CN105826596A

CN105826596A - Preparation method for ionic liquid and secondary battery

Info

Publication number: CN105826596A
Application number: CN201510575017.4A
Authority: CN
Inventors: 郑卓群; 申大卫; 邱建; 聂云华; 赵晓珍; 李丹祎
Original assignee: Microvast Power Systems Huzhou Co Ltd
Current assignee: Microvast Power Systems Huzhou Co Ltd
Priority date: 2015-01-22
Filing date: 2015-09-11
Publication date: 2016-08-03
Anticipated expiration: 2035-09-11
Also published as: CN105826596B

Abstract

The invention relates to a preparation method for ionic liquid, especially to a one-step method for synthesis of a quaternary ammonium or quaternary phosphonium compound. According to the method, a nitrogen compound or phosphorus-containing compound, a proton compound and carbonic ester are added into a reactor together for a one-step reaction so as to synthesize corresponding quaternary ammonium or quaternary phosphonium ionic liquid, wherein the reaction is a one-pot reaction involving three reactants. The invention also provides a lithium ion secondary battery of the ionic liquid prepared by using the preparation method. The preparation method for the ionic liquid can broaden the selection scope of preparation raw materials for the ionic liquid, so the varieties of synthesized ionic liquid are enriched; and the preparation method utilizes nontoxic and harmless raw materials, has mild reaction conditions, low requirements on production equipment and low production cost, and meets demands of green industry and large-scale industrial production.

Description

The preparation method of ionic liquid and secondary cell

Technical field

The present invention relates to the preparation method of a kind of ionic liquid, particularly to a kind of one-step synthesis method quaternary ammonium or the method for quaternary compound.

Background technology

Ionic liquid (ionicliquid) is the liquid being composed entirely of ions, it is liquid under room temperature or low temperature (-97 DEG C～100 DEG C), therefore also known as room temperature/low temperature molten salt (room/lowtemperaturemoltensalt), or liquid organic salt (liquidorganicsalt) is claimed.The kind of ionic liquid is a lot, according to the difference of organic cation, ionic liquid can be divided into quaternary ammonium salt, quaternary salt class, nitrogen heterocyclic ring salt etc., and the ring-like ionic liquid of nitrogen-containing hetero includes imidazole salt, pyridine salt, piperidines salt, pyrrolidine salt etc..The anion species of composition ionic liquid is various, and inorganic anion includes F^-、Cl^-、Br^-、I^-、NO₃ ^-、CO₃ ^2-、PF₆ ^-、BF₄ ^-、C₂O₄ ^2-、SO₄ ^2-、PO₄ ^3-、Al₂Cl₇ ^-Deng, organic anion includes CH₃COO^-、CF₃SO₃ ^-、C₄H₉SO₃ ^-、CF₃COO^-、N(FSO₂)₂ ^-、N(CF₃SO₂)₂ ^-、N(C₂F₅SO₂)₂ ^-、N(C₄F₉SO₂)₂ ^-、N[(CF₃SO₂)(C₄F₉SO₂)]^-、C(CF₃SO₂)₃ ^-Deng.Theoretically, the kind of ionic liquid can have 10¹⁸More than Zhong.The cation of several frequently seen imine ionic liquid and the structure of anion are as follows:

20 century 70s, American scientist JohnS.Wilks is applied to battery system ionic liquid first.Since the nineties in 20th century, people are to ionic liquid in the application start further investigation of lithium rechargeable battery, and ionic liquid is increasingly subject to accreditation and the attention of expert as electrolyte solvent for the feasibility of lithium rechargeable battery and superiority.Compare now widely used carbonate based organic solvent, ionic liquid is used as the electrolyte solvent of lithium rechargeable battery and has the advantage that (1) liquid journey temperature range width, such as it is commonly used to the electrolyte solvent dimethyl carbonate (DMC) of lithium rechargeable battery, its liquid state range is narrow, it it is 2 DEG C～90 DEG C, the liquid ceiling temperature of major part ionic liquid can reach about 300 DEG C (decomposition temperature), the even liquid state range of some ionic liquid wide to-70 DEG C～400 DEG C, expand the use temperature range (such as extending) of lithium rechargeable battery to high temperature；(2) ionic liquid is ionic substance, dissolves ionic compound ability by force, and concentration controllable, several frequently seen lithium salts such as LiPF₆、LiBF₄、LiCF₃SO₃、LiN(SO₂CF₃)₂Deng solubilized equal in corresponding ionic liquid, and higher concentration can be reached, can meet when lithium rechargeable battery is used as electrokinetic cell the requirement of lithium concentration in electrolyte；(3) electric conductivity is good, and under conditions of lithium salts, the electrical conductivity of itself can also reach 1～10mS cm^-1Rank；(4) good stability, ionic liquid has preferable heat stability and chemical stability, the decomposition temperature of most of ionic liquids more than 400 DEG C, chemical stability be embodied in ionic liquid under general condition with conventional electrode material of secondary lithium ion battery such as LiFePO₄、LiCoO₂、Li₄Ti₅O₁₂, the not chemically reactive such as graphite；(5) though ionic liquid at a temperature of more than 100 DEG C also without notable vapour pressure, when battery runs in high temperature environments, hyperbar will not be produced and make battery deform upon in battery, such as, be applied to aluminum plastic film soft-package battery, not easily cause " bulge " phenomenon；(6) without flash-point, burning-point is high, and some ionic liquid i.e. uses naked light also to be difficult to light, and currently used carbonate solvent is inflammable, explosive, being applied to lithium rechargeable battery and there is potential safety hazard, ionic liquid is expected to solve the safety issue of lithium rechargeable battery.

At present, being applied to the ionic liquid of lithium rechargeable battery as electrolyte solvent mainly has anion to be tetrafluoroborate (BF₄ ^-), hexafluoro-phosphate radical (PF₆ ^-), trifluoromethane sulfonic acid root (CF₃SO₃ ^-), two (trimethyl fluoride sulfonyl) imines (N (CF₃SO₂)₂ ^-) etc. quaternary ammonium salt, piperidines salt, pyrrolidine salt, imidazole salt, pyridine salt ionic liquid.The combination of different zwitterions is very big on physics and the chemical property impact of ionic liquid electrolyte, and directly affects the performance of lithium rechargeable battery.In recent years, numerous researchs show that anion is that the ionic liquid of imines ion often has lower fusing point, the fused salt that can form fusing point less than zero degree is combined with multiple cation, widen the range of choice of cation, made to have the quaternary ammonium cation of more high electrochemical stability, piperidines cation, pyrrolidine cation are applied to lithium ion secondary battery system.The fusing point of such as N-methyl-N-butyl piperidine two (trimethyl fluoride sulfonyl) inferior amine salt [PP13-TFSI] is-18 DEG C, is used for Li/LiCoO₂Battery system performance excellence, the specific capacity of positive pole can play to 150mAh g^-1, coulombic efficiency can reach 100%, circulates tens of week without substantially decay (Jin Qiang etc. perhaps, " chemistry journal " volume 63 18 phase page 1733)；University Of Suzhou Zheng Hong river research group finds N, N, N-trimethyl-N-hexyl two (trimethyl fluoride sulfonyl) imines quaternary ammonium salt is applied to the lithium rechargeable battery that hard carbon is negative pole, even if battery also discharge and recharge is normal under 80 DEG C of high temperature, ionic liquid cation hard carbon cathode do not occur embed and deintercalation behavior, they think this ionic liquid be combined with hard carbon have application prospect (RSCAdv., 2012,2,4,904 4912).

The traditional processing technology of ionic liquid, as a example by quaternary ammonium salt, is the method using tertiary amine and alkyl halide to be alkylated reaction, and its reaction is shown below:

R₁R₂R₃N+R₄X→[R₁R₂R₃R₄N]⁺X^-(1)

Such as, tributyl methyl phosphonium iodide ammonium can be prepared by tributyl tertiary amine and iodomethane reaction:

(C₄H₉)₃N+CH₃I→[(C₄H₉)₃NCH₃]⁺I^-(2)

Prepare at least to replace on nitrogen element and have the quaternary ammonium salt of a methyl, it is also possible to make alkylating reagent by dimethyl sulfate, be shown below:

R₁R₂R₃N+(CH₃)₂SO₄→[R₁R₂R₃NCH₃]⁺CH₃SO₄ ^-(3)

Tertiary amine and dimethyl sulfate are easier to reaction, and yield is high, but use the shortcoming of dimethyl sulfate to be its severe toxicity, have carcinogenesis.The maximum weak point of above-mentioned process route is to prepare certain several quaternary ammonium salt, such as, according to the method for halogenated alkane quaterisation, can only prepare anion is Cl^-、Br^-、I^-Quaternary ammonium salt；According to the method for dimethyl sulfate quaterisation, can only prepare anion is CH₃SO₄ ^-Quaternary ammonium salt.When being the quaternary ammonium salt of other ion if desired for preparation anion, can only be realized by ion-exchange reactions, as realized by the ion-exchange reactions shown in formula (4) and formula (5):

[R₁R₂R₃R₄N]⁺X^-+H⁺A^-→[R₁R₂R₃R₄N]⁺A^-+H⁺X^-(4)

[R₁R₂R₃R₄N]⁺X^-+M⁺A^-→[R₁R₂R₃R₄N]⁺A^-+M⁺X^-(5)

Such as, preparation anion is SO₄ ^2-Quaternary ammonium salt [R₁R₂R₃R₄P]₂ ²⁺SO₄ ^2-The most first via formula (1) synthesizing chlorinated quaternary ammonium salt, make quaternary ammonium chloride and sulfuric acid reaction via formula (4) the most again, utilize the volatile feature of hydrochloric acid to remove hydrochloric acid, make reaction (4) balance move right, thus reach ion exchange to greatest extent.And for example preparing anion is BF₄ ^-Quaternary ammonium salt [R₁R₂R₃R₄P]⁺BF₄ ^-, in like manner first synthesize corresponding quaternary ammonium halides salt via formula (1), then make quaternary ammonium halides salt and metal inorganic salt such as NaBF via formula (5)₄Reacting in organic solvent is such as acetone, the feature utilizing metal halide dissolubility in organic solvent little makes halogen ion separate out to realize the purpose of ion exchange with precipitation form.Obviously, formula (4) and formula (5) are all balancing responses, all there is the halfway phenomenon of reaction, inevitably residual halogens ion in final products.Even with silver salt such as AgBF₄, make reaction (5) to carry out in aqueous, and can react complete, but high cost.

On the one hand, due to halide anion such as Cl^-、Br^-、I^-Equistability is poor, the most oxidized and discharge toxic property, corrosive halogen simple substance, and its range of application is restricted；On the other hand, along with in-depth and the extension of research, it has been found that (F when anion is a certain in following ion^-、NO₃ ^-、CO₃ ^2-、PF₆ ^-、BF₄ ^-、C₂O₄ ^2-、SO₄ ^2-、PO₄ ^3-、Al₂Cl₇ ^-、CH₃COO^-、CF₃SO₃ ^-、C₄H₉SO₃ ^-、CF₃COO^-、N(CF₃SO₂)₂ ^-、N(FSO₂)₂ ^-、N(C₂F₅SO₂)₂ ^-、N(C₄F₉SO₂)₂ ^-、N[(CF₃SO₂)(C₄F₉SO₂)]^-、C(CF₃SO₂)₃ ^-Etc.), quaternary ammonium salt generally has some characteristic not available for quaternary ammonium halides salt, and such as fusing point is lower, conductivity is higher, viscosity is lower, hydrophobicity is strong etc., thus has widely purposes.To this end, the new preparation process developing these special quaternary ammonium salts is particularly important.

