CN116230946A - Composite lithium electrode material and preparation method and application thereof - Google Patents

Composite lithium electrode material and preparation method and application thereof Download PDF

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CN116230946A
CN116230946A CN202310505322.0A CN202310505322A CN116230946A CN 116230946 A CN116230946 A CN 116230946A CN 202310505322 A CN202310505322 A CN 202310505322A CN 116230946 A CN116230946 A CN 116230946A
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lithium
electrode material
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perfluoropolyether
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CN116230946B (en
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陈立宝
黄绍祯
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Central South University
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    • H01G11/04—Hybrid capacitors
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    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/50—Electrodes characterised by their material specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
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Abstract

The invention discloses a composite lithium electrode material, a preparation method and application thereof. The composite lithium electrode material comprises a lithium-containing matrix and a surface-coated hybrid interface protection layer, wherein the hybrid interface protection layer comprises perfluoropolyether, lithium fluoride and lithium carbon compounds. The lithium ion conductive polymer has high conductivity, high interface ion diffusivity and super-strong lithium affinity, can stabilize a matrix interface, and reduces the consumption of electrolyte. When the lithium ion battery is applied to a lithium ion battery energy storage device, the electrochemical performance can be effectively improved. The preparation method is simple, low in cost and suitable for industrial mass production.

Description

Composite lithium electrode material and preparation method and application thereof
Technical Field
The invention relates to an electrode material, in particular to a composite lithium electrode material, a preparation method and application thereof, and belongs to the technical field of electrode materials.
Background
In recent years, energy density requirements of energy storage and power batteries are higher and higher, and specific capacity of a traditional lithium ion battery cathode material is exerted to a bottleneck, so that the lithium ion battery is difficult to meet the requirements. The extremely high theoretical specific capacity (3860 mAh/g) of the lithium metal negative electrode makes it possible to further develop a high energy density battery. At present, the lithium metal negative electrode has extremely short service life in application because of dendrite growth and a large number of side reactions caused by high activity in the use process of the battery. The rapid growth of lithium dendrite caused by high current and the severe volume change under high capacity can cause short circuit to cause battery safety problem, which also greatly hinders the market application of the battery.
Yue Yu et al ("In Situ Designing a Gradient Li) + Capture and Quasi-Spontaneous Diffusion Anode Protection Layer toward Long-Life Li-O 2 The fluorine-doped carbon layer is obtained by directly heating polytetrafluoroethylene and a lithium metal matrix to 300 ℃ for reaction by using the materials 'Adv, mater, 2020 (32), 2004157', but the reaction is extremely easy to cause thermal runaway, high in safety risk and high in energy consumption, and the generated interface is a particle stack, easy to fall off, and the continuity and uniformity of the modified carbon layer are in good care. The electrode material performance is improved to a certain extent by directly dripping perfluoropolyether on the surface of lithium metal by Qian Yang et al (C-F-rich oil drop as a non-expendable fluid interface modifier with low surface Energy to stabilize a Li metal anode', energy environment, sci., 2021 (14), 3621), but the electrode material has the problems of uncontrollable thickness, poor interface electronic conductivity, strong liquid fluidity, poor preparation process consistency and the like. Therefore, the development of a lithium electrode material with high ion conductivity, good stability and safety has important significance.
Disclosure of Invention
In view of the shortcomings of the prior art, a first object of the present invention is to provide a composite lithium electrode material. The lithium electrode material has high conductivity and interfacial ion diffusivity, and super-strong lithium affinity, can induce high-capacity and high-current uniform deposition of lithium ions, and simultaneously prevent the electrolyte from reacting with a matrix, so that the interface of the matrix can be stabilized, and the consumption of electrolyte can be reduced.
The second object of the present invention is to provide a method for preparing a composite lithium electrode material. The method is simple, low in cost and suitable for industrial mass production.
A third object of the present invention is to provide the use of a composite lithium electrode material. When the lithium ion battery is used as a negative electrode of a lithium ion battery energy storage device, the electrochemical performance can be effectively improved.
In order to achieve the technical aim, the invention provides a composite lithium electrode material, which comprises a lithium-containing matrix and a surface-coated hybrid interface protection layer, wherein the hybrid interface protection layer comprises perfluoropolyether, lithium fluoride and lithium carbon compound.
