Electrode slurry and defoaming method thereof, computer readable storage medium, pulping equipment and battery

Abstract

The invention provides electrode slurry and a defoaming method thereof, a computer readable storage medium, slurry preparation equipment and a battery. The defoaming method of the electrode slurry comprises the following steps: acquiring the electrode slurry; the electrode slurry is subjected to defoaming operation, and the defoaming operation on the electrode slurry specifically comprises the following steps that under the vacuum degree P1, the electrode slurry is subjected to primary defoaming treatment; carrying out secondary defoaming treatment on the electrode slurry subjected to the primary defoaming treatment under the vacuum degree P2; wherein P1 is less than 0, P2 is less than 0, and P1 is less than P2. According to the defoaming method of the electrode slurry, the removal efficiency of the bubbles of the electrode slurry is relatively high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to an electrode slurry, a defoaming method thereof, a computer readable storage medium, a slurry preparation device and a battery. BACKGROUND

[0002] The bubbles in the electrode slurry that are not effectively removed are prone to break in the process of drying the pole piece, and then form air pits or even pinholes on the pole piece, which greatly affects the electrochemical performance of the battery. For example, the patent application with the application number CN202010869655.8 stirs at a high speed under vacuum and then at a low speed to remove the bubbles in the electrode slurry, but the total removal time of the bubbles is long and the efficiency is low, especially for the electrode slurry with a large surface area of the conductive agent and an alkaline active material, the amount of small bubbles generated is large and difficult to remove. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide an electrode slurry and a defoaming method thereof, a computer readable storage medium, a slurry preparation device and a battery, which have good bubble removal effect and high removal efficiency for the electrode slurry.

[0004] A defoaming method of an electrode slurry, comprising the following steps:

[0005] Obtaining an electrode slurry;

[0006] Defoaming the electrode slurry, wherein the defoaming operation of the electrode slurry is as follows:

[0007] Defoaming the electrode slurry once at a P1 vacuum degree;

[0008] Defoaming the electrode slurry twice at a P2 vacuum degree after the first defoaming treatment;

[0009] Wherein, P1<0, P2<0, P1<P2.

[0010] An electrode slurry comprising an active material, a binder, a solvent and a conductive agent, wherein the active material, the binder, the solvent and the conductive agent are mixed and then treated by the defoaming method of the electrode slurry according to any one of the above embodiments, and the solvent is removed after the electrode slurry is dried.

[0011] A computer readable storage medium based on slurry defoaming, which stores a computer program or instructions, when the computer program or instructions are executed by a computing device, the defoaming method of the electrode slurry according to any one of the above embodiments is implemented.

[0012] A slurry preparation device for preparing an electrode slurry for performing the method of preparing the slurry according to any one of the above embodiments.

[0013] A battery comprising at least an electrode sheet and an electrolyte, the electrolyte being in contact with the electrode sheet, at least one side of the electrode sheet being coated with the electrode slurry according to any one of the above embodiments.

[0014] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The negative electrode slurry prepared using the electrode slurry of Example 2 for Group a5 and the negative electrode sheet obtained after coating and drying;

[0016] Figure 2 The negative electrode sheet obtained after coating and drying of the negative electrode slurry prepared using the electrode slurry of Comparative Example 1 for Group a5. DETAILED DESCRIPTION

[0017] In order to facilitate the understanding of the present application, a more complete understanding of the present application can be had by reference to the following description and the accompanying drawings. The figures in the drawings give a preferred embodiment of the present application. However, the present application can be realized in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It is therefore an object of the present application to provide a slurry preparation device for preparing an electrode slurry for performing the method of preparing the slurry according to any one of the above embodiments.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0019] The present application provides a defoaming method of electrode slurry. In order to better understand the defoaming method of electrode slurry of the present application, the defoaming method of electrode slurry of the present application is further explained as follows:

[0020] The defoaming method of electrode slurry of an embodiment includes all or part of the following steps:

[0021] S100, obtaining an electrode slurry. It can be understood that the electrode slurry is a positive electrode slurry or a negative electrode slurry of a battery, and the electrode slurry in this step is an electrode slurry obtained after being uniformly mixed, i.e., an electrode slurry obtained after each component in the electrode slurry is fully mixed and uniformly mixed by a conventional electrode slurry mixing operation.

