KR20230071743A - Analysis method of residual lithium compound present in cathode active material - Google Patents
Analysis method of residual lithium compound present in cathode active material Download PDFInfo
- Publication number
- KR20230071743A KR20230071743A KR1020220151533A KR20220151533A KR20230071743A KR 20230071743 A KR20230071743 A KR 20230071743A KR 1020220151533 A KR1020220151533 A KR 1020220151533A KR 20220151533 A KR20220151533 A KR 20220151533A KR 20230071743 A KR20230071743 A KR 20230071743A
- Authority
- KR
- South Korea
- Prior art keywords
- content
- active material
- cathode active
- sample
- analysis
- Prior art date
Links
- 239000006182 cathode active material Substances 0.000 title claims abstract description 54
- 150000002642 lithium compounds Chemical class 0.000 title claims abstract description 15
- 238000004458 analytical method Methods 0.000 title claims description 46
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims abstract description 92
- 238000000034 method Methods 0.000 claims abstract description 22
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 20
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 20
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 20
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000001257 hydrogen Substances 0.000 claims abstract description 15
- 238000005259 measurement Methods 0.000 claims abstract description 6
- YQCIWBXEVYWRCW-UHFFFAOYSA-N methane;sulfane Chemical compound C.S YQCIWBXEVYWRCW-UHFFFAOYSA-N 0.000 claims abstract description 5
- 238000009616 inductively coupled plasma Methods 0.000 claims abstract description 3
- 230000003287 optical effect Effects 0.000 claims abstract description 3
- 229910052744 lithium Inorganic materials 0.000 claims description 48
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 44
- 229910018068 Li 2 O Inorganic materials 0.000 claims description 35
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 13
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 12
- 239000011593 sulfur Substances 0.000 claims description 12
- 229910021642 ultra pure water Inorganic materials 0.000 claims description 8
- 239000012498 ultrapure water Substances 0.000 claims description 8
- 239000007774 positive electrode material Substances 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 4
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 3
- OLBVUFHMDRJKTK-UHFFFAOYSA-N [N].[O] Chemical compound [N].[O] OLBVUFHMDRJKTK-UHFFFAOYSA-N 0.000 claims description 3
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 claims description 3
- 238000010828 elution Methods 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 150000002431 hydrogen Chemical class 0.000 claims 1
- 239000007772 electrode material Substances 0.000 abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 abstract description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 3
- 239000001301 oxygen Substances 0.000 abstract description 3
- 239000000523 sample Substances 0.000 description 34
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 6
- 238000004448 titration Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000011149 active material Substances 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 239000000706 filtrate Substances 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910001416 lithium ion Inorganic materials 0.000 description 4
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Chemical compound [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000002775 capsule Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 2
- 229910052808 lithium carbonate Inorganic materials 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000004445 quantitative analysis Methods 0.000 description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910011281 LiCoPO 4 Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
- 229910013553 LiNO Inorganic materials 0.000 description 1
- 229910013716 LiNi Inorganic materials 0.000 description 1
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 1
- -1 LiOH Chemical class 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen(.) Chemical compound [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 238000001139 pH measurement Methods 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 239000000550 preparative sample Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000012488 sample solution Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/59—Transmissivity
- G01N21/61—Non-dispersive gas analysers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
- G01N21/73—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited using plasma burners or torches
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Pathology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Electrochemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Plasma & Fusion (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
본 발명은 리튬 이차전지용 양극활물질에서 충방전에 관여하지 않는 잔류 리튬 화합물을 분석하는 방법에 관한 것이다.The present invention relates to a method for analyzing residual lithium compounds not involved in charging and discharging in a cathode active material for a lithium secondary battery.
리튬 이차전지는 일반적으로 리튬 이온을 삽입/방출할 수 있는 전극활물질을 포함하는 양극과 음극, 상기 두 전극을 분리하기 위한 분리막으로 구성된 전극 조립체에 리튬 이온의 전달 매질인 전해액이 함침되어 있는 구조로 이루어져 있으며, 리튬 이온이 전해액을 통해 음극과 양극 사이를 오가며 전지의 충전과 방전이 일어난다. 상기 전극은 포일(foil) 형태의 집전체에 활물질, 도전재, 바인더 등의 전극재를 함유하는 슬러리를 코팅하여 건조하고, 압연(pressing)의 공정을 거쳐 활물질층을 형성함으로써 제조되는 것이 일반적이다.Lithium secondary batteries generally have a structure in which an electrolyte solution, a transfer medium of lithium ions, is impregnated with an electrode assembly composed of a positive electrode and a negative electrode containing electrode active materials capable of intercalating/extracting lithium ions, and a separator for separating the two electrodes. The battery is charged and discharged as lithium ions move between the negative electrode and the positive electrode through the electrolyte. The electrode is generally manufactured by coating a foil-shaped current collector with a slurry containing an electrode material such as an active material, a conductive material, and a binder, drying it, and forming an active material layer through a pressing process. .
이러한 이차전지의 성능은 양극, 음극, 분리막 및 전해질의 구성요소, 상기 각 구성요소의 조성, 그에 의한 충방전 특성 등 여러 인자들에 의해서 영향을 받는다. 특히, 양극활물질의 제조 과정에서 생성된 리튬 부산물, 즉 양극활물질에 존재하지만 충방전에 관여하지 않는 잔류 리튬 화합물은 양극 성능을 저해할 수 있으므로, 이의 분석은 전지 성능 평가에 중요하다. The performance of these secondary batteries is influenced by various factors, such as the components of a positive electrode, a negative electrode, a separator, and an electrolyte, the composition of each component, and charge/discharge characteristics thereof. In particular, since lithium by-products generated during the manufacturing process of the cathode active material, that is, residual lithium compounds present in the cathode active material but not involved in charging and discharging may impair cathode performance, its analysis is important for battery performance evaluation.
일반적으로 LiOH, Li2CO3, Li2SO4 및 Li2O를 양극활물질의 4대 잔류 화합물로 보고 있으며, 기존에는 이들 잔류 성분들을 분석하기 위해 양극활물질 시료를 물에 교반시켜 잔류 화합물을 용출한 후 여과액에 대해 pH를 측정하는 습식 방식이 수행되었다. In general, LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O are regarded as the four major residual compounds of the cathode active material, and in order to analyze these residual components, in the past, a cathode active material sample was stirred in water to elute the residual compound. After that, a wet method was performed to measure the pH of the filtrate.
