CN104868126A - Conductive substrate, electrode, energy storing device and preparation method thereof - Google Patents

Abstract

The conductive substrate, electrode, energy storage device and energy storage device preparation method provided by the present invention, the conductive substrate includes a non-conductive substrate layer and a conductive layer arranged on the non-conductive substrate layer, and the non-conductive substrate layer is 0.1-100 micron thick, porosity 40%-60%, excellent flexibility, self-supporting, high temperature and corrosion resistant plastic or rubbery polymer film or composite polymer film layer, the conductive layer The particle size of the conductive material layer is nanoscale, and the thickness of the conductive layer is 1-300 microns. The conductive substrate of the present invention includes a flexible non-conductive substrate layer and a conductive layer, and the purpose of increasing the flexibility of the substrate and thus the electrode flexibility is achieved by coating the conductive layer on the flexible non-conductive substrate layer.

Description

Conductive substrate, electrode, energy storage device and preparation method of energy storage device

technical field

The invention belongs to the field of electrical storage devices, and in particular relates to a conductive substrate, an electrode, an energy storage device and a preparation method for the energy storage device.

Background technique

The battery is manufactured by winding or laminating the positive electrode, negative electrode, separator, etc. Wherein the positive electrode and the negative electrode are respectively composed of positive electrode active material, negative electrode active material and conductive substrate (collector). In order to develop flexible battery products, it is necessary to improve the flexibility of the internal components of the battery.

Conventional batteries include both inflexible and flexible outer structures with little flexibility. The main reason for the poor flexibility of the battery with a flexible outer structure is the poor flexibility of the positive and negative electrodes inside the battery, and one of the main reasons for the poor flexibility of the positive and negative electrodes is the poor flexibility of the metal conductive substrate, multi-layer winding or lamination After that, the battery almost loses its flexibility. At the same time, since the conductive base material is made of pure metal, it has the risk of breaking, deforming and wrinkling. Therefore, how to design a flexible conductive base material has become a research topic for those skilled in the art.

Contents of the invention

In view of this, the present invention aims to propose a flexible conductive substrate, an electrode, an energy storage device and a preparation method of the energy storage device to solve the problem of battery flexibility.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

A conductive base material, comprising a non-conductive substrate layer and a conductive layer arranged on the non-conductive substrate layer, the non-conductive substrate layer is 0.1-100 microns thick, with a porosity of 40%-60%, excellent flexibility self-supporting and high temperature and corrosion resistant plastic or rubbery polymer film layer or composite polymer film layer, the conductive layer is a conductive material layer with a particle size of nanoscale, and the thickness of the conductive layer is 1-300 microns.

The non-conductive substrate layer is a single-layer or multi-layer film layer or a metal-plastic composite film layer composed of one or more of PP, PE, PVC or PET.

The conductive layer is combined with the non-conductive substrate layer by printing, coating, surface deposition or modification.

An electrode having the above-mentioned conductive substrate.

The conductive substrate is a patterned structure with holes and holes.

An energy storage device having the electrodes described above.

The method for preparing the above-mentioned electricity storage device is characterized in that: comprising the following steps:

s1. Preparation of conductive substrate: coating conductive paste on the non-conductive substrate layer;

s2. Ingredients of active substances;

s3. Coating:

s31. Select a conductive substrate with a thickness of 1.1-400 microns for the positive and negative electrodes;

s32. Coating an active material layer on the positive and negative electrode conductive substrates;

s33. After the coating is completed, the positive electrode is rolled to the design thickness with a hydraulic rolling machine after the pole piece is dried;

s4. Producer:

s41. Cut the positive and negative electrodes according to the size requirements;

s42. Clean a certain area at both ends of the positive and negative electrodes, and weld the tabs that can draw current on this area;

s5 assembly:

s51. The negative electrode is located in the middle of the diaphragm, the positive electrode is located in the middle of the negative electrode, the diaphragm separates the positive and negative electrodes, and the winding machine is used for winding or lamination; the winding core after winding or lamination is made of corrosion-resistant and high-temperature resistant The termination tape is pasted and formed, and the positive and negative electrode tabs of the core are aligned;

s52. Cover the roll core completed in step s41 with the cut aluminum-plastic film, and then use a top and side sealing machine to seal the top and side edges, leaving one side unsealed.

S53. Vacuumize and bake the winding core completed in step s42 for 12-16 hours at a temperature of 70°C, then inject electrolyte solution into the glove box, side seal the edge retained in step s52, and then leave it to age at room temperature for 8 -24h.

In the step s2, the viscosity of the positive and negative electrode slurries reaches 2000 cp in an environment of 25-30 degrees.

The pole piece coated in step s3 is dried until the weight loss is less than 100 ppm.

The drying method is thermal drying, infrared or ultraviolet drying.

Compared with the prior art, the electrode of the present invention has the following advantages:

(1) The conductive base material of the present invention includes a flexible non-conductive substrate layer and a conductive layer, and the purpose of increasing the flexibility of the substrate and thereby improving the flexibility of the electrode is achieved by coating a conductive layer on the flexible non-conductive substrate layer;

(2) The conductive base material of the present invention has a patterned structure with holes and holes, which further enhances the flexibility of the electrode;

(3) The conductive substrate of the present invention makes the rechargeable battery have good flexibility, and the degree of bendability is greatly increased; the non-conductive substrate layer can avoid metal burrs during processing and use, and reduce the probability of battery short circuit, so The safety of the battery can be improved; the cost of non-conductive substrate layers such as plastics is lower than that of metal materials, the manufacture is simple, and the use and processing are convenient; at the same time, the weight of the battery product is reduced, and the weight specific energy of the battery is improved.

Description of drawings

The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is a schematic structural view of a conductive substrate of the present invention;

Fig. 2 is a schematic illustration of various holes and hole patterned structures of the conductive substrate of the present invention;

Fig. 3 is a diagram showing the coating effect of pole pieces in Example 1 of the present invention.

Explanation of reference signs:

1- Conductive layer, 2- Non-conductive substrate layer.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

The present invention will be described in detail below with reference to the accompanying drawings and examples.

The conductive base material includes a non-conductive flexible substrate layer and a conductive layer. The non-conductive layer and the conductive layer together form a conductive substrate, as a part of the electrode, providing a transfer path for the electrons collected by the electrode.

The flexible substrate layer includes a certain thickness, a certain porosity, excellent flexibility (can be bent at will), and a self-supporting, high temperature and corrosion resistant flexible polymer film or polymer layer, such as polyethylene, polypropylene, polychloride Polyolefins such as ethylene and all flexible polymers that can be used in this invention;

The conductive layer is made of one or more metals (such as copper, aluminum, nickel, etc.) or non-metals (such as graphite), binders (such as PVDF (polyvinylidene fluoride), SBR (carboxylated styrene-butadiene latex), CMC (sodium carboxymethylcellulose), etc.), solvents (such as NMP (N-methylpyrrolidone), purified water, etc.);

The conductive layer is printed, coated, surface-deposited, modified or otherwise chemically or physically combined with the non-conductive layer and maintained as a whole;

The conductive layer and the non-conductive layer can be a continuous film layered structure, or a discontinuous layered structure, such as a surface patterned structure or a porous structure (as shown in Figure 2)

The conductive substrate has good flexibility, can be bent reversibly and has no risk of breaking, deforming and wrinkling;

The positive electrode, negative electrode or others and their components prepared by using the conductive base material, and the energy storage device containing the conductive base material all have good flexibility.

Process method:

A flexible polymer diaphragm or multi-layer composite film is used as a flexible substrate layer, the thickness of the substrate layer is 0.1-100 microns, and the substrate layer material can be PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride) One or more layers Polymer film or polymer composite film can also be metal/plastic composite film, such as aluminum-plastic film.

A thin layer of conductive metal paste or non-metal (such as graphite) is coated on the substrate layer, and the thickness of the thin layer may be less than or equal to 300 microns. The main component of the metal paste contains one or more of copper, aluminum, nickel, silver, zinc, etc., and the particle size is at the nanometer level. The coating method adopts printing, coating, surface deposition, modification or other chemical or physical methods. The coated pole piece is dried by heat drying, infrared or ultraviolet drying and other methods until the weight loss is less than 100ppm.

