CN110707268B

CN110707268B - SiO 2-polymer composite water-based battery diaphragm material and preparation method and application thereof

Info

Publication number: CN110707268B
Application number: CN201910332772.8A
Authority: CN
Inventors: 刘赛男; 蔡圳阳; 张强
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2019-04-24
Filing date: 2019-04-24
Publication date: 2022-01-11
Anticipated expiration: 2039-04-24
Also published as: CN110707268A

Abstract

The invention belongs to the field of water-based battery materials, and particularly discloses SiO₂-a polymer composite water-based battery separator material; for dispersing SiO₂A reticulated film material formed by the interaction of fibers of the hydrophilic polymer of the source. The invention also comprises the preparation and application of the diaphragm material, and also provides a water system zinc ion battery composed of special materials. The invention provides a brand-new technical idea of a water-based battery diaphragm, namely SiO₂The technical idea of polymer fiberization and interactive film forming is adopted to improve the wettability, hydrophilicity and flexibility of the aqueous solution, and effectively solve the problem of volatilization of the aqueous electrolyte solution, so that the performance of the water-based battery is effectively improved.

Description

SiO (silicon dioxide)2-polymer composite water-based battery diaphragm material and preparation method and application thereof

Technical Field

The invention relates to SiO₂A polymer water-retention composite battery diaphragm material, a preparation method and application thereof, belonging to the technical field of battery diaphragms.

Background

With the increasing depletion of fossil fuels such as coal and petroleum, energy issues are attracting more and more attention. Also, under strong academic and industrial demands, the development of high energy density and high power density batteries is stimulated. However, this work often faces several serious challenges related to safety failures and performance limitations of the battery. Among the various safety issues of batteries, internal short circuits are considered to be one of the most difficult key threats to avoid. The separator material in the cell is considered to be a critical component to prevent failure from occurring because its primary function is to maintain isolation between the cathode and anode. Another major function of the separator material is to allow transport of ions through its full liquid electrolyte. The ionic conductivity of the separator material depends largely on its porous structure, polarity, and electrolyte wettability, which affects the ohmic polarization of the cell. It is worth noting that this effect on cell polarization becomes more pronounced at the high current densities required for high power applications.

The commercial batteries are mainly organic electrolyte batteries (mainly lithium ion batteries), however, the organic electrolyte has the dangers of toxicity, harm, easy explosion and the like. Recently, researchers have been focusing on batteries with aqueous electrolytes (e.g., aqueous zinc ion batteries). The water-based battery uses water as an electrolyte formed by a solvent, the ion conductivity is two orders of magnitude higher than that of the former electrolyte, and the water-based battery has small harm to the environment and human bodies and higher safety. However, water is more volatile than organic solvents when used as a solvent, and this causes problems such as deterioration of the electrolyte solution and short-circuiting of the battery. Therefore, the prior art also discloses some improvement ideas, which mainly comprise: (1): coating a hydrophilic wetting active ingredient on the surface of the existing diaphragm base film by a coating method; (2): and carrying out hydrophilic modification on the molecular chain segment of the membrane material. (3): the porosity of the battery diaphragm is improved, so that the transmission rate of ions in the electrolyte is improved, and the electrochemical performance of the battery is enhanced.

In the prior art, a coating modification technology for a separator is a main means for improving the performance of a separator of an aqueous battery, and for example, chinese patent publication No. CN108039440A discloses an adhesive separator for a power battery, in which an oxide coating layer is coated on at least one surface of a base film, and an adhesive slurry layer is coated on at least one surface of the base film coated with the oxide coating layer. Chinese patent publication No. CN107611320A discloses an aqueous slurry for coating a separator for a lithium battery comprising water, a filler and an auxiliary agent, and discloses a separator material coated with the active ingredient. In addition, patent documents with publication numbers of US20160164060a1, CN105556702A, CN104157818A, JP2016025093A, etc. also disclose some similar coating solutions.

Technical difficulty in modifying the molecular chain segment of the membrane material is great and few technical means are disclosed so far, for example, U.S. patent document publication No. US20150333311a1 provides a microporous hybrid membrane capable of improving the reliability of a battery by simultaneously improving thermal stability and water-based property at high temperature, and a method for preparing the same.

In the prior art, some techniques for improving the porosity of the membrane to improve the performance of the separator have also been reported, for example, jiangson and the like (application publication No. CN201210281684.8) have improved the stability of the battery separator by preparing a porous composite coating polyolefin separator having high porosity, high gas permeability and high heat shrinkage deformation temperature, and having excellent heat resistance and dimensional stability.

In addition, the base film of the existing separator is mainly polyolefin such as Polyethylene (PE) and polypropylene (PP). The polyolefin membrane material has good physical and electrochemical properties in practical application. However, they have poor thermal stability, low porosity, insufficient wettability of electrolyte, and often affect ion transport between electrodes due to poor water retention during operation, and cause safety problems of internal short-circuit discharge.

Disclosure of Invention

Aiming at the problems of insufficient electrolyte wettability, poor water retention and the like of the existing water-based battery diaphragm material, the invention provides SiO₂The invention relates to a polymer composite water-based battery diaphragm material (also referred to as a diaphragm material for short) and aims to provide a novel diaphragm material which passes through a novel concept.

The second purpose of the invention is to provide the SiO₂A method for preparing a polymer composite water-based battery diaphragm material.