그러나, 이러한 습식 방식은 Li2O가 수분 접촉 시 대부분 LiOH로 변하기 때문에 Li2O 및 LiOH2의 구분이 어렵고 Li2SO4는 pH 측정 자체가 안되어, 상기 4가지 잔류 화합물 중 LiOH 및 Li2CO3 만이 측정되는 문제가 있다. 또한, 양극활물질의 표면에 다른 금속이 코팅된 경우 pH 적정 시 단일 피크가 아닌 다중 피크가 나타나 정확한 분석이 어렵다.However, in this wet method, it is difficult to distinguish between Li 2 O and LiOH 2 because most of Li 2 O changes to LiOH when in contact with water, and pH measurement itself is not available for Li 2 SO 4 , so LiOH and Li 2 CO among the four remaining compounds There is a problem that only 3 is measured. In addition, when other metals are coated on the surface of the cathode active material, multiple peaks rather than a single peak appear during pH titration, making accurate analysis difficult.
따라서, 본 발명의 목적은 리튬이차전지용 양극활물질에 존재하는 LiOH, Li2CO3, Li2SO4 및 Li2O의 4가지 잔류 리튬 화합물을 모두 분석할 수 있는 방법을 제공하는 것이다.Accordingly, an object of the present invention is to provide a method capable of analyzing all four residual lithium compounds of LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O present in a cathode active material for a lithium secondary battery.
본 발명의 일 측면에 따르면, 리튬이차전지용 양극활물질 내 잔류 리튬 화합물을 분석하는 방법으로서,According to one aspect of the present invention, as a method for analyzing residual lithium compounds in a cathode active material for a lithium secondary battery,
양극활물질 시료를 산소질소수소 분석기(ONH analyzer)로 분석하여 H 성분의 함량을 측정하는 단계; Analyzing the cathode active material sample with an oxygen nitrogen hydrogen analyzer (ONH analyzer) to measure the content of the H component;
상기 시료를 탄소-황 분석기(CS analyzer)로 분석하여 C 성분 및 S 성분의 함량을 측정하는 단계;Analyzing the sample with a carbon-sulfur analyzer (CS analyzer) to measure the content of C and S components;
상기 시료를 유도결합 플라즈마 발광 분석기(inductively coupled plasma optical emission spectrometer, ICP-OES)로 분석하여 Li 성분의 함량을 측정하는 단계; 및Measuring the content of Li components by analyzing the sample with an inductively coupled plasma optical emission spectrometer (ICP-OES); and
상기 H, C 및 S 성분의 측정 결과를 이용해 시료 내 LiOH, Li2CO3 및 Li2SO4의 함량을 각각 산출하고, 상기 Li 성분의 측정 결과를 이용해 시료 내 Li2O의 함량을 산출하는 단계를 포함하는 분석방법이 제공된다. Calculating the contents of LiOH, Li 2 CO 3 and Li 2 SO 4 in the sample using the measurement results of the H, C and S components, respectively, and calculating the content of Li 2 O in the sample using the measurement results of the Li component An analysis method comprising the steps is provided.
일 양태에서 본 발명의 양극활물질 시료는 건조 전처리를 거칠 수 있다.In one aspect, the cathode active material sample of the present invention may be subjected to a pre-drying treatment.
추가로 본 발명은 상기 방법으로 분석된 리튬 이차전지용 양극활물질로서, 전체 함량을 기준으로 잔류 LiOH의 함량이 0.1 내지 0.4 중량%, 잔류 Li2CO3의 함량이 0.1 내지 1.0 중량%, 잔류 Li2SO4의 함량이 0.1 내지 1.3 중량%, 및 잔류 Li2O의 함량이 0.2 내지 0.5인 양극활물질을 제공한다.In addition, the present invention is a cathode active material for a lithium secondary battery analyzed by the above method, the content of residual LiOH is 0.1 to 0.4% by weight, the content of residual Li 2 CO 3 is 0.1 to 1.0% by weight, and the residual Li 2 A cathode active material having SO 4 content of 0.1 to 1.3 wt% and residual Li 2 O content of 0.2 to 0.5 is provided.
본 발명에 따르면, 양극활물질 시료를 ONH 분석, CS 분석 및 ICP-OES 분석을 각각 수행하고, 이로부터 측정된 H, C, S 및 Li의 함량을 이용해 양극활물질에 존재하는 LiOH, Li2CO3, Li2SO4 및 Li2O의 4가지 잔류 리튬 화합물의 함량을 모두 분석할 수 있다. 특히, 상기 ONH 분석 및 CS 분석은 건식 방식으로 수행됨에 따라 기존 pH 적정을 통한 습식 방식과 달리 Li2O 및 LiOH2의 함량을 구분하여 측정할 수 있으며, 습식 방식에서 pH 적정이 안되었던 Li2SO4의 함량까지 측정함으로써, 리튬 이차전지의 정확한 성능 평가에 기여할 수 있다.According to the present invention, ONH analysis, CS analysis, and ICP-OES analysis are performed on a sample of the cathode active material, and LiOH, Li 2 CO 3 present in the cathode active material using the contents of H, C, S, and Li measured therefrom. , Li 2 SO 4 and Li 2 O content of all four residual lithium compounds can be analyzed. In particular, since the ONH analysis and the CS analysis are performed in a dry method, unlike the wet method through conventional pH titration, the contents of Li 2 O and LiOH 2 can be measured separately, and the Li 2 in which pH titration was not performed in the wet method By measuring the content of SO 4 , it can contribute to accurate performance evaluation of the lithium secondary battery.
본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 아니 되며, 발명자는 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야만 한다.The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as a meaning and concept consistent with the technical spirit of the present invention based on the principle that there is.
