Low-temperature solid polymer electrolyte for electrochromic device

Abstract

The invention discloses a low-temperature solid polymer electrolyte for an electrochromic device. The solid polymer electrolyte may include one or more ionic liquids, one or more polymers, and one or more electrolyte salts, one or more curing agents, one or more solvents. The processing mode of the solid polymer electrolyte is that the solid polymer electrolyte is formed by a method of heating curing or UV curing after slit coating, the solid polymer electrolyte can still keep an ion transmission function in an environment of-20 DEG C, and when the solid polymer electrolyte is applied to an electrochromic device, the electrochromic device can still keep normal operation at a low temperature.

Description

Technical Field

[0001] The invention relates to a low-temperature solid polymer electrolyte for an electrochromic device, belonging to the technical field of organic solid polymer electrolytes. Background Art

[0002] Electrochromic devices are electrochromic materials that undergo reversible color changes by applying voltage. Electrochromic technology can be applied to car sunroofs to provide sunshade and heat insulation. The electrolyte layer plays a key role in ion transport in electrochromic devices.

[0003] The rate of ion transmission is closely related to temperature. Ions are difficult to move at low temperatures. For example, the patent 201780005574.X previously applied by the applicant solves several technical problems and defects in existing electrochromic devices and the solid electrolytes used, but still fails to solve the problem that electrochromic devices and the solid electrolytes used are difficult to operate at low temperatures. At present, solid electrolytes that can still transmit ions below zero degrees are still a huge challenge. The inability to operate normally at low temperatures greatly limits the application of electrochromic in automotive skylights. Summary of the invention

[0004] The purpose of the present invention is to solve the problem that the electrochromic device can hardly operate at low temperatures. The present invention aims to provide a low-temperature solid polymer electrolyte so that the electrochromic device can still operate normally at low temperatures.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] In one aspect of the present invention, there is provided a low-temperature solid polymer electrolyte comprising:

[0007] one or more ionic liquids;

[0008] one or more polymers;

[0009] one or more electrolyte salts;

[0010] one or more curing agents; and

[0011] One or more than one solvent.

[0012] Preferably, the ionic liquid comprises one or more than one of pyridine, pyrrole, imidazole and piperidine ionic liquids;

[0013] and / or, the electrolyte salt comprises one or more than one metal salt;

[0014] And / or, the curing agent includes one or more than one of an amine curing agent, an acid anhydride curing agent and a thiol curing agent.

[0015] Preferably, the polymer comprises one or more than one of polymethacrylate (PMMA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide, polyethylene glycol diglycidyl ether, polyethylene glycol diacrylate, and polyethylene terephthalate.

[0016] Preferably, the ionic liquid comprises one or more of N-methyl-N-ethylpyrrolidine bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidine bis(trifluoromethanesulfonyl)imide, 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-vinyl-3-butylimidazolium bis(trifluoromethylsulfonyl)imide, N-hexyl-4-methylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-butylpyridine trifluoromethanesulfonate, and N-hexyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide.

[0017] Preferably, the metal salt is a metal lithium salt.

[0018] Preferably, the metal lithium salt is selected from one or more of LiBOB, LiFSI, LiTFSI, LiPF6, LiBF4, LiClO4 and LiCF3SO3.

[0019] Preferably, the amine curing agent includes one or more than one of polyamide, triethylenetetramine, tetraethylenepentamine, and meta-xylylenediamine;

[0020] And / or, the acid anhydride curing agent includes one or more of phthalic anhydride, methylcyclohexene tetracarboxylic dianhydride and methylcyclohexene tetracarboxylic dianhydride;

[0021] And / or, the thiol curing agent includes one or more of ethylene glycol dimercaptoacetate, 1,4-butanediol di(3-mercaptopropionate), and trimethylolpropane tris(3-mercaptopropionate).

[0022] Preferably, the solvent has a boiling point above 60°C.