The third purpose of the invention is to provide the SiO₂-use of a polymer composite water-based battery separator material.

The requirements for the separator material are different according to different battery systems. For example, a separator is required to have high ion conductivity and high thermal stability in a general organic battery, and a separator is required to have high wettability to an electrolyte solution and long water retention time in a material in an aqueous battery. The purpose of the present invention is to provide an aqueous battery separator material having good hydrophilicity. However, most of the conventional water-based battery separator materials are surface-coated and modified on the basis of the conventional base film, and these conventional methods can achieve certain effects, but still have the problems of insufficient water retention, poor cycle performance, and the like. Therefore, the invention provides a water-based battery diaphragm material with a brand-new technical concept, which specifically comprises the following components:

SiO (silicon dioxide)₂-a polymer composite water-based battery separator material; for dispersing SiO₂A reticulated film material formed by the interaction of fibers of the hydrophilic polymer of the source.

Aiming at the requirements and characteristics of the water-based battery diaphragm, the invention departs from the inherent technical concept of the existing water-based diaphragm coating modification and provides a brand new technical concept that SiO is used₂The source and the polymer are fiberized, and a technical idea of film forming is interacted, so that the wettability, the hydrophilicity and the flexibility of the aqueous solution are improved, the volatilization of the aqueous electrolyte solution is effectively solved, and the performance of the water-based battery is effectively improved.

In the present invention, SiO is used innovatively₂The affinity to aqueous solutions is improved by the interaction between the source and the polymer component and the fibrous interactive structure of the synergistic component, and the flexibility is improved, thereby improving the performance of the aqueous battery. Compared with the prior art, the technical scheme of the invention does not need a polymer base film and surface modification of the base film, and can be directly used as a polymer diaphragm; moreover, the electrical performance of the composite material can be effectively improved.

Research shows that on the basis of the innovative concept of the invention, SiO is further controlled₂Particle size of source, kind of hydrophilic polymer, and SiO₂The ratio of source to hydrophilic polymer may further enhance the performance of the separator.

Preferably, the SiO₂The source is dispersed in the hydrophilic polymer, e.g., embedded, partially exposed; and SiO₂The source is uniformly dispersed in the hydrophilic polymer fiber system. SiO2₂The uniform dispersion of the source in the polymer facilitates uniform dispersion in the spun film, and canSo as to improve various performances of the diaphragm; if SiO₂The source is not uniformly dispersed or agglomerated, which is not only unfavorable for electrostatic spinning film formation, but also for SiO₂The source itself has adverse effects and reduces the various properties of the membrane.

Preferably, the SiO₂The source comprises amorphous SiO₂。

Preferably, SiO₂The source is a hydrophilic clay material, or a hydrophilic clay material pre-purified with an acid solution.

The hydrophilic clay material is preferably at least one of diatomite, sepiolite, halloysite.

Most preferably; the SiO₂The source is diatomite or at least one of acidified sepiolite and acidified halloysite.

Preferably, SiO₂The particle size of the source is 500-800 meshes. The research finds that the control of the preferred particle size can unexpectedly cooperate with the hydrophilic polymer and the special fiber interaction structure to improve the electrical property of the diaphragm in the water-based battery, and the particle size is too large to be miscible with the polymer and easily causes SiO₂Delamination from the polymer, affecting the performance of the separator; the particle size is too small, and the polymer can completely wrap SiO in the spinning process₂Thus, it cannot exert the hydrophilic and water-retaining effects.

Preferably, the hydrophilic polymer is PVA or PAN. The preferable polymer is more beneficial to the dispersion of the silicon dioxide, and the performance of the diaphragm can be further improved by matching the fiber interaction structure.

Preferably, the molecular weight of the hydrophilic polymer is 100000 to 200000. The polymer molecular weight is too small, so that the mechanical property of the diaphragm is easily reduced, the tensile strength, the breaking strength and the like are reduced, and even the phenomenon that the film cannot be formed during spinning can occur; the molecular weight of the polymer is increased, and the average cost of the polymer is increased, so that the commercial production and use of the diaphragm are not facilitated.

Preferably, SiO₂The mass ratio of the source to the hydrophilic polymer is 20-40: 60-80.

Preferably, said fibersThe diameter of the fiber is 400 nm-600 nm. When the diameter of the fiber is less than 400nm after spinning, the fiber is easy to break, the diaphragm is easy to break, when the diameter of the fiber is more than 600nm, the porosity of the diaphragm is greatly reduced, the absorption of electrolyte and the passing of ions in the electrolyte are not facilitated, and SiO is easy to completely wrap₂Particles, reducing their performance related properties.

Preferably, the porosity (pore area) of the separator material is 70% to 85%. The low porosity is not beneficial to the wetting of the electrolyte solution, the ion transmission rate can be reduced, the porosity is too high, the strength of the diaphragm is insufficient, and the diaphragm is easy to break and break.

The invention also provides the SiO₂A preparation method of-polymer composite water-based battery diaphragm material, which is prepared by mixing SiO₂Dispersing a source and a hydrophilic polymer in a solvent to obtain a spinning solution; carrying out electrostatic spinning on the spinning solution; and (5) obtaining the product.

