CN112103600B

CN112103600B - Laminated soft-package metal-air battery and preparation method thereof

Info

Publication number: CN112103600B
Application number: CN202010803238.3A
Authority: CN
Inventors: 何平; 杨金贵; 周豪慎
Original assignee: Nanjing University
Current assignee: Nanjing University
Priority date: 2020-08-11
Filing date: 2020-08-11
Publication date: 2022-04-22
Anticipated expiration: 2040-08-11
Also published as: CN112103600A

Abstract

The invention discloses a laminated soft-package metal-air battery and a preparation method thereof, wherein the laminated soft-package metal-air battery consists of a packaging shell, an electric core groove, an electric core, electrolyte, an electrolyte injection device and a gas conduction device; the battery cell comprises a porous positive plate, a diaphragm, a negative plate, a positive tab and a negative tab, wherein the porous positive plate, the diaphragm and the negative plate are sequentially stacked to form a lamination structure; the electrolyte injection and gas conduction device is at least 1 hollow pipe which is connected to the packaging shell, one end of the hollow pipe extends into the core cell, and the other end of the hollow pipe is connected with the electrolyte supply device or the gas supply and collection device. The laminated soft-packaged metal-air battery does not need to punch a positive electrode shell, and solves the problem of poor contact of the battery cell at the punching position of the positive electrode shell.

Description

Laminated soft-package metal-air battery and preparation method thereof

Technical Field

The invention relates to the technical field of batteries, in particular to a laminated soft package metal-air battery and a preparation method thereof.

Background

The energy density of the traditional lithium ion battery approaches the theoretical limit and cannot meet the increasing requirements of the modern society. As a novel high-energy battery system, the metal-air battery has the characteristics of high energy density, environmental friendliness and the like, and has a wide application prospect in the fields of portable electronic equipment, power batteries and the like.

At present, people study that most of metal-air batteries adopt a button structure with a punched positive electrode shell, and reaction gas enters the battery from an air hole on the positive electrode shell to participate in reaction. However, the air hole of the positive shell cannot compress the internal battery core well, so that the internal contact of the battery core is poor, and the comprehensive performance of the battery is affected. Meanwhile, the small proportion of the air hole area in the positive electrode shell can influence the diffusion of reaction gas into the battery core, and the large proportion can accelerate the volatilization speed of the electrolyte and influence the service life of the battery. In addition, the energy density and specific energy of the lithium-air battery cell in the button structure are too low to be suitable for basic research and cannot meet commercial requirements.

Disclosure of Invention

The invention aims to provide a laminated soft-package metal-air battery which does not need to be perforated on a positive electrode shell.

In order to solve the technical problems, the invention provides the following technical scheme:

the invention provides a laminated soft-package metal-air battery which is composed of a packaging shell, a battery cell groove formed in the packaging shell, a battery cell arranged in the battery cell groove, electrolyte and an electrolyte injection and gas conduction device, wherein the battery cell is formed by a plurality of battery cells;

the battery cell comprises a porous positive plate, a diaphragm, a negative plate, a positive tab and a negative tab, wherein the porous positive plate, the diaphragm and the negative plate are sequentially stacked to form a lamination structure; the porous positive plate consists of a pair of positive active layers and a first current collector arranged between the pair of positive active layers, and the negative plate consists of a pair of negative active layers and a second current collector arranged between the pair of negative active layers; the first current collector is electrically connected with the positive tab, and the second current collector is electrically connected with the negative tab;

the electrolyte injection and gas conduction device is at least 1 hollow pipe, the hollow pipe is connected to the packaging shell, one end of the hollow pipe extends into the electric core groove, and the other end of the hollow pipe is connected with an electrolyte supply device or a gas supply and collection device.

Further, the packaging outer shell is a flexible packaging film or a metal hard shell, including but not limited to an aluminum plastic film, an aluminum shell, and a stainless steel shell. The depth of the electric core groove is preferably 1-100 mm.