또한, 본 명세서에 기재된 실시예에 예시된 구성은 본 발명의 가장 바람직한 일 실시예에 불과할 뿐이고 본 발명의 기술적 사상을 모두 대변하는 것은 아니므로, 본 출원시점에 있어서 이들을 대체할 수 있는 다양한 균등물과 변형예들이 있을 수 있음을 이해하여야 한다.In addition, since the configurations exemplified in the embodiments described in this specification are only one of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, various equivalents that can replace them at the time of the present application It should be understood that there may be variations and variations.
본 발명의 일 실시형태는 리튬이차전지용 양극활물질 내 잔류 리튬 화합물인 LiOH, Li2CO3, Li2SO4 및 Li2O을 모두 분석할 수 있는 방법에 관한 것이다.One embodiment of the present invention relates to a method capable of analyzing all of LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O, which are residual lithium compounds in a cathode active material for a lithium secondary battery.
본 발명의 분석 대상인 양극활물질은 리튬 이차전지를 구성하는 양극에 사용될 수 있는 리튬 이온이 삽입되어 있는 화합물이며, 예컨대 LiCoO2, LiNiO2, LiMn2O4, LiCoPO4, LiFePO4, 및 LiNi1-x-y-zCoxM1yM2zO2(M1 및 M2는 서로 독립적으로 Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg 및 Mo로 이루어진 군으로부터 선택된 어느 하나이고, x, y 및 z는 서로 독립적으로 산화물 조성 원소들의 원자 분율로서 0≤x<0.5, 0≤y<0.5, 0≤z<0.5, 0<x+y+z≤1임)로 이루어진 군으로부터 선택된 하나 이상을 포함할 수 있다.The cathode active material to be analyzed in the present invention is a compound in which lithium ions are intercalated, which can be used in a cathode constituting a lithium secondary battery, such as LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCoPO 4 , LiFePO 4 , and LiNi 1- xyz Co x M1 y M2 z O 2 (M1 and M2 are each independently any one selected from the group consisting of Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo, x , y and z are, independently of each other, atomic fractions of oxide composition elements, 0≤x<0.5, 0≤y<0.5, 0≤z<0.5, 0<x+y+z≤1) selected from the group consisting of may contain more than
이러한 양극활물질은 Ni, Co, Mn 등의 전이금속을 함유하는 전구체 용액과 리튬 소스(Li2CO3, LiNO3, Li2O, Li2SO4 등)를 혼합한 후 900℃이상의 온도에서 열처리하여 입방정계의 스피넬 구조 또는 층상 구조를 갖는 결정으로 제조되는데, 상기 결정구조 내에 포함되지 못한 Li이 열처리 과정에서 공기 중에 존재하는 CO2와 반응하여 Li2CO3가 되거나 물과 반응하여 LiOH가 생성될 수 있다. 또한, 활물질 제조에 사용되어 미반응된 리튬 소스가 최종 활물질의 표면에 잔류할 수 있다. 일반적으로, LiOH, Li2CO3, Li2SO4 및 Li2O의 4가지 리튬 화합물을 양극활물질에 존재하지만 충방전에 관여하지 않는 부산물로 보고 있으며, 양극의 성능 확보를 위해서는 상기 4가지 잔류 리튬 화합물의 정확한 분석이 필요하다.Such a cathode active material is heat treated at a temperature of 900°C or higher after mixing a precursor solution containing transition metals such as Ni, Co, Mn, and a lithium source (Li 2 CO 3 , LiNO 3 , Li 2 O, Li 2 SO 4 , etc.) It is made into a crystal having a cubic spinel structure or a layered structure. Li, which is not included in the crystal structure, reacts with CO 2 present in the air during the heat treatment process to become Li 2 CO 3 or reacts with water to form LiOH It can be. In addition, an unreacted lithium source used in preparing the active material may remain on the surface of the final active material. In general, four types of lithium compounds, LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O, are considered as by-products that exist in cathode active materials but are not involved in charging and discharging. Accurate analysis of lithium compounds is required.
이를 위해, 본 발명에서는 양극활물질 시료를 준비하여 건식 방식으로 작동되는 산소질소수소 분석기(ONH analyzer) 및 탄소-황 분석기(CS analyzer), 그리고 습식 방식으로 작동되는 ICP-OES 분석기에 각각 도입하여 H, C, S 및 Li 성분들의 함량을 측정한 후, 상기 측정 값들을 통해 LiOH, Li2CO3, Li2SO4 및 Li2O의 함량을 산출한다.To this end, in the present invention, a sample of the cathode active material is prepared and introduced into an oxygen nitrogen hydrogen analyzer (ONH analyzer) and a carbon-sulfur analyzer (CS analyzer) operated in a dry method, and an ICP-OES analyzer operated in a wet method, respectively, to obtain H After measuring the contents of , C, S, and Li components, the contents of LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O are calculated through the measured values.
구체적으로, 상기 ONH 분석기는 시료를 가열로에서 용융시킨 후 배출된 산소, 질소 및 수소 가스 성분을 검출하는 장비로서, 당해 분야에 통상적으로 사용되는 ONH 분석기에 양극활물질 시료를 건조된 입자 형태로 도입하여 시료 내에 포함된 H 성분의 함량을 측정할 수 있다. 본 발명은, Li2O가 수분 접촉 시 대부분 LiOH로 변하기 때문에 Li2O 및 LiOH2의 구분이 어렵다는 문제점을 해결하기 위해, 양극활물질 내 수분을 건조하는 단계를 포함한다. 구체적으로 예를 들면 본 발명의 양극활물질 시료는 100 내지 200℃, 예를 들면 110 내지 180℃, 또는 120 내지 160℃에서 10-2 내지 10-10torr, 예를 들면 10-4 내지 10-8torr, 또는 10-5 내지 10-7torr로 2 내지 15시간, 예를 들면 3 내지 10시간, 또는 5 내지 8시간 동안 건조된 것을 사용할 수 있다.Specifically, the ONH analyzer is a device for detecting oxygen, nitrogen, and hydrogen gas components discharged after melting the sample in a heating furnace, and introduces the cathode active material sample in the form of dried particles to the ONH analyzer commonly used in the field. Thus, the content of the H component included in the sample can be measured. The present invention, in order to solve the problem that it is difficult to distinguish between Li 2 O and LiOH 2 because Li 2 O is mostly changed to LiOH upon contact with water, includes drying the moisture in the cathode active material. Specifically, for example, the cathode active material sample of the present invention is 100 to 200 ℃, for example, 110 to 180 ℃, or 120 to 160 ℃ 10 -2 to 10 -10 torr, for example, 10 -4 to 10 -8 torr, or 10 -5 to 10 -7 torr for 2 to 15 hours, for example, 3 to 10 hours, or 5 to 8 hours may be used.
