CN107046125B - Composite negative electrode, preparation method thereof and lithium ion battery - Google Patents
Composite negative electrode, preparation method thereof and lithium ion battery Download PDFInfo
- Publication number
- CN107046125B CN107046125B CN201710097657.8A CN201710097657A CN107046125B CN 107046125 B CN107046125 B CN 107046125B CN 201710097657 A CN201710097657 A CN 201710097657A CN 107046125 B CN107046125 B CN 107046125B
- Authority
- CN
- China
- Prior art keywords
- silicon
- sio
- negative electrode
- ratio
- carbon composite
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
Images
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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/364—Composites as mixtures
-
- 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
- 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
-
- 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
- H01M4/139—Processes of manufacture
-
- 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
-
- 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
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
-
- 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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- 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
Abstract
The invention relates to a composite cathode, which comprises a cathode active material, wherein the cathode active material comprises secondary granulated graphite and SiOxC, wherein 0<x≤1，SiOxThe median particle diameter D50 of the particles/C is 1.5-6.8 μm, the median particle diameter D50 of the secondary granulated graphite is 12.0-19.6 μm, and SiOxThe median particle diameter D50 ratio of the/C and the secondary granulated graphite is 0.06-0.4, the mass ratio is 0-20%, and the compacted density of the composite negative electrode is 1.45-1.70 g/cm3The crystal alignment ratio is 4 to 15. The invention also relates to a preparation method of the composite cathode and a lithium ion battery. The lithium ion battery prepared by the composite negative electrode has the characteristics of low expansion rate, small thickness change of the pole piece and long cycle life.
Description
Technical Field
The invention relates to the field of lithium ion battery cathode materials, in particular to a composite cathode, a preparation method thereof and a lithium ion battery with the composite cathode.
Background
With the development of mobile portable electronic products and new energy electric automobile technologies, higher and higher requirements are put forward on the development of long-endurance energy lithium ion batteries.
The theoretical lithium storage capacity of silicon reaches 4200mAh/g, which is 10 times more than that of graphite material (the theoretical capacity is 372 mAh/g). The content of silicon on the earth is rich, and the silicon becomes one of the options with potential for upgrading and updating carbon-based cathodes of lithium ion batteries, and is the novel lithium ion battery cathode material with the most development potential. However, silicon is a semiconductor material, has low self conductivity, has large volume expansion in the process of lithium intercalation and deintercalation, is easy to pulverize, and is easy to cause the shedding of electrode materials so as to lose electric contact; meanwhile, the material structure is damaged, the lithium storage capacity is reduced, and the cycle performance is seriously reduced.
In contrast to elemental silicon, the silicon monoxide (SiO) generates a fraction L i after the first intercalation of lithium2O、Li4SiO4The silicon dioxide is separated out by a skeleton network and serves as a good in-situ buffer medium, so that the volume effect of active silicon particles in the charging and discharging processes is effectively inhibited; meanwhile, the support and the dispersion silicon agglomeration are realized, the agglomeration phenomenon of the ultra-fine dispersion silicon component in the later continuous charge-discharge cycle process is avoided, and the improvement of the cycle performance is facilitated. This is the most important reason why the silicon oxide material is always considered as the next generation of negative electrode material.
However, it is the first lithium intercalation that L i is generated2O、Li4SiO4In the subsequent process, the lithium ions cannot be extracted, so that the first charge-discharge efficiency of SiO is low, and the capacity exertion is generally less than 1700mAh/g and the efficiency is lower than 78.0 percent in the case of the existing document disclosure. When the initial charge-discharge efficiency is low, a large amount of lithium ions are consumed after the initial charge and cannot return to the positive electrode when the lithium ion battery is matched with the conventional commercial positive electrode material (the initial charge-discharge efficiency is about 90% generally). Originally, the purpose of adopting a large-capacity negative electrode is to increase the total capacity of the battery, but the low first charge-discharge efficiency can seriously reduce the actual capacity of the lithium battery and limit the application of the lithium battery.
In order to solve the problem of low initial charge-discharge efficiency of SiO, manufacturers carry out pre-lithiation treatment on SiO. For example, IWSeong et al in Volume 195, Issue 18,15September 2010, Pages 6143 and 6147Journal of Power Sources published articles using a two-layer negative electrode, i.e., lithium powder coated on Cu foil, SiO coated on Cu mesh, then the two stacked together to form a two-layer negative electrode. By adopting the lithium supplementing mode, the first charge and discharge efficiency of 100 percent of SiO can be realized, but the following problems are brought: firstly, the lithium foil has extremely active chemical properties, so that the production of the lithium ion battery has extremely high requirements on the environment; secondly, the manufacturing process of the lithium ion capacitor is complex, and the use of the lithium metal, the porous current collector and other key raw materials causes the cost of the lithium ion capacitor to be high.