United States Patent (USP) US4892944 describes dimethyl carbonate as a kind of method preparing quaternary ammonium/salt of alkylating reagent.The method is undertaken in two steps, first step tertiary amine/phosphine generates quaternary ammonium/methylcarbonate with dimethyl carbonate, second step quaternary ammonium/methylcarbonate and acid reaction discharge methanol and carbon dioxide prepared quaternary ammonium/salt, the anion species of quaternary ammonium/salt is by the acid decision used, and reaction equation is as follows:

R₁R₂R₃N(P)+Me₂CO₃→[R₁R₂R₃N(P)Me]⁺MeCO₃ ^-(6)

[R₁R₂R₃N(P)Me]⁺MeCO₃ ^-+H⁺A^-→[R₁R₂R₃N(P)Me]⁺A^-+MeOH+CO₂(7)

The feature of the method is, the anion of the quaternary ammonium/salt prepared is the anion of various acid, is not limited by quaternary ammonium/change reagent, and the anion range of choice is big.But, still being limited to reactant must be that tertiary amine or tertiary phosphine, only tertiary amine or tertiary phosphine could be generated corresponding quaternary ammonium/salt, ammonia (NH by dimethyl carbonate alkylation₃), primary amine, secondary amine or hydrogen phosphide (PH₃), primary phosphine and secondary phosphine can not be can not get quaternary ammonium/cation by dimethyl carbonate alkylation.

Chinese patent (CN200510061094.4, applying date 2005.10.10；CN200710008626.7, applying date 2007.2.14) all disclose a kind of carbonic diester (fat) and amine (ammonia) salt under the conditions of suitable temperature, pressure etc. (50 DEG C～300 DEG C, 0.5MPa～50Mpa, 4～12h) method that quaternary ammonium salt is prepared in reaction, being all with carbonic ester as alkylating reagent, in course of reaction, methyl replaces the hydrogen in amine salt thus prepares quaternary ammonium salt.But two kinds of technical schemes make a big difference again, main distinction technical characteristic is exactly the use of catalyst.The technical scheme of patent CN200510061094.4 needs use selected from metallic compound, nonmetallic compound, its mixture or the catalyst of ionic liquid, the most also the problem that product separates is certainly existed with catalyst, and it is difficult to ensure that the high-purity of product；And the technical scheme disclosed in patent CN200710008626.7 does not use catalyst, and it being not related to follow-up loaded down with trivial details separation process, operating process is relatively easy, and product purity is greatly improved, and more can be suitably used for some and product purity is required higher application.But, these two kinds of synthetic methods all emphasize it is from amine (ammonia) salt, the product NH after i.e. neutralizing with amine (ammonia) and acid₄ ⁺L^-、RNH₃ ⁺L^-、R₁R₂NH₂ ⁺L^-、R₁R₂R₃NH⁺L^-For reactant, synthesize corresponding quaternary ammonium salt.

Summary of the invention

First purpose of the present invention is to provide a kind of method of one-step method (i.e. " one kettle way ") synthesis ionic liquid, the method can widen the range of choice preparing ionic liquid needed raw material, and then widened the ionic liquid kind of synthesis, in this preparation method, raw material is nontoxic, reaction condition is gentle, to producing, equipment requirements is the highest, and production cost is low, it is adaptable to green chemical industry and big industrial production demand.The concrete technical scheme used by realizing first purpose of the present invention is: the preparation method of ionic liquid, nitrogen-containing compound or phosphorus-containing compound, proton compound and carbonic ester synthesize ionic liquid by single step reaction；Described nitrogen-containing compound is selected from ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂And tertiary amine (R NH)₁R₂R₃N) at least one；Described phosphorus-containing compound is selected from hydrogen phosphide (PH₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂And tertiary phosphine (R PH)₁R₂R₃P) at least one；Wherein, R₁、R₂、R₃It is independently selected from hydrogen, alkyl, thiazolinyl, alkynyl, phenyl or aryl；Or R₁、R₂、R₃It is independently selected from the organic group of at least one element in boracic, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, bromine and iodine；Described R₁、R₂、R₃For independent substituted radical；Or described R₁、R₂、R₃Cyclization is combined for adjacent group.As a example by nitrogen-containing compound, can be sp³The ammonia of-hydridization or amine, it is also possible to be sp²The group with imine moiety of-hydridization.Wherein, R₁、R₂、R₃Structure can be identical, it is also possible to different.As further preferably, described organic group is alkyl, thiazolinyl, alkynyl, phenyl or aryl.

Ionic liquid according to the inventive method synthesis is particularly well-suited to require compound purity high electro-chemical systems, such as lithium rechargeable battery, electric chemical super capacitor etc., is of course also apply to the fields such as green chemical industry, biology, catalysis.According to the method, advantages of nontoxic raw materials without, material choice scope is wide, and reaction condition is gentle, and to producing, equipment requirements is the highest, and the present invention can use the applicable liquid reactive reaction vessel of all routines in principle, charging, batch mixing, distill, filtration etc. operates the simplest.

The invention provides a kind of single step reaction and prepare season and the method for quaternary compound class ionic liquid, different from conventional method, the inventive method is " one kettle way ", i.e. three kinds reactants (amine or phosphine, carbonic ester and proton compound) add to reactor enforcement reaction together, and achieve with ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂NH), tertiary amine (R₁R₂R₃Or hydrogen phosphide (PH N)₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂PH), tertiary phosphine (R₁R₂R₃P) it is that initial reactant passes through the prepared corresponding quaternary ammonium of single step reaction (or primary first-order equation) or the highway route design of quaternary compound.Comparing the two-step reaction method (United States Patent (USP) US4892944) as starting material with tertiary phosphine or tertiary amine, " one kettle way " in the present invention, can be with ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂NH), tertiary amine (R₁R₂R₃Or hydrogen phosphide (PH N)₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂PH), tertiary phosphine (R₁R₂R₃P) being initial reactant, it is clear that the selection degree of freedom of reaction mass is bigger, the ionic liquid structure change prepared is various, and kind is more.Such as, prepare tetramethyl tetrafluoroborate, according to the inventive method, hydrogen phosphide (PH₃), methylphosphine, dimethylphosphine, three methylphosphines can be employed as initial reactant, and according to United States Patent (USP) US4892944, three methylphosphines can only be selected as reactant in fact.Comparing Chinese patent (CN200510061094.4 and CN200710008626.7), be the method that initial reactant prepares quaternary ammonium salt with amine (ammonia) salt, the inventive method is with amine as initial reactant, it is clear that simplify reactions steps.With amine salt as reactant, it is necessary to first passing through amine and prepare amine salt with sour reaction, then amine salt and carbonate reaction can prepare quaternary ammonium compound.And " one kettle way " reaction of design in the inventive method, three kinds of reactants (amine, carbonic ester and proton compound) add together to reactor, are the reactions of three kinds of reactants, are not related to amine salt, regardless of first step reaction, second step reaction.

Nitrogen-containing compound or phosphorus-containing compound, proton compound and carbonic ester are added in reactor by single step reaction of the present invention simultaneously；Or first carbonic ester, nitrogen-containing compound or phosphorus-containing compound are added in reactor, then proton compound is joined in reactor；Or first proton compound, nitrogen-containing compound or phosphorus-containing compound are added in reactor, then carbonic ester is joined in reactor；Or first nitrogen-containing compound or phosphorus-containing compound are added in reactor, then carbonic ester, proton compound are joined in reactor.

One embodiment of the present invention, three kinds of reactants (A represents nitrogen-containing compound or phosphorus-containing compound, B represents carbonic ester, C represents proton compound) can add to reactor participation reaction by presetting amount simultaneously；First A Yu B can also be added in reactor, then be passed through C by certain speed；First A Yu C can also be added in reactor, then be passed through B by certain speed；First A can also be added in reactor, then be passed through B and C by certain speed.As described embodiments, embodiment 14, embodiment 15, embodiment 16, embodiment 19, embodiment 20, embodiment 21, embodiment 23, embodiment 26, it is to be initially charged reactant A and reactant B, then reactant C is added, reaction is from amine, it is clearly distinguishable from Chinese patent (CN200510061094.4 with CN200710008626.7) disclosed from the reaction scheme of amine salt, embodiment 10 and embodiment 13, reaction is from primary amine, hence it is evident that be different from United States Patent (USP) US4892944 disclosed from tertiary amine or the reaction scheme of three grades of phosphines.Particularly pointing out, the difference between the reaction scheme disclosed in embodiment 17, embodiment 18, embodiment 22, embodiment 24, embodiment 25 and existing technology, especially it is clear that be specifically shown in Table 1.

Table 1 various embodiments of the present invention reaction actual conditions

In table, HTFSI refers to double (trimethyl fluoride sulfonyl) imines, and HFSI refers to double (fluorine sulphonyl) imines.

As preferably, described nitrogen-containing compound is selected from following structure at least one:

Wherein, R₁、R₂、R₃、R₄、R₅、R₆It is independently selected from hydrogen, alkyl, thiazolinyl, alkynyl, phenyl or aryl；Or R₁、R₂、R₃、R₄、R₅、R₆It is independently selected from the organic group of at least one element in boracic, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, bromine and iodine；Described R₁、R₂、R₃、R₄、R₅、R₆For independent substituted radical；Or described R₁、R₂、R₃、R₄、R₅、R₆Cyclization is combined for adjacent group.Wherein, R₁、R₂、R₃、R₄、R₅、R₆Structure can be identical, it is also possible to different.As further preferably, described organic group is alkyl, thiazolinyl, alkynyl, phenyl or aryl.

As further preferably, described phosphorus-containing compound is selected from methylphosphine, dimethylphosphine, three methylphosphines, ethyl phosphine, diethyl phosphine, triethyl phosphine, tripropyl phosphine, di-t-butyl phosphine, tri-butyl phosphine, tributylphosphine, three n-pentyl phosphines, cyclohexyl phosphine, dicyclohexylphosphontetrafluoroborate, tricyclohexyl phosphine, three hexyl phosphines, tri octyl phosphine, Phenylphosphine, diphenylphosphine, triphenylphosphine, dimethylphenylphosphine, diethyl Phenylphosphine, diphenyl butylphosphine, tribenzyl phosphine, tris hydroxymethyl phosphine, 2-ethyl chloride diethyl phosphine and three (pentafluoroethyl group) phosphine at least one.