상기 CS 분석기는 시료를 산소 기류 속에서 연소시켜 생성된 탄소 및 황의 함량을 검출하는 장비로서, 당해 분야에 통상적으로 사용되는 CS 분석기의 세라믹 가열로에 조연제와 함께 양극활물질 시료를 건조된 입자 형태로 도입하고, 고주파 유도장치에서 산소 가스를 공급하여, 시료 내에 포함된 C 성분 및 S 성분의 함량을 측정할 수 있다.The CS analyzer is a device for detecting the content of carbon and sulfur produced by burning a sample in an oxygen stream, and the cathode active material sample is dried in the form of particles along with a flame retardant in a ceramic heating furnace of a CS analyzer commonly used in the field. and by supplying oxygen gas from a high-frequency induction device, the contents of the C component and S component included in the sample can be measured.
이러한 ONH 분석기와 CS 분석기를 이용하는 경우 양극활물질 시료가 수분과 접촉하지 않으므로 Li2O 및 LiOH2의 함량을 구분하여 측정할 수 있다. 즉, 기존 방법에서 습식 방식의 pH 적정을 이용해 양극활물질 내 잔류 리튬 함량을 측정할 때 Li2O가 수분 접촉으로 LiOH로 변하는 현상으로, LiOH 및 Li2CO3의 측정에 국한되었던 분석 방법의 한계를 극복할 수 있다. 또한, 습식 방식에서 pH 적정이 안되었던 Li2SO4를 CS 분석기로 측정된 S 성분의 함량을 이용해 분석할 수 있다.When the ONH analyzer and the CS analyzer are used, the contents of Li 2 O and LiOH 2 can be separately measured because the cathode active material sample does not come into contact with moisture. In other words, when measuring the residual lithium content in the cathode active material using wet pH titration in the existing method, Li 2 O changes to LiOH due to contact with water. can overcome In addition, Li 2 SO 4 , which was not pH titrated in the wet method, can be analyzed using the content of S component measured by a CS analyzer.
본 발명의 일 실시형태에서, 상기 CS 분석으로 측정된 C 성분 및 S 성분의 결과를 이용해 Li2CO3 및 Li2SO4의 함량을 각각 산출하며, 상기 Li2CO3의 함량은 양극활물질의 전체 중량을 기준으로 0.1 내지 1.0 중량%, 그리고 Li2SO4의 함량은 양극활물질의 전체 중량을 기준으로 0.1 내지 1.3 중량%일 수 있다. 구체적으로, CS 분석기를 이용한 Li 함량 계산식은 수학식 1 내지 4와 같이 할 수 있다.In one embodiment of the present invention, the contents of Li 2 CO 3 and Li 2 SO 4 are calculated using the results of the C component and the S component measured by the CS analysis, respectively, and the Li 2 CO 3 content of the positive electrode active material 0.1 to 1.0 wt% based on the total weight, and the content of Li 2 SO 4 may be 0.1 to 1.3 wt% based on the total weight of the cathode active material. Specifically, the Li content calculation formula using the CS analyzer can be as shown in Equations 1 to 4.
[수학식 1][Equation 1]
상기 식에서,In the above formula,
Li는 리튬의 함량이고,Li is the content of lithium,
C는 탄소의 함량이고,C is the content of carbon,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMc는 탄소의 원자질량이다.AM c is the atomic mass of carbon.
[수학식 2][Equation 2]
상기 식에서,In the above formula,
Li2CO3는 리튬의 함량이고,Li 2 CO 3 is the content of lithium;
C는 탄소의 함량이고,C is the content of carbon,
MWLi2CO3는 Li2CO3의 중량평균분자량이고,MW Li2CO3 is the weight average molecular weight of Li 2 CO 3 ;
AMc는 탄소의 원자질량이다.AM c is the atomic mass of carbon.
[수학식 3][Equation 3]
상기 식에서,In the above formula,
Li는 리튬의 함량이고,Li is the content of lithium,
S는 황의 함량이고,S is the sulfur content,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMS는 황의 원자질량이다.AM S is the atomic mass of sulfur.
[수학식 4][Equation 4]
상기 식에서,In the above formula,
Li2SO4는 Li2SO4의 함량이고,Li 2 SO 4 is the content of Li 2 SO 4 ;
S는 황의 함량이고,S is the sulfur content,
MWLi2SO4는 Li2SO4의 중량평균분자량이고,MW Li2SO4 is the weight average molecular weight of Li 2 SO 4 ;
AMS는 황의 원자질량이다.AM S is the atomic mass of sulfur.
한편, 상기 ICP-OES 분석은 양극활물질 시료를 분취하여 초순수에 용해시킨 용액으로 사용하여 수행될 수 있다. 구체적으로 예를 들면, ICP-OES 분석 시 양극활물질 시료와 초순수를 1:50 내지 1:500중량부, 예를 들면 1:50 내지 300중량부, 또는 1:50 내지 200중량부, 또는 1:80 내지 150중량부로, 1 내지 60분, 예를 들면 1 내지 40분, 또는 5 내지 30분, 또는 5 내지 15분 동안 함침하는 단계를 포함할 수 있다. ICP-OES로부터 분석되는 값은 양극활물질 내 총 리튬의 함량(Li wt%), 즉 LiOH, Li2CO3, Li2SO4, Li2O등 모든 Li 화합물의 함량을 의미한다. On the other hand, the ICP-OES analysis may be performed by using a solution obtained by taking a sample of the cathode active material and dissolving it in ultrapure water. Specifically, for example, during ICP-OES analysis, 1:50 to 1:500 parts by weight of the cathode active material sample and ultrapure water, for example, 1:50 to 300 parts by weight, or 1:50 to 200 parts by weight, or 1: 80 to 150 parts by weight for 1 to 60 minutes, for example 1 to 40 minutes, or 5 to 30 minutes, or 5 to 15 minutes. The value analyzed by ICP-OES means the total lithium content (Li wt%) in the cathode active material, that is, the content of all Li compounds such as LiOH, Li 2 CO 3 , Li 2 SO 4 , and Li 2 O.
