A novel small-molecule compound of lithium iodine and 3-hydroxypropionitrile (HPN) has been successfully synthesized. Our combined experimental and theoretical studies indicated that LiIHPN is a Li-ion conductor, which is utterly different from the I--anion conductor of LiI(HPN)(2) reported previously. Solid-state lithium-air batteries based on LiIHPN as the electrolyte exhibit a reversible discharge capacity of more than 2100 mAh g(-1) with a cyclic performance over 10 cycles. Our findings provide a new way to design solid-state electrolytes toward high-performance lithium-air batteries.