As further preferably, described proton compound is selected from inorganic oxacid, inorganic oxygen-free acid, organic acid and non-acids proton compound at least one.Proton compound of the present invention refers to the most at least to provide a proton and nitrogen-containing compound to include ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂NH), tertiary amine (R₁R₂R₃N) material that the N element on combines, or include hydrogen phosphide (PH with phosphorus-containing compound₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂PH), tertiary phosphine (R₁R₂R₃P) material that the P element on combines,

As further preferred, described inorganic oxygen-containing is selected from meta-aluminic acid (HAlO₂), tetrahydroxy close aluminum (III) acid (HAl (OH)₄), arsenic acid (H₃AsO₄), metaarsenous acid (HAsO₂), arsenious acid (H₃AsO₃), pyroarsenic acid (H₄As₂O₇), boric acid (H₃BO₃), metaboric acid ((HBO₂)_n), tetraboric acid (H₂B₄O₇), perboric acid (HBO₃), 12 tungsten boric acid (H₅BW₁₂O₄₀), bromic acid (HBrO₃), bromous acid (HBrO₂), Hydrogen oxybromide (HOBr) (HBrO), hyperbromic acid (HBrO₄), orthocarbonic acid (H₄CO₄), cross two carbonic acid (H₂C₂O₆), percarbonic acid (H₂CO₄Or H₂CO₃·H₂O₂), chloric acid (HClO₃), perchloric acid (HClO₄), chlorous acid (HClO₂), hypochlorous acid (HClO), fulminic acid (HONC), cyanic acid (HOCN), Carbimide. (HNCO), iodic acid (HIO₃), Hypoiodous acid (HIO) (HIO or IOH), metaperiodic acid (HIO₄), periodic acid (H₅IO₆), burnt periodic acid (H₄I₂O₉), nitric acid (HNO₃), nitrous acid (HNO₂), phosphoric acid (H₃PO₄), former phosphoric acid (H₅PO₅), Metaphosphoric acid (HPO₃) n, phosphorous acid (H₃PO₃), pyrophosphorous acid (H₄P₂O₅), metaphosphorous acid (HPO₂), hypophosphorous acid (H₃PO₂), hypophosphoric acid (H₄P₂O₆), pyrophosphoric acid (H₄P₂O₇), sulphuric acid (H₂SO₄), sulfurous acid (H₂SO₃), thiosulfuric acid (H₂S₂O₃), pyrosulfuric acid (H₂S₂O₇), sulphoxylic acid (H₂SO₂), polythionic acid (H₂S_xO₆, x=2～6), ortho-sulfuric acid (H₆SO₆), hydrosulfurous acid (H₂S₂O₄), permonosulphuric acid (H₂SO₅), peroxy-disulfuric acid (H₂S₂O₈), chlorosulfonic acid (HSO₃Cl), fluosulfonic acid (HSO₃F), metasilicic acid (H₂SiO₃Or SiO₂·H₂O), orthosilicic acid (H₄SiO₄), two metasilicic acid (H₂Si₂O₅Or 2SiO₂·H₂O), three silicic acid (H₄Si₃O₈) and disilicic acid (H₆Si₂O₇Or 2SiO₂·3H₂O) at least one.

As further preferred, described inorganic oxygen-free acid is selected from carborane acid (H [CHB₁₁Cl₁₁]), hydrosulphuric acid (H₂S), Perthiocarbonate (H₂CS₄), thiocarbonic acid (H₂CS₃), hydrocyanic acid (HCN), selenium cyanic acid (HSeCN), Hydrogen thiocyanate (HSCN), fluoboric acid (HBF₄), hexafluosilicic acid (H₂SiF₆), hexafluorophosphoric acid (HPF₆), Fluohydric acid. (HF), hydrochloric acid (HCl), in hydrobromic acid (HBr) and hydroiodic acid (HI) at least one.

As further preferred, described organic acid is selected from oxalic acid, formic acid, acetic acid, propanoic acid, succinic acid, trifluoracetic acid, trifluoromethanesulfonic acid, methanesulfonic acid, mandelic acid, methylsulfuric acid, ethyl sulfuric acid, oleic acid, stearic acid, acrylic acid, maleic acid, citric acid, double (catechol) boric acid, double oxalic acid boric acid, dimalonic acid boric acid, three (pentafluoroethyl group) three fluorophosphoric acid, triethyl group three fluorophosphoric acid, four cyano boric acid, tartaric acid, malic acid, citric acid, ascorbic acid, benzoic acid, benzenesulfonic acid, p-methyl benzenesulfonic acid, salicylic acid and caffeic acid at least one.

The method according to the invention, above-mentioned proton compound also includes that scope far surpasses the acid compounds of common meaning, they are defined as non-acids proton compound by the present invention, this compounds active proton hydrogen, and owing to neighboring group has the strongest electron-withdrawing and makes hydrogen atom have greater activity, the most above-mentioned non-acids proton compound can discharge active proton.As further preferred, described non-acids proton compound is group with imine moiety；Described group with imine moiety has such as formula 1, formula 2 or the structure shown in formula 3:

Formula 1:HN (C_mF_2m+1SO₂)(C_nF_2n+1SO₂)；

Formula 2:HN (C_nF_2n+1SO₂)₂；

Formula 3:HN (C_xF_2xSO₂)₂；

Wherein m is the integer of 0～5, and n is the integer of 0～5, and X is the integer of 1～10.

As further preferred, described group with imine moiety is selected from following structural formula at least one:

As further preferred, described non-acids proton compound selected from three (trimethyl fluoride sulfonyl) methane, phenol, p-methyl phenol, betanaphthol, 2, in 4-chlorophenesic acid and mutual-amino phenol at least one.

As further preferred, described carbonic ester is selected from dimethyl carbonate, Ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, Allyl carbonate, phenyl-carbonic acid methyl ester, diphenyl carbonate and dimethyl benzyl at least one.

In the present invention, the kind of proton compound is influential for the yield of final reacting product.According to one embodiment of the present invention, acid strong acid is conducive to provide high product yield, such as in halogen acids, hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid (HI) are all strong acid, and the yield of product is the highest.It addition, same type of acid often has close product yield, inorganic complex acid such as fluoboric acid (HBF₄), hexafluorophosphoric acid (HPF₆) there is close product yield.Certainly, the influence factor of product yield is polynary, also has relation with the structure of nitrogen-containing compound or the structure of phosphorus-containing compound and carbonic ester.

Quaternizing agent in the inventive method and quaternizing agents carbonic ester can be expressed as RO-CO-OR ' (may also be referred to as alkylating reagent), wherein, R, R ' it is independently selected from containing hydrocarbon alkyl, thiazolinyl, alkynyl, phenyl or aryl；Or R, R ' it is independently selected from the organic group of at least one element in boracic, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, bromine and iodine.R, R ' structure can be identical, it is also possible to different；R, R ' can be independent substituted radical, it is also possible to it is adjacent group combines cyclization.

Consider substituent R, R ' to electronics/factor such as sucting electronic effect, space steric effect to the thermodynamics of alkylated reaction, kinetic effect, preferably be selected from dimethyl carbonate, Ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, Allyl carbonate, phenyl-carbonic acid methyl ester, diphenyl carbonate and dimethyl benzyl at least one；Particularly preferably in dimethyl carbonate, Ethyl methyl carbonate and diethyl carbonate at least one.Particularly point out, when carbonic ester is circulus, utilize the method in the present invention can obtain polyfunctional compound.Such as add ethylene carbonate or Allyl carbonate makees alkylating reagent, ethoxy (-CH can be introduced in end product respectively₂CH₂And 2-hydroxypropyl (-CH OH)₂CHOHCH₃).Due to the introducing of hydroxyl, on the one hand expand the application (such as strengthening hydrophilic or water solublity, can apply to water-related field) of quaternary ammonium salt or quaternary salt；On the other hand, provide condition for " grafting " other functional group, on the basis of hydroxyl can sense dough further, such as halogenation, be etherified, esterification etc., it is also possible to by being oxidized to carboxylic acid.

As preferably, it is 100～200 DEG C that the temperature of described single step reaction controls.As further preferably, it is 120～180 DEG C that the temperature of described single step reaction controls.As further preferred, as further preferred, it is 140～160 DEG C that the temperature of described single step reaction controls.

As preferably, it is 0.1～3.0Mpa that the absolute pressure of described single step reaction controls.As further preferably, it is 0.8～2.0Mpa that the absolute pressure of described single step reaction controls.As further preferred, it is 1.0～1.5Mpa that the absolute pressure of described single step reaction controls.In practical operation, if exothermic heat of reaction is obvious, preferably slows down the addition speed of one of which reactant, or lower the temperature；If reaction pressure rises too fast, it is also possible to preferably by the method slowing down one of which reactant rate of feeding.

As preferably, it is 0.1～20 hour that the response time of described single step reaction controls.As further preferably, it is 4～15 hours that the response time of described single step reaction controls.As further preferred, it is 9～12 hours that the response time of described single step reaction controls.

In the synthetic method of the present invention, reaction can be carried out in certain solvent, it is also possible to carries out under solvent free conditions.Use solvent, beneficially reactant mix homogeneously, in general, be conducive to reaction to carry out under lower reaction temperature or the yield of product is higher.But, introducing solvent, also bring along many troubles, cost increases, and there is potential safety hazard, and also to recycle.The inventive method is not construed as limiting the need of solvent, and the solvent used in reaction is not made specific requirement.Generally, if selection solvent, then during solvent can be selected from alcohols (preferably methanol, ethanol), ethers, ketone (preferably acetone), carbonates (preferably dimethyl carbonate), nitrile, alkane, halogenated hydrocarbons and aromatic hydrocarbon at least one.Further, solvent can also be selected from least one in methanol, ethanol, acetone and dimethyl carbonate.

According to the synthetic method of the present invention, nitrogen-containing compound such as ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂NH), tertiary amine (R₁R₂R₃Or phosphorus-containing compound such as hydrogen phosphide (PH N)₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂PH), tertiary phosphine (R₁R₂R₃P) with the mol ratio of proton compound depending on the proton number that proton compound can provide.As a example by phosphorus-containing compound, if a part proton compound may only provide a proton, then, hydrogen phosphide (PH₃) or organic phosphoric compound (include primary phosphine R₁PH₂, secondary phosphine R₁R₂PH, tertiary phosphine R₁R₂R₃P) it is preferably 1:1 with proton compound mol ratio.Such as, hydrogen phosphide (PH₃) add in reactor with mol ratio 1:1 with Fluohydric acid. (HF).If a part proton compound can provide two or the proton of more than two, then hydrogen phosphide (PH₃) or organic phosphoric compound (include primary phosphine R₁PH₂, secondary phosphine R₁R₂PH, tertiary phosphine R₁R₂R₃P) mol ratio with proton compound can be 1:1,2:1 or 3:1, and such as, a part phosphoric acid at most can provide 3 protons, triethyl phosphine and phosphoric acid can distinguish in the reactor of 1:1,2:1 or 3:1 addition in molar ratio.Mol ratio can have deviation, a certain reactant can excess, can consider to select which kind of material somewhat excess more favorably (Financial cost low and environmental friendliness) according to the combined factors such as Material Cost height, waste recovery difficulty or ease.In like manner, nitrogen-containing compound such as ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂NH), tertiary amine (R₁R₂R₃Or phosphorus-containing compound such as hydrogen phosphide (PH N)₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂PH), tertiary phosphine (R₁R₂R₃P) with the mol ratio of carbonic ester depending on the numbers of hydrogen atoms in compound.Such as, PH₃1:4, RPH is can be set as with the mol ratio of carbonic ester₂1:3, R is can be set as with the mol ratio of carbonic ester₁R₂PH can be set as 1:2, R with the mol ratio of carbonic ester₁R₂R₃P can be set as 1:1 with the mol ratio of carbonic ester.In order to ensure high product yield, the amount of carbonic ester can excess.Certainly, in order to ensure that reaction carries out completely, it is also possible to consider that boiling point reactant relatively low, lower-cost is the most excessive, after reaction completely can by washing, distill or the modes such as distillation, recrystallization that reduce pressure remove.

