CN1091306C

CN1091306C - Solid electrolyte and preparation and uses thereof

Info

Publication number: CN1091306C
Application number: CN98100827A
Authority: CN
Inventors: 胡树文; 方世璧; 李永军
Original assignee: Institute of Chemistry CAS
Current assignee: Institute of Chemistry CAS
Priority date: 1998-02-18
Filing date: 1998-02-18
Publication date: 2002-09-18
Anticipated expiration: 2018-02-18
Also published as: CN1193821A

Abstract

The present invention relates to a solid electrolyte which is a composite system composed of an inorganic electrolyte and an organic polyelectrolyte. Interaction between the organic electrolyte and the inorganic electrolyte is utilized to make the ionic conductance as high as 10<-3>S/cm. The addition of the organic polyelectrolyte greatly enhances the machinability of the system. The solid electrolyte can be used in the fields of secondary lithium ion batteries, electrochromic devices, sensors, etc.

Description

A kind of solid electrolyte and its production and use

Technical field:

The present invention relates to a kind of novel solid electrolyte and its production and use, this electrolyte has ionic conductance height, good, safe, the leak free advantage of machining property.At lithium rechargeable battery, aspects such as electrochromic device and transducer are expected to replace traditional liquid electrolyte, are with a wide range of applications.

Background technology:

Solid electrolyte is the general name of ionic conductivity solid, it have safe in utilization, do not have to leak, pollution-free, advantage such as self discharge is few and the life-span is long.In energy problem serious day by day today, it has more and more caused people's extensive interest.Discover that the composite inorganic electrolyte has higher ionic conductance, as AlCL ₃-LiClO ₄The room-temperature ion conductivity of compound system reaches 10 ^-2.3S/cm.Research also shows, the compound crystalline structure that can destroy single inorganic salts of inorganic salts reduces the electrolytical fusing point of inorganic salts, make inorganic cation easier can break away from anionic constraint and freely the motion [see C.A.Angell, nature, 362,137-139 (1993)].But its machining property is poor, and film forming is poor, thereby has limited its application in practice greatly.

The solid organic polymer electrolyte is a kind of novel solid electrolyte that just grows up in recent ten years.This family macromolecule is to be matrix with the polyethers macromolecular material, and alkali metal ion is a carrier ion.It is except the performance with general solid electrolyte, and also have outstanding feature: plasticity is strong.These characteristics have been brought two big benefits: easily process film forming, the internal resistance of cell reduces; With contacting of electrode, the electric current that discharges and recharges with increase.Yet, copolymer solid electrolyte also exists fatal shortcoming: ionic conductance is lower than the level of practical application, its main cause is along with the inorganic salt content in the polymer dielectric increases, the inorganic ions that dissociates has taken place to gather, make the effective-current subnumber descend, ionic conductance reduces [seeing United States Patent (USP) 4882243] greatly.The highest room-temperature ion conductivity of report also only reaches 10 at present ^-4S/cm, thus limited its application in practice greatly.

Summary of the invention:

The objective of the invention is to overcome inorganic molten salt electrolyte machining property difference and the low shortcoming of polyelectrolyte intermediate ion conductivity, and the machining property that provides high ionic conductance to become reconciled.

The present invention proposes the novel solid electrolyte, the compound system of forming by " organic bath (organic salt)-inorganic electrolyte (inorganic salts) ": the organic salt that has polar group that has synthesized several different structures, then that organic salt and inorganic salts is compound, inorganic salts and the electrolytical advantages of organic polymer are got up, utilize the interaction of organic salt and inorganic salts on the one hand, further destroy the crystal phase structure of inorganic salts, impel dissociating of inorganic salts, make its ionic conductance up to 10 ^-3S/cm; On the other hand, owing to used organic salt, the skeleton of organic molecule can play a part improvement system machining property simultaneously.