Chinese patent application publication No. CN105470465A discloses a pre-lithiation treatment process of a silicon-based negative electrode, which comprises the steps of homogenizing, coating, electrodepositing metal lithium by a two-step constant current pulse deposition method, DMC soaking, drying and the like. By adopting the process, the first charge-discharge efficiency of the silicon-carbon cathode is effectively improved, and the cycle life of the silicon-carbon cathode is prolonged. However, since the coated pole piece is subjected to metal lithium electrodeposition, the coating surface density needs to be controlled in order to ensure the uniform integrity of the deposition. If the areal density is high, the thickness of the slurry applied to the copper foil increases, and it becomes difficult to deposit uniform and complete lithium in a short time. In addition, in the process of lithium supplement, electrodeposition, soaking and drying treatment are additionally added, the manufacturing process is more complicated, and the manufacturing cost of the lithium ion battery is greatly increased.
In addition, although the problem of charge expansion of SiO is not so obvious compared with that of simple substance silicon, the problem that the expansion is large and the cycle performance cannot meet the use requirement still exists.
Disclosure of Invention
Based on the above, the present invention aims to provide a composite negative electrode, a corresponding preparation method and a lithium ion battery comprising the composite negative electrode, wherein the expansion rate of the charge and discharge electrode plate is reduced, the thickness variation of the electrode plate is reduced, the composite negative electrode is matched with the conventional positive electrode (such as lithium cobaltate, lithium nickel cobalt manganese oxide and lithium iron phosphate), and a high charge and discharge capacity and a long cycle life are obtained without increasing the manufacturing process cost of the battery.
A composite negative electrode comprises a negative active material, wherein the negative active material comprises secondary granulated graphite and SiOxC, wherein 0<x≤1，SiOxIn the reaction of/CThe median particle diameter D50 is 1.5-6.8 μm, the median particle diameter D50 of the secondary granulated graphite is 12.0-19.6 μm, and SiOxThe median particle diameter D50 ratio of the/C and the secondary granulated graphite is 0.06-0.4, the mass ratio is 0-20%, and the compacted density of the composite negative electrode is 1.45-1.70 g/cm3The crystal alignment ratio is 4 to 15.
In one embodiment, the secondary granulated graphite is prepared by mixing one of needle coke, pitch coke or natural spherical graphite with pitch powder, heating for granulation and graphitization.
In one embodiment, the SiOxthe/C is prepared by mixing silicon dioxide and metal silicon according to the molar ratio of 1:1, sublimating to obtain a cooled silica block, crushing the silica block to obtain silica powder, and reacting the silica powder with acetylene gas.
In one embodiment, the negative electrode active material further comprises a conductive agent, an anti-settling agent and a binder, wherein the mass ratio of the negative electrode active material to the conductive agent to the anti-settling agent to the binder is 95:1.5:1.5: 2.
A lithium ion battery comprises the composite cathode.
A method of making a composite anode, comprising:
SiO with a median particle diameter D50 of 1.5-6.8 μmxC, wherein 0<x is less than or equal to 1, and secondary granulated graphite with the median particle size D50 of 12.0-19.6 mu m is mixed according to the mass ratio of 0-20% to be used as a negative electrode active material;
mixing and uniformly dispersing a negative active material, a conductive agent, an anti-settling agent and a binder in a mass ratio of 95:1.5:1.5:2 to prepare slurry;
coating the slurry on a negative current collector, drying and pressing, wherein the compaction density is 1.45-1.70 g/cm3。
In one embodiment, SiOxthe/C was prepared as follows: mixing silicon dioxide and metal silicon at a molar ratio of 1:1, reacting at 1400 deg.C to sublimate, collecting the cooled product deposited on the substrate under 300Pa to obtain silicon oxide block, pulverizing to obtain silicon oxide powder, and introducing the silicon oxide powder into nitrogen atmosphere at 5 deg.CHeating to 800 ℃ at the speed of/min, then introducing acetylene gas for reaction to prepare SiO with the surface coated carbon content of 5%x/C。
In one of the examples, the twice-granulated graphite was prepared as follows: mixing one of needle coke, pitch coke or natural spherical graphite with pitch powder, heating, stirring, granulating, graphitizing and screening.
In one embodiment, SiOxThe ratio of the/C to the median particle diameter D50 of the secondary granulated graphite is 0.06-0.4.