After the present invention reacts completely, unreacted reactant and solvent can be removed by modes such as distillation, decompression distillation, recrystallization, washings.Before reaction starts, preferentially can take the air in reaction vessel away to avoid because reaction is adversely affected by air with the air in inert atmosphere displacement reaction container or with vacuum pump.From reaction mechanism, the one of which by-product of reaction is CO₂.Along with constantly carrying out of reaction, CO₂Amount be continuously increased, in causing reaction vessel, pressure constantly rises.Consider safety in production and reduce equipment manufacturing cost (pressure vessel by bear pressure graduation, pressure is the highest, consumptive material is the most, the highest to bubble-tight requirement), it may be preferred to while be slowly added into a certain reactant (control reaction rate) limit to discharge CO by air valve₂So that the pressure stability in reaction vessel is in certain level.And use limit conveying material limit release CO₂Method be also beneficial to improve the production capacity of reactor in actual production.As consersion unit used by the inventive method, however, it would be possible to use all be applicable to liquid reactive container and pressure vessel.The material of container need to select according to the physico-chemical property of reactant, it is preferred to use has in the material of characteristic acidproof, alkaline-resisting, such as rustless steel (such as 316L rustless steel) pressure vessel or titanium material pressure vessel and carries out.

According to one embodiment of the present invention, the cationic structural of the quaternary ammonium salt of synthesis can be selected from following structure, but be not limited to following structure:

R, R in above-mentioned nitrogen-containing compound structure ', R₁、R₂、R₃、R₄、R₅、R₆It is independently selected from selected from containing hydrocarbon alkyl, thiazolinyl, alkynyl, phenyl, aryl；Or it is independently selected from the organic group of at least one element in boracic, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, bromine and iodine.R、R’、R₁、R₂、R₃、R₄、R₅、R₆Structure can be identical, it is also possible to different；R、R’、R₁、R₂、R₃、R₄、R₅、R₆Can be independent substituted radical, it is also possible to be that adjacent group combines cyclization.

According to one embodiment of the present invention, the cationic structural of the quaternary alkylphosphonium salt of synthesis can be selected from following structure, but be not limited to following structure:

Following structure can be selected from according to one embodiment of the present invention, the quaternary ammonium salt of synthesis or the anion structure of quaternary salt, but be not limited to following structure:

PF₆ ^-, BF₄ ^-, SO₄ ^2-, NO₃ ^-, F^-, Cl^-, Br^-, I^-, PO₄ ^3-, ClO₄ ^-, SiF₆ ^2-,

Second purpose of the present invention is to provide a kind of electrolyte for secondary cell, the ionic liquid prepared including the preparation method of the most any of the above-described ionic liquid.

At present, ionic liquid electrolyte is applied to the subject matter that lithium ion battery faces has: 1) with carbon based negative electrodes material such as graphite poor compatibility, it is impossible to carry out reversible polarization, it is difficult to show preferable embedding lithium/take off lithium performance；2) purity of ionic liquid is the highest, general by taking synthesizing cationic salt by alkyl halide quaternary salts tertiary amine compound, it is further used as the acid for anion (HA) or salt (MA) synthesized by anion exchange, the ionic liquid synthesized by this method, the problem that there is halogen ion residues, ionic liquid remains halogen ion, the biggest on its application impact in the secondary battery, halogen ion meeting corrosion cell shell, collector, lug etc., cause the calendar life of battery and cycle life to decline；3) to nonpolar, low porosity commercial PP/PE/PP barrier film wettability is poor, limits the performance of ionic liquid electrolyte, the lithium secondary battery making electrochemical properties deteriorate can not get actual application；4) being used as positive electrode active materials when lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminium composite oxide, have catalysed oxidn to ionic liquid, in battery, side reaction increases, and appearance is bulge or flatulence, causes circulating battery stability degradation；5) ionic liquid electrolyte corrosion to aluminum collector, current commodity electrolyte (carbonic ester and LiPF₆System) in aluminium oxide containing trace HF, HF and aluminum collection liquid surface react and generate AlF₃Protecting film; suppression aluminum is corroded; but; in ionic liquid (anion is double (trimethyl fluoride sulfonyl) imines ions or double fluorine sulfimide ion) electrolyte; under generic condition; will not form AlF3 protecting film at aluminum collection liquid surface, aluminum collector is corroded unavoidably.

In order to realize ionic liquid electrolyte application on graphite cathode, Chinese patent (patent publication No. is CN102138235A) proposes a solution, positive electrode active materials LiFePO₄, ionic liquid electrolyte adds 1%-10% vinyl ethylene carbonate (VEC), thus obtains the accumulator having good Reversible Cycle performance, overthrown " using ionic liquid electrolyte to be impossible for graphitic carbon electrode " this judgement.But, it is LiFePO that this solution is only limitted to positive pole₄Material, active positive electrode material higher for oxidizing potential, such as lithium nickel cobalt manganese oxide or lithium nickel cobalt aluminium composite oxide, the program does not have feasibility.In order to improve the compatibility of ionic liquid electrolyte and barrier film, (i.e. the base material of this specific barrier film is polar organic polymers, and structure is porous three-dimensional mesh for Chinese patent (patent publication No. is CN102903954A) the research component of ionic liquid electrolyte, raw material and feature and specific barrier film；There is the air penetrability of 150～500S/100CC) synergism with play respective sharpest edges to reach to improve ionic liquid high-rate performance.But, this patent only focuses on mating of ionic liquid electrolyte and barrier film, does not combine the characteristics such as positive pole, negative pole, collector, proposes total solution.Additionally, many documents mention that ionic liquid electrolyte is applied to lithium ion battery to improve safety, but seldom specific requirement is proposed the residual quantity of the purity especially halide ion of ionic liquid electrolyte.

In order to solve the problems referred to above, the 3rd purpose of the present invention is to provide a kind of secondary cell, and including positive pole, negative pole, barrier film and electrolyte, described electrolyte comprises the ionic liquid prepared such as the preparation method of above-mentioned ionic liquid.The ionic liquid purity using the inventive method to prepare is the highest, the problem that there is not halogen ion residues, substantially increases the service life of secondary cell.

Ionic liquid remains halogen ion, the biggest on its application impact in the secondary battery.Halogen ion meeting corrosion cell shell, collector, lug etc., affect the cycle characteristics of secondary cell, shorten cycle life.Chinese patent (Publication No. CN101379653) highlights the importance of ionic liquid electrolyte purity, and has made halide ion impurity content to limit, but does not point out how to obtain the ionic liquid entirely without halogen ionic impurity.The invention provides a kind of carbonic ester and make the alkylating reagent method by single step reaction synthesis ionic liquid.Such as shown in embodiment 14, with N-n-pro-pyl pyrrolidine, dimethyl carbonate and double (trimethyl fluoride sulfonyl) imines as reactant, by double (trimethyl fluoride sulfonyl) inferior amine salt of one-step synthesis method 1-methyl isophthalic acid-propyl pyrrole alkane.Owing to synthetic route being not related to halogenated hydrocarbons, it is to avoid anion exchange reaction, therefore, will not residual halogens ion and alkali metal ion in the ionic liquid of synthesis.After being configured to ionic liquid electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than or equal to 5ppm.

Cation preferred 1-methyl isophthalic acid-propyl pyrrole alkane ion, 1-methyl isophthalic acid-butyl pyrrolidine ion, 1-methyl isophthalic acid-propylpiperdine ion or the 1-methyl isophthalic acid-butyl piperidine ion of intermediate ion liquid of the present invention.nullIn addition，Find through many experiments，The present invention preferably makees the alkylating reagent method by single step reaction synthesis ionic liquid with carbonic ester，When tertiary amine is pyrrolidine or piperidines，Yield is higher，Such as embodiment 14，N-n-pro-pyl pyrrolidine (500g) is placed in pressure vessel together with 1000mL dimethyl carbonate，Protect with nitrogen，It is slowly added into double (trimethyl fluoride sulfonyl) imines (1243g)，Keep temperature less than 60 DEG C in the process，After adding，React 20 hours under 150 DEG C and about 1.6MPa，Course of reaction releases portion gas in order to avoid hypertonia by vent valve，After having reacted, decompression removes low boilers washed product，Double (trimethyl fluoride sulfonyl) inferior amine salt of N-Methyl-N-propyl pyrrolidine is obtained after vacuum drying，Yield is up to more than 98%.As preferably, in order to obtain the ionic liquid of high-purity low cost, the cation of ionic liquid of the present invention is preferably pyrrolidinium ions, piperidines ion.In theory, using carbonic ester to make alkylating reagent and can avoid the introducing of halide ion completely, i.e. in ionic liquid electrolyte, content of halide ions is zero.But owing to raw material, such as pyrrolidine, piperidines and carbonic ester there may be the pollution of halide ion, therefore, application claims distilation pyrrolidine, piperidines and carbonic ester before the reaction in process of production, in raw material, content of halide ions is less than 3ppm.It is presently used for the electrolyte of lithium secondary battery, carbonic ester/LiPF₆In system, moisture is down to 5ppm by 20ppm before the several years.Moisture is extremely serious to the performance impact of lithium battery, and the water of a part at least produces a part HF, and HF is the main inducing of lithium secondary battery internal resistance rising, aerogenesis bulge etc..Halide ion is no less than moisture to the harm of battery performance, and therefore, in ionic liquid electrolyte, the content to halide ion also should require to below 5ppm, to meet the long-life requirement of this secondary cell.

As preferably, described electrolyte includes lithium salts and basic components；Described basic components includes ionic liquid；The cation of described ionic liquid is selected from following structure at least one:

Wherein, R is alkyl.

The cation of preferred ion liquid is pyrrolidinium ions or piperidines ion, on the one hand, five-ring heterocycles, hexa-member heterocycle Stability Analysis of Structures, is conducive to extending the life-span of secondary cell；On the other hand, different from common quaternary ammonium ion, two substituent group associating cyclization in atom N, reduce between four substituent groups is sterically hindered, reduce and replace mutual " winding ", the beneficially decline of ionic liquid viscosity between alkyl, thus improve ionic liquid electrolyte high rate during charging-discharging.

As preferably, described cation is at least one in 1-methyl isophthalic acid-propyl pyrrole alkane ion, 1-methyl isophthalic acid-butyl pyrrolidine ion, 1-methyl isophthalic acid-propylpiperdine ion and 1-methyl isophthalic acid-butyl piperidine ion.

As preferably, the removal lithium embedded current potential of negative active core-shell material is not less than 0.25V (to Li/Li⁺)。

As preferably, described negative active core-shell material is silicon carbon material or aluminosilicate alloy material；Described silicon carbon material is wrapped

The carbon contained is not graphite.

As preferably, described aluminosilicate alloy material is at least one in copper silicon sill and silicon tin-based material.

As preferably, described negative active core-shell material is titanium-based oxide.

As preferably, described titanium-based oxide is Li-Ti oxide.

As preferably, the content≤5ppm of halide ion in described electrolyte.

As preferably, described lithium salts in lithium hexafluoro phosphate, LiBF4, trifluoromethyl sulfonic acid lithium, lithium perchlorate, hexafluoroarsenate lithium, double (catechol) Lithium biborate, dimalonic acid boric acid, di-oxalate lithium borate, three (catechol) lithium phosphate, three (perfluoro-ethyl) three lithium fluophosphate, trifluoromethyl sulfonic acid lithium, in double (trimethyl fluoride sulfonyl) imine lithium and double fluorine sulfimide lithium at least one.

As preferably, described lithium salts is selected from the first lithium salts at least one and the second lithium salts at least one；The first lithium salts described includes trifluoromethyl sulfonic acid lithium, double (trimethyl fluoride sulfonyl) imine lithium and double fluorine sulfimide lithium；Described the second lithium salts includes lithium hexafluoro phosphate and LiBF4.As further preferably, the quality of the first lithium salts described accounts for the 0.5～30% of described electrolyte gross mass；The quality of described the second lithium salts accounts for the 0.5～30% of described electrolyte gross mass.

