CN115189076B - Wide-temperature solid metal-air battery and preparation method thereof - Google Patents

Abstract

The invention is applicable to the field of solid metal-air batteries, and provides a wide-temperature solid metal-air battery, which comprises: a C-IL@MOF solid state positive electrode, an IL@MOF solid state electrolyte and a metal negative electrode; the C-IL@MOF solid anode is formed by compounding a conductive catalyst, a metal organic framework material and an ionic liquid; the IL@MOF solid electrolyte is formed by compounding a metal organic framework material and an ionic liquid. A preparation method of a wide-temperature solid metal-air battery comprises the steps of packaging a C-IL@MOF solid positive electrode, an IL@MOF solid electrolyte and a metal negative electrode in the battery from top to bottom. The IL@MOF/C-IL@MOF structure integrating the IL@MOF solid electrolyte and the C-IL@MOF solid positive electrode is used for a wide-temperature solid metal-air battery and shows rapid reaction kinetics, super-ion conductivity and electrochemical durability.

Description

A wide temperature solid-state metal-air battery and preparation method thereof

Technical Field

The present invention belongs to the field of solid-state metal-air batteries, and in particular relates to a wide-temperature solid-state metal-air battery and a preparation method thereof.

Background Art

In inorganic solid electrolytes, inorganic sulfides are unstable in air environments and produce toxic hydrogen sulfide, which is not convenient for use in lithium-air batteries. In addition, perovskite and antiperovskite solid electrolytes exhibit low ionic conductivity. Currently, sodium superionic conductors and garnet solid electrolytes with high ionic conductivity are more studied. However, the large interface resistance caused by the use of solid electrolytes limits the improvement of solid-state battery performance. In terms of polymer electrolytes, gel polymer electrolytes composed of a polymer matrix and a liquid electrolyte have been used in metal-air batteries to solve the solid/solid interface problem. Although gel polymer electrolytes exhibit high ionic conductivity, close to liquid electrolytes, their volatilization problem remains unsolved due to the presence of a certain amount of liquid electrolyte. At the same time, people have tried a new type of flexible metal-air battery with a composite polymer electrolyte without liquid electrolyte, which exhibits a long cycle life and low overpotential at high temperature (55°C). However, its practical application is hindered by temperature dependence. At present, solid electrolytes that combine high ionic conductivity, high stability and good interface contact for metal-air batteries still need to be explored.

In addition, the positive electrode of the metal-air battery is the main site of the battery reaction, and a reaction interface that contains gas, electrons, and ions needs to be constructed. At present, the commonly used method of constructing a solid positive electrode is to ball-mill or co-sinter the solid electrolyte and the positive electrode catalyst, which will result in three interfaces being restricted and thus affect the performance of the solid-state battery. Therefore, constructing a reasonable solid positive electrode for a metal-air battery is also one of the current difficulties.

In order to avoid the above technical problems, it is necessary to provide a wide-temperature solid-state metal-air battery and a preparation method thereof to overcome the above defects in the prior art.

Summary of the invention

The purpose of the present invention is to provide a wide-temperature solid-state metal-air battery and a preparation method thereof, aiming to solve the technical difficulties in preparing a solid electrolyte material with high ionic conductivity and high stability and a porous structure solid positive electrode with good interface contact and continuous electron/ion transport.

The present invention is implemented as follows: a wide temperature solid-state metal-air battery, comprising:

C-IL@MOF solid cathode, IL@MOF solid electrolyte and metal anode;

The C-IL@MOF solid positive electrode is composed of a conductive catalyst, a metal organic framework material and an ionic liquid;

The IL@MOF solid electrolyte is composed of a composite of a metal organic framework material and an ionic liquid.

In a further technical solution, the MOF is a single or multiple material selected from MIL-101, UiO-66, and UiO-67.

In a further technical solution, the IL is a single or multiple material selected from imidazole, pyridine, and quaternary ammonium salt ionic liquids.

In a further technical solution, the C in the C-IL@MOF solid-state positive electrode is a single or multiple materials selected from carbon nanotubes, graphene, and conductive carbon.

According to a further technical solution, the composite method is a grinding and mixing method.

According to a further technical solution, the metal negative electrode is one of a lithium sheet, a sodium sheet, a potassium sheet, a zinc sheet, an iron sheet, a magnesium sheet or an aluminum sheet.

A method for preparing a wide-temperature solid-state metal-air battery, comprising encapsulating a C-IL@MOF solid-state positive electrode, an I L@MOF solid-state electrolyte, and a metal negative electrode in a battery from top to bottom.