Solid electrolyte of the present invention (percentage by weight) composed of the following components: component 1: inorganic salts; Content: 20-90% component 2: organic salt; Content: 10-80%

Said components 1 comprises: LiClO ₄, LiClO ₃, LiNO ₃, LiOAC, LiI, Li ₂CO ₃, Li ₂SO ₄, LiCl, LiBr, LiCF ₃SO ₃

Said components 2 comprises synthetic several sulfate that have polar group, sulfonate, and carbonate and quaternary ammonium salt, for example: (low) polyoxyethylene thiazolinyl lithium sulfate (PEGSO ₄Li), (low) polyoxyethylene thiazolinyl sulfonic acid lithium (PEGSO ₃Li), the propionic acid lithium, lithium dodecyl sulfate, nonyl phenol (low) polyoxyethylene thiazolinyl lithium sulfate, nonyl phenol (low) polyoxyethylene thiazolinyl lithium sulfate, polystyrolsulfon acid lithium, the polyvinyl alcohol lithium sulfate, polymethyl siloxane propyl group oligomerisation oxyethylene group lithium sulfate (PMSPSLi), polymethyl acid oligomer ethylene oxide is the sulfonic acid lithium, polymethyl acid oligomer ethylene oxide tetramethyl ammonium chloride.

The electrolytical preparation process of " organic salt-inorganic salts " of the present invention compound system step is in the following order carried out:

1 drying and dehydrating: the inorganic salts of SILVER REAGENT such as LiClO ₃And Li ₂SO ₄In vacuum drying oven one by one by 40 ℃, 60 ℃, 80 ℃, 100 ℃, 120 ℃ intensification drying and dehydratings, until sample no longer till the weightlessness.

2 organic salts-inorganic salt system compound: the inorganic salts such as the LiClO that will account for 20%-90% ₃The organic salt that accounts for 10-80% such as the PEGSO that cross with drying ₄Li, PEGSO ₃Li or PMSPSLi heating and melting, after in drying box, fully mixing, be transferred in the vacuum drying oven 120 ℃ dry down,, sample is placed in the drier cools off at last no longer till the weightlessness up to sample.

The solid electrolyte of the present invention preparation has been obtained following invention effect: the interaction that (1) makes full use of organic salt and inorganic salts has improved the room-temperature ion conductivity of solid electrolyte, has reached the peak of present non-aqueous system report, sees Table one; (2) the organic molecule skeleton has improved its machining property.This invention can be used in fields such as lithium rechargeable battery, electrochromic device and transducer.

The room-temperature ion conductivity (conductivity) of the different systems of table one and form concern LiClO ₃Content 0% 10% 20% 40% 60% 80% 100

Electricity 1.6 * 3.1 * 1.4 * 1.2 * 1.5 * 8.6 * 1.7 * conductance (S/cm) 10 of % embodiment one ^-510 ^-510 ^-710 ^-610 ^-510 ^-410 ^-4Electricity 2.4 * 3.2 * 2.1 * 1.5 * 2.2 * 5.9 * 1.7 * conductance (S/cm) 10 of embodiment two ^-510 ^-510 ^-710 ^-610 ^-510 ^-410 ^-4Electricity 1.6 * 2.5 * 3.9 * 2.5 * 3.5 * 1.05 * 1.7 * conductance (S/cm) 10 of embodiment three ^-510 ^-510 ^-710 ^-610 ^-510 ^-310 ^-4Electricity 1.7 *-4.8 * 8.5 * 1.9 * 7.9 * 1.7 * conductance (S/cm) 10 of comparative example one ^-710 ^-610 ^-510 ^-410 ^-410 ^-4Electricity 5.01 * 3.16 * 1.25 * 1.61 * 6.3 * 1.58 * 1.7 * conductance (S/cm) 10 of comparative example two ^-610 ^-510 ^-510 ^-710 ^-610 ^-510 ^-4

Embodiment:

Embodiment one

LiClO ₃-PEGSO ₄Li: the organic salt PEGSO that selects to have high polar group ₄Li and inorganic salts LiClO ₃Compound, the room-temperature ion conductivity of finding system is along with LiClO ₃The increase of content increases afterwards earlier and falls, and at LiClO ₃Content is to reach maximum 8.6 * 10 at 80% o'clock ^-4S/cm has reached practical level.

