An autonomous battery shutdown system includes a battery including an anode and a cathode, and an electrolyte composition between the anode and the cathode. The electrolyte composition includes an ionically conductive liquid containing lithium ions, and temperature-sensitive particles including a polymer having a melting temperature between 60.degree. C. and 120.degree. C. When the temperature of the battery exceeds 120.degree. C., the temperature-sensitive particles form an ion barrier that traverses the battery. The resulting shutdown battery may have a specific charge capacity that is more than 98% lower than the specific charge capacity of the original battery.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under contract number(s) DE-AC0206CH11357, ANL 9F 31921, and 392 NSF CHE 09-36888 FLLW ARRA, awarded by the Department of Energy and the National Science Foundation ACC Fellowship. The government has certain rights in the invention.