A method for determining easily decomposable substances in organic electrolytes
Patent Information
- Application Number
- CN202510144530.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-10
- Publication Date
- 2026-08-11
AI Technical Summary
[0004]本发明针对现有技术中的问题，本发明提供了一种测定有机电解液中易分解物质的方法，利用色质谱联用技术结合H-NMR，解决了色质谱联用技术难以对易分解物质定性定量，并避免了H-NMR测试时，内标法对待测有机电解液的影响，获得了一种简单、准确的测量方式
[0031]本发明通过色质谱联用技术结合H-NMR，有效解决了传统色质谱联用技术在对易分解物质(如TMSB或/和TMSP)进行定性和定量时所面临的困难，通过这种结合方式，能够确保在有机电解液复杂背景下，准确识别易分解物质的信号，并依据H-NMR中积分面积与物质浓度成比例，实现了对易分解物质的精确定量，为有机电解液中易分解物质的检测提供了一种全新的解决方案。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery electrolyte component detection and analysis, specifically relating to a method for determining easily decomposable substances in organic electrolytes. Technical Background
[0002] In recent years, with the gradual development of the battery industry, novel additives such as tris(trimethylsiloxy)boron (TMSB) and tris(trimethylsilyl)phosphate (TMSP) have been increasingly widely used in the formulation of organic electrolytes for lithium batteries. However, additives such as TMSP and TMSB often have reactive chemical properties and will rapidly decompose when measured by gas chromatography-mass spectrometry (GC-MS) or ion chromatography (IC), causing characteristic peaks to gradually decrease over time, or even disappear altogether. This makes it difficult to obtain only fragmentary information in practical tests, and to perform qualitative and quantitative analysis of these easily decomposable substances using simple GC-MS or IC tests.
[0003] Therefore, 1H nuclear magnetic resonance (1H-NMR) spectroscopy has come to the attention of researchers. Compared to GC-MS, the non-destructive nature of H-NMR testing effectively avoids the decomposition of TMSP and TMSB during the testing process, thus effectively solving the problem of qualitative analysis difficulties in GC-MS. However, H-NMR testing also has its drawbacks. To improve the accuracy of the test, the internal standard method is often used in H-NMR testing. However, although the internal standard method can provide more accurate and reliable quantitative results to a certain extent, the introduction of an additional internal standard undoubtedly increases the risk of contamination for organic electrolytes with complex compositions, thus affecting the accuracy of the test results. Therefore, how to effectively utilize H-NMR testing to detect TMSP and TMSB results while avoiding the influence of the internal standard on the composition of organic electrolytes and improving the accuracy of the test has become a current research challenge. Summary of the Invention
[0004] This invention addresses the problems in the prior art by providing a method for determining easily decomposable substances in organic electrolytes. It utilizes chromatography-mass spectrometry combined with H-NMR, which solves the problem that chromatography-mass spectrometry is difficult to use for qualitative and quantitative analysis of easily decomposable substances, and avoids the influence of the internal standard method on the organic electrolyte being tested during H-NMR testing, thus obtaining a simple and accurate measurement method.
[0005] This invention provides a method for determining easily decomposable substances in organic electrolytes, comprising the following steps:
[0006] S1: The organic electrolyte to be tested is tested by chromatography-mass spectrometry to determine the types and proton status of stable substances in the organic electrolyte to be tested, establish the standard concentration curve of stable substances and calculate the content of stable substances.
[0007] S2: Peak position marker; specifically includes:
[0008] S201: First, add a deuterated reagent to the organic electrolyte to be tested, and then test the organic electrolyte to be tested by nuclear magnetic resonance hydrogen spectrum, and mark the peak positions of each substance in the organic electrolyte to be tested;
[0009] Easily decomposable substances and stable substances were added to deuterated reagents to obtain easily decomposable substance standards and stable substance standards, respectively. The easily decomposable substance standards and stable substance standards were tested by nuclear magnetic resonance hydrogen spectroscopy, and the elution positions of the easily decomposable substance standards and stable substance standards were marked.
