As we know, each lithium battery is composed of four essential parts: the anode and cathode, the electrodes that bookend each lithium-ion cell, a liquid electrolyte, and a separator.

While the cathode and anode determine the basic performance of a battery, electrolyte and separator determine the safety of a battery, the functions as a physical barrier keeping cathode and anode apart. It prevents the direct flow of electrons and carefully lets only the ions pass through the internal microscopic hole.

● Widest of all the three materials, winded (cylindrical and prismatic cells) or stacked (pouch cell) inside a Lithium-ion cell, meaning its width is more than the width of the cathode and the anode of the cell.

Separators are made up of polyolefin material, which is either polypropylene or polyethylene or both combined. These materials have very good chemical and mechanical stability and are cost-effective.

● LFP chemistry cells, most of the time, use a single-layer PP dry separator. It is the cheapest type of separator out there.

● NMC and NCA chemistry cells tend to use different types of separators in the range of coated separators and wet separators.

● Tri-layer separator made up of PP/PE/PP is very popular because, in case of high temperatures being reached inside the cell, the middle layer of PE melts and shuts down the cell operation without losing mechanical integrity. It is possible because the melting point of PE (around 130C) is lesser than PP(around 160°C).

In a solid-state battery, the solid electrolyte placed between the electrodes eliminates the use of a separator.