WO2020233264A1 - Gas adsorbent, secondary battery and device - Google Patents

Abstract

The present application belongs to the technical field of batteries, and more specifically relates to a gas adsorbent, a secondary battery and a device. The gas adsorbent comprises a cuprous ion compound and a porous material. The gas adsorbent has both a high specific surface area and chemical properties of a complex reaction with CO, and can timely reduce the internal pressure caused by gas generated from the interaction between pole pieces of the cell and the electrolyte, reduce the swelling and interface impedance of the cell, and extend the life of the battery. The gas adsorbent is encapsulated by using a porous gas-permeable thin film and disposed inside the cell. The structure is simple and easy for industrial production and manufacturing.

Description

Gas adsorbent, secondary battery and device

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on May 23, 2019, the application number is 201910432386.6, and the application title is "A gas adsorbent that can extend the life of lithium-ion batteries and lithium-ion batteries". The entire content is incorporated into this application by reference.

Technical field

This application belongs to the field of battery technology, and more specifically relates to a gas adsorbent, a secondary battery and a device.

Background technique

In recent years, new energy vehicles have developed vigorously due to their energy-saving and environmentally friendly features. However, its large-scale industrialization faces several major problems, including high costs, mileage anxiety and low energy density. New energy vehicles are mainly composed of battery drive system, motor system, electronic control system and assembly. Among them, the motor, electronic control and assembly are basically the same as those of traditional fuel vehicles, and the reason for the price difference lies in the battery drive system. Battery drive systems account for 30-45% of the cost of new energy vehicles, and power secondary batteries account for about 75-85% of the cost of battery drive systems.

The power secondary battery is composed of a positive electrode, a negative electrode, a non-aqueous electrolyte and a separator. In the field of passenger cars, ternary nickel-cobalt-manganese materials (NCM) have become the mainstream of the market as a positive electrode material. This is because the energy density of NCM is higher than that of lithium iron phosphate (LFP), which can provide more energy in a limited space to overcome mileage anxiety. However, gas production in NCM system secondary batteries has always been a serious problem. The gas production mechanism is very complicated, which comes from many reasons, and is related to the positive electrode, the negative electrode, and the electrolyte. For example, the positive electrode potential of NCM as a positive electrode material is relatively high, and the non-aqueous solvent in the electrolyte is easy to decompose under the working environment. , The gas generated inside the battery contains CO ₂ , CO, CH ₄ , C ₂ H ₄ , C ₂ H ₆ , H ₂ and other components. For NCM system batteries, CO ₂ and CO account for the largest proportion.

The electrolyte formula can be improved to form an inorganic salt protective film on the surface of the positive and negative electrodes to reduce side reactions of the positive and negative electrodes at high temperatures, thereby reducing gas production, but the formed inorganic salt protective film has higher impedance and poor wettability. It is also necessary to add additional additives to improve impedance and wettability for synergistic effect, which greatly increases the complexity and cost of the components in the electrolyte. Since the decomposition of non-aqueous solvents is unavoidable from a thermodynamic point of view, some solution mechanism needs to be found at the cell level to absorb the gas generated in the cell to reduce the internal pressure of the cell.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-146963) discloses a secondary battery in which a gas adsorbent is added to a separator substrate. Patent Document 2 (PCT WO2011/135818JA2011.11.03) discloses a gas adsorption layer in which a structural material containing an inorganic substance and a binder are added to a positive electrode or a negative electrode. The methods of Patent Documents 1 and 2 are to mix a gas adsorbent into the separator substrate or pole pieces, but these two methods may damage the porosity of the separator, reduce thermal stability, and reduce the internal resistance and reaction activity of the positive electrode/negative electrode.

Patent Document 3 (Chinese Patent Application CN106159122A) discloses a battery shell structure, including a gas adsorption layer, a first adhesive layer, a gas barrier layer, a second adhesive layer and an outer protective layer. But this kind of battery shell structure is very complicated, mass production manufacturability is very poor, and the cost is high.

Summary of the invention

In view of the above-mentioned problems in the background art, there is a need to provide a gas adsorbent, a secondary battery, and a device. The gas adsorbent needs to be able to quickly react with CO in the gas generated inside the battery to reduce the pressure in the battery, and The use of the gas adsorbent in a secondary battery requires a simple structure, so that the secondary battery has both thermal stability, good separator porosity, and positive/negative internal resistance and reaction activity.