The specific steps include:

S1. Preparation of MOF nanoparticles;

S2. Encapsulating the ionic liquid in the MOF nanoparticles prepared in step S1 to obtain IL@MOF nanoparticles;

S3. Pressing the IL@MOF nanoparticles in S2 into discs and IL@MOF solid electrolyte;

S4. Preparation of C-MOF nanoparticles;

S5. encapsulating the ionic liquid in the C-MOF nanoparticles in step S4 to obtain C-I L@MOF nanoparticles;

S6. The IL@MOF nanoparticles obtained in step S2 are pressurized at 1 to 5 MPa for 1 to 5 minutes, and the C-IL@MOF nanoparticles obtained in step S51 are combined with the IL@MOF dense electrolyte layer by spin coating or pressurization to obtain a double-layer integrated IL@MOF/C-IL@MOF skeleton;

S7. Assemble the positive electrode current collector, the integrated I L@MOF/C-I L@MOF skeleton, and the negative electrode lithium sheet in a 2025-type button cell from top to bottom;

S8. The battery obtained in step S7 is placed in a self-made sealed container. The air inside the container can be replaced with various atmospheres, and the container can be placed at different ambient temperatures.

The self-made sealed container can be made of glass, quartz, acrylic glass, or stainless steel;

The air is converted into different atmospheres by means of a double-way switch of the sealed container to extract and release the air;

The different ambient temperatures refer to ambient temperatures ranging from -60°C to 150°C.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention provides an I L@MOF/C-IL@MOF structure integrating an I L@MOF solid electrolyte and a C-I L@MOF solid positive electrode for a wide-temperature solid-state metal-air battery, which exhibits fast reaction kinetics, superionic conductivity and electrochemical durability.

(1) IL@MOF, as a stable solid-state electrolyte, exhibits exceptionally high ionic conductivity and high lithium ion transfer number at room temperature, which is due to the strong interaction between the MOF framework and the ionic liquid, which can effectively inhibit the movement of anions.

(2) Since IL is encapsulated in the unique porous structure of MOF, IL@MOF exhibits high ionic conductivity over a wide temperature range (−60 to 150 °C).

(3) In addition, the C-IL@MOF nanoreactor provides continuous mass transfer channels and abundant three-phase boundaries, which effectively accelerates the redox kinetics.

(4) Benefiting from the nano-wetting interface between IL@MOF and the electrode, solid-state metal-air batteries exhibit ultra-low impedance, high round-trip efficiency, and good rate performance at room temperature.

(5) Solid-state metal-air batteries exhibit an ultra-wide operating temperature window (-60°C to 150°C) and are expected to be used in complex and changing environments.

This research is not limited to metal-air batteries but can also be applied to other battery systems, constituting an important step towards the practical application of all-solid-state metal-air batteries.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a corresponding Arrhenius plot of the ionic conductivity of the IL@MOF solid electrolyte of Example 1 of the present invention from -60°C to 150°C.

FIG. 2 is a DC polarization curve of the IL@MOF solid electrolyte of Example 1 of the present invention at room temperature.

FIG3 is a scanning electron microscope image of the CNT-IL@MOF solid-state cathode of Example 2 of the present invention.

FIG4 is a cyclic voltammetry curve of the CNT-IL@MOF solid-state cathode prepared in Example 2 of the present invention.

FIG5 is an in-situ electrochemical impedance test of the wide temperature solid-state lithium carbon dioxide battery prepared in Example 3 of the present invention during the charge and discharge process.

FIG6 is a charge and discharge voltage curve of the wide temperature solid-state lithium carbon dioxide battery prepared in Example 3 of the present invention under an environment of -60°C to 150°C.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

A wide-temperature solid-state metal-air battery, comprising:

C-I L@MOF solid cathode, I L@MOF solid electrolyte and metal anode;

The C-I L@MOF solid positive electrode is composited with a conductive catalyst, a metal organic framework material and an ionic liquid; the C-I L@MOF solid positive electrode has the advantages of high electronic conductivity, high ionic conductivity and high redox kinetics;

The IL@MOF solid electrolyte is composed of a metal organic framework material and an ionic liquid. The IL@MOF solid electrolyte has the advantages of high ionic conductivity, high stability and good interface contact.

The MOF includes single or multiple materials such as MIL-101, UiO-66, UiO-67, etc., and the MOF is preferably MIL-101 (Cr).

The IL includes ionic liquids such as imidazoles, pyridines, and quaternary ammonium salts, and is preferably 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

The C in the C-IL@MOF solid-state positive electrode includes conductive catalysts such as carbon nanotubes (CNTs), graphene, and conductive carbon; the C is preferably a carbon nanotube.

The compounding method is a grinding and mixing method.

The metal negative electrode is a lithium sheet.

A method for preparing a wide-temperature solid-state metal-air battery, comprising encapsulating a C-IL@MOF solid-state positive electrode, an IL@MOF solid-state electrolyte, and a metal negative electrode in a battery from top to bottom.

