CN108242560B

CN108242560B - Zinc-based dual-ion battery and preparation method thereof

Info

Publication number: CN108242560B
Application number: CN201711426982.0A
Authority: CN
Inventors: 唐永炳; 季必发; 张帆
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2017-12-26
Filing date: 2017-12-26
Publication date: 2021-04-20
Anticipated expiration: 2037-12-26
Also published as: CN108242560A

Abstract

The invention provides a zinc-based dual-ion battery, which comprises a positive electrode, a negative electrode, a diaphragm arranged between the positive electrode and the negative electrode, and electrolyte, wherein the electrolyte is non-aqueous zinc salt electrolyte; the positive electrode comprises a positive electrode current collector and a positive electrode material combined on the surface of the positive electrode current collector, wherein the positive electrode material contains a positive electrode active material, and the positive electrode active material is a layered material capable of allowing anions forming zinc salt to be reversibly embedded and extracted; the negative electrode is a metal foil which is used as a negative electrode current collector and a negative electrode active material at the same time, and the metal foil is a metal foil which can be used for reversible deposition and dissolution of zinc ions or can be used for reversible alloying reaction with zinc.

Description

Zinc-based dual-ion battery and preparation method thereof

Technical Field

The invention belongs to the technical field of new energy, and particularly relates to a zinc-based dual-ion battery and a preparation method thereof.

Background

A secondary battery is also called a rechargeable battery, and is a battery that can be repeatedly charged and discharged and used many times. Compared with a primary battery which can not be repeatedly used, the secondary battery has the advantages of low use cost and small environmental pollution. The main secondary battery technologies at present are lead-acid batteries, nickel-chromium batteries, nickel-hydrogen batteries and lithium ion batteries. Among them, lithium ion batteries are most widely used. In recent years, lithium ion batteries are widely applied to the fields of portable electronic devices and power automobiles, so that the demand of lithium is increased explosively, the global storage of lithium is very limited and is not uniformly distributed, the price of raw materials is rapidly increased, and the development of the corresponding energy storage field is severely restricted. The zinc ion battery is a novel secondary battery developed in recent years, has the advantages of high energy density, high power density, efficient and safe charging and discharging processes, nontoxic and cheap battery materials, simple preparation process and the like, has high application value and development prospect in the fields of large-scale energy storage and the like, and has attracted more and more attention in recent years. The working principle of the zinc ion battery is similar to that of the lithium ion battery, and in the zinc ion battery, zinc ions are rapidly and reversibly deposited and dissolved on the surface of a metal zinc cathode and are reversibly embedded or removed from a positive electrode material. A common zinc ion battery uses manganese dioxide, vanadium pentoxide, metal ferricyanide, and the like as positive electrode active materials, metal zinc as a negative electrode active material, and an aqueous solvent containing zinc salt as an electrolyte.

At present, common zinc ion batteries are basically based on aqueous electrolyte, and on one hand, in the aqueous electrolyte, the potential of different areas is different due to uneven distribution of the surface of a zinc electrode, so that an infinite number of corrosion micro-batteries with combined action are formed. Corrosion can cause cell self-discharge, thereby reducing zinc utilization and cell capacity. In addition, in the sealed environment of the battery, hydrogen generated in the corrosion process causes the internal pressure of the battery to increase, and when the internal pressure is increased to a certain degree, the leakage of electrolyte and even explosion can be caused, and safety accidents can be caused. On the other hand, during the discharge process of the water-based zinc ion battery, the insoluble ZnO or Zn (OH) is directly generated₂When the anode product covers the surface of the electrode, the normal dissolution of zinc is influenced, the reaction surface area of the zinc electrode is reduced, and the electrode is inactivated and changed into a passive state. The specific surface area of the electrode is reduced, and relatively speaking, the electrode density is increased, so that the polarization of the battery is caused, and the cycle performance of the battery is reduced. In addition, the anode materials of the zinc ion batteries reported at present are very limited, the cycle performance is poor, and the preparation process is complex.

Disclosure of Invention

The invention aims to provide a zinc-based double-ion battery and a preparation method thereof, and aims to solve the problems that the electrochemical performance of the battery is reduced and potential safety hazards exist due to self-corrosion and passivation of the existing aqueous lithium-ion battery.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a zinc-based dual ion battery including a positive electrode and a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte, wherein,

the electrolyte is a non-aqueous zinc salt electrolyte;

the positive electrode comprises a positive electrode current collector and a positive electrode material combined on the surface of the positive electrode current collector, wherein the positive electrode material contains a positive electrode active material, and the positive electrode active material is a layered material capable of allowing anions forming zinc salt to be reversibly embedded and extracted;

the negative electrode is a metal foil which is used as a negative electrode current collector and a negative electrode active material at the same time, and the metal foil is a metal foil which can be used for reversible deposition and dissolution of zinc ions or can be used for reversible alloying reaction with zinc.

Preferably, the zinc salt electrolyte is a mixed solution of zinc salt and an organic solvent and/or an ionic liquid.

Preferably, the positive electrode active material is at least one selected from the group consisting of carbon materials, sulfides, nitrides, oxides, and carbides.