The lithium fluoride and the lithium carbon compound in the hybridized interface protection layer are uniformly dispersed in the perfluoropolyether, wherein the lithium fluoride, the lithium carbon compound and the perfluoropolyether form a colloidal semi-solidified phase through the actions of hydrogen bond or adsorption and the like, so that the whole interface layer is a continuous and uniform organic-inorganic hybridized interface protection layer.
As a preferred embodiment, the lithium-containing matrix comprises elemental lithium and/or a lithium-based composite material. The lithium-based composite material can be a lithium alloy (such as LiSn alloy, liIn alloy and LiAl alloy), a lithium-boron composite material or a composite material formed by at least one of a lithium simple substance, a lithium alloy and a lithium-boron composite material and a framework material. The framework material comprises copper, nickel, carbon, stainless steel, conductive polymers and the like. The copper material may be copper foam, copper mesh, or the like. The nickel material may be foam nickel, nickel mesh, or the like. The carbon material may be carbon cloth, carbon paper, or the like. The conductive polymer may be porous polymer fibers such as an aramid mesh, a polyester mesh, an acrylic mesh, a nylon mesh, a polyimide mesh, a polypropylene mesh, a polytetrafluoroethylene mesh, a polyvinylidene fluoride mesh, and the like.
As a preferable scheme, the content of the perfluoropolyether in the interface protective layer is 0.1-20wt%, and more preferably 5-10wt%. Controlling the content of the perfluoropolyether in a proper range can improve the performance of the electrode material, if the content is too high, the ion conductivity of the interface layer is relatively reduced, and if the content is too low, the solvation degree at the interface is high, and the high-rate charge and discharge performance is affected to a certain extent.
As a preferable scheme, the molecular weight of the perfluoropolyether is 100-3000. The selection of the perfluoropolyether of the appropriate molecular weight enables a better performing hybrid interfacial layer. When the molecular weight of the perfluoropolyether is too large, the reaction limit of PTFE and lithium is reduced, the PFPE content in the interface layer is increased, the inorganic component proportion is reduced, and the electrochemical performance of the composite material is affected to a certain extent; when the molecular weight of the perfluoropolyether is too small, the interfacial viscosity formed is low, and the desired colloidal state cannot be formed.
As a preferable scheme, the content of the lithium fluoride in the interface protection layer is 0.1-50wt%, and more preferable is 15-35wt%. Controlling the lithium fluoride content in a suitable range is beneficial to improving the performance of the interface layer, and too low or too low content can lead to relatively reduced ionic conductivity of the interface layer.
As a preferable embodiment, the thickness of the lithium-containing matrix is 5 μm to 1000 μm, more preferably 20 μm to 200 μm, and the thickness of the interface protection layer is 100nm to 5 μm, more preferably 500nm to 5 μm.
The invention also provides a preparation method of the composite lithium electrode material, which comprises the steps of coating slurry containing polytetrafluoroethylene and perfluoropolyether on the surface of a lithium-containing substrate, and obtaining the composite lithium electrode material through compression molding.
During the forming process, polytetrafluoroethylene (PTFE) and a lithium-containing matrix are decomposed and react with lithium in the friction process, and the reaction process is as follows:
Figure SMS_1
the perfluoropolyether has two important roles in the process, on one hand, the reaction degree of PTFE and Li is regulated and controlled, the severe reaction is limited, and thermal runaway is prevented, because the perfluoropolyether has excellent heat insulation performance, heat can be blocked when PTFE reacts with pure lithium, and the interface temperature is prevented from being rapidly increased; on the other hand, inorganic products (lithium fluoride, lithium carbon compounds) generated by the surface reaction are uniformly dispersed, so that the inorganic products are continuous, and a colloidal semi-solidified phase is formed, so that a uniform and stable organic-inorganic hybridization interface layer is formed.
As a preferable scheme, the mass ratio of the polytetrafluoroethylene to the perfluoropolyether is 6-50:50-94. The mass ratio of the polytetrafluoroethylene to the perfluoropolyether is 6-30:70-94. The mass ratio of polytetrafluoroethylene to perfluoropolyether is controlled in a proper range, so that an electrode material with excellent performance can be obtained, and the content of the perfluoropolyether in an interface layer formed by excessive polytetrafluoroethylene is low, so that the desolvation of lithium is not facilitated; and the lithium fluoride content in the interface layer is lower due to the too small amount of polytetrafluoroethylene, so that the ionic conductivity of the interface layer is affected.
