TWI557970B - A composite material applied to the negative electrode of lithium ion battery and its preparation method - Google Patents

Description

Composite material applied to negative electrode of lithium ion battery and preparation method thereof

The invention belongs to a composite lithium ion battery material and a preparation method thereof, in particular to a composite lithium ion battery anode material composed of a ruthenium-based material, graphene, and amorphous carbon, and a preparation method thereof.

It is well known that the anode materials of lithium ion batteries are mostly graphite carbon, among which mesocarbon microbeads (MCMB) are most widely used, and the theoretical capacitance is 372 mAh/g, in order to seek high efficiency and low cost. Anode materials, many new anode materials have been developed, including non-graphitizable amorphous carbon, lithium titanate oxide, bismuth-based and tin-based composite materials, among which the high-capacity bismuth-based materials have the most development potential. The theoretical capacitance is up to 4200 mAh/g. However, in the process of charge and discharge of ruthenium-based anode materials, lithium ion intercalation and migration are accompanied by intense volume expansion and shrinkage (>300%), which will lead to disintegration and fragmentation of the electrode material, resulting in electrode structure. It is easy to loosen and pulverize, and the conductivity of the ruthenium-based material is low. Therefore, after repeated charge and discharge cycles, the intense volume change of the ruthenium-based material and the disintegration of the electrode will cause the capacitance to rapidly decay, thus limiting Its commercial application.

The main object of the present invention is to provide a composite material and a preparation method for a negative electrode of a lithium ion battery. The composite material composition of the present invention comprises a ruthenium-based material, graphene, and amorphous carbon, and the combination thereof is a core-shell structure, the most The inner layer is a ruthenium-based material, the middle layer is graphene, and the outermost layer is amorphous carbon. The composite material can effectively improve its structure and electrical conductivity, and effectively inhibit the volume expansion of the bismuth-based material. The composite material of the invention can be used in the fields of electric steam locomotives, smart handheld devices, tablet computers, cameras and energy storage devices.

The composite material of the invention, wherein the ruthenium-based material is a lithium ion battery anode material containing ruthenium or osmium alloy, the material may be tin-based material, cobalt trioxide, ferric oxide, titanium One of a group of lithium ion negative electrode materials such as a base material, an aluminum base material, a titanium oxide, or a combination thereof, wherein the amorphous carbon may be an amorphous carbon material such as sucrose, xylose or five carbon sugar.

The composition of the composite material of the present invention, wherein the content of the ruthenium-based material is 15% by weight to 50% by weight, the content of graphene is 2% by weight to 10% by weight, and the content of amorphous carbon is 40% by weight to 80% by weight.

A second object of the present invention is to provide a method for preparing a negative electrode material for a lithium ion battery, the preparation method comprising: (A) providing a negatively charged ruthenium-based material; (B) adding the negatively charged ruthenium-based material to an anhydrous In a polar organic solvent, a positively charged modifier is added, and the charge conversion reaction is carried out by heating and stirring in an oil bath, converting the negative charge of the ruthenium-based material into a positive charge, and drying to form a first material; (C) providing a negatively charged aqueous solution of graphene oxide; (D) adding the first material to the negatively charged aqueous solution of graphene oxide, heating and stirring in an oil bath, performing self-assembly of positive and negative charge attraction to form a second material; (E) providing an aqueous solution of glucose; (F) adding the second material to the aqueous glucose solution, stirring uniformly, placing it in an autoclave for hydrothermal process, heating and stirring in an oil bath to carry out hydrolysis and dehydration reaction, After cooling, the sample solution is taken out for filtration and cleaning, and then dried in an oven to obtain a third material; (G) the third material is placed in a high temperature furnace, and argon gas and hydrogen gas are introduced for high temperature reduction. Carbonation reaction, then after the hydrofluoric acid treatment, to obtain a composite material is applied to the negative electrode of a lithium ion battery.

11~17‧‧‧ A method for preparing a negative electrode composite material for a lithium ion battery

1 is a schematic view showing a process of a composite nano graphite-supporting carbon-niobium-ion battery material according to an embodiment of the present invention.

