CN102368564B - Gel-type polymer electrolyte and preparation method thereof - Google Patents

Abstract

The invention relates to a gel-type polymer electrolyte and a preparation method thereof. The gel-type polymer electrolyte membrane is prepared by using amine terminated nitrile rubber as a matrix of the solid electrolyte, dissolving the matrix, lithium salt, epoxidized polysilsesquioxane, and 1-butyl-3-methylimidazolium trifluoro methane sulfonate in an organic solvent, pouring the solvent on a teflon template, and carrying out heat treatment in a baking oven after volatilizing tetrahydrofuran. Compared with the prior art, the operation is simple; the membrane forming is easy; and the prepared membrane is smooth and uniform, has good mechanical properties, high room-temperature conductivity, and stable electrochemical window, and the prepared membrane used as solid electrolyte materials for the lithium ion battery has an application prospect.

Description

A kind of gel-type polymer electrolyte and preparation method thereof

Technical field

The present invention relates to electrolyte of a kind of technical field of lithium ion and preparation method thereof, especially relate to a kind of gel-type polymer electrolyte and preparation method thereof.

Background technology

Lithium ion battery has that energy density is large, output voltage is high, power output is large, low self-discharge, operating temperature range are wide, the advantage such as the speed that discharges and recharges is fast, and therefore, lithium ion battery is widely used in consumption electronic product, aviation war products etc.The employed electrolyte of lithium ion battery is the organic solvent electrolyte that contains lithium salts basically at present, usually bring leakage, the safety issue such as inflammable, explosive, thereby the higher gel-type polymer electrolyte of fail safe has caused researchers' attention as the substitute of traditional electrolyte.

Gel-type polymer electrolyte forms the polymer network with suitable micro-structural by preparations such as polymer, plasticizer and lithium salts by certain method, utilizes the migration that is fixed on the lithium ion in the micro-structural to realize ionic conduction.The interaction of plasticizer and lithium salts is being conducive to promote dissociating and the motion of lithium ion of lithium salts, thereby reaches higher ionic conductivity.Having of cross-linked structure is beneficial to mechanical strength and the stability that improves gel-type polymer electrolyte in the polymer network skeleton.Gel-type polymer electrolyte can obtain preferably ionic conductivity and mechanical property simultaneously, also plays a part barrier film, be applied to lithium ion battery be conducive to prepare safe and reliable, profile is changeable, the battery of function admirable.

CN101440177A discloses a kind of preparation of polymer solid electrolyte, and the method as electrolytical matrix, makes the copolymer solid electrolyte that contains lithium perchlorate with epoxy resin and acrylonitrile-butadiene rubber blend by solution casting method.This electrolyte does not contain little molecule organic solvent, and conductivity reaches 1.81 * 10 under the room temperature ^-4S/cm, but lithium perchlorate too high levels in the electrolyte are easily from the bath surface crystallization, and there is not the crosslinked network configuration of chemical bond in the polymeric matrix, dimensional stability is relatively poor, thereby makes electrolyte and electrode loose contact, and the interface resistance increasing power of lithium ion battery descends.

CN 101125935A discloses a kind of preparation method of semi-interpenetrating network gel polymer electrolyte film, the method at first prepares methacryloxy trimethoxy silane hydrolytic crosslinking product by sol-gel process, then the cross-linking reaction of initiation and PEGDMA-400 and nitrile rubber blends under ultraviolet irradiation is directly adsorbed the semi-interpenetrating network polymer parent that obtains the electrolyte activation at last.Although the 30 ℃ of lower conductivity of gel polymer electrolyte film with the method preparation reach 10 ^-3More than the S/cm, but because the electrolyte adsorbance is larger, easily oozes out from polymeric matrix, and contain residual photoinitiator molecules, reduced this electrolytical job stability, preparation flow is comparatively complicated in addition.

Summary of the invention

Purpose of the present invention be exactly provide a kind of safety and stability for technical field of lithium ion in order to overcome the defective that above-mentioned prior art exists, be easy to prepare, the gel-type polymer electrolyte of function admirable and preparation method thereof.

