ELECTRIC SEPARATOR COMPRISING A SHUT-DOWN MECHANISM, METHOD FOR THE PRODUCTION THEREOF AND ITS USE IN LITHIUM BATTERIES

摘要

The invention relates to electric separators for batteries, particularly lithium batteries, comprising a shut-down mechanism, and to a method for the production thereof. An electric separator is a separator, which is used in batteries and other devices, in which electrodes, e.g. while preserving ion conductivity, have to be separated from one another. Safety plays a very important roll in lithium batteries since, unlike other types of batteries (Pb, NiCd, NiMeH) that use water as a solvent for the electrolytes, lithium batteries use a combustible solvent such as organic carbonates. For this reason, it is absolutely necessary that a separator for lithium cells comprises an appropriate shut-down mechanism while, at the same time, not being permitted to melt down. To this end, an inventive electric separator is used that comprises a shut-down layer comprised of particles that melt at a desired temperature during which the pores of the separator close thereby stopping the ionic current. Due to the fact that the separator also comprises a porous inorganic (ceramic) layer on a support, the cells cannot melt through as a result of a completely melted separator.