또한, 상기 ONH 분석으로 측정된 H 성분의 결과를 이용해 LiOH의 함량을 산출하며, 산출된 LiOH의 함량은 양극활물질의 전체 중량을 기준으로 0.1 내지 0.4 중량%일 수 있다. 구체적으로, ONH 분석기를 이용한 Li 함량 계산식은 수학식 5 및 6과 같이 할 수 있다.In addition, the content of LiOH is calculated using the result of the H component measured by the ONH analysis, and the calculated content of LiOH may be 0.1 to 0.4% by weight based on the total weight of the cathode active material. Specifically, the Li content calculation formula using the ONH analyzer may be as Equations 5 and 6.
[수학식 5][Equation 5]
상기 식에서,In the above formula,
Li는 리튬의 함량이고,Li is the content of lithium,
H는 수소의 함량이고,H is the content of hydrogen,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMH는 수소의 원자질량이다.AM H is the atomic mass of hydrogen.
[수학식 6][Equation 6]
상기 식에서,In the above formula,
LiOH는 LiOH의 함량이고,LiOH is the content of LiOH,
H는 수소의 함량이고,H is the content of hydrogen,
MWLiOH는 LiOH의 중량평균분자량이고,MW LiOH is the weight average molecular weight of LiOH,
AMH는 수소의 원자질량이다.AM H is the atomic mass of hydrogen.
상기 ICP-OES 분석은 불활성 기체인 아르곤 가스로 유도된 고온의 플라즈마로 시료에 높은 열에너지를 가함으로써 시료 내 원자, 이온들을 들뜬 상태(excited state)로 만든 후 다시 낮은 에너지 준위로 돌아오면서 방출하는 선을 검출하여 성분 분석을 수행하는 것으로, 양극활물질 시료 내에 함유된 전체 잔류 Li의 성분을 측정할 수 있다.The ICP-OES analysis is a high-temperature plasma induced by an inert gas, argon gas, which applies high thermal energy to the sample to make atoms and ions in the sample excited state, and then returns to a low energy level and emits radiation. By detecting and performing component analysis, it is possible to measure the components of the total residual Li contained in the positive electrode active material sample.
본 발명의 일 실시형태에서, 상기 양극활물질 시료의 초순수 처리는 분취 시료 100mg을 기준으로 초순수를 0.1 내지 100 ㎖의 범위로 첨가한 후 상온에서 약 5분 동안 교반하는 방식으로 수행될 수 있다. 상기 초순수 처리된 용액을 여과하여 용해되지 않은 성분을 제거한 후, 남은 여과액을 당해 분야에 통상적으로 사용되는 ICP-OES 분석기에 도입하여 성분 분석을 수행할 수 있다.In one embodiment of the present invention, ultrapure water treatment of the cathode active material sample may be performed by adding ultrapure water in a range of 0.1 to 100 ml based on 100 mg of the preparative sample and then stirring at room temperature for about 5 minutes. After filtering the solution treated with ultrapure water to remove undissolved components, component analysis may be performed by introducing the remaining filtrate into an ICP-OES analyzer commonly used in the art.
상기 ICP-OES 분석으로 측정된 양극활물질 시료 내 전체 잔류 Li 성분에서 LiOH, Li2CO3 및 Li2SO4에 해당되는 Li 함량을 차감하여 Li2O의 함량을 산출하며, 상기 산출된 Li2O의 함량은 양극활물질의 전체 중량을 기준으로 0.2 내지 0.5 중량%일 수 있다. 구체적으로, Li2O 함량의 계산식은 수학식 7과 같이 할 수 있다.The content of Li 2 O is calculated by subtracting the Li content corresponding to LiOH, Li 2 CO 3 and Li 2 SO 4 from the total residual Li component in the positive electrode active material sample measured by the ICP-OES analysis, and the calculated Li 2 The content of O may be 0.2 to 0.5% by weight based on the total weight of the cathode active material. Specifically, the calculation formula for the Li 2 O content can be as shown in Equation 7.
[수학식 7][Equation 7]
상기 식에서,In the above formula,
용출 리튬(wt%)은 양극활물질을 ICP-OES로 분석한 총 리튬 ?량이고,Elution lithium (wt%) is the total amount of lithium analyzed by ICP-OES for the cathode active material,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMH는 수소의 원자질량이고,AM H is the atomic mass of hydrogen,
AMC는 탄소의 원자질량이고,AM C is the atomic mass of carbon,
AMS는 황의 원자질량이고,AM S is the atomic mass of sulfur,
MWLi2O는 Li2O의 중량평균 분자량이다. MW Li2O is the weight average molecular weight of Li 2 O.
본 발명에서 ICP-OES 분석, CS 분석 및 ONH 분석 단계의 순서는 특별히 한정되지 않는다.In the present invention, the order of the steps of ICP-OES analysis, CS analysis and ONH analysis is not particularly limited.
상기와 같은 분석과정에 따르면, 리튬 이차전지의 양극활물질에 존재하면서 충방전에는 관여하지 않는 LiOH, Li2CO3, Li2SO4 및 Li2O의 4가지 잔류 리튬 화합물의 함량을 모두 분석할 수 있으며, 분석된 이들 잔류 리튬 화합물의 함량을 적용하여 양극 및 리튬 이차전지의 정확한 성능 평가가 가능하다.According to the analysis process as described above, the contents of all four residual lithium compounds, LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O, which are present in the cathode active material of the lithium secondary battery and are not involved in charging and discharging, can be analyzed. It is possible to accurately evaluate the performance of the positive electrode and lithium secondary battery by applying the analyzed content of these residual lithium compounds.
따라서, 본 발명은 상기 방법으로 분석된 리튬 이차전지용 양극활물질을 추가로 제공한다.Accordingly, the present invention further provides a cathode active material for a lithium secondary battery analyzed by the above method.