[0022] S200, defoaming operation is performed on the electrode slurry, wherein the defoaming operation is performed on the electrode slurry, and the specific operation is as follows:

[0023] The electrode slurry is subjected to a first defoaming treatment under a P1 vacuum degree;

[0024] The electrode slurry after the first defoaming treatment is subjected to a second defoaming treatment under a P2 vacuum degree;

[0025] Wherein, P1 < 0, P2 < 0, and P1 < P2. It can be understood that the micro-bubbles are difficult to break or merge, so that the vacuum degree is first increased and then decreased after the defoaming under the P1 vacuum degree and then the defoaming under the P2 vacuum degree, so as to achieve the effect of bubble expansion and contraction, promote the merging of the bubbles, and then realize the gradual increase of the particle size of the bubbles. When the bubble breaking point is reached after the sudden change of the vacuum degree, the bubble is broken and removed, further effectively removing the bubbles and improving the removal efficiency of the bubbles.

[0026] The defoaming method of the electrode slurry described above makes the vacuum degree first increase and then decrease after the defoaming under the P1 vacuum degree and then the defoaming under the P2 vacuum degree, so as to achieve the effect of bubble expansion and contraction, promote the merging of the bubbles, and then realize the gradual increase of the particle size of the bubbles. When the bubble breaking point is reached after the sudden change of the vacuum degree, the bubble is broken and removed, further effectively removing the bubbles and improving the removal efficiency of the bubbles.

[0027] It can be understood that the bubble removal of the positive electrode slurry or the negative electrode slurry is mostly realized by vacuum extraction, and the smaller the vacuum degree value, the better the defoaming effect. However, for micro-bubbles, the vacuum degree value is small, although the defoaming effect can be improved, but it is easy to reach a balance state, that is, the vacuum degree value is smaller, but the bubble removal effect cannot be further improved, and the bubbles cannot be further effectively removed and the removal efficiency of the bubbles cannot be improved. Therefore, in the present case, the vacuum degree value is first decreased and then increased, so as to achieve the effect of bubble expansion and contraction, promote the merging of the bubbles, and then realize the gradual increase of the particle size of the bubbles. When the bubble breaking point is reached after the sudden change of the vacuum degree, the bubble is broken and removed, improving the bubble removal effect of the electrode slurry and improving the removal efficiency of the bubbles.

[0028] In one embodiment, the transition between P1 and P2 is a gradient change. Further, the vacuum degree change rate is -1 kpa / s to -9 kpa / s. Further, the electrode slurry is subjected to a first defoaming treatment at a vacuum degree change rate of -1 kpa / s to -9 kpa / s to P1. Further, the electrode slurry after the first defoaming treatment is subjected to a second defoaming treatment at a vacuum degree change rate of -1 kpa / s to -9 kpa / s to P2. It can be understood that the transition between P1 and P2 is a gradient change, that is, the vacuum degree is increased to P1 at a gradient from atmospheric pressure or the vacuum degree of the previous operation process, and then the vacuum degree is decreased to P2 at a gradient from P1, and the vacuum degree change rate is -1 kpa / s to -9 kpa / s, achieving the effect that the bubbles expand and contract like breathing, further promoting the merging of bubbles, and then realizing the gradual increase of the particle size of the bubbles, achieving further effective removal of the bubbles and improving the removal efficiency of the bubbles.

[0029] In one embodiment, P1 is selected from -90 kpa to -110 kpa. Further, P2 is selected from -40 kpa to -60 kpa. Further, the electrode slurry is subjected to the defoaming operation for ≥20 times. Further, the electrode slurry is subjected to the defoaming operation for 20 to 40 times, preferably ensuring the removal effect and efficiency of the bubbles of the electrode slurry.