To achieve the above objective, in the first aspect of the present application, a gas adsorbent is provided, which includes a cuprous ion compound and a porous material.

In the second aspect of the present application, a method for preparing a gas adsorbent is provided, which can quickly and efficiently prepare the gas adsorbent of the first aspect of the present application.

In a third aspect of the present application, a secondary battery is provided, which includes the gas adsorbent of the first aspect of the present application.

In the fourth aspect of the present application, a method for preparing a secondary battery is provided, which can quickly and efficiently manufacture the secondary battery of the third aspect of the present application.

In a fifth aspect of the present application, a device is provided, which includes the secondary battery of the third aspect of the present application.

Compared with the prior art, the technical solution of this application has at least the following beneficial effects:

The gas adsorbent has both high specific surface area and chemical properties of complex reaction with CO, and can

Timely reduce the internal pressure caused by the gas generated by the interaction between the pole pieces of the battery cell and the electrolyte, reduce the swelling and interface impedance of the battery cell, and extend the service life of the battery.

When the gas adsorbent is packaged and placed in the top seal space inside the cell, the structure is simple and easy to industrial production and manufacture. Under the action of the gas adsorbent, the service life of the secondary battery of the present application is prolonged. The preparation method of the secondary battery of the present application helps to efficiently obtain a secondary battery with a longer service life. The device of the present application includes the secondary battery provided by the present application, and thus has at least the same advantages as the secondary battery.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the following will briefly introduce the drawings that need to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. A person of ordinary skill in the art can obtain other drawings based on the drawings without creative work.

Fig. 1 is a schematic diagram of an embodiment of a secondary battery.

Figure 2 is an exploded view of Figure 1.

Fig. 3 is a schematic diagram of an embodiment of a battery module.

Fig. 4 is a schematic diagram of an embodiment of a battery pack.

Fig. 5 is an exploded view of Fig. 4.

Fig. 6 is a schematic diagram of an embodiment of a device in which a secondary battery is used as a power source.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, not all of them.的实施例。 Example. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

The first aspect of the present application provides a gas adsorbent, which includes a cuprous ion compound and a porous material.

The gas adsorption rate of the gas adsorbent is 0.4-1 mmol/h, preferably 0.7-1 mmol/h.

The contribution of the cuprous ion compound in the gas adsorbent is to provide cuprous ions. The cuprous ions can undergo a complex reaction with the main gas CO whose pressure inside the cell increases, and consume the main gas CO produced. The function of the porous material The main purpose is to provide a microporous support matrix with appropriate pore size to achieve a high gas adsorbent specific surface area that meets the requirements, and capture and adsorb CO, CO ₂ and other major gases. The principle of the complex reaction between cuprous ions and CO is: there is a lone pair of electrons on the C of CO. After the copper ion loses one electron to form cuprous ions, the 4s orbit becomes empty and the lone pair of electrons on C occupies the cuprous ions. 4s empty orbit, the two form a complex. The selection and grading of cuprous ion compounds and porous materials need to meet certain gas adsorption rate requirements, thereby reducing the air pressure generated inside the cell, so as to achieve the purpose of reducing cell swelling and interface impedance, and extending the service life of the cell.

Furthermore, when introducing the precursor of the main active component of the cuprous ion, it should be considered that the melting point is not too high, the preparation is relatively easy, and the compound is relatively stable. Therefore, the oxo acid salt or inorganic salt of the cuprous ion is used. Preferably, the cuprous ion compound is selected from one or more of cuprous oxide, cuprous sulfide, cuprous carboxylate, cuprous sulfate, cuprous carbonate and cuprous nitrate.

Preferably, the porous material is selected from one or more of A-type, Y-type, X-type, ZSM-type molecular sieves and aluminum phosphate molecular sieves. Molecular sieves are currently porous materials with large specific surface area and low cost.

Preferably, the pore size of the porous material is

Preferably

This pore size range allows CO molecules to enter the porous material, and can minimize the electrolyte solvent molecules from entering the porous material. When the pore size of the porous material is improperly selected (over

Outside the range), although the purpose of this application can be achieved to a certain extent, its performance is not outstanding enough. This is because the solvent molecules of the electrolyte will be continuously absorbed by the porous material and cause its saturation, thereby losing the CO and CO ₂ Capture ability, so special attention needs to be paid to the selection of porous materials with high specific surface area or the selection of closed membranes.

