WO2023143516A1 - 一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用 - Google Patents

一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用 Download PDF

Info

Publication number
WO2023143516A1
WO2023143516A1 PCT/CN2023/073560 CN2023073560W WO2023143516A1 WO 2023143516 A1 WO2023143516 A1 WO 2023143516A1 CN 2023073560 W CN2023073560 W CN 2023073560W WO 2023143516 A1 WO2023143516 A1 WO 2023143516A1
Authority
WO
WIPO (PCT)
Prior art keywords
component
positive electrode
lithium battery
battery
lithium
Prior art date
Application number
PCT/CN2023/073560
Other languages
English (en)
French (fr)
Inventor
邱纪亮
杨琪
王加加
郭鲁新
俞会根
Original Assignee
北京卫蓝新能源科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 北京卫蓝新能源科技有限公司 filed Critical 北京卫蓝新能源科技有限公司
Publication of WO2023143516A1 publication Critical patent/WO2023143516A1/zh

Links

Classifications

    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • H01M4/04—Processes of manufacture in general
    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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

Definitions

  • the invention relates to the technical field of lithium batteries, in particular to a high-rate, long-cycle, high-safety lithium battery positive electrode sheet and a preparation method and application thereof.
  • Lithium-ion batteries have the advantages of high energy density, good cycle performance, long service life, low self-discharge, and no memory effect. They gradually occupy a larger application market in energy storage, power batteries, and 3C electronics, and have broad application prospects. .
  • Lithium batteries continue to develop in the direction of increasing energy density to provide better battery life for electric vehicles, digital products and other power electronic products.
  • Increasing the loading capacity and compaction density of the electrode pole piece, especially the loading capacity and compaction density of the positive pole piece, is an effective way to increase the energy density of the battery.
  • the thickness of the positive electrode active material layer increases and the porosity decreases, which leads to difficulties in the transmission of lithium ions in the positive electrode sheet, serious polarization of the battery, and the discharge specific capacity and capacity of the battery.
  • the rate performance is reduced, and the cycle stability is also reduced.
  • battery safety is often more difficult to guarantee. So far, there is no technology that can solve the above problems at the same time.
  • the existing methods to improve the battery rate performance are:
  • the invention patent application document with publication number CN113224287A discloses a strontium-doped ternary lithium-ion battery positive electrode material (Li 1-x Sr x [Ni 1-yz Co y M z ]O 2 wherein, M is one of metals Mn and Al, 0 ⁇ x ⁇ 0.1, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 1) and its preparation method and application.
  • strontium metal ions to replace lithium sites, the degree of cation mixing can be reduced, lithium ion channels can be expanded, and the layered structure can be stabilized, effectively improving the rate performance of lithium batteries. While this method improves the rate performance, it often brings the problem of accelerated capacity fading to the material.
  • the existing methods to improve battery safety performance are:
  • Positive electrode coating the invention patent application document with the publication number CN113809280A discloses a positive electrode material and its preparation and application. By changing the interaction between the sintering technology and the application of the coating agent, a material with a similar surface A positive electrode material with a similar coating effect.
  • the coating layer on the surface of the positive electrode material prepared by the method has a large coverage, which significantly reduces the erosion degree of the electrolyte to the material particles, effectively reduces the probability of side reactions, and thus improves the safety of the material.
  • the method is complex and affects the battery rate performance.
  • the invention patent application document with the publication number CN113690490A discloses a phosphite-based lithium-ion battery electrolyte additive, which can effectively prevent the combustion or explosion of organic solvents, improve the thermal stability of the electrolyte itself, and improve the positive electrode. Stability, improving the stability and safety of battery cycling. Disadvantages: damage battery electrical performance such as cycle performance and rate performance.
  • Diaphragm coating the invention patent application document with publication number CN108963153B discloses a lithium-ion battery diaphragm and its preparation method, which is coated with a water-based ceramic slurry coating on at least one side of the base film layer, and then coated on the water-based ceramic The surface of the slurry coating and/or the base film layer is coated with a composite adhesive layer of polyethylene glycol and polymethyl methacrylate.
  • the prepared lithium-ion battery diaphragm has good bonding performance, can prevent dislocation of pole pieces from short circuit, improve battery hardness, and thus greatly improve the safety performance of the battery. Cons: damages the battery rate performance.
  • CN 108365260 B discloses a quasi-solid electrolyte, the raw material composition includes polymer, ceramic electrolyte, lithium salt and ionic liquid.
  • the ceramic electrolyte includes a main phase lithium titanium aluminum phosphate and a heterogeneous phase TiP 2 O 7 /TiO 2 .
  • the impurity phase content is 2-7%, and the mass ratio of TiP 2 O 7 to TiO 2 is 1.5-2.5:1.
  • the comprehensive performance of the quasi-solid electrolyte prepared by the ceramic electrolyte with this heterogeneous content is the best.
  • the impurity phase with special composition and content has lithium storage properties, can improve the transmission performance of lithium ions, and can reduce the contact between the main phase lithium titanium aluminum phosphate and metal lithium, and improve the interface stability with metal lithium.
  • this patent does not improve the electrical performance and safety performance of the positive electrode, and the method is not compatible with the mainstream preparation process of the existing lithium-ion battery positive electrode sheet, and cannot be adapted for large-scale applications.
  • CN113707880A relates to a positive pole piece containing solid electrolyte and its preparation method and application, aiming at improving the rate performance of the battery, improving cycle performance and safety performance. Since the solid electrolyte contained in the positive electrode slurry is conducive to the translocation and infiltration of the electrolyte in the horizontal and vertical directions of the electrode sheet, it is beneficial to the storage and infiltration of the electrolyte, and it is also conducive to alleviating the expansion of the electrode sheet during the cycle of the cell and reducing the expansion process of the electrode sheet. The amount of electrolyte that is squeezed out under pressure makes the battery cell still contain sufficient electrolyte in the pole piece after a long-term cycle to ensure the normal transmission of lithium ions, thereby improving cycle performance.
  • the present invention provides a high-rate, long-cycle, high-safety lithium battery positive electrode sheet and its preparation method and application.
  • the positive electrode sheet of the present invention includes a current collector and a positive electrode material layer located on the surface of the current collector, and the positive electrode material layer includes a positive electrode active material, a conductive agent, a binder, and a first component.
  • the first component includes Li 1-x1 Ti 1-x1 A x1 OPO 4 , Li 1-x1 Ti 1-x1 A x1 PO 5 , Li 2-y1 Ti 1-y1 A y1 OM1O 4 , Li 2-y1 At least one of Ti 1-y1 A y1 M1O 5 .
  • A includes at least one of Nb, Ta, and Sb, and M1 is at least one of Si and Ge.
  • the first component is at least one of LiTiOPO 4 , Li 0.9 Nb 0.1 Ti 0.9 OPO 4 , Li 0.9 Ta 0.1 Ti 0.9 OPO 4 , Li 2 TiOSiO 4 , and LiTaOGeO 4 .
  • the positive electrode material layer further includes a second component selected from LiM2 2 (PO 4 ) 3 , Li 1+x2 Al x2 M2 2x2 (PO 4 ) 3 , M2O 2 , Li 16-4y2 M2 y2 O 8. At least one or more combinations of M2P 2 O 7 , M3PO 4 , M3 2 SiO 5 , M4 3 (PO 4 ) 2 , M4 2 SiO 4 , wherein M2 is selected from Ti, Ge, Zr and Hf One, where 0 ⁇ x2 ⁇ 0.6, M3 and M4 are one of Al, Ga, Sc, Y, Ca, Sr, Zn, Si, In, Lu, La, Fe, Cr, Ge, 3 ⁇ y2 ⁇ 4.
  • the second component is preferably InPO 4 , LATP, AlPO 4 , LAGP, LATP+AlPO 4 , LAGP+Al 2 SiO 5 , InPO 4 +LATP, Al 2 SiO 5 , TiO 2 +LiTi 2 (PO 4 ) 3 , one of TiP 2 O 7 +LiGe 2 (PO 4 ) 3 .
  • the form of mixed components composed of the first component and the second component may be that the particles of the first component and the particles of the second component are uniformly mixed, or that each primary particle contains crystals of the first component. type and the second component crystal form.
  • the mass ratio of the first component to the positive electrode active material in the positive electrode material layer is w 1 , 0 ⁇ w 1 ⁇ 5%, preferably 0.1 ⁇ w 1 ⁇ 3%.
  • the mass ratio of the second component to the positive electrode active material in the positive electrode material layer is w 2 , 0 ⁇ w 2 ⁇ 5%, preferably 0 ⁇ w 1 ⁇ 3%.
  • the particle size of the first component is 10 nm-10 ⁇ m.
  • the particle size of the first component is 50nm-500nm.
  • the particle size of the second component is 10 nm-10 ⁇ m.
  • the particle size of the second component is 50nm-500nm.
  • the content of the positive electrode active material particles is 80-99wt%
  • the content of the conductive agent is 0.1-8wt%
  • the content of the binder is 0.1-10wt%
  • the content of the first component or the mixed component composed of the first component and the second component is 0.1-6wt%;
  • the positive electrode active material particles are selected from the group consisting of lithium cobaltate positive electrode and its modified material, NCM ternary positive electrode and its modified material, NCA ternary positive electrode and its modified material, lithium nickel manganese oxide positive electrode and its modified material. At least one of materials, lithium-rich positive electrodes and their modified materials, lithium iron phosphate positive electrodes and their modified materials;