Purpose of the present invention can be achieved through the following technical solutions:

A kind of gel-type polymer electrolyte comprises following component and weight portion content:

Amino terminated butadiene acrylonitrile rubber 1;

Epoxidation polyhedron polysilsesquioxane 0.05～0.2;

Lithium salts 0.2～0.6;

1-butyl-3-methylimidazole fluoroform sulphonate 0.2～1.

The acrylonitrile content of described amino terminated butadiene acrylonitrile rubber is 10～26wt%, and brookfield viscosity is 180,000～500,000cP, and amino equivalent is 700～1200, and the amine value is 47～80.

Described epoxidation polyhedron polysilsesquioxane is any one in epoxidation cyclohexyl polyhedron polysilsesquioxane or the glycidol ether polyhedron polysilsesquioxane.

Described lithium salts is any one in lithium perchlorate, trifluoromethanesulfonic acid lithium or the two fluoroform sulfimide lithium.

A kind of preparation method of gel-type polymer electrolyte comprises following processing step:

With 1 weight portion amino terminated butadiene acrylonitrile rubber, 0.2～0.6 weight portion lithium salts, 0.05～0.2 weight portion epoxidation polyhedron polysilsesquioxane, 0.2～1 weight portion 1-butyl-3-methylimidazole fluoroform sulphonate magnetic agitation 30 minutes in 30 weight portion oxolanes, obtain the mixed solution of transparent and homogeneous, be cast in the polytetrafluoroethylene mould, after oxolane volatilization fully, heat treatment is 6 hours in 100 ℃ of baking ovens, namely obtains gel-type polymer electrolyte.

Compared with prior art, the present invention has the following advantages:

(1) the present invention adopts solution-cast after-baking film-forming, and the conductivity of the gel-type polymer electrolyte of gained can reach 2.00 * 10 under 30 ℃ ^-4S/cm, and the present invention is simple to operate, and film forming is easy, is easy to preparation and is processed into various shapes.

(2) gel-type polymer electrolyte of the present invention can possess the effect of electrolyte and barrier film simultaneously for lithium ion battery, and helps avoid the easy leakage of traditional organic electrolyte existence, inflammable and explosive danger.

(3) gel-type polymer electrolyte of the present invention has good viscoplasticity and dimensional stability, can good contact be arranged with electrode, helps to reduce interface resistance.

(4) gel-type polymer electrolyte of the present invention has wider electrochemical stability window, reaches 4V, meets the application requirements of lithium ion battery.

(5) gel-type polymer electrolyte of the present invention has good thermal stability, meets the Arrhenius equation in the variation of 30～70 ℃ of scope internal conductance rates.

Description of drawings

Fig. 1 is the AC impedance spectrogram that the gel-type polymer electrolyte of embodiment 1 preparation is tested under different temperatures;

Fig. 2 is the ionic conductivity of gel-type polymer electrolyte under different temperatures of embodiment 1 preparation;

Fig. 3 is the cyclic voltammogram of the gel-type polymer electrolyte of embodiment 3 preparations.

Embodiment

The present invention is described in detail below in conjunction with the drawings and specific embodiments.

The analytical method that following examples are used is as follows:

Ac resistance analysis: the Autolab PGSTA302 type electrochemical workstation of Eco Chemie company, frequency range is 1MHz～1Hz, the gel-type polymer electrolyte that makes is clipped in is assembled into airtight good test system between the stainless steel blocking electrode, carry out ac impedance measurement after half an hour reaching design temperature, by the conductivity of the AC impedance spectrogram calculated for gel type polymer dielectric that obtains:

$\mathrm{\σ}=\frac{1}{R_b}\×\frac{d}{S}$

In the formula: σ, R _b, d and S are respectively conductivity, this volume resistance, thickness and the area of gel-type polymer electrolyte.