Furthermore, the porous positive plate is N, the diaphragm is 2N-2, and the negative plate is N-1; or the porous positive plate is N-1, the diaphragm is 2N-2, and the negative plate is N; wherein N is more than or equal to 2 and less than or equal to 100.

Further, the current collector is made of a conductive material, and comprises an aluminum mesh, a copper mesh, a titanium mesh, a stainless steel mesh, a carbon mesh, foamed nickel, foamed copper, a copper foil, an aluminum foil and the like; the positive active layer is composed of one or more of Ketjen black, carbon nanotubes, SuperP, graphene, transition metals and oxides and nitrides thereof; the negative active layer is composed of one or more of lithium, zinc and silicon.

Further, the combination of the current collector and the positive and negative active layers includes, but is not limited to, rolling, coating, and sputtering.

Further, the diaphragm is at least one of a glass fiber film, a single layer of PP, a single layer of PE, a PP + ceramic coating, a PE + ceramic coating, a double-layer PP/PE, a three-layer PP/PE/PP and a double-layer PP/PP.

Further, the solvent of the electrolyte may be an ether solvent such as tetraethylene glycol dimethyl ether, triethylene glycol dimethyl ether, or an ionic liquid such as 1-methyl-3-octylimidazole bis (trifluoromethylsulfonyl) -amide, N-methyl-N-butyl-pyrrolidinium bis (trifluoromethylsulfonyl) amide. The lithium salt of the electrolyte may include one or more of lithium perchlorate, lithium bistrifluoromethanesulfonimide, lithium triflate, lithium nitrate. Further, the molar ratio of the solvent to the lithium salt is 1: 1-10: 1.

Furthermore, the anode tab is aluminum, and the cathode tab is nickel; and the current collector is connected with the positive electrode lug/the negative electrode lug through a high-temperature adhesive tape, a conductive adhesive or ultrasonic electric welding.

Further, the gas is one or a mixture of more of air, dry air, pure oxygen and pure carbon dioxide in any proportion; further, the flow rate of the gas is 5-5000 mL/min^-1The pressure is 0.01 to 10 MPa.

The invention also provides a preparation method of the laminated soft package metal-air battery, which comprises the following steps:

(i) cutting the shell material into a preset size, and punching an electric core groove by using a shell punching machine; stacking the porous positive plate, the diaphragm and the negative plate in an argon glove box in sequence to enable a current collector of the porous positive plate to be connected with the positive tab and a current collector of the negative plate to be connected with the negative tab, and welding the current collectors and the negative tab by using an ultrasonic spot welding machine to obtain a battery cell;

(ii) placing the prepared battery core into the battery core groove, placing the plastic package pipe with one sealed end at the position to be sealed of the battery core groove, placing one sealed end of the plastic package pipe outside the package, and enabling the other sealed end of the plastic package pipe to be flush with the edge of the battery core groove; vacuum sealing is carried out on the cell slot in an argon glove box by using a vacuum sealing machine to obtain a battery without being injected with electrolyte;

(iii) and (3) after the battery is clamped by the clamp, removing the seal of the plastic packaging pipe, injecting electrolyte into the battery core, and finishing the battery assembly.

Compared with the prior art, the invention has the beneficial effects that:

1. the laminated soft package metal-air battery provided by the invention can convey or discharge gas to or from the battery cell through the gas conduction device on the packaging shell. During discharging, reaction gas in the cell slot diffuses from the side surface of the current collector of the porous positive plate into the cell, and participates in reaction at the active site of the positive active material; during charging, the generated gas in the electric core is discharged from the side surface of the current collector of the porous positive plate to the electric core groove and is discharged from the guide pipe. The laminated soft-packaged metal-air battery does not need to punch a positive electrode shell, so that the problem of poor contact of the battery cell at the punching position of the positive electrode shell is fundamentally solved; meanwhile, the volatilization of the electrolyte is relieved by the closed cell slot, and the electrolyte can be supplemented for the cell through the electrolyte injection device.