  • the conductive agent is selected from at least one of Super-P, KS-6, carbon black, carbon nanofibers, carbon nanotubes, acetylene black or graphene;
  • the binder is selected from polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polytetrafluoroethylene, homopolymers, copolymers, modified compounds of the above polymers, or the above polymers and other polymers or Mixture of small molecules.
  • the second object of the present invention is to provide one of the objects of the present invention for the preparation of positive electrode sheets for lithium batteries, the first component or the mixed components of the first component and the second component are in the homogenization process blended into the positive electrode slurry. During the preparation of the positive electrode sheet, the first component or the mixed component of the first component and the second component is added, And make it dispersed among the positive electrode active material particles.
  • the preparation method comprises the following steps:
  • Step 1 uniformly mixing the first component or the mixed component of the first component and the second component, positive electrode active material, conductive additive, binder and solvent to form a slurry;
  • Step 2 Coating the slurry obtained in Step 1 on the surface of the aluminum current collector to form a positive pole piece;
  • Step 3 Blast-dry the pole piece obtained in Step 2, and then vacuum-dry it to obtain the final positive pole piece.
  • step 1 NMP is selected as the solvent in the slurry, and the mass ratio of NMP:positive electrode material is (2000-10):100.
  • step two In step two,
  • the prepared slurry used has a viscosity value of 3500-8500 mPa ⁇ S at 25°C.
  • step three In step three,
  • the blast drying temperature is 80-180°C, and the time is 10 minutes-9 hours, and the vacuum drying temperature is 80-180°C, and the time is 3-100 hours.
  • the third object of the present invention is to provide the application of the positive electrode sheet described in one of the objects of the present invention in lithium batteries.
  • the invention improves the rate performance of the battery by adding the first component or the mixed component of the first component and the second component with a particle diameter D50 of 0.01-10 ⁇ m in the positive electrode sheet, and cooperates with the conductive agent and the binder , cycle performance and safety performance, so that the battery has the characteristics of high rate, long cycle and high safety.
  • the first component in this application is usually the impurity phase that appears during the sintering process of the solid electrolyte.
  • the existence of the impurity phase generally reduces the ionic conductance of the solid electrolyte, and usually needs to be removed when preparing the solid electrolyte.
  • Now Existing technologies do not actively introduce the first component into the electrolyte in high-safety, high-rate lithium batteries.
  • the performance of the first component in this application is completely different from that of solid electrolytes.
  • the ionic conductance of such components is relatively low, which is far less than that of common solid electrolytes, which is about 10 -4 S/cm (that is, it cannot be replaced by solid electrolytes to add In the electrode material), the ionic conductance of the electrolyte is less than about 10 -2 S/cm.
  • the first component cannot directly contribute to the ion conductivity after being mixed with the electrolyte, but the first component is due to its specific properties when added to the positive electrode material.
  • the chemical composition can participate in the formation of CEI on the surface of the positive electrode material, changing the composition of CEI to make it more stable, avoiding the rupture of CEI and the resulting battery polarization and thermal runaway, and then improving the rate performance of the positive electrode sheet in the actual operation of the battery , cycle performance and safety; at the same time, we also found that when the second component is added to the mixed positive electrode, it can inhibit the decomposition of the electrolyte and inhibit its generation of insulating components on the surface of the positive electrode material, that is, when the second component is mixed with the first component at the same time When used, it can play a synergistic effect, construct a CEI with advantages, and comprehensively improve the electrical performance and safety performance of the battery.
  • the first component or the mixed component of the first component and the second group is introduced into the positive electrode by blending, which can not change the current mainstream production process of positive electrode sheets, separators and batteries, and has high stability and low cost. advantage, suitable for large-scale applications.
  • the present invention has the following advantages and outstanding effects:
  • the first component or the mixed component particles of the first component and the second component added to the positive electrode sheet of the lithium battery of the present invention have high chemical stability, and can be directly blended in the positive electrode active material before the positive electrode sheet is prepared without changing
  • the current mainstream preparation process of positive electrode, diaphragm and battery is compatible with the mainstream preparation process of the existing lithium-ion battery positive electrode, does not affect the preparation process of positive electrode and battery cell, has the advantages of high stability and low cost, and is suitable for large-scale application.
  • the method of doping the positive electrode material or coating the surface of the positive electrode needs to change the existing preparation technology of the positive electrode material, and it is difficult to improve the discharge specific capacity and rate performance at the same time.
  • the first component added to the positive electrode sheet of the lithium battery of the present invention is completely different from the conventional solid electrolyte, and its lithium ion conductivity is not strong, so it is not suitable for solid electrolyte materials at all.
  • additive components with high lithium ion conductivity are usually selected.
  • we creatively added low lithium-ion conductive When the first component reaches the positive electrode, the CEI of the positive electrode surface can be improved to significantly improve the rate performance, cycle performance and safety of the battery, which overcomes the prejudice of the existing technology.
  • the mixed component particles of the first component and the second component added to the positive electrode sheet of the lithium battery of the present invention can improve the stability of the CEI on the surface of the positive electrode particles, inhibit the release of oxygen from the positive electrode and the reaction with the electrolyte during thermal runaway, Inhibit the decomposition of the electrolyte, thereby improving the electrical performance and safety performance of the battery; experiments have shown that when the first component and the second component are used at the same time, the synergistic effect is better.
  • the content of the first component or the mixed component particles of the first component and the second component added in the positive electrode sheet of the lithium battery of the present invention is specially designed, if the content is less than 0.1wt%, it is difficult to form an effective CEI layer , the improvement of electrical performance and safety performance is not obvious. If the content is greater than 6wt%, the content of inactive substances in the battery will increase, which will reduce the energy density of the battery.
  • the prepared cathode exhibits excellent rate capability, cycle performance, and safety.
  • Fig. 1 is the schematic structural view of the lithium battery positive electrode sheet in embodiment 2;
  • Fig. 2 is the structural representation of the lithium battery cathode sheet in embodiment 1;
  • Fig. 3 is a schematic diagram of the lithium battery weight impact test tooling of the present invention.
  • FIG. 4 is a schematic structural view of the positive electrode sheet of the lithium battery in Example 11.
  • Step 1 Mix 1 kg of the first component LiTiOPO 4 and the second component Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 mixed component, 100 kg of positive electrode active material NCM90, 1 kg of Super P, 1 kg of PVDF and 500 kg of NMP solvent Mix evenly to form a slurry;
  • Step 2 Coating the slurry obtained in Step 1 on the surface of the aluminum current collector to form a positive pole piece;
  • Step 3 The electrode sheet obtained in step 2 was baked at 95°C for 5 minutes, rolled at 28T, and die-cut to obtain a positive electrode sheet with a layer thickness of 126 ⁇ m.
  • the positive electrode sheet was vacuum-dried at 105°C for 24 hours to obtain the final positive electrode sheet.
  • the content ratio of the first component and the second component is 1:4, and the particle diameters D50 of the first component and the second component are respectively 200nm.
  • the positive electrode sheet for lithium batteries prepared by the above method has a schematic structure as shown in Figure 2, including a positive electrode material layer and a current collector 3, and the positive electrode material layer includes a positive electrode active material 1, a conductive agent, a binder, a first component 2.
  • the second component 4, the first component 2 and the second component 4 in the positive electrode material layer are dispersed among the positive electrode active material 1 particles.
  • the positive electrode sheet was matched with the SiOC650 negative electrode to assemble a soft-packed lithium battery, and the lithium battery prepared above was subjected to steps such as liquid injection, formation, and capacity separation, and then electrochemical tests and safety performance tests were performed respectively.
  • the specific electrochemical performance test results are shown in Table 1, and the safety performance test results are shown in Table 2.
  • lithium battery electrochemical performance test method used in this application document is as follows:
  • the battery is charged at 0.1C, 0.2C, 0.33C, 1C, 2C, and 3C rates to the end-of-charge voltage, and then transferred to the same rate and discharged to the end-of-discharge voltage, and the same rate is cycled 4 times ;
  • Lithium-ion battery safety performance test method
  • the pouch battery is only subjected to an impact test on the wide surface, and one sample is only subjected to an impact test
