CN110854430A

CN110854430A - Simple method for preparing high-performance solid polymer electrolyte

Info

Publication number: CN110854430A
Application number: CN201911156265.XA
Authority: CN
Inventors: 程佳明; 童永芬; 曹晓燕
Original assignee: Nanchang Hangkong University
Current assignee: Nanchang Hangkong University
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2020-02-28

Abstract

The invention takes BPADE, ED-2003 and LiTFSI as raw materials and obtains the all-solid polymer electrolyte membrane by a simple thermal crosslinking method. The method has the advantages of simple operation, easy control of reaction conditions, easy industrial large-scale production, and excellent independent moldability, high ionic conductivity and good electrochemical performance of the prepared polymer electrolyte, and can be used in lithium batteries. When the molar ratio of the two reactants of BPADE and ED2003 is 2:1 and the oxygen-lithium ratio is 16, the temperature conductivity value of the solid polymer electrolyte is 7.48 multiplied by 10^‑5S·cm^‑11.33X 10 at 95 DEG C^‑3S·cm^‑1. The solid polymer electrolyte has good flexibility, safe and stable use and good application prospect.

Description

Simple method for preparing high-performance solid polymer electrolyte

Technical Field

The invention relates to a simple method for preparing a high-performance solid polymer electrolyte, and particularly belongs to the technical field of electrolyte materials in lithium ion energy storage batteries.

Background

The electrolyte of the lithium ion battery is a bridge connecting the anode and the cathode of the battery and plays a role in transmitting lithium ions. In addition to the factors of electrode materials, the material properties of the electrolyte affect the performance of the lithium ion battery, such as specific energy, safety performance, cycle performance, rate charge and discharge performance, and cost. Because of the flammability and low ignition point of the liquid electrolyte of the lithium ion battery, the development of the battery is severely limited due to the safety problems of easy leakage, even explosion and the like.

The concept of polymer electrolytes was first proposed in 1973 and was first applied to commercial lithium ion batteries by Sony corporation twenty years later. Thereafter, polymer electrolytes have been developed in several stages, from solvent-free polymer electrolytes to addition to plasticizing systems, i.e., addition of small amounts of liquid electrolytes to solvent-free polymer electrolytes, to gel polymer electrolytes, rubbery polymer electrolytes, and composite electrolytes, including composite electrolytes with ceramic nanoparticles added, and the like. The all-solid polymer electrolyte avoids the risk of battery leakage since it does not contain flammable liquid solvents. Has excellent safety performance. In addition, the polymer electrolyte has good flexibility and mechanical stability. Meanwhile, the polymer electrolyte also has the advantages of light weight, good viscoelasticity, easy film formation and the like, so that the polymer electrolyte has wide application prospect. With the continuous progress of electrode materials, polymer electrolytes have become key materials for determining the performance of solid polymer lithium ion batteries.

However, the matrix of the all-solid-state polymer electrolyte is a solid polymer, so that the migration of ions is limited to a certain extent, the room-temperature conductivity of the all-solid-state polymer electrolyte is low, and the charge-discharge specific capacity of the all-solid-state lithium ion battery is limited, so that the ion conductivity of the solid polymer electrolyte is improved, and the preparation of the ultrathin and flexible solid polymer electrolyte with high conductivity is a main problem to be solved by the invention.

The invention takes 2, 2-bis (4-epoxypropoxyphenyl) propane (BPADE) and polyamine ether (ED-2003) as raw materials, and obtains the all-solid polymer electrolyte membrane by a simple thermal crosslinking method, wherein the polyether amine endows the electrolyte with the ion transmission performance, and the 2, 2-bis (4-epoxypropoxyphenyl) propane ensures the better mechanical performance of the electrolyte. The all-solid-state polymer electrolyte membrane with good electrochemical performance and excellent independent film-forming performance is obtained by a simple process which is easy to realize industrial large-scale production.

Disclosure of Invention

The invention aims to provide a simple preparation method of a cross-linked polymer electrolyte, which comprises the following steps:

step 1: uniformly mixing 2, 2-bis (4-epoxypropoxyphenyl) propane (BPADE), polyamine ether (ED-2003) and lithium bistrifluoromethanesulfonimide (LiTFSI) in proportion, dissolving into an acetonitrile solvent, and then stirring for 3 hours on an intelligent constant-temperature timing magnetic stirrer to completely dissolve the mixture to obtain a transparent mixed solution;

the molar ratio of the 2, 2-bis (4-epoxypropoxyphenyl) propane to the polyether diamine to the lithium bistrifluoromethanesulfonylimide is as follows: 1-3: 1: 1.6-4.8;

step 2: and (3) dripping the mixed solution on a polytetrafluoroethylene mould by using a disposable rubber dropper, volatilizing the solvent in the polytetrafluoroethylene mould at normal temperature until the mixed solution is in a sol state, and then heating and curing at 80-120 ℃ to obtain the solid polymer electrolyte.

The invention has the beneficial effects that: the method has the advantages of simple operation, easy control of reaction conditions, easy industrial large-scale production, and excellent independent moldability of the prepared polymer electrolyte, high ionic conductivity and good electrochemical performance, and can be used in an electric lithium battery system. When the molar ratio of the two reactants of BPADE and ED2003 is 2:1 and the oxygen-lithium ratio is 16, the temperature conductivity value of the solid polymer electrolyte is 7.48 multiplied by 10^-5S·cm^-11.33X 10 at 95 DEG C^-3S·cm^-1. The solid polymer electrolyte has good flexibility, safe and stable use and good application prospect.