[0030] In one embodiment, the electrode slurry is subjected to the defoaming operation under stirring. Further, the electrode slurry is subjected to the defoaming operation at a temperature of 20 to 35°C. Further, the electrode slurry is subjected to the defoaming operation for 15 to 60 minutes.

[0031] The present application also provides a computer readable storage medium based on slurry defoaming. Further, the computer readable storage medium based on slurry defoaming stores a computer program or instructions, which, when executed by a computing device, implements the electrode slurry defoaming method of any of the above embodiments. Further, the electrode slurry defoaming method comprises the following steps: obtaining an electrode slurry; and defoaming the electrode slurry, wherein the defoaming of the electrode slurry is performed as follows: subjecting the electrode slurry to a first defoaming treatment at a P1 vacuum degree; and subjecting the electrode slurry after the first defoaming treatment to a second defoaming treatment at a P2 vacuum degree; wherein P1 < 0, P2 < 0, and P1 < P2.

[0032] The present application also provides a slurry preparation device for preparing the electrode slurry. Further, the slurry preparation device is used to perform the slurry preparation method of any of the above embodiments. Further, the defoaming method of the electrode slurry comprises the following steps: obtaining the electrode slurry; and defoaming the electrode slurry, wherein the defoaming of the electrode slurry is performed as follows: performing a first defoaming treatment on the electrode slurry at a P1 vacuum degree; and performing a second defoaming treatment on the electrode slurry after the first defoaming treatment at a P2 vacuum degree; wherein P1 < 0, P2 < 0, and P1 < P2.

[0033] The present application also provides an electrode slurry comprising an active material, a binder, a solvent, and a conductive agent. Further, the active material, the binder, the solvent, and the conductive agent are mixed and then treated by the defoaming method of the electrode slurry of any of the above embodiments, and the solvent is removed after the electrode slurry is dried.

[0034] It can be understood that the electrode slurry is a positive electrode slurry or a negative electrode slurry, and for the electrode slurry with a relatively small or relatively large specific surface area, after the components of the electrode slurry are uniformly mixed, the defoaming method of the electrode slurry of any of the above embodiments is used for treatment, which greatly improves the defoaming efficiency of the electrode slurry while ensuring good defoaming effect, especially for the electrode slurry with a relatively large specific surface area and strong surface activity, and the particle size of each material in the electrode slurry is mostly nanoscale, which causes the generation of many tiny bubbles, i.e., bubbles with a particle size less than 100 μm, during the sufficient mixing of the components of the electrode slurry, increasing the difficulty of removal. After the defoaming method of the electrode slurry of any of the above embodiments is used for treatment, the removal efficiency of the bubbles in the electrode slurry is ensured, and the removal effect of the electrode slurry is effectively improved, thereby better ensuring the electrochemical performance of the battery.

[0035] In one embodiment, the conductive agent includes a conductive spherical node material, a conductive fiber transition material, and a conductive tubular conductive material. Further, the conductive spherical node material is at least one of carbon black (SP), furnace black (AB), acetylene black (AC), and ketjen black (KB). Further, the conductive fiber transition material is carbon fiber (VGCF). Further, the conductive tubular conductive material is single-walled carbon nanotube (SWCNT) and / or few-walled carbon nanotube (FWCNT). It can be understood that the conductive spherical node material, the conductive fiber transition material, and the conductive tubular conductive material are used in combination to form a network three-dimensional structure, that is, to form a large number of open pores and through channels, thereby effectively improving the rapid conduction of electrons and the deintercalation capacity of lithium ions of the electrode slurry, and also increasing the specific surface area of the electrode slurry. When the conductive agent with a large specific surface area is added to the positive electrode slurry or the negative electrode slurry, especially when the conductive tubular conductive material of the conductive agent is SWCNT and / or FWCNT, the specific surface area of the electrode slurry will be significantly increased, and the surface activity will be stronger. In addition, the particle sizes of the various substances in the electrode slurry are mostly in the nanometer range, so that when the various components of the electrode slurry are fully mixed, a large number of micro-bubbles, that is, bubbles with a particle size of less than 100 μm, are generated, and the removal difficulty is greatly increased. However, when the electrode slurry of any one of the above embodiments is treated by the defoaming method, the vacuum degree is first increased and then decreased after defoaming at P1 vacuum degree and then at P2 vacuum degree, so that the micro-bubbles are inflated and then contracted, the bubbles are merged, and the particle size of the bubbles is gradually increased. Then, the bubbles are broken and removed at the breaking point of the bubbles after the sudden change of the vacuum degree, and the micro-bubbles are effectively and fully removed.