[0010] S202: Mark the peak positions of easily decomposable substances in the organic electrolyte to be tested based on the peak positions of the easily decomposable substance standard sample.
[0011] S3: Based on the content of stable substances and proton status, and combined with the integrated area of each substance in the organic electrolyte to be tested in the proton NMR spectrum test in S2, the peak area ratio is calculated to obtain the content of easily decomposed substances.
[0012] The easily decomposable substances are selected from alkylsilane compounds.
[0013] As a further option, the organic electrolyte to be tested may or may not contain electrolyte salts.
[0014] As a further option, the alkylsilyl compound is selected from trimethylsilyl compounds.
[0015] As a further option, the trimethylsilyl compound is selected from any one of trimethylsilyl ester additives, trimethylsilyl silazane additives, and trimethylsilyl silane additives.
[0016] As a further option, the trimethylsilyl ester additive is selected from trimethylsilyl phosphate additives, trimethylsilyl phosphite additives, trimethylsilyl boronic acid ester additives, trimethylsilyl carbonate additives, and trimethylsilyl sulfonate additives.
[0017] As a further option, the trimethylsilyl silazane additive is selected from hexamethyldisilazane.
[0018] As a further option, the trimethylsilane-based silane additive is selected from vinyltrimethylsilane.
[0019] As a further option, in S1, the chromatography-coupling technique is selected from any one or more of gas chromatographs, GC-MS, IC, and mass spectrometers.
[0020] As a further option, in S1, when testing the organic electrolyte to be tested using chromatography-coupled techniques, the dilution factor of the organic electrolyte to be tested is selected from 10 to 100 times.
[0021] As a further step, in S1, the diluent for diluting the organic electrolyte to be tested is selected from any one of acetonitrile, methanol, ethyl acetate, and ethylene glycol dimethyl ether.
[0022] As a further option, in S1, the standard concentration curve of the stable substance is established and the content of the stable substance is calculated, which can be selected from either the external standard method or the internal standard method.
[0023] As a further option, the coefficient of determination R of the standard concentration curves established by the external standard method and the internal standard method is... 2 ≥0.99.
[0024] As a further option, in the internal standard method, the internal standard is not limited in principle. Technicians can select substances whose peaks do not overlap with those in the chromatographic mass spectrometry technique, such as any one of ethyl acetate, ethylene glycol dimethyl ether, adiponitrile, and hexanetrionitrile.
[0025] As a further option, the proton NMR spectrum is selected from liquid proton NMR spectrum.
[0026] As a further option, in S201, the deuterated reagent is selected from any one of deuterated chloroform, deuterated dimethyl sulfoxide, and deuterated acetone.
[0027] As a further option, in S201, the volume ratio of the organic electrolyte to be tested to the deuterated reagent is selected from (1-2):(50-120).
[0028] As a further step, in S201, 5-15 mg of the easily decomposable substance is dissolved in 0.5-1 mL of deuterated reagent.
[0029] As a further solution, in step S3, the formula for calculating the peak area ratio is as follows: A x·y·i =[(N y / J y ×M y ) / (N x / J x ×M x )]×Ax Where x represents a stable substance in the organic electrolyte to be tested, wherein the hydrogen proton elution position of the stable substance does not overlap with the absorption peak of any other substance; y represents an easily decomposable substance; A represents the substance content; N represents the peak integral; J represents the number of hydrogen atoms at the elution position; M represents the relative molecular weight; n represents the number of any stable substances in the organic electrolyte to be tested, i≤n; A x·y·i This represents the content of y calculated from the i-th substance x.
[0030] Compared with the prior art, the present invention has at least the following beneficial effects:
[0031] This invention effectively solves the difficulties faced by traditional chromatographic mass spectrometry (GC-MS) techniques in qualitative and quantitative analysis of easily decomposable substances (such as TMSB and / or TMSP) by combining GC-MS with H-NMR. This combination ensures accurate identification of signals of easily decomposable substances in complex organic electrolytes and achieves precise quantification of these substances based on the proportionality between the integral area and the concentration in H-NMR. This provides a novel solution for the detection of easily decomposable substances in organic electrolytes.