As preferably, the first described lithium salts is 1:19～19:1 with the mol ratio of the second lithium salts.As further preferably, the first lithium salts described is 1:9～9:1 with the mol ratio of the second lithium salts.As further preferred, the first described lithium salts is 3:7～7:3 with the mol ratio of the second lithium salts.

Why select two or more lithium salts, be on the one hand because the physical property using mixing lithium salts can adjust ionic liquid electrolyte, such as, reduce fusing point, widen it and use temperature range；On the other hand, the second lithium salts lithium hexafluoro phosphate or LiBF4 can hydrolyze in the presence of minor amount of water, produce the Al of trace HF, HF and aluminum collection liquid surface₂O₃React generation AlF₃, thus protect collector from corrosion.Owing to lithium hexafluoro phosphate industrial manufacture process is ripe, production scale is big, and cost has dropped to the limit, therefore, in the composition of mixing lithium salts, lithium hexafluoro phosphate is preferably used, and uses more amount lithium hexafluoro phosphate as far as possible.But, more in the case of, use more amount lithium hexafluoro phosphate to may result in the physico-chemical property of ionic liquid electrolyte and change.Such as, crystallization under low temperature.Lithium hexafluoro phosphate usage amount number have close ties with the anion structure of ionic liquid.If anion is double (trimethyl fluoride sulfonyl) imines ions, the usage amount of lithium hexafluoro phosphate can suitably increase；If anion is trifluoromethane sulfonic acid root, the usage amount of lithium hexafluoro phosphate to be lacked as far as possible, LiBF4 be preferably used.Certainly, in order to regulate physico-chemical property and the electrochemical properties of ionic liquid electrolyte, it is also possible to adding the third lithium salts, the third lithium salts can play a role as electrolyte, it is also possible to plays a role as additive.In ionic liquid electrolyte, such as add the lithium salts such as a small amount of LiBOB, LiODBF, the SEI film that performance is special can be formed on silicon-based anode surface.

As preferably, described basic components also includes organic solvent；Described organic solvent is at least one in carbonates, carboxylic acid esters, sulfurous esters, sulfonic acid esters, sulfone class, ethers, silicone, nitrile and fluoro phosphine nitrile.As further preferably, described organic solvent is methyl carbonic acid propylene, ethyl carbonate propylene, methyl carbonic acid phenol ester, ethylene carbonate, halogenated ethylene carbonate, Allyl carbonate, butylene, dimethyl carbonate, diethyl carbonate, Ethyl methyl carbonate, methyl propyl carbonate, vinylene carbonate, ethylene sulfite, propylene sulfite, butylene sulfite, dimethyl sulfite, sulfurous acid diethyl ester, dimethyl sulfoxide, second methyl sulfoxide, 1, 3-N-morpholinopropanesulfonic acid ester, 1, 4-butyl sultone, dioxolanes, dimethoxy propane, ethyoxyl five fluorine phosphine nitrile, phenoxy group five fluorine phosphine nitrile, in adiponitrile and succinonitrile at least one.

As preferably, described basic components also includes that film former, described film former are sulfur dioxide, ethylene sulfite (VS), vinylene carbonate (VC), sulfite, sulfoxide, sulphonic acid ester, halo organic ester, the organic unsaturated compound containing ethenylidene, organic boride, Li₂CO₃And in LiBOB at least one.

As preferably, described basic components also includes functional additive；Described functional additive is at least one in anti-overcharge additive, flame-retardant additive, conductive additive and extreme-pressure additive.As further preferably, described functional additive be biphenyl (DP), cyclohexyl benzene, aromatic radical diamantane (obsolete), naphthalene derivatives, many polyphenyl, trimethyl phosphate (TMP), triphenyl phosphate (TPP), three (2,2,2 trifluoroethyls) phosphite ester, in phenodiazine (miscellaneous) benzene, three (five fluorinated phenyl) boron, ethyoxyl five fluorine phosphine nitrile, phenoxy group five fluorine phosphine nitrile, adiponitrile and succinonitrile at least one.

As preferably, described basic components includes the ionic liquid of 70～100wt%, the organic solvent of 0～30wt%, the film former of 0～10wt%, the functional additive of 0～10wt%.

As preferably, positive electrode active materials is selected from lithium nickel cobalt manganese oxide, lithium/nickel/cobalt composite oxide, lithium nickel cobalt aluminium composite oxide, li-mn-ni compound oxide, Lithium Phosphor Oxide, lithium and cobalt oxides and complex Li-Mn-oxide at least one.Described li-mn-ni compound oxide has spinel structure, and described Lithium Phosphor Oxide has olivine structural.

The positive active material that secondary cell of the present invention comprises is not particularly limited, it can be lithium nickel cobalt manganese oxide, lithium/nickel/cobalt composite oxide, lithium nickel cobalt aluminium composite oxide, spinel type lithium mn-ni compound oxide, there is at least one in the Lithium Phosphor Oxide of olivine structural, lithium and cobalt oxides and complex Li-Mn-oxide.The most not only can improve the running voltage of battery but also there is the material of high electrochemical stability, such as lithium nickel cobalt manganese oxide NCM (333), lithium nickel cobalt manganese oxide NCM (442), lithium nickel cobalt manganese oxide NCM (523) etc..

As preferably, described barrier film is at least one in ethylene glycol terephthalate barrier film, polyacrylonitrile barrier film and Kynoar barrier film.Ionic liquid is polar substances, selects the barrier film of polarity, contributes to electrolyte abundant moistening barrier film.

As preferably, the average pore size of described barrier film is 1～25 μm；The porosity of described barrier film is 50～85%.Barrier film porosity is high, and barrier film is big to the volume of holding of electrolyte, is suitable for very much the ionic liquid electrolyte that viscosity is bigger.

Accompanying drawing explanation

The charging curve of secondary cell prepared by Fig. 1 a embodiment of the present invention 14；

The discharge curve of secondary cell prepared by Fig. 1 b embodiment of the present invention 14；

The cycle life curve of secondary cell prepared by Fig. 2 embodiment of the present invention 14；

The discharge curve of secondary cell prepared by Fig. 3 embodiment of the present invention 15；

The discharge curve of secondary cell prepared by Fig. 4 embodiment of the present invention 16；

The charging curve of secondary cell prepared by Fig. 5 a embodiment of the present invention 17；

The discharge curve of secondary cell prepared by Fig. 5 b embodiment of the present invention 17；

The charging curve of secondary cell prepared by Fig. 6 a embodiment of the present invention 18；

The discharge curve of secondary cell prepared by Fig. 6 b embodiment of the present invention 18；

The charging curve of secondary cell prepared by Fig. 7 a embodiment of the present invention 19；

The discharge curve of secondary cell prepared by Fig. 7 b embodiment of the present invention 19；

The charging curve of secondary cell prepared by Fig. 8 a embodiment of the present invention 20；

The discharge curve of secondary cell prepared by Fig. 8 b embodiment of the present invention 20；

The charging curve of secondary cell prepared by Fig. 9 a comparative example of the present invention 1；

The discharge curve of secondary cell prepared by Fig. 9 b comparative example of the present invention 1；

The charging curve of secondary cell prepared by Figure 10 a comparative example of the present invention 2；

The discharge curve of secondary cell prepared by Figure 10 b comparative example of the present invention 2；

The cycle life curve of secondary cell prepared by Figure 11 comparative example of the present invention 3；

Tri-kinds of barrier film SEM figures of PVDF, PET, PP/PE/PP that Figure 12 embodiment of the present invention uses.

Detailed description of the invention

The present invention is described in detail by following specific embodiment, but the present invention is not restricted to following example.

Lithium rechargeable battery structure is not construed as limiting by the present invention, can be column type, square or coin shape, flexible package or box hat or aluminum hull.The embodiment of the present invention uses buckle type lithium-ion secondary cell (CR2025) and flexible packing lithium ion battery.The positive electrode active materials of battery is also not construed as limiting, positive electrode active materials can be selected from lithium nickel cobalt manganese oxide, lithium/nickel/cobalt composite oxide, lithium nickel cobalt aluminium composite oxide, spinel type lithium mn-ni compound oxide, there is at least one in the Lithium Phosphor Oxide of olivine structural, lithium and cobalt oxides or complex Li-Mn-oxide.The removal lithium embedded current potential of negative active core-shell material is not less than 0.25V (to Li/Li⁺), can be selected from the material in addition to the carbon materialses such as graphite (native graphite or electrographite), such as lithium titanate, elemental silicon, carbon-silicon composite material, copper silicon composite, silicon-tin composite material etc..

Embodiment 1:

Triethylamine (606g) is placed in pressure vessel together with 1000mL dimethyl carbonate, protects with nitrogen.Being passed through concentrated sulphuric acid (300g, 98%) under cooling measure, after adding sulphuric acid, be warming up to 200 DEG C, in course of reaction, pressure can rise, if reaction pressure is more than 3.0Mpa, in keeping still by valve venting, pressure no longer rises.0.2 hour response time.After reaction terminates and is down to room temperature, decompression removes low boilers washed product, obtains N-methyl-N-triethyl group ammonium sulfate (950g).

Embodiment 2:

N-n-pro-pyl pyrrolidine (500g) is placed in pressure vessel together with 1000mL dimethyl carbonate.Protect with nitrogen, be slowly added into double (trimethyl fluoride sulfonyl) imines (1234g), keep temperature less than 60 DEG C in the process.After adding, reacting 20 hours under 150 DEG C and about 1.6MPa, course of reaction releases portion gas in order to avoid hypertonia by vent valve.After having reacted, decompression removes low boilers washed product, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (1675g) of N-Methyl-N-propyl pyrrolidine.

Embodiment 3:

N-n-pro-pyl pyrrolidine (500g) is placed in pressure vessel together with 500g dimethyl carbonate, 500mL methanol, it is warming up to 120 DEG C, then adding double (trimethyl fluoride sulfonyl) imines (1236g) by certain flow, in reaction vessel, temperature keeps 120～130 DEG C in the process.Continuing feed time is 12 hours, after terminating by double (trimethyl fluoride sulfonyl) the imines material of set amount conveying, is warming up to 150 DEG C and continues reaction 2 hours.In course of reaction, if reaction pressure is more than 2.6Mpa, in keeping still by valve venting, pressure no longer rises.After reaction terminates and is down to room temperature, decompression removes low boilers washed product, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (1704g) of N-Methyl-N-propyl pyrrolidine.

Embodiment 4:

N-n-butylpyrrolioine (500g) is placed in pressure vessel, protects with nitrogen, keep temperature less than 60 DEG C, be slowly added into the mixture of trifluoromethanesulfonic acid (585g) and 1000mL dimethyl carbonate.After adding, reacting 15 hours under 140 DEG C and about 1.5MPa, course of reaction releases portion gas in order to avoid hypertonia by vent valve.After having reacted, decompression removes low boilers, obtains N-methyl-N-n-butylpyrrolioine fluoroform sulphonate (1006g).

Embodiment 5:

N-ethyl imidazol(e) (298g) is placed in pressure vessel, is slowly added into Tetrafluoroboric acid methanol solution (682g, 40%), keep temperature less than room temperature in the process.After adding, adding 600mL dimethyl carbonate, whole process nitrogen is protected.Rising high-temperature to 180 DEG C, react 3 hours under about 1.5MPa, course of reaction releases portion gas in order to avoid hypertonia by vent valve.After having reacted, decompression removes low boilers, obtains 1-methyl-3-ethyl imidazol(e) tetrafluoroborate (574g).

