CN111180729A - Silicon-based negative electrode material adopting different graphene for multiple coating - Google Patents
Silicon-based negative electrode material adopting different graphene for multiple coating Download PDFInfo
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Abstract
The invention provides a silicon-based negative electrode material multiply coated by different graphene, wherein the structure of the silicon-based negative electrode material comprises nano silicon particles and a graphene multiple coating layer coating the nano silicon particles, wherein the graphene multiple coating layer is composed of an inner layer of reduced graphene oxide and an outer layer containing liquid-phase stripped graphene. According to the silicon-based negative electrode material provided by the embodiment of the invention, the outer layer containing the liquid-phase exfoliated graphene is adopted to coat the reduced graphene oxide layer, and the reduced graphene oxide coating the nano silicon particles can be coated or attached to the liquid-phase exfoliated graphene like a three-dimensional strip, so that the conductivity and the mechanical property of a system are further enhanced.
Description
Technical Field
The invention belongs to the field of new energy lithium ion battery conductive paste, and particularly relates to a silicon-based negative electrode material multiply coated by different graphene.
Background
With the increasingly significant energy and environmental problems, the development of new energy and the popularization of electric tools become market-oriented, but the development of new technologies cannot depart from the development of energy storage devices, lithium ion batteries are taken as the most important energy storage devices at present, and are favored by the majority of industrial industries and researchers, a graphite material is mainly adopted as a negative electrode, no matter natural graphite or artificial graphite, the capacity of the lithium ion batteries is limited to 372mAh/g and cannot meet the current requirement, the theoretical capacity of silicon is 4200mAh/g when a Li22Si5 lithium silicon alloy is formed, the formed Li15Si4 is 3580mAh/g, the theoretical capacity of the commercial graphite negative electrode material is nearly 10 times that of the commercial graphite negative electrode material and far exceeds that of other negative electrode materials, in addition, the lithiation voltage platform (0.2-0.3V vs. Li/Li +) of a silicon negative electrode is higher than that of the graphite negative electrode (< 0.1V vs. Li +), the precipitation of lithium and the formation of lithium dendrite can be avoided, the safety of the lithium ion battery system is ensured. However, the volume change (more than 300%) of the silicon material in the charging and discharging process brings serious consequences for the application of the silicon material, including pulverization and crushing of a silicon negative electrode under the action of stress, continuous damage and regeneration of a solid electrolyte interface film (SEI film) on the surface of a material fracture part, reduction of conductivity and the like, and directly leads to rapid capacity attenuation of the silicon material in a battery system.
At present, in order to deal with the volume effect of silicon materials, silicon is coated with carbon to form a silicon-carbon composite material, but a carbon layer is rigidly connected with silicon, and because of huge volume expansion in the silicon, the carbon layer and the silicon are easily separated, and finally, a new SEI film is continuously formed and the internal structure of the silicon is unstable. And when the graphene is used as a coating material, the good flexibility and mechanical property of the graphene can effectively buffer the volume effect of the silicon material in the charging and discharging process, and meanwhile, the graphene also has excellent conductivity compared with pyrolytic carbon, so that the good electrical contact between silicon and a current collector can be better ensured. However, most of graphene is physically mixed in the coating process, so that silicon and graphene are difficult to uniformly disperse, and the coating effect is poor.
Disclosure of Invention
Based on the background technology, the silicon material is used as the lithium ion battery cathode material to improve the charge and discharge capacity, but the problem that the capacity of the silicon material in a battery system is rapidly attenuated due to the volume effect of the silicon material cannot be effectively solved, the invention provides the following silicon-based cathode material with multiple coatings of different graphene, and the problems of larger volume effect and low conductivity of the silicon material in charge and discharge cycles are expected to be improved:
the silicon-based negative electrode material adopts different graphene for multiple coating, and the structure of the silicon-based negative electrode material comprises nano silicon particles and a graphene multiple coating layer for coating the nano silicon particles, wherein the graphene multiple coating layer is composed of an inner layer for reducing and oxidizing graphene and an outer layer containing liquid-phase stripping graphene.
Optionally, the outer layer containing liquid phase exfoliated graphene is a sintered carbon layer containing liquid phase exfoliated graphene.
Optionally, the particle size D50 of the reduced graphene oxide is smaller than 2 um.