상기 양극활물질은 전체 함량을 기준으로 잔류 LiOH의 함량이 0.1 내지 0.4 중량%, 잔류 Li2CO3의 함량이 0.1 내지 1.0 중량%, 잔류 Li2SO4의 함량이 0.1 내지 1.3 중량%, 및 잔류 Li2O의 함량이 0.2 내지 0.5 중량%일 수 있다.The cathode active material has a residual LiOH content of 0.1 to 0.4 wt %, a residual Li 2 CO 3 content of 0.1 to 1.0 wt %, a residual Li 2 SO 4 content of 0.1 to 1.3 wt %, and a residual Li 2 CO 4 content of 0.1 to 1.3 wt %, based on the total content. The content of Li 2 O may be 0.2 to 0.5% by weight.
이하, 본 발명의 이해를 돕기 위하여 실시예를 들어 상세하게 설명하기로 한다. 그러나, 본 발명에 따른 실시예들은 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 하기 실시예에 한정되는 것으로 해석되어서는 안 된다. 본 발명의 실시예들은 당업계에서 평균적인 지식을 가진 자에게 본 발명을 보다 완전하게 설명하기 위해 제공되는 것이다. Hereinafter, examples will be described in detail to aid understanding of the present invention. However, the embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the following examples. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.
실시예: Example:
(단계 1) ICP-OES를 이용한 Li 함량 분석(용출 리튬)(Step 1) Li content analysis using ICP-OES (eluted lithium)
0.1g의 Li[Ni0.86Co0.05Mn0.07Al0.02]O2의 양극활물질을 10g의 중류수에 넣고 10분간 방치한 후, 필터하여 여액을 ICP-OES(AVIO 500, Perkin Elmer)로 분석하였다.0.1 g of the cathode active material of Li[Ni 0.86 Co 0.05 Mn 0.07 Al 0.02 ]O 2 was placed in 10 g of distilled water, left for 10 minutes, filtered, and the filtrate was analyzed by ICP-OES (AVIO 500, Perkin Elmer).
<ICP-OES 분석조건><ICP-OES analysis conditions>
순방향 전력(Forward Power): 1300WForward Power: 1300W
토치 높이(Torch Height): 15㎜Torch Height: 15mm
플라즈마 가스 유량: 15.00L/minPlasma gas flow: 15.00L/min
시료 가스 유량: 0.8L/minSample gas flow: 0.8L/min
보조가스 유량: 0.20L/minAssist gas flow: 0.20L/min
펌프 속도: 1.5㎖/minPump speed: 1.5 mL/min
(단계 2) 탄소-황 분석기(CS analyzer)를 이용하여 Li 함량 계산(Step 2) Calculate Li content using a carbon-sulfur analyzer (CS analyzer)
150℃에서 10-6 torr로 6시간 동안 진공 건조된 0.2g의 양극재 활물질을 알루미나 도가니(alumina crucible)에 넣어 무게를 정확히 측정하였다. 시료를 넣은 알루미나 도가니에 조연제(Fe, Leco사)를 시료의 양에 맞게 1.8~2.0g을 첨가한 다음, 하부의 전극(electrode)에 올려 놓았다. 상부로 시료를 주입하여 연소시켜 C, S 성분을 분석하고, 완료된 후 알루미나 도가니를 제거하였다. 시료를 2회 이상 반복 분석하여 정량 분석을 진행하였다.0.2 g of the cathode material active material vacuum-dried at 150° C. at 10 −6 torr for 6 hours was put into an alumina crucible and the weight was accurately measured. 1.8-2.0 g of a softener (Fe, Leco) was added according to the amount of the sample in an alumina crucible containing the sample, and then placed on the lower electrode. A sample was injected into the top and burned to analyze C and S components, and after completion, the alumina crucible was removed. Quantitative analysis was performed by repeating the sample twice or more.
[수학식 1][Equation 1]
상기 식에서,In the above formula,
Li는 리튬의 함량이고,Li is the content of lithium,
C는 탄소의 함량이고,C is the content of carbon,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMc는 탄소의 원자질량이다.AM c is the atomic mass of carbon.
[수학식 2][Equation 2]
상기 식에서,In the above formula,
Li2CO3는 리튬의 함량이고,Li 2 CO 3 is the content of lithium;
C는 탄소의 함량이고,C is the content of carbon,
MWLi2CO3는 Li2CO3의 중량평균분자량이고,MW Li2CO3 is the weight average molecular weight of Li 2 CO 3 ;
AMc는 탄소의 원자질량이다.AM c is the atomic mass of carbon.
[수학식 3][Equation 3]
상기 식에서,In the above formula,
Li는 리튬의 함량이고,Li is the content of lithium,
S는 황의 함량이고,S is the sulfur content,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMS는 황의 원자질량이다.AM S is the atomic mass of sulfur.
[수학식 4][Equation 4]
상기 식에서,In the above formula,
Li2SO4는 Li2SO4의 함량이고,Li 2 SO 4 is the content of Li 2 SO 4 ;
S는 황의 함량이고,S is the sulfur content,
MWLi2SO4는 Li2SO4의 중량평균분자량이고,MW Li2SO4 is the weight average molecular weight of Li 2 SO 4 ;
AMS는 황의 원자질량이다.AM S is the atomic mass of sulfur.
(단계 3) ONH 분석기를 이용하여 Li 함량 분석(Step 3) Analysis of Li content using ONH analyzer
그래파이트(graphite) 도가니를 이용하여 블랭크(blank)를 3회 측정하였다. O, N, H 표준품 시료를 이용하여 교정(calibration)을 진행하였다. 150℃에서 10-6 torr로 6시간 동안 진공 건조된 0.02g의 양극활물질 Li[Ni0.86Co0.05Mn0.07Al0.02]O2을 주석(tin) 캡슐에 넣고 실링하였다. 그 다음 주석 캡슐을 니켈 바스켓(Ni basket)에 담았다. 니켈 바스켓을 시료 투입구에 넣고 H 분석을 진행하였다. 시료를 2회 이상 반복하여 정량분석하였다.A blank was measured three times using a graphite crucible. Calibration was performed using O, N, H standard samples. 0.02 g of a cathode active material Li[Ni 0.86 Co 0.05 Mn 0.07 Al 0.02 ]O 2 vacuum-dried at 150° C. at 10 −6 torr for 6 hours was placed in a tin capsule and sealed. The tin capsules were then placed in a nickel basket. A nickel basket was put into the sample inlet and H analysis was performed. Samples were repeatedly analyzed twice or more for quantitative analysis.