In one embodiment, the crystal alignment ratio of the composite negative electrode is between 4 and 15.
Experiments prove that the lithium ion battery prepared by the composite negative electrode has the characteristics of low expansion rate, small change of the thickness of a pole piece and long cycle life.
Drawings
FIG. 1 shows SiO obtained in the preparation of a composite negative electrode in example 1 of the present inventionxScanning electron micrograph of/C.
Fig. 2 is a scanning electron microscope image of secondary granulated graphite obtained in the composite negative electrode preparation process of example 1 of the present invention.
Fig. 3 is a scanning electron microscope image of the negative active material obtained in the composite negative electrode preparation process of example 1 of the present invention.
Fig. 4 is a scanning electron microscope image of the negative active material obtained in the composite negative electrode preparation process of example 4 of the present invention.
Detailed Description
The invention provides a composite negative electrode which is made of a negative electrode active material comprising a silicon monoxide (chemical formula SiO) with the surface coated by amorphous carbonxC, wherein 0<x is less than or equal to 1, and is hereinafter referred to as SiOxand/C) and graphite with a secondary granulation structure (hereinafter referred to as secondary granulation graphite).
The compacted density of the composite negative electrode is 1.45-1.70 g/cm measured by an X-ray diffraction method3The crystal orientation ratio (OI value) of the graphite particles is 4-15, and the crystal orientation ratio is to the secondary granulated graphite in the composite negative electrodeThe area ratio obtained by integrating the peak intensities of the (004) plane and the (110) plane. SiO 2xThe median particle diameter D50 of the/C is 1.5-6.8 μm, the median particle diameter D50 of the secondary granulated graphite is 12.0-19.6 μm, the median particle diameter D50 ratio of the two is 0.06-0.4, and the mass ratio is 0-20%.
The lithium ion battery prepared by the composite negative electrode has the characteristics of low expansion rate, small change of the thickness of a pole piece and long cycle life.
Preparation of composite negative electrode
Example 1:
SiO with 3.4 μm median particle diameter D50xThe ratio of/C and secondary granulated graphite with the median particle diameter D50 of 16.8 mu m is calculated in a ratio of 10: the mixture in a weight ratio of 90 was used as a negative active material.
The SiOxthe/C was prepared as follows:
silica and metallic silicon were mixed in a molar ratio of 1:1, reacted at 1400 ℃ to sublimate, and the cooled product deposited on the substrate was collected at 300Pa to obtain a silica block, which was then pulverized with, for example, a jet mill into a silica powder having a median particle diameter D50 of 2.9 μm. Then a certain amount of silicon monoxide powder is put into a rotary furnace, the temperature is raised to 800 ℃ at the speed of 5 ℃/min under the nitrogen atmosphere, then acetylene gas is introduced, the flow and the reaction time are controlled, and the SiO with the surface coating carbon content of 5 percent is preparedx/C。
As shown in FIG. 1, SiO prepared in the above mannerxScanning Electron microscopy of/C, SiOxThe average particle diameter of C was 3.4. mu.m, and the whole particles were small.
The secondary granulated graphite is prepared in the following way:
mixing needle coke and petroleum asphalt powder according to the weight ratio of 90: 10, then placing the mixture into a reaction kettle for stirring granulation, heating the mixture while stirring (400 ℃ and 600 ℃ for 1-10 hours), graphitizing the obtained material at a high temperature of more than 3000 ℃, and removing large particles through a 200-mesh screen after graphitization, wherein the obtained undersize is secondary granulated graphite with a median particle size D50 of 16.8 mu m.
As shown in fig. 2, the scanning electron micrograph of the secondarily granulated graphite prepared in the above manner showed an average particle diameter of 16.8 μm, and the whole structure was a secondary particle structure granulated as a primary particle.
As shown in FIG. 3, is SiO as shown in FIG. 1xSecond granulated graphite as shown in FIG. 2 and 10: and 90 weight ratio of the anode active material.
Mixing a negative electrode active material with a conductive agent (SP), an anti-settling agent (CMC) and a binder (SBR) together according to a mass ratio of 95:1.5:1.5:2, taking water (H2O) as a dispersion medium, and stirring at a high speed to prepare uniformly dispersed slurry with a certain viscosity.
The slurry was directly coated on the negative current collector copper foil (single side), dried and pressed. Then, the composite anode is formed by punching into a predetermined size. At 1.65g/cm3The crystal alignment ratio of the composite negative electrode is 7.2 under the compacted density.