The invention innovatively combines SiO₂An aqueous battery membrane material in which source and hydrophilic polymers are fiberized and are interlaced into a network, by which SiO can be overcome₂And the hydrophilic polymer phase compatibility problem, the dispersion effect of the hydrophilic polymer and the affinity for water can be improved, and the aqueous battery separator material with excellent performance can be prepared.

In the present invention, SiO₂The source being amorphous SiO₂The material can be directly a commercial pure product or a clay material, and the clay material can be selectively subjected to acid liquor purification treatment according to the needs and preparation requirements. The acid liquor purification treatment can be carried out by the existing means.

In the present invention, the solvent is a solvent that can dissolve the hydrophilic polymer, and is, for example, water.

In the present invention, the hydrophilic polymer may be dissolved in advance with a solvent, and then the SiO may be added₂And (4) uniformly stirring and dispersing to obtain the spinning solution.

The invention innovatively adopts an electrostatic spinning method to fibrillate the spinning solution and form a reticular membrane material in an interactive mode. Researches find that the control of parameters of the electrostatic spinning process is helpful for further obtaining the diaphragm material with excellent performance.

Preferably, the distance between the needle head and the receiving polar plate is 10-20 cm.

Preferably, the humidity in the electrostatic spinning machine is controlled to be 20-40%, the temperature is 20-45 ℃, the voltage of a positive electrode is 10-20 kV, the voltage of a negative electrode is 0-0.1 kV, the injection speed of the spinning solution is 0.01-0.1 mm/min, the spinning time is 3-10 h, and the rotating speed of a receiver is 50-150 r/min.

An optimized SiO of the invention₂A preparation method of PVA water-retention composite water-based battery diaphragm material; the method comprises the following steps:

step one

Adding PVA powder according to a designed proportion, and mixing the PVA powder: adding deionized water in a proportion of 1g to 3-10 mL, stirring and mixing uniformly at 80-95 ℃ to ensure that PVA is fully dissolved in the deionized water;

step two

Adding diatomite powder into deionized water according to a designed ratio, wherein the weight ratio of the diatomite powder: 3-10 mL of deionized water, and ultrasonically stirring and uniformly mixing at room temperature;

step three

Mixing the solutions obtained in the first step and the second step, stirring uniformly, then extracting the mixed solution by using a medical injector, and drying the mixed solution in vacuum for 10 to 30 hours at the temperature of between 30 and 70 ℃ by using an electrostatic spinning method to obtain SiO₂PVA water-retaining composite battery diaphragm material.

Preferably, in the first step and the second step, PVA powder and diatomite powder are prepared according to the design proportion and proportion as raw materials, and the prepared raw materials are uniformly dissolved in the solution according to the third step to obtain a mixture solution; the average grain diameter of the PVA powder is 300-500 meshes, and the average grain diameter of the diatomite powder is 500-800 meshes.

Preferably, when the solutions in the first step and the second step are mixed, the stirring speed is controlled to be 400 r/min-800 r/min, the stirring time is controlled to be 30 min-150 min, the ultrasonic power of an instrument is controlled to be 50W-100W, and the ultrasonic time is controlled to be 10 min-30 min.

Preferably, the electrospinning method in the third step comprises the following steps of: firstly, a medical injector of 10-25 mL is used for extracting 5-20 mL of uniformly mixed solution, a flat-mouth stainless steel needle of 18-20 is selected to be connected with the injector, and the stainless steel needle is connected with the anode of a high-voltage power supply; secondly, sticking the cut aluminum foil on a receiving polar plate connected with the negative electrode of the high-voltage power supply for spraying a mixed solution on the surface of the aluminum foil; then, the distance between the needle head and the receiving polar plate is set to be 10-50 cm.

Preferably, in the third step, the humidity in the electrostatic spinning machine is controlled to be 20-40%, the temperature is 20-45 ℃, the positive voltage is 10-20 kV, the negative voltage is 0-0.1 kV, and SiO is controlled during the experiment of the electrostatic spinning method₂The PVA solution injection speed is 0.01-0.1 mm/min, the spinning time is 3-10 h, and the receiver rotation speed is 50-150 r/min.

The invention also provides the SiO₂-use of a polymer composite water-based battery separator material as a separator for a water-based battery; preferably used as a separator of an aqueous zinc ion battery.

The invention also provides a water-based zinc ion battery comprising the SiO₂-polymer composite water-based battery separator material.

Preferably, in the aqueous zinc-ion battery, the positive electrode material contains V₂O₅The one-dimensional clay material and hydrogen peroxide are subjected to hydrothermal reaction to prepare gel, and then the gel is subjected to freeze drying to obtain the material.

Found to contain V₂O₅The one-dimensional clay material and hydrogen peroxide are subjected to hydrothermal and freeze drying to obtain the novel anode material with the self-supporting morphology, and the anode material can be directly used as an anode without using a current collector as a carrier. Moreover, the system adaptation between the positive electrode and the diaphragm of the invention is beneficial to further improving the comprehensive performance of the battery in a synergistic way.

Principles and advantages

1. The invention provides a brand new water-based battery diaphragm material under the brand new technical conception.

2. The novel composite water-based battery diaphragm material has excellent hydrophilicity and water retention, ensures full contact and ion migration of electrolyte and the diaphragm, can effectively slow down the volatilization of the electrolyte, and enhances the durability and safety of the battery.

