CN107884484A - A kind of assay method of electrodes of lithium-ion batteries NMP contents - Google Patents
A kind of assay method of electrodes of lithium-ion batteries NMP contents Download PDFInfo
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- CN107884484A CN107884484A CN201710906650.6A CN201710906650A CN107884484A CN 107884484 A CN107884484 A CN 107884484A CN 201710906650 A CN201710906650 A CN 201710906650A CN 107884484 A CN107884484 A CN 107884484A
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- nmp
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/04—Preparation or injection of sample to be analysed
- G01N30/06—Preparation
Abstract
The invention belongs to technical field of lithium ion, more particularly in a kind of electrodes of lithium-ion batteries NMP contents assay method, it includes sample pre-treatments step, treats test sample extraction step, standard liquid preparation steps, draws standard curve step and treat test sample testing procedure.Compared to prior art, the present invention is extracted the N methyl pyrrolidones (NMP) in pole piece by ultrasonic extraction, and after filtering, purifying, prepare liquid is separated by gas chromatography-mass spectrometry, select NMP characteristic ion, using quantified by external standard method, so as to accurately measure the content of NMP in battery pole piece, the present invention is simple to operate, detection limit is low, it is reproducible, good monitoring effect is played in lithium ion battery manufacturing process, is had broad application prospects.
Description
Technical field
The invention belongs to technical field of lithium ion, more particularly to a kind of measure of electrodes of lithium-ion batteries NMP contents
Method.
Background technology
Lithium ion battery because have the advantages that energy density is high, operating voltage is big, good cycle, memory-less effect and by
It is widely used in the fields such as electronic digital product, power vehicle, and important component of the pole piece as lithium ion battery, to electricity
The performance impact in pond is very big, and in general the uniformity of pole piece directly influences battery with two side terminals.
Wherein, pole piece generally comprises collector and is coated on the active material coating of collection liquid surface, and active material applies
Layer slurry is typically made up of active material, binding agent and solvent etc..Because 1-METHYLPYRROLIDONE (NMP) has good dissolving
Property, it is the good solvent of pole coating, thus be widely used on lithium ion battery.Because NMP is only applied to pole as solvent
Piece coating layer, therefore before subsequent processing is entered, typically removed NMP by the way of pole piece is toasted, to avoid NMP from remaining in
On pole piece, the cycle performance of battery otherwise can be made to be deteriorated, security performance declines.At present, because of the limitation of examined technology, lithium ion
Battery production business in process of production, is not distinctly claimed and NMP residual contents in pole piece is measured, also without quantization matter
Control index.But the Accurate Determining of NMP contents has of crucial importance to the chemical property for assessing electrodes of lithium-ion batteries and battery
Meaning.In view of this, it is necessory to research and develop it is a kind of can in accurate measurement electrodes of lithium-ion batteries NMP contents method.
Wherein, gas chromatograph-mass spectrometer (GC-MS) has very outstanding separating capacity, qualitative and quantitation capabilities, for NMP
There is relatively low detection limit, 0.02mg/L NMP signal to noise ratio is more than 50.Therefore, can be to the NMP of low content using external standard method
Carry out accurately quantitative.
The content of the invention
It is an object of the invention to：In view of the shortcomings of the prior art, a kind of electrodes of lithium-ion batteries NMP contents are provided
Assay method, the assay method can carry out accurately quantitative to NMP contents in battery pole piece.
To achieve these goals, the present invention uses following technical scheme：
A kind of assay method of electrodes of lithium-ion batteries NMP contents, it comprises the following steps：
Step 1), sample pre-treatments：Take a pole piece to be measured, the NMP rich regions of pole piece to be measured cut out size for A ×
Acm sample；Wherein, A is positive integer；
Step 2), treat that test sample extracts：0.1~2g of sample of step 1) processing is weighed, and is put into sample bottle, adds 10
~50mL Extraction solvents, with instrument 0.5~2h of ultrasonic extraction is cleaned by ultrasonic, after the completion of ultrasonic, stand, be cooled to room temperature, use is organic
Test sample is treated in filtration core extracted by filtration liquid to sample injection bottle, acquisition；
Step 3), standard liquid are prepared：Using diluting step by step, pure material NMP is diluted to the work of at least five various concentrations
Make standard liquid, concentration range is 0.1~10mg/L；
Step 4), draw standard curve：The Working Standard Solution of step 3) is surveyed with gas chromatograph-mass spectrometer (GC-MS)
Examination, obtain standard curve；
Step 5), treat that test sample is tested：Step 2) is treated that test sample is tested with gas chromatograph-mass spectrometer (GC-MS), according to
The standard curve that step 4) obtains, measures the content for treating NMP in test sample.