The crystal alignment ratio can be measured by an area ratio ((004)/(110)) obtained by integrating the peak intensities of the (004) plane and the (110) plane of the negative active material substance secondary granulated graphite on the composite negative electrode sheet after pressing with an X-ray diffraction analyzer. The XRD measurement conditions were as follows:
target Cu (K α line) graphite monochromator
Measurement range and step angle/measurement time:
scanning rate: 0.082 degree/second
Scanning step length: 0.0066 degree
Scanning angle: i004 (52-56 degrees); i110(75 to 79 degree)
Example 2
A composite negative electrode was produced in substantially the same manner as in example 1, except that in the production of the graphite of secondary granulated structure, the content of binder pitch was reduced so that the ratio of needle coke to pitch powder was 95: 5, obtaining the graphite with the secondary granulation structure and the median particle diameter D50 of 14.2 mu m. At 1.65g/cm3The crystal alignment ratio of the composite negative electrode is 12.6 under the compacted density.
Example 3
A composite negative electrode was produced in substantially the same manner as in example 1, except that graphite having a secondary granulated structure was producedIn the process, the ratio of asphalt coke to asphalt powder is 85: 15, obtaining the secondary granulation structured graphite with the median particle size D50 of 16.6 mu m. At 1.65g/cm3The crystal alignment ratio of the composite negative electrode was 5.1 at the compacted density.
Example 4
A composite negative electrode was produced in substantially the same manner as in example 1, except that in the production of the graphite of secondary granulated structure, a ratio of natural spherical graphite to pitch powder of 85: 15, obtaining the graphite with the secondary granulation structure and the median diameter D50 of 18.5 mu m. As shown in fig. 4, a scanning electron micrograph of the negative active material prepared in example 4 is shown. At 1.65g/cm3The crystal alignment ratio of the composite negative electrode is 8.4 under the compacted density.
Example 5
A composite negative electrode was produced in substantially the same manner as in example 1, except that SiO was producedxIn the process of/C, the bulk of the silica was pulverized to obtain a silica powder having a median particle diameter D50 of 5.1. mu.m.
Example 6
A composite negative electrode was produced in substantially the same manner as in example 1, except that SiO was producedxIn the process of/C, the bulk of the silica was pulverized to obtain a silica powder having a median particle diameter D50 of 1.6. mu.m.
Example 7
A composite negative electrode was prepared in substantially the same manner as in example 1, except that SiO was usedxthe/C and the secondary granulated graphite are mixed in a weight ratio of 5: 95.
Example 8
A composite negative electrode was prepared in substantially the same manner as in example 1, except that SiO was usedxMixing the/C and the secondary granulated graphite in a weight ratio of 15: 85.
Example 9
A composite negative electrode was prepared in substantially the same manner as in example 1, except that SiO was usedxMixing the/C and the secondary granulation structure graphite in a weight ratio of 20: 80.
Comparative example 1
A composite anode was prepared in substantially the same manner as in example 1, except that SiO was usedxA mixture of/C and needle-like coke graphite having a median particle diameter D50 of 20 μm without binder granulation was used as a negative electrode active material. At 1.65g/cm3The crystal alignment ratio of the composite negative electrode at the compacted density was 42.43.
Comparative example 2
A composite anode was prepared in substantially the same manner as in example 1, except that SiO was usedxA mixture of/C and natural spherical graphite having a median particle diameter D50 of 18 μm without pitch binding granulation was used as a negative electrode active material. At 1.65g/cm3The crystal alignment ratio of the composite negative electrode at the compacted density was 53.64.
Comparative example 3
A composite anode was produced in substantially the same manner as in example 1, except that SiO having a median particle diameter D50 of 10 μm was usedx/C。
Comparative example 4
A composite negative electrode was prepared in substantially the same manner as in example 1, except that SiO was usedxthe/C and the secondary granulated graphite were mixed in a weight ratio of 30: 70.
Lithium ion battery preparation
The slurry prepared in examples 1 to 9 and comparative examples 1 to 4 was directly coated on a copper foil (both sides) of a negative current collector, and then dried, rolled, slit, punched and tab-welded to form a composite negative electrode sheet.
Using L iCoO2As a positive electrode active material. The positive electrode active material, SP as a conductive agent, and polyvinylidene fluoride (PVDF) as a binder were mixed at a weight ratio of 95:2:3, and then the mixture was added to an organic dispersion medium, Nitrogen Methyl Pyrrolidone (NMP), and uniformly dispersed slurry of a certain viscosity was prepared by high-speed stirring. And then directly coating the slurry on the aluminum foil (double surfaces) of the positive current collector, and then drying, rolling, slitting, blanking and tab welding to form the positive plate.
