need get back to electric core rank again and carry out the analysis verification, the scheme of this application is direct to select the most suitable condition of charging earlier from the electric core aspect, and can eliminate unqualified electric core in the front, again with qualified electric core charging in groups, can reduce the risk that the negative pole lithium is analysed out in low temperature charging like this, and is more reliable, efficiency is higher.
Example 2
The embodiment of the present application further provides a low-temperature step charging method for a lithium ion battery, exemplarily, the test method of the above embodiment 1 may be used for obtaining a low-temperature step charging rule in a target low-temperature environment for the lithium ion battery, and then the low-temperature step charging rule is used for performing stage charging.
It can be understood that, for the low-temperature stepped charging rule obtained by the low-temperature stepped charging test method, the charging is carried out by adopting a larger current multiplying factor in a low SOC (battery charge) state, so that the charging time can be effectively shortened, and meanwhile, the charging multiplying factor is reduced along with the increase of the charging SOC, so that the lithium precipitation risk of the battery in the whole charging process can be ensured, and the potential safety hazard of charging and the like can be reduced. On the other hand, the charging is carried out according to the charging rule, and the effect of improving the low-temperature performance of the battery can be achieved by changing the low-temperature charging mode under the condition of not changing the original structure and chemical system of the lithium ion battery.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application.
Claims (10)
1. A low-temperature step charging test method for a lithium ion battery is characterized by comprising the following steps:
for at least two groups of lithium ion batteries which are placed in the same target low-temperature environment and are in an empty state, carrying out cyclic charge and discharge tests on each group according to respective set test conditions comprising different charging currents and different charging cut-off voltages;
respectively disassembling the electric core of each group of the lithium ion batteries subjected to the cyclic charge and discharge test, and determining whether the negative electrode interface of the electric core disassembled in the corresponding group is subjected to lithium analysis;
and if no lithium separation occurs on the negative electrode interface of each group of the battery cells, selecting the different charging currents and the different charging cut-off voltages in each group as the charging parameters of different stages during charging in the target low-temperature environment, wherein the charging parameters of different stages are used for generating the low-temperature step charging rule of the lithium ion battery.
2. The lithium ion battery low-temperature step charging test method according to claim 1, further comprising:
if the lithium analysis occurs on the negative electrode interface of the battery cell of the corresponding group, reducing the charging current and/or the charging cut-off voltage in the testing condition of the corresponding group according to a preset reduction gradient, and re-performing the cyclic charging and discharging test on the lithium ion battery for replacing the corresponding group according to the testing condition comprising the reduced charging current and/or the reduced charging cut-off voltage until the corresponding charging current and the corresponding charging cut-off voltage when the lithium analysis does not occur are tested;
and selecting the charging current and the charging cut-off voltage of each group when no lithium precipitation occurs as the charging parameters of different stages during charging in the target low-temperature environment.
3. The lithium ion battery low-temperature step charging test method according to claim 1, wherein each group is respectively subjected to a cyclic charging and discharging test according to respective set test conditions including different charging currents and different charging cutoff voltages, and the method further comprises the following steps:
the method comprises the steps of obtaining the constant volume capacity of a plurality of groups of lithium ion batteries at normal temperature, discharging at least two groups of lithium ion batteries with the same constant volume capacity to an empty state, placing the at least two groups of lithium ion batteries in the same target low-temperature environment for shelving until the actual temperature of the at least two groups of lithium ion batteries reaches the target low temperature.
4. The lithium ion battery low-temperature step charging test method according to any one of claims 1 to 3, wherein when the number of the lithium ion batteries is N groups, the test conditions of the i-th group of lithium ion batteries include i-th charging current, i-th charging cut-off voltage, charging current threshold value and discharging current, i is greater than or equal to 1 and less than or equal to N; and each group respectively carries out cyclic charge and discharge tests according to the test conditions which are respectively set and comprise different charging currents and different charging cut-off voltages, and the cyclic charge and discharge tests comprise:
for the ith group of lithium ion batteries, charging to the ith charging cut-off voltage in a constant current mode by using the ith charging current, charging to the current and reducing to the charging current threshold value in a constant voltage mode under the ith charging cut-off voltage, and discharging to a no-load state by using the discharging current after the preset time length is set aside; and repeating the steps for preset times in a circulating manner, then charging the ith group of lithium ion batteries to a full-charge state by utilizing the charging current threshold value, and finishing the circulating charging and discharging operation.
5. The lithium ion battery low-temperature step charging test method according to claim 4, wherein the ith charging current is greater than the (i + 1) th charging current; the ith charging cut-off voltage is less than the (i + 1) th charging cut-off voltage, and the (i + 1) th charging cut-off voltage is less than or equal to the full-charge cut-off voltage of the lithium ion battery.
6. The lithium ion battery low-temperature step charging test method according to claim 4, wherein the value range of the ith charging current is less than or equal to 0.5C; the value range of the (i + 1) th charging current is less than 0.5C.
7. The lithium ion battery low-temperature step charging test method according to claim 4, wherein the value range of the charging current threshold is less than or equal to 0.05C.
8. The lithium ion battery low-temperature step charging test method according to claim 4, wherein the discharge current is smaller than a rated current of the lithium ion battery at normal temperature.
9. The lithium ion battery low temperature step charge testing method of claim 4, wherein the target low temperature environment is below 0 ℃; the preset time is longer than 2 h; the preset times are more than or equal to 5 times.