[0032] Furthermore, this invention avoids the influence of internal standard methods on the composition and physicochemical properties of organic electrolytes. By using chromatography-mass spectrometry to quantify measurable substances in organic electrolytes, the reliance on internal standard methods in traditional testing is avoided, thus preventing potential biases introduced by internal standard methods and making the analytical results more reliable and accurate. Attached Figure Description
[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0034] Figure 1 Here is the gas chromatogram of Example 1;
[0035] Figure 2 The mass spectrum of Example 1;
[0036] Figure 3 The IC test results are for Example 1;
[0037] Figure 4 The standard concentration curve of fluoroethylene carbonate (FEC) was obtained by GC-MS in Example 1.
[0038] Figure 5 The above are the H-NMR test results of the organic electrolyte to be tested in Example 1;
[0039] Figure 6 The above are the H-NMR test results of the TMSP standard sample in Example 1;
[0040] Figure 7 The results of H-NMR testing of the TMSB standard sample were obtained using the test conditions of Example 1;
[0041] Figure 8 The results are H-NMR measurements of the FEC standard sample obtained under the test conditions of Example 1. Detailed Implementation
[0042] For ease of understanding, the present invention will be described more fully below, and embodiments of the present invention will be given, but this does not limit the scope of the present invention.
[0043] The following are descriptions of terms or words, and unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains.
[0044] In this article, the term "stable substance" refers to substances in organic electrolytes that can be accurately and clearly qualitatively and quantitatively identified using mass spectrometry.
[0045] In this article, the term "any substance" refers to all substances in the organic electrolyte that can be measured by chromatography-mass spectrometry and H-NMR, and these substances may have overlapping absorption peaks.
[0046] This invention provides a method for determining easily decomposable substances in organic electrolytes, comprising the following steps:
[0047] S1: The organic electrolyte to be tested is tested by chromatography-mass spectrometry to determine the types and proton status of stable substances in the organic electrolyte to be tested, establish the standard concentration curve of stable substances and calculate the content of stable substances.
[0048] S2: Peak position marker; specifically includes:
[0049] S201: First, add a deuterated reagent to the organic electrolyte to be tested, and then test the organic electrolyte to be tested by nuclear magnetic resonance hydrogen spectrum, and mark the peak positions of each substance in the organic electrolyte to be tested;
[0050] Easily decomposable substances and stable substances were added to deuterated reagents to obtain easily decomposable substance standards and stable substance standards, respectively. The easily decomposable substance standards and stable substance standards were tested by nuclear magnetic resonance hydrogen spectroscopy, and the elution positions of the easily decomposable substance standards and stable substance standards were marked.
[0051] S202: Mark the peak positions of easily decomposable substances in the organic electrolyte to be tested based on the peak positions of the easily decomposable substance standard sample.
[0052] S3: Based on the content of stable substances and proton status, and combined with the integrated area of each substance in the organic electrolyte to be tested in the proton NMR spectrum test in S2, the peak area ratio is calculated to obtain the content of easily decomposed substances.
[0053] Among them, easily decomposable substances are selected from compounds containing alkylsilane groups.
[0054] In H-NMR testing, for a given proton, its integral is proportional to its molar concentration. Therefore, in traditional testing, the internal standard method is often used: adding a known concentration of internal standard to the sample and comparing the integral values of the sample peak and the internal standard peak to calculate the sample purity or concentration for quantitative analysis. However, quantification using the internal standard method requires the introduction of an additional internal standard substance, which undoubtedly poses a risk of contamination for complex organic electrolytes. Therefore, this proposal suggests a method that first uses chromatography-mass spectrometry (GC-MS) to test the organic electrolyte to determine the types of stable substances. The method involves determining the proton composition by identifying the types of substances, then calculating the content of these substances in the organic electrolyte based on standard concentration curves. Subsequently, after H-NMR testing, the concentration of easily decomposable substances is determined by utilizing the proportionality between the proton integral and molar concentration in H-NMR, thus achieving precise quantification of easily decomposable substances. This method cleverly utilizes the characteristic of mass spectrometry (MS / MS) to accurately quantify stable substances, combined with the principle of NMR quantification. This achieves accurate testing of easily decomposable substances while avoiding the influence of internal standard methods on the organic electrolyte, thereby providing an accurate detection method for TMSB and / or TMSP.