Wherein, the chromatographic parameter of gas chromatograph-mass spectrometer (GC-MS) and mass spectrometry parameters are as follows：
Chromatographic parameter：Chromatographic column HP-5MS, (5% phenyl)-methyl polysiloxane, length 30m, internal diameter 0.25mm,
Thickness is 0.25um；Carrier gas：More than 99.999% helium；Injection port：250℃；Sample size：1uL；Split ratio：5:1；Constant current gas
Stream：1mL/min；Heating schedule：80 DEG C of initial temperature, 250 DEG C are raised to 30 DEG C/min speed, keeps 2min.
Mass spectrometry parameters：230 DEG C of ion source temperature；150 DEG C of quadrupole rod；250 DEG C of transmission line temperature；Solvent delay 2min；It is double
Channel scan：Scan scanning ranges, 10~200m/z, SIM scanning, quota ion 99, with reference to ion 98,44,70.
As the preferred scheme of the assay method of electrodes of lithium-ion batteries NMP contents of the present invention, NMP in pole piece
Content W is：Wherein, c is that what is measured treat the NMP concentration of test sample, mg/L；V is constant volume, mL；M is what is weighed
Pole piece quality, g.
As the preferred scheme of the assay method of electrodes of lithium-ion batteries NMP contents of the present invention, institute in step 1)
State the intermediate region that NMP rich regions are pole piece.
As the preferred scheme of the assay method of electrodes of lithium-ion batteries NMP contents of the present invention, institute in step 1)
Pole piece to be measured is stated to dry 2~6h pole piece after coating.
As the preferred scheme of the assay method of electrodes of lithium-ion batteries NMP contents of the present invention, institute in step 2)
State Extraction solvent for acetone, ethanol, methanol, n-butanol, methanol and ethanol, the tert-butyl alcohol, phenol, acetonitrile, ether, isopropyl ether, petroleum ether,
At least one of tetrahydrofuran, chloroform, ethyl acetate, butyl acetate.
As the preferred scheme of the assay method of electrodes of lithium-ion batteries NMP contents of the present invention, institute in step 2)
The power for stating ultrasonic cleaning instrument is 300~500W.
As the preferred scheme of the assay method of electrodes of lithium-ion batteries NMP contents of the present invention, institute in step 2)
The pore size for stating organic filter core is 0.2~0.8 μm.
The beneficial effects of the present invention are：The invention discloses a kind of measure side of NMP contents in electrodes of lithium-ion batteries
Method, the 1-METHYLPYRROLIDONE (NMP) in pole piece is extracted by ultrasonic extraction, after filtering, purifying, pass through gas phase color
Spectrum-GC-MS separation prepare liquid, NMP characteristic ion is selected, using quantified by external standard method, so as to accurately measure battery pole piece
Middle NMP content, the present invention is simple to operate, and detection limit is low, reproducible, and good prison is played in lithium ion battery manufacturing process
Survey acts on, and has broad application prospects.
Brief description of the drawings
Fig. 1 is the GC-MS 0.02mg/L of present invention NMP signal to noise ratio figures.
Fig. 2 is the NMP standard liquid chromatograms of the present invention.
Fig. 3 is NMP chromatograms in pole piece of the invention.
Embodiment
To make technical scheme and advantage clearer, below in conjunction with specific embodiment, to the skill of the present invention
Art scheme is clearly and completely described, it is clear that and described embodiment is part of the embodiment of the present invention, rather than all
Embodiment.Based on the embodiment in the present invention, those of ordinary skill in the art institute under the premise of creative work is not made
The every other embodiment obtained, belongs to the scope of protection of the invention.
Embodiment 1
Wherein, gas chromatograph-mass spectrometer (GC-MS) (GC-MS) parameter that the present embodiment uses is as follows：
GC-MS models：Agilent 7890B-5977B；
Chromatographic parameter：Chromatographic column HP-5MS, (5% phenyl)-methyl polysiloxane, length 30m, internal diameter 0.25mm,
Thickness is 0.25um；Carrier gas：More than 99.999% helium；Injection port：250℃；Sample size：1uL；Split ratio：5:1；Constant current gas
Stream：1mL/min；Heating schedule：80 DEG C of initial temperature, 250 DEG C are raised to 30 DEG C/min speed, keeps 2min；
Mass spectrometry parameters：230 DEG C of ion source temperature；150 DEG C of quadrupole rod；250 DEG C of transmission line temperature；Solvent delay 2min；It is double
Channel scan：Scan scanning ranges, 10~200m/z, SIM scanning, quota ion 99, with reference to ion 98,44,70.
Wherein, Fig. 1 is GC-MS 0.02mg/L NMP signal to noise ratio figures.
