CN104103809B - Three-layer electrode structure for alloy anode of lithium ion battery - Google Patents

Abstract

The invention relates to a three-layer electrode structure for an alloy negative electrode of a lithium ion battery. The three-layer electrode structure includes a current collector layer, a lithium active material layer, and an inert material protective layer stacked in sequence; the inert material protective layer has The inert protection substance is a high molecular polymer fiber that does not undergo lithium intercalation and deintercalation reactions within the range of cyclic voltage and has elasticity and conductivity. Aiming at the inherent volume expansion effect of the alloy negative electrode, the present invention adopts a three-layer electrode structure from the perspective of process structure design, and the protective layer of inert material is located on the surface of the active material layer. The internal stress generated by the effect prevents the electrode material from being pulverized and broken, ensures the integrity of the electrode, and maintains the electrical contact between the active material and the current collector. At the same time, the protective layer of inert material isolates the direct contact between the active material layer and the electrolyte, reducing the corrosion of the active material by the electrolyte.

Description

A kind of three-layer electrode structure for lithium ion battery alloy negative electrode

technical field

The invention relates to a lithium ion secondary battery, in particular to a three-layer electrode structure for the lithium ion battery alloy negative electrode.

Background technique

The energy crisis is intensifying, and there is an urgent need for new energy sources with high power and high energy to replace fossil energy sources. Lithium-ion batteries have been attracting attention for their advantages such as high specific energy density, long cycle life, and no pollution. In the study of its negative electrode materials, a class that can form an alloy with Li and have a high specific capacity has aroused great interest, such as Sn, Sb, Si, Ge, etc. and their compounds (Li _4.4 Si, 4200mAh· g ^-1 ). However, this type of alloy negative electrode has a serious volume effect (>300%) in the process of electrochemically deintercalating lithium ions, and the mechanical stress generated will pulverize the active material of the alloy and rapidly lose electrical contact, resulting in capacity decay and electrode failure. The decreased electrochemical cycle stability severely limits the practical application of such anode materials.

At present, the main ideas to solve this problem are mainly focused on the modification and design of the microstructure of electrode materials, including reducing the particle size of active materials (such as nanometerization) and introducing composite materials. For example, CN101877399B discloses a preparation method of a three-dimensional porous tin-copper alloy negative electrode material for lithium-ion batteries. By using foamed copper as a current collector, a tin-plated layer is chemically deposited on it, and a three-dimensional porous tin-copper alloy negative electrode material is formed by vacuum heat treatment. , using the three-dimensional porous structure, the formation of tin-copper alloy and the excellent binding force between tin-copper alloy film and porous current collector can effectively prevent the active material from falling off from the current collector due to volume expansion. CN102324501B discloses a method for preparing a silicon-based negative electrode composite material for lithium-ion batteries. Under the catalysis of _CuOx , silicon reacts with halogenated hydrocarbons to catalyze the silicon material to form pores in situ, and the silicon material is catalyzed to form pores by impregnation, carbonization or chemical vapor deposition. The surface of porous silicon and the inner wall of pores are modified with carbon to obtain a porous Si/CuO _x /C composite material in which carbon in different forms is uniformly distributed on the surface of the silicon-based material and on the pore walls. Although the prepared alloy negative electrode has excellent cycle performance, high charge and discharge capacity, and small initial irreversible capacity, the operating conditions are harsh, the cost is high, it is not suitable for large-scale commercial production, and the safety factor is low.

However, the current research only focuses on the microstructure of the electrode material itself, and rarely involves the design of the lithium-ion battery alloy anode electrode structure.

Contents of the invention

The purpose of the present invention is to design the electrode structure of the lithium-ion battery alloy negative electrode, aiming at the internal stress of the electrode material due to the volume effect during the lithium-ion battery deintercalation process. To solve the problem of performance attenuation, a three-layer electrode structure is adopted, and a protective layer is introduced on the surface of the active electrode to alleviate the volume effect, maintain the integrity of the electrode during the cycle, and improve the electrochemical performance of the alloy negative electrode material.

Here, the present invention provides a three-layer electrode structure for a lithium ion battery alloy negative electrode, the three-layer electrode structure comprising a current collector layer, a deintercalation lithium active material layer, and an inert material protective layer stacked in sequence; the inert material The inert protective material in the protective layer is a high molecular polymer fiber that does not undergo lithium intercalation and deintercalation reactions within the range of cyclic voltage and has elasticity and conductivity.