Preferably, the carbon material is selected from at least one of mesocarbon microbeads graphite, natural graphite, expanded graphite, artificial graphite, glassy carbon, carbon-carbon composite material, carbon fiber, hard carbon, porous carbon, highly oriented graphite, three-dimensional graphite, carbon black, carbon nanotubes and graphene.

Preferably, the sulfide is at least one selected from molybdenum disulfide, tungsten disulfide, vanadium disulfide, titanium disulfide, iron disulfide, ferrous sulfide, nickel sulfide, zinc sulfide, cobalt sulfide, and manganese sulfide.

Preferably, the nitride is selected from at least one of hexagonal boron nitride and carbon-doped hexagonal boron nitride.

Preferably, the oxide is at least one selected from molybdenum trioxide, tungsten trioxide, vanadium pentoxide, vanadium dioxide, titanium dioxide, zinc oxide, copper oxide, nickel oxide and manganese oxide.

Preferably, the carbide is selected from at least one of titanium carbide, tantalum carbide, molybdenum carbide and silicon carbide.

Preferably, the metal foil is selected from one of zinc, nickel, titanium, antimony, lithium, potassium, copper, aluminum and magnesium.

Preferably, the metal foil is an alloy formed by at least two of zinc, nickel, titanium, antimony, lithium, potassium, copper, aluminum and magnesium.

Preferably, the metal foil is a composite material formed by at least two of zinc, nickel, titanium, antimony, lithium, potassium, copper, aluminum and magnesium.

Preferably, the organic solvent is at least one selected from esters, sulfones, ethers, nitriles and olefin organic solvents.

Preferably, the ionic liquid is at least one selected from imidazole, piperidine, pyrrole, quaternary ammonium or amide ionic liquids.

Preferably, the organic solvent is selected from at least one of propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, methyl formate, methyl acetate, N-dimethylacetamide, fluoroethylene carbonate, methyl propionate, ethyl acetate, γ -butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1, 3-dioxolane, 4-methyl-1, 3-dioxolane, dimethoxymethane, 1, 2-dimethoxypropane, triethylene glycol dimethyl ether, dimethyl sulfone, dimethyl ether, vinyl sulfite, propylene sulfite, dimethyl sulfite or diethyl sulfite, or crown ether (12-crown-4).

Preferably, the ionic liquid is selected from the group consisting of 1-ethyl-3-methylimidazole-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroborate, 1-ethyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methylimidazole-tetrafluoroborate, 1-propyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl-1-methylimidazole-tetrafluoroborate, 1-butyl-1-methylimidazole-bistrifluoromethylsulfonyl imide salt, and mixtures thereof, At least one of N-butyl-N-methylpyrrolidine-bistrifluoromethylsulfonyl imide salt, 1-butyl-1-methylpyrrolidine-bistrifluoromethylsulfonyl imide salt, N-methyl-N-propylpyrrolidine-bistrifluoromethylsulfonyl imide salt, N-methyl, propylpiperidine-bistrifluoromethylsulfonyl imide salt, or N-methylbutylpiperidine-bistrifluoromethylsulfonyl imide salt.

Preferably, the zinc salt electrolyte further contains an additive, and the mass percentage of the additive in the zinc salt electrolyte is 0.1-20%.

Preferably, the concentration of the zinc salt electrolyte is 0.1-10 mol/L.

The invention also provides a preparation method of the zinc-based dual-ion battery, which comprises the following steps:

providing a positive electrode, a negative electrode, zinc salt electrolyte and a diaphragm of the zinc-based double-ion battery according to the composition of the zinc-based double-ion battery;

and sequentially stacking and winding the positive electrode, the diaphragm and the negative electrode to form a battery core, injecting liquid, packaging and preparing the zinc-based dual-ion battery.

The zinc-based dual-ion battery provided by the invention has the following advantages:

firstly, the zinc-based dual-ion battery provided by the invention directly takes a metal foil which can reversibly deposit and dissolve zinc or can reversibly alloy with zinc alloy as a negative active material of the battery as a negative active material, takes a layered material which can be used for inserting and extracting anions as a positive active material, and takes zinc salt as electrolyte. The zinc ions in the zinc salt are adsorbed and desorbed on the cathode active material, and meanwhile, the anions in the zinc salt are embedded and desorbed on the anode active material, so that the energy storage is realized together. The battery capacity and the cycling stability are improved through the combined action of zinc salt double ions in the electrolyte, and the zinc-based double-ion battery is endowed with excellent electrochemical performance.

Secondly, compared with the traditional lithium ion battery, the zinc-based dual-ion battery cathode material adopts the metal foil which can reversibly deposit and dissolve zinc or can reversibly perform alloying reaction with zinc as the battery cathode active material and the cathode current collector. During charging, zinc ions are deposited on the negative electrode or form an alloy with the metal of the negative electrode; during discharging, zinc ions are dissolved or dealloyed from the negative electrode, so that the production flow is simplified, the volume and the quality of the battery are reduced, the production cost is saved, and the energy density of the battery is obviously improved.

Thirdly, the anode material of the zinc-based dual-ion battery adopts a layered material capable of inserting and extracting anions as an anode active material, a large amount of zinc salt anions in the electrolyte are reversibly inserted and extracted in the layered material, and specifically, the anions are inserted into lattices of the anode active material from the electrolyte during charging; during discharging, anions are removed from the positive active material, so that energy storage is realized through intercalation reaction, and the battery capacity is improved. In addition, the voltage of the anion intercalation process is higher, thereby further improving the energy density of the battery.