2 is a first charge and discharge map of different amounts of glucose/graphene/amorphous carbon electrode in the embodiment of the present invention.

Figure 3 is a graph showing the cycle life and coulombic efficiency of charging/discharging (30 cycles) of different glucose-added yttrium/graphene/amorphous carbon electrodes according to an embodiment of the present invention.

Figure 4 is a diagram showing the first charge and discharge pattern of a VC assisting agent 矽/graphene/amorphous carbon electrode in the embodiment of the present invention.

Figure 5 is a diagram showing the cycle life and coulombic efficiency map of a VC assisting agent 矽/graphene/amorphous carbon charge and discharge (50 cycles) according to an embodiment of the present invention.

Figure 6 is a diagram showing the addition of a VC auxiliary agent to different amounts of graphene oxide in the embodiment of the present invention. Graphene/amorphous carbon first ring charge and discharge map

Figure 7 is a graph showing the charge and discharge (50 cycles) and coulombic efficiency of a VC assisting agent 矽/graphene/amorphous carbon electrode with different amounts of graphene oxide added in the embodiment of the present invention.

The invention provides a composite material applied to a negative electrode of a lithium ion battery, which is a core-shell structure comprising: an innermost layer of a ruthenium-based material, wherein the ruthenium-based material is a tin-based material, a cobalt trioxide, a ferric oxide, One of a group of a titanium-based material, an aluminum-based material, a titanium oxide, or a combination thereof; an intermediate layer of graphene, the graphene coating the innermost layer of germanium-based material; an outermost layer of amorphous carbon, the amorphous The carbon layer coats the graphene of the intermediate layer, wherein the amorphous carbon is one of a group of amorphous carbon materials of glucose, sucrose, xylose, or five carbon sugars, or a combination thereof.

In the composite material of the negative electrode of the lithium ion battery of the present invention, the content of the cerium-based material is 15 wt% to 50 wt%, the content of graphene is 2 wt% to 10 wt%, and the content of glucose is 40 wt% to 80 wt%.

The invention further provides a method for preparing a composite material applied to a negative electrode of a lithium ion battery, comprising: (A) as shown in FIG. 1, step 11, providing a negatively charged germanium-based material, wherein the germanium-based material is a tin-based material, One of a group of tricobalt tetroxide, ferric oxide, a titanium-based material, an aluminum-based material, titanium oxide, or a combination thereof; (B) as shown in FIG. 1, step 12, adding the negatively charged ruthenium-based material to an anhydrous portion In a non-polar organic solvent, a positively-charged modifier is added, and the charge-conversion reaction is carried out by heating and stirring in an oil bath, the negative charge of the ruthenium-based material is converted into a positive charge, and the first material is formed by centrifugation, wherein the water is not changed. The non-polar organic solvent may be one of a group of toluene, hexane, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, dichloromethane or a combination thereof, and the positively charged modifier is aminopropyltriethoxy One of a group of aminopropyltriethoxysilane (APS), polydiethylenedimethylammonium chloride (PDDA), poly(diallydimethylammonium chloride), aminooxane modifier, cationic modifier, or a combination thereof; (C) as the first Step 13, providing a negatively charged aqueous graphene oxide solution; (D) as shown in Figure 1, step 14, adding the first material to the negatively charged aqueous graphene oxide solution, heating and stirring in an oil bath, for positive and negative Self-assembly of charge attraction to form a second material The method of self-assembly is spray drying or vapor deposition; (E) as shown in Figure 1, step 15, providing an aqueous solution of glucose; (F) as in Figure 1, step 16, the second The material is added to the aqueous glucose solution, stirred uniformly, and placed in an autoclave having a temperature of 150 ° C to 200 ° C for hydrothermal process, and then heated and stirred in an oil bath to carry out hydrolysis and dehydration reaction, and after cooling, take out The sample solution is filtered and cleaned, and then dried in an oven to obtain a third material, wherein the hydrothermal process is a wet chemical process, a thermal reduction process, a solvothermal reduction process, a microwave hydrothermal process, or a microwave solvent. Thermal reduction process; (G) as shown in Fig. 1, step 17, the third material is placed in a high temperature furnace, argon gas, hydrogen gas is passed through for high temperature reduction and carbonization reaction, and then treated with hydrofluoric acid to obtain a The composite material applied to the negative electrode of the lithium ion battery, wherein the high temperature reduction heating temperature ranges from 300 ° C to 1100 ° C.