Aiming at the inherent volume expansion effect of the alloy negative electrode, the present invention adopts a three-layer electrode structure from the perspective of process structure design, and the protective layer of inert material is located on the surface of the active material layer. The internal stress generated by the effect prevents the powdering and breaking of the electrode material, ensures the integrity of the electrode, and maintains the electrical contact between the active material and the current collector. At the same time, the protective layer of inert material isolates the direct contact between the active material layer and the electrolyte, reducing the corrosion of the active material by the electrolyte. The production process is simple, low difficulty, no additional equipment is required, the production cost is low, there is no pollution to the environment, and the safety performance is high, making large-scale commercial use possible.

Preferably, the current collector in the current collector layer is copper foil.

Preferably, the lithium intercalation active material layer includes a lithium intercalation active material, a first conductive agent and a first binder, wherein the weight percentage of the lithium intercalation active material is 60% to 90%, and the The weight percentage of the first conductive agent is 5%-35%, and the weight percentage of the first binder is 5%-35%.

Preferably, the lithium-intercalating active material is an alloy negative electrode material with a single microscopic morphology or a mixture of alloy negative electrode materials with multiple microscopic morphology.

Preferably, the thickness of the lithium-deintercalation active material layer should be a moderate value within the range of 3-30 μm. Regarding the thickness of the deintercalated lithium active material layer, if it is too thin, it will easily break under the action of stress, and if it is too thick, it will cause a large impedance, and at the same time, the actual utilization rate of the active material to participate in the electrochemical reaction will decrease.

Preferably, the protective layer of inert material includes an inert protective substance, a second conductive agent and a second binder, wherein the weight percentage of the inert protective substance is 60% to 90%, and the weight of the second conductive agent The percentage is 5%-35%, and the weight percentage of the second binder is 5%-35%.

Preferably, the inert protective substance includes: polypyrrole nanowires, polyaniline nanofibers, polythiophene fibers, etc., which do not undergo lithium deintercalation reactions within the range of cyclic voltage, and have good elasticity and conductivity. polymer fibers.

Preferably, the thickness of the protective layer of inert material should be a moderate value within the range of 3-30 μm. The thickness of the protective layer of inert material should not be too thick, otherwise it will increase the transmission distance of lithium ions and reduce the ability of active materials to participate in electrochemical reactions, and it should not be too thin, otherwise the protective layer of inert material will be easily broken and lose its protective effect.

Preferably, the first conductive agent and/or the second conductive agent is a carbon material, including at least one of carbon black, acetylene black, Ketjen black, carbon fiber, carbon tube, and graphene.

Preferably, the first binder and the second binder cannot be both water-based or organic-based, so as to prevent interlayer penetration. Preferably, the first binder is an organic binder, and the second binder is a water-based binder; or, the first binder is a water-based binder, and the second binder is a water-based binder. The second binder is an organic binder. The organic binder may be polyvinylidene fluoride and/or polytetrafluoroethylene, and the aqueous binder may be at least one of hydroxymethyl cellulose, styrene-butadiene rubber, and sodium alginate.

Preferably, the three-layer electrode structure is formed by pressing sequentially stacked current collector layer, deintercalation lithium active material layer, and inert material protective layer under a pressure of 4-10 MPa. After the three-layer electrode is subjected to a certain pressure, the contact between the layers is closer, the contact resistance and interface resistance are reduced, and the polarization of the electrode is reduced, which is conducive to improving the electrochemical performance.

Preferably, there is a gradient distribution formed between the de-intercalating lithium active material layer and the inert material protective layer due to the pressure of pressing so that the de-intercalating lithium active material layer and the inert material protective layer are partially dissolved. Transition layer: in the gradient distribution transition layer, from the side close to the inert material protection layer to the side close to the deintercalation lithium active material layer, the inert protection material is distributed in a gradient decreasing manner. Preferably, the thickness of the gradient distribution transition layer is nanoscale.

Due to the physical compatibility of the inert protective layer and the active material layer, during the pressing process, the interface between the two layers becomes no longer obvious and there is mutual dissolution in a very small range, and the inert protective material appears in this area Gradient distribution, the closer the material solubility is to the active layer, the lower, and the thickness of this gradient transition layer increases with the degree of compression.