Fourthly, the zinc-based dual-ion battery is a non-aqueous zinc salt electrolyte, can effectively overcome the defects of self-corrosion and passivation of the existing aqueous zinc ion battery, and can improve the safety performance of the zinc ion battery.

Fifth, the zinc-based dual-ion battery of the invention uses zinc ions with low cost and abundant resources as an energy storage medium, and the zinc-based dual-ion battery uses zinc salt to replace lithium salt, so that the application of the zinc-based dual-ion battery is not restricted by lithium resources, and the battery can be developed greatly. The anode and cathode materials are simple, easy to obtain, environment-friendly and safe, the production process is simple, the cost is low, the selectable range of the anode material of the existing zinc ion battery is greatly expanded, and the cycle life of the zinc ion battery is remarkably prolonged. In addition, the zinc salt is far less expensive than the lithium salt, so that the production cost of the zinc-based dual-ion battery is remarkably reduced.

The preparation method of the zinc-based dual-ion battery provided by the invention is only required to wind the anode, the cathode and the diaphragm and then perform liquid injection and assembly, and the preparation method is simple.

Drawings

Fig. 1 is a schematic structural diagram of a zinc-based dual-ion battery provided by an embodiment of the invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

The embodiment of the invention provides a zinc-based dual-ion battery, which comprises a positive electrode, a negative electrode, a diaphragm arranged between the positive electrode and the negative electrode, and electrolyte, wherein,

the electrolyte is a non-aqueous zinc salt electrolyte;

The zinc-based dual-ion battery provided by the embodiment of the invention has the following advantages:

firstly, in the zinc-based dual-ion battery provided by the embodiment of the invention, a metal foil capable of reversibly depositing and dissolving zinc or reversibly dealloying with a zinc alloy is directly used as a battery negative electrode active material as a negative electrode active material, a layered material capable of inserting and extracting anions is used as a positive electrode active material, and zinc salt is used as an electrolyte. The zinc ions in the zinc salt are adsorbed and desorbed on the cathode active material, and meanwhile, the anions in the zinc salt are embedded and desorbed on the anode active material, so that the energy storage is realized together. The battery capacity and the cycling stability are improved through the combined action of zinc salt double ions in the electrolyte, and the zinc-based double-ion battery is endowed with excellent electrochemical performance.

Secondly, compared with the traditional lithium ion battery, the zinc-based dual-ion battery cathode material provided by the embodiment of the invention adopts the metal foil capable of reversibly depositing and dissolving zinc or reversibly alloying with zinc as the battery cathode active material and the cathode current collector. During charging, zinc ions are deposited on the negative electrode or form an alloy with the metal of the negative electrode; during discharging, zinc ions are dissolved or dealloyed from the negative electrode, so that the production flow is simplified, the volume and the quality of the battery are reduced, the production cost is saved, and the energy density of the battery is obviously improved.

Thirdly, the anode material of the zinc-based dual-ion battery in the embodiment of the invention adopts a layered material capable of inserting and extracting anions as an anode active material, a large amount of zinc salt anions in the electrolyte are reversibly inserted and extracted in the layered material, and specifically, during charging, the anions are inserted into crystal lattices of the anode active material from the electrolyte; during discharging, anions are removed from the positive active material, so that energy storage is realized through intercalation reaction, and the battery capacity is improved. In addition, the voltage of the anion intercalation process is higher, thereby further improving the energy density of the battery.

Fourthly, according to the zinc-based dual-ion battery provided by the embodiment of the invention, the electrolyte is a non-aqueous zinc salt electrolyte, so that the defects of self-corrosion and passivation of the existing aqueous zinc ion battery can be effectively overcome, and the safety performance of the zinc ion battery can be improved.

Fifth, the zinc-based dual-ion battery of the embodiment of the invention uses zinc ions with low cost and rich resources as an energy storage medium, and the zinc-based dual-ion battery uses zinc salts to replace lithium salts, so that the application of the zinc-based dual-ion battery is not limited by lithium resources, and the battery can be developed greatly. The anode and cathode materials are simple, easy to obtain, environment-friendly and safe, the production process is simple, the cost is low, the selectable range of the anode material of the existing zinc ion battery is greatly expanded, and the cycle life of the zinc ion battery is remarkably prolonged. In addition, the zinc salt is far less expensive than the lithium salt, so that the production cost of the zinc-based dual-ion battery is remarkably reduced.

With respect to the positive electrode

The positive electrode comprises a positive electrode current collector and a positive electrode material combined on the surface of the positive electrode current collector, wherein the positive electrode material contains a positive electrode active material, and the positive electrode active material is a layered material capable of allowing anions forming zinc salts to be reversibly inserted and extracted.

The embodiment of the invention adopts the layered material which can allow the anions forming the zinc salt to be reversibly inserted and extracted as the positive active material, so that a large amount of anions of the zinc salt electrolyte in the zinc salt electrolyte can be reversibly inserted and extracted in the positive active material, thereby improving the battery capacity. During charging, anions are inserted into crystal lattices of the positive electrode material from the electrolyte; during discharging, anions are removed from the anode material, and energy storage is realized through intercalation reaction.

