Gel electrolyte precursor compositions, electrochromic devices including gel electrolytes, and manufacturing methods thereof

1. A method of forming an electrochromic (EC) device, comprising:

forming a precursor composition comprising polyurethane acrylate oligomers and an ionically conducting phase, the precursor composition having a viscosity ranging from about 10,000 centipoise (cP) to about 80,000 cP;

forming a layer of the precursor composition on a first electrode disposed on a transparent substrate; and

curing the layer to form a gel electrolyte on the first electrode,

wherein the precursor composition comprises:

polymer network precursors comprising polyurethane acrylate oligomers; and

an ionically conducting phase.

2. The method of claim 1 , wherein the precursor composition further comprises: adhesion promoting monomers selected from isobornyl acrylate (IBOA), ethoxylated nonylphenol acrylate, poly(ethylene glycol) diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), trimethylolpropane triacrylate (TMPTA), ethoxyethoxyethyl acrylate, tripropylene glycol diacrylate (TPGDA), butyl acrylate (BA), hexanediol diacrylate (HDDA), or any combinations thereof.

3. The method of claim 2 , wherein:

the forming a precursor composition comprises crosslinking from about 10% to about 60% of the polymer network precursors, prior to forming the layer, such that the precursor composition has a viscosity ranging from about 25,000 cP to about 80,000 cP;

the precursor composition comprises from about 20 wt % to about 90 wt % of the polymer network precursors, based on the total weight of the precursor composition;

the ionically conducting phase comprises an electrolyte salt, a plasticizer comprising an ionic liquid selected from N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide (Py14TFSI), imidazolium bis(trifluoromethylsulfonyl)imide ([Im][TFSI]), butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide, n-ethyl-N,N-dimethyl-2-methoxyethylammonium bis(trifluoromethylsulfonyl)imide, 1-(3-methoxypropyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide, N-(3-hydroxypropyl)pyridinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, trihexyltetradecylphosphonium tris(pentafluoroethyl)trifluorophosphate, N-methoxyethyl-N-methylmorpholinium bis(trifluoromethylsulfonyl)imide, or any combinations thereof, and a solvent selected from tetraglyme, propylene carbonate, sulfolane or any combinations thereof; and

the precursor composition further comprises an initiator selected from 2,2-Dimethoxy-2-phenylacetophenone, phenylphosphineoxide, benzoyl peroxide, or any combinations thereof.

4. The method of claim 1 , wherein the method further comprises adding to the precursor composition, based on the total weight of the precursor composition, from about 0.1 wt % to about 3 wt % of a metal oxide powder thickener, prior to forming the layer.

5. The method of claim 1 , wherein the method further comprises laminating the first substrate to a second substrate comprising a second electrode, such that the gel electrolyte contacts the first and second electrodes, to form the EC device.

6. The method of claim 1 , wherein:

the method further comprises:

connecting the first substrate to a second substrate comprising a second electrode; and

applying a sealant to the first and second substrates, such that a fluid-retaining space is formed between the first and second substrates; and

the forming a layer of the precursor composition comprises injecting the precursor composition into the space, such that the precursor composition contacts the first and second electrodes.

7. The method of claim 1 , wherein the curing comprises heating the layer or applying ultraviolet light to the layer.