2. The unique structure of the battery core of the laminated soft package metal-air battery enables gas to be freely diffused at the positive electrode of the battery core, and simultaneously overcomes the defect that the positive electrode of the conventional lithium-air battery is required to be arranged at the outer side of the battery core, so that the laminated structure of a plurality of positive plates and negative plates is realized, and the single energy density and the specific energy of the metal-air battery are improved. The laminated soft-package metal-air battery can realize large-scale industrial machine production.

Drawings

Fig. 1 is a schematic structural view of a laminate-type pouch metal-air battery of the present invention;

fig. 2 is a schematic diagram of a cell lamination structure of a lamination type soft package metal-air battery of the present invention;

fig. 3 is a schematic view of the connection of the porous positive plate and the positive tab of the laminated soft-packed metal-air battery of the present invention;

fig. 4 is a schematic diagram of the negative plate and negative tab connections of a laminated soft pack metal-air battery of the present invention;

fig. 5 is a charge-discharge curve of a laminated soft-package lithium-oxygen battery based on the invention, wherein the current collector of the porous positive plate is foamed nickel;

fig. 6 is a discharge curve of a laminated soft-package lithium-oxygen battery based on the invention, wherein the current collector of the porous positive plate is carbon paper;

the reference numbers in the figures illustrate: 1. a packaging housing; 11. an electrical core slot; 2. an electric core; 21. a porous positive plate; 211. a positive electrode active layer; 212. a first current collector; 22. a negative plate; 221. a negative electrode active layer; 222. a second current collector; 23. a diaphragm; 24. a positive tab; 25. a negative tab; 3. electrolyte injection and gas conduction means.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Example 1

Referring to fig. 1, the laminated soft package metal-air battery of the present invention comprises a package housing 1, a cell slot 11 formed inside the package housing 1, a cell 2 disposed in the cell slot 11, an electrolyte, and an electrolyte injection and gas conduction device 3.

The packaging shell 1 can be a soft packaging film or a metal hard shell, including but not limited to an aluminum plastic film, an aluminum shell, a stainless steel shell. The depth of the electric core groove 11 is preferably 1-100 mm. In the embodiment, the packaging shell 1 is made of an aluminum-plastic film with the size of 17.7cm by 5.75 cm; the size of the electric core groove 11 is 8.35cm 4.75cm, the depth is 2mm, and the sealing edge width is 0.5 cm.

Referring to fig. 2-4, the battery cell 2 includes a porous positive plate 21, a separator 23, a negative plate 22, a positive tab 24, and a negative tab 25, wherein the porous positive plate 21, the separator 23, and the negative plate 22 are sequentially stacked to form a lamination structure. The porous positive plate 21 is N, the diaphragm 23 is 2N-2, and the negative plate 22 is N-1; or the porous positive plate 21 is N-1, the diaphragm 23 is 2N-2, and the negative plate 22 is N; wherein N is more than or equal to 2 and less than or equal to 100. In this example, the number of the porous positive electrode sheets 21 is 2 (N-2), and the number of the negative electrode sheets 22 is 1 (N-1).

In the present invention, the porous positive electrode sheet 21 is composed of a pair of positive electrode active layers 211 and a first current collector 212 disposed between the pair of positive electrode active layers 211, and the negative electrode sheet 22 is composed of a pair of negative electrode active layers 221 and a second current collector 222 disposed between the pair of negative electrode active layers 221; first current collector 212 is electrically connected to positive tab 24 and second current collector 222 is electrically connected to negative tab 25. Wherein, the positive active layer 211 may be composed of one or more of the group consisting of ketjen black, carbon nanotube, SuperP, graphene, transition metal and oxide and nitride thereof; the negative electrode active layer 221 may be composed of one or more of lithium, zinc, and silicon. The current collector is made of conductive materials, and comprises an aluminum net, a copper net, a titanium net, a stainless steel net, a carbon net, foamed nickel, foamed copper, a copper foil, an aluminum foil and the like. The combination of the current collector with the positive electrode active layer 211 and the negative electrode active layer 221 includes, but is not limited to, rolling, coating, and sputtering.

