Various embodiments of solid-state conductors containing solid polymer electrolytes, electronic devices incorporating the solid-sate conductors, and associated methods of manufacturing are described herein. In one embodiment, a solid-state conductor includes poly(ethylene oxide) having molecules with a molecular weight of about 200 to about 8×106 gram/mol, and a soy protein product mixed with the poly(ethylene oxide), the soy protein product containing glycinin and beta-conglycinin and having a fine-stranded network structure. Individual molecules of the poly(ethylene oxide) are entangled in the fine-stranded network structure of the soy protein product, and the poly(ethylene oxide) is at least amorphous.