Preferably, the specific surface area of the porous material is 400-1000 m ² /g, preferably 800-1000 m ² /g. The larger the specific surface area, the more cuprous compounds can be dispersed on the surface, and the better the gas absorption effect.

Preferably, the weight ratio of the cuprous ion compound to the porous material is 1:10-1:1, preferably 1:4-1:2. The weight ratio of the cuprous ion compound and the porous material is very important for the effective realization of the purpose of this application. If the ratio of the two is not appropriate, although the purpose of this application can be achieved, it will have a certain influence on the gas absorption effect. This is because if the weight ratio of cuprous ion compound to porous material is too high, there will be too much cuprous ion compound, and the surplus part will not be distributed on the surface of the porous material, and this part will not be able to effectively absorb CO; such as cuprous ion compound and porous material If the weight ratio of the material is too low, there will be too much porous material, and there will be no cuprous ion compound distributed on the surface of a part of the porous material, and this part of the porous material will not function effectively.

Preferably, based on the nominal capacity of the battery cell per 1 Ah, the total amount of the cuprous ion compound is 6×10 ^-6 -6×10 ^-5 mol, preferably 8×10 ^-6 -2×10 ^-5 mol. The generation of gas in the battery is related to the capacity of the battery cell. Therefore, the total amount of the cuprous ion compound needs to be controlled within a certain range to achieve the dual performance of effective gas absorption and reasonable control of the battery weight.

In the specific implementation process, the gas adsorbent of the present invention is prepared by a method including the following process: in an environment that is isolated from water and oxygen, the cuprous ion compound and the porous material are mixed and stirred, and then the cuprous ion The compound melts to obtain the gas adsorbent.

The second aspect of the application is to provide a method for preparing the above-mentioned gas adsorbent, which includes: mixing and stirring the cuprous ion compound with a porous material in an environment that is isolated from water and oxygen, and then melting the cuprous ion compound , To obtain the gas adsorbent.

A third aspect of the present application provides a secondary battery, which includes the gas adsorbent described in the first aspect of the present application.

The secondary battery in the present application refers to a battery that can be used repeatedly in charge and discharge cycles, including but not limited to lithium ion batteries, sodium ion batteries, and the like.

Preferably, the gas adsorbent described in the first aspect of the present application is encapsulated in a porous gas-permeable film and placed in the battery cell of the secondary battery; more preferably, it is placed in the top seal space of the battery cell of the secondary battery.

Preferably, the porous air-permeable film is one or more of microporous membranes, woven films, non-woven films, fiber paper, laminated films and composite films. These films have low cost, suitable thickness and pore size, strong manufacturability, and strength to meet the requirements.

Preferably, the pore size of the porous breathable film is

Preferably

The pore size of the porous and gas-permeable membrane allows CO molecules to pass through the membrane, and can prevent electrolyte solvent molecules from passing through the membrane to the greatest extent. The solvent molecules of the electrolyte will be continuously absorbed by the porous and gas-permeable film, resulting in saturation, thereby losing the ability to capture CO and CO _2. Therefore, special attention should be paid to the selection of a porous and gas-permeable film with a high specific surface area or the selection of a closed film.

The secondary battery of the present application also includes a positive pole piece, a negative pole piece, a separator and an electrolyte. In the process of battery charging and discharging, active ions are inserted and extracted back and forth between the positive pole piece and the negative pole piece. The isolation film is arranged between the positive pole piece and the negative pole piece to play a role of isolation. The electrolyte conducts ions between the positive pole piece and the negative pole piece. In addition to the use of the gas adsorbent of the first aspect of the present application, the structure and manufacturing method of the secondary battery of the present application are known per se. The technical personnel of the present application can select suitable materials according to the application requirements to prepare the above-mentioned positive pole piece, negative pole piece, separator and electrolyte.

The present application has no particular limitation on the shape of the secondary battery, which may be cylindrical, square or other arbitrary shapes. Fig. 1 shows a secondary battery 5 having a square structure as an example.

In some embodiments, the secondary battery may include an outer package for packaging the positive pole piece, the negative pole piece, the separator and the electrolyte.