The existence of the gradient distribution transition layer is not only beneficial to reduce the interface impedance, but also a bridge connecting the protective layer and the active layer. When the active material layer is broken during the cycle, it can provide channels for the inert layer in time and repair the broken active layer. , so as to better play the protective effect of the inert layer.

Moreover, since this gradient distribution transition layer exists on the surface of the shallow layer of the active layer, the permeated inert material has good elasticity, which can relieve the stress of breaking the active layer to a certain extent and reduce the degree of damage to the active layer.

Therefore, the existence of the gradient distribution transition layer further strengthens the protection effect.

In view of the inherent volume expansion effect of the alloy negative electrode, the present invention no longer only focuses on the microstructure of the electrode material itself, but from the perspective of process structure design, adopts a three-layer electrode structure, and introduces an inert material protective layer on the surface of the active material layer. Relieve the stress to improve the electrochemical performance of the material, reduce the process difficulty and cost of the synthetic material, and provide the possibility to promote the practical application of the alloy negative electrode.

Description of drawings

Fig. 1 is the structural representation of the three-layer electrode structure of an example of the present invention;

Fig. 2 is the cross-sectional schematic diagram of above-mentioned three-layer electrode structure;

FIG. 3 is a schematic diagram of the front enlarged structure of the above-mentioned three-layer electrode structure;

Among them, 1 is the current collector layer, 2 is the active material layer for releasing lithium, 3 is the transition layer with gradient distribution, and 4 is the protective layer of inert material.

detailed description

The present invention will be further described below in conjunction with the drawings and the following embodiments. It should be understood that the drawings and the following embodiments are only used to illustrate the present invention rather than limit the present invention.

The invention provides a three-layer electrode structure for the negative electrode of a lithium ion battery. The three-layer electrode includes three layers of a current collector layer, a lithium deintercalation active material layer, and an inert material protective layer stacked in sequence.

The current collector layer is composed of a current collector, and the current collector can be a commonly used lithium ion battery negative electrode current collector, such as copper foil or nickel foil. The thickness of the current collector layer is not particularly limited, and the selection principle is based on low commercial price and cost reduction.

The lithium release active material layer located on the surface of the current collector layer includes a lithium release active material, a first conductive agent and a first binder, wherein the weight percentage of the lithium release active material can be 60% to 90%, The weight percentage of the first conductive agent may be 5%-35%, the weight percentage of the first binder may be 5%-35%, and the ratio of each component is acceptable within a certain range.

Wherein, the lithium-intercalating active material may be an alloy negative electrode with a single microscopic morphology or a mixture of alloy negative electrodes with multiple microscopic morphology. Also, the alloy used is not limited, for example, it may be Sn, Sb, Si, Ge, etc. and related oxides or alloys formed with other non-lithium metals.

The first conductive agent can be a carbon material, which can be one or a mixture of conductive carbon materials such as carbon black, acetylene black, and Ketjen black, or carbon materials such as carbon fibers, carbon tubes, and graphene with excellent electrical conductivity.

The first binder may be an organic binder such as polyvinylidene fluoride or polytetrafluoroethylene, or may be an aqueous binder such as hydroxymethyl cellulose, styrene-butadiene rubber, or sodium alginate.

The thickness of the lithium-deintercalation active material layer is not particularly limited, but it should not be too thin or too thick. Too thin is easy to break under stress, and too thick will cause a large impedance, and at the same time reduce the actual utilization rate of the active material to participate in the electrochemical reaction. , for example, a suitable value within the range of 3-30 μm, and a small fluctuation outside this range is acceptable.

The preparation method of the deintercalated lithium active material layer is not limited, for example, it can be prefabricated by coating following the traditional lithium ion battery manufacturing process. Specifically, it can be prepared by mixing the lithium-deintercalation active material, the first conductive agent, the first binder, and a certain amount of solvent to form a slurry, coating it on the surface of the current collector layer, drying it in vacuum, and removing the solvent. Deintercalation of the lithium active material layer. Wherein the selection of the solvent is related to the first binder, if the first binder is an organic binder, an organic solvent, such as N-methylpyrrolidone, etc. can be used, if the first binder is a water-based binder, Water can be used as the solvent.

Using the traditional manufacturing process of lithium-ion batteries avoids the waste of resources, saves costs, and does not need to improve the equipment. The new process maximizes the retention of the original equipment.

The inert material protection layer located on the surface of the deintercalation lithium active material layer includes an inert protection material, a second conductive agent and a second binder, wherein the weight percentage of the inert protection material can be 60% to 90%, and the first The weight percentage of the second conductive agent may be 5%-35%, and the weight percentage of the second binder may be 5%-35%.

Wherein, the inert protective substance can be a high molecular polymer fiber that does not undergo lithium intercalation and deintercalation reactions within the range of cyclic voltage, and has good elasticity and conductivity at the same time. For example, inert protective substances include but are not limited to: polypyrrole nanowires, polyaniline nanofibers, polythiophene fibers, etc., which do not undergo lithium deintercalation reactions within the range of cyclic voltages, and have good elasticity and conductivity. fiber.

The protective layer of inert material is located on the surface of the active material layer, and its fiber network structure effectively relieves the internal stress of the deintercalated lithium alloy negative electrode due to the volume effect, prevents the powdering and breaking of the electrode material, ensures the integrity of the electrode, and maintains the activity. The electrical contact of the material with the current collector. At the same time, the protective layer of inert material isolates the direct contact between the active material layer and the electrolyte, reducing the corrosion of the active material by the electrolyte.

The thickness of the protective layer of the inert material is not particularly limited, but it should not be too thick, otherwise it will increase the transmission distance of lithium ions and reduce the ability of the active material to participate in the electrochemical reaction, and it should not be too thin, otherwise the protective layer of the inert material will be easily broken and lost. Effectiveness, for example, is a suitable value in the range of 3 to 30 μm, and a small fluctuation outside this range is acceptable.

The second conductive agent can be a carbon material, which can be one or a mixture of conductive carbon materials such as carbon black, acetylene black, and Ketjen black, or carbon materials such as carbon fibers, carbon tubes, and graphene with excellent electrical conductivity.

It should be understood that the second conductive agent in the inert material protective layer and the first conductive agent in the lithium-deintercalation active material layer may be the same conductive agent, or different conductive agents may be selected.

The second binder may be an organic binder such as polyvinylidene fluoride or polytetrafluoroethylene, or may be an aqueous binder such as hydroxymethyl cellulose, styrene-butadiene rubber, or sodium alginate. However, it should be noted that the deintercalation lithium active material layer and the inert material protective layer should use different systems of binders to prevent mutual dissolution between layers, for example, the first binder may be an organic system binder. agent, and the second binder is a water-based binder; or, the first binder is a water-based binder, and the second binder is an organic binder.

The preparation method of the inert material protective layer is not limited, for example, it can be prefabricated by coating using the same lithium ion battery manufacturing process. Specifically, an inert protective substance, a second conductive agent, a second binder, and a certain amount of solvent may be mixed to form a slurry, coated on the surface of the lithium-deintercalation active material layer, dried in vacuum, and the solvent removed, to obtain Obtain a protective layer of inert material. Wherein the selection of solvent is related to the second binder, if the second binder is an organic binder, an organic solvent, such as N-methylpyrrolidone, etc. can be used, if the second binder is a water-based binder, Water can be used as the solvent.

By using the same lithium-ion battery coating process to prefabricate the protective layer of inert materials, the difficulty and complexity of the process can be greatly reduced, the industrialization process can be simplified, no additional equipment is required, and the manufacturing cost can be greatly reduced.

In a more preferred embodiment, a three-layer electrode structure is formed by pressing the sequentially stacked current collector layer, lithium deintercalation active material layer, and inert material protective layer under a specified pressure. The prescribed pressure may be 4 to 10 MPa.

After the three-layer electrode is subjected to a certain pressure, the contact between the layers is closer, the contact resistance and interface resistance are reduced, and the polarization of the electrode is reduced, which is conducive to improving the electrochemical performance.

In this case, due to the physical compatibility of the inert protective layer and the active material layer, during the pressing process, the interface between the two layers becomes no longer obvious, and there is mutual dissolution in a very small range to form a gradient distribution transition layer , the inert protective substance has a gradient distribution in this region, and the closer to the active layer, the lower the solubility of the substance, and the thickness of the transition layer of this gradient distribution increases with the degree of compression. For example, the thickness of the transition layer with gradient distribution is nanoscale.