10. A low-temperature step charging method for a lithium ion battery is characterized by comprising the following steps: charging according to the low temperature step charging regime obtained by the method of any one of claims 1-8.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114325448A (en) * | 2021-12-30 | 2022-04-12 | 星恒电源股份有限公司 | Evaluation method, device, computer equipment and readable storage medium of lithium battery |
| CN115101838A (en) * | 2022-06-16 | 2022-09-23 | 岳阳耀宁新能源科技有限公司 | A kind of low temperature charging method of lithium ion battery |
| CN116500467A (en) * | 2023-04-12 | 2023-07-28 | 国民技术股份有限公司 | Method and device for detecting battery charging capability in low-temperature interval |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102097656A (en) * | 2010-12-19 | 2011-06-15 | 重庆戴徕密客电源有限公司 | Method for forming high-capacity lithium iron phosphate lithium ion battery |
| JP2015104138A (en) * | 2013-11-20 | 2015-06-04 | 株式会社Ｗａｖｅ Ｔｅｃｈｎｏｌｏｇｙ | Secondary battery charging method and charging device using the same |
| CN106805363A (en) * | 2017-03-06 | 2017-06-09 | 合肥红佳科技信息有限公司 | A kind of electromagnetism fills can sport footwear |
| CN107146918A (en) * | 2017-06-26 | 2017-09-08 | 浙江大学 | A pulse charging method applied to lithium metal batteries |
| KR20170105320A (en) * | 2016-03-09 | 2017-09-19 | 주식회사 엘지화학 | Charging Method of Secondary Battery and Charging Apparatus of the Same |
| CN109728371A (en) * | 2018-12-29 | 2019-05-07 | 上海卡耐新能源有限公司 | A kind of power soft pack cell ladder charge control mode |
| CN111883865A (en) * | 2020-07-31 | 2020-11-03 | 合肥国轩高科动力能源有限公司 | Low-temperature charging method for lithium ion battery |
| CN112436202A (en) * | 2020-10-22 | 2021-03-02 | 中车长春轨道客车股份有限公司 | Stepped current charging method for preventing lithium precipitation of lithium ion battery cathode |
| WO2021056687A1 (en) * | 2019-09-29 | 2021-04-01 | 宁德新能源科技有限公司 | Charging method, electronic device, and storage medium |
| CN112666482A (en) * | 2020-12-24 | 2021-04-16 | 合肥国轩高科动力能源有限公司 | Method and system for testing cycle life of lithium ion battery |
-
2021
- 2021-07-19 CN CN202110811930.5A patent/CN113552494B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102097656A (en) * | 2010-12-19 | 2011-06-15 | 重庆戴徕密客电源有限公司 | Method for forming high-capacity lithium iron phosphate lithium ion battery |
| JP2015104138A (en) * | 2013-11-20 | 2015-06-04 | 株式会社Ｗａｖｅ Ｔｅｃｈｎｏｌｏｇｙ | Secondary battery charging method and charging device using the same |
| KR20170105320A (en) * | 2016-03-09 | 2017-09-19 | 주식회사 엘지화학 | Charging Method of Secondary Battery and Charging Apparatus of the Same |
| CN106805363A (en) * | 2017-03-06 | 2017-06-09 | 合肥红佳科技信息有限公司 | A kind of electromagnetism fills can sport footwear |
| CN107146918A (en) * | 2017-06-26 | 2017-09-08 | 浙江大学 | A pulse charging method applied to lithium metal batteries |
| CN109728371A (en) * | 2018-12-29 | 2019-05-07 | 上海卡耐新能源有限公司 | A kind of power soft pack cell ladder charge control mode |
| WO2021056687A1 (en) * | 2019-09-29 | 2021-04-01 | 宁德新能源科技有限公司 | Charging method, electronic device, and storage medium |
| CN111883865A (en) * | 2020-07-31 | 2020-11-03 | 合肥国轩高科动力能源有限公司 | Low-temperature charging method for lithium ion battery |
| CN112436202A (en) * | 2020-10-22 | 2021-03-02 | 中车长春轨道客车股份有限公司 | Stepped current charging method for preventing lithium precipitation of lithium ion battery cathode |
| CN112666482A (en) * | 2020-12-24 | 2021-04-16 | 合肥国轩高科动力能源有限公司 | Method and system for testing cycle life of lithium ion battery |
Non-Patent Citations (2)
| Title |
|---|
| YUE GAO 等: "Low-temperature and high-rate-charging lithium metal batteries enabled by an electrochemically active monolayer-regulated interface", 《NATURE ENERGY》, 2 June 2020 (2020-06-02), pages 534, XP037195780, DOI: 10.1038/s41560-020-0640-7 * |
| 阮海军: "低温环境下锂离子电池优化加热及充电方法研究", 《中国博士学位论文全文数据库工程科技Ⅱ辑, 15 April 2021 (2021-04-15), pages 042 - 31 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114325448A (en) * | 2021-12-30 | 2022-04-12 | 星恒电源股份有限公司 | Evaluation method, device, computer equipment and readable storage medium of lithium battery |
| CN115101838A (en) * | 2022-06-16 | 2022-09-23 | 岳阳耀宁新能源科技有限公司 | A kind of low temperature charging method of lithium ion battery |
| CN116500467A (en) * | 2023-04-12 | 2023-07-28 | 国民技术股份有限公司 | Method and device for detecting battery charging capability in low-temperature interval |
| CN116500467B (en) * | 2023-04-12 | 2024-01-26 | 国民技术股份有限公司 | Method and device for detecting battery charging capability in low-temperature interval |
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