  • Example 1 The schematic diagram of the structure of the prepared lithium battery positive electrode sheet is shown in Figure 1, including a positive electrode material layer and a current collector 3, and the positive electrode material layer includes a positive electrode active material 1, a conductive agent, a binder, and a first component 2.
  • the first component 2 in the positive electrode material layer is dispersed among the particles of the positive electrode active material 1 .
  • Electrochemical tests and safety performance tests were carried out on the lithium batteries prepared above after liquid injection, formation, and capacity separation.
  • the specific electrochemical performance test results of the lithium battery prepared using the positive electrode sheet are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the second component is replaced by AlPO 4
  • the negative electrode is replaced by SiOC450
  • the battery structure is NCM83
  • other parameters are the same as in Example 1; after the steps of liquid injection, formation, and capacity separation, the lithium batteries prepared above are respectively carried out.
  • Electrochemical testing and safety performance testing The specific electrochemical performance test results of the prepared lithium battery are shown in the table 1.
  • the safety performance test results are shown in Table 2.
  • the second component is replaced by Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 , the mass ratio of Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 in the first component and the second component is 1 :8:1, the positive electrode active material is replaced by LCO, the negative electrode is replaced by SiOC450, the battery structure is LCO
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 Electrochemical tests and safety performance tests were performed on the lithium batteries prepared above after the steps of liquid injection, formation, and capacity separation. The specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 2 Replace 1 kg of the mixed component consisting of the first component and the second component with only 1 kg of the first component LiTaOGeO 4 , without the second component, and the other parameters are the same as in Example 1; the lithium battery prepared above was injected After the working steps of liquid, chemical formation, and volume separation, the electrochemical test and safety performance test are respectively carried out.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the first component was replaced by LiTaOGeO 4
  • the second component was replaced by Al 2 SiO 5
  • the positive electrode active material was replaced by NCM83
  • the battery structure was NCM83
  • the lithium battery prepared above was injected After the working steps of liquid, chemical formation, and volume separation, the electrochemical test and safety performance test are respectively carried out.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the second component is replaced by Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 , the mass ratio of Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 in the first component and the second component is 1 :8:1, the particle diameter D50 of the particles of the first component and the second component is replaced by 50nm.
  • Other parameters are the same as in Example 1; the lithium battery prepared above is subjected to steps such as liquid injection, formation, and volume separation, and then electrochemical tests and safety performance tests are performed respectively.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the second component is replaced by Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 , the ratio of the two components in the first component and the second component is replaced by 1:8:1, the first component and The particle diameter D50 of the second component particles is replaced by 500nm, which Other parameters are the same as in Example 1; the lithium battery prepared above is subjected to steps such as liquid injection, formation, and volume separation, and then electrochemical tests and safety performance tests are performed respectively.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the total amount of the mixed components composed of the first component and the second component is replaced by 0.5kg, the second component is replaced by Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 , and the first component and the second
  • the mass ratio of Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 in the two components is 1:8:1, and each primary particle of the mixed component contains the crystal form of the first component and the crystal form of the second component Type particles, the primary particle size D50 of the mixed component is 200nm.
  • the mixed form is shown in Figure 4, wherein 1 is the active substance, 2 is the mixed component of the first component and the second component in the same particle, and 3 is the current collector, and other parameters are the same as in Example 1; the above prepared After liquid injection, formation, capacity separation and other working steps, the lithium battery is subjected to electrochemical test and safety performance test respectively.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the total amount of mixed components composed of the first component and the second component is replaced by 5kg, the second component is replaced by Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 and AlPO 4 , the first component and the second group
  • the ratio of the two components is replaced by 1:8:1, and the other parameters are the same as in Example 1; after the steps of liquid injection, formation, and capacity separation, the lithium battery prepared above is subjected to electrochemical tests and safety performance tests. .
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 There is no first component, no second component, and other parameters are the same as in Example 1; the lithium battery prepared above is subjected to steps such as liquid injection, formation, and volume separation, and then electrochemical tests and safety performance tests are performed respectively.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 No first component, no second component, the positive active material is replaced by NCM83, the negative electrode is SiOC450, the battery structure is NCM83
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 No first component, no second component, the positive electrode active material is replaced by LCO, the negative electrode is SiOC450, the battery structure is LCO
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 No first component, no second component, the positive electrode active material is replaced by LFP, the negative electrode is graphite, the battery structure is LFP
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 No first component, no second component, the positive electrode active material is replaced by NCM83, the negative electrode is graphite, the battery structure is NCM83
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 2 Replace the mixed component consisting of 1kg of the first component and the second component with 1kg of Al 2 O 3 , and the other parameters are the same as in Example 1; Electrochemical tests and safety performance tests were carried out respectively.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the mixed component consisting of 1 kg of the first component and the second component was replaced by 1 kg of ZnO, the positive electrode active material was replaced by NCM83, the battery structure was NCM83
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • the lithium battery prepared above is subjected to the steps of liquid injection, formation, and volume separation, respectively, for electrochemical testing and safety performance testing.
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Example 1 Replace the mixed component consisting of 1kg of the first component and the second component with 1kg of Li 0.5 La 0.5 TiO 3 , without the second component, replace the positive electrode active material with LFP, the negative electrode with graphite, and the battery structure is LFP
  • the specific electrochemical performance test results of the prepared lithium battery are shown in Table 1, and the safety performance test results are shown in Table 2.
  • Table 1 Shown in Table 1 is the electrochemical performance data of the embodiment.
  • Example 1 and Example 7 it can be known that blending the mixed components of the first component and the second component at the same time can further improve the rate performance, cycle performance and battery performance on the basis of only blending the first component. Safety performance, because the first component and the second component can play a synergistic effect to improve CEI.
  • Example 1 and Examples 9 and 10 it can be known that the first component and the second component have the optimal particle size, and the optimization of the particle size can improve the rate performance and cycle performance of the battery.
  • the particle size is too small, the second One component or the mixed component particles composed of the first component and the second component are easy to agglomerate, the particle size is too large, the first component or the mixed component particles composed of the first component and the second component cannot be combined with the active
  • the surface of the material particles is in full contact, and the particle size is too small or too large to be conducive to the construction of a stable CEI.
  • Example 1 and Comparative Examples 11 and 12 it can be seen that there is an optimal ratio of the addition amount of the first component and the second component, and the addition amount is too low to improve the rate performance and safety performance of the battery, and the addition amount is too high. It is not conducive to the performance of higher rate performance, which may be because when the first component or the mixed component composed of the first component and the second component is too high, the particles accumulate to form a low lithium ion conduction area.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本发明公开了一种锂电池用高倍率、长循环、高安全正极片，包括集流体和位于所述集流体表面的正极材料层，所述正极材料层包括选自Li1-x1Ti1-x1Ax1OPO4、Li1-x1Ti1-x1Ax1PO5、Li2-y1Ti1-y1Ay1OM1O4、Li2-y1Ti1-y1Ay1M1O5中的至少一种的第一组分，其中0≤x1≤0.7，0≤y1≤1，A包括Nb、Ta、Sb中的至少一种，M1为Si和Ge的至少一种。所述正极材料层还可包括第二组分。正极材料层中的第一组分或第一组分与第二组分的混合组分分散在正极活性材料颗粒之间。包含所述正极的锂电池表现出优异的倍率性能、循环性能和安全性。本发明不改变当前正极片、隔膜和电池的主流制备工艺，与现有锂离子电池正极片的主流制备工艺相兼容，适合大规模应用。