Embodiment 6:

Under nitrogen protection, double (trimethyl fluoride sulfonyl) imines (125g) are placed in pressure vessel, are slowly added into tri-n-butyl phosphine (89g) and 150mL dimethyl carbonate, keep temperature less than room temperature in the process.After adding, liter high-temperature, to 180 DEG C, reacts 5 hours under about 1.5MPa, and after having reacted, decompression removes low boilers, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (214g) of methyl three normal-butyl.

Embodiment 7:

Under nitrogen protection; triphenylphosphine (115g), 150mL dimethyl carbonate are placed in pressure vessel together with double (trimethyl fluoride sulfonyl) imines (125g); rise high-temperature to 180 DEG C; react 4 hours under about 1.5MPa; after having reacted, decompression removes low boilers, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (240g) of methyl triphenyl.

Embodiment 8:

Under nitrogen protection, triphenylphosphine (115g) and double (trimethyl fluoride sulfonyl) imines (125g) are placed in pressure vessel, add 150mL diethyl carbonate.After adding, liter high-temperature, to 180 DEG C, reacts 5 hours under about 2.5MPa, and after having reacted, decompression removes low boilers, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (236g) of ethyl triphenyl.

Embodiment 9:

Under nitrogen protection, double (trimethyl fluoride sulfonyl) imines (152g) are placed in pressure vessel, are slowly added into diphenylphosphine (100g) and 150mL diethyl carbonate.After adding, liter high-temperature, to 180 DEG C, reacts 5 hours under about 2.0MPa, and after having reacted, decompression removes low boilers, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (262g) of diethyl diphenyl.

Embodiment 10:

Under nitrogen protection, 1-Aminooctane (100g) and 250mL dimethyl carbonate are placed in pressure vessel, are slowly added into concentrated sulphuric acid (39g, 98%), control temperature less than 60 DEG C.After adding, liter high-temperature, to 180 DEG C, reacts 8 hours under about 0.5MPa, and after having reacted, decompression removes low boilers, obtains trimethyloctyl ammonium sulfate (159g).

Embodiment 11:

Under nitrogen protection; dioctylamine (1200g) and 2000mL dimethyl carbonate are placed in pressure vessel; slowly it is passed through hydrogen chloride gas (180g); keep course of reaction temperature less than 60 DEG C; after adding, liter high-temperature, to 160 DEG C, reacts 20 hours under about 0.2MPa; after having reacted, decompression removes low boilers, obtains dimethyl dioctyl ammonium salt hydrochlorate (1070g).

Embodiment 12:

Under argon shield; by tributylphosphine (100g), 100g ethylene carbonate and ethanol solution of hydrogen chloride (55g; 33%) it is placed in together in pressure vessel; rise high-temperature to 160 DEG C; react 3 hours under about 1.5MPa; after having reacted, decompression removes low boilers, obtains 2-ethoxy tributyl hydrochlorate (138g).

Embodiment 13:

N-hexylamine (300g) is placed in pressure vessel together with 500g dimethyl carbonate, is warming up to 120 DEG C, then add double (fluorine sulphonyl) imines (538g) by certain flow, then heat to 160 DEG C and continue reaction 3 hours.In course of reaction, if reaction pressure is more than 1.6Mpa, in keeping still by valve venting, pressure no longer rises.After reaction terminates and is down to room temperature, decompression removes low boilers washed product, obtains double (fluorine sulphonyl) inferior amine salt (753g) of trimethyl n-hexyl ammonium.

Embodiment 14:

The synthesis of ionic liquid: N-n-pro-pyl pyrrolidine (500g) is placed in pressure vessel together with 1000mL dimethyl carbonate.Protect with nitrogen, be slowly added into double (trimethyl fluoride sulfonyl) imines (1243g), keep temperature less than 60 DEG C in the process.After adding, reacting 20 hours under 150 DEG C and about 1.6MPa, course of reaction releases portion gas in order to avoid hypertonia by vent valve.After having reacted, decompression removes low boilers washed product, obtains double (trimethyl fluoride sulfonyl) inferior amine salt of N-Methyl-N-propyl pyrrolidine after vacuum drying.

The preparation of ionic liquid electrolyte: double (trimethyl fluoride sulfonyl) inferior amine salt (Pr of N-Methyl-N-propyl pyrrolidine_1,3TFSI) it is mixed into homogeneous phase solution with Allyl carbonate (PC) 85:15 in mass ratio, is subsequently adding LiPF₆And double (trimethyl fluoride sulfonyl) imines lithium salts (LiTFSI), two kinds of lithium salts mol ratios 1:7, form 0.8mol/L (M/L) electrolyte solution after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel-cobalt-manganese ternary (523), and negative material is lithium titanate Li to take active electrode material respectively₄Ti₅O₁₂(LTO)), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, is die-cut into pole piece.Barrier film selects ethylene glycol terephthalate barrier film (PET barrier film), average pore size > 1 μm, porosity > 65%.It is assembled into flexible-packed battery, design capacity 5Ah in the strict drying shed controlling humidity.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.2C, constant-current discharge multiplying power 0.2C, investigates its capacity capability development, sees Fig. 1 a and Fig. 1 b.Under 45 DEG C of ambient temperatures, by the discharge and recharge in 2.0V～2.8V voltage range of above-mentioned flexible-packed battery, charge-discharge magnification 0.2C, investigate its cyclical stability, see Fig. 2.

Embodiment 15:

The synthesis of ionic liquid is with embodiment 14.

The preparation of ionic liquid electrolyte: double (trimethyl fluoride sulfonyl) inferior amine salt (Pr of N-Methyl-N-propyl pyrrolidine_1,3TFSI) Allyl carbonate (PC), fluorinated ethylene carbonate (FEC), vinylene carbonate (VC) 85:10:3:2 in mass ratio are mixed into homogeneous phase solution, are subsequently adding LiPF₆And double (trimethyl fluoride sulfonyl) imines lithium salts (LiTFSI), two kinds of lithium salts mol ratios 4:4, form 0.8M/L electrolyte solution after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel cobalt aluminum (NCA to take active electrode material respectively, Ni:Co:Al=80:15:5, negative material is Si-C composite material), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, is die-cut into pole piece.Barrier film selects PET barrier film, average pore size > 1 μm, porosity > 65%.It is assembled into flexible-packed battery, design capacity 5Ah in the strict drying shed controlling humidity.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 2.5V～4.1V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.1C, and constant-current discharge multiplying power 0.1C is investigated its discharge performance, seen Fig. 3.

Embodiment 16:

The synthesis of ionic liquid and the preparation of ionic liquid electrolyte are with embodiment 14, except for the difference that, during the preparation of ionic liquid electrolyte, use sultones (1,3-PS) to replace vinylene carbonate (VC).

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel-cobalt-manganese ternary (523) to take active electrode material respectively, negative material is copper silicon composite), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, it is die-cut into pole piece.Barrier film selects PET barrier film, average pore size > 1 μm, porosity > 65%.It is assembled into flexible-packed battery, design capacity 4Ah in the strict drying shed controlling humidity.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 2.5V～4.1V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.1C, and constant-current discharge multiplying power 0.1C is investigated its discharge performance, seen Fig. 4.

Embodiment 17:

The synthesis of ionic liquid: N-n-pro-pyl pyrrolidine (500g) is placed in pressure vessel together with 500g dimethyl carbonate, 500mL methanol, it is warming up to 120 DEG C, then adding double (trimethyl fluoride sulfonyl) imines (1243g) by certain flow, in reaction vessel, temperature keeps 120～130 DEG C in the process.Continuing feed time is 12 hours, after terminating by double (trimethyl fluoride sulfonyl) the imines material of set amount conveying, is warming up to 150 DEG C and continues reaction 2 hours.In course of reaction, if reaction pressure is more than 2.6Mpa, in keeping still by valve venting, pressure no longer rises.After reaction terminates and is down to room temperature, decompression removes low boilers washed product, obtains double (trimethyl fluoride sulfonyl) inferior amine salt of N-Methyl-N-propyl pyrrolidine.

The preparation of ionic liquid electrolyte: double (trimethyl fluoride sulfonyl) inferior amine salt (Pr of N-Methyl-N-propyl pyrrolidine_1,3TFSI) it is mixed into homogeneous phase solution with ethylene carbonate (EC) 90:10 in mass ratio, is subsequently adding LiPF₆And double (trimethyl fluoride sulfonyl) imines lithium salts (LiTFSI), two kinds of lithium salts mol ratios 1:7, form 0.8M/L electrolyte solution after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel-cobalt-manganese ternary (523), and negative material is lithium titanate Li to take active electrode material respectively₄Ti₅O₁₂), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, is die-cut into pole piece.Barrier film selects PET barrier film, average pore size > 1 μm, porosity > 65%.It is assembled into flexible-packed battery, design capacity 5Ah in the strict drying shed controlling humidity.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.2C, and constant-current discharge multiplying power 0.2C investigates its charging and discharging capabilities, sees Fig. 5 a and Fig. 5 b.

Embodiment 18:

The synthesis of ionic liquid: be placed in pressure vessel by N-n-butylpyrrolioine (500g), protects with nitrogen, keeps temperature less than 60 DEG C, is slowly added into the mixture of trifluoromethanesulfonic acid (663g) and 1000mL dimethyl carbonate.After adding, reacting 15 hours under 140 DEG C and about 1.5MPa, course of reaction releases portion gas in order to avoid hypertonia by vent valve.After having reacted, decompression removes low boilers, obtains N-methyl-N-n-butylpyrrolioine fluoroform sulphonate.

The preparation of ionic liquid electrolyte: N-methyl-N-butyl pyrrolidine trifluoromethyl sulfonic acid (Pr_1,4OTf) it is mixed into homogeneous phase solution with Allyl carbonate (PC) 70:30 in mass ratio, is subsequently adding LiBF₄And trifluoromethyl sulfonic acid lithium salt (LiOTf), two kinds of lithium salts mol ratios 9:1, form 1.0M/L electrolyte solution after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.2C, and constant-current discharge multiplying power 0.2C investigates its charging and discharging capabilities, sees Fig. 6 a and Fig. 6 b.

Embodiment 19

The synthesis of ionic liquid: N-n-butylpiperidine is placed in pressure vessel together with dimethyl carbonate in molar ratio 1:3, it is warming up to 120 DEG C, then add double (fluorine sulphonyl) imines (N-n-butylpiperidine is 1:1 with the mol ratio of double (fluorine sulphonyl) imines) by certain flow, then heat to 160 DEG C and continue reaction 3 hours.In course of reaction, if reaction pressure is more than 1.6Mpa, in keeping still by valve venting, pressure no longer rises.After reaction terminates and is down to room temperature, decompression removes low boilers washed product, obtains double (fluorine sulphonyl) inferior amine salt (Py of N-methyl-N-n-butylpiperidine after vacuum drying_1,4FSI)。

The preparation of ionic liquid electrolyte: double (fluorine sulphonyl) inferior amine salt (Py of N-methyl-N-n-butylpiperidine_1,4FSI), it is subsequently adding LiPF₆And double (fluorine sulphonyl) imines lithium salts (LiFSI), two kinds of lithium salts mol ratios 1:9, form 1.0M/L electrolyte after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.5C, and constant-current discharge multiplying power 0.5C investigates its charging and discharging capabilities, sees Fig. 7 a and Fig. 7 b.

Embodiment 20

The synthesis of ionic liquid is with embodiment 19.