Embodiment two

LiClO ₃-PEGSO ₃Li: with organic salt PEGSO ₃Li and inorganic salts LiClO ₃Compound, the room-temperature ion conductivity of finding system is also at LiClO ₃Content is to reach maximum 5.9 * 10 at 80% o'clock ^-4S/cm, but be lower than LiClO ₃-PEGSO ₃The ionic conductance of system.

Embodiment three

PMSPSLi-LiClO ₃: the methylsiloxane propyl group oligomerisation ethylene oxide lithium sulfate (PMSPSLi) and the LiClO that will have flexible chain ₃After compound, its room-temperature ion conductivity is at LiClO ₃Content be to reach maximum 1.05 * 10 at 80% o'clock ^-3S/cm, this ionic conductance also are the peaks of non-aqueous system electrolyte report, and contain 20% organic polymer, have reached practical level.Comparative example one

As a comparison, with LiClO ₃And Li ₂SO ₄Carry out compoundly with different ratios, can find, along with LiClO ₃Adding, the room-temperature ion conductivity of compound system increases gradually, and at LiClO ₃Content is to reach maximum at 80% o'clock.The result shows that compound the dissociating of impelling inorganic salts of inorganic salts improved its effective-current subnumber, so its room-temperature ion conductivity increases along with the adding of second component, and has reached maximum within the specific limits.Comparative example two

PEO600-LiClO ₃: as a comparison, with PEO600 and LiClO ₃Compound, as can be seen, PEO600-LiClO ₃The ionic conductance of system is far below PEGSO ₄Li-LiClO ₃The level of compound system.This has illustrated that effectively simple organic substance does not have the effect that destroys the inorganic salts crystallization, and organic salt can play destruction inorganic salts crystalline structure, the effect that impels inorganic salts to dissociate.

Claims

1 one kinds of solid electrolytes is characterized in that the compound system that described solid electrolyte is made up of inorganic electrolyte and organic bath, and its component and content are as follows by weight percentage:

Inorganic salts: 20%-90%, organic salt: 10%-80%,

Above-mentioned inorganic salts are lithium perchlorate, lithium chlorate, lithium nitrate, lithium acetate, lithium iodide, lithium carbonate, lithium sulfate, lithium chloride, lithium bromide, trifluoromethyl sulfonic acid lithium, above-mentioned organic salt is oligomeric oxyethylene group lithium sulfate, oligomeric oxyethylene group sulfonic acid lithium, the propionic acid lithium, lithium dodecyl sulfate, the oligomeric oxyethylene group lithium sulfate of nonyl phenol, the oligomeric oxyethylene group lithium sulfate of nonyl phenol, the polystyrolsulfon acid lithium, the polyvinyl alcohol lithium sulfate, polymethyl siloxane propyl group oligomerisation oxyethylene group lithium sulfate, polymethyl acid oligomer ethylene oxide is the sulfonic acid lithium, polymethyl acid oligomer ethylene oxide tetramethyl ammonium chloride.

2 a kind of method for preparing solid electrolyte according to claim 1 is characterized in that step is carried out in the following order:

(1) drying and dehydrating: the inorganic salts lithium chlorate of SILVER REAGENT or lithium sulfate in vacuum drying oven one by one by 40 ℃, 60 ℃, 80 ℃, 100 ℃, 120 ℃ intensification drying and dehydratings;

(2) organic salt-inorganic salt system is compound: with the inorganic salts lithium chlorate of 20-90% and the oligomeric oxyethylene group lithium sulfate of 10-80%, oligomeric oxyethylene group sulfonic acid lithium or polymethyl siloxane propyl group oligomerisation oxyethylene group lithium sulfate heating and melting, after in drying box, fully mixing, be transferred in the vacuum drying oven dry down at 120 ℃.

The purposes of 3 a kind of solid electrolytes according to claim 1 is characterized in that being applied in lithium rechargeable battery, electrochromic device or sensor field.