[수학식 5][Equation 5]
상기 식에서,In the above formula,
Li는 리튬의 함량이고,Li is the content of lithium,
H는 수소의 함량이고,H is the content of hydrogen,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMH는 수소의 원자질량이다.AM H is the atomic mass of hydrogen.
[수학식 6][Equation 6]
상기 식에서,In the above formula,
LiOH는 LiOH의 함량이고,LiOH is the content of LiOH,
H는 수소의 함량이고,H is the content of hydrogen,
MWLiOH는 LiOH의 중량평균분자량이고,MW LiOH is the weight average molecular weight of LiOH,
AMH는 수소의 원자질량이다.AM H is the atomic mass of hydrogen.
(단계 4) 단계 1 내지 3으로부터 Li2O 함량 계산(Step 4) Calculate the Li 2 O content from Steps 1 to 3
[수학식 7][Equation 7]
용출 리튬(wt%)은 양극활물질을 ICP-OES로 분석한 총 리튬 함량이고,Elution lithium (wt%) is the total lithium content of the cathode active material analyzed by ICP-OES,
AMLi는 리튬의 원자질량이고,AM Li is the atomic mass of lithium,
AMH는 수소의 원자질량이고,AM H is the atomic mass of hydrogen,
AMC는 탄소의 원자질량이고,AM C is the atomic mass of carbon,
AMS는 황의 원자질량이고,AM S is the atomic mass of sulfur,
MWLi2O는 Li2O의 중량평균 분자량이다.MW Li2O is the weight average molecular weight of Li 2 O.
비교예: Comparative example:
Li[Ni0.86Co0.05Mn0.07Al0.02]O2의 양극활물질 시료 4종을 준비한 후, 각 시료의 5g을 분취하여 초순수 1000ml에 첨가하여 용해시켰다.After preparing 4 types of cathode active material samples of Li[Ni 0.86 Co 0.05 Mn 0.07 Al 0.02 ]O 2 , 5 g of each sample was aliquoted and added to 1000 ml of ultrapure water to dissolve them.
각각의 시료 용액을 0.45㎛ PTFE 필터로 여과하여 용해되지 않은 성분을 제거한 후, 남은 여과액(상층액)에 대해 pH 적정을 수행하여 시료 내 LiOH 및 Li2CO3의 함량을 측정하였다.After each sample solution was filtered through a 0.45 μm PTFE filter to remove undissolved components, pH titration was performed on the remaining filtrate (supernatant) to measure the contents of LiOH and Li 2 CO 3 in the sample.
상기 실시예 및 비교예에서 산출된 성분들의 함량 결과를 중량%(wt%)로 표시하여 하기 표 1에 나타내었다.The content results of the components calculated in the Examples and Comparative Examples are shown in Table 1 below in terms of weight% (wt%).
상기 표 1로부터, 실시예에 따라 양극활물질 시료에 대해 건식 및 습식 방식의 성분 분석을 각각 수행한 후 그 결과를 종합한 경우 LiOH, Li2CO3, Li2SO4 및 Li2O의 4가지 잔류 리튬 화합물의 함량을 모두 측정할 수 있으며, 시료의 전체 함량을 기준으로 잔류 LiOH의 함량이 0.1 내지 0.4 중량%, 잔류 Li2CO3의 함량이 0.1 내지 1.0 중량%, 잔류 Li2SO4의 함량이 0.1 내지 1.3 중량%, 및 잔류 Li2O의 함량이 0.2 내지 0.5 중량%임을 확인할 수 있다.From Table 1, when dry and wet component analysis was performed on the positive electrode active material sample according to the embodiment, respectively, and the results were combined, four types of LiOH, Li 2 CO 3 , Li 2 SO 4 and Li 2 O The content of all residual lithium compounds can be measured, and the content of residual LiOH is 0.1 to 0.4% by weight, the content of residual Li 2 CO 3 is 0.1 to 1.0% by weight, and the content of residual Li 2 SO 4 is 0.1 to 1.0% by weight, based on the total content of the sample. It can be seen that the content is 0.1 to 1.3% by weight, and the content of residual Li 2 O is 0.2 to 0.5% by weight.
한편, 비교예에서는 습식 방식의 pH 적정 분석만을 수행함에 따라 LiOH 및 Li2CO3 만이 측정되었다. 상기 비교예에 따라 측정된 LiOH는 Li2O가 LiOH로 변한 함량을 포함하는 것으로서, 실시예에 따른 LiOH 및 Li2O의 합과 유사함을 확인할 수 있다. 이에, 실시예에 따라 측정된 LiOH, Li2O 및 Li2CO3의 총합과 비교예에 따라 측정된 LiOH 및 Li2CO3의 총합을 잔류 리튬 함량으로서 비교하였으며, 그 결과를 하기 표 2에 나타내었다.On the other hand, in Comparative Example, only LiOH and Li 2 CO 3 were measured as only wet pH titration analysis was performed. It can be seen that the LiOH measured according to the comparative example includes the amount of Li 2 O converted to LiOH, and is similar to the sum of LiOH and Li 2 O according to the example. Therefore, the total amount of LiOH, Li 2 O, and Li 2 CO 3 measured according to Examples and the total amount of LiOH and Li 2 CO 3 measured according to Comparative Example were compared as residual lithium content, and the results are shown in Table 2 below. showed up
상기 표 2로부터, 실시예의 잔류 리튬 함량은 비교예와 비교할 때 상대표준편차(RSD)가 5% 이내임을 확인할 수 있다.From Table 2, it can be seen that the relative standard deviation (RSD) of the residual lithium content of Examples is within 5% when compared to Comparative Examples.