The reaction process of the invention is as follows:

drawings

Fig. 1 is an infrared spectrum of a polymer electrolyte thin film prepared in example 1 of the present invention;

fig. 2 is an XRD pattern of the polymer electrolyte thin film prepared in example 1 of the present invention;

FIG. 3 is a TGA profile of a polymer electrolyte film prepared in example 1 of the present invention;

FIG. 4 is a DSC of the polymer electrolyte thin film prepared in example 1 of the present invention;

FIG. 5 is a graph showing the change of the conductivity with temperature of polymer electrolyte films having different crosslinking components in examples 2 to 4 of the present invention;

FIG. 6 shows the BPADE of the present invention 3, 5, 6: ED-2003: the molar ratio of the LiTFSI is 2: 1: 4.8; 2: 1: 2.4; 2: 1: 1.6 graph of the conductivity of the electrolyte film with the temperature.

Detailed Description

For further understanding, the preferred embodiments of the present invention are described in conjunction with the examples, and it is noted that the description is intended to further illustrate the invention and not limit the scope of the invention.

Example 1

0.0851g of 2, 2-bis (4-glycidoxyphenyl) propane (BPADE) and 0.25g of polyamine ether (ED-2003) were weighed into a 5 ml glass bottle and an appropriate amount of anhydrous acetonitrile solvent was added. The mixture was then stirred on a smart constant temperature timed magnetic stirrer for 3h to complete dissolution. The transparent mixture obtained by stirring is dropped on a polytetrafluoroethylene mould by a disposable rubber dropper. The solvent was evaporated at room temperature for 24 hours (until the obtained liquid became a sol state). Finally, the mixture was placed in a vacuum drying oven and heated at 100 ℃ for 7 hours to obtain a colorless transparent film.

Example 2

0.0426g of 2, 2-bis (4-glycidoxyphenyl) propane, 0.25g of polyamine ether (ED-2003) and 0.1749g of lithium bistrifluoromethanesulfonylimide (LiTFSI) were weighed out into a 5 ml glass bottle and dissolved in acetonitrile solution, and the sample was stirred on a smart constant temperature timed magnetic stirrer for 3h to complete the dissolution. The transparent mixture obtained by stirring was dropped on a polytetrafluoroethylene mold with a disposable rubber dropper. Spreading at room temperature, volatilizing solvent for 24h to make the liquid become sol state, and finally heating and curing at 100 deg.C for 7 hr to obtain colorless transparent polymer film.

Example 3

0.0851g of 2, 2-bis (4-glycidoxyphenyl) propane, 0.25g of polyamine ether (ED-2003) and 0.1749g of lithium bistrifluoromethanesulfonylimide (LiTFSI) were weighed out into a 5 ml glass bottle and dissolved in acetonitrile solution, and the sample was stirred on a smart constant temperature timed magnetic stirrer for 3h to complete the dissolution. The transparent mixture obtained by stirring was dropped on a polytetrafluoroethylene mold with a disposable rubber dropper. Spreading at room temperature, volatilizing solvent for 24h to make the liquid become sol state, and finally heating and curing at 100 deg.C for 7 hr to obtain colorless transparent polymer film.

Example 4

0.1277g of 2, 2-bis (4-glycidoxyphenyl) propane, 0.25g of polyamine ether (ED-2003) and 0.1749g of lithium bistrifluoromethanesulfonylimide (LiTFSI) were weighed out into a 5 ml glass bottle and dissolved in acetonitrile solution, and the sample was stirred on a smart constant temperature timed magnetic stirrer for 3h to complete the dissolution. The transparent mixture obtained by stirring was dropped on a polytetrafluoroethylene mold with a disposable rubber dropper. Spreading at room temperature, volatilizing solvent for 24h to make the liquid become sol state, and finally heating and curing at 100 deg.C for 7 hr to obtain colorless transparent polymer film.

Example 5

0.0851g of 2, 2-bis (4-glycidoxyphenyl) propane, 0.25g of polyamine ether (ED-2003) and 0.0875g of lithium bistrifluoromethanesulfonylimide (LiTFSI) were weighed out into a 5 ml glass bottle and dissolved in acetonitrile solution, and the sample was placed on a smart constant temperature timed magnetic stirrer and stirred for 3h to dissolve completely. The transparent mixture obtained by stirring was dropped on a polytetrafluoroethylene mold with a disposable rubber dropper. Spreading at room temperature, volatilizing solvent for 24h to make the liquid become sol state, and finally heating and curing at 100 deg.C for 7 hr to obtain colorless transparent polymer film.

Example 6

0.0851g of 2, 2-bis (4-glycidoxyphenyl) propane, 0.25g of polyamine ether (ED-2003) and 0.0583g of lithium bistrifluoromethanesulfonylimide (LiTFSI) were weighed out into a 5 ml glass bottle and dissolved in acetonitrile solution, and the sample was stirred on a smart constant temperature timed magnetic stirrer for 3h to complete the dissolution. The transparent mixture obtained by stirring was dropped on a polytetrafluoroethylene mold with a disposable rubber dropper. Spreading at room temperature, volatilizing solvent for 24h to make the liquid become sol state, and finally heating and curing at 100 deg.C for 7 hr to obtain colorless transparent polymer film.

Claims

1. A simple method for preparing a high-performance solid polymer electrolyte is characterized by comprising the following steps: the simple method comprises the following steps: