CN108346523A - A kind of preparation method containing lithium an- ode of mixed type energy storage device - Google Patents

Abstract

The invention discloses a method for preparing a lithium-containing metal negative electrode of a hybrid energy storage device, which belongs to the technical field of electrochemical energy storage. Including: mixing and dispersing negative electrode active materials, elastic binders, conductive agents, additives, stabilized lithium powder, etc. to form a mixture; rolling the mixture to form a lithium-containing metal negative electrode film; coating the conductive glue A conductive viscous coating is formed on the current collector; the negative electrode film containing lithium metal and the current collector forming the conductive viscous coating are combined by hot pressing. The lithium-containing metal negative electrode film is matched with the positive electrode of the lithium-ion battery or the activated carbon electrode of the supercapacitor to make a lithium-ion battery or a lithium-ion capacitor. The invention can be used in the production process of high elastic electrodes such as the production of super capacitor pole pieces, the production of lithium ion battery pole pieces, the production of fuel cell pole pieces and the like. Large-scale production can be carried out, and there is no environmental pollution caused by solvent volatilization in the production process, the cost is greatly reduced, the production speed is fast, and the manufacturing cost is low.

Description

Preparation method of a lithium-containing metal negative electrode for a hybrid energy storage device

technical field

The invention relates to the technical field of electrochemical energy storage, in particular to a method for preparing a lithium-containing metal negative electrode of a hybrid energy storage device.

Background technique

Electrochemical power sources have been widely used as energy storage components. With the development of my country's power supply industry, the demand for electrochemical power sources is increasing, and its performance requirements are getting higher and higher. The electrode is the core of the chemical power supply, and the performance parameters of the electrode determine the performance of the power supply itself. The lithium-containing metal negative electrode is of great significance for the power supply based on the lithium ion intercalation and extraction reaction as the energy storage principle. The lithium-containing metal negative electrode is matched with the lithium-ion positive electrode to form a lithium-ion battery, which can greatly improve the first charge and discharge efficiency, and is of great help to improve the energy density of the battery. The lithium-containing metal negative electrode is matched with the activated carbon electrode to form a new type of energy storage device. The positive electrode stores energy through the surface adsorption charge, and the negative electrode stores energy through the insertion and extraction of lithium ions. Combining the principles of lithium-ion batteries and supercapacitors, the formation of Hybrid Energy Storage Devices - Li-ion Supercapacitors.

Contents of the invention

The object of the present invention is to provide a method for preparing a lithium-containing metal negative electrode for a hybrid energy storage device, which is characterized in that it includes the following steps:

(1) Mix and disperse the active material, elastic binder, conductive agent, and stabilized lithium powder to form a mixture; the total mass composition of the mixed and dispersed mixture includes: the elastic binder is 1 wt %-20 wt %, The conductive agent is 0.5 wt %-30 wt %, the active material is 50 wt %-98 wt %, and the stabilized lithium powder is 0.5 wt %-10 wt %;

(2) Rolling the mixed and dispersed mixture obtained in step (1) multiple times to form a negative electrode film containing lithium metal;

(3) Apply the conductive agent to the current collector to form a conductive viscous coating;

(4) Hot-compressing the current collector of the lithium-containing metal negative electrode film and the conductive adhesive coating to obtain a highly elastic lithium-containing metal negative electrode film;

(5) Match the negative electrode film containing lithium metal with the positive electrode of lithium ion battery or activated carbon electrode of supercapacitor to make lithium ion battery or lithium ion supercapacitor.

The active material is a powder with a particle size ranging from 0.1 μm to 2 μm, and the selected active material includes activated carbon, airgel carbon, carbon nanotubes, modified carbon nanotube materials, graphene, modified graphene materials, activated carbon and Graphene composite materials, activated carbon and carbon nanotube composite materials, mesocarbon microspheres, natural graphite, modified graphite, coated graphite, artificial graphite, coke, silicon powder, silicon wire Lithium-containing cathode for lithium-ion batteries One or more mixtures of powder materials, lithium-containing negative electrode powder materials used in lithium-ion battery negative electrodes.

The elastic binder is solid or powder with a molecular weight of 100,000 to 1 million, and EPDM rubber, acrylic resin, polytetrafluoroethylene, polyvinylidene fluoride, and styrene-butadiene rubber are selected. 1. One or more mixtures of nitrile rubber demethylcellulose sodium.

The conductive agent is powder, one or a mixture of acetylene black, Ketjen black, conductive fiber, conductive graphite, and metal wire.