[0023] Preferably, the solvent comprises one or more than one of isopropyl alcohol, sec-butyl alcohol, butanone, propylene glycol methyl ether acetate, propylene carbonate, and diethyl carbonate.

[0024] Preferably, the low-temperature solid polymer electrolyte has a transparency of more than 80%.

[0025] Another aspect of the present invention provides the use of the aforementioned low-temperature solid polymer electrolyte in an electrochromic device.

[0026] Another aspect of the present invention provides an electrochromic device, comprising:

[0027] a first electrode;

[0028] a second electrode;

[0029] an electrochromic material deposited on at least the first electrode; and a low temperature solid polymer electrolyte disposed between the electrochromic material and the second electrode; wherein,

[0030] The low-temperature solid polymer electrolyte is the low-temperature solid polymer electrolyte described above.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The low-temperature solid polymer electrolyte provided by the present invention has sufficient mechanical strength and arbitrary shape, and can be formed into thin films and products in thin film shapes; compared with conventional polymer electrolytes, the present invention introduces ionic liquids and can exhibit better ionic conductivity at low temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 1 is a dark-to-bright-state transmittance-time curve of a 500 mm*500 mm electrochromic device including a low-temperature solid polymer electrolyte at -5°C, -9°C, -12.9°C, and -20°C according to an exemplary embodiment.

[0034] Figure 2 It is the transmittance-time curve from light state to dark state of 500mm*500mm electrochromic device at -5℃, -9℃, -12.9℃, and -20℃. DETAILED DESCRIPTION

[0035] For ease of understanding, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] One aspect of the present invention relates to a solid polymer electrolyte. In some embodiments, the solid polymer electrolyte may include one or more ionic liquids, one or more polymers and one or more electrolyte salts, one or more curing agents, and one or more solvents.

[0037] Another aspect of the present invention relates to an electrochromic device. In some embodiments, the electrochromic device includes a first electrode, a second electrode, a charge storage layer and an electrochromic material deposited on the electrodes, respectively, and a solid polymer electrolyte disposed therein. The solid polymer electrolyte may include one or more ionic liquids, one or more polymers and one or more electrolyte salts, one or more curing agents, and one or more solvents.

[0038] The term ionic liquid refers to room temperature ionic liquids, room temperature molten salts or organic ionic liquids, etc., which are composed of organic cations and inorganic or organic anions.

[0039] The one or more ionic liquids of the present invention may include one or more pyridines, pyrroles, imidazoles, and piperidines. Suitable ionic liquids may include, but are not limited to, N-methyl-N-ethylpyrrolidine bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidine bis(trifluoromethanesulfonyl)imide, 1-allyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-vinyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide, N-hexyl-4-methylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-butylpyridine trifluoromethanesulfonate, N-hexyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide, combinations thereof, and the like. In some embodiments, the total amount of the ionic liquid may be from 2 wt % to about 20 wt % based on the total weight of the solid polymer electrolyte.

[0040] One or more than one polymer of the present invention may include one or more than one of C, N, O, H, F, etc. Suitable polymers may include, but are not limited to, polymethacrylate (PMMA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide, polyethylene glycol diglycidyl ether, polyethylene glycol diacrylate, polyethylene terephthalate, combinations thereof, etc. In embodiments where there are multiple polymers, the polymer may be cross-linked to form a network with enhanced mechanical properties. In some embodiments, the total amount of polymer may be from about 0 wt % to about 20 wt %, based on the gross weight of the solid polymer electrolyte.

[0041] One or more than one electrolyte salt of the present invention may include one or more than one metal salt. Suitable electrolyte salts may include organic lithium salts and inorganic lithium salts, including but not limited to LiBOB (lithium bis(oxalate)borate), LiFSI (lithium bis(fluorosulfonyl)imide), LiTFSI (lithium bis(trifluoromethylsulfonyl)imide), LiPF6, LiBF4, LiClO4, LiCF3SO3, combinations thereof, etc. In some embodiments, the total amount of electrolyte salts may be from about 10 wt % to about 40 wt %, based on the total weight of the solid polymer electrolyte.