3. The material of the invention overcomes the defects of the prior art, makes up the defects of the prior battery electrolyte diaphragm material and realizes the SiO₂The composite diaphragm material has excellent hydrophilicity and water retention property by being uniformly and effectively compounded with hydrophilic polymers, so that the electrolyte solution can be stored in the battery for a long time, ions can be transmitted without obstruction, and the service life of the battery is greatly prolonged

4. The diaphragm material provided by the invention does not need a base film material, and can be directly used as a diaphragm material.

5. The raw materials are cheap and have wide sources, and the preparation cost of the battery diaphragm is greatly reduced; the diaphragm material has high safety and is environment-friendly, thereby conforming to the national policy of sustainable development.

Drawings

FIG. 1 is an XRD diffraction spectrum of a clay powder;

FIG. 2 is a scanning electron micrograph of an electrospun membrane;

FIG. 3 is a graph of contact angle for example battery separator material;

FIG. 4 is a graph showing the water retention performance of the examples.

FIG. 5 is a schematic view of the diaphragm flexibility;

FIG. 6 is a graph of contact angle of separator material for a comparative example battery;

FIG. 7 is a graph showing the water retention property test of the comparative example.

Detailed Description

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

The purities of PVA and PAN powder are analytical and pure, and the molecular weights of the following cases are 100000-200000 except special statement; the average grain diameter is 300-500 meshes, and SiO in clay raw ore such as diatomite powder and sepiolite₂Should be greater than 90%; the average grain diameter is 500-800 meshes.

Example 1

(1) Preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600-mesh diatomite powder (the mass ratio of PVA to diatomite is 65:35) into deionized water according to the mass percentage, and mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; stirring and mixing the PVA solution and the diatomite solution uniformly, wherein the stirring speed is 600r/min, the stirring time is 60min, and the diffraction pattern of the diatomite powder is shown as figure 1 a.

(2) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂A PVA composite membrane, wherein the humidity in the electrostatic spinning machine is controlled to be 30%, the temperature is 37 ℃, the voltage of a positive electrode is 15kV, the voltage of a negative electrode is 0.05kV, the injection speed is 0.05mm/min, the spinning time is 5h, and the rotating speed of a receiver is 100 r/min.

(3) And (3) vacuum drying: taking the SiO obtained in the step (2)₂Vacuum drying at 60 deg.c for 12 hr to obtain SiO₂The microstructure of the PVA water-retaining composite battery diaphragm material is shown in a scanning electron microscope picture 2. The diameter of the fiber is 200nm-700 nm; the membrane porosity was about 72%.

(4) Contact Angle test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a contact angle test, water drops are dripped on the surface of the composite diaphragm material, the contact angle is 18.25 degrees according to a three-point method, and the PVA water-retaining composite battery diaphragm material has excellent hydrophilicity, as shown in figure 3 a.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is placed in the open air for 10 days, the water is still retained, and the water volatilization rate is about 43 percent, as shown in figure 4 a.

(6) Assembling an aqueous zinc ion battery: first, (3) inThe resulting SiO₂The PVA water-retaining composite battery diaphragm material is cut into a circular sheet with the diameter of 12mm and is reserved for standby; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(7) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1Has 176mAh g after circulating for 200 circles under the current of (1)^-1The capacity of (a); and the diaphragm still has a certain flexibility after being taken out, as shown in figure 5.

Example 2

(1) Preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PVA and diatomite are 70:30 in mass ratio) powder into deionized water according to mass percent, mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(2) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂-PVA composite film, static controlThe humidity in the spinning machine is 30%, the temperature is 37 ℃, the voltage of the positive electrode is 15kV, the voltage of the negative electrode is 0.05kV, the injection speed is 0.05mm/min, the spinning time is 5h, and the rotating speed of the receiver is 100 r/min.

(3) And (3) vacuum drying: taking the SiO obtained in the step (2)₂Vacuum drying at 60 deg.c for 12 hr to obtain SiO₂PVA water-retaining composite battery diaphragm material.

(4) Contact Angle test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a contact angle test, a water drop is dropped on the surface of the composite diaphragm material, the contact angle is 20.74 degrees according to a three-point method, and the PVA water-retaining composite battery diaphragm material has excellent hydrophilicity, as shown in figure 3 b.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is placed in the open air for 10 days, the water is still retained, and the water volatilization rate is about 50 percent, as shown in figure 4 b.

(6) Assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is cut into a circular sheet with the diameter of 12mm and is reserved for standby; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(7) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1After circulating for 200 cycles, the current still has 180mAh g^-1The capacity of (c).

Example 3

(1) Preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PVA and diatomite in a mass ratio of 77:23) powder into deionized water according to mass percent, mixing the weight percentage of the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(4) Contact Angle test: for SiO obtained in (3)₂The PVA water-retention composite battery diaphragm material is subjected to a contact angle test, water drops are dripped on the surface of the composite diaphragm material, the contact angle is 16.15 degrees according to a three-point method, and the PVA water-retention composite battery diaphragm material has excellent hydrophilicity, as shown in figure 3 c.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is placed in the open air for 10 days, the water is still retained, and the water volatilization rate is about 58%, as shown in figure 4 c.

(6) Assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is cut into a circular sheet with the diameter of 12mm and is reserved for standby; it is composed ofSecondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(7) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1After circulating for 200 cycles, the current still has 159mAh g^-1The capacity of (c).