As a preferable scheme, the polytetrafluoroethylene is used in an amount of 0.1-25 wt% of the lithium-containing matrix, and more preferably 5-15 wt%. The amount of polytetrafluoroethylene directly affects the content of the interface layer inorganic matters (LiC compound and LiF), so that the electrode material with excellent performance can be obtained by controlling the amount of polytetrafluoroethylene in a reasonable range, the content of the interface layer inorganic matters can be reduced by too small amount, the ionic conductivity and the electrical conductivity of the material are relatively reduced, and the thermal runaway in the reaction process can be caused by too large amount, so that the reaction regulation and control are not facilitated.
In a preferred embodiment, the particle size of the polytetrafluoroethylene is 1nm to 1000. Mu.m, more preferably 100nm to 500. Mu.m.
As a preferred embodiment, the slurry containing polytetrafluoroethylene and perfluoropolyether is prepared by the following steps: and mixing polytetrafluoroethylene and perfluoropolyether at the temperature of 10-90 ℃.
As a preferable embodiment, the press forming includes at least one of rolling, stamping, and extruding.
As a preferable scheme, the press molding is rolling, the temperature is controlled to be room temperature in the rolling process, and the thickness deformation of the lithium-containing matrix is 0.1-80%. The thickness deformation amount of the lithium-containing matrix is more preferably 15 to 30%.
The invention also provides application of the composite lithium electrode material, which is used as a negative electrode of the lithium battery energy storage device. Lithium-ion energy storage devices include lithium ion batteries, lithium sulfur batteries, lithium-air batteries, capacitors, and the like.
As a preferred embodiment, the lithium battery is used as a negative electrode. When the composite electrode material is applied to a lithium battery, the high-current density and high-multiplying power application of the lithium negative electrode can be realized, and the problem of dendrite growth of the lithium negative electrode under the condition can be effectively solved.
Compared with the prior art, the invention has the following beneficial effects:
(1) The lithium electrode material has high lithium ion conductivity and super-strong lithium affinity through the organic-inorganic hybrid interface protective layer coated on the surface of the matrix, and can induce the uniform deposition of lithium ions with large capacity and high current, so that the surface of the electrode is kept dynamically stable; meanwhile, the electrolyte is prevented from reacting with the matrix, the electrode plate interface is stabilized, and the consumption of electrolyte is reduced;
(2) The hybridized interface protection layer has ultralow interface potential, so that the interface potential of the composite lithium electrode material can be remarkably reduced by 30 times compared with an untreated lithium-containing matrix;
(3) When the composite lithium electrode material is applied to a lithium battery energy storage device, the electrochemical performance can be improved, and particularly when the composite lithium electrode material is used as a lithium battery negative electrode, the composite lithium electrode material has good cycling stability, can realize the high-current density high-multiplying power application of the lithium negative electrode, and effectively solves the dendrite growth problem of the lithium negative electrode under the condition;
(4) The preparation method is simple, low in cost and suitable for industrial scale production, and the composite electrode material can be directly thinned in the in-situ reaction process in a load application mode, so that the preparation of the ultrathin electrode material is realized.
Drawings
FIG. 1 is an optical view showing the surface of the electrode material prepared in example 1 and comparative example 1 according to the present invention, wherein (a) is the composite electrode material of example 1 and (b) is the electrode material of comparative example 1.
Fig. 2 is a cross-sectional SEM and an energy spectrum EDS of the composite electrode material prepared in example 1 of the present invention, wherein (a) is an SEM image, (b) is a cross-sectional elemental surface scan of element C, (C) is a cross-sectional elemental surface scan of element F, and (d) is a cross-sectional elemental surface scan of element O.
FIG. 3 is XPS of a polytetrafluoroethylene and perfluoropolyether containing slurry (perfluoropolyether grease) directly coating a lithium pole piece, where (a) is C1 s; (b) is F1 s; (c) is O1 s; and (d) is Li 1s.
FIG. 4 shows XPS of a composite electrode material prepared in example 1 according to the present invention, wherein (a) is C1 s; (b) is F1 s; (c) O1 s; and (d) is Li 1s.