And then the composite negative pole piece, the diaphragm and the positive pole piece are sequentially stacked and manufactured into a battery cell by adopting a winding structure, and the battery cell is manufactured into the 403048 type soft package lithium ion battery after the processes of baking, shelling, liquid injection, formation, secondary sealing and capacity grading respectively.
Capacity retention rate of 300 weeks
Regarding the 300-cycle capacity retention rate of the lithium ion battery, it was defined as charging and discharging at 0.5C from the battery after the capacity division, and the ratio of the discharge capacity in the 300 th cycle to the first discharge capacity was measured. Namely, the capacity retention rate at 300 weeks is calculated as follows:
(discharge capacity in 300. sup. th cycle/first discharge capacity) × 100%
Full electric expansion rate
Regarding the full electrical expansion rate of the pole piece, the following calculation is performed: after formation, the battery is charged to 4.35V by a constant current of 0.2C and charged to 0.05C by a constant voltage of 4.35V, the thickness of the pole piece in a full-state is measured after the pole piece is disassembled, and then the thickness of the pole piece is compared with the thickness of the pole piece before the battery is assembled.
300 cycle expansion ratio
Regarding the pole piece expansion ratio, the electrode thickness was measured by disassembling the lithium ion battery in the charged state at cycle 300 and then compared with the electrode thickness before cycle 1. Namely, the expansion rate of the pole piece is calculated according to the following formula:
(electrode thickness in charged state at 300 th cycle-electrode thickness before 1 st cycle)/electrode thickness before 1 st cycle × 100%
| Numbering | Full electric expansion Rate (%) | Capacity retention at 300 weeks (%) | 300-week cycle expansion ratio (%) |
| Example 1 | 25.4 | 87.4 | 45.6 |
| Example 2 | 28.6 | 86.2 | 48.4 |
| Example 3 | 23.5 | 88.5 | 43.1 |
| Example 4 | 26.3 | 83.9 | 46.3 |
| Example 5 | 28.7 | 85.6 | 49.5 |
| Example 6 | 24.5 | 85.3 | 44.8 |
| Example 7 | 22.1 | 90.4 | 44.3 |
| Example 8 | 34.3 | 82.2 | 53.7 |
| Example 9 | 38.4 | 80.1 | 59.6 |
| Comparative example 1 | 29.5 | 75.3 | 77.3 |
| Comparative example 2 | 32.4 | 70.5 | 79.8 |
| Comparative example 3 | 33.7 | 56.7 | 85.2 |
| Comparative example 4 | 45.2 | 34.2 | 104.6 |
As can be seen from the data in the table, based on the same SiOxThe compounding ratio of/C and graphite was lower in both the full electrical expansion rate and the 300-cycle expansion rate as in examples 1 to 6 than in comparative examples 1 to 2. The low expansion rate of the pole piece can avoid the poor contact between the conductive agent SP and the adhesive SRB and the active substance and the poor contact between the adhesive SBR and the current collector copper foil caused by expansion change as much as possible, thereby avoiding the increase of internal resistance and the attenuation of circulation capacity caused by poor contact. Therefore, the composite negative electrodes obtained in examples 1 to 6 have advantages of a low expansion ratio and a high capacity retention ratio as compared with those obtained in comparative examples 1 to 2.
Based on the same orderGranulated graphite and SiO with different grain diametersxthe/C composite is superior to comparative example 3 in all of the full-electric expansion rate, 300-cycle expansion rate and capacity retention rate index as in examples 1, 5 and 6.
Based on the same SiOxThe compositions of the graphite/C and the twice-granulated graphite, which are different from those of comparative example 4 in examples 1, 7, 8 and 9, are superior in all of the full-electric expansion rate, 300-cycle expansion rate and capacity retention rate.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. The silicon-carbon composite negative electrode comprises a negative active material, and is characterized in that the negative active material comprises secondary granulated graphite and SiOxC, wherein 0<x≤1，SiOxThe median particle diameter D50 of the/C is 3.4 mu m, the median particle diameter D50 of the secondary granulated graphite is 14.2-18.5 mu m, and SiOxThe ratio of the/C to the median particle diameter D50 of the secondary granulated graphite is 0.18-0.24, and the mass ratio is 5-20 percent, namely SiOxThe ratio of the mass of the/C to the mass of the secondary granulated graphite is between 5 and 20 percent, and the compacted density of the silicon-carbon composite negative electrode is 1.65g/cm3In the range of (a), a crystal orientation ratio obtained by integrating peak intensities of a (004) plane and a (110) plane of secondary granulated graphite in the silicon-carbon composite negative electrode is 5.1 to 12.6.