[0036] In one embodiment, the conductive agent is composed of a conductive spherical node material, a conductive fiber transition material, and a conductive tubular conductive material. It can be understood that in this embodiment, the conductive agent only contains the conductive spherical node material, the conductive fiber transition material, and the conductive tubular conductive material, and the conductive spherical node material is at least one of carbon black, furnace black, acetylene black, and ketjen black; the conductive fiber transition material is carbon fiber; and the conductive tubular conductive material is single-walled carbon nanotube and / or few-walled carbon nanotube, without containing other components.

[0037] The conductive agent is compounded by the conductive spherical node material, the conductive fiber transition material and the conductive tubular conductive material, the conductive tubular conductive material has good electron conduction capacity, which can accelerate the conduction speed of electrons, the conductive spherical node material increases the distribution density of the conductive agent, provides more electron conduction contact points for lithium ions in the electrode slurry, the conductive fiber transition material is relatively hard, which better connects the conductive tubular conductive material and the conductive spherical node material as a skeleton, forms a three-dimensional network structure, realizes the rapid conduction of electrons in the electrode slurry, improves the de-intercalation capacity of lithium ions embedded in the electrode slurry, and effectively improves the conductive performance of the electrode slurry; further, the conductive tubular conductive material, the conductive fiber transition material and the conductive tubular conductive material form a point-line-surface three-dimensional network structure. The point-line-surface three-dimensional network structure is that the conductive tubular conductive material is distributed as a surface, and the conductive fiber transition material enters between the conductive tubular conductive material to strengthen the skeleton connection rigidity of the three-dimensional network structure, forming a porous structure, and the conductive spherical node material enters the skeleton of the three-dimensional network structure to fill, so as to improve the distribution density of the conductive agent, and the electrode slurry has good conductivity.

[0038] In one of the embodiments, the active material is a positive active material or a negative active material. Further, the active material is at least one of silicon-carbon negative material, silicon-oxygen negative material, silicon-based negative material, graphite and hard carbon. Further, the binder in the negative electrode slurry is at least one of carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), polyimide (PI) and polyacrylic acid (PAA). Further, the positive active material is at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium nickel manganese oxide, lithium nickel oxide and lithium-rich manganese-based positive material. Further, the binder in the positive electrode slurry is at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and PAA. Further, the active material is silicon-carbon negative material and / or silicon-oxygen negative material. It can be understood that when the active material in the electrode slurry is silicon-carbon negative material and / or silicon-oxygen negative material, the electrode slurry is made alkaline, and the particle size of each material in the electrode slurry is mostly nanoscale, which makes it easy to produce tiny bubbles during the uniform mixing of the electrode slurry. In combination with the defoaming method of the electrode slurry of any one of the above embodiments, the defoaming is carried out under P1 vacuum degree and then under P2 vacuum degree, so that the vacuum degree first increases and then decreases, achieving the effect of tiny bubble expansion and contraction, promoting the merging of bubbles, and then realizing the gradual increase of the particle size of the bubbles. Then, the bubbles are removed when the vacuum degree breaks through the change point, effectively realizing the full and effective removal of tiny bubbles. Further, the solvent is water or N-methyl pyrrolidone (NMP). Further, in one of the embodiments, the electrode slurry at least includes silicon-carbon negative material and / or silicon-oxygen negative material. Further, in another embodiment, the electrode slurry at least includes one conductive agent with a specific surface area ≥200m 2 / g.