Optionally, the particle size D50 of the reduced graphene oxide is greater than 1 um.
Optionally, the particle size D50 of the liquid-phase exfoliated graphene is less than 5 um.
Optionally, the particle size D50 of the liquid-phase exfoliated graphene is larger than 3 um.
Optionally, the particle size D50 of the nano silicon particles is 50-200 nm.
Optionally, the silicon-based negative electrode material is composed of nano silicon particles, reduced graphene oxide sequentially coating the nano silicon particles, and a sintered carbon layer containing liquid-phase exfoliated graphene.
Optionally, the nano silicon particles: reducing graphene oxide: liquid-phase stripping of graphene: the weight ratio of the sintered carbon is 28-62: 2.5-10: 2.5-10: 28-62.
The preparation method of any silicon-based negative electrode material is characterized by comprising the following steps of 1) adding nano silicon particles into a graphene oxide solution for uniform dispersion, reducing and drying the graphene oxide; 2) uniformly mixing and dispersing the particles dried in the step 1), the liquid-phase stripping graphene solution and the carbon resin solution, drying and sintering.
By adopting the silicon-based negative electrode material with different graphene multiple coatings, the graphene multiple coating layer is composed of the inner layer of reduced graphene oxide and the outer layer containing liquid-phase stripped graphene, the particle size of the graphene oxide is small, the graphene oxide is dispersed stably in water, a small amount of graphene oxide can coat nano silicon particles well, but the reduced graphene oxide has more defects and the conductivity can be influenced by the defects, the outer layer containing the liquid-phase stripped graphene is used for coating the reduced graphene oxide layer, the reduced graphene oxide coating the nano silicon particles can be coated or attached to the liquid-phase stripped graphene like a three-dimensional strip, and the conductivity and the mechanical property of the system are further enhanced.
Drawings
Fig. 1 is a schematic structural diagram of a specific embodiment of a structure of a silicon-based negative electrode material multiply coated with different graphenes according to the present invention;
FIG. 2 is a graph showing a test of the pull-out property in example 1 of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, a detailed description of the present invention is provided below with reference to fig. 1.
According to the silicon-based negative electrode material adopting different graphene multiple coatings, the structure of the silicon-based negative electrode material comprises a nano silicon particle 1 and a graphene multiple coating layer coating the nano silicon particle, wherein the graphene multiple coating layer is composed of an inner layer 2 of reduced graphene oxide and an outer layer containing liquid-phase exfoliated graphene 3. As shown in fig. 1, the inner layer 2 of the reduced graphene oxide coating the nano silicon particles 1 is coated or attached to the liquid-phase exfoliated graphene 3 like a three-dimensional strip, so that the defects of the reduced graphene oxide are overcome, the electrical contact between the inner layers 2 of the reduced graphene oxide coating the nano silicon particles 1 is increased, and the mechanical property and the electrical conductivity of the system are enhanced. The composition content of the liquid-phase exfoliated graphene 3 and the redox graphene can be selected according to actual conditions, and in a specific embodiment of the invention, the weight ratio of the liquid-phase exfoliated graphene 3 to the redox graphene is 1:2-2: 1.
According to the silicon-based negative electrode material multiply coated by different graphene, the outer layer containing the liquid-phase-stripped graphene 3 is the sintered carbon layer 4 containing the liquid-phase-stripped graphene 3, the sintered carbon layer 4 is filled around the liquid-phase-stripped graphene 3, the mechanical performance of a system is further enhanced, and the volume effect of the coated nano silicon particles 1 can be greatly relieved, so that the silicon-based negative electrode material has good stability under the condition of keeping higher capacity.
According to the silicon-based negative electrode material multiply coated with different graphene, the particle size D50 of the nano silicon particle 1 is 50-200nm, other particle sizes can be adopted in other embodiments, however, D50 is preferably 50-200nm, if the particle size of the nano silicon particle 1 is too large, the volume effect is obvious, the nano silicon particle is easy to expand, the pulverization is serious, the circulation is poor, and if the particle size of the nano silicon particle 1 is too small, the process is difficult, and the cost is high.
