阅读说明：本技术 一种可拉伸的柔性金属空气电池 (Stretchable flexible metal-air battery ) 是由 谈鹏 丁毓琪 于 2019-09-24 设计创作，主要内容包括：本发明涉及一种可拉伸的柔性金属空气电池。包括金属空气电池基体和伸缩管；金属空气电池基体呈弹簧状位于伸缩管内,金属空气电池基体的两端分别为负极集流体和正极集流体；金属空气电池基体包括锌金属丝,锌金属丝上由内至外包裹着凝胶电解质和柔性空气电极；将线状金属空气电池基体嵌入伸缩管内,伸缩管为电池提供支撑,管壁上的透气孔利于氧气的传输；而且,伸缩管保障了电池的延展性,可适用较大程度的拉伸。柔性金属空气电池的原始长度L为5～6cm,柔性金属空气电池的输出电压为1.25～1.28V,充电电压为1.98～2.01V；在拉伸过程中保持输出电压稳定,柔性金属空气电池的最大拉伸程度为125～200%。(The invention relates to a stretchable flexible metal-air battery. Comprises a metal-air battery matrix and a telescopic pipe; the metal-air battery matrix is positioned in the telescopic pipe in a spring shape, and a negative current collector and a positive current collector are respectively arranged at two ends of the metal-air battery matrix; the metal-air battery matrix comprises a zinc metal wire, and the zinc metal wire is wrapped with a gel electrolyte and a flexible air electrode from inside to outside; embedding a linear metal-air battery matrix into a telescopic pipe, wherein the telescopic pipe provides support for the battery, and air holes in the pipe wall are favorable for oxygen transmission; moreover, the extension tube ensures the ductility of the battery and is suitable for stretching to a greater degree. The original length L of the flexible metal-air battery is 5-6 cm, the output voltage of the flexible metal-air battery is 1.25-1.28V, and the charging voltage is 1.98-2.01V; the output voltage is kept stable in the stretching process, and the maximum stretching degree of the flexible metal-air battery is 125-200%.)

1. A stretchable flexible metal-air cell, characterized in that: comprises a metal-air cell base body and a telescopic pipe (24); the metal-air battery matrix is positioned in the telescopic pipe in a spring shape, and the two ends of the metal-air battery matrix are respectively provided with a negative current collector (21) and a positive current collector (22) for collecting current;

the metal-air battery matrix comprises a zinc metal wire (11), wherein the zinc metal wire (11) is wrapped with a gel electrolyte (12) and a flexible air electrode (13) from inside to outside;

the original length L of the flexible metal-air battery is 5-6 cm, the number n of spirals of the metal-air battery matrix is 20-25, and the maximum stretching distance x is 0.3-0.5 cm; the output voltage of the flexible metal-air battery is 1.25-1.28V, and the charging voltage is 1.98-2.01V; the output voltage is kept stable in the stretching process, and the maximum stretching degree of the flexible metal-air battery is nx/L multiplied by 100 percent, namely 125-200 percent.

2. The method for preparing the stretchable flexible metal-air battery according to claim 1, characterized by comprising the following steps:

(1) preparation of gel electrolyte

Dissolving 1g of polyvinyl alcohol (PVA) in 8mL of deionized water at 80 ℃, uniformly stirring, adding 2mL of 10-20M potassium hydroxide (KOH) aqueous solution, and continuously stirring for 1-2 hours to obtain a gel electrolyte;

(2) preparation of Flexible air electrode

Mixing 1-4 mg of cobaltosic oxide (Co)₃O₄) Uniformly mixing nano particles, 0.5-2 mg of conductive carbon powder, 0.5-2 mg of polytetrafluoroethylene binder and 0.5-1 mL of absolute ethyl alcohol to form slurry, uniformly coating the slurry on carbon cloth by scraping, and drying for 12 hours at the temperature of 60 ℃; cobaltosic oxide (Co)₃O₄) The nano particles are used as active substances, and the loading amount of the active substances on the carbon cloth is 1-4 mg/cm²(ii) a Obtaining a flexible air electrode (13);

(3) assembled metal-air battery matrix

(3.1) putting the zinc metal wire into PVA/KOH gel electrolyte for fully soaking for 1-2 min, taking out, enabling the gel electrolyte to uniformly coat the zinc metal wire, freezing for 8 hours at the temperature of-10 ℃, unfreezing at room temperature to enhance physical crosslinking, and enabling the thickness of the gel electrolyte on the zinc metal wire to be 0.5-1 mm to obtain an assembly;

(3.2) uniformly wrapping the flexible air electrode on the assembly to obtain a zinc-air electrode substrate;

(4) assembled battery

(4.1) winding the zinc-air electrode substrate into a spring shape;

(4.2) air holes are uniformly distributed on the extension tube (24);

(4.3) embedding the spring-shaped zinc-air electrode substrate into the telescopic pipe (24), wherein two ends of the zinc-air electrode substrate are respectively positioned outside the telescopic pipe (24), and a negative current collector (21) and a positive current collector (22) are respectively arranged at the two ends of the zinc-air electrode substrate, so that the flexible metal-air battery is obtained.