[0039] In one of the embodiments, the specific surface area of the conductive agent is ≥200m 2 / g. Further, when the conductive agent contains multiple types of conductive agents, the specific surface area of at least one type of conductive agent is ≥200m 2 / g. Further, the total content of the conductive agent in the electrode slurry is 0.5% to 4%. It can be understood that the specific surface area of the conductive agent is ≥200m 2when the total content of the conductive agent in the electrode slurry is 0.5% to 4%, even if the micro-bubbles are easily generated when the components of the electrode slurry are uniformly mixed, the electrode slurry is treated by using the defoaming method of the electrode slurry of any one of the above embodiments, and defoaming is performed under P1 vacuum degree and then under P2 vacuum degree, so that the vacuum degree is first increased and then decreased, the effect of expansion and contraction of the micro-bubbles is achieved, the merging of the bubbles is promoted, and then the gradual increase of the particle size of the bubbles is achieved, and then the bubbles are removed by breaking at the breaking point of the bubbles after the sudden change of the vacuum degree, so that the micro-bubbles are effectively removed.

[0040] In one of the embodiments, when the electrode slurry is the positive electrode slurry, the mass ratio of the components in the electrode slurry is positive electrode active material: SP: VGCF: SWCNT: PVDF: NMP = 96.4%: 1.5%: 0.5%: 0.1%: 1.5%: (35% to 50%). Further, when the electrode slurry is the negative electrode slurry, the mass ratio of the components in the electrode slurry is negative electrode active material: SP: VGCF: SWCNT: CMC: SBR: H2O = 94.95%: 1.5%: 0.5%: 0.05%: 1.5%: 1.5%: (110% to 130%). Further, when the electrode slurry is the negative electrode slurry, the mass ratio of the components in the electrode slurry is negative electrode active material: SP: VGCF: SWCNT: CMC: PAA: H2O = 95.45%: 1.5%: 0.5%: 0.05%: 0.5%: 2.0%: (110% to 130%).

[0041] The application also provides a battery comprising at least an electrode sheet and an electrolyte, the electrolyte being in contact with the electrode sheet, at least one side of the electrode sheet being coated with the electrode paste of any one of the above embodiments. It can be understood that the electrode paste is obtained by the defoaming method of the electrode paste of any one of the above embodiments, effectively ensuring the effective removal of bubbles in the electrode paste, thereby effectively reducing the formation of pits or pinholes after the electrode paste coated on the electrode sheet is dried, and better ensuring the electrochemical performance of the battery. Further, the active material in the electrode paste is a silicon-based negative material and graphite. Further, the mass ratio of the silicon-based material and graphite is 100:(0-534). Further, the mass ratio of the silicon-based material and graphite is 100:(1-534). Further, the mass ratio of the silicon-based material and graphite is 100:(100-500). It can be understood that in the battery, the electrode paste contains a silicon-based material, which expands by up to 300% when intercalating lithium, making it easy to crack and powder during formation. Therefore, in the present application, in order to prevent cracking and powdering of the battery, the battery is formed by the formation method of the battery. In order to better understand the formation method of the battery of the present application, the formation method of the battery of the present application is further explained as follows: the formation method of the battery of one embodiment comprises the following steps: S010, obtaining a battery to be formed. It can be understood that the battery to be formed comprises at least an electrode sheet and an electrolyte, the electrolyte being in contact with the electrode sheet, i.e. the negative electrode sheet is in contact with the electrolyte, better ensuring the effect of the electrolyte as an ion transport medium. Further, at least one side of the electrode sheet is coated with the electrode paste of any one of the above embodiments. Further, the electrode paste is obtained by the defoaming method of the electrode paste. Further, the electrode sheet is a negative electrode sheet, the active material in the electrode paste coated on at least one side of the negative electrode sheet is a silicon-based material and graphite, the silicon-based material comprises at least one of silicon-carbon negative material, silicon-oxygen negative material and silicon-based negative material, and the mass ratio of the silicon-based material and graphite is 100:(0-534). Further, the particle size D50 of the silicon-based material is ≤10 nm. Further, the silicon content in the silicon-based material is 10%-100%; S020, performing a pressure and heating formation operation on the battery to be formed, wherein the pressure and heating formation operation on the battery to be formed comprises the following operation steps: pre-expanding and standing treatment of the battery to be formed at a pressure F1; swelling and charging treatment of the pre-expanded and standing treated battery to be formed at a pressure F2; liquid absorption and slow swelling standing treatment of the swelling and charging treated battery to be formed at a pressure F3; wherein F1=F2, and F3F1.

