WO2022166996A1

WO2022166996A1 - Method and apparatus for electrodepositing active material particles on electrode current collector

Info

Publication number: WO2022166996A1
Application number: PCT/CN2022/077556
Authority: WO
Inventors: 闫时建; 张敏刚; 郭锦
Original assignee: 太原科技大学
Priority date: 2021-02-05
Filing date: 2022-02-24
Publication date: 2022-08-11
Also published as: CN112981499B; CN112981499A

Abstract

Disclosed in the present invention are a method and apparatus for electrodepositing active material particles on an electrode current collector. The apparatus comprises an electrophoresis tank (2), wherein an electrolyte is contained in the electrophoresis tank (2), and solid particles to be deposited and the electrolyte form a sol; said solid particles are a substance or a mixture of a plurality of substances; a deposited conducting strip (5) vertically stands in the middle of the electrophoresis tank (2), and is connected to a positive electrode or a negative electrode of a direct-current power source (10), and a counter electrode (1) is divided into two parts, which are symmetrically distributed on two sides of the deposited conducting strip (5); the deposited conducting strip (5) is a flexible conducting strip or a non-flexible conducting strip; and the solid particles dispersed in the electrolyte are electrodeposited on two surfaces of the deposited conducting strip (5) by means of electrophoresis. By means of the present invention, an active material can be directly deposited on a flexible porous material, and continuous coating of a deposited conducting strip during a moving process can be realized by means of continuous electrodeposition.

Description

Method and apparatus for electrodepositing active material particles on electrode current collectors

technical field

The invention belongs to the field of lithium ion battery manufacturing, and in particular relates to a method and a device for coating an active material on an electrode current collector.

Background technique

The demand for better and wider adaptability has prompted people to continuously improve the materials and structures of lithium-ion batteries, and to improve production efficiency. The application of flexible electrode current collectors makes the process of coating active materials on current collectors more efficient. diversification. CN202010316327.5 discloses a method for electrodepositing a mixed phase of nano-carbon-doped MnO ₂ on the surface of a flexible conductive sheet, but MnO ₂ is reacted and precipitated from an electrolyte containing soluble MnSO ₄ , rather than in the electrolytic solution. The insoluble MnO ₂ particles are directly dispersed in the liquid, and the synergistic constant current electrodeposition method is adopted. The composition of the electrolyte and the auxiliary operation are complicated, and the current is small and the efficiency is low, so it has no wide applicability; in "Material Protection", 2005, No. 9 The article "Preparation of LiCoO ₂ Thin Films by Electrophoretic Deposition", published on , is limited to single electrodeposition of LiCoO ₂ particles on the surface of an inflexible conductive sheet such as aluminum foil, which not only results in low loading and coating efficiency due to single-sided electrodeposition , and the conductivity is insufficient to make it practical. The electrodeposition apparatuses designed by the published related patents are also quite different and all have shortcomings. In view of the deficiencies in the existing related literature, the present invention reasonably designs a set of devices for electrodepositing particles on conductive sheets, especially carbon-based flexible conductive sheets by using a DC power supply. A range of solid particles can be deposited, either single species or multiple species co-deposition, both cathode and anode can be deposited and both sides can be deposited simultaneously, or continuous deposition of the deposited conductive sheet moving through the electrolytic cell and The automatic feeding is realized, so as to prepare the positive electrode or negative electrode sheet containing the current collector used in the lithium ion battery, which has wide applicability, high efficiency and good effect.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method and device for electrodepositing active material particles on the electrode current collector of a lithium ion battery against the deficiencies of the prior art.

The technical scheme of the present invention is as follows:

A device for electrodepositing materials on an electrode current collector of a lithium ion battery, comprising an electrophoresis tank (2), an electrophoresis tank (2) containing an electrolyte, and solid particles to be deposited and the electrolyte to form a sol; The solid particles are one substance or a mixture of multiple substances; the deposited conductive sheet (5) stands vertically in the middle of the electrophoresis tank (2), is connected to the positive or negative electrode of the DC power supply (10), and divides the counter electrode (1). The two parts are symmetrically distributed on both sides of the deposited conductive sheet (5); the deposited conductive sheet (5) is a flexible conductive sheet or a non-flexible conductive sheet; the solid particles dispersed in the electrolyte are electrodeposited onto the deposited conductive sheet by electrophoresis. Deposit on the conductive sheet (5).