2. The silicon-carbon composite negative electrode according to claim 1, wherein the secondary granulated graphite is prepared by mixing one of needle coke, pitch coke or natural spherical graphite with pitch powder, heating for granulation, and graphitizing.
3. The silicon-carbon composite anode of claim 1, wherein the SiOxthe/C is prepared by mixing silicon dioxide and metal silicon according to the molar ratio of 1:1, sublimating to obtain a cooled silica block, crushing the silica block to obtain silica powder, and reacting the silica powder with acetylene gas.
4. The silicon-carbon composite negative electrode according to claim 1, further comprising a conductive agent, an anti-settling agent and a binder, wherein the mass ratio of the negative electrode active material to the conductive agent, the anti-settling agent and the binder is 95:1.5:1.5: 2.
5. A lithium ion battery characterized by comprising the silicon-carbon composite negative electrode according to any one of claims 1 to 4.
6. A preparation method of a silicon-carbon composite negative electrode is characterized by comprising the following steps:
SiO with 3.4 μm median particle diameter D50xC, wherein 0<x is less than or equal to 1, and secondary granulated graphite with the median particle diameter D50 of 14.2-18.5 mu m is mixed by mass ratio of 5-20% as a negative active material, namely SiOxThe ratio of the mass of the/C to the mass of the secondary granulated graphite is between 5 and 20 percent, and SiO isxThe median particle size D50 ratio of the/C and the secondary granulated graphite is 0.18-0.24;
mixing and uniformly dispersing a negative active material, a conductive agent, an anti-settling agent and a binder in a mass ratio of 95:1.5:1.5:2 to prepare slurry;
coating the slurry on a negative current collector, drying and pressing, and the compacted density is 1.65g/cm3And obtaining the crystal orientation ratio of the silicon-carbon composite cathode between 5.1 and 12.6The area ratio obtained by integrating the peak intensities of the (004) plane and the (110) plane of the secondary granulated graphite in the silicon-carbon composite negative electrode.
7. The method for producing a silicon-carbon composite anode according to claim 6, wherein SiO isxthe/C was prepared as follows: mixing silicon dioxide and metal silicon according to a molar ratio of 1:1, reacting at 1400 ℃ to sublimate, collecting a cooling product deposited on a substrate under 300Pa to obtain a silicon oxide block, then crushing to obtain silicon oxide powder, heating the silicon oxide powder to 800 ℃ at a speed of 5 ℃/min under a nitrogen atmosphere, then introducing acetylene gas to react to prepare SiO with the surface coated with 5% of carbon contentx/C。
8. The method of manufacturing a silicon-carbon composite anode according to claim 6, wherein the secondary granulated graphite is manufactured as follows: mixing one of needle coke, pitch coke or natural spherical graphite with pitch powder, heating, stirring, granulating, graphitizing and screening.
9. The method for producing a silicon-carbon composite anode according to claim 6, wherein SiO isxThe ratio of/C to the median particle diameter D50 of the twice granulated graphite was 0.18, 0.20 or 0.24.
10. The method of claim 6, wherein the silicon-carbon composite anode has a crystal alignment ratio of 5.1, 7.2, 8.4, or 12.6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710097657.8A CN107046125B (en) | 2017-02-22 | 2017-02-22 | Composite negative electrode, preparation method thereof and lithium ion battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710097657.8A CN107046125B (en) | 2017-02-22 | 2017-02-22 | Composite negative electrode, preparation method thereof and lithium ion battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107046125A CN107046125A (en) | 2017-08-15 |
| CN107046125B true CN107046125B (en) | 2020-08-04 |
Family
ID=59544141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710097657.8A Active CN107046125B (en) | 2017-02-22 | 2017-02-22 | Composite negative electrode, preparation method thereof and lithium ion battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107046125B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111816849A (en) * | 2019-04-10 | 2020-10-23 | 宝武炭材料科技有限公司 | Preparation method of silicon-containing lithium ion battery negative electrode material |
| CN112420979B (en) | 2019-08-23 | 2022-02-11 | 宁德时代新能源科技股份有限公司 | Method for determining quick charging performance of negative pole piece and design method of negative pole piece |