Example 4

The sepiolite is used as a raw material, and specifically comprises the following steps:

(1) pre-treating sepiolite: mixing sepiolite with purity of more than 90% by mixing sepiolite powder: 4mol/l hydrochloric acid is mixed for 8 hours at 85 ℃ in a proportion of 1g50mL, and the stirring speed is 700 r/min; then centrifugally washing the acid-leached sepiolite, drying the sepiolite for 24 hours at 60 ℃, grinding the sepiolite until the particle size is 500-800 meshes, and reserving the sepiolite for later use, wherein the processed sepiolite is basically amorphous SiO (silicon dioxide) as shown in an XRD (X-ray diffraction) pattern 1b₂。

(2) Preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600-mesh pretreated sepiolite powder (the mass ratio of PVA to pretreated sepiolite is 70:30) into deionized water according to the mass percentage, and mixing the pretreated sepiolite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; and uniformly stirring and mixing the PVA solution and the pretreated sepiolite solution at the stirring speed of 600r/min for 60 min.

(3) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂A PVA composite membrane, wherein the humidity in the electrostatic spinning machine is controlled to be 30%, the temperature is 37 ℃, the voltage of a positive electrode is 15kV, the voltage of a negative electrode is 0.05kV, the injection speed is 0.05mm/min, the spinning time is 5h, and the rotating speed of a receiver is 100 r/min.

(4) And (3) vacuum drying: taking the SiO obtained in the step (2)₂Vacuum drying at 60 deg.c for 12 hr to obtain SiO₂PVA water-retaining composite battery diaphragm material.

(5) Contact Angle test: for SiO obtained in (3)₂The PVA water-retention composite battery diaphragm material is subjected to a contact angle test, water drops are dripped on the surface of the composite diaphragm material, the contact angle is 22.16 degrees according to a three-point method, and the PVA water-retention composite battery diaphragm material has excellent hydrophilicity, as shown in figure 3 d.

(6) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is placed in the open air for 10 days, the water is still retained, and the water volatilization rate is about 40 percent, as shown in figure 4 d.

(7) Assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is cut into a circular sheet with the diameter of 12mm and is reserved for standby; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; finally, the positive electrode shell of the battery is covered and putAnd (5) maintaining the pressure in a special battery press for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(8) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1After circulating for 200 cycles, the current still has 160mAh g^-1The capacity of (c).

Example 5

In this case, the polymer is PAN, specifically as follows:

(1) preparing an electrostatic spinning solution: adding 400-mesh PAN powder according to mass percent, and mixing the materials in percentage by mass as PAN powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PAN and diatomite in a mass ratio of 70:30) powder into deionized water according to mass percentage, and mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; and uniformly stirring and mixing the PVA solution and the diatomite solution at the stirring speed of 600r/min for 60 min.

(2) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂And (3) controlling the humidity in the electrostatic spinning machine to be 30%, the temperature to be 37 ℃, the voltage of a positive electrode to be 15kV, the voltage of a negative electrode to be 0.05kV, the injection speed to be 0.05mm/min, the spinning time to be 5h and the rotating speed of a receiver to be 100 r/min.

(3) And (3) vacuum drying: taking the SiO obtained in the step (2)₂Vacuum drying the-PAN composite membrane at the temperature of 60 ℃ for 12h to obtain SiO₂-a PAN water-retaining composite battery separator material.

(4) Contact Angle test: for SiO obtained in (3)₂The PAN water-retention composite battery diaphragm material is subjected to a contact angle test, a water drop is dropped on the surface of the composite diaphragm material, the contact angle is 26.23 degrees according to a three-point method, and the PAN water-retention composite battery diaphragm material has excellent hydrophilicity, and is shown in figure 3 e.

(5) Water retention property test: for SiO obtained in (3)₂The PAN water-retention composite battery diaphragm material is subjected to a water retention performance test, the diaphragm is wetted and is placed in the open air for 10 days, the water is still retained, and the water volatilization rate is about 48%, as shown in figure 4 e.

(6) Assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂-PAN water-retaining composite battery diaphragm material, which is cut into a circular sheet with the diameter of 12mm and kept for standby; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PAN water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(7) SiO prepared in this example₂the-PAN water-retention composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the power consumption is 500 mA.g^-1After circulating for 200 circles, the current still has 185mAh g^-1The capacity of (c).

Example 6

(1) Preparing an electrostatic spinning solution: adding 500-mesh PVA powder according to the mass percentage, mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 700-mesh diatomite (PVA and diatomite in a mass ratio of 77:23) powder into deionized water according to mass percentage, mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(4) Contact Angle test: for SiO obtained in (3)₂And (3) carrying out a contact angle test on the PVA water-retaining composite battery diaphragm material, dripping water drops on the surface of the composite diaphragm material, and measuring the contact angle to be 21.74 degrees according to a three-point method, wherein the hydrophilicity is good, and the method is shown in figure 3 f.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is placed in the open air for 10 days to be almost completely dried, and the water volatilization rate is about 42 percent, as shown in figure 4 f.

(7) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1After circulating for 200 circles under the current of (1), 180mAh & g still exist^-1The capacity of (c).

Example 7

The transformation mode parameters are specifically as follows:

(1) preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600-mesh diatomite powder (the mass ratio of PVA to diatomite is 65:35) into deionized water according to the mass percentage, and mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(2) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂A PVA composite membrane, wherein the humidity in the electrostatic spinning machine is controlled to be 35%, the temperature is 30 ℃, the voltage of a positive electrode is 10kV, the voltage of a negative electrode is 0.02kV, the injection speed is 0.03mm/min, the spinning time is 8h, and the rotating speed of a receiver is 150 r/min.

