Elastic and stretchable gel polymer electrolyte and methods of making the same

A method of making a coated electrode for use in preparation of a lithium ion battery comprising:

• (i) combining an electrode active material, a binder composition, and a conductive agent to form a slurry;
• (ii) applying the slurry to a current collector to form a coated current collector comprising a slurry layer on the current collector;
• (iii) drying the slurry layer on the coated current collector to form a film on the current collector, wherein the electrode comprises the film and the current collector;
• (iv) applying a polymer coating composition in a solvent to the electrode to form a coated electrode having an outer surface substantially covered by the polymer coating composition, wherein the polymer coating composition is solution-coated on the electrode;
• and
• (v) evaporating the solvent from the polymer coating composition to form a polyurethane gel polymer electrolyte coating on the electrode,
• wherein the polyurethane gel polymer electrolyte comprises a polyurethane formed by a reaction comprising (i) an isocyanate and (ii) a polyol, wherein a molar ratio of the polyol to the isocyanate is in a range of from about 1.0:1.2 to about 1.0:2.0;
• wherein the isocyanate is an aromatic diisocyanate and the polyol is a polyether polyol;
• wherein the solvent is selected from the group consisting of N, N-dimethylacetamide (DMAc), tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), tetramethylsilane (TMS), and dimethylformamide (DMF).