| WO2021056266A1 (en) * | 2019-09-25 | 2021-04-01 | 福建翔丰华新能源材料有限公司 | Lithium ion battery pre-lithiated silicon-carbon multilayer composite negative electrode material and preparation method therefor |
| WO2021102847A1 (en) * | 2019-11-28 | 2021-06-03 | 宁德新能源科技有限公司 | Negative electrode material, electrochemical device comprising same, and electronic device |
| CN111403740A (en) * | 2020-03-24 | 2020-07-10 | 洛阳联创锂能科技有限公司 | Preparation method of silica ink composite material |
| CN111463424A (en) * | 2020-04-09 | 2020-07-28 | 北京蒙京石墨新材料科技研究院有限公司 | Preparation method of silica negative electrode slurry |
| HUE062084T2 (en) * | 2020-04-30 | 2023-09-28 | Contemporary Amperex Technology Co Ltd | Negative electrode active material, manufacturing method therefor, secondary battery, and device comprising secondary battery |
| CN111613791B (en) * | 2020-06-24 | 2021-08-03 | 湖南电将军新能源有限公司 | Negative electrode active material, silicon-carbon negative electrode piece and high-energy-density quick-charging lithium ion battery |
| CN111969196B (en) * | 2020-08-05 | 2023-01-10 | 有研资源环境技术研究院(北京)有限公司 | Nano flaky silicon oxide and composite negative electrode material thereof |
| CN112447956B (en) * | 2020-11-27 | 2022-07-22 | 深圳市德方纳米科技股份有限公司 | Composite silicon-based negative electrode material, preparation method thereof and lithium ion battery |
| CN112701270B (en) * | 2020-12-28 | 2022-08-05 | 宁德新能源科技有限公司 | Negative electrode material, pole piece containing negative electrode material and electrochemical device |
| CN112820869B (en) * | 2020-12-31 | 2022-11-01 | 宁德新能源科技有限公司 | Negative electrode active material, electrochemical device, and electronic device |
| CN113161521B (en) * | 2021-03-10 | 2022-11-01 | 广东海洋大学 | Natural graphite-based silicon-carbon composite negative electrode material and preparation method and application thereof |
| CN113488637B (en) * | 2021-06-18 | 2023-04-07 | 江苏正力新能电池技术有限公司 | Composite negative electrode material, negative plate and lithium ion battery |
| CN113745645B (en) * | 2021-09-08 | 2022-08-05 | 珠海冠宇电池股份有限公司 | Lithium ion battery of silicon cathode system |
| CN114883546A (en) * | 2022-05-19 | 2022-08-09 | 江苏正力新能电池技术有限公司 | Silicon-carbon composite active material, preparation method thereof, negative plate and secondary battery |
| CN116435517B (en) * | 2023-06-12 | 2023-09-05 | 蔚来电池科技(安徽)有限公司 | Negative electrode sheet, secondary battery and device comprising same |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101916844A (en) * | 2010-07-29 | 2010-12-15 | 吴壮雄 | Torispherical cathode material for lithium ion battery and preparation method thereof |
| CN102394288A (en) * | 2011-11-24 | 2012-03-28 | 深圳市贝特瑞新能源材料股份有限公司 | Silicon-carbon cathode material for lithium ion battery and manufacturing method thereof |
| CN103219504A (en) * | 2013-03-28 | 2013-07-24 | 深圳市贝特瑞新能源材料股份有限公司 | Silicon monoxide composite cathode material for lithium ion battery, and preparation method thereof |
| CN103618086A (en) * | 2013-11-21 | 2014-03-05 | 封锡胜 | Positive material of lithium ion battery |
| CN106058190A (en) * | 2016-07-19 | 2016-10-26 | 天津师范大学 | Preparation method for high-capacity anode material for lithium ion battery |
| CN106207142A (en) * | 2015-04-30 | 2016-12-07 | 深圳市比克电池有限公司 | A kind of power lithium-ion battery silicon-carbon composite cathode material preparation method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007072858A1 (en) * | 2005-12-21 | 2007-06-28 | Showa Denko K. K. | Composite graphite particles and lithium rechargeable battery using the same |
| JP5458689B2 (en) * | 2008-06-25 | 2014-04-02 | 三菱化学株式会社 | Non-aqueous secondary battery composite graphite particles, negative electrode material containing the same, negative electrode and non-aqueous secondary battery |
| JP2010272380A (en) * | 2009-05-22 | 2010-12-02 | Hitachi Ltd | Negative electrode for lithium secondary battery, and lithium secondary battery using the same |
-
2017
- 2017-02-22 CN CN201710097657.8A patent/CN107046125B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101916844A (en) * | 2010-07-29 | 2010-12-15 | 吴壮雄 | Torispherical cathode material for lithium ion battery and preparation method thereof |
| CN102394288A (en) * | 2011-11-24 | 2012-03-28 | 深圳市贝特瑞新能源材料股份有限公司 | Silicon-carbon cathode material for lithium ion battery and manufacturing method thereof |
| CN103219504A (en) * | 2013-03-28 | 2013-07-24 | 深圳市贝特瑞新能源材料股份有限公司 | Silicon monoxide composite cathode material for lithium ion battery, and preparation method thereof |