In the preparation method of the present invention, the content of the cerium-based material is preferably from 50 to 80% by weight, and the carbon content is from 20 to 50% by weight.

The following is a specific embodiment for describing the method of applying the present invention, and measuring the capacitance, the first cycle coulomb efficiency, and the cycle life of the lithium ion battery to specifically illustrate the advantages and effects of the present invention.

Embodiment 1

1.5 g of ruthenium particles were taken into a 200 ml anhydrous toluene solution, and after ultrasonic vibration for 1 hour, the mixed solution was placed in an oil bath and stirred continuously while raising the temperature to 40 ° C, and an inert gas (Ar) was introduced. 2 ml of aminopropyl-triethoxysilane solution (APS) was injected, and after stirring for 24 hours, the sample was collected by a centrifuge, and washed several times with alcohol, and then vacuum-dried in an oven at 60 ° C to obtain The ruthenium particles are added to the graphene aqueous solution, stirred and mixed with a magnet, and further heated to 40 ° C in an oil bath, and stirred for 24 hours to obtain a modified bismuth/graphene oxide (Si-modified/GO) mixed solution. At this time, the weight ratio of the modified bismuth/graphene oxide (Si-modified/GO) was 1:10. A 100 ml glass sample vial was used as a container, and an appropriate weight of glucose (Glucose) was dissolved in 10 ml of ion water (DI water), and stirred at room temperature for 30 minutes until completely dissolved. The granule/graphene oxide mixed solution was poured into a glucose aqueous solution sample bottle (矽: graphene: glucose weight ratio: 0.5:0.05:0.45) and uniformly stirred for 10 minutes, and the sample bottle was placed in an autoclave (autoclave). Cover the lock. The oil bath was heated to 180 ° C in advance on a stirring heater, and then the autoclave was placed at the center of the oil bath and stirred at 400 rpm. After the temperature of the crucible is raised to the reaction temperature (180 ° C), the hydrolysis and dehydration reaction are carried out for 6 hours while the reaction is completed. After the completion of the reaction, the stirring and heating device are turned off, and the mixture is cooled at room temperature. After cooling, the sample solution was taken out and washed with alcohol (EtOH) and ion water (DI water) until the filtrate was colorless and transparent, and placed in an oven at 60 ° C under vacuum to obtain a brownish black powder. The powder is placed in a tubular high-temperature furnace in an alumina crucible, vacuumed, and then introduced into H ₂ /Ar gas, and heated to 5 ° C / min to 800 ° C for 2 hours for sintering reduction, and then cooled by natural cooling. The sample is taken out for use. Finally, a thin layer of cerium oxide in the composite material is removed by diluting the solution with 10% hydrofluoric acid (HF) to obtain a composite material of ruthenium, graphene and amorphous carbon, which is used for the anode of the lithium ion battery, wherein the ruthenium content is It accounts for 78% by weight and the carbon content accounts for 22% by weight. After the material was packaged into a button cell, the electrochemical analysis was carried out, and the capacitance capacity of the material was measured to be 2514 mAh/g, the Coulomb efficiency of the first circle was 80%, and the cycle life of 30 cycles was 47%, as shown in Figures 2 and 3.