The conductive substrate has both flexibility and conductivity, and can directly replace the conductive substrates of positive and negative electrodes. After coating the positive and negative active materials, the substrate still has good flexibility. The raw material of the invention is the raw material used in any rechargeable battery;

The batching process of this invention is basically consistent with the traditional battery, and the formula contains electrode active materials (for example, the positive electrode is: lithium cobaltate, lithium nickelate, lithium manganate, lithium iron phosphate, ternary lithium ion active materials in different proportions or Nickel hydroxide, etc.; negative electrode: artificial or natural graphite, graphene, hydrogen storage alloy, metal cadmium or zinc, etc.); conductive agent SP (carbon black conductive agent), VGCF (ultrafine carbon fiber), SFG-6 (conductive carbon), carbon nanotubes, etc.; binders PVDF (polyvinylidene fluoride), SBR (carboxylated styrene-butadiene latex), CMC (sodium carboxymethylcellulose), etc.), solvents (such as NMP (N-methylpyrrolidone), Water, etc. and auxiliary reagents such as oxalic acid, etc. It is advisable to keep the viscosity of the slurry at about 2000cP.

The coating process uses extrusion, spraying, dimple, deposition or printing coating methods to coat the active material on the conductive substrate;

The flexible packaging battery can be made by using the conductive substrate coated with the active material, and the battery can have good flexibility.

Example 1:

Lithium-ion rechargeable bezel battery (size 0420100)

The battery can be installed in the space of the watch strap. Due to the softness of the battery, it can be well integrated with the watch strap and can be bent at will, which not only saves space but also increases the aesthetics, and provides power for the watch.

Preparation of conductive substrate:

Using a PE film with a thickness of 10 microns and a porosity of about 55% as the substrate layer of the conductive substrate can make the conductive substrate more flexible. In order to improve the temperature resistance of the substrate layer, the substrate layer is coated with aluminum oxide glue to form a ceramic substrate layer as a whole. The temperature resistance of the substrate layer can reach more than 200 degrees, and the heat shrinkability is good.

Aluminum paste and copper paste are respectively coated on the substrate layer by printing and coating, the front and back of one substrate are coated with aluminum paste, and the front and back of one substrate are both coated with copper paste. Use aluminum powder and copper powder with nanometer particle size respectively, add solvent NMP and adhesive PVDF to them, stir the slurry to achieve good fluidity, and can form a uniform conductive coating of 10 microns on the upper and lower substrate layers . Dry the conductive substrate at a temperature of 100 degrees until the weight loss is less than 100ppm, and set it aside.

Active material batching: the weight percent of each component is as follows:

Positive electrode: lithium cobaltate (97.95%), carbon nanotubes (1%), PVDF (1%), oxalic acid (0.05%);

Negative electrode: artificial graphite (95.98%), SP (1%), PVDF (3%), oxalic acid (0.02%);

Add the solvent NMP with a concentration of 95%-105% respectively, and use a double planetary vacuum mixer. After the two double planetary mixers are fully stirred, dispersed and cooled, the viscosity is adjusted so that the viscosity of the positive and negative electrode slurry is at 2000cp at 25-30°C; positive and negative electrode slurries are filtered with 150-mesh sieve for later use;

Coating:

The thickness of the positive electrode is selected to be 20 μm, and the ready-to-use aluminum conductive substrate has been prepared; the thickness of the negative electrode is selected to be 20 μm, and the ready-to-use copper conductive substrate has been prepared. The positive and negative electrode slurry is uniformly coated by an automatic coating machine and extrusion coating. The coating surface density is set to 32mg/cm2, the baking temperature is 90°C, and the coating speed is adjusted until the weight loss of the electrode coming out of the oven is less than 1000ppm, which is dry. After the pole piece is dried, use a hydraulic rolling machine to roll the positive electrode to a design thickness of 90-93 μm, and roll the negative electrode to 120-123 μm. The coating effect is shown in Figure 3;

Producer:

The size of the positive electrode is 150mm (length)*92mm (width);

The size of the negative electrode is 170mm (length) * 93mm (width);