[0042] The formation method of the battery makes the negative plate contact with the electrolyte, preferably ensures the effect of the electrolyte as an ion transmission medium, and the electrode slurry has a high energy density. The pressurized and heated formation operation of the battery to be formed is combined to effectively reduce the powdering and cracking of the layer structure formed by the electrode slurry on the basis of ensuring the energy density of the battery, reduce the uneven distribution of the electrolyte caused by extrusion, improve the density and uniformity of the SEI film, and further preferably improve the electrochemical performance of the battery.

[0043] In one embodiment, the pressurized and heated formation operation of the battery to be formed is carried out at a temperature of 35°C to 80°C. Further, the swelling suppression charging treatment of the battery to be formed after the pre-swelling standing treatment is carried out at a current of 0.01C to 0.5C. Further, the pre-swelling standing treatment of the battery to be formed is carried out at a pressure of F1, and the standing time is 5 minutes to 3 hours. Further, the swelling suppression charging treatment of the battery to be formed after the pre-swelling standing treatment is carried out at a pressure of F2, and the charging time is 0.5 hours to 10 hours. Further, the liquid absorption and swelling suppression standing treatment of the battery to be formed after the swelling suppression charging treatment is carried out at a pressure of F3, and the standing time is 5 minutes to 3 hours. Further, the number of repetitions of the pressurized and heated formation operation of the battery to be formed is 2 to 7 times. Further, the number of repetitions of the pressurized and heated formation operation of the battery to be formed is 4 times. Further, in each step of the pressurized and heated formation operation of the battery to be formed, F1, F2, and F3 are independently selected, that is, F1 in any step can be the same as or different from F1 in the remaining repeated steps; similarly, F2 in any step can be the same as or different from F2 in the remaining repeated steps; similarly, F3 in any step can be the same as or different from F3 in the remaining repeated steps. Further, in each step of the pressurized and heated formation operation of the battery to be formed, the current and the temperature are independently selected, that is, in each step of the pressurized and heated formation operation of the battery to be formed, the temperature in any step can be the same as or different from the temperature in the remaining repeated steps; similarly, the current in any step can be the same as or different from the current in the remaining repeated steps. Further, F1 and F2 are each independently selected from 2 kgf / cm2 to 10 kgf / cm2. Further, F3 is selected from 0.5 kgf / cm2 to 5 kgf / cm2. Further, F1 and F2 are each independently selected from 4 kgf / cm2 to 10 kgf / cm2.

[0044] In one of the embodiments, before the step of performing the pressurized and heated formation operation on the battery to be formed, and after the step of obtaining the battery to be formed, the battery formation method further comprises the following step: performing a pre-pressurized and heated formation operation on the battery to be formed, wherein the pre-pressurized and heated formation operation on the battery to be formed comprises the following operation steps: pre-swelling and standing pre-treatment of the battery to be formed at a pressure of F4; swelling and charging pre-treatment of the battery to be formed after the pre-swelling and standing pre-treatment at a pressure of F5; and liquid absorption and swelling standing pre-treatment of the battery to be formed after the swelling and charging pre-treatment at a pressure of F6; wherein F4=F5, F6≤F4, and F4

[0045] The following examples are provided to illustrate some specific embodiments. If % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible cases, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0046] Example 1