In some embodiments, the outer packaging of the secondary battery may be a soft bag, such as a pouch type soft bag. The material of the soft bag can be plastic, for example, it can include one or more of polypropylene PP, polybutylene terephthalate PBT, polybutylene succinate PBS, and the like. The outer packaging of the secondary battery may also be a hard shell, such as a hard plastic shell, aluminum shell, steel shell, and the like.

In some embodiments, referring to FIG. 2, the outer package may include a housing 51 and a cover 53. Wherein, the housing 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The housing 51 has an opening communicating with the containing cavity, and a cover plate 53 can cover the opening to close the containing cavity.

The positive pole piece, the negative pole piece, and the separator may be formed into the cell 52 through a winding process or a lamination process. The battery core 52 is encapsulated in the containing cavity. The electrolyte is infiltrated in the cell 52.

The number of battery cells 52 contained in the secondary battery 5 can be one or several, which can be adjusted according to requirements.

In some embodiments, the secondary battery can be assembled into a battery module, and the number of secondary batteries contained in the battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module.

FIG. 3 is a battery module 4 as an example. Referring to FIG. 3, in the battery module 4, a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4. Of course, it can also be arranged in any other manner. Furthermore, the plurality of secondary batteries 5 can be fixed by fasteners.

Optionally, the battery module 4 may further include a housing having an accommodation space, and a plurality of secondary batteries 5 are accommodated in the accommodation space.

In some embodiments, the above-mentioned battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.

4 and 5 are the battery pack 1 as an example. 4 and 5, the battery pack 1 may include a battery box and a plurality of battery modules 4 provided in the battery box. The battery box includes an upper box body 2 and a lower box body 3. The upper box body 2 can be covered on the lower box body 3 and forms a closed space for accommodating the battery module 4. Multiple battery modules 4 can be arranged in the battery box in any manner.

The fourth aspect of the present application provides a method for preparing a secondary battery, including the steps of encapsulating the gas adsorbent of the first aspect in a porous gas-permeable film and placing it in a battery cell of the secondary battery. Preferably, it includes the step of encapsulating the gas adsorbent of the first aspect into a porous gas-permeable film and placing it in the top seal space of the cell of the secondary battery.

A fifth aspect of the present application provides a device, which includes the secondary battery described in the third aspect of the present application. The secondary battery can be used as a power source of the device, and can also be used as an energy storage unit of the device. The device can be, but is not limited to, mobile devices (such as mobile phones, laptop computers, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf Vehicles, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

The device can select a secondary battery, battery module, or battery pack according to its usage requirements.

Figure 6 is a device as an example. The device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. In order to meet the requirements of the device for high power and high energy density of the battery, a battery pack or battery module can be used.

As another example, the device may be a mobile phone, a tablet computer, a notebook computer, etc. The device is generally required to be thin and light, and a secondary battery can be used as a power source.

In order to describe in detail the technical content, structural features, achieved objectives and effects of the technical solution, the following detailed description will be given in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. Because it is obvious to those skilled in the art to make various modifications and changes within the scope of the disclosure of this application. All reagents used in the examples are commercially available or synthesized according to conventional methods, and can be used directly without further processing, and the instruments used in the examples are all commercially available.

The batteries of Examples 1-14 and Comparative Examples 1-2 were prepared according to the following methods.

(1) Preparation of positive pole piece

The positive electrode active material LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , the conductive agent Super-P, and the binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 94:3:3, and the solvent N- Methylpyrrolidone (NMP), stir under the action of a vacuum mixer until the system is uniform to obtain the positive electrode slurry; evenly coat the positive electrode slurry on the two surfaces of the positive electrode current collector aluminum foil, dry at room temperature and transfer to the oven to continue After drying, cold pressing and slitting, a positive pole piece is obtained.

(2) Preparation of negative pole piece

Mix the negative electrode active material, the conductive agent Super P, the thickener sodium carboxymethyl cellulose (CMC), and the binder styrene butadiene rubber emulsion (SBR) in a mass ratio of 96:1:1:2, and add them to the solvent. In ionized water, stir evenly under the action of a vacuum mixer to obtain negative electrode slurry; evenly coat the negative electrode slurry on the copper foil of the negative current collector, dry at room temperature and transfer to an oven to continue drying, and then undergo cold pressing, trimming, and cutting The slices and slits are moved to a vacuum oven to obtain negative pole pieces.