Embodiment 2

1.5 g of ruthenium particles were taken into a 200 ml anhydrous toluene solution, and after ultrasonic vibration for 1 hour, the mixed solution was placed in an oil bath and stirred continuously while raising the temperature to 40 ° C, and an inert gas (Ar) was introduced. 2 ml of aminopropyl-triethoxysilane solution (APS) was injected, and after stirring for 24 hours, the sample was collected by a centrifuge, and washed several times with alcohol, and then vacuum-dried in an oven at 60 ° C to obtain The ruthenium particles were added to the graphene aqueous solution, stirred and mixed with a magnet, and heated to 40 ° C in an oil bath. After stirring for 24 hours, a modified bismuth/graphene oxide (Si-modified/GO) mixed solution was obtained. This successfully synthesized material is referred to as A1 in the present invention, and the weight ratio of the modified bismuth/graphene oxide (Si-modified/GO) is 1:10. A 100 ml glass sample vial was used as a container, and an appropriate weight of glucose (Glucose) was dissolved in 10 ml of ion water (DI water), and stirred at room temperature for 30 minutes until completely dissolved. The granule/graphene oxide mixed solution was poured into a glucose aqueous solution sample bottle (矽: graphene: glucose weight ratio: 0.5:0.05:0.9) and uniformly stirred for 10 minutes, and the sample bottle was placed in an autoclave (autoclave). Cover the lock. The oil bath was heated to 180 ° C in advance on a stirring heater, and then the autoclave was placed at the center of the oil bath and stirred at 400 rpm. After the temperature of the crucible is raised to the reaction temperature (180 ° C), the hydrolysis and dehydration reaction are carried out for 6 hours while the reaction is completed. After the completion of the reaction, the stirring and heating device are turned off, and the mixture is cooled at room temperature. After cooling, the sample solution was taken out and washed with alcohol (EtOH) and ion water (DI water) until the filtrate was colorless and transparent, and placed in an oven at 60 ° C under vacuum to obtain a brownish black powder. The powder was placed in a tubular high-temperature furnace in an alumina crucible, evacuated, and then subjected to H ₂ /Ar (5/100 sccm) gas, and heated at 5 ° C / min to 800 ° C for 2 hours to carry out sintering reduction, and then After the natural cooling method is cooled, the sample is taken out for use. Finally, a thin layer of cerium oxide in the composite material is removed by diluting the solution with 10% hydrofluoric acid (HF) to obtain a composite material of ruthenium, graphene and amorphous carbon, which is used for the anode of the lithium ion battery, wherein the ruthenium content is It accounts for 64% by weight and the carbon content is 36% by weight. After the material was packaged into a button cell, the electrochemical analysis was carried out, and the capacitance of the material was measured to be 1663 mAh/g, the Coulomb efficiency of the first circle was 75.9%, and the cycle life of 30 cycles was 44%, as shown in Figures 2 and 3.

Embodiment 3

1.5 g of ruthenium particles were taken into a 200 ml anhydrous toluene solution, and after ultrasonic vibration for 1 hour, the mixed solution was placed in an oil bath and stirred continuously while raising the temperature to 40 ° C, and an inert gas (Ar) was introduced. 2 ml of aminopropyl-triethoxysilane solution (APS) was injected, and after stirring for 24 hours, the sample was collected by a centrifuge, and washed several times with alcohol, and then vacuum-dried in an oven at 60 ° C to obtain The ruthenium particles were added to the graphene aqueous solution, stirred and mixed with a magnet, and heated to 40 ° C in an oil bath. After stirring for 24 hours, a modified bismuth/graphene oxide (Si-modified/GO) mixed solution was obtained. This successfully synthesized material is referred to as A1 in the present invention, and the weight ratio of the modified bismuth/graphene oxide (Si-modified/GO) is 1:10. A 100 ml glass sample vial was used as a container, and an appropriate weight of glucose (Glucose) was dissolved in 10 ml of ion water (DI water), and stirred at room temperature for 30 minutes until completely dissolved. The granule/graphene oxide mixed solution was poured into a glucose aqueous solution sample bottle (矽: graphene: glucose weight ratio: 0.5:0.05:0.18) and uniformly stirred for 10 minutes, and the sample bottle was placed in an autoclave (autoclave). Cover the lock. The oil bath was heated to 180 ° C in advance on a stirring heater, and then the autoclave was placed at the center of the oil bath and stirred at 400 rpm. After the temperature of the crucible is raised to the reaction temperature (180 ° C), the hydrolysis and dehydration reaction are carried out for 6 hours while the reaction is completed. After the completion of the reaction, the stirring and heating device are turned off, and the mixture is cooled at room temperature. After cooling, the sample solution was taken out and washed with alcohol (EtOH) and ion water (DI water) until the filtrate was colorless and transparent, and placed in an oven at 60 ° C under vacuum to obtain a brownish black powder. The powder was placed in a tubular high-temperature furnace in an alumina crucible, evacuated, and then subjected to H ₂ /Ar (5/100 sccm) gas, and heated at 5 ° C / min to 800 ° C for 2 hours to carry out sintering reduction, and then After the natural cooling method is cooled, the sample is taken out for use. Finally, a thin layer of cerium oxide in the composite material is removed by diluting the solution with 10% hydrofluoric acid (HF) to obtain a composite material of ruthenium, graphene and amorphous carbon, which is used for the anode of the lithium ion battery, wherein the ruthenium content is It accounts for 51% by weight and the carbon content is 49% by weight. The material was packaged into a button cell and its electrochemical analysis was carried out. The capacitance of the material was measured to be 1363 mAh/g, the first cycle Coulomb efficiency was 63.9%, and the 30 cycle life was 50%, as shown in Figures 2 and 3.