A kind of assay method of electrodes of lithium-ion batteries NMP contents of the present embodiment, it comprises the following steps：
1) prepared by prepare liquid：
The pole piece to be measured dried 4 hours after coating is cut into about 1cm × 1cm sizes, respectively weigh 3 it is parallel treat test sample in
Ultrasonic sample bottle, quality are respectively 0.6028g, 0.6018g, 0.6967g；
Toward the acetone equipped with accurate addition 25mL in the sample bottle for treating test sample, tightened with the bottle cap with silica gel sealing pad,
Sample bottle is placed in into ultrasound in ultrasonic washing instrument to be extracted within 0.5 hour, ultrasonic power 500W；
After the completion of ultrasound, sample bottle is moved on into vent cabinet, stands, be cooled to room temperature, with 0.45 μm of the organic filter in aperture
Core extracted by filtration liquid obtains prepare liquid into GC-MS sample injection bottles.
2) standard liquid is prepared：
Precise 0.0977g purity is 99.9% NMP, constant volume 100mL, obtains 976.0mg/L storing solution；
Using diluting step by step, it is respectively 0.4880mg/L, 0.9760mg/L, 1.9520mg/ that storing solution is configured into concentration
L, 4.8800mg/L, 9.7600mg/L Working Standard Solution.
3) draw standard curve and treat that test sample is tested：
Working Standard Solution is tested with GC-MS, draws standard curve；
Prepare liquid is tested with GC-MS, according to the standard curve of drafting, the content of NMP in prepare liquid can be measured, surveyed
Three parallel NMP contents for treating test sample are respectively 2.5146mg/L, 2.6259mg/L, 3.0925mg/L, finally can by following formula
Obtain the content W of NMP in pole piece；
Wherein：W be pole piece in NMP content, unit mg/kg；
C is the NMP concentration of the prepare liquid measured, unit mg/L；
V is constant volume, unit mL；
M be weigh pole piece quality, unit g.
The measurement result that above three is parallel to treat test sample is as shown in table 1.
The pole piece NMP assay results of the present embodiment of table 1
Wherein, Fig. 2 is the NMP standard liquid chromatograms of the present embodiment；Fig. 3 is NMP chromatograms in the pole piece of the present embodiment.
Embodiment 2
Wherein, gas chromatograph-mass spectrometer (GC-MS) (GC-MS) parameter that the present embodiment uses is as follows：
GC-MS models：Agilent 7890B-5977B；
Chromatographic parameter：Chromatographic column HP-5MS, (5% phenyl)-methyl polysiloxane, length 30m, internal diameter 0.25mm,
Thickness is 0.25um；Carrier gas：More than 99.999% helium；Injection port：250℃；Sample size：1uL；Split ratio：3:1；Constant current gas
Stream：1mL/min；Heating schedule：80 DEG C of initial temperature, 250 DEG C are raised to 30 DEG C/min speed, keeps 2min；
Mass spectrometry parameters：230 DEG C of ion source temperature；150 DEG C of quadrupole rod；250 DEG C of transmission line temperature；Solvent delay 2min；It is double
Channel scan：Scan scanning ranges, 10~200m/z, SIM scanning, quota ion 99, with reference to ion 98,44,70.
A kind of assay method of electrodes of lithium-ion batteries NMP contents of the present embodiment, it comprises the following steps：
1) prepared by prepare liquid：
The pole piece to be measured dried 6 hours after coating is cut into about 1cm × 1cm sizes, respectively weigh 3 it is parallel treat test sample in
Ultrasonic sample bottle, quality are respectively 0.5168g, 0.5507g, 0.6008g；
Toward the ethanol equipped with accurate addition 25mL in the sample bottle for treating test sample, tightened with the bottle cap with silica gel sealing pad,
Sample bottle is placed in into ultrasound in ultrasonic washing instrument to be extracted within 1 hour, ultrasonic power 400W；
After the completion of ultrasound, sample bottle is moved on into vent cabinet, stands, be cooled to room temperature, with 0.45 μm of the organic filter in aperture
Core extracted by filtration liquid obtains prepare liquid into GC-MS sample injection bottles.
2) standard liquid is prepared：
Precise 0.0977g purity is 99.9% NMP, constant volume 100mL, obtains 976.0mg/L storing solution；
Using diluting step by step, it is respectively 0.4880mg/L, 0.9760mg/L, 1.9520mg/ that storing solution is configured into concentration
L, 4.8800mg/L, 9.7600mg/L Working Standard Solution.
3) draw standard curve and treat that test sample is tested：
Working Standard Solution is tested with GC-MS, draws standard curve；
Prepare liquid is tested with GC-MS, according to the standard curve of drafting, the content of NMP in prepare liquid can be measured, surveyed
Three parallel NMP contents for treating test sample are respectively 0.7506mg/L, 0.8394mg/L, 0.8406mg/L, finally can by following formula
Obtain the content W of NMP in pole piece；
Wherein：W be pole piece in NMP content, unit mg/kg；
C is the NMP concentration of the prepare liquid measured, unit mg/L；
V is constant volume, unit mL；
M be weigh pole piece quality, unit g.