(3) Preparation of electrolyte

Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are mixed in a volume ratio of 3:7 to obtain an organic solvent, and then fully dried LiPF _{6 is} dissolved in the mixed organic solvent to prepare a concentration of 1 mol/L Of electrolyte.

(4) Preparation of isolation membrane

Choose PE/PP/PE three-layer porous polymer film as the isolation membrane.

(5) Preparation of gas adsorbent

Mix the cuprous ion compound shown in Table 1 with the porous material in an environment where there is no CO, CO ₂ , O ₂ , H ₂ O and other oxidizing substances, and separate moisture and oxygen in a sealed container for stirring 1- 24h, get uniform mixed powder, heat for 1-24h at high temperature (80-750℃), cuprous ion compound powder melts at high temperature, and evenly penetrates into the inside and surface of porous material with high specific surface, that is The gas adsorbent.

(6) Preparation of secondary battery

Lay the above-mentioned positive pole piece, separator film, and negative pole piece in order, so that the separator film is located between the positive and negative pole pieces for isolation, and then wound to obtain a bare cell; the parameters shown in Table 1 are as follows ( 5) The prepared gas adsorbent is packaged into the microporous membranes with different pore diameters as shown in Table 1, and placed in the inner top sealing space of the battery cell of the secondary battery, and the bare cell is placed in the outer packaging shell, after drying The electrolyte is injected, and the secondary battery is obtained after vacuum packaging, standing, forming, and shaping.

The following describes the experimental measurement method of the internal gas pressure and the gas adsorption rate of the cell of the secondary battery containing the gas adsorbent.

(1) Measuring method of air pressure inside the cell

Connect a pressure gauge to the top cover of the cell. After the count is cleared, place the cell in a high and low temperature box with a temperature of 70° and let it stand. Read the pressure gauge daily until the pressure gauge reads 0.35MPa So far, the number of days it took to reach 0.35 MPa was recorded.

(2) Gas adsorption rate measurement method

Place 5g of the gas adsorbent in a confined space, fill the confined space with carbon monoxide gas CO to a positive pressure of 0.1 MPa, stand for 2-8 hours, monitor the air pressure in real time, and finally calculate the adsorption rate.

Table 1 Gas adsorbent and relevant parameters of secondary battery cells

From the data in Table 1, it can be seen that Examples 1-5 show that the effect of prolonging the battery life of high-temperature storage and gas production is related to the weight ratio of cuprous ion compound to porous material, and the weight ratio of cuprous ion compound to porous material is 1:4 The best effect is in the range of -1:2. If the weight ratio of the cuprous ion compound to the porous material is too high, that is, if there is too much cuprous ion compound, the surplus part will not be distributed on the surface of the porous material. This part will not be able to effectively absorb CO, such as the weight of the cuprous ion compound and the porous material If the ratio is too low, there are too many porous materials, and there will be no cuprous ion compound distributed on the surface of a part of the porous material, and this part of the porous material will not function effectively.

Examples 3 and 6 show that the effect of prolonging the life of the cell during high-temperature storage and gas production is related to the type of porous material, and type A is better than type X.

Examples 6 and 7 illustrate that the effect of prolonging the life of the battery during high-temperature storage and gas production is related to the types of cuprous ion compounds, and that cuprous sulfide has a better effect than cuprous chloride.

Examples 5, 8, and 9 illustrate that the effect of prolonging the life of the battery during high temperature storage and gas production is related to the pore size of the porous material.

The effect is best within the range. The pore size can allow CO molecules to enter the porous material, and can avoid the electrolyte solvent molecules from entering the porous material to the greatest extent. For example, the solvent molecules of the electrolyte are too much absorbed by the porous material and cause its saturation, which will make it porous The material loses its ability to capture CO and CO ₂ .

Examples 8, 10, and 11 illustrate that the effect of prolonging the life of the battery during high-temperature storage and gas production is related to the porous, breathable and thin pore size.

The best effect within the range, the pore size can allow CO molecules to pass through the membrane, and can avoid the electrolyte solvent molecules from penetrating the membrane to the greatest extent. For example, the electrolyte solvent molecules pass through the membrane too much and are absorbed by the porous and breathable membrane. Its saturation will cause the porous and breathable film to lose its ability to capture CO and CO ₂ .