(4) Contact Angle test: for SiO obtained in (3)₂The PVA water-retention composite battery diaphragm material is subjected to a contact angle test, water drops are dripped on the surface of the composite diaphragm material, the contact angle is 16.26 degrees according to a three-point method, and the PVA water-retention composite battery diaphragm material has excellent hydrophilicity, as shown in figure 3 g.

(5) Water retention property test: for SiO obtained in (3)₂-PVA water-retaining composite batteryThe membrane material was tested for water retention, the membrane was wetted and left open for 10 days, still retaining water, with a moisture evaporation rate of about 52%, as shown in fig. 4 g.

(7) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1After circulating for 200 cycles, the current still has 182mAh g^-1The capacity of (c).

Example 8

The diaphragm of the invention is cooperated with a special anode material, and the specific steps are as follows:

(1) pre-treating sepiolite: the sepiolite raw ore is treated by 4mol/L hydrochloric acid at 85 ℃ for 8 hours (the proportion of the sepiolite raw ore to the hydrochloric acid is 1g:50mL), dried at 80 ℃ for 24 hours and ground to the particle size of 500 meshes for later use.

(2) Preparing a vanadium-based carbon nanotube sepiolite composite positive electrode: by mass percent, 60% V is firstly added₂O₅Powder of V₂O₅Powder: h₂O₂Adding H into the solution at a ratio of 1g to 50mL₂O₂Ultrasonically stirring the solution at 5 deg.C for 20min at 100W and stirring rate of 500r/min, and the stirring time is 20 min; secondly, adding 40% of pretreated sepiolite powder into the mixed solution obtained in the previous step according to the mass percentage, and continuing stirring and ultrasonic treatment until the solution is uniformly mixed, wherein the stirring speed is 600r/min, and the stirring time is 40 min; then pouring the mixed solution obtained in the previous step into a high-temperature high-pressure reaction kettle, placing the reaction kettle in a drying oven, keeping the temperature at 180 ℃, and reacting for 24 hours; and finally, treating the reacted sample for 48 hours under the condition of freeze drying at the temperature of-60 to-55 ℃ to obtain the vanadium-based sepiolite composite positive electrode material for later use.

(3) Preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PVA and diatomite are 70:30 in mass ratio) powder into deionized water according to mass percent, mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(4) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂A PVA composite membrane, wherein the humidity in the electrostatic spinning machine is controlled to be 30%, the temperature is 37 ℃, the voltage of a positive electrode is 15kV, the voltage of a negative electrode is 0.05kV, the injection speed is 0.05mm/min, the spinning time is 5h, and the rotating speed of a receiver is 100 r/min.

(5) And (3) vacuum drying: taking the SiO obtained in the step (2)₂Vacuum drying at 60 deg.c for 12 hr to obtain SiO₂PVA water-retaining composite battery diaphragm material.

(6) Contact Angle test: for SiO obtained in (3)₂The PVA water-retention composite battery diaphragm material is subjected to a contact angle test, water drops are dripped on the surface of the composite diaphragm material, the contact angle is 20.52 degrees according to a three-point method, and the PVA water-retention composite battery diaphragm material has excellent hydrophilicity, as shown in figure 3 h.

(7) Water retention property test: for SiO obtained in (3)₂The PVA water-retention composite battery diaphragm material is subjected to a water retention performance test, the diaphragm is wetted and is placed in the open air for 10 days, the water is still retained, and the water volatilization rate is about 50%, as shown in figure 4 h.

(8) Assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is cut into a circular sheet with the diameter of 12mm and is reserved for standby; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Placing the vanadium-based sepiolite composite anode material as an anode on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(9) SiO prepared in this example₂The PVA water-retaining composite battery diaphragm material water-based zinc ion battery has high capacity and long cycle performance, and the capacity is 500 mA.g^-1After circulating for 200 circles under the current of (1), 189mAh g is still obtained^-1The capacity of (c).

The above description is only a preferred embodiment of the present invention, and therefore should not be taken as limiting the scope of the invention, which is defined by the appended claims.

Comparative example 1

Compared with example 1, the difference is that no silica raw material (diatomite) is added, and the concrete steps are as follows:

(1) preparing an electrostatic spinning solution: only 400 mesh PVA powder was added, as PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min.

(2) Electrostatic spinning: and (3) extracting 8mL of the electrostatic spinning solution obtained in the step (1) by using a 10mL medical injector, and carrying out electrostatic spinning to obtain a PVA composite membrane, wherein the humidity in the electrostatic spinning machine is controlled to be 30%, the temperature is 37 ℃, the positive voltage is 15kV, the negative voltage is 0.05kV, the injection speed is 0.05mm/min, the spinning time is 5h, and the rotating speed of a receiver is 100 r/min.

(3) And (3) vacuum drying: and (3) taking the PVA film obtained in the step (2), and drying the PVA film at the temperature of 60 ℃ for 12 hours in vacuum to obtain the PVA battery diaphragm material.

