Polymer porous membrane, preparation method thereof, polymer electrolyte, polymer battery and preparation method of battery

Abstract

The invention provides a polymer porous membrane, a preparation method of the polymer porous membrane, a polymer electrolyte, a polymer battery and a preparation method of the polymer battery. A carbon material is dispersed in the polymer porous membrane, so that the degree of crystallization of a polymer which constitutes the polymer porous membrane is lowered and the liquid absorption of the polymer porous membrane is increased; the liquid absorption rate, liquid holding capability and ionic conductivity of the polymer porous membrane are increased; interface impedance is reduced, battery magnification discharging performance and the circulating performance of the battery are enhanced; simultaneously, the battery prepared by the method has excellent high temperature circulation and storage performance and low expansion ratio at a high temperature and further meets the development requirement of the polymer battery. Simultaneously, the preparation method is simple and is easy to implement and the prepared battery has high performance.

Description

technical field

[0001] The invention belongs to the field of polymer batteries, and in particular relates to a polymer porous membrane, a preparation method of the polymer porous membrane, a polymer electrolyte, a polymer battery and a preparation method of the battery. Background technique

[0002] Polymer porous membranes are generally organic polymer porous membranes, which are easy to prepare, have excellent mechanical properties and permeability, and are widely used in various fields such as batteries and proton exchange.

[0003] Especially because of its excellent heat resistance and ion conduction ability, it is generally used as a battery separator and an indispensable and important part of the battery.

[0004] Existing battery separators generally use polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polyethylene (PE) or polypropylene (PP) single-layer membrane or PP / PE / PP three-layer composite with little difference in pore size. Membranes, and p...

Examples

preparation example Construction

[0028]The present invention also provides a preparation method for the above-mentioned porous diaphragm, which includes adding carbon materials, polymers and pore-forming agents into a solvent for mixing, forming a film, and volatilizing the pore-forming agents and solvents to obtain a polymer porous film. Among them, the carbon material in the present invention is preferably one or more of acetylene black, activated carbon, graphite, carbon fiber and carbon nanotubes, etc.; the polymer in the present invention is not particularly limited, and is selected according to the requirements of the prepared polymer porous membrane; The pore-forming agent and solvent are not particularly limited in the present invention, and can be various substances commonly used by those skilled in the art that can decompose or volatilize and finally form pores on the membrane. For example, the pore-forming agent can be selected from conventional water, toluene, ethanol, butanol , glycerol, isopropan...

Embodiment 1

[0042] Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with a content of 6wt% is dissolved in a mixture of 88wt% acetone, 5wt% water and 1wt% acetylene black (the average particle size of the crystal particles is 0.02 μm) solution, after stirring for one hour. It is coated on a polyethylene film (PE) with a thickness of 16 μm and a porosity of 40%, cast into a film, the thickness of the film is 10 μm, and dried to obtain a porous polymer film with a porosity of 45% and an average pore diameter of 90nm.

[0043] The positive electrode sheet coated with lithium cobaltate, the polymer porous membrane prepared above, and the negative electrode sheet coated with graphite are wound to form a pole core, which is inserted into the aluminum-plastic composite film. Prepare a lithium hexafluorophosphate electrolyte solution containing 20 wt% of methyl methacrylate monomer, 0.1 wt% of dibenzoyl peroxide and 1M lithium hexafluorophosphate, wherein EC / DMC=1:1 (volume ratio). The abo...

Embodiment 2

[0045] Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with a content of 5wt% is dissolved in a mixture of 83wt% acetone, 10wt% ethanol and 2wt% acetylene black (the average particle size of the crystal particles is 0.02 μm) After stirring for one hour, it is coated on a polyethylene film (PE) with a thickness of 16 μm and a porosity of 40%, and cast into a film. The thickness of the film is 12 μm, and the porosity is 38% after drying. The first porous polymer film was 86 nm. Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with a content of 6wt% was dissolved in 81wt% methyl ethyl ketone, 12wt% toluene and 1wt% acetylene black (the average particle size of the crystal particles was 0.01 μm) In the mixed solution, after stirring for one hour, coat the surface of the first porous polymer membrane prepared above, cast it into a membrane, the thickness of the membrane is 8 μm, and dry to obtain the first porous polymer membrane with a porosity of 50% and an average p...

technical field

[0001] The invention belongs to the field of polymer batteries, and in particular relates to a polymer porous membrane, a preparation method of the polymer porous membrane, a polymer electrolyte, a polymer battery and a preparation method of the battery. Background technique

[0002] Polymer porous membranes are generally organic polymer porous membranes, which are easy to prepare, have excellent mechanical properties and permeability, and are widely used in various fields such as batteries and proton exchange.

[0003] Especially because of its excellent heat resistance and ion conduction ability, it is generally used as a battery separator and an indispensable and important part of the battery.

[0004] Existing battery separators generally use polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polyethylene (PE) or polypropylene (PP) single-layer membrane or PP / PE / PP three-layer composite with little difference in pore size. Membranes, and p...

Examples

preparation example Construction

[0028]The present invention also provides a preparation method for the above-mentioned porous diaphragm, which includes adding carbon materials, polymers and pore-forming agents into a solvent for mixing, forming a film, and volatilizing the pore-forming agents and solvents to obtain a polymer porous film. Among them, the carbon material in the present invention is preferably one or more of acetylene black, activated carbon, graphite, carbon fiber and carbon nanotubes, etc.; the polymer in the present invention is not particularly limited, and is selected according to the requirements of the prepared polymer porous membrane; The pore-forming agent and solvent are not particularly limited in the present invention, and can be various substances commonly used by those skilled in the art that can decompose or volatilize and finally form pores on the membrane. For example, the pore-forming agent can be selected from conventional water, toluene, ethanol, butanol , glycerol, isopropan...

Embodiment 1

[0042] Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with a content of 6wt% is dissolved in a mixture of 88wt% acetone, 5wt% water and 1wt% acetylene black (the average particle size of the crystal particles is 0.02 μm) solution, after stirring for one hour. It is coated on a polyethylene film (PE) with a thickness of 16 μm and a porosity of 40%, cast into a film, the thickness of the film is 10 μm, and dried to obtain a porous polymer film with a porosity of 45% and an average pore diameter of 90nm.

[0043] The positive electrode sheet coated with lithium cobaltate, the polymer porous membrane prepared above, and the negative electrode sheet coated with graphite are wound to form a pole core, which is inserted into the aluminum-plastic composite film. Prepare a lithium hexafluorophosphate electrolyte solution containing 20 wt% of methyl methacrylate monomer, 0.1 wt% of dibenzoyl peroxide and 1M lithium hexafluorophosphate, wherein EC / DMC=1:1 (volume ratio). The abo...

Embodiment 2

[0045] Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with a content of 5wt% is dissolved in a mixture of 83wt% acetone, 10wt% ethanol and 2wt% acetylene black (the average particle size of the crystal particles is 0.02 μm) After stirring for one hour, it is coated on a polyethylene film (PE) with a thickness of 16 μm and a porosity of 40%, and cast into a film. The thickness of the film is 12 μm, and the porosity is 38% after drying. The first porous polymer film was 86 nm. Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with a content of 6wt% was dissolved in 81wt% methyl ethyl ketone, 12wt% toluene and 1wt% acetylene black (the average particle size of the crystal particles was 0.01 μm) In the mixed solution, after stirring for one hour, coat the surface of the first porous polymer membrane prepared above, cast it into a membrane, the thickness of the membrane is 8 μm, and dry to obtain the first porous polymer membrane with a porosity of 50% and an average p...

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