SEPARATORS

The building blocks of a battery (e.g. LIB) are the cathode and anode, and these two electrodes are isolated by a separator. The separator is moistened with electrolyte and forms a catalyst that promotes the movement of ions from cathode to anode on charge and in reverse on discharge. Ions are atoms that have lost or gained electrons and have become electrically charged. Although ions pass freely between the electrodes, the separator is an isolator with no electrical conductivity.

The small amount of current that may pass through the separator is self-discharge and this is present in all batteries to varying degrees. Self-discharge eventually depletes the charge of a battery during prolonged storage.

Separators in most batteries are made of very simple plastic films that have the right pore size to allow ions to flow through while keeping the other components blocked. Battery separators need to have excellent porosity, as well as low cost, lightness and durability.

RotaLab supplies polypropylene (PP), polyethylene (PE), ceramic-embedded and other types of battery separators, which play the critical role of separating the cathode from the anode in lithium-ion (Li-ion) and lithium-air (Li-air) battery technologies.