(4) Contact Angle test: and (3) carrying out a contact angle test on the PVA composite battery separator material obtained in the step (3), dripping water drops on the surface of the composite separator material, and measuring that the contact angle is 95.1 degrees and the hydrophilicity is poor according to a three-point method, wherein the contact angle is shown in figure 6 a.

(5) Water retention property test: and (3) carrying out a water retention performance test on the PVA battery diaphragm material obtained in the step (3), wetting the diaphragm, and after the diaphragm is placed in the open air for 10 days, almost completely drying the diaphragm, wherein the water evaporation rate is about 95%, as shown in the attached figure 7 a.

(6) Assembling an aqueous zinc ion battery: firstly, cutting the PVA battery diaphragm material obtained in the step (3) into a wafer with the diameter of 12mm and reserving the wafer for later use; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, then a PVA battery diaphragm is put on, and 3 drops of 2mol/L ZnSO are dropped₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(5) The PVA battery diaphragm material prepared by the comparative example has poor electrochemical performance of a water-based zinc ion battery at 500 mA.g^-1After 50 cycles of charge and discharge under the current of (4), the electrochemical capacity is sharply reduced to 80mAh g^-1The capacity of (c).

Comparative example 2

Compared with the example 1, the proportion of PVA and diatomite is not controlled within the required range, and the specific ratio is as follows:

(1) preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PVA and diatomite are in a mass ratio of 35:65) powder into deionized water according to mass percent, mixing the weight percentage of the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(4) Contact Angle test: for SiO obtained in (3)₂And (3) carrying out a contact angle test on the PVA water-retaining composite battery diaphragm material, dripping water drops on the surface of the composite diaphragm material, and measuring that the contact angle is 99.5 degrees according to a three-point method, the hydrophilicity is poor, and the contact angle is smaller, as shown in figure 6 b.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is placed in the open air for 10 days, the moisture content of the diaphragm is very low, and the moisture volatilization rate is about 85 percent, as shown in figure 7 b. ,

(6) assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is cut into a circular sheet with the diameter of 12mm and is reserved for standby; secondly, the negative electrode of the battery is arranged in the shellA round zinc plate with the diameter of 12mm is placed with the part facing upwards as a negative electrode, and 3 drops of 2mol/L ZnSO are dripped₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(7) SiO prepared by the comparative example₂The PVA water-retention composite battery diaphragm material water-based zinc ion battery has lower capacity and poorer electrochemical performance. At 500mA · g^-1After 50 cycles of charge and discharge under the current of (4), the electrochemical capacity is sharply reduced to 103mAh g^-1The capacity of (c).

Comparative example 3

(1) preparing an electrostatic spinning solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PVA and diatomite are in a mass ratio of 25:75) powder into deionized water according to mass percent, mixing the weight percentage of the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(2) Electrostatic spinning: the electrospinning solution obtained in (1) was extracted with 8mL of a 10mL medical syringe and electrospun to obtain SiO₂-PVA composite film, controlling humidity in electrostatic spinning machine to be 30%, temperature to beThe voltage of the anode is 15kV, the voltage of the cathode is 0.05kV, the injection speed is 0.05mm/min, the spinning time is 5h, and the rotating speed of the receiver is 100r/min at 37 ℃.

(4) Contact Angle test: for SiO obtained in (3)₂And (3) carrying out a contact angle test on the PVA water-retention composite battery diaphragm material, dripping water drops on the surface of the composite diaphragm material, and measuring that the contact angle is 104.6 degrees according to a three-point method, the hydrophilicity is poor, and the contact angle is smaller, as shown in figure 6 c.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is almost dry after being placed in the open air for 10 days, and the water volatilization rate is about 90 percent, as shown in figure 7 c.

(7) SiO prepared by the comparative example₂The PVA water-retention composite battery diaphragm material has lower water-system zinc ion battery capacity and poorer electrochemical performance, and the capacity is 500 mA.g^-1After 50 cycles of charge and discharge under the current of (4), the electrochemical capacity is sharply reduced to 79mAh g^-1The capacity of (c).

Comparative example 4

The difference from example 1 is that no polymer material (PVA) was added, specifically as follows:

(1) preparing an electrostatic spinning solution: only 600 mesh diatomaceous earth powder was added, as diatomaceous earth powder: adding 8mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min;

(2) electrostatic spinning: and (2) extracting 8mL of the electrostatic spinning solution obtained in the step (1) by using a 10mL medical injector, performing electrostatic spinning, controlling the humidity in the electrostatic spinning machine to be 30%, the temperature to be 37 ℃, the positive voltage to be 15kV, the negative voltage to be 0.05kV, the injection speed to be 0.05mm/min, the spinning time to be 5h, the rotating speed of a receiver to be 100r/min, and directly dropping liquid drops, so that a spinning film cannot be prepared.

(3) In the comparative example, because PVA is not added, electrostatic spinning can not form a film, and the preparation of the diaphragm material fails.

Comparative example 5:

common coating comparative examples are specified below:

compared with example 1, the preparation method is changed to apply the mixed solution to the surface of the commercial PP diaphragm, and the specific steps are as follows:

(1) preparation of coating solution: adding 400-mesh PVA powder according to the mass percentage, and mixing the PVA powder: adding 4mL of deionized water into the deionized water at a ratio of 1g to 10mL, and uniformly stirring and mixing the mixture at 90 ℃, wherein the stirring speed is 600r/min, and the stirring time is 120 min; adding 600 meshes of diatomite (PVA and diatomite are 70:30 in mass ratio) powder into deionized water according to mass percent, mixing the diatomite powder: adding 4mL of deionized water into deionized water at a ratio of 1g to 20mL, performing ultrasonic treatment at room temperature, stirring and mixing uniformly, controlling the ultrasonic power of an instrument to be 80W, performing ultrasonic treatment for 20min, and performing stirring at a stirring speed of 500r/min for 60 min; the PVA solution and the diatomite solution are stirred and mixed evenly, the stirring speed is 600r/min, and the stirring time is 60 min.