| CN103618086A (en) * | 2013-11-21 | 2014-03-05 | 封锡胜 | Positive material of lithium ion battery |
| CN106207142A (en) * | 2015-04-30 | 2016-12-07 | 深圳市比克电池有限公司 | A kind of power lithium-ion battery silicon-carbon composite cathode material preparation method |
| CN106058190A (en) * | 2016-07-19 | 2016-10-26 | 天津师范大学 | Preparation method for high-capacity anode material for lithium ion battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107046125A (en) | 2017-08-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107046125B (en) | Composite negative electrode, preparation method thereof and lithium ion battery | |
| US11791462B2 (en) | Modified silicon monoxide material for use in negative electrode of lithium-ion battery and preparation method therefor | |
| JP7436765B2 (en) | Carbon-coated lithium-rich oxide composite material and its manufacturing method | |
| WO2021057929A1 (en) | Silicon composite negative electrode material and preparation method therefor, and lithium ion battery | |
| KR101977931B1 (en) | Preparing Method of Negative Electrode Material For Lithium Secondary Battery And Lithium Secondary Battery Comprising Negative Electrode Material Formed Therefrom | |
| JP5245592B2 (en) | Negative electrode material for non-aqueous electrolyte secondary battery, lithium ion secondary battery and electrochemical capacitor | |
| KR101461220B1 (en) | Negative active material for rechargeable lithium battery, method of preparing the same, and negative electrode and rechargeable lithium battery including the same | |
| KR101368474B1 (en) | Negative active material for rechargeable lithium battery, method of preparing the same, and rechargeable lithium battery including the same | |
| JP7209089B2 (en) | Negative electrode active material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery including the same | |
| WO2014092141A1 (en) | Negative electrode material for lithium ion secondary battery, negative electrode sheet for lithium ion secondary battery, and lithium secondary battery | |
| Lin et al. | Electrochemical properties of carbon-coated Li [Ni1/3Co1/3Mn1/3] O2 cathode material for lithium-ion batteries | |
| CN109037659A (en) | A kind of preparation method of bilayer carbon-coated LiFePO 4 for lithium ion batteries material | |
| CN105340108A (en) | Conductive carbons for lithium ion batteries | |
| Zhao et al. | Double role of silicon in improving the rate performance of LiFePO4 cathode materials | |
| CN114094068B (en) | Cobalt-coated positive electrode material, preparation method thereof, positive electrode plate and lithium ion battery | |
| JP2003297353A (en) | Negative electrode for secondary battery, secondary battery using such negative electrode, and manufacturing method for negative electrode | |
| KR20190116818A (en) | Negative active material for recahrgeable lithium battery and recahrgeable lithium battery including the same | |
| CN112542587A (en) | Graphite material, secondary battery, and electronic device | |
| CN113066988B (en) | Negative pole piece and preparation method and application thereof | |
| CN116636045A (en) | Negative electrode active material for lithium secondary battery, method for preparing same, and lithium secondary battery comprising same | |
| CN111029541A (en) | Silicon-carbon composite electrode material for honeycomb-like lithium ion battery and preparation method thereof | |
| KR102176590B1 (en) | Method of preparing anode active material for rechargeable lithium battery and rechargeable lithium battery | |
| CN113097453A (en) | Lithium pre-embedding method for positive electrode of lithium ion battery | |
| WO2019159367A1 (en) | Carbonaceous particles, negative electrode material for lithium ion secondary battery, negative electrode for lithium ion secondary battery, and lithium ion secondary battery | |
| KR20160039483A (en) | Anode active material and lithium secondary battery comprising the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20201202 Address after: 610000 no.6668-179, Section 2, Qingquan Avenue, Qingbaijiang District, Chengdu City, Sichuan Province Patentee after: Sichuan jinhuineng New Material Co., Ltd Patentee after: SHENZHEN KINGRUNNING ENERGY MATERIALS Co.,Ltd. Patentee after: SICHUAN JINTAINENG NEW MATERIAL Co.,Ltd. Address before: 518000 Guangdong Province, Shenzhen city Longhua District Guanlan ring View Road high tech Industrial Park, Jinke Industrial Park B building 6 floor Patentee before: SHENZHEN KINGRUNNING ENERGY MATERIALS Co.,Ltd. |