Manufacture the sheet according to the above size to ensure the dimensional accuracy of ±0.2mm, then clean out a 4*4mm area at both ends of the electrode, and weld the tab on which the current can be drawn. The tab is 2mm*0.1mm positive electrode aluminum Tabs and negative electrode nickel tabs;

assembly:

The base film is a diaphragm uniformly coated with ceramic aluminum oxide and polyvinylidene fluoride on a single-layer polyolefin. The thickness of the diaphragm is 18 μm, and the length is 400mm*width 95mm;

The outer packaging is imported aluminum-plastic film of 210mm*50mm*86μm;

The negative electrode is located in the middle of the separator, the positive electrode is located in the middle of the negative electrode, the separator separates the positive and negative electrodes, and the winding is carried out by a plug-in winding machine; Align the positive and negative electrode tabs and tab glue. Cover the roll core with the cut aluminum-plastic film, and then use a top and side sealing machine to seal the top and side edges, leaving one side unsealed.

The sealed cells were vacuum-baked at 70°C for 16 hours, and then 5g of LiPF6 electrolyte was injected into the glove box, and the side-sealed edges were left to stand and aged at room temperature for 20 hours.

full capacity

A flexible and bendable watch ring battery is obtained after pre-full capacity of the aged battery cell.

Batteries of this size and shape made by traditional techniques cannot be bent;

The battery of this size and shape produced by the present invention can be bent at will.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. a conductive base, it is characterized in that: comprise non-conductive substrate layer and be located at the conductive layer on described non-conductive substrate layer, described non-conductive substrate layer is 0.1-100 micron thickness, porosity is 40%-60%, excellent pliability and have self-supporting and the plastics of corrosion-and high-temp-resistant or rubbery feel polymer rete or composition polymer rete, described conductive layer is particle diameter is nano level conductive material layer, and the thickness of described conductive layer is 1-300 micron.

2. electrode according to claim 1, is characterized in that: described non-conductive substrate layer is one or more single or multiple lift rete formed or metallo-plastic composite films in PP, PE, PVC or PET.

3. electrode according to claim 1, is characterized in that: described conductive layer is combined with non-conductive substrate layer by printing, coating, surface deposition or the method for modification.

4. there is the electrode of the conductive base as described in any one of claim 1-3.

5. electrode according to claim 4, is characterized in that: described conductive base is the pattern structure with hole, hole.

6. there is the energy storage device of the electrode as described in claim 4 or 5.

7. prepare the method for electric storage device according to claim 6, it is characterized in that: comprise the steps:

Prepared by s1, conductive base: coated with conductive slurry on non-conductive substrate layer;

S2, active material are prepared burden;

S3, coating:

S31. positive and negative electrode chooses the conductive base of 1.1-400 micron thickness;

S32. on positive and negative electrode conductive base, active material layer is applied;

S33. be coated with, pole piece adopts hydraulic pressure roller to roll positive electrode to design thickness after drying;

S4, film-making:

S41. positive and negative electrode is cut according to dimensional requirement;

S42. clean out certain region respectively at the two ends of positive and negative electrode, welding can the lug of extracted current on the area;

S5 assembles:

S51. negative electrode occupy barrier film middle, and positive electrode occupy negative electrode middle, and barrier film separates positive and negative electrode, adopts up-coiler to carry out reeling or lamination; Winding or lamination after core corrosion-resistant and high-temperature resistant terminal adhesive tape ending stickup shaping, core positive and negative electrode lug alignment;

S52. by the core that the aluminum plastic film encapsulation steps s41 cut out completes, then carry out banding limit, top side with top side seal machine, retain a side open-ended.

S53. the core completed step s42 at the temperature of 70 DEG C vacuumizes baking 12-16h, then in glove box, carries out injections electrolyte, at room temperature still aging 8-24h behind the limit of side seal step s52 reservation.

8. the preparation method of electrical storage device according to claim 7, is characterized in that: in described step s2, the viscosity of positive and negative electrode slurry is issued to 2000cp at 25-30 degree environment.

9. the preparation method of electrical storage device according to claim 7, is characterized in that: the pole piece in described step s3 after coating is dried to weightlessness and is less than 100ppm.

10. the preparation method of electrical storage device according to claim 9, is characterized in that: described drying means is heated drying, infrared or ultraviolet is dry.