[0047] Preparation of electrode slurry:

[0048] Preparation: the ingredients of the electrode slurry of each group according to Table 1 were prepared;

[0049] The ingredients of the electrode slurry were mixed at a stirring speed of 1500-2100 r / min, and the total stirring time was 5 h (the stirring speed was a change in the mixing speed of the conventional electrode slurry, which will not be discussed here and below);

[0050] Vacuumizing at 5rpm to control the vacuum degree to decrease to -90kpa at the speed gradient of -1kpa / s, then filling gas to control the vacuum degree to increase to -40kpa at the speed gradient of -1kpa / s, repeating this step for 30 times, the positive electrode slurry viscosity is controlled to 7000mpa.s / the negative electrode slurry viscosity is controlled to 2500mpa.s.

[0051] Example 2

[0052] Preparation of electrode slurry:

[0053] Preparation: the ingredients of the electrode slurry of each group shown in Table 1 are prepared;

[0054] Mixing the ingredients of the electrode slurry, the stirring speed is 1500-2100r / min, the total stirring time is 5h;

[0055] Vacuumizing at 5rpm to control the vacuum degree to decrease to -90kpa at the speed gradient of -1kpa / s, then filling gas to control the vacuum degree to increase to -40kpa at the speed gradient of -1kpa / s, repeating this step for 30 times, the positive electrode slurry viscosity is controlled to 7000mpa.s / the negative electrode slurry viscosity is controlled to 2500mpa.s.

[0056] Example 3

[0057] Preparation of electrode slurry:

[0058] Preparation: the ingredients of the electrode slurry of each group shown in Table 1 are prepared;

[0059] Mixing the ingredients of the electrode slurry, the stirring speed is 1500-2100r / min, the total stirring time is 5h;

[0060] Vacuumizing at 5rpm to control the vacuum degree to decrease to -90kpa at the speed gradient of -1kpa / s, then filling gas to control the vacuum degree to increase to -40kpa at the speed gradient of -1kpa / s, repeating this step for 30 times, the positive electrode slurry viscosity is controlled to 7000mpa.s / the negative electrode slurry viscosity is controlled to 2500mpa.s.

[0061] Example 4

[0062] Preparation of electrode slurry:

[0063] Preparation: the ingredients of the electrode slurry of each group shown in Table 1 are prepared;

[0064] Mixing the ingredients of the electrode slurry, the stirring speed is 1500-2100r / min, the total stirring time is 5h;

[0065] The vacuum was applied at a stirring speed of 5 rpm to control the vacuum degree to decrease at a speed gradient of -5 kpa / s to -110 kpa, and then the gas was filled to control the vacuum degree to increase at a speed of -5 kpa / s to -60 kpa. This step was repeated 20 times, and the positive electrode slurry viscosity was controlled to 7000 mpa.s and the negative electrode slurry viscosity was controlled to 2500 mpa.s.

[0066] Comparative Example 1

[0067] Preparation of the electrode slurry:

[0068] Preparation: The components of the electrode slurry of each group shown in Table 2 were prepared;

[0069] The components of the electrode slurry were mixed at a stirring speed of 1500-2100 r / min for a total stirring time of 5 h, and then vacuum was applied at a stirring speed of 5 rpm to -90 kpa for 60 min. The positive electrode slurry viscosity was controlled to 7000 mpa.s and the negative electrode slurry viscosity was controlled to 2500 mpa.s.