Preferably, the positive electrode active material is at least one selected from the group consisting of carbon materials, sulfides, nitrides, oxides, and carbides. Preferably, the positive active materials all have a layered structure, can provide sites for anion intercalation, and provide higher capacity.

Particularly preferably, the carbon material is selected from at least one of mesocarbon microbeads graphite, natural graphite, expanded graphite, artificial graphite, glassy carbon, carbon-carbon composite material, carbon fiber, hard carbon, porous carbon, highly oriented graphite, three-dimensional graphite, carbon black, carbon nanotubes and graphene, but is not limited thereto. Particularly preferably, the sulfide is selected from at least one of molybdenum disulfide, tungsten disulfide, vanadium disulfide, titanium disulfide, iron disulfide, ferrous sulfide, nickel sulfide, zinc sulfide, cobalt sulfide, and manganese sulfide, but is not limited thereto. Particularly preferably, the nitride is selected from at least one of hexagonal boron nitride and carbon-doped hexagonal boron nitride, but is not limited thereto. Specifically, the oxide is selected from at least one of molybdenum trioxide, tungsten trioxide, vanadium pentoxide, vanadium dioxide, titanium dioxide, zinc oxide, copper oxide, nickel oxide, and manganese oxide, but is not limited thereto. Particularly preferably, the carbide is selected from at least one of titanium carbide, tantalum carbide, molybdenum carbide and silicon carbide, but is not limited thereto.

The preferable positive electrode active material has a proper layered structure and a proper interlayer distance, and is beneficial to the reversible insertion and extraction of anions of the zinc salt electrolyte. Compared with other layered materials, the carbon material is cheap and easy to obtain, so the positive electrode active material in the embodiment of the invention is preferably the carbon material, and the expanded graphite in the carbon material has larger interlayer spacing, so the anion intercalation barrier is lower, and particularly preferably the expanded graphite.

In the embodiment of the invention, the positive electrode material contains an oil conductive agent and a binder in addition to the positive electrode active material. And the positive electrode material comprises the following components in percentage by weight, based on the total weight of the positive electrode material as 100 percent:

60-95% of positive active material;

2-30% of a conductive agent;

3-10% of a binder.

In the positive electrode material, the content of the positive electrode active material, the conductive agent and the binder meets the requirements, and the obtained positive electrode material can be endowed with better comprehensive performance, so that the function of the positive electrode material in a battery is well exerted.

Specifically, the selection and preferred cases of the positive electrode active material are as described above. The weight percentage of the positive active material can be 60%, 70%, 75%, 80%, 85%, 90% and 95%, and the specific amount can be selected according to the specific type and concentration of the zinc salt electrolyte in the zinc-based dual-ion battery.

The conductive agent can be selected from conductive agent components commonly used in battery positive electrode materials, including but not limited to at least one of conductive carbon black, conductive carbon spheres, conductive graphite, carbon nanotubes, carbon fibers or graphene, and embodiments of the present invention are not limited strictly. The weight percentage of the conductive agent can be 2%, 5%, 10%, 15%, 20%, 25% and 30%, and the specific dosage can be selected according to the specific type of the positive active material in the zinc-based double-ion battery positive material.

The binder may be selected from binder components commonly used for battery positive electrode materials, including but not limited to at least one of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, SBR rubber, and polyolefins (polybutadiene, polyvinyl chloride, polyisoprene, etc.), and embodiments of the present invention are not limited thereto. The weight percentage of the binder can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, and the specific amount can be selected according to the specific types of the positive active material and the conductive agent in the zinc-based bipolar battery positive material.

In the embodiment of the invention, the positive electrode material is combined on the surface of the positive electrode current collector. The positive current collector is a metal conductive material, and the conductive material includes, but is not limited to, one metal of aluminum, copper, tin, zinc, lead, antimony, cadmium, gold, bismuth and germanium, or an alloy containing at least any one of the foregoing metals, or a composite containing at least any one of the foregoing metals.

As a particularly preferred embodiment, the positive electrode in the zinc-based dual-ion battery is selected to be carbon-coated aluminum foil, i.e. the positive electrode current collector is preferably aluminum, and the positive electrode active material is preferably a carbon material.

With respect to the negative electrode

In the embodiment of the invention, the negative electrode is a metal foil, and the metal foil has good conductivity and can be used for reversible deposition dissolution or alloy dealloying of zinc ions, so that the metal foil can be used as a negative electrode current collector and a negative electrode active material at the same time, and the metal foil can be used for reversible deposition dissolution of zinc ions or can be used for reversible alloying reaction with zinc.

Preferably, the metal foil is selected from one of zinc, nickel, titanium, antimony, lithium, potassium, copper, aluminum and magnesium; or the metal foil is an alloy formed by at least two of zinc, nickel, titanium, antimony, lithium, potassium, copper, aluminum and magnesium; or the metal foil is a composite material formed by at least two of zinc, nickel, titanium, antimony, lithium, potassium, copper, aluminum and magnesium. The material has good conductivity, and can be used for reversible deposition and dissolution of zinc ions or alloy dealloying.