The preparation of ionic liquid electrolyte: double (fluorine sulphonyl) inferior amine salt (Py of N-methyl-N-n-butylpiperidine_1,4FSI) mix with Allyl carbonate (PC) 95:5 in mass ratio, be subsequently adding LiPF₆And double (fluorine sulphonyl) imines lithium salts (LiFSI), two kinds of lithium salts mol ratios 1:9, form 1.0M/L electrolyte after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel-cobalt-manganese ternary (523), and negative material is lithium titanate Li to take active electrode material respectively₄Ti₅O₁₂), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, is die-cut into pole piece.Barrier film selects polyvinyladine floride (PVDF) barrier film, average pore size > 1 μ 1, porosity > 60%.It is assembled into flexible-packed battery, design capacity 5Ah in the strict drying shed controlling humidity.

Battery performance test: under 45 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 1C, and constant-current discharge multiplying power 1C investigates its charging and discharging capabilities, sees Fig. 8 a and Fig. 8 b.

Comparative example 1

The synthesis of ionic liquid is with embodiment 14.

The preparation of ionic liquid electrolyte: double (trimethyl fluoride sulfonyl) inferior amine salt (Pr of N-Methyl-N-propyl pyrrolidine_1,3TFSI) it is mixed into homogeneous phase solution with Allyl carbonate (PC), vinylene carbonate (VC) 85:10:5 in mass ratio, is subsequently adding LiPF₆And double (trimethyl fluoride sulfonyl) imines lithium salts (LiTFSI), two kinds of lithium salts mol ratios 1:7, form 0.8M/L electrolyte solution after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, halogen ion (Cl^-, Br^-, I^-) content less than 5ppm.

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel-cobalt-manganese ternary (523) to take active electrode material respectively, negative material is graphite), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, it is die-cut into pole piece.Barrier film selects PET barrier film, average pore size > 1 μm, porosity > 65%.It is assembled into flexible-packed battery, design capacity 10Ah in the strict drying shed controlling humidity.

Battery performance test: under 45 DEG C of ambient temperatures, by the discharge and recharge in 3.0V～4.2V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.2C, and constant-current discharge multiplying power 0.2C investigates its charge-discharge performance, sees Fig. 9 a and Fig. 9 b.

Comparative example 2

The synthesis of ionic liquid is prepared with embodiment 20 with ionic liquid electrolyte.

The assembling of rechargeable nonaqueous electrolytic battery: (positive electrode is nickel-cobalt-manganese ternary (523), and negative material is lithium titanate Li to take active electrode material respectively₄Ti₅O₁₂), conductive agent (conductive black), binding agent (PVDF) compare mix homogeneously by certain mass, add solvent N-methyl pyrilidone, mix homogeneously further, it is configured to the slurry that solid content is 60%, then coat on Al paper tinsel collector, roll-in after drying, is die-cut into pole piece.Barrier film selects PP/PE/PP barrier film, average pore size < 1 μm, porosity < 50%.It is assembled into flexible-packed battery, design capacity 5Ah in the strict drying shed controlling humidity.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.2C, and constant-current discharge multiplying power 0.2C investigates its charge-discharge performance, sees Figure 10 a and Figure 10 b.

Comparative example 3

The synthesis of ionic liquid: first by N-crassitude (500g) and 1000mL N-Propyl Bromide generation substitution reaction, it is subsequently adding double (trimethyl fluoride sulfonyl) imide (1243g) and carries out anion exchange reaction, keep temperature less than 60 DEG C in the process.After having reacted, decompression removes low boilers washed product, obtains double (trimethyl fluoride sulfonyl) inferior amine salt (Pr of N-Methyl-N-propyl pyrrolidine after vacuum drying_1,3TFSI)。

The preparation of ionic liquid electrolyte: double (trimethyl fluoride sulfonyl) inferior amine salt (Pr of N-Methyl-N-propyl pyrrolidine_1,3TFSI) it is mixed into homogeneous phase solution with Allyl carbonate (PC) 85:15 in mass ratio, is subsequently adding LiPF₆And double (trimethyl fluoride sulfonyl) imines lithium salts (LiTFSI), two kinds of lithium salts mol ratios 1:7, form 0.8M/L electrolyte solution after dissolving.Being detected by chromatography of ions and ICP means and analyze, result shows in electrolyte, and the alkali-metal content as impurity is more than 300ppm more than 300ppm, the content as halogen ion.

Battery performance test: under 25 DEG C of ambient temperatures, by the discharge and recharge in 1.0V～2.8V voltage range of above-mentioned flexible-packed battery, constant-current charge multiplying power is 0.2C, constant-current discharge multiplying power 0.2C, investigates its capacity capability development, sees Figure 11.

Rechargeable nonaqueous electrolytic battery composition in table 2 various embodiments of the present invention 14 to embodiment 20 and comparative example 1 to comparative example 3

In table 1, E represents the ionic liquid in electrolyte basic components, and F represents the organic solvent in electrolyte basic components, G and H represents the functional additive in electrolyte basic components or film former.The present invention devises three groups of comparative examples, respectively comparative example 1, comparative example 2 and comparative example 3 as shown in Table 1；Wherein, comparative example 1 mainly verifies the impact using graphite cathode to be brought；Comparative example 2 mainly verifies and uses the impact that brought of nonpolar barrier film, and comparative example 3 is mainly verified the impact that ionic liquid prepared by anionexchangetechnique method (halogen ion > 300ppm) is brought.

Comparing embodiment 14, embodiment 15, embodiment 16, embodiment 17, embodiment 18, embodiment 19, embodiment 20 and comparative example 1, it can be seen that the active substance comprised when negative pole is that removal lithium embedded current potential electromotive force is not less than 0.25V (to Li/Li⁺) material time, use the ionic liquid prepared of the inventive method and the electrolyte solution of preparation, it is possible to achieve the normal discharge and recharge of battery, rated capacity can have been given play under 25 DEG C of ambient temperatures.When the active substance of negative pole is that (removal lithium embedded current potential electromotive force is less than 0.25V (to Li/Li to graphite⁺)) time, battery charging and discharging occurs abnormal, can not put rated capacity, and bulge phenomenon occurs in battery, finds that the coating layer of active substance on cathode pole piece is peeled off from collector, come off after disassembling battery.It is indicated above, when in secondary cell, positive electrode active materials is lithium nickel cobalt manganese oxide or lithium/nickel/cobalt composite oxide, negative electrode active material is preferably selected the one of which such as lithium titanate, elemental silicon, carbon-silicon composite material, copper silicon composite, silicon-tin composite material, and side can use ionic liquid electrolyte.If use graphite material, intercalation electromotive force due to ionic liquid cation is higher than the intercalation electromotive force of lithium ion, and i.e. when charging, ionic liquid cation, prior to Lithium-ion embeding graphite linings, blocks the passage of Lithium-ion embeding, even " strut " graphite linings, cause graphite linings to be peeled off.Even if this phenomenon also cannot be suppressed by adding the film former such as VC.

Claims

1. the preparation method of ionic liquid, it is characterised in that: synthesized ionic liquid by nitrogen-containing compound or phosphorus-containing compound, proton compound and carbonic ester by single step reaction；Described nitrogen-containing compound is selected from ammonia (NH₃), primary amine (RNH₂), secondary amine (R₁R₂And tertiary amine (R NH)₁R₂R₃N) at least one；Described phosphorus-containing compound is selected from hydrogen phosphide (PH₃), primary phosphine (RPH₂), secondary phosphine (R₁R₂And tertiary phosphine (R PH)₁R₂R₃P) at least one；Wherein, R₁、R₂、R₃It is independently selected from hydrogen, alkyl, thiazolinyl, alkynyl, phenyl or aryl；Or R₁、R₂、R₃It is independently selected from the organic group of at least one element in boracic, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, bromine and iodine；Described R₁、R₂、R₃For independent substituted radical；Or described R₁、R₂、R₃Cyclization is combined for adjacent group.

2. the preparation method of ionic liquid as claimed in claim 1, it is characterised in that: described nitrogen-containing compound is selected from following structure at least one:

；

Wherein, R₁、R₂、R₃、R₄、R₅、R₆It is independently selected from hydrogen, alkyl, thiazolinyl, alkynyl, phenyl or aryl；Or R₁、R₂、R₃、R₄、R₅、R₆It is independently selected from the organic group of at least one element in boracic, silicon, nitrogen, phosphorus, oxygen, sulfur, fluorine, chlorine, bromine and iodine；Described R₁、R₂、R₃、R₄、R₅、R₆For independent substituted radical；Or described R₁、R₂、R₃、R₄、R₅、R₆Cyclization is combined for adjacent group.

3. the preparation method of ionic liquid as claimed in claim 1, it is characterized in that: described phosphorus-containing compound is selected from methylphosphine, dimethylphosphine, three methylphosphines, ethyl phosphine, diethyl phosphine, triethyl phosphine, tripropyl phosphine, di-t-butyl phosphine, tri-butyl phosphine, tributylphosphine, three n-pentyl phosphines, cyclohexyl phosphine, dicyclohexylphosphontetrafluoroborate, tricyclohexyl phosphine, three hexyl phosphines, tri octyl phosphine, Phenylphosphine, diphenylphosphine, triphenylphosphine, dimethylphenylphosphine, diethyl Phenylphosphine, diphenyl butylphosphine, tribenzyl phosphine, tris hydroxymethyl phosphine, in 2-ethyl chloride diethyl phosphine and three (pentafluoroethyl group) phosphine at least one.

4. the preparation method of ionic liquid as claimed in claim 1, it is characterised in that: described proton compound is selected from inorganic oxacid, inorganic oxygen-free acid, organic acid and non-acids proton compound at least one.

5. the preparation method of ionic liquid as claimed in claim 4, it is characterised in that: described inorganic oxygen-containing is selected from meta-aluminic acid (HAlO₂), tetrahydroxy close aluminum (III) acid (HAl (OH)₄), arsenic acid (H₃AsO₄), metaarsenous acid (HAsO₂), arsenious acid (H₃AsO₃), pyroarsenic acid (H₄As₂O₇), boric acid (H₃BO₃), metaboric acid ((HBO₂)_n), tetraboric acid (H₂B₄O₇), perboric acid (HBO₃), 12 tungsten boric acid (H₅BW₁₂O₄₀), bromic acid (HBrO₃), bromous acid (HBrO₂), Hydrogen oxybromide (HOBr) (HBrO), hyperbromic acid (HBrO₄), orthocarbonic acid (H₄CO₄), cross two carbonic acid (H₂C₂O₆), percarbonic acid (H₂CO₄Or H₂CO₃·H₂O₂), chloric acid (HClO₃), perchloric acid (HClO₄), chlorous acid (HClO₂), hypochlorous acid (HClO), fulminic acid (HONC), cyanic acid (HOCN), Carbimide. (HNCO), iodic acid (HIO₃), Hypoiodous acid (HIO) (HIO or IOH), metaperiodic acid (HIO₄), periodic acid (H₅IO₆), burnt periodic acid (H₄I₂O₉), nitric acid (HNO₃), nitrous acid (HNO₂), phosphoric acid (H₃PO₄), former phosphoric acid (H₅PO₅), Metaphosphoric acid (HPO₃) n, phosphorous acid (H₃PO₃), pyrophosphorous acid (H₄P₂O₅), metaphosphorous acid (HPO₂), hypophosphorous acid (H₃PO₂), hypophosphoric acid (H₄P₂O₆), pyrophosphoric acid (H₄P₂O₇), sulphuric acid (H₂SO₄), sulfurous acid (H₂SO₃), thiosulfuric acid (H₂S₂O₃), pyrosulfuric acid (H₂S₂O₇), sulphoxylic acid (H₂SO₂), polythionic acid (H₂S_xO₆, x=2～6), ortho-sulfuric acid (H₆SO₆), hydrosulfurous acid (H₂S₂O₄), permonosulphuric acid (H₂SO₅), peroxy-disulfuric acid (H₂S₂O₈), chlorosulfonic acid (HSO₃Cl), fluosulfonic acid (HSO₃F), metasilicic acid (H₂SiO₃Or SiO₂·H₂O), orthosilicic acid (H₄SiO₄), two metasilicic acid (H₂Si₂O₅Or 2SiO₂·H₂O), three silicic acid (H₄Si₃O₈) and disilicic acid (H₆Si₂O₇Or 2SiO₂·3H₂O) at least one.