Fig. 1 shows a schematic structural view of the three-layer electrode structure, and Fig. 2 shows a schematic cross-sectional view of the above-mentioned three-layer electrode structure, as shown in Fig. 1 and Fig. The lithium intercalation active material layer 2 and the inert material protective layer 4 , and a gradient distribution transition layer 3 exists between the lithium intercalation active material layer 2 and the inert material protective layer 4 . In addition, the three-layer electrode structure can be formed in a cuboid block shape, but it can also be in other shapes. FIG. 3 shows a schematic diagram of the front enlarged structure of the above-mentioned three-layer electrode structure. This surface is an inert material protective layer 4, which is the layer that is in contact with the electrolyte when assembled into a lithium-ion battery.

The existence of the gradient distribution transition layer 3 is not only beneficial to reduce the interfacial impedance, but also a bridge connecting the inert material protective layer 4 and the deintercalated lithium active material layer 2. When the active material layer 2 is broken during the cycle, it can be inert. 4 provides channels to repair the broken active layer 2, so as to better exert the protective effect of the inert layer 4.

Since the gradient distribution transition layer 3 exists on the surface of the shallow layer of the active layer 2, the permeated inert material has good elasticity, which can relieve the stress of the broken active layer 2 to a certain extent, and reduce the damage degree of the active layer 2.

Therefore, the existence of the gradient distribution transition layer 3 further strengthens the protection effect.

The lithium ion negative electrode provided by the present invention adopts a three-layer electrode structure, and the protective layer of inert material is located on the surface of the active material layer, and its fiber network structure effectively relieves the internal stress caused by the volume effect of the deintercalated lithium alloy negative electrode and prevents the pulverization of the electrode material , breaking, ensuring the integrity of the electrode and maintaining the electrical contact between the active material and the current collector. At the same time, the protective layer of inert material isolates the direct contact between the active material layer and the electrolyte, reducing the corrosion of the active material by the electrolyte. The production process is simple, low difficulty, no additional equipment is required, the production cost is low, there is no pollution to the environment, and the safety performance is high, making large-scale commercial use possible.

Examples are given below to describe the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention all belong to the present invention scope of protection. The specific process parameters and the like in the following examples are only examples of suitable ranges, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values exemplified below.

Comparative example 1

Mix SnO ₂ (Sinopharm Chemical Reagent Co., Ltd.), acetylene black and polyvinylidene fluoride pre-dissolved in N-methylpyrrolidone at a mass ratio of 9:0.5:0.5 to make a slurry, and coat it on a 15 μm thick copper foil 1. Vacuum drying at 100° C. to obtain the deintercalated lithium active material layer 2 , which is pressed under a pressure of 6 MPa to form an electrode. Lithium metal foil is used as the counter electrode and reference electrode, the polypropylene film of Celgard Company of the United States is used as the separator, 1M LiPF ₆ /(ethylene carbonate + dimethyl carbonate, 1:1) is used as the electrolyte, and the voltage is 0.05-1.5V Within the range, charge and discharge experiments were carried out at a current density of 0.1C. The test results are shown in Table 1.

Comparative example 2

SnO ₂ , acetylene black and polyvinylidene fluoride pre-dissolved in N-methylpyrrolidone were mixed at a mass ratio of 6:2:2 to make a slurry. The electrode preparation, battery assembly and testing conditions were the same as in Comparative Example 1. The test results are shown in Table 1.

Example 1

The preparation of the deintercalated lithium active material layer 2 is the same as that of Comparative Example 1. Mix polypyrrole nanowires, acetylene black, and sodium alginate pre-dissolved in water at a mass ratio of 9:0.5:0.5 to make a slurry, apply it to the deintercalation lithium active material layer 2, and dry it under vacuum at 70°C to make it inert The protective layer 4 is pressed into a three-layer electrode by 6MPa pressure. The battery assembly and test conditions are the same as in Comparative Example 1. The test results are shown in Table 1.

Example 2

The preparation of the deintercalated lithium active material layer 2 is the same as that of Comparative Example 1. Polypyrrole nanowires, acetylene black and sodium alginate pre-dissolved in water are mixed to form a slurry at a mass ratio of 6:2:2. The preparation of the electrode is the same as Example 1. The battery assembly and test conditions are the same as in Comparative Example 1. The test results are shown in Table 1.

Example 3

The preparation of the deintercalated lithium active material layer 2 is the same as that of Comparative Example 2, and the preparation of the inert protective layer 4 is the same as that of Example 1. The battery assembly and test conditions are the same as in Comparative Example 1. The test results are shown in Table 1.