FIG. 5 is a photograph under a frozen TEM electron microscope and a diffraction pattern of the composite lithium electrode material prepared in example 1, wherein (a) is an electron imaging pattern in a surface substance TEM obtained by sample preparation; (b) an electron diffraction pattern of the surface material.
FIG. 6 is a chart of a secondary mass spectrometry test of the composite lithium electrode material prepared in example 1.
Fig. 7 is a view showing wetting angle measurement in an electrolyte of the electrode materials prepared in example 1 and comparative example 1 according to the present invention, wherein (a) is the composite electrode material of example 1 and (b) is the electrode material of comparative example 1.
Fig. 8 is a graph showing interfacial electrostatic potential test in KPFM mode under an atomic force microscope for the electrode materials prepared in example 1 and comparative example 1 according to the present invention, wherein (a) is the composite electrode material of example 1 and (b) is the electrode material of comparative example 1.
FIG. 9 shows that the electrode materials prepared in example 1 and comparative example 1 of the present invention were prepared at a density of 1 mA/cm 2 1mAh/cm 2 Symmetrical cycle performance test chart under the condition.
FIG. 10 shows that the electrode materials prepared in example 1 and comparative example 1 of the present invention were prepared at 18 mA/cm 2 3mAh/cm 2 Symmetrical cycle performance test chart under the condition.
FIG. 11 shows the assembly of the electrode materials prepared in example 1 and comparative example 1 of the present invention with lithium iron phosphate, respectivelyThe cycle efficiency of the full cell of (2) at 1C rate, wherein the positive electrode active material is loaded with 16 mgcm -2 。
FIG. 12 is a graph showing the 0.1C, 0.5C, 1C, 2C, 5C, and 0.1C rate test of a full cell assembled with lithium iron phosphate, respectively, of the electrode materials prepared in example 1 and comparative example 1 according to the present invention, wherein the positive electrode active material was supported by 2mgcm -2 。
FIG. 13 shows that the electrode material prepared in example 2 of the present invention was prepared at 18 mA/cm 2 3mAh/cm 2 Symmetrical cycle performance test chart under the condition.
FIG. 14 shows that the electrode material obtained in example 3 of the present invention was prepared at 18 mA/cm 2 3mAh/cm 2 Symmetrical cycle performance test chart under the condition.
Detailed Description
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit or scope of the invention, which is therefore not limited to the specific embodiments disclosed below.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
The rolling equipment used in the invention is MRX-DG150L, which is purchased from Ming Ruixiang Automation Equipment Co., shenzhen City.
The commercial lithium belt adopted by the invention is purchased in Tianjin and can be used in lithium industry, the thickness is 200 micrometers, the width is 90cm, and the length is 1m.
The perfluoropolyether in the invention is the milin reagent P910107 perfluoropolyether Perfluoropolyether oil (cas: 60164-51-4), and has the specification: mw is 1500.
Example 1
Polytetrafluoroethylene (CAS: 9002-84-0, P816159, microphone) and perfluoropolyether were stirred at a mass ratio of 20:80 for 1 hour at 60 ℃ to obtain a thickened perfluoropolyether ester. Then coating the thickened and modulated perfluoro polyether grease (polytetrafluoroethylene accounts for 25 wt%) on the surface of a lithium metal sheet (the coating thickness is 0.5 micrometers), wherein the polytetrafluoroethylene accounts for 5% of the mass of the metal lithium sheet (the thickness is 150 micrometers); the method of rolling at room temperature is adopted, a rolling mill with the model MRX-DG150L is used for longitudinal rolling, the rolling reduction (thickness deformation) is 16.67%, a composite sheet is obtained, and then punching is carried out to obtain a composite electrode sheet with the diameter of 16 mm (the thickness is 150 micrometers), and the composite electrode sheet is marked as Li@CFO.
The optical photograph of the surface of the electrode sheet is shown in fig. 1 (a), and the surface of the electrode sheet is coated with a hybridization layer.
The cross-sectional energy spectrum of the hybrid layer of the composite electrode material was obtained under a scanning electron microscope (MIRA 4 LMH, TESCAN, czech equipment), as shown in fig. 2, in which it can be seen that three elements C, F, O are present in the hybrid layer.
