CN216054799U

CN216054799U - Zinc electrode protected by fiber membrane

Info

Publication number: CN216054799U
Application number: CN202120404411.2U
Authority: CN
Inventors: 孙予罕; 钱婧; 王慧; 曾高峰; 范义秋; 徐庆; 杨阳; 赵唱; 刘一健
Original assignee: Shanghai Cluster Rui Low Carbon Energy Technology Co ltd; Shanghai Advanced Research Institute of CAS
Current assignee: Shanghai Cluster Rui Low Carbon Energy Technology Co ltd; Shanghai Lanze Energy Technology Co ltd
Priority date: 2021-02-24
Filing date: 2021-02-24
Publication date: 2022-03-15
Anticipated expiration: 2031-02-24

Abstract

The utility model discloses a zinc electrode protected by a fiber membrane, which is characterized by comprising the fiber membrane covering two sides of a zinc sheet. The preparation method comprises the following steps: two fiber films are attached to two surfaces of the zinc sheet, and then the side fiber films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber films. The preparation method has the advantages of simple process, low cost and replaceable machinery, and the obtained zinc sheet protected by the fiber membrane reduces the influence of zinc dendrites on the air electrode, and has good application prospect in the related fields of electro-catalysis and secondary zinc-air batteries.

Description

Zinc electrode protected by fiber membrane

Technical Field

The utility model relates to a zinc electrode, a preparation method and application, which are mainly used in the technical field of electrocatalysis under alkaline conditions, in particular to the technical field of zinc-air batteries, and belong to the technical field of preparation and application of energy materials.

Background

Along with the rapid development of economy, the demand of people for various power sources is also increasing. Therefore, the development of energy storage batteries with high specific energy and clean and safe performance is an important requirement for social development. The zinc-air battery is a metal-air battery which takes metal zinc as a negative electrode and oxygen as a positive electrode active material. The theoretical energy density of the zinc-air battery is high, is 1350 Wh/kg-1 and is about 5 times that of a commercial lithium battery. The zinc-air battery also has the advantages of low cost, good safety performance, simple battery structure and the like, and is widely concerned as a low-cost green sustainable energy source. Among them, the rechargeable zinc-air battery is the focus of the current zinc-air battery research and has important significance for promoting the large-scale application thereof. Dendritic zinc crystals (zinc dendrites) are produced at the zinc negative electrode during charging during cycling of the zinc-air battery. The growth length of the zinc dendrite grows exponentially along with the charging time, so that the zinc dendrite not only can pierce through a diaphragm to cause a battery short circuit, but also can fall off from the surface of a zinc electrode to cause the attenuation of the battery capacity, and the cycle life of the battery is influenced.

The zinc electrodes most widely used at present are zinc foils and zinc pastes, but regardless of the zinc material used as the negative electrode, it is difficult to prevent the zinc dendrite problem occurring during long-term cycling. Therefore, there is a need to develop a zinc electrode suitable for rechargeable zinc-air batteries, which can improve the utilization rate and reversible cyclicity of the metal zinc electrode, and reduce the energy loss of the secondary zinc-air battery, so as to meet the increasingly developed use requirements of rechargeable zinc-air batteries.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is as follows: the chargeable and dischargeable zinc-air battery has the problems of short circuit and the like caused by the dendritic growth of a zinc electrode.

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

the fiber membrane protected zinc electrode is characterized by comprising fiber membranes covering two sides of a zinc sheet.

Preferably, the fibrous membrane is a cotton fibrous membrane.

The fiber membrane is prepared by sulfonating natural cellulose.

The preparation method of the zinc electrode comprises the following steps: two fiber films are attached to two surfaces of the zinc sheet, and then the side fiber films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber films.

Preferably, the zinc sheet is prepared by sanding, then ultrasonically cleaning by using ethanol and then drying at room temperature.

The zinc electrode protected by the fiber membrane can be applied to chargeable and dischargeable zinc-air batteries.

The preparation method has the advantages of simple process, low cost and replaceable machinery, and the obtained zinc sheet protected by the fiber membrane reduces the influence of zinc dendrites on the air electrode, and has good application prospect in the related fields of electro-catalysis and secondary zinc-air batteries.

Drawings

FIG. 1 is a schematic diagram of a zinc electrode provided by the present invention;

FIG. 2 is a scanning electron microscope topography of a fibrous film of the zinc-protected electrode used in example 1;

fig. 3 shows the charge and discharge performance of the fiber membrane-protected zinc electrode prepared in example 1 for a zinc-air battery.