Example 4

The preparation of the deintercalated lithium active material layer 2 is the same as that of Comparative Example 2, and the preparation of the inert protective layer 4 is the same as that of Example 2. The battery assembly and test conditions are the same as in Comparative Example 1. The test results are shown in Table 1.

The test result of table 1 comparative example 1～2 and embodiment 1～4

It can be seen from the data listed in Table 1 that the three-layer electrode structure designed by the present invention can effectively improve the cycle stability of the alloy negative electrode material, and the reversible specific capacity is still stably maintained above ^600mAh ·g after 100 cycles . According to SEM detection, the thickness of the deintercalated lithium active material layer 2 is about 3 μm, and the thickness of the inert protective layer 4 is about 6 μm.

Industrial applicability:

The three-layer electrode structure for the lithium ion battery alloy negative electrode of the present invention provides the possibility to promote the practical application of the alloy negative electrode, and the manufacturing process is simple, the difficulty is low, no additional equipment is required, the production cost is low, there is no pollution to the environment, and the safety performance is high. Large-scale commercial use becomes possible.

Claims (9)

1. a kind of alloys for anode materials of Li-ion battery triple electrode structure is it is characterised in that described triple electrode structure includes leading to Current collector layers, removal lithium embedded active material layer and the inert material protective layer crossed compacting and stack gradually；Described inert material protection Layer has inertia Protective substances, and described inertia Protective substances are removal lithium embedded reaction not to occur in the range of cyclical voltage and has bullet Property and the high polymer fiber of electric conductivity, deposit between described removal lithium embedded active material layer and described inert material protective layer The ladder making described removal lithium embedded active material layer and described inert material protective layer partial miscibility and being formed in the pressure because of compacting Degree distribution transition zone；In described Gradient distribution transition zone, take off from close to described inert material protective layer side to close to described Embedding lithium active material layer side, described inertia Protective substances successively decrease distribution in gradient；

Described inert material protective layer includes inertia Protective substances, the second conductive agent and the second binding agent, and wherein said inertia is protected The percentage by weight of shield material is 60%～90%, and the percentage by weight of described second conductive agent is 5%～35%, described second bonding The percentage by weight of agent is 5%～35%；

The thickness of described inert material protective layer is 3～30 μm.

2. alloys for anode materials of Li-ion battery according to claim 1 with triple electrode structure it is characterised in that described deintercalation Lithium active material layer includes removal lithium embedded active substance, the first conductive agent and the first binding agent, wherein said removal lithium embedded active substance Percentage by weight be 60%～90%, the percentage by weight of described first conductive agent is 5%～35%, the weight of described first binding agent Amount percentage ratio is 5%～35%.

3. alloys for anode materials of Li-ion battery according to claim 1 with triple electrode structure it is characterised in that described deintercalation Lithium active substance is that have the alloy material of cathode of single microscopic appearance or have multiple microscopic appearance alloy material of cathode Mixture.

4. alloys for anode materials of Li-ion battery according to claim 1 with triple electrode structure it is characterised in that described deintercalation The thickness of lithium active material layer is in the range of 3～30 μm.

5. alloys for anode materials of Li-ion battery according to claim 1 with triple electrode structure it is characterised in that described inertia Protective substances include: at least one in polypyrrole nano line, polyaniline nano fiber and polythiophene fiber.

6. alloys for anode materials of Li-ion battery according to claim 2 with triple electrode structure it is characterised in that described first Conductive agent and/or described second conductive agent are material with carbon element, including at least one in white carbon black, carbon fiber, carbon pipe and Graphene.

7. alloys for anode materials of Li-ion battery according to claim 2 with triple electrode structure it is characterised in that described first A side in binding agent and the second binding agent adopts water-based binder, and the opposing party adopts organic system binding agent, described water system bonding Agent is at least one in hydroxymethyl cellulose, butadiene-styrene rubber and sodium alginate, and described organic system binding agent is Kynoar And/or politef.

8. alloys for anode materials of Li-ion battery according to claim 1 with triple electrode structure it is characterised in that described three layers Electrode structure is to suppress the current collector layers stacking gradually, removal lithium embedded active material layer and inertia material under the pressure of 4～10mpa Material protective layer forms.

9. alloys for anode materials of Li-ion battery according to claim 8 with triple electrode structure it is characterised in that described gradient The thickness of distribution transition zone is nanoscale.