According to the silicon-based negative electrode material multiply coated with different graphene, the nano silicon particles 1 can be further coated with the silicon dioxide layer, the silicon dioxide layer can be formed by hydrolyzing and coating the nano silicon particles with ethyl orthosilicate, the ethyl orthosilicate hydrolysis reaction uniformly coats the silicon dioxide layer on the surfaces of the nano silicon particles 1, so that the agglomeration effect of the nano silicon particles 1 is reduced, the silicon dioxide layer also has strong mechanical property and plays a role in protecting the nano silicon particles 1, and meanwhile, the silicon dioxide layer can also generate an intercalation and deintercalation reaction and is matched with the inner layer 2 of reduced graphene oxide, and the cycle stability of the structure of the silicon-based lithium battery negative electrode material is improved.
According to the silicon-based negative electrode material which is multi-coated by different graphene, the inner layer 2 of the reduced graphene oxide is prepared by reducing the graphene oxide, the plane of the graphene oxide contains-OH and C-OC, and the edge of the lamella contains C ═ O and COOH, so that the silicon-based negative electrode material has good stability in water, good wettability and surface activity, and is beneficial to intercalation stripping of the nano silicon particles 1 with silicon dioxide layers.
According to the silicon-based negative electrode material multiply coated with different graphene, the particle size D50 of the reduced graphene oxide can be 1um, 2um, 3um, 4um or 5um and the like, in some specific embodiments, the particle size D50 of the reduced graphene oxide is smaller than 2um, so that the reduced graphene oxide has a better buckling performance, in other specific embodiments, the particle size D50 of the reduced graphene oxide is larger than 1um, so that the process preparation of the reduced graphene oxide is facilitated.
According to the silicon-based negative electrode material multiply coated with different graphene in the specific embodiment of the invention, the particle size D50 of the liquid-phase exfoliated graphene 3 can be 1um, 2um, 3um, 4um, 5um, 6um, 7um, 8um, 9um, 10um and the like, in some specific embodiments, the particle size D50 of the liquid-phase exfoliated graphene 3 is less than 5um, so that the silicon-based negative electrode material has a better buckling performance, and in other specific embodiments, the particle size D50 of the liquid-phase exfoliated graphene 3 is greater than 3um, so that the silicon-based negative electrode material is beneficial to process preparation.
In the silicon-based negative electrode material multiply coated with different graphene according to the specific embodiment of the invention, the nano silicon particles: reducing graphene oxide: liquid-phase stripping of graphene: the weight ratio of the sintered carbon is 28-62: 2.5-10: 2.5-10: 28-62, and in further embodiments, the nano-silicon particles have a weight ratio of: reducing graphene oxide: liquid-phase stripping of graphene: the weight ratio of the sintered carbon is 42-46: 2.5-10: 2.5-10: 42-46.
In the silicon-based negative electrode material multiply coated with different graphene according to the specific embodiment of the present invention, the particle size D50 refers to a corresponding particle size when the cumulative particle size distribution percentage reaches 50%, the particles larger than the particle size account for 50%, the particles smaller than the particle size also account for 50%, and D50 is also called a median or median particle size.
According to the silicon-based negative electrode material multiply coated with different graphene, the number of nano silicon particles 1 coated with the inner layer 3 of the reduced graphene oxide can be 1, 2 or more than 2, and the number of particles coated with the inner layer 3 of the reduced graphene oxide by the outer layer containing the liquid phase exfoliated graphene 3 can be 1, 2 or more than 2.
According to the silicon-based negative electrode material multiply coated with different graphenes in the specific embodiment of the invention, the sintered carbon layer 4 is prepared by sintering carbon resin, specifically, phenolic resin, epoxy resin, glucose, chitosan, polyvinyl alcohol (PVA), and the like.
The preparation method adopting any silicon-based negative electrode material is characterized by comprising the following steps of 1) adding nano silicon particles into a graphene oxide solution for uniform dispersion, reducing and drying the graphene oxide; 2) uniformly mixing and dispersing the particles dried in the step 1), the liquid-phase stripping graphene solution and the carbon resin solution, drying and sintering.
The preparation method of the silicon-based anode material provided by the embodiment of the invention is as described above.