Particularly preferably, the metal foil is zinc.

About electrolyte

The electrolyte is a non-aqueous zinc salt electrolyte, namely the electrolyte is a non-aqueous solvent electrolyte, so that the defects of self-corrosion and passivation of the conventional aqueous zinc ion battery can be effectively overcome, and the safety performance of the zinc ion battery can be improved.

The zinc salt with abundant reserves and low price is used as the electrolyte of the zinc-based dual-ion battery, so that the cost of the battery can be reduced, and the battery has better safety performance.

Specifically, the zinc salt may be an organic zinc salt or an inorganic zinc salt, and the embodiment of the present invention is not limited strictly as long as the zinc salt can be dissociated into a zinc ion and an anion.

In a preferred embodiment, the electrolyte zinc salt is one or more of zinc chloride, zinc nitrate, zinc acetate, zinc fluoride, zinc citrate, zinc bromide, zinc oxalate, zinc aluminate, zinc dichromate, zinc perchlorate, zinc bistrifluoromethanesulfonylimide, zinc tetrafluoroborate, diethylzinc, bis (pentamethylcyclopentadienylzinc), zinc trifluoromethanesulfonate, and related complexes of zinc. Most preferably, the electrolyte zinc salt is zinc bis (trifluoromethanesulfonyl) imide.

Preferably, the concentration of the zinc salt electrolyte is 0.1 to 10mol/L, more preferably 0.5 to 1mol/L, for example 0.5mol/L, 0.7mol/L, or 1 mol/L. The concentration of the zinc salt electrolyte affects the ion concentration, which affects the ion transport properties of the electrolyte. If the concentration of zinc salt in the electrolyte is too low, zinc ions and anions are too few, the ion transmission performance is poor, and the conductivity is low; if the concentration of zinc salt in the electrolyte is too high and there are too many zinc ions and anions, the viscosity of the electrolyte and the degree of ionic association will also increase with increasing concentration of zinc salt, which in turn will decrease the conductivity.

In the embodiment of the present invention, the solvent of the electrolyte is a non-aqueous solvent, and is not particularly limited as long as the solvent can dissociate the electrolyte zinc salt into zinc ions and anions, and the cations and the anions can freely migrate.

In a preferred embodiment, the solvent in the electrolyte is an organic solvent and/or an ionic liquid, that is, the zinc salt electrolyte is a mixed solution of a zinc salt and an organic solvent and/or an ionic liquid, and the solvent is used for dissociating the zinc salt and serves as a zinc ion and anion transmission medium.

Preferably, the organic solvent is at least one selected from esters, sulfones, ethers, nitriles and olefin organic solvents, particularly preferably, the organic solvent is at least one selected from propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, methyl formate, methyl acetate, N-dimethylacetamide, fluoroethylene carbonate, methyl propionate, ethyl acetate, gamma-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1, 3-dioxolane, 4-methyl-1, 3-dioxolane, dimethoxymethane, 1, 2-dimethoxypropane, triethylene glycol dimethyl ether, dimethyl sulfone, dimethyl ether, ethylene sulfite, propylene sulfite, dimethyl sulfite or diethyl sulfite or crown ether (12-crown-4). Preferred organic solvents are capable of dissociating zinc salts well and efficiently transporting zinc ions and anions.

The ionic liquid has a higher voltage window, and can improve the electrode energy density of the double-ion battery. The ionic liquid is difficult to volatilize and is not flammable, so that the dual-ion battery can keep long service life and high safety, and can operate at high temperature. Preferably, the ionic liquid is at least one selected from imidazole, piperidine, pyrrole, quaternary ammonium or amide ionic liquids. Particularly preferably, the ionic liquid is selected from the group consisting of 1-ethyl-3-methylimidazole-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroborate, 1-ethyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methylimidazole-tetrafluoroborate, 1-propyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl-1-methylimidazole-tetrafluoroborate, 1-butyl-1-methylimidazole-bistrifluoromethylsulfonyl imide salt, and mixtures thereof, At least one of N-butyl-N-methylpyrrolidine-bistrifluoromethylsulfonyl imide salt, 1-butyl-1-methylpyrrolidine-bistrifluoromethylsulfonyl imide salt, N-methyl-N-propylpyrrolidine-bistrifluoromethylsulfonyl imide salt, N-methyl, propylpiperidine-bistrifluoromethylsulfonyl imide salt, or N-methylbutylpiperidine-bistrifluoromethylsulfonyl imide salt.

More preferably, the zinc salt electrolyte further contains an additive, and the mass percentage of the additive in the zinc salt electrolyte is 0.1-20%. One or more additives are added into the electrolyte to further improve one or more performances of the zinc-based dual-ion battery, the selection of the additives is not strictly limited, and the conventional electrolyte additives can be adopted. Specifically, the mass fraction of the additive in the total mass of the electrolyte is 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%.

Classified from the role of additives, including film forming additives (e.g., carbon dioxide, sulfur dioxide, lithium carbonate, carbonates, thio organic solvents, halogenated organic film forming additives, etc.); overcharge protection additives (having redox couple: ortho-and para-dimethoxy substituted benzenes, polymerization to increase internal resistance, blocking charges, such as biphenyl, cyclohexylbenzene, etc.), stabilizers, additives to improve high and low temperature performance, conductive additives or flame retardant additives (organophosphates, organofluoro compounds, haloalkyl phosphates), etc. The additives may be used singly or in combination of two or more kinds.