An XPS map of the interface of the composite electrode material prepared in this example was obtained using a Thermo Fisher apparatus, as shown in FIG. 4, wherein inorganic carbon (including Li-C) was present in (a), (b) LiF was included, and (d) LiF was included on the surface. While FIG. 3 shows XPS results for an unrerolled surface coated with a perfluoropolyether lipolithium metal sheet interface with no inorganic carbon in (a), (LiF in (b), and Li in the surface in (d).
The topography and diffraction patterns of the surface hybridization layer of the composite electrode material were obtained with a Titan G2 60-300, FEI apparatus under a frozen TEM, as shown in FIG. 5, which demonstrates LiC 6 Is present.
The apparatus of Gmhb 5, munster, germany obtained a secondary time-of-flight mass spectrum of the composite electrode material, as shown in FIG. 6, in which C-O-C demonstrates the presence of ether linkages in the perfluoropolyether.
The composite pole piece obtained in the embodiment is dissolved with 1M LiTFSI lithium salt, the solvent volume ratio is DME: DOL=1:1, and the composite pole piece contains 2wt% LiNO 3 The wetting angle test was performed in the electrolyte of the additive, and the test results are shown in fig. 7 (a), and it can be seen from the figure that the wetting angle was reduced by 5 times compared with the original lithium sheet (b).
The surface electrostatic potential of the composite electrode material prepared by the invention is reduced by 30 times compared with the original lithium sheet (b) as shown in fig. 8 (a) by adopting a KPFM mode under an atomic force microscope to test the surface electrostatic potential of the composite electrode material.
In a glove box, assembling the composite pole piece and the lithium piece into a button cell, adopting Celgard2400 as a diaphragm, dissolving 1M LiTFSI lithium salt serving as electrolyte in a solvent with volume ratio of DME to DOL=1 to 1, and containing 2wt% LiNO 3 The additive is used for carrying out constant-current charge and discharge test on the polar plate at 1 mA/cm 2 1mAh/cm 2 The symmetrical battery cycle test is carried out under the test condition, the test result is shown in figure 9, and the figure shows that the test result can realize more than 2400 circles of stable cycle; the polarization voltage is still not more than 0.2V; at 18 mA/cm 2 3mAh/cm 2 The test results are shown in fig. 10, and it can be seen from the graph that under the conditions of large current and large capacity, the battery can realize stable circulation for more than 1400 circles, and the polarization voltage is still not more than 0.5V.
The composite pole piece with the diameter of 16 mm is used as a cathode and LiFePO4 anode to assemble a full battery, celgard2400 is used as a diaphragm, and the electrolyte is 1.0M LiPF 6 EC: EMC, fec=1:1:1 (volume ratio). Full cell cycle testing was performed under 1C test conditions, and the results are shown in fig. 11, and fig. 11 shows that the 450 cycles of cycle capacity retention reaches 99.9%.
The composite pole piece with the diameter of 16 mm is used as a negative electrode and LiFePO 4 The positive electrode assembled full cell, using Celgard2400 as separator, electrolyte 1.0M LiPF6 EC:EMC:FEC =1:1:1 (volume ratio), was subjected to full cell rate testing under different test conditions of 0.1C, 0.5C, 1C, 2C, 5C, 0.1C, respectively, and the test results are shown in fig. 12, wherein the cell still maintains a specific discharge capacity of approximately 135mAh/g by the time of 5C testing.
Example 2
A composite lithium electrode material was prepared by the method of example 1, except that: the mass ratio of polytetrafluoroethylene to perfluoropolyether is 15:85.
The properties of the resulting composite lithium electrode material were similar to those of example 1. The pole piece prepared under the conditions of the example was treated with electrolyte (1M LiTFSI/DME: DOL=1:1 #Volume ratio), contains 2% LiNO 3 Additive) was tested electrochemically, as shown in FIG. 13, at 18 mA/cm 2 3mAh/cm 2 The symmetrical cell can be cycled for a long period of 390 hours and still maintain a low polarization voltage.
Example 3
A composite lithium electrode material was prepared by the method of example 1, except that: the mass ratio of polytetrafluoroethylene to perfluoropolyether is 5:95.