6. the preparation method of ionic liquid as claimed in claim 4, it is characterised in that: described inorganic oxygen-free acid is selected from carborane acid (H [CHB₁₁Cl₁₁]), hydrosulphuric acid (H₂S), Perthiocarbonate (H₂CS₄), thiocarbonic acid (H₂CS₃), hydrocyanic acid (HCN), selenium cyanic acid (HSeCN), Hydrogen thiocyanate (HSCN), fluoboric acid (HBF₄), hexafluosilicic acid (H₂SiF₆), hexafluorophosphoric acid (HPF₆), Fluohydric acid. (HF), hydrochloric acid (HCl), in hydrobromic acid (HBr) and hydroiodic acid (HI) at least one.

7. the preparation method of ionic liquid as claimed in claim 4, it is characterized in that: described organic acid is selected from oxalic acid, formic acid, acetic acid, propanoic acid, succinic acid, trifluoracetic acid, trifluoromethanesulfonic acid, methanesulfonic acid, mandelic acid, methylsulfuric acid, ethyl sulfuric acid, oleic acid, stearic acid, acrylic acid, maleic acid, citric acid, double (catechol) boric acid, double oxalic acid boric acid, dimalonic acid boric acid, three (pentafluoroethyl group) three fluorophosphoric acid, triethyl group three fluorophosphoric acid, four cyano boric acid, tartaric acid, malic acid, citric acid, ascorbic acid, benzoic acid, benzenesulfonic acid, p-methyl benzenesulfonic acid, in salicylic acid and caffeic acid at least one.

8. the preparation method of ionic liquid as claimed in claim 4, it is characterised in that: described non-acids proton compound is group with imine moiety；Described group with imine moiety has such as formula 1, formula 2 or the structure shown in formula 3:

Formula 1:HN (C_mF_2m+1SO₂)(C_nF_2n+1SO₂)；

Formula 2:HN (C_nF_2n+1SO₂)₂；

Formula 3:HN (C_xF_2xSO₂)₂；

9. the preparation method of ionic liquid as claimed in claim 8, it is characterised in that: described group with imine moiety is selected from following structural formula at least one:

10. the preparation method of ionic liquid as claimed in claim 4, it is characterized in that: described non-acids proton compound selected from three (trimethyl fluoride sulfonyl) methane, phenol, p-methyl phenol, betanaphthol, 2, in 4-chlorophenesic acid and mutual-amino phenol at least one.

The preparation method of 11. ionic liquids as claimed in claim 1, it is characterised in that: described carbonic ester is selected from dimethyl carbonate, Ethyl methyl carbonate, diethyl carbonate, ethylene carbonate, Allyl carbonate, phenyl-carbonic acid methyl ester, diphenyl carbonate and dimethyl benzyl at least one.

The preparation method of 12. ionic liquids as claimed in claim 11, it is characterised in that: described carbonic ester is selected from dimethyl carbonate, Ethyl methyl carbonate and diethyl carbonate at least one.

The preparation method of 13. ionic liquids as claimed in claim 1, it is characterised in that: it is 100～200 DEG C that the temperature of described single step reaction controls.

The preparation method of 14. ionic liquids as claimed in claim 13, it is characterised in that: it is 120～180 DEG C that the temperature of described single step reaction controls.

The preparation method of 15. ionic liquids as claimed in claim 14, it is characterised in that: it is 140～160 DEG C that the temperature of described single step reaction controls.

The preparation method of 16. ionic liquids as claimed in claim 1, it is characterised in that: it is 0.1～3.0Mpa that the absolute pressure of described single step reaction controls.

The preparation method of 17. ionic liquids as claimed in claim 16, it is characterised in that: it is 0.8～2.0Mpa that the absolute pressure of described single step reaction controls.

The preparation method of 18. ionic liquids as claimed in claim 17, it is characterised in that: it is 1.0～1.5Mpa that the absolute pressure of described single step reaction controls.

The preparation method of 19. ionic liquids as claimed in claim 1, it is characterised in that: it is 0.1～20 hour that the response time of described single step reaction controls.

The preparation method of 20. ionic liquids as claimed in claim 19, it is characterised in that: it is 4～15 hours that the response time of described single step reaction controls.

The preparation method of 21. ionic liquids as claimed in claim 20, it is characterised in that: it is 9～12 hours that the response time of described single step reaction controls.

22. electrolyte being used for secondary cell, comprise ionic liquid prepared by the preparation method of ionic liquid as described in any one of claim 1-21.

23. secondary cells, including positive pole, negative pole, barrier film and electrolyte, it is characterised in that: described electrolyte comprises ionic liquid prepared by the preparation method of ionic liquid as described in any one of claim 1-21.

24. secondary cells as claimed in claim 23, it is characterised in that: described electrolyte includes lithium salts and basic components；Described basic components includes ionic liquid；The cation of described ionic liquid is selected from following structure at least one:

Wherein, R is alkyl.

25. secondary cells as claimed in claim 24, it is characterised in that: described cation is at least one in 1-methyl isophthalic acid-propyl pyrrole alkane ion, 1-methyl isophthalic acid-butyl pyrrolidine ion, 1-methyl isophthalic acid-propylpiperdine ion and 1-methyl isophthalic acid-butyl piperidine ion.

26. secondary cells as claimed in claim 23, it is characterised in that: the removal lithium embedded current potential of the negative active core-shell material in described negative pole is not less than 0.25V (to Li/Li⁺)。

27. secondary cells as claimed in claim 26, it is characterised in that: described negative active core-shell material is silicon carbon material or aluminosilicate alloy material；The carbon comprised in described silicon carbon material is not graphite.

28. secondary cells as claimed in claim 27, it is characterised in that: described aluminosilicate alloy material is at least one in copper silicon sill and silicon tin-based material.

29. secondary cells as claimed in claim 26, it is characterised in that: described negative active core-shell material is titanium-based oxide.

30. secondary cells as claimed in claim 29, it is characterised in that: described titanium-based oxide is Li-Ti oxide.

31. secondary cells as claimed in claim 23, it is characterised in that: the content≤5ppm of halide ion in described electrolyte.

32. secondary cells as claimed in claim 24, it is characterised in that: described lithium salts in lithium hexafluoro phosphate, LiBF4, trifluoromethyl sulfonic acid lithium, lithium perchlorate, hexafluoroarsenate lithium, double (catechol) Lithium biborate, the dimalonic acid boric acid, di-oxalate lithium borate, three (catechol) lithium phosphate, three (perfluoro-ethyl) three lithium fluophosphate, trifluoromethyl sulfonic acid lithium, in double (trimethyl fluoride sulfonyl) imine lithium and double fluorine sulfimide lithium at least one.

33. secondary cells as claimed in claim 32, it is characterised in that: described lithium salts is selected from the first lithium salts at least one and the second lithium salts at least one；The first lithium salts described includes trifluoromethyl sulfonic acid lithium, double (trimethyl fluoride sulfonyl) imine lithium and double fluorine sulfimide lithium；Described the second lithium salts includes lithium hexafluoro phosphate and LiBF4.

34. secondary cells as claimed in claim 33, it is characterised in that: it is characterized in that: the quality of the first lithium salts described accounts for the 0.5～30% of described electrolyte gross mass；The quality of described the second lithium salts accounts for the 0.5～30% of described electrolyte gross mass.

35. secondary cells as claimed in claim 33, it is characterised in that: the first described lithium salts is 1:19～19:1 with the mol ratio of the second lithium salts.

36. secondary cells as claimed in claim 35, it is characterised in that: the first lithium salts described is 1:9～9:1 with the mol ratio of the second lithium salts.

37. secondary cells as claimed in claim 36, it is characterised in that: the first lithium salts described is 3:7～7:3 with the mol ratio of the second lithium salts.

38. secondary cells as claimed in claim 24, it is characterised in that: described basic components also includes organic solvent；Described organic solvent is at least one in carbonates, carboxylic acid esters, sulfurous esters, sulfonic acid esters, sulfone class, ethers, silicone, nitrile and fluoro phosphine nitrile.

39. secondary cells as claimed in claim 38, it is characterized in that: described organic solvent is methyl carbonic acid propylene, ethyl carbonate propylene, methyl carbonic acid phenol ester, ethylene carbonate, halogenated ethylene carbonate, Allyl carbonate, butylene, dimethyl carbonate, diethyl carbonate, Ethyl methyl carbonate, methyl propyl carbonate, vinylene carbonate, ethylene sulfite, propylene sulfite, butylene sulfite, dimethyl sulfite, sulfurous acid diethyl ester, dimethyl sulfoxide, second methyl sulfoxide, 1, 3-N-morpholinopropanesulfonic acid ester, 1, 4-butyl sultone, dioxolanes, dimethoxy propane, ethyoxyl five fluorine phosphine nitrile, phenoxy group five fluorine phosphine nitrile, in adiponitrile and succinonitrile at least one.

40. secondary cells as claimed in claim 24, it is characterised in that: described basic components also includes film former；Described film former is sulfur dioxide, ethylene sulfite (VS), vinylene carbonate (VC), sulfite, sulfoxide, sulphonic acid ester, halo organic ester, the unsaturated organic compound containing ethenylidene, organic boride, Li₂CO₃And in LiBOB at least one.

41. secondary cells as claimed in claim 24, it is characterised in that: described basic components also includes functional additive；Described functional additive is at least one in anti-overcharge additive, flame-retardant additive, conductive additive and extreme-pressure additive.

42. as described in claim 41 secondary cell, it is characterized in that: described functional additive be biphenyl (DP), cyclohexyl benzene, aromatic radical diamantane (obsolete), naphthalene derivatives, many polyphenyl, trimethyl phosphate (TMP), triphenyl phosphate (TPP), three (2,2,2 trifluoroethyls) phosphite ester, in phenodiazine (miscellaneous) benzene, three (five fluorinated phenyl) boron, ethyoxyl five fluorine phosphine nitrile, phenoxy group five fluorine phosphine nitrile, adiponitrile and succinonitrile at least one.

43. as described in claim 41 secondary cell, it is characterised in that: described basic components includes the ionic liquid of 70～100wt%, the organic solvent of 0～30wt%, the film former of 0～10wt%, the functional additive of 0～10wt%.

44. secondary cells as claimed in claim 23, it is characterised in that: the positive electrode active materials in described positive pole is selected from lithium nickel cobalt manganese oxide, lithium/nickel/cobalt composite oxide, lithium nickel cobalt aluminium composite oxide, li-mn-ni compound oxide, Lithium Phosphor Oxide, lithium and cobalt oxides and complex Li-Mn-oxide at least one.

45. secondary cells as claimed in claim 23, it is characterised in that: described barrier film is at least one in ethylene glycol terephthalate barrier film, polyacrylonitrile barrier film and Kynoar barrier film.

46. secondary cells as claimed in claim 23, it is characterised in that: the average pore size of described barrier film is 1～25 μm；The porosity of described barrier film is 50～85%.