According to the preparation method of the silicon-based negative electrode material, in the step 1), before graphene oxide is added, the nano silicon particles 1 are modified by adopting a silane coupling agent, the nano silicon particles 1 modified by the silane coupling agent are positively charged, the graphene oxide is negatively charged, the graphene oxide can be tightly, uniformly and completely coated on the surfaces of the nano silicon particles 1 under the action of charges, and the nano silicon particles 1 obtained by the method can be almost completely coated by the graphene oxide. As a specific example, the silane coupling agent may be KH550, KH570, or the like.
The graphene oxide solution in step 1), the liquid-phase exfoliated graphene solution in step 2), and the carbon resin solution in the method for preparing a silicon-based anode material according to the embodiment of the present invention are not limited as long as the components thereof are favorably dispersed, and for example, the graphene oxide solution is an aqueous solution of graphene oxide, the liquid-phase exfoliated graphene solution is an ethanol solution of liquid-phase exfoliated graphene, and the carbon resin solution is an ethanol solution of carbon resin.
In the method for preparing a silicon-based negative electrode material according to the embodiment of the present invention, in step 2), a reducing agent for reducing graphene oxide may be a reducing agent commonly used for reducing graphene oxide, such as hydrazine hydrate, sodium hydrosulfite, vitamin C, and the like.
According to the preparation method of the silicon-based anode material, the sintering in the step 3) can adopt the sintering technology in the prior art, and specifically, for example, under the protection of inert atmosphere, the temperature rise rate is 5-20 ℃/min, the temperature is raised to 800-1200 ℃, and the temperature is kept for 1-10h and then the silicon-based anode material is cooled.
According to the lithium ion battery provided by the embodiment of the invention, the negative electrode slurry of the lithium ion battery comprises the silicon-based negative electrode material structure.
The following is a further description by way of specific examples.
Description of raw materials:
nano silicon particles (D50 about 150nm) Jiangsu Yongsheng New Material Co., Ltd
Phenolic resin Ji-Nanhui chemical technology Limited
Graphene oxide Hezhou sixth element science and technology Limited
The liquid phase stripping graphene is self-made, natural crystalline flake graphite, expanded graphite and the like are adopted, and are subjected to high-speed shearing and dispersion with a solvent and a dispersing agent, and then crushing, shearing and stripping are carried out in the modes of ball milling, grinding, homogenizing and the like to prepare the liquid phase stripping graphene.
Description of the test:
d50 particle size: dispersant OP-20 (a condensate of an alkylphenol and ethylene oxide) was added in an amount of 0.1 wt% of the total solution concentration in the test system, and sufficiently stirred and subjected to ultrasonic treatment for 2 minutes using an SK-1200H ultrasonic cleaner (frequency: 53 KHz; power: 50W) of Shanghai Ke ultrasonic instruments Ltd. The test was carried out using a laser particle size analyzer model S3500 from Microtrac.
And (3) performing electric deduction test: according to the formula, a silicon-based negative electrode material, namely sodium carboxymethylcellulose (CMC), styrene-butadiene rubber emulsion (SBR) and superconducting carbon black (SP-Li) is 93.15:2.35:3.5:1, slurry is mixed, the slurry is subjected to blade coating to prepare a pole piece (copper foil substrate), after a vacuum oven is dried, the pole piece is cut, electricity is prepared in a glove box and is connected with a detection system of a new-Wei high-performance battery, the test is carried out, the test comprises the specific capacity of first discharge, the specific capacity of first charge, the first coulombic efficiency and the capacity retention rate after 100 cycles, data are stored, and the figure is drawn by Origin software.
Example 1
1) Taking 7g of nano silicon and 20ml of deionized water, and carrying out ultrasonic treatment for 5 min; under the condition of stirring, 80g of graphene oxide aqueous solution (solid content: 1%) is added into the nano silicon particle solution, after 2h, 1g of sodium hydrosulfite is added into the solution, and after stirring for 1h, vacuum drying and crushing are carried out, so as to obtain the powder of the reduced graphene oxide coated nano silicon particles.
2) Taking about 11.67g of phenolic resin particles (the carbon formation rate of the phenolic resin is about 60% because of different carbon sources during sintering), adding the resin into a proper amount of ethanol under the condition of stirring, heating to be completely dissolved, then adding 20g (solid content is 4%) of Graphene (GN) ethanol slurry obtained by a liquid phase stripping method and the obtained reduced graphene oxide coated nano silicon particle powder into a phenolic resin solution, fully stirring for 3h, drying in vacuum, crushing, heating to 1000 ℃ at the heating rate of 5 ℃/min under the protection of inert atmosphere, preserving heat for 2h, and cooling to obtain sintered powder.
Example 2
The mass of silicon was changed to 3.5g compared with example 1, and the others were unchanged.
Example 3
The mass of silicon was changed to 14g compared with example 1, and the others were unchanged.
Example 4
The mass of the aqueous graphene oxide solution was 40g as compared with example 1, and the rest was unchanged.
Example 5
The mass of the aqueous graphene oxide solution was 160g as compared with example 1, and the rest was unchanged.
Example 6
The mass of the liquid phase exfoliation method graphene solution was 10g compared to example 1, and the rest was unchanged.
In the case of the example 7, the following examples are given,
the mass of the liquid phase exfoliation method graphene solution was 40g compared to example 1, and the rest was unchanged.
Example 8
The mass of the phenolic resin particles was 5.835g, compared with example 1, and the rest was unchanged.
Example 9
The mass of the phenolic resin particles was changed to 23.34g compared with example 1, and the rest was unchanged.
Example 10
The graphene oxide size D50 used was about 2um compared to example 1, and the others were unchanged.
Example 11
The graphene oxide size D50 used was about 3um compared to example 1, and the others were unchanged.
Example 12
Compared with example 1, the graphene size D50 is about 5um by liquid phase exfoliation, and the others are unchanged.
Example 13
Compared with example 1, the graphene size D50 is about 7um by liquid phase exfoliation, and the others are unchanged.
Comparative example 1
Pure nano silicon particles.
Comparative example 2
1) Taking 7g of nano silicon and 20ml of deionized water, and carrying out ultrasonic treatment for 5 min; under the condition of stirring, 80g of graphene oxide aqueous solution (solid content: 1%) is added into the nano silicon particle solution, after 2h, 1g of sodium hydrosulfite is added into the solution, and after stirring for 1h, vacuum drying and crushing are carried out, so as to obtain the powder of the reduced graphene oxide coated nano silicon particles.
2) Taking about 11.67g of phenolic resin particles (the carbon formation rate of the phenolic resin is about 60% because of different carbon sources during sintering), adding the resin into a proper amount of ethanol under the stirring condition, heating to be completely dissolved, adding the obtained reduced graphene oxide coated nano silicon particle powder into a phenolic resin solution, fully stirring for 3 hours, drying in vacuum, crushing, heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of an inert atmosphere, preserving heat for 2 hours, and cooling to obtain sintered powder.
Comparative example 3
Taking about 11.67g of phenolic resin particles (the carbon formation rate of the phenolic resin is about 60% because of different carbon sources during sintering), adding the resin into a proper amount of ethanol under the stirring condition, heating to be completely dissolved, adding 20g (solid content is 4%) of Graphene (GN) ethanol slurry prepared by a liquid phase stripping method and 7g of nano silicon particle powder into a phenolic resin solution, fully stirring for 3h, drying in vacuum, crushing, heating at a heating rate of 5 ℃/min under the protection of an inert atmosphere, heating to 1000 ℃, preserving heat for 2h, and cooling to obtain sintered powder.
Comparative example 4
1) Taking 7g of nano silicon and 20ml of deionized water, and carrying out ultrasonic treatment for 5 min; under the condition of stirring, 80g of graphene oxide aqueous solution (solid content: 1%) is added into the nano silicon particle solution, after 2h, 1g of sodium hydrosulfite is added into the solution, and after stirring for 1h, vacuum drying and crushing are carried out, so as to obtain the powder of the reduced graphene oxide coated nano silicon particles.
2) Taking a proper amount of ethanol, adding 20g (solid content is 4%) of Graphene (GN) ethanol slurry obtained by a liquid phase stripping method and the obtained reduced graphene oxide coated nano silicon particle powder into the ethanol, fully stirring for 3h, drying in vacuum, crushing, heating to 1000 ℃ at a heating rate of 5 ℃/min under the protection of inert atmosphere, preserving heat for 2h, and cooling to obtain sintered powder.