Detailed Description

In order to make the utility model more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

As shown in fig. 1, the fiber membrane protected zinc electrode provided by the utility model comprises fiber membranes 2 coated on both sides of a zinc sheet 1. The fiber membrane 2 is a cotton fiber membrane.

Example 1

A preparation method of a fiber membrane protected zinc electrode comprises the following steps:

step 1): polishing a zinc sheet by using sand paper, ultrasonically cleaning the zinc sheet in ethanol, and drying the zinc sheet at room temperature;

step 2): two fiber films are attached to two sides of the zinc sheet, and the side films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber films.

Fig. 2 is a scanning electron microscope topography of the fiber film adopted in the embodiment, and a field emission electron microscope is used to perform microstructure characterization on the fiber film material of the present invention. The fiber film can be seen to be in a net structure under an electron microscope.

Fig. 3 is a graph showing the charge and discharge performance of the zinc electrode prepared in this example for a zinc-air battery. The zinc electrode plate is applied to the cycling charge-discharge stability of the zinc-air battery. The electrolyte used for the test was a 9M KOH solution. The current density of charging is 5mA cm^-2And charging for 5min, and then performing discharge test at the same current density for 5min, so as to perform cyclic charge-discharge test under the condition. The result shows that the first circle charging voltage is about 2.24V, the discharging voltage is about 1.20V, the first circle energy efficiency is 53.5%, and the stable charging and discharging is kept for 3500 circles.

Example 2

A preparation method of a zinc electrode protected by a polytetrafluoroethylene film comprises the following steps:

step 2): two pieces of polytetrafluoroethylene films are attached to two surfaces of the zinc sheet, and the side films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber films.

Example 3

A preparation method of a zinc electrode protected by parchment paper comprises the following steps:

step 2): two pieces of parchment paper are pasted on two surfaces of the zinc sheet, and the side films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber film.

Example 4

A preparation method of a zinc electrode protected by a polypropylene film comprises the following steps:

step 2): two polypropylene films are attached to two surfaces of the zinc sheet, and the side films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber film.

Example 5

A preparation method of a zinc electrode protected by a polypropylene/polyethylene/polypropylene film comprises the following steps:

step 2): two polypropylene/polyethylene/polypropylene films are attached to two surfaces of the zinc sheet, and the side films are tightly sealed by a heat sealing machine to obtain the zinc sheet protected by the fiber film.

Comparative example 1

A preparation method of a common zinc electrode comprises the following steps:

step 1): and (3) polishing the zinc sheet by using sand paper, ultrasonically cleaning the zinc sheet in ethanol, and drying the zinc sheet at room temperature.

The zinc electrode samples of example 1, example 5 and comparative example 1 were taken for zinc-air cell assembly and tested for electrochemical performance, galvanostatic test, respectively. The current density of charging is 5mA cm^-2And charging for 5min, then performing a discharge test at the same current density for 5min, and performing a cyclic charge and discharge test under the condition to obtain a charge and discharge performance curve. The charging voltage of the first circle of the corresponding battery in the embodiment 1 is about 2.24V, the discharging voltage is about 1.20V, and the energy efficiency of the first circleThe rate is 53.5%, and stable charging and discharging is kept for 3500 circles. Compared with the electrode sample of example 1, the battery corresponding to comparative example 1 has the first-cycle discharge voltage of 1.226V, the charge voltage of about 2.326V and the first-cycle energy efficiency of 50.0%, but the charge-discharge cycle only reaches about 2000 cycles, the discharge voltage gradually decreases, and the energy efficiency of the battery decreases to 33.4% when the cycle reaches 2000 cycles. Compared with the electrode sample in the example 1, the first-cycle discharge voltage of the battery corresponding to the example 5 reaches 1.181V, the charge voltage is about 2.179V, and the first-cycle energy efficiency is 54.1%, but the charge-discharge cycle only reaches about 1600 cycles, the discharge voltage gradually decreases, and the energy efficiency of the battery decreases to 36.7% when the battery is cycled to 1600 cycles. Thus, the zinc electrode of example 1 exhibited better stability and utilization than the zinc electrodes of example 5 and comparative example 1, and the electrochemical performance of the corresponding zinc-air battery was more excellent. The utility model can improve the utilization rate of the zinc electrode, reduce the influence of zinc dendrite on the air electrode and optimize the cycle operation life of the zinc electrode and the secondary zinc-air battery by protecting the zinc electrode by using the fiber membrane.

Claims

1. The zinc electrode protected by the fiber membrane is characterized by comprising the fiber membrane (2) coated on two sides of a zinc sheet (1); the fiber film (2) is a cotton fiber film.