For the described device, in the case of co-deposition, if the solid particles of different substances to be deposited form colloidal particles with different electrical properties in the same dispersion liquid, it is necessary to selectively add electrolytes, stabilizers or surfactants to separate the different electrical properties. The colloidal particles are changed to be both positive or negative, and then perform cathodic electrophoresis or anodic electrophoresis to achieve co-deposition of various solid particles, and to improve the stability of the colloid and enhance the binding force between the particles and the deposited conductive sheet (5). ; If the solid particles of different substances to be deposited form colloidal particles of the same electrical property in the same dispersion liquid, co-deposition can be achieved without special treatment.

In the device, the output voltage of the DC power supply (10) is 0-200V.

The device is provided with slits (9) on the two side walls of the electrophoresis tank (2), and a normally closed soft one-way valve is arranged on the slits (9); The deposited conductive sheet (5) enters the electrophoresis tank (2) from a slit on one side, and exits the electrophoresis tank (2) from the slit on the other side, and the deposited conductive sheet (5) is in a moving state during the electrophoresis process.

In the described device, the electrolyte leaked from the slit (9) is collected in the electrolyte recovery tank (6), and sent back to the electrophoresis tank (2) by the liquid pump (4) through the electrolyte recovery pipe (3). ).

In the device, a magnetic rotor (8) is arranged in the electrophoresis tank (2), and the lower part of the electrophoresis tank (2) is a magnetic stirrer (7).

In the described device, a magnetic rotor (8) is arranged in the electrolyte recovery tank (6), and the lower part of the electrolyte recovery tank (6) is a magnetic stirrer (7).

In the device, the electrolyte solution is an inorganic or organic liquid that does not dissolve or react with the solid particles, and can form a sol with the solid particles.

In the device, the deposited conductive sheet (5) is a high-conductivity flexible loose material.

In the device, the deposited conductive sheet (5) is a carbon fiber woven cloth, and the solid particles are nano-sulfur.

The device also includes an automatic feeding system, including an incident light glass window (11), an outgoing light glass window (12), an optoelectronic excitation plate (13), an optoelectronic receiving plate (14), a cone plug (16), a funnel ( 17); the cone plug (16) is made of ferromagnetism, and the cone plug (16) is wound with a coil outside; the lower part of the funnel (17) is provided with a conical blanking hole that cooperates with the top of the cone on the vertebral plug (16), and the funnel ( 17) It is made of magnetic material; an incident light glass window (11) is arranged on one side wall of the electrophoresis tank (2), and an outgoing light glass window (12) is arranged on the opposite side wall, and the light beam passes through the incident light glass window (11). ), the outgoing light glass window (12) passes through the dispersion liquid and shoots onto the photoelectron excitation plate (13). The intensity of the light beam excites the photoelectrons on the photoelectron excitation plate (13) and strikes the photoelectron receiving plate (14), so that the automatic feeding control circuit is turned on so that the coil of the cone plug (16) is energized, and the cone plug (16) generates a magnetic field and repels it. The magnetic funnel (17) with the same magnetic polarity as the cone plug (16), the active material powder (18) falls into the electrophoresis tank (2) from the conical discharge hole, so that the concentration of the particles in the electrolyte increases, and the effect of the light beam is reduced. The increase in scattering reduces the intensity of the light beam enough to excite photoelectrons on the photoelectron excitation plate (13), the automatic feeding control circuit is disconnected, the taper plug (16) loses its magnetism, and the feeding opening of the funnel (17) is blocked to automatically stop feeding.