Description

一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用
相关申请的交叉引用
本申请要求2022年01月30日提交的中国专利申请202210113791.3的权益，该申请的内容通过引用被合并于本文。
技术领域
本发明涉及锂电池技术领域，尤其涉及一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用。
背景技术
锂离子电池具有能量密度高、循环性能好、使用寿命长、低自放电、无记忆效应等优点，在储能、动力电池和3C电子等方面逐渐占据更大的应用市场，具有广阔的应用前景。
锂电池不断朝着能量密度提高的方向发展，以为电动汽车、数码产品等电力电子产品提供更优的续航。提高电极极片负载量和压实密度，特别是正极极片的负载量和压实密度，是提高电池能量密度的一个有效方法。但随着正极极片的负载量和压实密度的提高，正极活性物质层增厚且孔隙率降低，导致锂离子在正极极片内的传输困难，电池极化严重，电池的放电比容量和倍率性能下降，循环稳定性也降低。同时，随电池能量密度的提高，电池安全性也往往更难保证。至今尚未有一种技术能同时解决上述问题。
现有提高电池倍率性能的方法有：
正极表面掺杂：公开号为CN113224287A的发明专利申请文件公开了一种锶掺杂的三元锂离子电池正极材料(Li1-xSrx[Ni1-y-zCoyMz]O2其中，M为金属Mn和Al中的一种，0＜x≤0.1，0＜y≤1，0＜z≤1)及其制备方法和应用。通过锶金属离子掺杂取代锂位，减轻阳离子混排程度，扩展锂离子通道并稳定层状结构，有效的提高锂电池的倍率性能。在这种方法在提高倍率性能的同时，往往会给材料带来容量加速衰减的问题。
现有提高电池安全性能的方法有：
正极包覆：公开号为CN113809280A的发明专利申请文件公开了一种正极材料及其制备和应用，其通过改变烧结技术手段和运用包覆剂之间的相互作用，制备出了一款拥有近似面状包覆效果的正极材料。该方法制备的正极材料表面包覆层的覆盖范围较大，显著降低了电解液对材料颗粒的侵蚀程度，有效减小了副反应发生的概率，从而提高材料的安全性。缺点：方法工艺复杂，影响电池倍率性能。
使用电解液添加剂：公开号为CN113690490A的发明专利申请文件公开了一种亚磷酸酯类锂离子电池电解液添加剂，能够有效阻止有机溶剂的燃烧或爆炸，提高电解液自身的热稳定性，提升正极稳定性，改善电池循环的稳定性和安全性。缺点：损害电池电性能如循环性能和倍率性能。
隔膜涂胶：公开号为CN108963153B的发明专利申请文件公开了一种锂离子电池隔膜及其制备方法，其通过现在基膜层的至少一侧表面涂覆水性陶瓷浆料涂层，然后在水性陶瓷浆料涂层和/或基膜层表面涂覆由聚乙二醇、聚甲基丙烯酸甲酯复合胶层。所制备获得的锂离子电池隔膜具有良好的粘结性能，可以防止极片错位发生短路，提高电池硬度，从而大大提高电池的安全性能。缺点：损害电池 倍率性能。
现有同时提高电池电性能和安全性能的方法：
CN 108365260 B公开了一种准固态电解质，原料组成包括聚合物、陶瓷电解质、锂盐和离子液体。所述陶瓷电解质包括主相磷酸钛铝锂和杂相TiP2O7/TiO2。作为优选，所述陶瓷电解质中，杂相含量为2～7％，TiP2O7和TiO2的质量比为1.5～2.5:1。该杂相含量的陶瓷电解质制备的准固态电解质的综合性能最佳。所述特殊组成与含量的杂相具有储锂特性，可提高锂离子的传输性能，又可减少主相磷酸钛铝锂与金属锂的接触，提高与金属锂的界面稳定性。然而，该专利并未提高正极电性能和安全性能，所述方法无法与现有锂离子电池正极片的主流制备工艺相兼容，不能适应大规模应用。
CN113707880A涉及一种含有固态电解质的正极极片及其制备方法和应用，旨在提高电池的倍率性能，并提升循环性能，以及安全性能。由于正极浆料中含有的固态电解质有利于电解液在极片横向和纵向进行传输浸润，利于电解液的存储和浸润，电芯循环过程中，也利于缓解极片的膨胀，降低极片膨胀过程电解液受压被挤出的量，使电芯在经过长期循环后，极片内仍含有富足的电解液，保证锂离子的正常传输，从而可提高循环性能。然而，从实施例数据看，电池容量和安全性仅有小幅度提升，而对倍率性能的效果缺少数据支持，可见添加常规固态电解质无法达到全面提高电池电性能和安全性能的目的。
因此，仍需寻找一种步骤简单且拥有成本优势的方法，同时提高电池电性能和安全性能。
发明内容
针对上述现有技术存在的局限性，本发明提供一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用。本发明的正极片包括集流体和位于所述集流体表面的正极材料层，所述正极材料层包括正极活性材料、导电剂、粘结剂、第一组分。
所述第一组分包括Li1-x1Ti1-x1Ax1OPO4、Li1-x1Ti1-x1Ax1PO5、Li2-y1Ti1-y1Ay1OM1O4、Li2-y1Ti1-y1Ay1M1O5中的至少一种。其中0≤x1≤0.7，0≤y1≤1，A包括Nb、Ta、Sb中的至少一种，M1为Si和Ge的至少一种。
优选地，所述第一组分为LiTiOPO4、Li0.9Nb0.1Ti0.9OPO4、Li0.9Ta0.1Ti0.9OPO4、Li2TiOSiO4、LiTaOGeO4中的至少一种。
所述正极材料层还包括第二组分，第二组分选自LiM22(PO4)3、Li1+x2Alx2M22x2(PO4)3、M2O2、Li16-4y2M2y2O8、M2P2O7、M3PO4、M32SiO5、M43(PO4)2、M42SiO4中的至少一种或多种组合，其中M2选自Ti、Ge、Zr和Hf中的一种，其中0＜x2＜0.6，M3和M4为Al、Ga、Sc、Y、Ca、Sr、Zn、Si、In、Lu、La、Fe、Cr、Ge中的一种,3<y2<4。
所述第二组分优选为InPO4、LATP、AlPO4、LAGP、LATP+AlPO4、LAGP+Al2SiO5、InPO4+LATP、Al2SiO5、TiO2+LiTi2(PO4)3、TiP2O7+LiGe2(PO4)3中的一种。
所述第一组分和第二组分构成的混合组分形式可以是第一组分颗粒和第二组分颗粒之间均匀混合，也可以是每个一次颗粒中均含有第一组分晶型和第二组分晶型。
所述正极材料层中第一组分与正极活性材料的质量比为w1，0＜w1＜5％，优选为0.1＜w1＜3％。
所述正极材料层中第二组分与正极活性材料的质量比为w2，0≤w2＜5％，优选为0≤w1＜3％。
所述第一组分的粒径为10nm-10μm。优选的，所述第一组分的粒径为50nm-500nm。
所述第二组分的粒径为10nm-10μm。优选的，所述第二组分的粒径为50nm-500nm。
优选地，以所述正极材料层的重量为100％计，
所述正极活性材料颗粒的含量为80～99wt％；
所述导电剂的含量为0.1～8wt％；
所述粘结剂的含量为0.1～10wt％；
所述第一组分或第一组分和第二组分构成的混合组分的含量为0.1～6wt％；
优选地，所述正极活性材料颗粒选自钴酸锂正极及其改性材料、NCM三元正极及其改性材料、NCA三元正极及其改性材料、镍锰酸锂正极及其改性材料、富锂正极及其改性材料、磷酸铁锂正极及其改性材料中的至少一种；
所述导电剂选自Super-P、KS-6、炭黑、纳米碳纤维、碳纳米管、乙炔黑或石墨烯中的中的至少一种；
所述粘结剂选自聚偏氟乙烯、聚偏氟乙烯-六氟丙烯、聚四氟乙烯、上述聚合物的均聚物、共聚物、改性化合物、或上述聚合物和其他聚合物或小分子的混合物。
本发明的目的之二是提供本发明的目的之一的锂电池用正极片的制备方法，所述第一组分或第一组分与第二组分的混合组分是在匀浆过程中掺混进正极浆料中的。在正极片制备过程中，加入第一组分或第一组分与第二组分的混合组分， 并使其分散在正极活性材料颗粒之间。
优选地，所述制备方法包括以下步骤：
步骤一：将第一组分或第一组分与第二组分的混合组分、正极活性物质、导电添加剂、粘结剂和溶剂混合均匀，形成浆料；
步骤二：将步骤一获得的浆料涂布在铝集流体表面，形成正极极片；
步骤三：将步骤二获得的极片鼓风烘干，真空烘干，得到最终的正极极片。
优选地，