[0055] As a further option, the alkylsilyl compound is selected from trimethylsilyl compounds.
[0056] As a further option, the trimethylsilyl compound is selected from any one of trimethylsilyl ester additives, trimethylsilyl silazane additives, and trimethylsilyl silane additives.
[0057] As a further option, the trimethylsilyl ester additive is selected from trimethylsilyl phosphate additives, trimethylsilyl phosphite additives, trimethylsilyl boronic acid ester additives, trimethylsilyl carbonate additives, and trimethylsilyl sulfonate additives.
[0058] As a further option, the trimethylsilyl silazane additive is selected from hexamethyldisilazane.
[0059] As a further option, the trimethylsilane-based silane additive is selected from vinyltrimethylsilane.
[0060] As a further option, the organic electrolyte to be tested may or may not contain electrolyte salts.
[0061] As some parameters for reference, in S1, the chromatography coupling technology is not limited in principle, and technicians can choose any one or more of gas chromatographs, GC-MS, IC, and mass spectrometers according to their needs.
[0062] As some reference parameters, the chromatography-coupling techniques selected are GC-MS and IC. GC-MS can obtain solvent information, while IC can clearly measure the information of electrolyte salts in the organic electrolyte to be tested, thereby achieving more accurate qualitative and quantitative analysis of stable substances in the organic electrolyte to be tested.
[0063] As some reference parameters, in S1, when testing the organic electrolyte by chromatography-coupled techniques, the dilution factor of the organic electrolyte to be tested is selected from 10 to 100 times.
[0064] As some parameters for reference, in S1, the diluent for diluting the organic electrolyte to be tested is selected from any one of acetonitrile, methanol, ethyl acetate, and ethylene glycol dimethyl ether.
[0065] As some reference parameters, in S1, the standard concentration curve of the stable substance is established and the content of the stable substance is calculated, which can be selected from either the external standard method or the internal standard method.
[0066] As some parameters for reference, the coefficient of determination R of the standard concentration curves established by the external standard method and the internal standard method is... 2 ≥0.99. Coefficient of determination R 2 A value ≥0.99 helps ensure the accuracy of the standard concentration curve and improves quantitative precision.
[0067] As some parameters for reference, the internal standard in the internal standard method is not limited in principle. Technicians can choose substances that do not overlap with the peaks in the chromatographic mass spectrometry technique, such as any one of ethyl acetate, ethylene glycol dimethyl ether, adiponitrile, and hexanetrionitrile.
[0068] As some reference parameters, the method for establishing the standard concentration curve of the stable substance in S1 is the external standard method. By establishing the standard concentration curve through the external standard method, the influence of the internal standard on the organic electrolyte under test is avoided, thereby optimizing the test accuracy.
[0069] As some parameters for reference, the proton NMR spectrum is selected from liquid proton NMR spectrum.
[0070] As some parameters for reference, in S201, the deuterated reagent is selected from any one of deuterated chloroform, deuterated dimethyl sulfoxide, and deuterated acetone.
[0071] As some reference parameters, in S201, the volume ratio of the organic electrolyte to the deuterated reagent is selected from (1-2):(50-120). A suitable concentration of the organic electrolyte helps to obtain clearer and more accurate peak positions and integrated areas. In this scheme, setting the volume ratio of the organic electrolyte to the deuterated reagent to (1-2):(50-120) helps to better dilute the organic electrolyte, thereby obtaining a clearer H-NMR spectrum.