Cyclic voltammetric is analyzed: the Autolab PGSTA302 type electrochemical workstation of Eco Chemie company, the gel-type polymer electrolyte that makes is assembled into take aluminium flake as work electrode in the glove box of argon gas atmosphere, take the lithium sheet as the Al/GPE/Li battery to electrode and reference electrode, sweep speed with 50 μ V/s under 25 ℃ is carried out cyclic voltammetry scan to battery, scanning voltage scope-0.5V～4V.

Embodiment 1～4

A kind of preparation method of gel-type polymer electrolyte, its raw material is made of following component: amino terminated butadiene acrylonitrile rubber, epoxidation cyclohexyl polyhedron polysilsesquioxane, lithium perchlorate, 1-butyl-3-methylimidazole fluoroform sulphonate, wherein, the acrylonitrile content of amino terminated butadiene acrylonitrile rubber is 18wt%, brookfield viscosity is 200,000cP, amino equivalent are 900, and the amine value is 62.

The preparation method of gel-type polymer electrolyte, comprise following processing step: according to table 1 prescription with amino terminated butadiene acrylonitrile rubber, lithium perchlorate, epoxidation cyclohexyl polyhedron polysilsesquioxane and 1-butyl-3-methylimidazole fluoroform sulphonate magnetic agitation 30 minutes in 30 parts of oxolanes, obtain the mixed solution of transparent and homogeneous, be cast in the polytetrafluoroethylene mould, after oxolane volatilization fully, heat treatment is 6 hours in 100 ℃ of baking ovens, namely obtains a kind of gel-type polymer electrolyte.The conductivity value of gained gel-type polymer electrolyte under 30 ℃ sees Table 2.

Table 1 prescription

The conductivity value of table 2 gel-type polymer electrolyte

By as seen from Table 2, when the consumption of epoxidation cyclohexyl polyhedron polysilsesquioxane is 0.05 part, when the conductivity of the gel-type polymer electrolyte that makes is 0.1 part with respect to its consumption, improved 3～4 times, shown that the epoxidation cyclohexyl polyhedron polysilsesquioxane of low consumption is conducive to improve the conductivity of gel-type polymer electrolyte.

Fig. 1 has provided the AC impedance spectrogram that the gel-type polymer electrolyte of embodiment 1 preparation is tested under different temperatures, because the stainless steel blocking electrode that adopts does not have electrochemical reaction to occur, can regard the diameter infinity as so represent the circular arc portion of electrochemical reaction in the impedance spectrogram, be similar in the drawings and show as straight line, can extrapolate resistance and ionic conductivity according to the intersection point of Nyquist curve and real axis.The conductivity of gel-type polymer electrolyte under 30 ℃ of embodiment 1 preparation reaches 2.00 * 10 ^-4S/cm.

Fig. 2 has provided the ionic conductivity of gel-type polymer electrolyte under different temperatures of embodiment 1 preparation, in 30～70 ℃ of scopes, the relation of ionic conductivity and temperature meets the Arrhenius equation, and this is consistent with the temperature variant universal law of gel-type polymer electrolyte conductivity.

$\lg \left(\mathrm{\σ}\right)=-\left(\frac{E_a}{2.303\mathrm{RT}}\right)+\lg \left(A_0\right)$

σ, E _a, R, T and A ₀Be respectively ionic conductivity, activation energy, ideal gas constant, temperature and pre-exponential factor.

Fig. 3 has provided the cyclic voltammogram of the gel-type polymer electrolyte of embodiment 3 preparations, and near two peaks the 0V represent that behavior is deviate from the reversible embedding of lithium ion on the aluminium electrode, and electrochemical stability window reaches 4V, meets the application requirements of lithium ion battery.

Embodiment 5

A kind of preparation method of gel-type polymer electrolyte, its raw material is made of following component: amino terminated butadiene acrylonitrile rubber, epoxidation cyclohexyl polyhedron polysilsesquioxane, trifluoromethanesulfonic acid lithium, 1-butyl-3-methylimidazole fluoroform sulphonate, wherein, the acrylonitrile content of amino terminated butadiene acrylonitrile rubber is 10wt%, brookfield viscosity is 180,000cP, amino equivalent are 1200, and the amine value is 47.