Example 1

Preparation of IL@MOF solid electrolyte:

1. Add 2.5 mmol Cr(NO ₃ ) ₃ ·9H ₂ O and 2.5 mmol terephthalic acid into 10 mL deionized water. After ultrasonic treatment, transfer the solution to a reactor and heat it to 200°C for 24 hours. Allow the solution to cool and centrifuge to obtain the product. Place the product in N,N-dimethylformamide and stir at 100°C for 24 hours. Finally, filter the green product and vacuum dry it at 120°C to obtain green powder MOF nanoparticles;

2. Dissolve lithium bis(trifluoromethanesulfonyl)imide in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide to prepare 1M I L. Mix I L and green powder MOF nanoparticles in a ratio of 1:5, and then vacuum dry at 120°C to obtain I L@MOF nanoparticles;

3. Fill the IL@MOF nanoparticles into a 16 mm diameter round tableting mold and pressurize at 5 MPa for 5 minutes to obtain the IL@MOF solid electrolyte;

The IL@MOF solid electrolyte prepared in Example 1 of the present invention was characterized.

See Figure 1, the corresponding Arrhenius plot of the ionic conductivity of the IL@MOF solid electrolyte from -60°C to 150°C.

As shown in FIG. 1 , the IL@MOF solid electrolyte prepared in the present invention exhibits high ion conductivity in a wide temperature range (-60° C. to 150° C.), and the ion conductivity can reach 1.0 mScm ⁻¹ at room temperature.

See FIG. 2 , which is a DC polarization curve of the IL@MOF solid electrolyte in the present invention at room temperature.

As can be seen from the curve in FIG2 , the lithium ion transfer number of the IL@MOF solid electrolyte prepared in the present invention is as high as 0.8, which is attributed to the fact that the MOF skeleton can effectively restrict the movement of internal ionic liquid anions.

Example 2

Preparation of CNT-IL@MOF solid-state cathode:

1. Add 1gCr(NO ₃ ) ₃ ·9H ₂ O and 0.415g terephthalic acid to 10mL deionized water, stir until a transparent solution is added, and then CNTs are added. After ultrasonic treatment, the solution is transferred to a reactor and heated to 200°C for 24 hours. After the solution is cooled, centrifuge to obtain the product. The product is placed in N,N-dimethylformamide and stirred at 100°C for 24 hours. Finally, the green product is filtered and vacuum dried at 120°C to obtain green powder MOF nanoparticles;

2. Dissolve lithium bis(trifluoromethanesulfonyl)imide in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide to prepare 1MIL. Mix IL and black CNT-MOF nanoparticles in a ratio of 1:5, and then vacuum dry at 120°C to obtain black CNT-IL@MOF nanoparticles;

3. Fill the CNT-IL@MOF nanoparticles into a 16 mm diameter round tableting mold and pressurize at 3 MPa for 5 minutes to obtain a CNT-IL@MOF solid positive electrode;

The CNT-IL@MOF solid positive electrode prepared in Example 2 of the present invention.

See Figure 3, which is a scanning electron microscope image of the CNT-IL@MOF solid-state positive electrode prepared by the present invention.

As shown in Figure 3, the CNT-IL@MOF solid-state cathode forms a continuous electron-ion conduction network with rich three-phase reaction interfaces.

See Figure 4, which is a cyclic voltammetry curve of the CNT-IL@MOF solid-state positive electrode prepared by the present invention.

As shown in Figure 4, compared with CNT-IL, CNT-IL@MOF shows higher reduction and oxidation currents and more obvious redox peaks. Since the CNT-IL@MOF cathode has more effective electrochemical active sites, the kinetics of the carbon dioxide reduction and evolution reaction process can be significantly improved.

Example 3

Preparation of wide temperature solid-state lithium carbon dioxide battery:

1. The I L@MOF nanoparticles obtained above were pressurized at 5 MPa for 5 minutes, and the black CNT-I L@MOF nanoparticles were combined with the I L@MOF dense electrolyte layer by spin coating or pressurization to obtain a double-layer integrated I L@MOF/CNT-I L@MOF skeleton.

2. Assemble the positive electrode current collector, integrated IL@MOF/CNT-IL@MOF skeleton, and negative electrode lithium sheet in a 2025 button cell from top to bottom; test the wide-temperature solid-state lithium carbon dioxide battery at different temperatures (-60℃ to 150℃).

The wide-temperature solid-state lithium carbon dioxide battery prepared in Example 3 of the present invention was characterized.

See FIG. 5 , which is an in-situ electrochemical impedance test of the wide temperature solid-state lithium carbon dioxide battery prepared by the present invention during the charge and discharge process.

As shown in Figure 5, the total resistance of the solid-state lithium CO2 battery is 100Ω due to the nano-wetting of the electrolyte and electrode interface. Thanks to the fast carbon dioxide reduction/evolution reaction process kinetics, the solid-state lithium CO2 battery still maintains 100Ω after the charge and discharge process.