In this embodiment, the current collector of the porous positive electrode sheet is made of foamed nickel, the positive electrode active material is made of SuperP, and the size of the porous positive electrode sheet is 8.0cm by 4.65 cm. The thickness of the foamed nickel is 0.3mm, and the porosity is 75%. The SuperP positive electrode is formed by rolling a film and cutting pieces by slurry obtained by mixing 12% of polytetrafluoroethylene emulsion and SuperP according to the mass ratio of 15:85, and the surface density is 6 mg-cm^-2. The negative plate of the embodiment is composed of a current collector copper foil of the negative plate and a negative active material lithium plate pressed on the copper foil, and the size of the negative plate is 8.0cm by 4.45 cm. The thickness of copper foil is 8um, and the thickness of lithium piece is 0.25 mm. The positive electrode lug is an aluminum lug, and the negative electrode lug is a nickel lug.

In the present invention, the separator 23 may be at least one selected from a glass fiber film, a single layer PP, a single layer PE, a PP + ceramic coating, a PE + ceramic coating, a double layer PP/PE, a triple layer PP/PE/PP, and a double layer PP/PP. In this example, the separator 23 was a whatman G/FA glass fiber membrane having a size of 8.3cm by 4.65cm and a number of 2(2N-2 ═ 2).

In the present invention, the solvent of the electrolyte may be an ether-type solvent such as tetraethylene glycol dimethyl ether, triethylene glycol dimethyl ether, or an ionic liquid such as 1-methyl-3-octylimidazole bis (trifluoromethylsulfonyl) -amide, N-methyl-N-butyl-pyrrolidinium bis (trifluoromethylsulfonyl) amide. The lithium salt of the electrolyte may include one or more of lithium perchlorate, lithium bistrifluoromethanesulfonimide, lithium triflate, lithium nitrate. In this embodiment, the electrolyte solvent is tetraethylene glycol dimethyl ether, the lithium salt is lithium bistrifluoromethylsulfonyl imide (LiTFSI), and the concentration of the lithium salt is 1M.

The electrolyte injection and gas conduction device 3 is at least 1 hollow pipe, which is connected to the packaging shell 1, one end of the hollow pipe extends into the electric core groove 11, and the other end is connected with an electrolyte supply device or a gas supply and collection device (not shown). In this embodiment, electrolyte injection and gas conduction device 3 chooses for use two plastic envelope pipes, internal diameter 1mm, external diameter 2mm, and length is 1 cm.

In this example, the battery was assembled according to the following procedure. Cutting the aluminum plastic film into 17.7cm by 5.75cm, and punching a cell slot with 8.35cm by 4.75cm by 2mm by using a shell punching machine. In an Ar glove box, the prepared porous positive plate, the diaphragm and the prepared negative plate with the specifications as described above are stacked in the order of the negative plate, the porous positive plate, the diaphragm, the negative plate, the diaphragm, the porous positive plate, the diaphragm and the negative plate, the foamed nickel is connected with the aluminum positive tab, the copper foil is connected with the nickel negative tab, and the copper foil is welded by an ultrasonic spot welding machine to finally prepare the battery cell. And placing the prepared battery cell into a battery cell, placing two plastic packaging pipes with one sealed ends at the diagonal positions of the battery cell to be sealed, placing one sealed end of each plastic packaging pipe outside the flexible package, and flushing the other end of each plastic packaging pipe with the edge of the battery cell. And (4) carrying out vacuum sealing on the cell slot in an argon glove box by using a vacuum sealing machine to obtain the battery without being injected with the electrolyte. And (3) after the battery is clamped by a clamp, removing the seal of the plastic packaging tube, injecting 2mL of electrolyte into the battery cell by using an injector, and finishing the assembly of the battery.

The cell prepared in example 1 was tested under the following conditions: the reaction gas is oxygen (21.9%) in argon, and the mixed gas is pumped into a cell tank from a conduit by a peristaltic pump at a flow rate of 1.5 mL/min^-1. After the battery is ventilated for 12 hoursThe charge-discharge cycle test was started, and the discharge cutoff voltage was 2V and the charge cutoff voltage was 4.5V. The discharge was performed with a current of 10mA, and then the charge was performed with a current of 10 mA.