[0072] As some reference parameters, in S201, 5-15 mg of easily decomposable substances dissolved in 0.5-1 mL of deuterated reagent helps to obtain more accurate test results for TMSP and TMSB standards. Different structures of TMSP and TMSB will show different chemical shifts in H-NMR tests; for example... Figure 6-7 ,in, Figure 7 The 0.08 ppm peak is attributed to TMSB. Figure 6 The 0.17 ppm peak is attributed to TMSP. Because phosphorus atoms in TMSP have a deshielding effect on neighboring hydrogen atoms, the chemical shift of hydrogen atoms shifts to a lower field. In contrast, boron atoms in TMSB have a weaker shielding effect on neighboring hydrogen atoms, so the chemical shift of these hydrogen atoms may be closer to the 0 ppm position.
[0073] As some parameters for reference, the formula for calculating the peak area ratio in S3 is as follows: Where x represents a stable substance in the organic electrolyte to be tested, wherein the hydrogen proton elution position of the stable substance does not overlap with the absorption peak of any other substance; y represents an easily decomposable substance; A represents the substance content; N represents the peak integral; J represents the number of hydrogen atoms at the elution position; M represents the relative molecular weight; n represents the number of any stable substances in the organic electrolyte to be tested, i≤n; A x·y·i This represents the content of y calculated from the i-th substance x.
[0074] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application and do not represent all possible embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0075] The chemical raw materials used in the following examples and comparative examples are all prior art and were obtained commercially. The experimental apparatus and testing equipment used in the following examples and comparative examples are all conventional equipment in the art, and there are no special requirements or limitations.
[0076] Example 1: Testing of TMSP
[0077] The organic electrolyte containing TMSP was prepared for testing. The composition of the organic electrolyte is shown in Table 1.
[0078] Table 1
[0079]
[0080] The GC-MS model is Agilent 7890B+5977B;
[0081] The IC model is Metrohm 930;
[0082] The NMR sensor is a Bruker AVANCE NEO 400M NMR.
[0083] S1: Take 200 μL of organic electrolyte, dilute it 100 times with acetonitrile, and perform GC-MS and IC tests. The GC-MS test conditions are as follows: column temperature program: initial temperature 40℃, hold for 3 minutes, then increase the temperature to 80℃ at a rate of 10℃ / min, then increase the temperature to 160℃ at a rate of 20℃ / min and hold for 7 minutes. Injector temperature: 250℃.
[0084] Mass spectrometry testing conditions: mass-to-charge ratio scanning range of 35-450u, ion source 280℃, quadrupole 150℃.
[0085] The IC test conditions were as follows: column temperature: 35℃, isocratic elution with carbonate (sodium carbonate / sodium bicarbonate)-acetonitrile system (70:30, v / v) as the eluent, and flow rate: 1.0 mL / min.
[0086] A standard concentration curve for stable substances was established using the external standard method.
[0087] GC-MS test results can be found Figure 1-2 ,Depend on Figure 1-2 It can be observed that DMC, EMC, VC, FEC, EV, PC, DTD and other substances were detected in the tested organic electrolyte. No obvious structural information of TMSP was found. Trimethylsilanol was only found at 2.03 min, and its classification could not be inferred.
[0088] IC test results are as follows Figure 3 As shown, Figure 3 The presence of substances such as LiPO2F2, LiBF4, LiODFB, LiPF6, and LiFSI can be clearly observed.
[0089] Establish a standard curve of substance concentration versus GCMS peak response value to determine the content of stable substances in organic electrolyte;
[0090] like Figure 4The equation for the standard concentration curve of fluoroethylene carbonate (FEC) is y = 830.376410x + 73.122417, R 2 =0.9997.
[0091] The concentration of FEC was calculated by substituting the obtained peak response value of FEC in GCMS detection into the above formula. x represents the test result (%), C represents the sample concentration calculated by the external standard curve method (μg / mL), V represents the final volume (mL), F represents the dilution factor, and m represents the sample weight (mg).