The device also includes an automatic feeding system, including an incident light glass window (11), an outgoing light glass window (12), an optoelectronic excitation plate (13), an optoelectronic receiving plate (14), a cone plug (16), a funnel ( 17); the cone plug (16) is made of magnetostrictive material; an incident light glass window (11) is arranged on one side wall of the electrophoresis tank (2), and an outgoing light glass window (12) is arranged on the opposite side wall , the light beam passes through the incident light glass window (11) and the outgoing light glass window (12), passes through the dispersion liquid, and hits the photoelectron excitation plate (13). When the scattering of the light beam is reduced, the light beam with sufficient intensity will excite the photoelectrons on the photoelectron excitation plate (13), hit the photoelectron receiving plate (14), and the automatic feeding control circuit is turned on, so that the magnetostrictive material wound around the coil is made of magnetostrictive material. The size of the manufactured cone plug (16) changes in the length direction, and there is a gap between the funnel (17) containing the active material powder (18) above, and the active material powder (18) will be supplemented into the electrolyte to make the electrolysis The concentration of particles in the liquid increases, and the scattering of the light beam increases, so that the intensity of the light beam is reduced enough to excite photoelectrons on the photoelectron excitation plate (13), the automatic feeding control circuit is disconnected, and the cone plug made of magnetostrictive material (16) The size is restored to its original state, and the feeding port of the funnel (17) is blocked to automatically stop feeding.

A method for electrodepositing material on an electrode current collector of a lithium ion battery, comprising the steps of:

Step A1, the electrophoresis tank (2) is filled with electrolyte, and the solid particles to be deposited and the electrolyte form a sol; the solid particles to be deposited are a substance or a mixture of multiple substances;

Step A2, standing the deposited conductive sheet (5) vertically in the middle of the electrophoresis tank (2), and connecting it with the positive or negative electrode of the DC power supply (10);

In step A3, the counter electrode (1) is divided into two parts and symmetrically distributed on both sides of the deposited conductive sheet (5); the deposited conductive sheet (5) is a flexible conductive sheet or a non-flexible conductive sheet;

Step A4: Turn on the power of the electrophoresis tank, and use electrophoresis to electrodeposit the solid particles dispersed in the electrolyte on both sides of the deposited conductive sheet (5).

In the described method, in step A1, if the solid particles to be deposited are solid particles of different substances, and different solid particles form colloidal particles with different electrical properties in the same dispersion liquid, it is necessary to selectively add electrolytes or surfactants. The colloidal particles with different electrical properties are changed to the same positive charge or the same negative charge.

The method, in step A1, further includes step A5, automatic feeding; an incident light glass window (11) is arranged on one side wall of the electrophoresis tank (2), and an outgoing light glass window (12) is arranged on the opposite side wall. ), the light beam passes through the incident light glass window (11) and the outgoing light glass window (12), passes through the dispersion, and strikes the photoelectron excitation plate (13). When the scattering of the light beam is reduced, the light beam with sufficient intensity will excite the photoelectrons on the photoelectron excitation plate (13) and hit the photoelectron receiving plate (14), so that the automatic feeding control circuit is turned on for feeding. The concentration of the particles increases, and the scattering of the light beam increases, so that the intensity of the light beam is reduced to be insufficient to excite photoelectrons on the photoelectron excitation plate (13), and the automatic feeding control circuit is disconnected.

A method for manufacturing a positive electrode sheet or a negative electrode sheet of a lithium ion battery, wherein a lithium ion battery electrode current collector is prepared according to any one of the described methods, the deposited conductive sheet (5) is a high-conductivity flexible loose material, and the electrode current collector is used as the basis to manufacture The positive electrode sheet or the negative electrode sheet eliminates the rolling process in the traditional electrode manufacturing process, and does not need to add conductive agents and binders, which simplifies the production process.

The advantages and positive effects of the present invention are:

1. The equipment is simple, the operation is convenient, and the production efficiency is high. It can simultaneously coat the active material particles on both sides of the deposited conductive sheet. The electrodeposition time is very short, generally no more than 10 minutes.

2. The active material can be deposited directly on the flexible loose material. After depositing the active material, there is no need to roll the electrode sheet to prepare the electrode sheet, and the wound cell will be naturally compacted to improve the energy density of the battery;

3. The deposited conductive sheet can be continuously coated in motion by continuous electrodeposition;

4. Active materials can be deposited directly on high-conductivity loose materials without adding conductive agents and binders, and it also adapts to the trend of electronic device flexibility.

Description of drawings

Fig. 1 is the schematic diagram of the device of the present invention, in the figure: 1-pair of electrodes; 2-electrophoresis tank; 3-electrolyte recovery pipe; 4-liquid pump; 5-deposited conductive sheet; 6-electrolyte recovery tank; 7-magnetic force Stirrer; 8-magnetic rotor; 9-slit; 10-DC power supply; 11-incident light glass window; 12-outgoing light glass window; 13-photoelectron excitation plate; 14-photoelectron receiving plate; 15-automatic feeding control circuit Power supply; 16-cone plug; 17-funnel; 18-active material powder.

Figure 2(a) is a scanning electron image of elemental sulfur particles electrodeposited on carbon cloth.

Figure 2(b) is the X-ray energy spectrum of electrodeposited elemental sulfur particles on carbon cloth.

Figure 2(c) is a graph showing the first charge-discharge curve of a lithium-sulfur battery at a rate of 0.1C with a cathode sheet prepared by electrodepositing elemental sulfur on carbon cloth.

Figure 3(a) is a scanning electron image of composite electrodeposited elemental sulfur and neodymium oxide particles on aluminum foil.

Figure 3(b) is the X-ray energy spectrum of composite electrodeposited elemental sulfur and neodymium oxide particles on aluminum foil.

Figure 3(c) is a graph showing the first charge-discharge curve of a lithium-sulfur battery at a rate of 0.1C in which the cathode sheet was prepared by compound electrodepositing elemental sulfur and neodymium oxide on aluminum foil.

Figure 4(a) is a scanning electron image of electrodeposited lithium iron phosphate particles on carbon cloth.

Figure 4(b) is the X-ray energy spectrum of electrodeposited lithium iron phosphate particles on carbon cloth.

Figure 4(c) is a graph showing the first charge-discharge curve of a lithium-ion battery with a positive electrode sheet prepared by electrodepositing lithium iron phosphate particles on carbon cloth at a rate of 0.1C.

Figure 5(a) is a scanning electron image of composite electrodeposited lithium iron phosphate and lithium lanthanum titanate (abbreviated as "LLTO") particles on carbon paper.

Figure 5(b) is the X-ray diffraction pattern of composite electrodeposited lithium iron phosphate and lithium lanthanum titanate particles on carbon paper.

Figure 5(c) is a graph showing the first charge-discharge curve of a lithium-ion battery with a cathode sheet prepared by composite electrodepositing lithium iron phosphate and lithium lanthanum titanate particles on carbon paper at a rate of 0.1C.

Figure 6(a) is an SEM image of the continuous electrodeposition of nickel-cobalt-aluminate microparticles on carbon cloth.

Figure 6(b) is the X-ray energy spectrum of nickel-cobalt-aluminate microparticles continuously electrodeposited on carbon cloth.

Figure 6(c) is a graph showing the first charge-discharge curve of a lithium-ion battery with a positive electrode sheet prepared by continuously electrodepositing nickel cobalt lithium aluminate on carbon cloth at a rate of 0.1C.

Detailed ways

The present invention will be described in detail below with reference to the specific embodiments and with reference to the

traditional process embodiments

6 and 7.

Example 1 Electrodeposition of elemental sulfur particles on carbon fiber woven cloth

First, measure 40 mL of stabilizer ethanol with a beaker, add 70 mg of nano-sulfur, and keep it in a water bath at 60°C for about 15 minutes, then pour in 30 mL of deionized water, and ultrasonically vibrate for 30 minutes to form a stable sol. Negatively charged, anodic electrophoresis needs to be performed.

The Ф12mm carbon cloth sheet is cut vertically in the middle of the electrophoresis tank and connected to the positive electrode of the DC power supply, and the carbon rod is selected as the counter electrode, which is divided into two parts and placed symmetrically on both sides of the deposited carbon paper cloth sheet. The distance is about 10mm; pour the sol into the electrophoresis tank, if the liquid level is lower than the height of the slit, directly connect the DC power supply, start the electrodeposition with a constant voltage of 90V, and start the magnetic stirrer to make the magnetic rotor in the electrophoresis tank rotate at a low speed, Suspend the particles, turn off the DC power supply and the magnetic stirrer successively after about 8 minutes; remove the Ф12mm carbon cloth sheet and let it dry naturally.

Put the sulfur-loaded Ф12mm carbon cloth sheet into the exhaust fan, and apply a wind pressure of 0.5MPa. On the one hand, the adhesion strength of the particles on the carbon cloth is detected, and on the other hand, the surface dust is absorbed to prevent contamination of the electron microscope sample chamber; The morphology observed under the electron microscope is shown in Fig. 2(a), and the X-ray energy spectrum shows the composition as shown in Fig. 2(b).