3. The method of claim 2, wherein: the cobaltosic oxide (Co)₃O₄) The purity of the nano-particles is more than 99.9%, and the average particle size is 10-50 nm, and the nano-particles are used as active substances.

4. The method of claim 2, wherein: the zinc metal wire is 99% pure and 1-2 mm in diameter.

5. The method of claim 2, wherein: the telescopic pipe (24) is made of Polyurethane (PU) or polyvinyl chloride (PVC) and has a pipe diameter of 0.8-1 cm.

6. The method of claim 2, wherein: the aperture of the air holes is 1-2 mm, and the sum of the areas of the air holes is 50-70% of the surface area of the telescopic pipe (24).

Technical Field

The invention belongs to the field of battery application, and particularly relates to a stretchable flexible metal-air battery which can provide power supply for wearable electronic equipment such as a smart watch and a sports bracelet.

Background

Along with the development of wearable electronic equipment such as intelligent wrist-watch, motion bracelet, flexible electrical power generating system with the ability of stretching and bending is the key of guaranteeing its normal work. Although flexible lithium ion batteries and supercapacitors have become a focus of research, the limited energy density has greatly limited the range of electronic devices. The metal air adopts metal and oxygen in the air as active substances, has extremely high energy density, and can be used for long-time continuous functions of electronic equipment. Moreover, the zinc-air battery is mature in development, low in cost, safe and environment-friendly. In order to meet the requirements of flexible electronic devices, a series of researches have been carried out in recent years on flexible metal-air batteries, and the structures of the flexible metal-air batteries can be roughly divided into two types:

the first type is a layered structure: the metal and active substances loaded on a flexible current collector are used as a metal electrode and an air electrode, and are separated by an electrolyte membrane to form a sandwich structure (nat. Commun., 2015, 6, 7892; Small2018, 14, 1800225).

The second type is a linear structure: a metal wire is used as a metal electrode, a circle of electrolyte membrane is wound on the surface of the metal wire, and finally, a flexible current collector loaded with active substances is wrapped to be used as an air electrode, so that a cable-shaped structure is formed (adv. mater, 2015, 27,1396; Small, 2016, 12, 3101).

Although both of the above-described cell structures impart better flexibility to the cell by employing a flexible electrolyte membrane and a current collector, the stretchability is limited. In the wire structure, by using a metal zinc spring as a metal electrode, a 10% elongation can be achieved (CN 105244565). In the layered structure, although the degree of elongation is increased to 100% by the copper spring connection by decomposing the metallic lithium into small pieces (j. mater. chem. a, 2016, 4, 13419), the ineffective mass and volume of the battery are increased due to the introduction of the copper spring and the like, and the actual energy density is reduced. Therefore, in order to meet the bending and stretching requirements accompanied by wearable electronic devices in use, it is urgently required to develop a flexible metal-air battery which has high energy density and can achieve large stretching.

Disclosure of Invention

The invention aims to provide a stretchable flexible metal-air battery to achieve the aims of large stretching and flexibility.

A stretchable flexible metal-air battery includes a metal-air battery base 23 and an extension tube 24; the metal-air battery matrix is positioned in the telescopic pipe in a spring shape, and the two ends of the metal-air battery matrix are respectively provided with a negative current collector 21 and a positive current collector 22 for collecting current;

the metal-air battery matrix comprises a zinc metal wire 11, wherein the zinc metal wire 11 is wrapped with a gel electrolyte 12 and a flexible air electrode 13 from inside to outside;

the original length L of the flexible metal-air battery is 5-6 cm, the number n of spirals of the metal-air battery matrix is 20-25, and the maximum stretching distance x is 0.3-0.5 cm; the output voltage of the flexible metal-air battery is 1.25-1.28V, and the charging voltage is 1.98-2.01V; the output voltage is kept stable in the stretching process, and the maximum stretching degree of the flexible metal-air battery is nx/L multiplied by 100 percent, namely 125-200 percent.