Preferably, the additive is at least one selected from organic additives such as esters, sulfones, ethers, nitriles and olefins, and inorganic additives such as carbon dioxide, sulfur dioxide and lithium carbonate.

Specifically preferred, the additives include, but are not limited to, fluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate, 1, 3-propanesultone, 1, 4-butanesultone, vinyl sulfate, propylene sulfate, ethylene sulfate, vinyl sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, ethylene sulfite, methyl chloroformate, dimethyl sulfoxide, anisole, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown ether 18-crown-6, 4-fluorophenylmethyl ether, fluorinated chain ether, vinyl difluoromethyl carbonate, vinyl trifluoromethylcarbonate, vinyl chlorocarbonate, vinyl bromocarbonate, trifluoroethylphosphonic acid, bromobutyrolactone, fluoroacetoethane, phosphate, phosphite, Phosphazene, ethanolamine, carbonized dimethylamine, cyclobutyl sulfone, 1, 3-dioxolane, acetonitrile, long-chain olefin, aluminum oxide, magnesium oxide, barium oxide, sodium carbonate, calcium carbonate, carbon dioxide, sulfur dioxide, and lithium carbonate.

About a diaphragm

In the embodiment of the invention, the diaphragm is arranged between the positive electrode and the negative electrode and is used for separating the positive electrode from the negative electrode and simultaneously carrying electrolyte for the back-and-forth transmission of zinc ions in the electrolyte and anions of a zinc salt electrolyte.

Preferably, the separator includes, but is not limited to, an insulating porous polymer film or an inorganic porous film. Particularly preferably, the separator includes, but is not limited to, one or more of a porous polypropylene film, a porous polyethylene film, a porous composite polymer film, a non-woven fabric, a glass fiber paper or a porous ceramic separator.

Others

Further preferably, the zinc-based dual ion battery of the invention further comprises a housing or an outer package for packaging. The case or the outer package may be appropriately selected from any outer package without limitation as long as it is stable to the electrolyte and has sufficient sealing performance.

In addition, the zinc-based dual-ion battery provided by the embodiment of the invention is not limited to a button type, and can be designed into a flat plate type, a cylindrical type or a laminated type according to core components.

The structural schematic diagram of the zinc-based dual-ion battery in the embodiment of the invention is shown in fig. 1, wherein a battery negative electrode (1), an electrolyte (2), a diaphragm (3), a battery positive electrode active material (4) and a positive electrode current collector (5), wherein the electrolyte (2) is filled in all spaces between the positive electrode and the negative electrode (the electrolyte (2) shown in fig. 1 is only used as a schematic diagram). The zinc-based dual-ion battery provided by the embodiment of the invention can be prepared by the following method.

and sequentially stacking and winding the positive electrode, the diaphragm and the negative electrode to form a battery core, injecting liquid, and packaging to prepare the zinc-based dual-ion battery.

The preparation method of the zinc-based dual-ion battery provided by the embodiment of the invention only needs to wind the anode, the cathode and the diaphragm and then perform liquid injection and assembly, and the preparation method is simple.

Specifically, the negative electrode can be obtained by cutting the metal foil into a desired size, and then performing surface cleaning and drying treatment. The negative foil serves as a negative current collector and a negative active material at the same time.

The preparation method of the positive electrode comprises the following steps: firstly, providing a positive electrode active material, a conductive agent and a binder, mixing the positive electrode active material, the conductive agent and the binder to prepare slurry, coating the slurry on the surface of a positive electrode current collector, and cutting pieces after drying treatment to obtain the positive electrode with the required size.

The preparation method of the electrolyte comprises the following steps: dissolving zinc salt electrolyte in organic solvent and/or ionic liquid, and fully stirring and mixing to obtain the electrolyte.

The separator may be prepared by cutting a porous polymer film, an inorganic porous film, or an organic/inorganic composite separator into a desired size.

During preparation, the prepared negative electrode, the diaphragm and the positive electrode are sequentially and tightly stacked in an inert gas or anhydrous oxygen-free environment, electrolyte is dripped to completely soak the diaphragm, and then the diaphragm is sealed into a shell to finish the assembly of the zinc-based dual-ion battery.

The following description will be given with reference to specific examples.

Example 1

A zinc-based dual-ion battery comprises a negative electrode, a diaphragm, electrolyte and a positive electrode, and the preparation method comprises the following steps:

preparing a negative electrode: taking a zinc foil with the thickness of 0.02mm, cutting the zinc foil into a wafer with the diameter of 12mm, cleaning the surface of the tin foil by using ethanol, and airing the tin foil to be used as a negative current collector for later use.

Preparing a diaphragm: the glass fiber diaphragm is cut into a circular piece with the diameter of 16mm, and the circular piece is dried to be used as the diaphragm for standby.