The additive is a processing aid for rubber or plastic; and one or more mixtures of reinforcing agent, anti-aging agent, vulcanizing agent and plasticizer are selected.

The stable lithium metal powder is SLMP produced by FMC Corporation of the United States, with a purity of 97% and a size of 5 to 50 μm.

The mixing and dispersing method in the step 1) adopts open double-rod mixing and dispersing, single-screw sealed mixing and dispersing, twin-screw sealed mixing and dispersing, multi-screw sealed mixing and dispersing, double planetary mixing and dispersing, ball milling mixing and dispersing; The dispersion time is from 5 to 360 minutes.

The mixture in the step 2) is rolled using a hot rolling process; the rolling temperature is 120°C-200°C; the mixture is hot-rolled multiple times to form a continuous high-elastic lithium-containing metal negative electrode film.

The current collector is selected from copper foil, aluminum foil or viscous conductive polymer film.

The conductive adhesive is made into a paste by one or more of conductive carbon black, conductive graphite, graphene, and carbon nanotubes with a water-based binder or an oil-based binder, and is coated by gravure coating or wire bar coating. The cloth method forms a solid conductive adhesive coating on the surface of the current collector.

The beneficial effect of the present invention is that it can be used in the production process of highly elastic electrodes such as the production of supercapacitor pole pieces, the production of lithium ion battery pole pieces, and the production of fuel cell pole pieces. Large-scale production can be carried out, and there is no environmental pollution caused by solvent volatilization in the production process, the cost is greatly reduced, the production speed is fast, and the manufacturing cost is low.

Description of drawings

Figure 1 is a schematic flow chart of the preparation of highly elastic electrodes.

FIG. 2 is a scanning electron microscope image of the positive pole piece of Example 1. FIG.

FIG. 3 is a scanning electron microscope image of the negative pole piece of Example 2. FIG.

FIG. 4 is a charge-discharge curve diagram of the device in Example 3. FIG.

Detailed ways

The invention provides a method for preparing a lithium-containing metal negative electrode of a hybrid energy storage device, comprising the following steps:

(1) Mix and disperse the active material, elastic binder, conductive agent, additive and stabilized lithium powder to form a mixture;

(2) Rolling the mixed and dispersed mixture obtained in step (1) multiple times to form a negative electrode film containing lithium metal;

(3) Apply conductive adhesive to the current collector to form a conductive viscous coating;

(4) Hot-compressing the current collector of the lithium-containing metal negative electrode film and the conductive adhesive coating to obtain a highly elastic lithium-containing metal negative electrode film;

(5) Match the lithium-containing metal negative electrode film with the positive electrode of the lithium-ion battery or the activated carbon electrode of the supercapacitor to make a hybrid lithium-ion battery or a hybrid lithium-ion supercapacitor.

Figure 1 shows a schematic flow chart for the preparation of highly elastic electrodes. The preparation method of described highly elastic electrode comprises steps as follows:

1) First mix and disperse the active material, highly elastic binder, and conductive agent, and stabilize lithium powder to form a mixture; the total mass of the mixture includes 1 wt %-20 wt % of high elastic binder, conductive agent 0.5 wt %-30 wt %, active material 50 wt %-98 wt %, stabilized lithium powder 0.5 wt %-10 wt %.

2) Roll the mixed and dispersed mixture for about 5 to 360 minutes, and the rolling temperature is 120°C-200°C; heat the mixed material for many times to form a continuous high elastic activity Lithium-containing metal negative electrode film.

3) Apply conductive glue to form a conductive adhesive coating;

4) The highly elastic active material film and the current collector formed with a conductive viscous coating on the surface are hot-pressed and composited to obtain a highly elastic porous electrode.

The "highly elastic electrode" in the present invention refers to an electrode with high elastic performance that is piled up by small particles and adhered together by a high elastic binder, so as to facilitate the adaptation of the volume expansion and contraction of the material during the device assembly and reaction process. Adding a small amount of additives during electrode processing can improve the processing performance of the electrode, improve the flexibility of the electrode, and improve the environmental resistance of the electrode.

The "conductive agent" refers to a certain amount of conductive substance that is usually added to the electrode sheet to ensure good charge and discharge performance of the electrode, which acts as a means of collecting current between the active materials and between the active material and the current collector. The function is to reduce the contact resistance of the electrode to accelerate the transfer rate of electrons, absorb more electrolyte, and effectively increase the migration rate of ions in the electrode material, thereby improving the charge and discharge efficiency of the electrode.