[0070] Table 1: Components of the electrode slurry

[0071]

[0072]

[0073] The surface observation results of the electrode slurry obtained for Examples 1 to 4, and the electrode sheet obtained after coating and drying are shown in Table 3:

[0074] Table 3:

[0075]

[0076] Figure 1 The negative electrode slurry obtained using the electrode slurry preparation of Example 2 for Group a5, and the electrode sheet obtained after coating and drying, a1 is the state of the negative electrode slurry after mixing, a2 is the state of the negative electrode slurry after vacuum degassing, a3-a4 are the states of the negative electrode slurry coated on the foil, a5 is the state of the negative electrode sheet after drying, and 36 is the state of the negative electrode sheet before rolling under a digital microscope; Figure 2The negative electrode slurry prepared by using the electrode slurry of Comparative Example 1 for Group A5 is coated and dried to obtain the corresponding electrode sheet, a1 is the state of the dried negative electrode sheet, and a2 is the partial magnified state of the digital microscope before the negative electrode sheet is rolled, and it can be seen from Table 3 that the electrode slurries of Examples 1 to 4 are all free of bubbles, and after coating and drying, the corresponding electrode sheet coating has no pits, and especially under 4.5 times magnification, the coating appearance surface is smooth, free of pits and pinholes; while the electrode slurry of Comparative Example 1 has bubbles, and after coating and drying, the corresponding electrode sheet coating has pits and depressions, and especially under 4.5 times magnification, the coating appearance surface has pinholes, pits and depressions.

[0077] The above examples only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as limiting the scope of the patent. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method of deaerating an electrode slurry, characterized by, The method comprises the following steps: obtaining an electrode slurry; defoaming the electrode slurry, wherein the defoaming of the electrode slurry is performed as follows: defoaming the electrode slurry once at a P1 vacuum degree; defoaming the electrode slurry twice at a P2 vacuum degree after the defoaming once; wherein P1 < 0, P2 < 0, and P1 < P2.

2. The method of claim 1, wherein the electrode slurry is defoamed by a method comprising: The transition between P1 and P2 is a gradient change.

3. The method of claim 1, wherein the electrode slurry is defoamed by a method comprising: defoaming the electrode slurry once at a P1 vacuum degree with a vacuum degree change rate of -1 kpa / s to -9 kpa / s; and / or defoaming the electrode slurry twice at a P2 vacuum degree after the defoaming once with a vacuum degree change rate of -1 kpa / s to -9 kpa / s.

4. The method of claim 1, wherein the electrode slurry is defoamed. P1 is selected from -90 kpa to -110 kpa; and / or P2 is selected from -40 kpa to -60 kpa.

5. The method of claim 1, wherein the electrode slurry is defoamed. The defoaming of the electrode slurry is performed under stirring; and / or The defoaming of the electrode slurry is performed at a temperature of 20℃ to 35℃; and / or The defoaming of the electrode slurry is repeated for ≥20 times.

6. An electrode slurry, characterized by, The electrode slurry comprises an active material, a binder, a solvent, and a conductive agent, wherein the active material, the binder, the solvent, and the conductive agent are mixed and treated by the defoaming method of the electrode slurry according to any one of claims 1 to 5, and the solvent is removed after the electrode slurry is dried.

7. The electrode paste of claim 6, wherein The active material is at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium nickel manganese oxide, lithium nickel oxide, and lithium-rich manganese-based positive electrode material; and / or The active material is at least one of silicon-carbon negative electrode material, silicon-oxygen negative electrode material, silicon-based negative electrode material, graphite, and hard carbon; and / or The binder is at least one of PVDF, PTFE, PI, CMC, SBR, and PAA; and / or The solvent is NMP or water; and / or The specific surface area of the conductive agent is ≥ 200 m 2 / g; and / or, The total content of the conductive agent in the electrode slurry is 0.5% to 4%.

8. A computer readable storage medium based on slurry debubbling, characterized in that, The computer program or instruction stored in the computer readable storage medium based on the defoaming of the slurry, when executed by a computing device, realizes the defoaming method of the electrode slurry according to any one of claims 1 to 5.

9. A pulping apparatus characterized in that, The electrode slurry is prepared by executing the preparation method of the slurry according to any one of claims 1 to 5.

10. A battery, characterized by The electrode slurry comprises at least an electrode sheet and an electrolyte, the electrolyte is in contact with the electrode sheet, and at least one side surface of the electrode sheet is coated with the electrode slurry according to claim 6 or 7.

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