NOVELTY - Branched rod-coil polyimide-poly(alkylene oxide)copolymers (I) cured at ambient temperatures and derived from the reaction of primary amine-terminated poly(alkylene oxide) oligomers and dianhydrides in solution to form linear amine terminated polyamic-acid prepolymers, imidizing the polyamic-acid prepolymers in the solution, and subsequently adding to the polyimide solution trifunctional compounds forming solid polyimide-poly(alkylene oxide)copolymers, is claimed.    USE - (I) are useful to prepare polymeric electrolytes, which are useful in batteries for aerospace applications.    ADVANTAGE - (I) is capable of holding large volumes of liquid while maintaining good dimensional stability. The films obtained by (I) hold over four times their weight at room temperature of liquids such as ionic liquids and/or carbonate solvents. The coil segments of (I) allow the copolymer to hold solvents at high temperatures. (I) offers the flexibility of making a highly conductive electrolyte with either no volatile components of ionic liquid being added, or with the addition of solvent, which increases the battery safety and provides high lithium ion conductivity at ambient to high temperatures. (I) is environmental friendly and is inexpensive. The process provides a polymer gel electrolyte that is easy to fabricate with good dimensional stability, where the process is very versatile; and the imide segments still provide mechanical strength, phase separation, and a completely amorphous polymer in the presence of lithium salts. (I) increases the battery life cycle.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) preparing branched rod-coil polyimide-poly(alkylene oxide)copolymer electrolyte gel comprising reacting stoichiometric amounts of a primary amine-terminated poly(alkylene oxide) oligomer and dianhydrides in an organic solution at ambient temperatures to form amine-terminated polyamic-acid prepolymers, imidizing the polyamic-acid prepolymers in solution at increased temperatures, and subsequently adding to the amine-terminated polyimide solution trifunctional compounds forming solid polyimide-poly(alkylene oxide) copolymers; and    (2) preparing branched rod-coil polyimide poly(alkylene oxide)copolymers electrolytes comprising reacting stoichiometric amounts of primary amine-terminated poly (alkylene oxide) oligomers and dianhydrides in an organic solvent forming an organic solution at ambient temperatures to obtain amine-terminated polyamic-acid prepolymers, imidizing the polyamic-acid prepolymers in the solution at increased temperatures, and subsequently adding to the polyimide solution trifunctional compounds, lithium salts, ionic liquids, and alumina forming solid polyimide-poly(alkylene oxide)copolymer electrolytes.