Claims (11)
양극활물질 시료를 산소질소수소 분석기(ONH analyzer)로 분석하여 H 성분의 함량을 측정하는 단계;
상기 시료를 탄소-황 분석기(CS analyzer)로 분석하여 C 성분 및 S 성분의 함량을 측정하는 단계;
상기 시료를 유도결합 플라즈마 발광 분석기(inductively coupled plasma optical emission spectrometer, ICP-OES)로 분석하여 Li 성분의 함량을 측정하는 단계; 및
상기 H, C 및 S 성분의 측정 결과를 이용해 시료 내 LiOH, Li2CO3 및 Li2SO4의 함량을 각각 산출하고, 상기 Li 성분의 측정 결과를 이용해 시료 내 Li2O의 함량을 산출하는 단계를 포함하고,
수학식 7에 따라 Li2O의 함량을 계산하는 단계를 포함하는 분석방법:
[수학식 7]
상기 식에서,
용출 리튬(wt%)은 양극활물질을 ICP-OES로 분석한 총 리튬 함량이고,
AMLi는 리튬의 원자질량이고,
AMH는 수소의 원자질량이고,
AMC는 탄소의 원자질량이고,
AMS는 황의 원자질량이고,
MWLi2O는 Li2O의 중량평균 분자량이다.As a method of analyzing residual lithium compounds in cathode active materials for lithium secondary batteries,
Analyzing the cathode active material sample with an oxygen nitrogen hydrogen analyzer (ONH analyzer) to measure the content of the H component;
Analyzing the sample with a carbon-sulfur analyzer (CS analyzer) to measure the content of C and S components;
Measuring the content of Li components by analyzing the sample with an inductively coupled plasma optical emission spectrometer (ICP-OES); and
Calculating the contents of LiOH, Li 2 CO 3 and Li 2 SO 4 in the sample using the measurement results of the H, C and S components, respectively, and calculating the content of Li 2 O in the sample using the measurement results of the Li component contains steps,
Analytical method comprising calculating the content of Li 2 O according to Equation 7:
[Equation 7]
In the above formula,
Elution lithium (wt%) is the total lithium content of the cathode active material analyzed by ICP-OES,
AM Li is the atomic mass of lithium,
AM H is the atomic mass of hydrogen,
AM C is the atomic mass of carbon,
AM S is the atomic mass of sulfur,
MW Li2O is the weight average molecular weight of Li 2 O.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20210157632 | 2021-11-16 | ||
| KR1020210157632 | 2021-11-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR20230071743A true KR20230071743A (en) | 2023-05-23 |
Family
ID=86544207
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020220151580A KR20230071744A (en) | 2021-11-16 | 2022-11-14 | Analysis method of residual lithium compound present in cathode active material |
| KR1020220151533A KR20230071743A (en) | 2021-11-16 | 2022-11-14 | Analysis method of residual lithium compound present in cathode active material |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020220151580A KR20230071744A (en) | 2021-11-16 | 2022-11-14 | Analysis method of residual lithium compound present in cathode active material |
Country Status (1)
| Country | Link |
|---|---|
| KR (2) | KR20230071744A (en) |
-
2022
- 2022-11-14 KR KR1020220151580A patent/KR20230071744A/en unknown
- 2022-11-14 KR KR1020220151533A patent/KR20230071743A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| KR20230071744A (en) | 2023-05-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | An in situ formed surface coating layer enabling LiCoO2 with stable 4.6 V high‐voltage cycle performances | |
| CN111512397B (en) | Solid electrolyte | |
| DK2761687T3 (en) | condensed polyanionelektrode | |
| Tesfamhret et al. | On the manganese dissolution process from LiMn2O4 cathode materials | |
| CN109980211A (en) | Sodium-ion battery positive material and preparation method and application | |
| Klee et al. | High‐Performance Na3V2 (PO4) 3/C Cathode for Sodium‐Ion Batteries Prepared by a Ball‐Milling‐Assisted Method | |
| Wang et al. | Thermal stability between sulfide solid electrolytes and oxide cathode | |
| US20180083275A1 (en) | Composite Powder for Use in an Anode of a Lithium Ion Battery, Method for Manufacturing a Composite Powder and Lithium Ion Battery | |
| JP2013008671A (en) | High voltage rechargeable magnesium cell | |
| Gryzlov et al. | Behavior of LiFePO4/CPVDF/Ag-based cathode materials obtained using polyvinylidene fluoride as the carbon source | |
| Wu et al. | Effect of Cu substitution on structures and electrochemical properties of Li [NiCo 1− x Cu x Mn] 1/3 O 2 as cathode materials for lithium ion batteries | |
| Madec et al. | Exploring interactions between electrodes in Li [NixMnyCo1-xy] O2/graphite cells through electrode/electrolyte interfaces analysis | |
| Jena et al. | Monitoring the phase evolution in LiCoO2 electrodes during battery cycles using in‐situ neutron diffraction technique | |
| Zhong et al. | Synthesis of LiVPO4F with high electrochemical performance by sol-gel route | |
| CN110943206A (en) | Positive active material, method for preparing same, and battery comprising same | |
| Ibing et al. | The role of the pH value in water-based pastes on the processing and performance of Ni-rich LiNi0. 5Mn0. 3Co0. 2O2 based positive electrodes | |
| CN111211302B (en) | Lithium ion battery anode material and preparation method thereof, lithium ion battery anode, lithium ion battery and power utilization equipment | |
| KR20230071743A (en) | Analysis method of residual lithium compound present in cathode active material | |
| JP2014194868A (en) | Cathode active material for lithium ion battery, cathode for lithium ion battery, and lithium ion battery | |
| Su et al. | High-capacity and superior behavior of the Ni–Cu co-doped spinel LiMn 2 O 4 cathodes rapidly prepared via microwave-induced solution flameless combustion | |
| JP2024512911A (en) | Analysis method for residual lithium compounds in positive electrode active material | |
| CN108199013A (en) | Carbon coating ternary material and preparation method thereof | |
| CN116964448A (en) | Method for analyzing residual lithium compound in anode active material | |
| CN108711612B (en) | Reduced graphene oxide-metal carbide composite material, and preparation method and application thereof | |
| CN112945791A (en) | Evaluation method for dispersibility of lithium ion secondary battery slurry |