Examples 10, 12-14 illustrate that the effect of prolonging the life of the battery during high temperature storage and gas production is related to the ratio of the total amount of cuprous ion compounds to the cell capacity. The ratio of the total amount of cuprous ion compounds to the cell capacity is 8× The effect is best in the range of 10 ^-6 -2×10 ^-5 . If it is too small, the gas cannot be absorbed completely, and if it is too much, the adsorbent will have a surplus, which will reduce the energy density of the cell.

In the comparative example, the adsorbent without cuprous ion compound or porous material has no effect of prolonging the life of the battery during high temperature storage and gas production.

It should be noted that although the foregoing embodiments have been described in this article, this does not limit the scope of patent protection of this application. Therefore, based on the innovative ideas of this application, changes and modifications to the embodiments described herein, or equivalent structures or equivalent process transformations made by using the contents of the specification of this application, directly or indirectly apply the above technical solutions to other related The technical fields of are included in the scope of patent protection of this application.

Claims (23)

1. A gas adsorbent includes a cuprous ion compound and a porous material.
2. The gas adsorbent according to claim 1, wherein the gas adsorption rate is 0.4-1 mmol/h.
3. The gas adsorbent according to claim 2, wherein the gas adsorption rate is 0.7-1 mmol/h.
4. The gas adsorbent according to any one of claims 1 to 3, wherein the cuprous ion compound is selected from cuprous oxide, cuprous sulfide, cuprous carboxylate, cuprous sulfate, cuprous carbonate and cuprous nitrate One or more of them.
5. The gas adsorbent according to any one of claims 1 to 4, wherein the porous material is selected from one or more of A-type, Y-type, X-type, ZSM-type molecular sieves and aluminum phosphate molecular sieves.
6. The gas adsorbent according to any one of claims 1-5, wherein the pore size of the porous material is

   
7. The gas adsorbent according to claim 6, wherein the pore size of the porous material is

   
8. The gas adsorbent according to any one of claims 1-7, wherein the specific surface area of the porous material is 400-1000 m ² /g.
9. The gas adsorbent according to claim 8, wherein the specific surface area of the porous material is 800-1000 m ² /g.
10. The gas adsorbent according to any one of claims 1-9, wherein the weight ratio of the cuprous ion compound to the porous material is 1:10-1:1.
11. The gas adsorbent according to claim 10, wherein the weight ratio of the cuprous ion compound to the porous material is 1:4-1:2.
12. The gas adsorbent according to any one of claims 1-11, wherein, based on the nominal capacity of the battery cell per 1 Ah, the total amount of the cuprous ion compound is 6×10 ^-6 -6×10 ^-5 mol.
13. The gas adsorbent according to claim 12, wherein the total amount of the cuprous ion compound is 8×10 ^-6 -2×10 ^-5 mol based on the nominal capacity of the battery cell per 1 Ah.
14. The gas adsorbent according to any one of claims 1-13, wherein the gas adsorbent is prepared by a method including the following processes:

    Under the environment of isolating water and oxygen, the cuprous ion compound and the porous material are mixed and stirred, and then the cuprous ion compound is melted to obtain the gas adsorbent.
15. A method for preparing the gas adsorbent according to any one of claims 1-14:

    Under the environment of isolating water and oxygen, the cuprous ion compound and the porous material are mixed and stirred, and then the cuprous ion compound is melted to obtain the gas adsorbent.
16. A secondary battery, wherein the secondary battery includes the gas adsorbent according to any one of claims 1-14.
17. The secondary battery according to claim 16, wherein the gas adsorbent is encapsulated in a porous gas-permeable film and placed in a battery cell of the secondary battery.
18. The secondary battery according to claim 17, wherein the gas adsorbent is encapsulated in a porous and gas-permeable film and placed in the inner cap space of the battery cell of the secondary battery.
19. The secondary battery according to any one of claims 17-18, wherein the porous breathable film is one of a microporous membrane, a woven film, a non-woven film, a fiber paper, a laminated film, and a composite film Or several.
20. The secondary battery according to any one of claims 17-19, wherein the pore size of the porous gas-permeable film is

    
21. The secondary battery according to claim 20, wherein the pore size of the porous gas-permeable film is

    
22. A method for preparing a secondary battery according to any one of claims 16-21, comprising the following steps: encapsulating the gas adsorbent according to any one of claims 1-14 into a porous gas-permeable film, and It is placed in the cell of the secondary battery.
23. A device, wherein the device comprises the secondary battery according to any one of claims 16-21.

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