Calculate the weight gain of the carbon cloth sheet due to the electrodeposition of sulfur, and then use the carbon cloth sheet as the positive electrode to assemble the experimental battery, and input the required parameters on the automatic charging and discharging instrument to test the electrochemical performance. Figure 2(c) shows that the first discharge specific capacity at 0.1C rate is 857.7mAh·g ^-1 .

Example 2 Composite electrodeposition of elemental sulfur and neodymium oxide particles on aluminum foil

The preparation process and preparation amount of the negatively charged sol of sulfur colloidal particles are the same as in Example 1, and the amount of nano-sulfur added is still 70 mg, but since the neodymium oxide particles almost form positively charged colloidal particles in various dispersants including water and ethanol , so by adding an appropriate amount of ferric chloride containing Fe ³⁺ to the sulfur sol to make the sulfur colloidal particles positively charged, here 2.0 mg of neodymium oxide particles are added to the sulfur sol, and ultrasonic oscillation is continued for 10 minutes, so the sulfur particles can be mixed with the oxidized Neodymium particles were subjected to cathodic electrophoretic co-deposition.

The cut Ф12mm aluminum foil stands vertically in the middle of the electrophoresis tank and is connected to the negative pole of the DC power supply, and the carbon rod is selected as the opposite pole, which is divided into two parts and placed symmetrically on both sides of the deposited aluminum foil, about 10mm away from the aluminum foil. ; Pour the sol into the electrophoresis tank, if the liquid level is lower than the height of the slit, directly connect the DC power supply, start the electrodeposition with a constant voltage of 95V, and start the magnetic stirrer to make the magnetic rotor in the electrophoresis tank rotate at a low speed to suspend the particles , Turn off the DC power supply and the magnetic stirrer successively after about 10 minutes; remove the Ф12mm aluminum foil, and let it dry naturally.

The operation of detecting the adhesion strength and the anti-smearing electron microscope sample chamber is the same as that of Example 1, and the morphology and composition are shown in Fig. 3(a) and Fig. 3(b), respectively. The experimental battery was assembled with the aluminum foil as the positive electrode. Figure 3(c) shows that the first discharge specific capacity at 0.1C rate after adding neodymium oxide reaches 1034.5mAh·g ^-1 .

Example 3 Electrodeposition of lithium iron phosphate particles on carbon fiber woven cloth

First measure 1000mL of isopropanol in a beaker, add 4g of lithium iron phosphate, dropwise add hydrochloric acid to make the pH value 3.0, and ultrasonically shake for about 60 minutes to form a sol. At this time, the lithium iron phosphate gel particles are positively charged, and cathodic electrophoresis is required.

The cut Ф12mm carbon cloth sheet stands vertically in the middle of the electrophoresis tank and is connected to the negative electrode of the DC power supply, and the carbon rod is selected as the counter electrode, which is divided into two parts and placed symmetrically on both sides of the deposited carbon paper cloth sheet, which is connected with the carbon cloth sheet. The distance is about 20mm; pour the sol into the electrophoresis tank, if the liquid level is higher than the lower edge of the slit, start the liquid pump to recover the leaked electrolyte, and start the magnetic stirrer to vigorously stir the electrolyte for about 10 minutes; then Turn on the DC power supply, start the electrodeposition with a constant voltage of 100V, and reduce the rotational speed of the magnetic stirrer to make the magnetic rotor in the electrophoresis tank rotate at a low speed to suspend the particles. After about 6 minutes, turn off the DC power supply, the liquid pump and the magnetic stirring. Remove the Ф12mm carbon cloth and let it dry naturally.

The operation of detecting adhesion strength and anti-smearing electron microscope sample chamber is the same as Example 1, and the morphology and composition are shown in Fig. 4(a) and Fig. 4(b), respectively. The carbon cloth sheet was used as the positive electrode sheet to assemble the experimental battery. Figure 4(c) shows that the first discharge specific capacity at 0.1C rate is 113.7mAh·g ^-1 .