The snap-in test method of the silicon-based lithium battery negative electrode materials of examples 1-13 and comparative examples 1-4 is used for the test of the buckling performance, wherein figure 2 is a test chart of the buckling performance of example 1, the test chart of the buckling performance of other examples and comparative examples is omitted, and the specific data of the buckling performance are listed in the attached table 1.
TABLE 1 attached test data for power on test of examples 1-10 and comparative examples 1-4
As can be seen from example 1 and comparative examples 1 to 4, the silicon-based negative electrode material with multiple coatings is higher than the silicon-based negative electrode material coated with pure reduced graphene oxide or pure liquid-phase exfoliated graphene in terms of initial coulombic efficiency and cycle stability, and is much higher than pure nano-silicon.
Examples 1 to 9 show that, when the addition amounts of the nano-silicon particles, the reduced graphene oxide, the liquid-phase exfoliated graphene and the carbon source are different, the differences of the specific capacity, the first coulombic efficiency and the cycling stability are caused, the specific mixture ratio can be reasonably arranged according to the requirements under different conditions, and the nano-silicon particles: reducing graphene oxide: liquid-phase stripping of graphene: the weight ratio of the sintered carbon is 42-46: 2.5-10: 2.5-10: 42-46, which have better specific capacity and cycling stability effects, such as examples 1, 4-7; examples 2, 3, 8, 9 either had relatively low specific capacity or poor cycling stability.
Examples 1, 10-13 show that the dimensions of the reduced graphene oxide (graphene oxide) are selected such that when the reduced graphene oxide (graphene oxide) is less than or equal to 2um, the fastening performance is better than that of 3um, and the fastening performance is not much different from that of 1 um. The size of the liquid phase stripping graphene is selected, when the size of the liquid phase stripping graphene is less than or equal to 5um, the buckling electrical property of the liquid phase stripping graphene is superior to that of the liquid phase stripping graphene when the size of the liquid phase stripping graphene is 7um, and the buckling electrical property of the liquid phase stripping graphene is not greatly different from that of the liquid phase stripping graphene when the size of the liquid phase stripping graphene is 3 um.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (10)
1. The silicon-based negative electrode material is characterized in that the silicon-based negative electrode material structure comprises nano silicon particles and a graphene multi-coating layer coating the nano silicon particles, wherein the graphene multi-coating layer is composed of an inner layer of reduced graphene oxide and an outer layer of liquid-phase-stripping graphene.
2. The silicon-based anode material according to claim 1, wherein the outer layer comprising liquid-phase-exfoliated graphene is a sintered carbon layer comprising liquid-phase-exfoliated graphene.
3. The silicon-based anode material of claim 1, wherein the reduced graphene oxide has a particle size D50 of less than 2 um.
4. The silicon-based anode material of claim 1, wherein the reduced graphene oxide has a particle size D50 of greater than 1 um.
5. The silicon-based anode material of claim 1, wherein the liquid-phase exfoliated graphene has a particle size D50 of less than 5 um.
6. The silicon-based anode material of claim 1, wherein the liquid-phase exfoliated graphene has a particle size D50 of greater than 3 um.
7. The silicon-based anode material as claimed in claim 1, wherein the nano silicon particles have a particle size D50 of 50-200 nm.
8. The silicon-based anode material according to claim 1, wherein the silicon-based anode material is composed of nano-silicon particles, reduced graphene oxide sequentially coating the nano-silicon particles, and a sintered carbon layer containing liquid-phase exfoliated graphene.
9. The silicon-based anode material of claim 8, wherein the nano-silicon particles: reducing graphene oxide: liquid-phase stripping of graphene: the weight ratio of the sintered carbon is 28-62: 2.5-10: 2.5-10: 28-62.
10. A method for preparing a silicon-based anode material according to any one of claims 1 to 9, comprising the steps of 1) adding nano silicon particles into a graphene oxide solution for uniform dispersion, reducing and drying the graphene oxide; 2) uniformly mixing and dispersing the particles dried in the step 1), the liquid-phase stripping graphene solution and the carbon resin solution, drying and sintering.
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| CN111613791A (en) * | 2020-06-24 | 2020-09-01 | 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 |
| CN113921775A (en) * | 2021-08-02 | 2022-01-11 | 江苏杉元科技有限公司 | By using SiO2Silicon-based negative electrode material structure multiply coated with rGO |
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