[0042] The one or more curing agents of the present invention may include, but are not limited to, polyamide, triethylenetetramine, tetraethylenepentamine, m-xylylenediamine, trimethylolpropane tris(3-mercaptopropionate), phthalic anhydride, methylcyclohexene tetracarboxylic dianhydride, methylcyclohexene tetracarboxylic dianhydride, combinations thereof, etc. In some embodiments, the total amount of curing agent may be about 2 wt % to about 15 wt % based on the total weight of the solid polymer electrolyte.

[0043] The one or more than one solvent of the present invention may include, but is not limited to, isopropyl alcohol, sec-butyl alcohol, butanone, propylene glycol methyl ether acetate, propylene carbonate, diethyl carbonate, combinations thereof, etc. In some embodiments, the total amount of solvent may be from about 0 wt % to about 70 wt % based on the total weight of the solid polymer electrolyte.

[0044] The solid polymer electrolyte of the present invention is coated on a substrate by slit coating, and after the solvent is dried, heat curing or UV curing is performed in an oven to form a solid polymer electrolyte.

[0045] The electrochromic device of the present invention comprises a first electrode, a second electrode, a charge storage layer and an electrochromic material respectively deposited on the electrodes, and a solid polymer electrolyte disposed therein. The materials used for the first and second electrodes may include, but are not limited to, tin-doped indium oxide (ITO), fluorine-doped indium oxide, zinc-doped indium oxide, silver nanowires, carbon nanotube films, patterned metals on glass or plastic substrates, combinations thereof and / or other such transparent materials exhibiting sufficient electrical conductivity. The charge storage layer material deposited on the first electrode may include metal oxides such as MoO3, V2O5, Nb2O5, WO3, TiO2, Ir(OH) x , SrTiO3, ZrO2, La2O3, CaTiO3, sodium titanate, potassium niobate, combinations thereof, etc. The electrochromic material on the second electrode may include a conductive polymer, such as poly-3,4-ethylenedioxythiophene (PEDOT), poly-2,2'-bithiophene, polypyrrole, polyaniline (PANI), polythiophene, polyisothiophene, poly-o-aminophenol, polypyridine, polyindole, polycarbazole, polyquinone, octacyanophthalocyanine, combinations thereof, etc.

[0046] Example

[0047] 0.8g of PVDF polymer is combined with a certain amount (e.g., 5g, 10g, or 15g) of PEO oligomer, dissolved in 20g or 30g of butanone, and 5g, 10g, or 15g of ionic liquid N-methyl-N-ethylpyrrolidine bistrifluoromethylsulfonyl imide salt is added. 10g, 12g, or 15g of LiTFSI is dissolved in 8g, 10g, or 12g of butanone and added to the above mixture. 5g or 10g of polyamide is added to the solution and stirred evenly. It is deposited on the charge storage layer by, for example, slit extrusion coating or spin coating. After the solvent is dried, it is heated at 110°C in an oven for 10min. After complete curing, it is pressed together with the electrochromic layer to obtain an electrochromic film, which can be used to assemble an electrochromic device.

[0048] in, Figure 1 A dark-to-light-state transmittance-time curve of a 500 mm*500 mm electrochromic device including a low-temperature solid polymer electrolyte at -5°C, -9°C, -12.9°C, and -20°C is provided in accordance with an exemplary embodiment.

[0049] Figure 2 Provided is a light-to-dark-state transmittance-time curve of a 500 mm*500 mm electrochromic device assembled in an exemplary embodiment at -5°C, -9°C, -12.9°C, and -20°C.

[0050] Depend on Figure 1 and Figure 2 The results show that the low-temperature solid polymer electrolyte provided by the present invention is used in an electrochromic device, so that the electrochromic device can still operate normally at low temperatures.