The pole piece prepared under the condition is subjected to electrolytic solution (1M LiTFSI/DME: DOL=1:1 (volume ratio) and contains 2% LiNO 3 Additive) was tested electrochemically, as shown in FIG. 14, at 18 mA/cm 2 3mAh/cm 2 Under the conditions, the symmetrical cell was able to maintain a small polarization voltage after a long cycle of 120 hours, with a reduced performance compared to example 1, but a doubling of performance compared to comparative example 1 (pure lithium). This is mainly due to the relatively reduced thickening effect of the perfluoropolyether grease caused by the reduced content of Polytetrafluoroethylene (PTFE), the overall slurry being thinner, and the hybrid layer having a low content of inorganic components after rolling is completed, resulting in a relatively reduced performance.
Comparative example 1
The surface of the original commercial lithium strip is shown in fig. 1 (b), and as can be seen from the figure, the surface has metallic luster. Two commercial lithium bands (medium energy lithium industry) are used as positive and negative electrode assembled button type symmetrical battery, celgard2400 is used as a diaphragm, and 1M LiTFSIDME:DOL=1:1 (volume ratio) electrolyte contains 2% LiNO 3 Additives, at 1 mA/cm 2 1mAh/cm 2 The symmetrical battery cycle test is carried out under the test condition, and the test result is shown in fig. 9, and the test result shows that the test can only stably circulate for 400 circles and the polarization voltage is increased to 0.1V; at 18 mA/cm 2 3mAh/cm 2 The symmetrical cell cycle test was performed under test conditions, and the test results are shown in fig. 10, which shows that it can be stably cycled only for 100 turns and the polarization voltage is increased to 0.5V.
The commercial lithium belt is used as a negative electrode and LiFePO 4 Positive electrode assembled full cell, celgard2400 was used as separator, and electrolyte was 1.0M LiPF 6 EC:EMC:FEC=1:1:1 (volume ratio). Full battery cycle testing was performed under 1C test conditions and full battery rate testing was performed under 0.1C, 0.5C, 1C, 2C, 5C, 0.1C different test conditions, the results of which are shown in fig. 11 and 12. As can be seen from fig. 11, at 1C magnification, the capacity decays to 21.5% after 150 cycles; as can be seen from fig. 12, as the magnification increases, the specific discharge capacity is always lower than that of example 1.

Claims (10)

1. A composite lithium electrode material, characterized in that: the lithium-containing hybrid interface protective layer comprises a lithium-containing matrix and a surface-coated hybrid interface protective layer, wherein the hybrid interface protective layer comprises perfluoropolyether, lithium fluoride and lithium carbon compound;
the content of the perfluoropolyether in the interface protective layer is 0.1-20wt%;
the content of the lithium fluoride in the interface protection layer is 0.1-50wt%.
2. A composite lithium electrode material according to claim 1, characterized in that: the lithium-containing matrix comprises a simple lithium and/or a lithium-based composite.
3. A composite lithium electrode material according to claim 1 or 2, characterized in that: the molecular weight of the perfluoropolyether is 100-3000.
4. A composite lithium electrode material according to claim 1, characterized in that: the thickness of the lithium-containing matrix is 5 mu m-1.5 mm, and the thickness of the interface protection layer is 100-5000 nm.
5. The method for preparing the composite lithium electrode material according to claim 1-4, which is characterized in that: and coating the slurry containing polytetrafluoroethylene and perfluoropolyether on the surface of a lithium-containing substrate, and performing compression molding to obtain the composite lithium electrode.
6. The method for preparing a composite lithium electrode material according to claim 5, wherein:
the mass ratio of the polytetrafluoroethylene to the perfluoropolyether is 6-50:50-94;
the dosage of the polytetrafluoroethylene is 0.1-25wt% of the lithium-containing matrix.
7. The method for preparing a composite lithium electrode material according to claim 5, wherein: the press forming comprises at least one of rolling, stamping and extruding.
8. The method for preparing a composite lithium electrode material according to any one of claims 5 to 7, characterized in that: the pressing forming is rolling, the temperature is controlled to be at room temperature in the rolling process, and the thickness deformation of the lithium-containing matrix is 0.1-80%.
9. The application of the composite lithium electrode material as claimed in claim 1-4, which is characterized in that: the lithium ion battery is used as a negative electrode of a lithium ion battery energy storage device.
10. The use of a composite lithium electrode material according to claim 9, characterized in that: as the negative electrode of a lithium battery.
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