Example 4 Composite electrodeposition of lithium iron phosphate particles and lithium lanthanum titanate (abbreviated as "LLTO") particles on carbon paper

The preparation process and preparation amount of the positively charged sol of lithium iron phosphate colloidal particles are the same as in Example 3, and the addition amount of lithium iron phosphate powder is still 4g, because the lithium lanthanum titanate particles and lithium iron phosphate particles are uniform in the isopropanol dispersant. Positively charged colloidal particles can be formed. Here, 160 mg of lithium lanthanum titanate powder is added to the lithium iron thiophosphate sol, and ultrasonic oscillation is continued for 10 minutes. The lithium lanthanum titanate particles and the lithium iron phosphate particles can be co-deposited by cathodic electrophoresis.

The cut Ф12mm carbon paper is placed vertically in the middle of the electrophoresis tank and is connected to the negative electrode of the DC power supply. The carbon rod is selected as the counter electrode, and it is divided into two parts and placed symmetrically on both sides of the deposited carbon paper, at a distance from the carbon paper. About 20mm; pour the sol into the electrophoresis tank, if the liquid level is higher than the lower edge of the slit, start the liquid pump to recover the leaked electrolyte, and start the magnetic stirrer to vigorously stir the electrolyte for about 10 minutes; then connect Turn on the DC power supply, start the electrodeposition with a constant voltage of 100V, and reduce the rotational speed of the magnetic stirrer to make the magnetic rotor in the electrophoresis tank rotate at a low speed to suspend the particles. After about 6 minutes, turn off the DC power supply, the liquid pump and the magnetic stirrer successively. ;Remove the Ф12mm carbon paper and let it dry naturally.

The operation of detecting the adhesion strength and anti-fouling electron microscope sample chamber is the same as Example 3. The morphology and composition are shown in Fig. 5(a) and Fig. 5(b), respectively. Due to the thick deposition layer, it cannot be displayed on the X-ray diffraction pattern. Diffraction peaks of carbon. The carbon cloth sheet was used as the positive electrode sheet to assemble the experimental battery. Figure 5(c) shows that the first discharge specific capacity at 0.1C rate is 131.0mAh·g ^-1 .

Example 5 Continuous electrodeposition of nickel cobalt lithium aluminate ternary material particles on carbon fiber woven cloth

Weigh the isopropanol dispersion and the nickel-cobalt-aluminate lithium powder respectively, so that the mass percentage of the latter is 1.5%, add hydrochloric acid dropwise to make the pH value 3.0, and ultrasonically oscillate for about 60 minutes to form a sol. At this time, the nickel-cobalt aluminate lithium The colloidal particles are positively charged and require cathodic electrophoresis.

Make the carbon cloth stand vertically in the middle of the electrophoresis tank, connect it with the negative pole of the DC power supply, and select the carbon rod as the counter electrode, which is divided into two parts and placed symmetrically on both sides of the deposited carbon cloth, about 20mm away from the carbon cloth. ; Pour the sol into the electrophoresis tank, submerge the carbon felt, start the liquid pump to recover the leaked electrolyte, and start the magnetic stirrer to vigorously stir the electrolyte for about 10 minutes; through the transmission device, the carbon cloth passes through the slit at a constant speed Pass through the electrophoresis tank, then turn on the DC power supply, use a constant voltage of 100V to start electrodeposition, and reduce the rotational speed of the magnetic stirrer to make the magnetic rotor in the electrophoresis tank rotate at a low speed to suspend the particles; the emission beam passes through the dispersion liquid and irradiates the photoelectron On the excitation board, the control circuit enables the clutch of the magnetostrictive cone plug and the funnel to automatically add active material; when the carbon cloth reaches the required active material load, the DC power supply, automatic feeding control circuit, carbon cloth transmission device, Liquid pump and magnetic stirrer; remove carbon cloth and dry.

The operation of detecting adhesion strength and anti-smearing electron microscope sample chamber is the same as Example 3. The morphology and composition are shown in Figure 6(a) and Figure 6(b), respectively. The carbon cloth sheet is used as the positive electrode sheet to assemble the experimental battery, as shown in Figure 6( c) shows that the first discharge specific capacity at 0.1C rate is 155.0mAh·g ^-1 .

Example 6 Preparation of lithium-sulfur battery electrode sheet by compounding mixture on aluminum foil

The active material elemental sulfur, the conductive agent acetylene black, and the binder LA132 with a concentration of 16% are prepared in a mass ratio of 82:15:3, add an appropriate amount of solvent deionized water, stir for 6 hours, and mix into a slurry with suitable viscosity; The material is coated on one side of the aluminum foil, initially scraped with a scraper to make the thickness about 100μm, dried and wound in an oven, and then coated with the slurry on the other side of the aluminum foil, scraped and dried; rolled with a roller, The total thickness is 120 μm, and the positive electrode plate of lithium-sulfur battery is prepared.