The measurement result that above three is parallel to treat test sample is as shown in table 2.
The pole piece NMP assay results of the present embodiment of table 2
From embodiment 1 and the measurement result of embodiment 2, the relative standard deviation of two embodiment parallel determinations
(RSD) 5% is below, illustrates that the assay method of NMP contents in battery pole piece of the present invention is reproducible, with a high credibility, Neng Gouyou
Effect meets currently to the monitoring requirements of NMP contents in electrodes of lithium-ion batteries.
The announcement and teaching of book according to the above description, those skilled in the art in the invention can also be to above-mentioned embodiment party
Formula is changed and changed.Therefore, the invention is not limited in above-mentioned embodiment, every those skilled in the art exist
Made any conspicuously improved, replacement or modification belong to protection scope of the present invention on the basis of the present invention.This
Outside, although having used some specific terms in this specification, these terms merely for convenience of description, not to the present invention
Form any restrictions.
Claims (7)
- A kind of 1. assay method of electrodes of lithium-ion batteries NMP contents, it is characterised in that：Comprise the following steps：Step 1), sample pre-treatments：A pole piece to be measured is taken, it is A × Acm to cut out size in the NMP rich regions of pole piece to be measured Sample；Wherein, A is positive integer；Step 2), treat that test sample extracts：0.1~2g of sample of step 1) processing is weighed, and is put into sample bottle, addition 10~ 50mL Extraction solvents, with instrument 0.5~2h of ultrasonic extraction is cleaned by ultrasonic, after the completion of ultrasonic, stand, room temperature is cooled to, with organic mistake Test sample is treated in filter element filtering extract to sample injection bottle, acquisition；Step 3), standard liquid are prepared：Using diluting step by step, pure material NMP is diluted to the work mark of at least five various concentrations Quasi- solution, concentration range are 0.1~10mg/L；Step 4), draw standard curve：The Working Standard Solution of step 3) is tested with gas chromatograph-mass spectrometer (GC-MS), Obtain standard curve；Step 5), treat that test sample is tested：Step 2) is treated that test sample is tested with gas chromatograph-mass spectrometer (GC-MS), according to step 4) standard curve obtained, measures the content for treating NMP in test sample.
- 2. the assay method of electrodes of lithium-ion batteries NMP contents according to claim 1, it is characterised in that：NMP in pole piece Content W be：Wherein, the c NMP concentration of test sample that is that what is measured treat, V is constant volume, and m is the pole piece matter weighed Amount.
- 3. the assay method of electrodes of lithium-ion batteries NMP contents according to claim 1, it is characterised in that：In step 1) The NMP rich regions are the intermediate region of pole piece.
- 4. the assay method of electrodes of lithium-ion batteries NMP contents according to claim 1, it is characterised in that：In step 1) The pole piece to be measured is the pole piece of 2~6h of drying after coating.
- 5. the assay method of electrodes of lithium-ion batteries NMP contents according to claim 1, it is characterised in that：In step 2) The Extraction solvent is acetone, ethanol, methanol, n-butanol, methanol and ethanol, the tert-butyl alcohol, phenol, acetonitrile, ether, isopropyl ether, oil At least one of ether, tetrahydrofuran, chloroform, ethyl acetate, butyl acetate.
- 6. the assay method of electrodes of lithium-ion batteries NMP contents according to claim 1, it is characterised in that：In step 2) The power for being cleaned by ultrasonic instrument is set to 300~500W.
- 7. the assay method of electrodes of lithium-ion batteries NMP contents according to claim 1, it is characterised in that：In step 2) The pore size of the organic filter core is 0.2~0.8 μm.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109752225A (en) * | 2018-12-29 | 2019-05-14 | 上海微谱化工技术服务有限公司 | A kind of cathode of lithium battery binding material qualitative-and-quantitative method |
| CN113311086A (en) * | 2021-05-26 | 2021-08-27 | 湖北亿纬动力有限公司 | Method for detecting residual NMP in pole piece |
| CN113804799A (en) * | 2021-10-25 | 2021-12-17 | 合肥国轩高科动力能源有限公司 | Pretreatment method and method for testing NMP content in lithium ion battery pole piece |
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| CN113311086A (en) * | 2021-05-26 | 2021-08-27 | 湖北亿纬动力有限公司 | Method for detecting residual NMP in pole piece |
| CN113804799A (en) * | 2021-10-25 | 2021-12-17 | 合肥国轩高科动力能源有限公司 | Pretreatment method and method for testing NMP content in lithium ion battery pole piece |
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Application publication date: 20180406 |