See FIG. 6 , which is a charge and discharge voltage curve of the wide temperature solid-state lithium carbon dioxide battery prepared by the present invention in an environment of -60° C. to 150° C.

As shown in Figure 6, the wide-temperature solid-state lithium carbon dioxide battery can operate normally even at -60°C. When the operating temperature increases from 30°C to 150°C, an ultra-high round-trip efficiency of up to 90% is achieved. When the temperature returns to 25°C, the overpotential of the wide-temperature solid-state lithium carbon dioxide battery can almost be restored to the original overpotential. In sharp contrast, the liquid lithium carbon dioxide battery using ionic liquid electrolyte and CNT positive electrode cannot operate at -40°C. When the temperature returns to 25°C, the overpotential of the liquid lithium carbon dioxide battery cannot be restored. These results demonstrate that the solid-state lithium carbon dioxide battery using I L@MOF/CNT-I L@MOF has excellent environmental adaptability and exhibits significant heat and freeze resistance.

We proposed and prepared a new wide-temperature solid-state metal-air battery for the first time, which includes a metal anode, an I L@MOF solid electrolyte, and a C-I L@MOF solid cathode. Solid-state metal-air batteries with a reasonable structure can achieve high efficiency and work stably in a wide temperature window.

(1) The mobility of IL encapsulated in the MOF lattice is restricted, which can well avoid the risk of electrolyte leakage; MOF provides a stable three-dimensional open rigid solid framework to ensure the dynamics of the interface, thereby achieving high ionic conductivity and high lithium ion transfer number.

(2) C-IL@MOF meets the three criteria of solid-state cathodes, namely, high electronic conductivity, high ionic conductivity, and high redox kinetics.

(3) Benefiting from the nano-wetting interface between IL@MOF and the electrode, the solid-state metal-air battery exhibits ultra-low resistance, high round-trip efficiency and good rate performance at room temperature. At the same time, the solid-state metal-air battery exhibits an ultra-wide operating temperature window (-60℃ to 150℃), which is expected to be applied in complex and changing environments.

Solid-state metal-air batteries with rational designs show great promise for safely using energy storage devices over a complex wide temperature range.

In summary, the key breakthroughs in solid-state electrolytes and solid-state positive electrodes provide guarantees for the safety and stability of high-energy-density lithium-carbon dioxide batteries, and also provide a feasible strategy for other metal-air batteries and secondary energy storage systems.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims (2)

1. A wide temperature solid-state metal-air battery, comprising: C-IL@MOF solid cathode, IL@MOF solid electrolyte and metal anode; The C-IL@MOF solid positive electrode is composited with a conductive catalyst, a metal organic framework material and an ionic liquid, and the C in the C-IL@MOF solid positive electrode is a single material or two materials selected from carbon nanotubes and graphene; The IL@MOF solid electrolyte is composed of a metal organic framework material and an ionic liquid. The ionic liquid is prepared by dissolving lithium bis(trifluoromethanesulfonyl)imide into 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide; The MOF is MIL-101; The preparation method of the wide temperature solid-state metal-air battery comprises encapsulating a C-IL@MOF solid-state positive electrode, an IL@MOF solid-state electrolyte and a metal negative electrode in a battery from top to bottom; specifically comprising the following steps: S1. Preparation of MOF nanoparticles; S2. Encapsulating the ionic liquid in the MOF nanoparticles prepared in step S1 to obtain IL@MOF nanoparticles; S3. Pressing the IL@MOF nanoparticles in S2 into discs, i.e., IL@MOF solid electrolyte; S4. Preparation of C-MOF nanoparticles; S5. The ionic liquid and the C-MOF nanoparticles of step S4 are mixed in a certain proportion and then vacuum dried at 120°C to encapsulate the ionic liquid in the C-MOF nanoparticles to obtain C-IL@MOF nanoparticles; S6. The IL@MOF nanoparticles obtained in step S2 are pressurized at 1 to 5 MPa for 1 to 5 minutes, and the C-IL@MOF nanoparticles obtained in step S5 are combined with the IL@MOF dense electrolyte layer by spin coating or pressurization to obtain a double-layer integrated IL@MOF/C-IL@MOF skeleton; S7. Assemble the cathode current collector, integrated IL@MOF/C-IL@MOF skeleton, and anode lithium sheet in a 2025-type button cell from top to bottom; S8. The battery obtained in step S7 is placed in a homemade sealed container; The wide temperature solid-state metal air battery is a wide temperature solid-state lithium carbon dioxide battery; the wide temperature refers to -60°C to 150°C. 2. The wide temperature solid-state metal-air battery according to claim 1, characterized in that the composite method is a grinding and mixing method.