Preparing an electrolyte: 3.19g of bis (trifluoromethanesulfonyl) imide zinc is weighed and added into 5mL of N-butyl-N-methylpyrrolidine bis (trifluoromethanesulfonyl) imide salt, the mixture is stirred until the bis (trifluoromethanesulfonyl) imide zinc is completely dissolved, and the mixture is used as electrolyte for standby after being fully stirred uniformly (the concentration of the electrolyte is 1M).

Preparing a positive electrode: adding 0.8g of expanded graphite, 0.1g of carbon black and 0.1g of polyvinylidene fluoride into 2mL of nitrogen methyl pyrrolidone solution, and fully grinding to obtain uniform slurry; and then uniformly coating the slurry on the surface of the copper foil and performing vacuum drying. Cutting the dried electrode slice into a wafer with the diameter of 10mm, and compacting the wafer to be used as a positive electrode for standby.

Assembling: and in a glove box protected by inert gas, tightly stacking the prepared positive electrode, the diaphragm and the negative electrode in sequence, dripping electrolyte to completely soak the diaphragm, and packaging the stacked part into a button type shell to finish the assembly of the zinc-based double-ion battery.

Example 2

A zinc-based dual ion battery is provided, wherein the negative electrode material active substance adopts metallic nickel, and the rest is the same as the embodiment 1.

Example 3

A zinc-based dual ion battery is provided, wherein the active material of the negative electrode material adopts metallic titanium, and the rest is the same as the embodiment 1.

Example 4

A zinc-based bi-ion battery is provided, wherein metallic antimony is adopted as a negative electrode material active substance, and the rest is the same as the embodiment 1.

Example 5

A zinc-based dual ion battery in which metallic lithium is used as a negative electrode material active material, the other is the same as in example 1.

Example 6

A zinc-based dual ion battery is provided, wherein the active material of the negative electrode adopts copper-zinc alloy, and the rest is the same as the embodiment 1.

Example 7

A zinc-based dual ion battery, in which a nickel-carbon composite material is used as a negative electrode material active material, is otherwise the same as in example 1.

Example 8

A zinc-based dual-ion battery is provided, wherein the active substance of the anode material is mesocarbon microbead graphite, and the rest is the same as that of the battery in the embodiment 1.

Example 9

A zinc-based dual ion battery in which the positive electrode material active material is hard carbon, the rest being the same as in example 1.

Example 10

A zinc-based dual ion battery in which the positive electrode material active material is three-dimensional graphite, the other is the same as in example 1.

Example 11

A zinc-based dual ion battery in which the positive electrode material active material is single-walled carbon nanotubes, the rest being the same as in example 1.

Example 12

A zinc-based dual-ion battery is disclosed, wherein the active substance of the positive electrode material adopts multi-wall carbon nano-tubes, and the rest is the same as the embodiment 1.

Example 13

A zinc-based dual ion battery is provided, wherein the conductive agent used for the positive electrode is Super P, and the rest is the same as the embodiment 1.

Example 14

A zinc-based dual ion battery is provided, wherein the conductive agent used in the positive electrode is carbon nano-tube, and the rest is the same as the embodiment 1.

Example 15

A zinc-based dual-ion battery is provided, wherein the conductive agent used for the positive electrode is graphene, and the rest is the same as that in the embodiment 1.

Example 16

A zinc-based bi-ion battery is provided, wherein the binder used in the positive electrode is polyvinylidene fluoride, and the rest is the same as that in example 1.

Example 17

A zinc-based bi-ion battery is provided, wherein the binder used in the positive electrode is carboxymethyl cellulose, and the rest is the same as that in example 1.

Example 18

A zinc-based dual ion battery is provided, wherein the binder used in the positive electrode is SBR rubber, and the rest is the same as the embodiment 1.

Example 19

A zinc-based dual-ion battery is disclosed, wherein the zinc salt used in the electrolyte is zinc trifluoromethanesulfonate, and the rest is the same as that in example 1.

Example 20

A zinc-based dual-ion battery is disclosed, wherein the zinc salt used in the electrolyte is zinc perchlorate, and the rest is the same as that in the example 1.

Example 21

A zinc-based dual-ion battery is disclosed, wherein the solvent used in the electrolyte is N-methyl, propyl piperidine-bis (trifluoromethyl) sulfonyl imide salt, and the rest is the same as the example 1.

Example 22

A zinc-based dual ion battery, wherein the electrolyte uses 1-ethyl-3-methylimidazole-hexafluorophosphate as a solvent, and the rest is the same as in example 1.

Example 23

A zinc-based dual-ion battery is disclosed, wherein the electrolyte uses ethylene carbonate and ethyl methyl carbonate (volume ratio 1:1) as solvent, and the rest is the same as that of the embodiment 1.

Example 24

A zinc-based dual ion battery is provided, wherein the electrolyte uses ethylene carbonate and dimethyl carbonate (volume ratio 1:1) as the solvent, and the rest is the same as the example 1.

Example 25

A zinc-based dual ion battery is provided, wherein the electrolyte uses ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate (volume ratio 1:1:1) as solvent, and the other steps are the same as the example 1.

Example 26

A zinc-based dual ion battery is provided, wherein the electrolyte uses ethylene carbonate and diethyl carbonate (volume ratio 1:1) as solvent, and the rest is the same as the example 1.

Example 27

A zinc-based dual ion battery having an electrolyte concentration of 0.4M, otherwise the same as in example 1.