The preparation operation steps of the stretchable flexible metal-air battery are as follows:

(1) preparation of gel electrolyte

Dissolving 1g of polyvinyl alcohol (PVA) in 8mL of deionized water at 80 ℃, uniformly stirring, adding 2mL of 10-20M potassium hydroxide (KOH) aqueous solution, and continuously stirring for 1-2 hours to obtain a gel electrolyte;

(2) preparation of Flexible air electrode

Mixing 1-4 mg of cobaltosic oxide (Co)₃O₄) Uniformly mixing nano particles, 0.5-2 mg of conductive carbon powder, 0.5-2 mg of polytetrafluoroethylene binder and 0.5-1 mL of absolute ethyl alcohol to form slurry, uniformly coating the slurry on carbon cloth by scraping, and drying for 12 hours at the temperature of 60 ℃; cobaltosic oxide (Co)₃O₄) The nano particles are used as active substances, and the loading amount of the active substances on the carbon cloth is 1-4 mg/cm²(ii) a Obtaining a flexible air electrode (13);

(3) assembled metal-air battery matrix

(3.1) putting the zinc metal wire into PVA/KOH gel electrolyte for fully soaking for 1-2 min, taking out, enabling the gel electrolyte to uniformly coat the zinc metal wire, freezing for 8 hours at the temperature of-10 ℃, unfreezing at room temperature to enhance physical crosslinking, and enabling the thickness of the gel electrolyte on the zinc metal wire to be 0.5-1 mm to obtain an assembly;

(3.2) uniformly wrapping the flexible air electrode on the assembly to obtain a zinc-air electrode substrate;

(4) assembled battery

(4.1) winding the zinc-air electrode substrate into a spring shape;

(4.2) air holes are uniformly distributed on the extension tube 24;

(4.3) embedding the spring-shaped zinc-air electrode substrate into the telescopic pipe 24, wherein two ends of the zinc-air electrode substrate are respectively positioned outside the telescopic pipe 24, and the two ends are respectively a negative current collector 21 and a positive current collector 22, so as to obtain the flexible metal-air battery.

The technical scheme for further limiting is as follows:

the cobaltosic oxide (Co)₃O₄) The purity of the nano-particles is more than 99.9%, and the average particle size is 10-50 nm, and the nano-particles are used as active substances.

The zinc metal wire is 99% pure and 1-2 mm in diameter.

The telescopic pipe 24 is made of Polyurethane (PU) or polyvinyl chloride (PVC) and has a pipe diameter of 0.8-1 cm.

The aperture of the air holes is 1-2 mm, and the sum of the areas of the air holes is 50-70% of the surface area of the telescopic pipe (24).

The beneficial technical effects of the invention are embodied in the following aspects:

1. the metal-air battery matrix adopts a linear structure, so that the interface separation phenomenon caused by the fact that the mechanical properties of three layers of materials are different in the bending process of the layered structure can be avoided, and the stability of the interface can be kept better. The telescopic pipe is light in weight, has small influence on the total mass of the battery, and is more beneficial to obtaining high energy density. Embedding a linear metal-air battery matrix into the bent part of a telescopic pipe, wherein the telescopic pipe provides support for the battery, and air holes in the pipe wall are favorable for oxygen transmission; moreover, the extension tube ensures the ductility of the battery and is suitable for stretching to a greater degree.

2. The metal electrode adopts metal zinc, and the active material of the air electrode adopts cobaltosic oxide (Co)₃O₄) The zinc-air battery charge and discharge formed by the nano particles as the catalyst for oxygen reduction and oxygen precipitationThe electric reaction is as follows:

the output voltage can reach more than 1.2V, the charging voltage is about 2.0V, and the battery can be charged and discharged for use for many times.

3. The original length L of the flexible metal-air battery is 5-6 cm, and the maximum stretching degree is 125-200%. The output voltage is 1.25-1.28V, the charging voltage is 1.98-2.01V, and the output voltage is kept stable in the stretching process. The power supply can be used as a power supply of wearable flexible electronic equipment such as a smart watch, a sports bracelet and the like.

Drawings

Fig. 1 is a perspective view of a metal-air battery substrate.

Fig. 2 is a cross-sectional view of a metal-air cell substrate.

11-metal wire; 12-a gel electrolyte; 13-Flexible air electrode.

Fig. 3 is a schematic diagram of the original state of the stretchable flexible metal-air battery, wherein the length is L, and the number of intervals is n.

Fig. 4 is a schematic diagram of the stretching state of the stretchable flexible metal-air battery, wherein the stretching distance is x'.

Fig. 5 is a schematic diagram of the stretchable flexible metal-air battery in a fully stretched state, wherein the stretching distance is x.

Wherein 21-negative current collector; 22-positive current collector; 23-metal-air cell substrate; 24-telescoping tube. The maximum elongation of the cell was found to be nx/L × 100%.

Detailed Description

The invention will now be further described, by way of example, with reference to the accompanying drawings.