步骤一中，所述浆料中溶剂选用NMP，NMP：正极材料的质量比例为(2000-10)：100。
步骤二中，
所用制备浆料25℃时粘度值为3500-8500mPa·S。
步骤三中，
所述鼓风烘干的温度为80-180℃，时间为10分钟-9小时，真空烘干的温度为80-180℃，时间为3-100小时。
本发明的目的之三是提供本发明的目的之一所述的正极片在锂电池中的应用。
本发明通过在正极片中加入粒径D50为0.01-10μm的第一组分或第一组分与第二组分的混合组分，与导电剂和粘结剂配合，提高了电池的倍率性能、循环性能和安全性能，使电池具有高倍率、长循环、高安全特点。在现有认知中，本申请中的第一组分通常是固态电解质烧结过程中出现的杂相，杂相的存在一般会降低固态电解质的离子电导，通常需要在制备固态电解质时去除，现有技术在高安全性、高倍率锂电池中不会主动在电解质中引入第一组分。但在大量实验中，我 们发现本申请中的第一组分与固态电解质性能完全不同，这类组分离子电导较低，远远小于常见固态电解质的离子电导约10-4S/cm(即无法替换成固态电解质加入电极材料中)，更小于电解液的离子电导约10-2S/cm，第一组分与电解液混合后不能直接贡献离子传导能力，但是第一组分因加入正极材料中时其特定的化学组成可以参与正极材料表面CEI的形成，改变CEI组成使其更加稳定，避免了CEI的破裂和由此引发的电池极化和热失控，进而在电池实际工作中可以提高正极极片的倍率性能、循环性能和安全性；同时我们还发现当在混合正极中加入第二组分时可抑制电解液分解及抑制其在正极材料表面产生绝缘成分，即当第二组分与第一组分同时使用时可以发挥协同作用，构建具有优势的CEI，全面提高电池的电性能和安全性能。同时通过掺混的方式将第一组分或第一组分和第二组的混合组分份引入正极，可以不改变当前正极片、隔膜和电池的主流制备工艺，具有稳定性高、成本低的优势，适合大规模应用。
本发明相比现有技术，具有如下优点及突出性效果：
本发明的锂电池正极片中加入的第一组分或第一组分和第二组分的混合组分颗粒化学稳定性高，可以在正极片制备前直接掺混在正极活性材料当中，不改变当前正极片、隔膜和电池的主流制备工艺，与现有锂离子电池正极片的主流制备工艺相兼容，不影响正极和电芯的制备工艺，具有稳定性高、成本低的优势，适合大规模应用。相比之下，正极材料掺杂或正极表面包覆的方法都需要改变现有正极材料制备技术，难以同时提高放电比容量和倍率性能。
本发明的锂电池正极片中加入的第一组分和常规固态电解质完全不同，其锂离子传导能力不强，完全不适用于固态电解质材料。现有技术为了提高电池的电性能，通常会选择高锂离子导的添加成分。然而我们创造性地加入低锂离子导的 第一组分到正极时，可以改善正极表面CEI来显著提高电池的倍率性能、循环性能和安全性，克服了已有技术偏见。本发明的锂电池正极片中同时加入的第一组分和第二组分的混合组分颗粒可以提高正极颗粒表面CEI的稳定性，抑制热失控时正极的氧气释放及与电解液的反应，抑制电解液分解，从而提高电池的电性能和安全性能；实验证明同时使用第一组分和第二组分时因协同作用效果更佳。
本发明的锂电池正极片中加入的第一组分或第一组分和第二组分的混合组分颗粒的含量是经过特殊设计的，若含量小于0.1wt％，难以形成有效的CEI层，电性能和安全性能提升不明显。若含量大于6wt％，电池内非活性物质的含量提高，会降低电池的能量密度。制备的正极表现出优异的倍率性能、循环性能和安全性。
附图说明
图1为实施例2中的锂电池正极片的结构示意图；
图2为实施例1中的锂电池正极片的结构示意图；
图3为本发明锂电池重物冲击试验工装示意图；
图4为实施例11中的锂电池正极片的结构示意图。
具体实施方式
下面结合具体附图及实施例对本发明进行具体的描述，有必要在此指出的是以下实施例只用于对本发明的进一步说明，不能理解为对本发明保护范围的限制，本领域技术人员根据本发明内容对本发明做出的一些非本质的改进和调整仍属本发明的保护范围。
实施例1
步骤一：将1kg含第一组分LiTiOPO4和第二组分Li1.4Al0.4Ti1.6(PO4)3构成的混合组分、100kg正极活性物质NCM90、1kg Super P、1kg PVDF和500kg NMP溶剂混合均匀，形成浆料；
步骤二：将步骤一获得的浆料涂布在铝集流体表面，形成正极极片；
步骤三：步骤二获得的极片经过95℃烘烤5min、28T辊压、模切得到层厚度为126μm厚的正极片，正极片经105℃真空烘干24小时得到最终的正极片。
第一组分和第二组分含量比为1:4，第一组分和第二组分的颗粒粒径D50分别为200nm。
经上述方法制备的锂电池用正极片，结构示意图如图2所示，包括正极材料层和集流体3，所述正极材料层包括正极活性材料1、导电剂、粘结剂、第一组分2、第二组分4，正极材料层中的第一组分2和第二组分4分散在正极活性材料1颗粒之间。使用该正极片与SiOC650负极匹配组装软包锂电池，将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。具体电化学性能测试结果见表1，安全性能测试结果见表2。
其中本申请文件中所使用的锂电池电化学性能测试方法如下：
1.循环性能测试
a)在23℃±2℃，以1C恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电，静置1h；
b)电池以1C恒流放电，直至达到放电终止电压，停止放电，记录放电容量；至此完成一个周次的循环；
c)重复a、b步骤，直至放电容量低于第一周放电容量的80％，记录此时电池循环的总周数。
2.倍率测试
a)在23℃±2℃电池分别以0.1C，0.2C，0.33C，1C，2C，3C倍率充电至充电终止电压后转为同倍率电流放电至放电终止电压，同种倍率均循环4次；
b)记录不同倍率下放电容量情况；
c)计算2C或3C放电容量与0.33C放电容量的比值，记为2C/0.33C或3C/0.33C,评估倍率性能。
3.高温循环
a)在45℃下以1C电流恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电；
b)电池在45℃下静置5h；
c)高温45℃条件下电池以1C电流恒流放电，直至达到放电终止电压，停止放电，记录放电容量；至此完成一个周次的循环；
d)重复a～c步骤，直至放电容量低于第一周放电容量的80％，记录此时电池的放电容量和循环的总周数。
锂离子电池安全性能测试方法：
1.过充
a)在23℃±2℃，以1C恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电，静置1h；
b)以1C持续恒流充电，直至电池发生热失控,记录开始发生热失控时电池的电压值。
2.热箱
a)在23℃±2℃，以1C恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电，静置1h；
b)将电池放入试验箱中。试验箱以5℃/min的温升速率进行升温，当箱内温度达到160℃±2℃后恒温，并持续1h；
电池不冒烟、不起火、不爆炸即为通过，否则不通过。
3.跌落
a)在23℃±2℃，以1C恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电，静置1h；
b)按1m的跌落高度自由落体跌落于混凝土板上；
软包电池每个面各跌落一次，共进行六次试验；
六次实验后，电池不冒烟、不起火、不爆炸即为通过，否则不通过。
4.重物冲击
a)在23℃±2℃，以1C恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电，静置1h；
b)将电池8置于平台表面，将直径为15.8mm±0.2mm的金属棒9横置在电池几何中心上表面，采用质量为9.1kg±0.1kg的重物从610mm±25mm的高处自由落体状态撞击放有金属棒的电池表面，并观察6h，重物冲击试验工装示意图如图3，其中5为牵引绳，6是引导管，7为钢铁冲击箱(合页门未示出)。
要求软包电池只对宽面进行冲击试验，一个样品只做一次冲击试验；
电池不冒烟、不起火、不爆炸即为通过，否则不通过。
5.针刺
a)在23℃±2℃，以1C恒流充电，直至达到充电终止电压，然后转为恒压充电，直至充电电流倍率降至0.05C，停止充电，静置1h；
b)用φ8mm的耐高温钢针(针尖的圆锥角度为45°，针的表面光洁、无锈蚀、氧化层及油污)，以25mm/s的速度，从垂直于电池极板的方向贯穿，贯穿位置为所刺面的几何中心，钢针停留在蓄电池中；
c)观察1h；
电池不冒烟、不起火、不爆炸即为通过，否则不通过。
实施例2
将1kg第一组份和第二组分构成的混合组分替换为仅含有1kg第一组分，无第二组分，正极活性物质替换为NCM83，电池结构是NCM83||SiOC650，其他参数同实施例1；所制备的锂电池正极片结构示意图如图1所示，包括正极材料层和集流体3，所述正极材料层包括正极活性材料1、导电剂、粘结剂、第一组分2，正极材料层中的第一组分2分散在正极活性材料1颗粒之间。将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。使用该正极片制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例3
第二组分替换为AlPO4，负极替换为SiOC450，电池结构是NCM83||SiOC450，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表 1，安全性能测试结果见表2。
实施例4
第二组分替换为Li1.4Al0.4Ti1.6(PO4)3和AlPO4，第一组分和第二组分中Li1.4Al0.4Ti1.6(PO4)3和AlPO4的质量比为1:8:1，正极活性物质替换为LCO，负极替换为SiOC450，电池结构是LCO||SiOC450，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例5
将1kg由第一组分和第二组分构成的混合组分替换为仅含有1kg第一组分LiTaOSiO4，无第二组分，正极活性物质替换为LFP，负极替换为石墨，电池结构是石墨||LFP，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例6
第一组分替换为LiTaOSiO4，第二组分替换为Li1.4Al0.4Ge1.6(PO4)3，正极活性物质替换为NCM83，负极替换为石墨，电池结构是石墨||NCM83，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例7
将1kg由第一组分和第二组分构成的混合组分替换为仅含有1kg第一组分LiTaOGeO4，无第二组分，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例8
第一组分替换为LiTaOGeO4，第二组分替换为Al2SiO5，正极活性物质替换为NCM83，电池结构是NCM83||SiOC650，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例9
第二组分替换为Li1.4Al0.4Ti1.6(PO4)3和AlPO4，第一组分和第二组分中Li1.4Al0.4Ti1.6(PO4)3和AlPO4的质量比为1:8:1，第一组分和第二组分颗粒的粒径D50替换为50nm。其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例10
第二组分替换为Li1.4Al0.4Ti1.6(PO4)3和AlPO4，第一组分和第二组分中两种组分的比例替换为1:8:1，第一组分和第二组分颗粒的粒径D50替换为500nm，其 他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例11
将第一组分和第二组分构成的混合组分总量替换为0.5kg，第二组分替换为Li1.4Al0.4Ti1.6(PO4)3和AlPO4，且第一组分和第二组分中Li1.4Al0.4Ti1.6(PO4)3和AlPO4质量比为1:8:1，混合组分的每个一次颗粒中均含有第一组分晶型和第二组分晶型颗粒，混合组分的一次颗粒粒径D50为200nm。混合形式为图4所示，其中1是活性物质，2是第一组分和第二组分在同一个颗粒中的混合组分，3是集流体，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
实施例12
将第一组分和第二组分构成的混合组分总量替换为5kg，第二组分替换为Li1.4Al0.4Ti1.6(PO4)3和AlPO4，第一组分和第二组分中两种组分比例替换为1:8:1，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例1
无第一组分，无第二组分，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例2
无第一组分，无第二组分，正极活性物质替换为NCM83，电池结构是NCM83||SiOC650，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例3
无第一组分，无第二组分，正极活性物质替换为NCM83，负极是SiOC450，电池结构是NCM83||SiOC450，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例4
无第一组分，无第二组分，正极活性物质替换为LCO，负极是SiOC450，电池结构是LCO||SiOC450，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例5
无第一组分，无第二组分，正极活性物质替换为LFP，负极是石墨，电池结构是LFP||石墨，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例6
无第一组分，无第二组分，正极活性物质替换为NCM83，负极是石墨，电池结构是NCM83||石墨，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例7
将由1kg第一组分和第二组分构成的混合组分替换为1kg Al2O3，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例8
将由1kg第一组分和第二组分构成的混合组分替换为1kg ZnO，正极活性物质替换为NCM83，电池结构是NCM83||SiOC650，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例9
将由1kg第一组分和第二组分构成的混合组分替换为1kg Li1.4Al0.4Ti1.6(PO4)3，正极活性物质替换为NCM83，负极替换为SiOC450，电池结构是NCM83||SiOC450，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例10
将由1kg第一组分和第二组分构成的混合组分替换为1kg AlPO4，正极活性物质替换为LCO，负极替换为SiOC450，电池结构是LCO||SiOC450，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例11
将由1kg第一组分和第二组分构成的混合组分替换为1kg Li0.5La0.5TiO3，无第二组分，正极活性物质替换为LFP，负极替换为石墨，电池结构是LFP||石墨，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
对比例12
将由1kg第一组分和第二组分构成的混合组分替换为1kg Li7La3Zr2O12，正极活性物质替换为NCM83，负极替换为石墨，电池结构是NCM83||石墨，其他参数同实施例1；将上述制备的锂电池经注液、化成、分容等工步后，分别进行电化学测试和安全性能测试。制备的锂电池的具体电化学性能测试结果见表1，安全性能测试结果见表2。
如表1所示为实施例的电化学性能数据。
表1

如表2所示为实施例的安全性能数据。
表2

从表1和表2数据看出，在正极中掺混第一组分或第一组分与第二组分的混合组分可以显著提高电池的倍率性能、循环性能和安全性能。通过实施例5和对比例11的对比可知，在正极中掺混第一组分对提高电池倍率性能、循环性能和 安全性能的效果远远强于在正极中掺混高锂离子导的固态电解质，这是因为构建高效CEI是提高液态电池和混合固液电池的电性能和安全性能的关键。通过实施例1与实施例7的对比可知，同时掺混第一组分和第二组分的混合组分可以在只掺混第一组分的基础上进一步提高电池的倍率性能、循环性能和安全性能，这是因为第一组分和第二组分可以发挥协同作用改善CEI。通过实施例1与实施例9、10的对比可知，第一组分和第二组分存在最优的粒径，粒径的优化可以提高电池的倍率性能和循环性能，粒径过小，第一组分或第一组份和第二组分构成的混合组分颗粒容易团聚，粒径过大，第一组分或第一组分和第二组分构成的混合组分颗粒不能与活性物质颗粒表面充分接触，粒径过小过大都不利于稳定的CEI的构建。通过实施例1与对比例11、12的对比可知，第一组分和第二组分的添加量存在最优比例，添加量过低无法提高电池的倍率性能和安全性能，添加量过高也不利于更高倍率性能的发挥，这可能是因为第一组份或第一组分和第二组分构成的混合组分过高时颗粒堆积形成低锂离子传导的区域。
可以理解的是，以上实施方式仅仅是为了说明本发明的原理而采用的示例性实施方式，然而本发明并不局限于此。对于本领域内的普通技术人员而言，在不脱离本发明的精神和实质的情况下，可以做出各种变型和改进，这些变型和改进也视为本发明的保护范围。

Claims (8)

  1. 一种锂电池正极片，所述正极片包括正极材料层，所述正极材料层包括正极活性材料、导电剂、粘结剂、第一组分，其特征在于：
    所述第一组分包括Li1-x1Ti1-x1Ax1OPO4、Li1-x1Ti1-x1Ax1PO5、Li2-y1Ti1-y1Ay1OM1O4、Li2-y1Ti1-y1Ay1M1O5中的至少一种，其中0≤x1≤0.7，0≤y1≤1，A包括Nb、Ta、Sb中的至少一种，M1为Si和Ge的至少一种；
    所述第一组分优选为LiTiOPO4、Li0.9Nb0.1Ti0.9OPO4、Li0.9Ta0.1Ti0.9OPO4、Li2TiOSiO4、LiTaOGeO4中的至少一种。
  2. 根据权利要求1所述的锂电池正极片，其特征在于：
    所述正极材料层还包括第二组分，第二组分选自LiM22(PO4)3、Li1+x2Alx2M22 x2(PO4)3、M2O2、Li16-4y2M2y2O8、M2P2O7、M3PO4、M32SiO5、M43(PO4)2、M42SiO4中的至少一种或多种组合，其中M2选自Ti、Ge、Zr和Hf中的一种，其中0＜x2＜0.6，M3和M4独立选自Al、Ga、Sc、Y、Ca、Sr、Zn、Si、In、Lu、La、Fe、Cr、Ge中的任一种，3<y2<4；
    所述第二组分优选为InPO4、LATP、AlPO4、LAGP、LATP+AlPO4、LAGP+Al2SiO5、InPO4+LATP、Al2SiO5、TiO2+LiTi2(PO4)3、TiP2O7+LiGe2(PO4)3中的一种。
  3. 根据权利要求1所述的正极片，其特征在于：
    所述第一组分和第二组分构成的混合组分形式，可以是第一组分颗粒和第二组分颗粒之间均匀混合，也可以是每个一次颗粒中均含有第一组分晶型和第二组分晶型。
  4. 根据权利要求1所述的锂电池正极片，其特征在于：
    所述正极材料层中第一组分与正极活性材料的质量比为w1，0＜w1＜5％，优选为0.1＜w1＜3％；第一组分的粒径为10nm-10μm，优选为50nm-500nm。
  5. 根据权利要求2所述的锂电池正极片，其特征在于：
    第二组分与正极活性材料的质量比为w2，0≤w2＜5％，优选为0≤w2＜3％；第二组分的粒径为10nm-10μm，优选为50nm-500nm。
  6. 根据权利要求1所述的锂电池正极片，其特征在于：
    所述正极活性材料包括钴酸锂正极及其改性材料、NCM三元正极及其改性材料、NCA三元正极及其改性材料、镍锰酸锂正极及其改性材料、富锂正极及其改性材料、磷酸铁锂正极及其改性材料中的至少一种。
  7. 一种权利要求1-5中任一项所述的锂电池正极片的制备方法，其特征在于：该制备方法包括如下步骤，
    步骤一：将第一组分或第一组分与第二组分的混合组分、正极活性物质、导电添加剂、粘结剂和溶剂混合均匀，形成浆料；
    步骤二：将步骤一获得的浆料涂布在铝集流体表面，形成正极极片；
    步骤三：将步骤二获得的正极极片鼓风烘干，真空烘干，得到最终的正极极片。
  8. 一种锂电池电芯，其特征在于：
    所述锂电池电芯包括正极片、负极片、隔膜、电解液和外壳，所述正极片为权利要求1-5中任一项所述的正极片。
PCT/CN2023/073560 2022-01-30 2023-01-28 一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用 WO2023143516A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210113791.3A CN116565203A (zh) 2022-01-30 2022-01-30 一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用
CN202210113791.3 2022-01-30