(2) Coating to the surface of a PP separator: the coating solution obtained in (1) was directly coated on the surface of a commercial PP separator by a coater to a coating thickness of 10 μm.

(3) And (3) vacuum drying: taking the coating film obtained in the step (2), and drying for 12 hours in vacuum at the temperature of 60 ℃ to obtain SiO₂-a PVA-PP coated separator material.

(4) Contact Angle test: for SiO obtained in (3)₂And (3) carrying out a contact angle test on the PVA water-retaining composite battery diaphragm material, dripping water drops on the surface of the composite diaphragm material, and measuring that the contact angle is 98.56 degrees according to a three-point method, the hydrophilicity is poor, and the contact angle is larger, as shown in figure 6 d.

(5) Water retention property test: for SiO obtained in (3)₂The PVA water-retaining composite battery diaphragm material is subjected to a water-retaining performance test, the diaphragm is wetted and is almost dry after being placed in the open air for 10 days, and the water volatilization rate is about 85 percent, as shown in figure 7 d.

(6) Assembling an aqueous zinc ion battery: first, SiO obtained in (3)₂-PVA-PP coating the membrane material, cut into disks with a diameter of 12mm and left for use; secondly, placing a round zinc sheet with the diameter of 12mm as a negative electrode with the interior of the negative electrode shell of the battery facing upwards, and then dripping 3 drops of 2mol/L ZnSO₄The solution is used as electrolyte, and then SiO is put on₂-PVA water-retaining composite battery diaphragm, and 3 drops of 2mol/L ZnSO₄(ii) a Will V₂O₅Grinding conductive carbon black (super P) and sodium carboxymethylcellulose (CMC) according to the mass ratio of 8:1:1 for 30min, uniformly mixing, coating on a copper foil, vacuum drying at the temperature of 60 ℃ for 24h, cutting the copper foil coated with the mixture into a wafer with the diameter of 12mm, and placing on a diaphragm; and finally, covering the positive electrode shell of the battery, putting the positive electrode shell into a special battery press, maintaining the pressure for 30s, and wiping off redundant electrolyte to obtain the water-based zinc ion battery.

(7) SiO prepared by the comparative example₂The PVA-PP coating diaphragm material water system zinc ion battery has lower capacity and poorer electrochemical performance, and the capacity is 500 mA.g^-1After 50 cycles of charge and discharge under the current of (4), the electrochemical capacity is sharply reduced to 115mAh g^-1The capacity of (c).

Claims

1. SiO (silicon dioxide)₂-a polymer composite water-based battery separator material; it is characterized in that SiO is dispersed₂A reticulated film material formed by the interaction of fibers of a source of hydrophilic polymer; by mixing SiO₂Dispersing a source and a hydrophilic polymer in a solvent to obtain a spinning solution; carrying out electrostatic spinning on the spinning solution to obtain the spinning solution;

SiO₂the source is diatomite or at least one of acidified sepiolite and acidified halloysite;

SiO₂the mass ratio of the source to the hydrophilic polymer is 20-40: 60-80 parts;

SiO₂the grain size of the source is 500-800 meshes;

the molecular weight of the hydrophilic polymer is 100000-200000;

the hydrophilic polymer is at least one of PVA and PAN;

the solvent is a solvent capable of dissolving the hydrophilic polymer.

2. SiO as claimed in claim 1₂-a polymer composite water-based battery separator material; the diaphragm material is characterized in that the porosity of the diaphragm material is 70-85%.

3. SiO as claimed in claim 1₂-a polymer composite water-based battery separator material; the fiber is characterized in that the diameter of the fiber is 400 nm-600 nm.

4. SiO as claimed in claim 1₂-a polymer composite water-based battery separator material; the electrostatic spinning method is characterized in that the electrostatic spinning process comprises the following steps: the distance between the needle head and the receiving polar plate is 10-20 cm;

controlling the humidity in the electrostatic spinning machine to be 20-40%, the temperature to be 20-45 ℃, the voltage of a positive electrode to be 10-20 kV, the voltage of a negative electrode to be 0-0.1 kV, the injection speed of the spinning solution to be 0.01-0.1 mm/min, the spinning time to be 3-10 h, and the rotating speed of a receiver to be 50-150 r/min.

5. The SiO of any of claims 1 to 4₂-polymer complexesThe application of the water-based battery separator material is characterized in that the material is used as a separator of a water-based battery.

6. An aqueous zinc ion battery comprising the SiO of any one of claims 1 to 4₂-polymer composite water-based battery separator material.

7. The aqueous zinc-ion battery according to claim 6, wherein the positive electrode material of the aqueous zinc-ion battery comprises V₂O₅The one-dimensional clay material and hydrogen peroxide are subjected to hydrothermal reaction to prepare gel, and then the gel is subjected to freeze drying to obtain the material.