The test results are shown in fig. 5, from which it can be seen that the battery discharge capacity is 526mAh, the voltage during discharge is 2.63V, and the charge capacity is 539 mAh.

Example 2

Example 2 is essentially the same as example 1, except that:

the current collector of the porous positive plate is carbon paper, and is fixed by a PET (polyethylene terephthalate) termination adhesive tape after being connected with an aluminum tab. The cell was discharged at 10mA current. The test results are shown in fig. 6, and the discharge capacity of the battery is 1313 mAh.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims

1. The laminated soft package metal-air battery is characterized by comprising a packaging shell, a cell groove formed in the packaging shell, a cell arranged in the cell groove, electrolyte and an electrolyte injection and gas conduction device, wherein the cell groove is formed in the packaging shell; the electrolyte injection and gas conduction device is used for supplementing electrolyte in the battery cell and conveying or discharging gas in the battery cell groove;

the electrolyte injection and gas conduction device is at least 1 hollow pipe, the hollow pipe is connected to the packaging shell, one end of the hollow pipe extends into the electric core groove, and the other end of the hollow pipe is connected with an electrolyte supply device or a gas supply and collection device;

the porous positive plate is N, the diaphragm is 2N-2, and the negative plate is N-1; or the porous positive plate is N-1, the diaphragm is 2N-2, and the negative plate is N; wherein N is more than or equal to 2 and less than or equal to 100;

the first current collector is made of foamed nickel or foamed copper; during discharging, reaction gas in the cell slot diffuses into the cell from the side surface of the first current collector, and participates in reaction at an active site of the positive electrode active layer; during charging, generated gas in the electric core is discharged to the electric core groove from the side surface of the first current collector; the second current collector is composed of an aluminum net, a copper net, a titanium net, a stainless steel net, a carbon net, foamed nickel, foamed copper, a copper foil or an aluminum foil.

2. The laminated soft-package metal-air battery as claimed in claim 1, wherein the packaging shell is a soft packaging film or a hard metal shell, and the depth of the battery cell groove is 1-100 mm.

3. The laminate-type pouch metal-air battery according to claim 1,

the positive active layer is composed of one or more of Ketjen black, carbon nanotubes, SuperP, graphene, transition metals and oxides and nitrides thereof;

the negative active layer is composed of one or more of lithium, zinc and silicon.

4. The laminated pouch metal-air battery as recited in claim 1 wherein the current collector is combined with the positive and negative active layers by rolling, coating, or sputtering.

5. The laminate-type pouch metal-air battery according to claim 1, wherein the separator is at least one of a fiberglass film, a single layer of PP, a single layer of PE, a PP + ceramic coating, a PE + ceramic coating, a double layer of PP/PE, a triple layer of PP/PE/PP, and a double layer of PP/PP.

6. The laminate-type pouch metal-air battery of claim 1, wherein the electrolyte solvent comprises tetraglyme, triglyme, 1-methyl-3-octylimidazolium bis (trifluoromethylsulfonyl) -amide, and N-methyl-N-butyl-pyrrolidinium bis (trifluoromethylsulfonyl) amide; the lithium salt of the electrolyte comprises one or more of lithium perchlorate, lithium bistrifluoromethanesulfonimide, lithium trifluoromethanesulfonate and lithium nitrate; the molar ratio of the solvent to the lithium salt is 1: 1-10: 1.

7. The laminate-type pouch metal-air battery according to claim 1, wherein the positive tab is aluminum and the negative tab is nickel; and the current collector is connected with the positive electrode lug/the negative electrode lug through a high-temperature adhesive tape, a conductive adhesive or ultrasonic electric welding.

8. The laminate type soft package metal-air battery according to claim 1, wherein the gas is a mixture of one or more of air, oxygen and carbon dioxide in any proportion; the flow rate of the gas is 5-5000 mL/min^-1The pressure is 0.01 to 10 MPa.

9. The method for manufacturing a laminate-type pouch metal-air battery according to any one of claims 1 to 8, characterized by comprising the steps of: