The separator in a lithium-ion cell prevents physical contact between the anode and cathode while facilitating ion transport. The challenge in designing safe battery separators is the trade-off between mechanical robustness and porosity/transport properties.
Desired Characteristics of a Battery Separator One of the critical battery components for ensuring safety is the separator. Separators (shown in Figure 1) are thin porous membranes that physically separate the cathode and anode, while allowing ion transport.
The use of porous separators for flow batteries has already been put forward by the National Aeronautics and Space Administration (NASA) in the 1970s: “A further method to produce highly selective low resistance membranes is to use a porous plastic film as the substrate for a thin layer of ion exchange resin. …
When a lithium-ion cell shuts down, it instantly becomes the most resistive element in the circuit. The separator in the cell causes the voltage of the remaining cells in the battery to be dropped over it. R&D efforts are very active in the area of lithium-ion cell separators and their safety advances and opportunities.
The separator, a thin porous membrane that physically separates the anode and cathode in a lithium-ion cell, is one of the most critically important components to ensure cell safety. Its primary function is to prevent physical contact between the anode and cathode, while facilitating ion transport in the cell.
During the charging and discharging processes, ions, such as lithium ions in lithium-ion batteries, must migrate through the separator to maintain the electrochemical balance. The porous structure of the separator allows controlled ion flow while preventing electrode contact, which could lead to short circuits. 3. Electrical Insulation
OverviewHistoryMaterialsProductionPlacementEssential propertiesDefectsUse in Li-ion Batteries
Unlike many forms of technology, polymer separators were not developed specifically for batteries. They were instead spin-offs of existing technologies, which is why most are not optimized for the systems they are used in. Even though this may seem unfavorable, most polymer separators can be mass-produced at a low cost, because they are based on existing forms of technolo…