Example 28

A zinc-based dual ion battery having an electrolyte concentration of 0.6M, otherwise the same as in example 1.

Example 29

A zinc-based dual ion battery having an electrolyte concentration of 0.8M, otherwise the same as in example 1.

Example 30

A zinc-based dual ion battery is disclosed, wherein a porous polypropylene film is used as a separator, and the rest is the same as that of the battery in example 2.

Example 31

A zinc-based dual ion battery is provided, wherein a porous polyethylene film is adopted as a separator, and the rest is the same as that of the embodiment 2.

Example 32

A zinc-based dual ion battery is provided, in which a porous ceramic film is used as a separator, and the rest is the same as that of example 2.

The zinc-based dual-ion battery of the embodiment 1-32 and the battery of the comparative example 1 are tested for electrochemical performance and safety performance, the electrochemical performance test comprises specific capacity and cycle times, a conventional battery testing method is adopted, and the specific capacity is the specific discharge capacity of the battery under the charging and discharging condition of 1C; the cycle times are the corresponding cycle times when the discharge specific capacity reaches 90% under the condition of 1C. The safety performance test adopts a needle punching test, the battery is charged to a rated voltage by constant current, a high-temperature resistant steel needle with the diameter of phi 3-8 mm penetrates through the battery in a direction perpendicular to a battery plate (the steel needle stays in the battery) at the speed of 10-40 mm/s, and the test is carried out under the condition of sufficient environmental protection. The test results are shown in table 1.

TABLE 1

It can be seen from table 1 that the zinc-based dual-ion battery of the invention, which uses the metallic zinc capable of reversibly depositing and dissolving zinc as the negative electrode and the expanded graphite capable of reversibly inserting and extracting as the positive electrode active material, has high specific capacity, long cycle life and good safety performance.

Compared with the embodiment 1, the embodiments 2 to 7 have different active material materials used for the negative electrode, and different electrochemical properties of the obtained zinc-based dual-ion battery, wherein the specific capacity of the zinc-based dual-ion battery obtained by adopting the metal zinc as the negative electrode active material is higher than that of the zinc-based dual-ion battery obtained by adopting other metals, alloys or composite materials as the negative electrode active material, and the cyclicity is good.

Examples 8-12 compared to example 1, the electrochemical performance of the zinc-based bipolar battery was obtained using a different carbon material for the positive electrode active material. The zinc-based double-ion battery obtained by adopting the expanded graphite as the positive active substance has the best electrochemical performance.

Compared with the example 1, the types of the conductive agents used in the positive and negative electrode materials of the examples 13 to 15 are different, and the types of the binders used in the positive and negative electrode materials of the examples 16 to 18 are different from the example 1, so that the electrochemical performance of the obtained zinc-based dual-ion battery is not greatly different, and the influence of the conductive agents and the types of the binders added in the positive and negative electrode materials on the electrochemical performance of the whole zinc-based dual-ion battery is not large.

Compared with the zinc salt used in the electrolyte in the embodiment 1, the zinc salt used in the electrolyte in the embodiments 19-21 has a larger difference in the electrochemical performance of the zinc-based dual-ion battery.

In examples 22 to 26, compared with example 1, the solvents used in the electrolyte are different, and the obtained zinc-based dual-ion battery has different electrochemical performances, and it can be seen that the electrolyte solvent has a certain influence on the electrochemical performances of the zinc-based dual-ion battery.

In examples 27 to 29, compared with example 1, the electrolyte concentration is different, the electrochemical performance of the obtained zinc-based dual-ion battery is different, and when the electrolyte is 1M, the specific capacity of the zinc-based dual-ion battery is the highest.

Examples 30-32 compared to example 1, the separators used were different and the electrochemical performance of the resulting zinc-based bi-ion cells did not differ much.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A zinc-based dual ion battery comprising a positive electrode and a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte, wherein,

the electrolyte is a non-aqueous zinc salt electrolyte, and the non-aqueous zinc salt electrolyte is a mixed solution formed by bis (trifluoromethanesulfonyl) imide zinc and N-butyl-N-methylpyrrolidine bis (trifluoromethanesulfonyl) imide salt;

the positive electrode comprises a positive electrode current collector and a positive electrode material combined on the surface of the positive electrode current collector, wherein the positive electrode material contains a positive electrode active material, and the positive electrode active material is a layered material capable of allowing anions forming zinc salt to be reversibly embedded and extracted; wherein the positive electrode active material is expanded graphite;

the negative electrode is a zinc foil which is used as a negative current collector and a negative active material at the same time and is used for reversible deposition and dissolution of zinc ions.

2. The zinc-based dual-ion battery as claimed in claim 1, wherein the zinc salt electrolyte further contains an additive, and the mass percentage of the additive in the zinc salt electrolyte is 0.1-20%.

3. The zinc-based diionic battery of claim 1 or 2, wherein said zinc salt electrolyte has a concentration of 0.1 to 10 mol/L.

4. A preparation method of a zinc-based dual-ion battery is characterized by comprising the following steps:

providing a positive electrode, a negative electrode, a zinc salt electrolyte and a separator of a zinc-based bi-ionic battery according to the composition of any one of claims 1 to 3;