Publications (1)

Publication Number Publication Date
WO2023143516A1 true WO2023143516A1 (zh) 2023-08-03

Family

ID=87470666

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/073560 WO2023143516A1 (zh) 2022-01-30 2023-01-28 一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用

Country Status (2)

Country Link
CN (1) CN116565203A (zh)
WO (1) WO2023143516A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117012957A (zh) * 2023-10-08 2023-11-07 深圳市贝特瑞新能源技术研究院有限公司 耐低温磷酸铁锂半固态电池及其正极浆料和制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113745455A (zh) * 2020-05-27 2021-12-03 北京卫蓝新能源科技有限公司 兼具高安全、高容量和长循环的锂电池用三元正极片及其制备方法和用途
CN113745638A (zh) * 2020-05-27 2021-12-03 北京卫蓝新能源科技有限公司 兼具高安全、高功率的锂电池用三元正极片及其制备方法和用途
US20220328809A1 (en) * 2021-04-02 2022-10-13 Samsung Sdi Co., Ltd. Composite cathode active material for all-solid-state battery, preparation method thereof, cathode layer for all-solid-state battery, and all-solid-state battery including the cathode layer
CN115377485A (zh) * 2022-10-26 2022-11-22 江苏蓝固新能源科技有限公司 磷酸盐材料和锂离子电池
CN115557483A (zh) * 2022-09-26 2023-01-03 乐清市固态电池研究院 Latp电解质粉末制备方法、电解质片及全固态电池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113745455A (zh) * 2020-05-27 2021-12-03 北京卫蓝新能源科技有限公司 兼具高安全、高容量和长循环的锂电池用三元正极片及其制备方法和用途
CN113745638A (zh) * 2020-05-27 2021-12-03 北京卫蓝新能源科技有限公司 兼具高安全、高功率的锂电池用三元正极片及其制备方法和用途
US20220328809A1 (en) * 2021-04-02 2022-10-13 Samsung Sdi Co., Ltd. Composite cathode active material for all-solid-state battery, preparation method thereof, cathode layer for all-solid-state battery, and all-solid-state battery including the cathode layer
CN115557483A (zh) * 2022-09-26 2023-01-03 乐清市固态电池研究院 Latp电解质粉末制备方法、电解质片及全固态电池
CN115377485A (zh) * 2022-10-26 2022-11-22 江苏蓝固新能源科技有限公司 磷酸盐材料和锂离子电池

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
HOFMANN PATRICK, ARIAI JAMA, ZAICHENKO ALEKSANDR, JANEK JÜRGEN, MOLLENHAUER DOREEN, ZEIER WOLFGANG G.: "Structural analysis and electrical characterization of cation-substituted lithium ion conductors Li1−Ti1−xMxOPO4 (M = Nb, Ta, Sb)", SOLID STATE IONICS, NORTH HOLLAND PUB. COMPANY. AMSTERDAM; NL, NL, vol. 319, 1 June 2018 (2018-06-01), NL , pages 170 - 179, XP093082033, ISSN: 0167-2738, DOI: 10.1016/j.ssi.2018.01.049 *
HUPFER THOMAS; BUCHARSKY E.C.; SCHELL K.G.; HOFFMANN M.J.: "Influence of the secondary phase LiTiOPO4on the properties of Li1 + xAlxTi2 - x(PO4)3(x=0; 0.3)", SOLID STATE IONICS, NORTH HOLLAND PUB. COMPANY. AMSTERDAM; NL, NL, vol. 302, 1 January 1900 (1900-01-01), NL , pages 49 - 53, XP029942670, ISSN: 0167-2738, DOI: 10.1016/j.ssi.2016.10.008 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117012957A (zh) * 2023-10-08 2023-11-07 深圳市贝特瑞新能源技术研究院有限公司 耐低温磷酸铁锂半固态电池及其正极浆料和制备方法
CN117012957B (zh) * 2023-10-08 2024-01-19 深圳市贝特瑞新能源技术研究院有限公司 耐低温磷酸铁锂半固态电池及其正极浆料和制备方法

Also Published As

Publication number Publication date
CN116565203A (zh) 2023-08-08

Similar Documents

Publication Publication Date Title
US20210351395A1 (en) Cathode additive and preparation method therefor, cathode electrode and preparation method therefor, and lithium ion battery
CN111916665A (zh) 一种正极片及包括该正极片的锂离子电池
US11799070B2 (en) Negative electrode active material for lithium secondary battery, method of preparing the same, and negative electrode for lithium secondary battery and lithium secondary battery including the same
JP2000215884A (ja) 非水電解質電池用正極及びその製造方法、ならびこの正極を用いた非水電解質電池及びその製造方法
JP3598153B2 (ja) 非水電解質二次電池
US20210328217A1 (en) Lithium battery and anode material thereof
CN111602274A (zh) 锂二次电池用负极活性材料以及包含其的锂二次电池用负极和锂二次电池
CN113745638A (zh) 兼具高安全、高功率的锂电池用三元正极片及其制备方法和用途
JP2012146590A (ja) 非水電解質二次電池用正極、その正極の製造方法、及び非水電解質二次電池
CN112635752B (zh) 三元正极材料及其制备方法、锂电池
JP2013506960A (ja) 大出力リチウムイオン電池のためのアノード材料
CN112219293A (zh) 锂二次电池用负极和包含该锂二次电池用负极的锂二次电池
WO2023174301A1 (zh) 锂电池无机固态电解质层和锂电池用复合负极片及其制备方法和锂电池
WO2023174299A1 (zh) 一种锂电池用负极片及其制备方法和应用
JP2001076727A (ja) 非水電解質電池用正極活物質及び非水電解質電池
JP2013114848A (ja) リチウムイオン二次電池とその製造方法
JP2011249293A (ja) リチウム遷移金属化合物及びその製造方法、並びにリチウムイオン電池
JP2023531266A (ja) 正極板及び電池
JP3579280B2 (ja) 非水電解液二次電池用負極およびこの負極を備えた非水電解液二次電池
JP3440638B2 (ja) 非水電解液二次電池
WO2023143516A1 (zh) 一种高倍率、长循环、高安全锂电池用正极片及其制备方法和应用
WO2016104024A1 (ja) リチウムイオン電池
JP2012089464A (ja) 非水電解質二次電池及び非水電解質二次電池の製造方法
CN116097463A (zh) 负极和包含所述负极的二次电池
JP5890715B2 (ja) 非水電解質二次電池用正極及び非水電解質二次電池

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23746393

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023746393

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2023746393

Country of ref document: EP

Effective date: 20240610