The preparation method of gel-type polymer electrolyte, comprise following processing step: with 1 part of amino terminated butadiene acrylonitrile rubber, 0.2 part of trifluoromethanesulfonic acid lithium, 0.2 part of epoxidation cyclohexyl polyhedron polysilsesquioxane, 0.2 part of 1-butyl-3-methylimidazole fluoroform sulphonate magnetic agitation 30 minutes in 30 parts of oxolanes, obtain the mixed solution of transparent and homogeneous, be cast in the polytetrafluoroethylene mould, after oxolane volatilization fully, heat treatment is 6 hours in 100 ℃ of baking ovens, namely obtains gel-type polymer electrolyte.

Embodiment 6

A kind of preparation method of gel-type polymer electrolyte, its raw material is made of following component: amino terminated butadiene acrylonitrile rubber, epoxidation cyclohexyl polyhedron polysilsesquioxane, two fluoroform sulfimide lithium, 1-butyl-3-methylimidazole fluoroform sulphonate, wherein, the acrylonitrile content of amino terminated butadiene acrylonitrile rubber is 26wt%, brookfield viscosity is 500,000cP, amino equivalent are 700, and the amine value is 80.

The preparation method of gel-type polymer electrolyte, comprise following processing step: with the two fluoroform sulfimide lithiums of 1 part of amino terminated butadiene acrylonitrile rubber, 0.6 part, 0.05 part of glycidol ether polyhedron polysilsesquioxane, 1 part of 1-butyl-3-methylimidazole fluoroform sulphonate magnetic agitation 30 minutes in 30 parts of oxolanes, obtain the mixed solution of transparent and homogeneous, be cast in the polytetrafluoroethylene mould, after oxolane volatilization fully, heat treatment is 6 hours in 100 ℃ of baking ovens, namely obtains gel-type polymer electrolyte.

Claims (2)

1. a gel-type polymer electrolyte is characterized in that, this electrolyte is prepared by the component of following weight portion content:

Amino terminated butadiene acrylonitrile rubber 1;

Epoxidation polyhedron polysilsesquioxane 0.05～0.2;

Lithium salts 0.2～0.6;

1-butyl-3-methylimidazole fluoroform sulphonate 0.2～1,

The acrylonitrile content of described amino terminated butadiene acrylonitrile rubber is 10～26wt%, and brookfield viscosity is 180,000～500,000cP, and amino equivalent is 700～1200, and the amine value is 47～80;

Described epoxidation polyhedron polysilsesquioxane is any one in epoxidation cyclohexyl polyhedron polysilsesquioxane or the glycidol ether polyhedron polysilsesquioxane;

Described lithium salts is any one in lithium perchlorate, trifluoromethanesulfonic acid lithium or the two fluoroform sulfimide lithium.

2. the preparation method of a gel-type polymer electrolyte is characterized in that, this preparation method comprises following processing step:

With 1 weight portion amino terminated butadiene acrylonitrile rubber, 0.2～0.6 weight portion lithium salts, 0.05～0.2 weight portion epoxidation polyhedron polysilsesquioxane, 0.2～1 weight portion 1-butyl-3-methylimidazole fluoroform sulphonate magnetic agitation 30 minutes in 30 weight portion oxolanes, obtain the mixed solution of transparent and homogeneous, be cast in the polytetrafluoroethylene mould, after oxolane volatilization fully, heat treatment is 6 hours in 100 ℃ of baking ovens, namely obtains gel-type polymer electrolyte;

Wherein, the acrylonitrile content of described amino terminated butadiene acrylonitrile rubber is 10～26wt%, and brookfield viscosity is 180,000～500,000cP, and amino equivalent is 700～1200, and the amine value is 47～80;

Described epoxidation polyhedron polysilsesquioxane is any one in epoxidation cyclohexyl polyhedron polysilsesquioxane or the glycidol ether polyhedron polysilsesquioxane;

Described lithium salts is any one in lithium perchlorate, trifluoromethanesulfonic acid lithium or the two fluoroform sulfimide lithium.

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