Embodiment 4

1.5 g of ruthenium particles were taken into a 200 ml anhydrous toluene solution, and after ultrasonic vibration for 1 hour, the mixed solution was placed in an oil bath and stirred continuously while raising the temperature to 40 ° C, and an inert gas (Ar) was introduced. 2 ml of aminopropyl-triethoxysilane solution (APS) was injected, and after stirring for 24 hours, the sample was collected by a centrifuge, and washed several times with alcohol, and then vacuum-dried in an oven at 60 ° C to obtain The ruthenium particles were added to the graphene aqueous solution, stirred and mixed with a magnet, and heated to 40 ° C in an oil bath. After stirring for 24 hours, a modified bismuth/graphene oxide (Si-modified/GO) mixed solution was obtained. This successfully synthesized material is referred to as A1 in the present invention, and the weight ratio of the modified bismuth/graphene oxide (Si-modified/GO) is 1:10. A 100 ml glass sample vial was used as a container, and an appropriate weight of glucose (Glucose) was dissolved in 10 ml of ion water (DI water), and stirred at room temperature for 30 minutes until completely dissolved. The granule/graphene oxide mixed solution was poured into a glucose aqueous solution sample bottle (矽: graphene: glucose weight ratio: 0.5:0.05:0.45) and uniformly stirred for 10 minutes, and the sample bottle was placed in an autoclave (autoclave). Cover the lock. The oil bath was heated to 180 ° C in advance on a stirring heater, and then the autoclave was placed at the center of the oil bath and stirred at 400 rpm. After the temperature of the crucible is raised to the reaction temperature (180 ° C), the hydrolysis and dehydration reaction are carried out for 6 hours while the reaction is completed. After the completion of the reaction, the stirring and heating device are turned off, and the mixture is cooled at room temperature. After cooling, the sample solution was taken out and washed with alcohol (EtOH) and ion water (DI water) until the filtrate was colorless and transparent, and placed in an oven at 60 ° C under vacuum to obtain a brownish black powder. The powder was placed in a tubular high-temperature furnace in an alumina crucible, evacuated, and then subjected to H ₂ /Ar (5/100 sccm) gas, and heated at 5 ° C / min to 800 ° C for 2 hours to carry out sintering reduction, and then After the natural cooling method is cooled, the sample is taken out for use. Finally, a thin layer of cerium oxide in the composite material is removed by diluting the solution with 10% hydrofluoric acid (HF) to obtain a composite material of ruthenium, graphene and amorphous carbon, which is used for the anode of the lithium ion battery, wherein the ruthenium content is It accounts for 78% by weight and the carbon content accounts for 22% by weight. The material was packaged into a button cell, and an additional 2 wt% VC (Vinylene carbonate) promoter was added to the electrolyte to measure its electrochemical analysis. The capacitance of the material was measured to be 2670 mAh/g, and the first cycle Coulomb efficiency was 77%, 50 cycles. The cycle life is 56.3%, as shown in Figures 4 and 5.

Embodiment 5

1.5 g of ruthenium particles were taken into a 200 ml anhydrous toluene solution, and after ultrasonic vibration for 1 hour, the mixed solution was placed in an oil bath and stirred continuously while raising the temperature to 40 ° C, and an inert gas (Ar) was introduced. 2 ml of aminopropyl-triethoxysilane solution (APS) was injected, and after stirring for 24 hours, the sample was collected by a centrifuge, and washed several times with alcohol, and then vacuum-dried in an oven at 60 ° C to obtain The ruthenium particles were added to the graphene aqueous solution, stirred and mixed with a magnet, and heated to 40 ° C in an oil bath. After stirring for 24 hours, a modified bismuth/graphene oxide (Si-modified/GO) mixed solution was obtained. This successfully synthesized material is referred to as A1 in the present invention, and the weight ratio of the modified bismuth/graphene oxide (Si-modified/GO) is 1:10. A 100 ml glass sample vial was used as a container, and an appropriate weight of glucose (Glucose) was dissolved in 10 ml of ion water (DI water), and stirred at room temperature for 30 minutes until completely dissolved. The granule/graphene oxide mixed solution was poured into a glucose aqueous solution sample bottle (矽: graphene: glucose weight ratio: 0.5:0.1:0.45) and uniformly stirred for 10 minutes, and the sample bottle was placed in an autoclave (autoclave). Cover the lock. The oil bath was heated to 180 ° C in advance on a stirring heater, and then the autoclave was placed at the center of the oil bath and stirred at 400 rpm. After the temperature of the crucible is raised to the reaction temperature (180 ° C), the hydrolysis and dehydration reaction are carried out for 6 hours while the reaction is completed. After the completion of the reaction, the stirring and heating device are turned off, and the mixture is cooled at room temperature. After cooling, the sample solution was taken out and washed with alcohol (EtOH) and ion water (DI water) until the filtrate was colorless and transparent, and placed in an oven at 60 ° C under vacuum to obtain a brownish black powder. The powder was placed in a tubular high-temperature furnace in an alumina crucible, evacuated, and then subjected to H ₂ /Ar (5/100 sccm) gas, and heated at 5 ° C / min to 800 ° C for 2 hours to carry out sintering reduction, and then After the natural cooling method is cooled, the sample is taken out for use. Finally, a thin layer of cerium oxide in the composite material is removed by diluting the solution with 10% hydrofluoric acid (HF) to obtain a composite material of ruthenium, graphene and amorphous carbon, which is used for the anode of the lithium ion battery, wherein the ruthenium content is It accounts for 75 wt% and the carbon content accounts for 25 wt%. The material was packaged into a button cell, and an additional 2 wt% (Vinylene carbonate) promoter was added to the electrolyte to measure its electrochemical analysis. The capacitance of the material was measured to be 2137 mAh/g, and the first cycle Coulomb efficiency was 73.1%, 50 cycles. The life expectancy is 82.1%, as shown in Figures 6 and 7.