[0092] The peak response value of FEC detected in gas chromatography was 22705. Substituting this value into the external standard curve equation above, the calculated FEC concentration was 27.2549 μg / mL. Based on the pretreatment FEC volume of 10 mL, a dilution factor of 10, and a sample amount of 250.9 mg, the calculated FEC content was 1.09%.
[0093] S2: Sample of the organic electrolyte to be tested... 1 H-NMR test.
[0094] S201: Dissolve 15 μL of the organic electrolyte to be tested in 1 mL of deuterated dimethyl sulfoxide, and then perform H-NMR analysis. The test results are shown in [Figure 1]. Figure 5 ;
[0095] 10 mg of FEC was dissolved in 1 mL of deuterated deuterated chloroform, followed by H-NMR analysis. The results are shown in [Figure number missing]. Figure 8 ;
[0096] 10 mg of TMSP was dissolved in 1 mL of deuterated deuterated chloroform, followed by H-NMR analysis. The results are shown in [Figure number missing]. Figure 6 ;
[0097] H-NMR testing procedure: Select the standard experimental name PROTON (hydrogen spectrum), and perform 16 scans.
[0098] according to Figure 6 Peak position of TMSP standard Figure 5 In the test, the elution position of TMSP in the organic electrolyte can be observed. Figure 5 In the figure, the peak at 0.18 ppm is attributed to TMSP, and the peak at the chemical shift of 0.18 ppm is also attributed to TMSP.
[0099] S3: Calculate the ratio between the peak areas of the relevant substances quantified by the external standard method obtained in S1 and the TMSP peak area in the proton spectrum, according to the formula... Where x represents stable substances in the organic electrolyte to be tested, y represents easily decomposable substances, A represents the substance content, N represents the peak integral, J represents the number of hydrogen atoms at the peak position, M represents the relative molecular weight, and n represents the number of any stable substances in the organic electrolyte to be tested, i≤n, A x·y·i This represents the content of y calculated from the i-th substance x.
[0100] Depend on Figure 5 It can be seen that the FEC peak integral is 1; the number of hydrogen protons at the FEC peak is 1; the relative molecular mass of FEC is 106.05; the TMSP peak integral is 1.46; the number of hydrogen protons at the TMSP peak is 27; and the relative molecular mass of TMSP is 314.54.
[0101] The VC content was 2.00%, the VC peak integral was 4.64, the number of hydrogen protons at the VC peak was 2, the relative molecular mass of VC was 86.05, the TMSP peak integral was 1.46, the number of hydrogen protons at the TMSP peak was 27, and the relative molecular mass of TMSP was 314.54.
[0102] A FEC·TMSP·1 = [(1.46 / 27×314.54) / (1 / 1×106.05)]×1.09% = 0.1748%;
[0103] A VC·TMSP·2 = [(1.46 / 27×314.54) / (4.64 / 2×86.05)]×2.00% = 0.1704%;
[0104] Ay=(A FEC·TMSP·1 +A VC·TMSP·2 ) / 2 = 0.1726%.
[0105] The average TMSP content obtained through this method is 0.1726%, which is close to the actual TMSP addition of 0.18%. Based on the above technical solution, this invention provides a method for testing TMSB or TMSP in lithium-ion battery organic electrolytes. This method is based on GC-MS, IC, and NMR detection. NMR detection technology is added to compensate for the shortcomings of GC-MS and IC in detecting organic electrolytes. Based on the above embodiments, the identification and testing method for TMSB and TMSP in lithium-ion battery organic electrolytes provided by this invention is easy to implement, can reliably obtain the TMSP and TMSB content in the test sample, and facilitates the analysis of organic electrolytes.