The "conductive adhesive" refers to an adhesive that has a certain conductive function at a certain temperature after curing or drying; the conductive adhesive is made of one or more of conductive carbon black, conductive graphite, graphene, and carbon nanotubes. It is mixed with water-based binder or oil-based binder to make a paste, and coated on the surface of the current collector by gravure coating or wire bar coating to form a solid conductive adhesive coating.

The "collector" refers to a structure or part that collects current, and its function is mainly to collect the current generated by the electrochemically active material so as to form a larger current for external output. In the embodiments, the active substance is in the form of powder.

The active substance is a powder with a particle size ranging from 0.1 μm to 2 μm, including activated carbon, airgel carbon, carbon nanotubes, modified carbon nanotube materials, graphene, modified graphene materials, activated carbon and graphene composite materials , Activated carbon and carbon nanotube composite materials, mesocarbon microspheres, natural graphite, modified graphite, coated graphite, artificial graphite, coke, silicon powder, lithium-containing positive electrode powder materials used in lithium-ion batteries with silicon wires, One or more mixtures of lithium-containing negative electrode powder materials used in the negative electrode of lithium-ion batteries.

The highly elastic binder is solid or powder, preferably a binder with a molecular weight of 100,000 to 1 million, and includes EPDM rubber, acrylic resin, polytetrafluoroethylene, polyvinylidene fluoride, and styrene-butadiene rubber 1. One or more mixtures of nitrile rubber demethylcellulose sodium.

The conductive agent is powder; it includes one or a mixture of acetylene black, Ketjen black, conductive fiber, conductive graphite and metal wire.

The mixing and dispersing methods of the present invention include open double-rod mixing and dispersing, single-screw sealed mixing and dispersing, twin-screw sealed mixing and dispersing, multi-screw sealed mixing and dispersing, double planetary mixing and dispersing, and ball milling mixing and dispersing.

The current collector of the present invention adopts copper foil, aluminum foil or viscous conductive polymer film; and the conductive adhesive is coated on the surface of the current collector by gravure coating or wire bar coating to form a solid conductive adhesive coating.

Referring to the accompanying drawings, the present invention will be explained in detail through the following embodiments.

Example 1

Activated carbon produced by Korea PCT Company is used as the active material, its specific surface area is 1850 to 2150㎡/g, and D50 is 1-2μm.

The mesophase carbon microspheres produced by Shanghai Shanshan are used, with a mass specific capacity of 330mAh/g and an irreversible specific capacity of 20mAh/g.

The EPDM rubber particles produced by Dow in the United States are used as the binder, and its D50 is 0.25 μm.

Use Super P from Changzhou Temico Co., Ltd. as the conductive agent.

Use SN-307R produced by Zeon as the conductive adhesive.

Use the 2400 type separator produced by celgard as the battery separator

Use the stable metal lithium powder SLMP produced by the US FMC company

The activated carbon (active material) produced by the above-mentioned South Korean PCT company, the EPDM microparticles (bonding agent) produced by Dow, and the SP (conductive agent) produced by Changzhou Temegao Co., Ltd. were weighed by mass to stabilize metal lithium. powder SLMP, the mass ratio of which is 85:9.5:4.5:1, the above materials are dispersed by ball milling using a ball mill disperser, and the dispersion process is carried out for 60 minutes to obtain a 1kg dispersion mixture; the formed mixture is rolled by a hot press, rolled The temperature was 180°C, and the active material film was formed by rolling three times; the aluminum foil was used as the current collector, and the water-based conductive adhesive SN-307R was coated on the aluminum foil by the gravure coating method to form a conductive coating; the obtained active material film and formed Copper foil with conductive coating is compounded, and after the active material film and the solvent in the conductive adhesive are volatilized, a dry highly elastic porous electrode is formed. The scanning electron micrograph of the obtained highly elastic porous electrode pole piece is shown in FIG. 2 .

Example 2

Mesophase carbon microspheres produced by Shanghai Shanshan, EPDM microspheres produced by Dow, SP produced by Changzhou Temegao Co., Ltd., and SLMP stabilized lithium metal powder are weighed by mass, and the mass ratio is 90:7 : 2:1, the above materials are dispersed by ball milling using a ball mill disperser, and the dispersion process is carried out for 120 minutes to obtain a 1kg dispersion mixture; the formed mixture is rolled by a hot press at a temperature of 180°C and rolled three times to form an active Substance film; using copper foil as a current collector, the water-based conductive adhesive SN-307R is coated on the aluminum foil by gravure coating method to form a conductive coating; the obtained active material film and the copper foil of the conductive coating formed Composite, after the active material film and the solvent in the conductive adhesive evaporate completely, a dry highly elastic porous electrode will be formed. The scanning electron micrograph of the obtained highly elastic porous electrode pole piece is shown in FIG. 3 .

Example 3

The highly elastic porous electrode pole piece obtained in the above-mentioned embodiment 1 or embodiment 2 is cut into slices as the positive and negative pole pieces, assembled together with the diaphragm, and the subsequent welding, packaging, baking, liquid injection, Formation and testing procedures complete the fabrication of the device, and the charge and discharge curves of the device are shown in Figure 4.

Claims (10)

1. a kind of preparation method containing lithium an- ode of mixed type energy storage device, which is characterized in that include the following steps：

（1）Active material, elastic binder, conductive agent, stabilized lithium powder are subjected to mixing dispersion, to form mixture；It is mixed The gross mass of conjunction dispersed mixture, which forms, includes：Elastic binder is 1 wt %-20 wt %, and conductive agent is 0.5 wt %-30 Wt %, active material are 50 wt %-98 wt %, and stabilized lithium powder is 0.5 wt %-10 wt %；

（2）To step（1）Mixture after acquired mixing dispersion carries out multiple roll-in, to form film containing lithium an- ode；

（3）Conductive agent is applied and forms conductive adhesive coating on a current collector；

（4）The progress hot pressing of the collector of film containing lithium an- ode and conductive adhesive coating is compound, it obtains high resiliency and contains lithium metal Negative electrode film；

（5）Lithium an- ode film will be contained and make lithium ion with lithium ion cell positive or the matching of ultracapacitor activated carbon electrodes Battery or lithium ion super capacitor.

2. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute It is powder to state active material, 0.1 μm to 2 μm of particle size range, and it includes that activated carbon, aeroge charcoal, charcoal are received to choose active material Mitron, Modified Activated Carbon nano-tube material, graphene, modified graphene material, activated carbon and graphene composite material, activated carbon and charcoal Nanometer tube composite materials, carbonaceous mesophase spherules, natural graphite, modified graphite, coated graphite, artificial graphite, coke, silica flour, silicon The negative electrode powder containing elemental lithium that the positive pole powder material containing elemental lithium, the negative electrode of lithium ion battery that line lithium ion battery uses use The mixture of the one or more of body material.

3. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute It is solid or powder to state elastic binder, and molecular weight is 10 ten thousand to 100 ten thousand binder, and chooses ethylene-propylene-diene monomer One kind or one of glue, acrylic resin, polytetrafluoroethylene (PTFE), Kynoar, butadiene-styrene rubber, nitrile rubber demethyl sodium cellulosate Kind or more mixture.

4. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute It is powder, the mixing of acetylene black, the one or more of Ketjen black, conductive fiber, electrically conductive graphite, wire to state conductive agent Object.

5. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute It is rubber or plastic processing additives to state additive；And choose reinforcing agent, antiaging agent, vulcanizing agent, one kind of plasticizer or one Kind or more mixture.

6. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute The SLMP that stable metal lithium powder is the production of FMC Corp. of the U.S., purity 97% are stated, size is 5 to 50 μm.

7. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute State step 1）Mixing dispersing mode sealed using open double rods mixing dispersion, the sealed mixing dispersion of single screw rod, twin-screw Formula mixing dispersion, the sealed mixing dispersion of multiscrew, double planetary mixing dispersion, the mixing dispersion of ball milling formula；Mix jitter time It is 5 to 360 minutes.

8. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute State step 2）Mixture carry out roll-in use Hot-rolling process；Roll temperature is 120 DEG C -200 DEG C；Mixture is carried out repeatedly Hot-rolling pressure, to form continuous elastomeric film containing lithium an- ode.

9. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that institute It states collector and is selected from copper foil, aluminium foil or sticking conductive polymer film.

10. a kind of preparation method containing lithium an- ode of mixed type energy storage device according to claim 1, which is characterized in that The conducting resinl by one or more of conductive black, electrically conductive graphite, graphene, carbon nanotube with water-based binder or Oil system binder is tuned into paste, and forms solid-state like conduction in collection liquid surface by intaglio plate coating or bar rubbing method and glue Property coating.