Embodiment 6

1.5 g of ruthenium particles were taken into a 200 ml anhydrous toluene solution, and after ultrasonic vibration for 1 hour, the mixed solution was placed in an oil bath and stirred continuously while raising the temperature to 40 ° C, and an inert gas (Ar) was introduced. 2 ml of aminopropyl-triethoxysilane solution (APS) was injected, and after stirring for 24 hours, the sample was collected by a centrifuge, and washed several times with alcohol, and then vacuum-dried in an oven at 60 ° C to obtain The ruthenium particles were added to the graphene aqueous solution, stirred and mixed with a magnet, and heated to 40 ° C in an oil bath. After stirring for 24 hours, a modified bismuth/graphene oxide (Si-modified/GO) mixed solution was obtained. This successfully synthesized material is referred to as A1 in the present invention, and the weight ratio of the modified bismuth/graphene oxide (Si-modified/GO) is 1:10. A 100 ml glass sample vial was used as a container, and an appropriate weight of glucose (Glucose) was dissolved in 10 ml of ion water (DI water), and stirred at room temperature for 30 minutes until completely dissolved. The granule/graphene oxide mixed solution was poured into a glucose aqueous solution sample bottle (矽: graphene: glucose weight ratio: 0.5:0.15:0.45) and uniformly stirred for 10 minutes, and the sample bottle was placed in an autoclave (autoclave). Cover the lock. The oil bath was heated to 180 ° C in advance on a stirring heater, and then the autoclave was placed at the center of the oil bath and stirred at 400 rpm. After the temperature of the crucible is raised to the reaction temperature (180 ° C), the hydrolysis and dehydration reaction are carried out for 6 hours while the reaction is completed. After the completion of the reaction, the stirring and heating device are turned off, and the mixture is cooled at room temperature. After cooling, the sample solution was taken out and washed with alcohol (EtOH) and ion water (DI water) until the filtrate was colorless and transparent, and placed in an oven at 60 ° C under vacuum to obtain a brownish black powder. The powder was placed in a tubular high-temperature furnace in an alumina crucible, evacuated, and then subjected to H ₂ /Ar (5/100 sccm) gas, and heated at 5 ° C / min to 800 ° C for 2 hours to carry out sintering reduction, and then After the natural cooling method is cooled, the sample is taken out for use. Finally, a thin layer of cerium oxide in the composite material is removed by diluting the solution with 10% hydrofluoric acid (HF) to obtain a composite material of ruthenium, graphene and amorphous carbon, which is used for the anode of the lithium ion battery, wherein the ruthenium content is It accounts for 62% by weight and the carbon content is 38% by weight. The material was packaged into a button cell, and an additional 2 wt% VC (Vinylene carbonate) promoter was added to the electrolyte to measure its electrochemical analysis. The capacitance of the material was measured to be 2101 mAh/g, and the first cycle Coulomb efficiency was 62.7%, 50 cycles. The cycle life is 74.2%, as shown in Figures 6 and 7.

The above-described embodiments are merely illustrative of the features and functions of the present invention, and are not intended to limit the scope of the technical scope of the present invention.

11~17‧‧‧Steps for preparing a composite material for a negative electrode of a lithium ion battery

Claims (11)