[0106] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions, and variations to the above embodiments within the scope of the present invention. Furthermore, without contradiction, those skilled in the art can combine and integrate different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
Claims
1. A method for measuring a decomposable substance in an organic electrolyte, characterized by, Includes the following steps: S1: The organic electrolyte to be tested is tested by chromatography-mass spectrometry to determine the types and proton status of stable substances in the organic electrolyte to be tested, establish the standard concentration curve of stable substances and calculate the content of stable substances. S2: Peak position marker; specifically includes: S201: First, add a deuterated reagent to the organic electrolyte to be tested, and then test the organic electrolyte to be tested by nuclear magnetic resonance hydrogen spectrum, and mark the peak positions of each substance in the organic electrolyte to be tested; The peak positions of easily decomposable and stable substances were determined by 1H NMR spectroscopy, and the peak positions of the easily decomposable and stable substances were marked. S202: Mark the peak positions of easily decomposable substances in the organic electrolyte to be tested based on the peak positions of the easily decomposable substance standard sample. S3: Based on the content of stable substances and proton status, and combined with the integrated area of each substance in the organic electrolyte to be tested in the proton NMR spectrum test in S2, the peak area ratio is calculated to obtain the content of easily decomposed substances. The easily decomposable substances are selected from alkylsilane compounds.
2. The method of measuring a decomposable substance in an organic electrolyte according to claim 1, characterized by, In S1, the chromatography-coupled techniques are selected from any one or more of gas chromatographs, gas chromatography-mass spectrometry, ion chromatography, and mass spectrometry. Preferably, the alkylsilyl compound is selected from trimethylsilyl compounds; Preferably, the trimethylsilyl compound is selected from any one of trimethylsilyl ester additives, trimethylsilyl silazane additives, and trimethylsilyl silane additives; Preferably, the trimethylsilyl ester additive is selected from trimethylsilyl phosphate additives, trimethylsilyl phosphite additives, trimethylsilyl borate additives, trimethylsilyl carbonate additives, and trimethylsilyl sulfonate additives. Preferably, the trimethylsilyl silazane additive is selected from hexamethyldisilazane; Preferably, the trimethylsilane-based silane additive is selected from vinyltrimethylsilane.
3. The method of measuring a decomposable substance in an organic electrolyte according to claim 1, characterized by, In S1, when testing the organic electrolyte using chromatography-coupled techniques, the dilution factor of the organic electrolyte to be tested is selected from 10 to 100 times.
4. The method of measuring a decomposable substance in an organic electrolyte according to claim 3, characterized by, In S1, the diluent for diluting the organic electrolyte to be tested is selected from any one of acetonitrile, methanol, ethyl acetate, and ethylene glycol dimethyl ether.
5. The method of measuring a decomposable substance in an organic electrolyte according to claim 1, characterized by, In S1, the standard concentration curve of the stable substance is established and the content of the stable substance is calculated by selecting either the external standard method or the internal standard method. The standard concentration curve established by the external standard method and the internal standard method has a determination coefficient R 2 ≥0.99; In the internal standard method, the internal standard is selected from substances whose peaks do not overlap with those of the substances in the sample, including any one of ethyl acetate, ethylene glycol dimethyl ether, adiponitrile, and hexanetrionitrile.
6. The method of measuring a decomposable substance in an organic electrolyte according to claim 1, characterized by, In S201, the deuterated reagent is selected from any one of deuterated chloroform, deuterated dimethyl sulfoxide, and deuterated acetone.
7. The method for determining easily decomposable substances in organic electrolytes according to claim 1, characterized in that, In S201, the volume ratio of the organic electrolyte to be tested to the deuterated reagent is selected from (1-2):(50-120).
8. The method for determining easily decomposable substances in organic electrolytes according to claim 1, characterized in that, In S201, 5-15 mg of easily decomposable substances are dissolved in 0.5-1 mL of deuterated reagent.
9. The method of measuring a decomposable substance in an organic electrolyte according to claim 1, characterized by, In S3, the formula for calculating the peak area ratio is as follows: Where x represents a stable substance in the organic electrolyte to be tested, wherein the hydrogen proton elution position of the stable substance does not overlap with the absorption peak of any other substance; y represents an easily decomposable substance; A represents the substance content; N represents the peak integral; J represents the number of hydrogen atoms at the elution position; M represents the relative molecular weight; and n represents the number of any stable substances in the organic electrolyte to be tested, i≤n, A x·y·i This represents the content of y calculated from the i-th substance x.