[0051] Application / Use

[0052] Embodiments of the low temperature solid polymer electrolytes disclosed herein can be used in a variety of applications, devices, industries, etc. A particular application of the solid polymer electrolytes disclosed herein relates to use in electrochromic devices. Electrochromic devices are often associated with smart window and display technologies, such as anti-glare automotive mirrors; smart windows configured for use in automobiles, aircraft, buildings, etc. that adjust transmission or reflection of solar radiation; protective eyewear; camouflage and / or color-changing materials; and the like.

[0053] The above description is only a preferred embodiment of the present invention and is not any formal or substantial limitation of the present invention. It should be pointed out that a person skilled in the art can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A low-temperature solid polymer electrolyte, characterized in that: It contains: one or more ionic liquids; one or more polymers; one or more electrolyte salts; one or more curing agents; and One or more than one solvent.

2. The low-temperature solid polymer electrolyte according to claim 1, characterized in that: The ionic liquid includes one or more than one of pyridine, pyrrole, imidazole and piperidine ionic liquids; and / or, the electrolyte salt comprises one or more than one metal salt; And / or, the curing agent includes one or more than one of an amine curing agent, an acid anhydride curing agent and a thiol curing agent.

3. The low-temperature solid polymer electrolyte according to claim 1, characterized in that: The polymer includes one or more than one of polymethacrylate (PMMA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyethylene oxide, polyethylene glycol diglycidyl ether, polyethylene glycol diacrylate, and polyethylene terephthalate.

4. The low-temperature solid polymer electrolyte according to claim 2, characterized in that: The ionic liquid includes one or more of N-methyl-N-ethylpyrrolidine bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidine bis(trifluoromethanesulfonyl)imide, 1-allyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-vinyl-3-butylimidazolium bis(trifluoromethanesulfonyl)imide, N-hexyl-4-methylpyridine bis(trifluoromethanesulfonyl)imide, N-ethylpyridine bis(trifluoromethanesulfonyl)imide, N-butylpyridine trifluoromethanesulfonate, and N-hexyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide.

5. The low-temperature solid polymer electrolyte according to claim 2, characterized in that: The metal salt is a metal lithium salt.

6. The low-temperature solid polymer electrolyte according to claim 5, characterized in that: The metal lithium salt is selected from one or more of LiBOB, LiFSI, LiTFSI, LiPF6, LiBF4, LiClO4 and LiCF3SO3.

7. The low-temperature solid polymer electrolyte according to claim 2, characterized in that: The amine curing agent includes one or more than one of polyamide, triethylenetetramine, tetraethylenepentamine, and meta-xylylenediamine; And / or, the acid anhydride curing agent includes one or more of phthalic anhydride, methylcyclohexene tetracarboxylic dianhydride and methylcyclohexene tetracarboxylic dianhydride; And / or, the thiol curing agent includes one or more of ethylene glycol dimercaptoacetate, 1,4-butanediol di(3-mercaptopropionate), and trimethylolpropane tris(3-mercaptopropionate).

8. The low-temperature solid polymer electrolyte according to claim 1, characterized in that: The solvent has a boiling point above 60°C.

9. The low-temperature solid polymer electrolyte according to claim 8, characterized in that: The solvent includes one or more than one of isopropyl alcohol, sec-butyl alcohol, butanone, propylene glycol methyl ether acetate, propylene carbonate, and diethyl carbonate.

10. The low-temperature solid polymer electrolyte according to claim 1, characterized in that: The low-temperature solid polymer electrolyte has a transparency of more than 80%.

11. Use of the low-temperature solid polymer electrolyte according to any one of claims 1 to 10 in an electrochromic device.

12. An electrochromic device, characterized in that: It includes: a first electrode; a second electrode; an electrochromic material deposited on at least the first electrode; and a low temperature solid polymer electrolyte disposed between the electrochromic material and the second electrode; wherein, The low-temperature solid polymer electrolyte is the low-temperature solid polymer electrolyte according to any one of claims 1 to 10.

Images