A composite material applied to a negative electrode of a lithium ion battery, the combination of which is a core-shell structure comprising: an innermost layer of a ruthenium-based material, wherein the ruthenium-based material is a tin-based material, a cobalt trioxide, a ferric oxide, a titanium-based material One of a group of aluminum-based materials, titanium oxide, or a combination thereof; an intermediate layer of graphene, the graphene coating the innermost layer of germanium-based material; an outermost layer of amorphous carbon, the amorphous carbon coating the The intermediate layer of graphene, wherein the amorphous carbon is one of a group of glucose, sucrose, xylose, or a five carbon sugar amorphous carbon material, or a combination thereof. The composite material according to claim 1, wherein the content of the ruthenium-based material is 15 wt% to 50 wt%, the content of graphene is 2 wt% to 10 wt%, and the content of glucose is 40 wt% to 80 wt%. A method for preparing a composite material for a negative electrode of a lithium ion battery, comprising: (A) providing a negatively charged ruthenium-based material; (B) adding the negatively charged ruthenium-based material to an anhydrous non-polar organic solvent, And adding a positive charge modifier, heating and stirring in an oil bath to carry out a charge-transfer reaction, converting the negative charge of the ruthenium-based material into a positive charge, and drying to form a first material; (C) providing a negatively charged oxidation (D) adding the first material to the negatively charged aqueous solution of graphene oxide, heating and stirring in an oil bath, performing self-assembly of positive and negative charge attraction to form a second material; (E) providing a (F) adding the second material to the aqueous glucose solution, stirring uniformly, placing it in an autoclave for hydrothermal process, heating and stirring in an oil bath to carry out hydrolysis and dehydration reaction, and after cooling, taking out the sample The solution is filtered and cleaned, and then dried in an oven to obtain a third material; (G) the third material is placed in a high temperature furnace, and argon gas, hydrogen gas is introduced for high temperature reduction and carbonization reaction, and then hydrogen is passed. After the acid treatment, to obtain a composite material is applied to the negative electrode of a lithium ion battery. The method of claim 3, wherein the bismuth-based material is one of a group consisting of a tin-based material, a cobalt trioxide, a ferric oxide, a titanium-based material, an aluminum-based material, a titanium oxide, or a combination thereof. The method of claim 3, wherein the anhydrous non-polar organic solvent is toluene, hexane, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, dichloromethane or a combination thereof. One of the groups. The method of claim 3, wherein the positively charged modifier is aminopropyltriethoxysilane (APS), polydiallyldimethylammonium chloride (PDDA, poly( One of a group of diallydimethylammonium chloride), an aminooxane modifier, a cationic modifier, or a combination thereof. The method of claim 3, wherein the self-assembly method is a spray drying method or a vapor deposition method. For example, the method described in claim 3, wherein the hydrothermal process is a wet chemical process, a thermal reduction process, a solvothermal reduction process, a microwave hydrothermal process, or a microwave solvothermal process. The method of claim 3, wherein the heating temperature of the hydrothermal process in the step (F) ranges from 150 ° C to 200 ° C. For example, in the third aspect of the patent application, a method for preparing a composite material for a negative electrode of a lithium ion battery, wherein the heating temperature in the high temperature reduction in the step (G) ranges from 300 ° C to 1100 ° C. A method for preparing a composite material for a negative electrode of a lithium ion battery, comprising: (A) providing a negatively charged germanium-based material, wherein the germanium-based material is a tin-based material, a cobalt trioxide, a ferric oxide, a titanium-based material, One of a group of aluminum-based materials, titanium oxide or a combination thereof; (B) adding the negatively charged sulfhydryl-based material to an anhydrous non-polar organic solvent, and adding a positively-charged modifier to heat in an oil bath Stirring to carry out a charge-transfer reaction, converting the negative charge of the ruthenium-based material into a positive charge, and drying to form a first material, wherein the anhydrous non-polar organic solvent is toluene, hexane, diethyl ether, chloroform, ethyl acetate, One of the groups of tetrahydrofuran, dichloromethane or a combination thereof, the positively charged modifier is aminopropyltriethoxysilane (APS), polydiallyldimethylammonium chloride (APS, aminopropyltriethoxysilane) One of a group of PDDA, poly(diallydimethylammonium chloride), an aminooxane modifier, a cationic modifier, or a combination thereof; (C) providing a negatively charged aqueous graphene oxide solution; (D) the first Material joining The negatively charged aqueous solution of graphene oxide is heated and stirred in an oil bath to perform self-assembly of positive and negative charge attraction to form a second material, wherein The method of self-assembly is spray drying or vapor deposition; (E) providing an aqueous solution of glucose; (F) adding the second material to the aqueous glucose solution, stirring uniformly, and placing the temperature in the kettle at 150 ° C. The hydrothermal process is carried out in an autoclave of ~200 ° C, and then heated and stirred in an oil bath to carry out hydrolysis and dehydration reaction. After cooling, the sample solution is taken out for filtration and cleaning, and then vacuum dried in an oven to obtain a third material, wherein The hydrothermal process is a wet chemical process, a thermal reduction process, a solvothermal reduction process, a microwave hydrothermal process, or a microwave solvothermal reduction process; (G) placing the third material in a high temperature furnace, A high temperature reduction and carbonization reaction is carried out by introducing argon gas and hydrogen gas, and then treated with hydrofluoric acid to obtain a composite material for use in a negative electrode of a lithium ion battery, wherein the high temperature reduction heating temperature ranges from 300 ° C to 1100 ° C.