Example 7 Composite mixture on aluminum foil to prepare lithium ion battery electrode sheet

The active material lithium cobaltate, the conductive agent acetylene black, and the binder PVDF are batched in a mass ratio of 8:1:1, and an appropriate amount of solvent NMP is added, stirred for 6 hours, and mixed into a slurry with suitable viscosity; the slurry is coated on aluminum foil. On one side, use a scraper to initially flatten it to make the thickness of about 150μm, dry and roll it in an oven, and then coat the slurry on the other side of the aluminum foil, scrape and dry it; roll it with a roller to make the total thickness 220μm , to prepare the positive pole piece of lithium ion battery.

It should be understood that, for those skilled in the art, improvements or changes can be made according to the above description, and all these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims

A device for electrodepositing material on an electrode current collector of a lithium ion battery, characterized in that it comprises an electrophoresis tank (2), the electrophoresis tank (2) contains an electrolyte, and solid particles to be deposited and the electrolyte form a sol The solid particles to be deposited are a mixture of a substance or a plurality of substances; the conductive sheet (5) to be deposited stands vertically in the middle of the electrophoresis tank (2), and is connected to the positive or negative electrode of the DC power supply (10), and the counter electrode (1) It is divided into two parts symmetrically distributed on both sides of the deposited conductive sheet (5); the deposited conductive sheet (5) is a flexible conductive sheet or a non-flexible conductive sheet; the solid particles dispersed in the electrolyte are separated by electrophoresis Electrodeposition to both sides of the deposited conductive sheet (5).
The device according to claim 1, wherein if the solid particles of different substances to be deposited form colloidal particles with different electrical properties in the same dispersion liquid, it is necessary to selectively add electrolytes, stabilizers or surfactants to separate the different solid particles. The electric colloidal particles are changed to be both positive or negative, and then cathodic electrophoresis or anodic electrophoresis is performed to realize the co-deposition of various solid particles, and to improve the stability of the colloid and enhance the contact between the particles and the deposited conductive sheet (5). Cohesion; if the solid particles of different substances to be deposited form colloidal particles with the same electrical properties in the same dispersion, co-deposition can be achieved without any special treatment.
The device according to claim 1, characterized in that slits (9) are opened on the two side walls of the electrophoresis tank (2), and a normally closed soft one-way valve is arranged on the slits (9). ; Driven by the transmission device, the deposited conductive sheet (5) enters the electrophoresis tank (2) from one side slit, and exits the electrophoresis tank (2) from the other side slit. During the electrophoresis process, the deposited conductive sheet (5) in motion.
The device according to claim 1, characterized in that, the deposited conductive sheet (5) is a high-conductivity flexible loose material.
The device according to any one of claims 1-4, further comprising an automatic feeding system, comprising an incident light glass window (11), an outgoing light glass window (12), an optoelectronic excitation plate (13), and an optoelectronic receiving plate (14), a cone plug (16), a funnel (17); the cone plug (16) is made of ferromagnetic, and the cone plug (16) is wound with a coil; the lower part of the funnel (17) is provided with a The cone-shaped feeding hole is matched with the top of the cone, and the funnel (17) is made of magnetic material; an incident light glass window (11) is arranged on one side wall of the electrophoresis tank (2), and an outgoing light glass window is arranged on the opposite side wall (12), the light beam passes through the incident light glass window (11) and the outgoing light glass window (12) through the dispersion liquid, and then shoots on the photoelectron excitation plate (13). When the electrodeposition proceeds, the concentration of the particles in the electrolyte When the light beam is lowered so as to reduce the scattering of the light beam, the light beam with sufficient intensity will excite the photoelectrons on the photoelectron excitation plate (13) and hit the photoelectron receiving plate (14), so that the automatic feeding control circuit is turned on to make the cone plug (16) When the coil is energized, the cone plug (16) generates a magnetic field and repels the magnetic funnel (17) with the same magnetic polarity as the cone plug (16). The concentration of particles in the electrolyte increases, and the scattering of the light beam increases, so that the intensity of the light beam is not enough to excite photoelectrons on the photoelectron excitation plate (13), the automatic feeding control circuit is disconnected, and the cone plug (16) is demagnetized and blocked. The feeding port of the funnel (17) automatically stops feeding.
The device according to any one of claims 1-4, further comprising an automatic feeding system, comprising an incident light glass window (11), an outgoing light glass window (12), an optoelectronic excitation plate (13), and an optoelectronic receiving plate (14), a cone plug (16), a funnel (17); the cone plug (16) is made of a magnetostrictive material; an incident light glass window (11) is arranged on one side wall of the electrophoresis tank (2), and the other opposite A light exit glass window (12) is arranged on one side wall, and the light beam passes through the incident light glass window (11) and the exit light glass window (12), passes through the dispersion liquid, and strikes the photoelectron excitation plate (13). When the concentration of the particles in the electrolyte decreases and the scattering of the light beam is reduced, the light beam with sufficient intensity will excite the photoelectrons on the photoelectron excitation plate (13), hit the photoelectron receiving plate (14), and the automatic feeding control circuit Turn on, so that the size of the cone plug (16) made of magnetostrictive material wound around the coil changes in the length direction, and there is a gap between the funnel (17) containing the active material powder (18) above, and the active material powder (18) will be added to the electrolyte, so that the concentration of particles in the electrolyte increases, the scattering of the beam increases, and the intensity of the beam is reduced to be insufficient to excite the photoelectrons on the photoelectron excitation plate (13), and the automatic feeding control circuit When the circuit is disconnected, the size of the cone plug (16) made of magnetostrictive material is restored to its original shape, and the feeding port of the funnel (17) is blocked to automatically stop feeding.
A method for electrodepositing materials on an electrode current collector of a lithium ion battery, characterized in that it comprises the following steps: Step A1, an electrophoresis tank (2) is filled with an electrolyte, and the solid particles to be deposited and the electrolyte form a sol; The solid particles to be deposited are a mixture of a substance or a plurality of substances; in step A2, the conductive sheet (5) to be deposited is vertically erected in the middle of the electrophoresis tank (2) and connected to the positive or negative electrode of the DC power supply (10); Step A3, the counter electrode (1) is divided into two parts and symmetrically distributed on both sides of the deposited conductive sheet (5); the deposited conductive sheet (5) is a flexible conductive sheet or a non-flexible conductive sheet; Step A4, open the electrophoresis The cell power supply uses electrophoresis to electrodeposit solid particles dispersed in the electrolyte on both sides of the deposited conductive sheet (5).
The method according to claim 7, wherein, in step A1, if the solid particles to be deposited are solid particles of different substances, and different solid particles form colloidal particles with different electrical properties in the same dispersion liquid, it is necessary to pass Choose to add electrolytes or surfactants to change the colloidal particles with different electric properties to the same positive charge or the same negative charge.
The method according to claim 7, characterized in that it further comprises step A5, automatic feeding; an incident light glass window (11) is arranged on one side wall of the electrophoresis tank (2), and an outgoing light is arranged on the opposite side wall of the electrophoresis tank (2). The glass window (12), the light beam passes through the incident light glass window (11) and the outgoing light glass window (12), passes through the dispersion liquid, and is emitted to the photoelectron excitation plate (13). When the concentration of the ions decreases and the scattering of the light beam is reduced, the light beam with sufficient intensity will excite the photoelectrons on the photoelectron excitation plate (13) and hit the photoelectron receiving plate (14), so that the automatic feeding control circuit is turned on for feeding and feeding. After the concentration of the particles in the electrolyte increases, the scattering of the light beam increases, so that the intensity of the light beam is reduced to be insufficient to excite photoelectrons on the photoelectron excitation plate (13), and the automatic feeding control circuit is disconnected.
A method for making a positive electrode sheet or a negative electrode sheet of a lithium ion battery, characterized in that, the electrode current collector of a lithium ion battery is prepared according to any one of the methods of claims 7-9, and the deposited conductive sheet (5) is a high-conductivity flexible loose material , The positive electrode sheet or the negative electrode sheet is made based on the electrode current collector, which saves the rolling process in the traditional electrode manufacturing process, and does not need to add conductive agents and binders, which simplifies the production process.