New Ceramic Separator by Porous Power Increases Reliability and Safety of Lithium-ion Batteries

Lithium-ion batteries have many applications, but in today's society mobile devices have become synonymous with these batteries. A new generation of lithium-ion batteries along with improved hardware and software has made it possible to use our mobile devices longer before we need to plug-in to recharge. Although the battery technology is very crucial, the only time we hear about lithium-ion batteries is when they malfunction. Boeing's new Dreamliner 787 airplane was a recent example of overheating lithium-ion batteries that grounded the planes before the issue was resolved.

Porous Power, a manufacturer of separator membranes that improve the safety, cycle life and performance of lithium-ion batteries, has introduced a new type of ceramic separator designed to increase these features for lithium-ion batteries.

As the market for lithium batteries continues to increase year over year, increasing their performance and safety is one of the biggest issues hardware manufacturers face.

Porous Power Technologies was formed in 2006 by developing a new micro-porous membrane material designed specifically for use as a lithium-ion battery separator. The company developed a propriety polyvinylidene fluoride (PVDF) technology for commer­cialization and introduced a new level of safety and reliability to the industry.

The development of the new SYMMETRIX NC2020, was created in partnership with Ahlstrom, a high performance fiber-based materials company, to deliver improvements in all three key areas: safety, cycle life and performance, but especially safety.

The new separators are manufactured by blending SYMMETRIX NC2020’s ceramic particles with PVDF polymer to form a flexible, ceramic-rich microporous membrane. This allows ions to flow freely through the open pore structure providing cells reliable power across a range of temperature fluctuations.

Additional benefits of SYMMETRIX NC2020 lithium-ion battery separators include:

• More power in high-current applications, greater specific energy at higher rates, extended cycle life and long storage life/low self-discharge rates
• Reduced battery separator shrinkage
• Improved puncture and abuse resistance
• Increased stability during high-voltage operation
• Faster, cooler cell charge/discharge with less degradation of battery performance
• Good high and low temperature functionality and higher bake-out and operating temperatures
• Stable, benign degradation/decomposition under various abuse conditions

"Use of ceramics in separators is not new. However, most manufacturers apply a ceramic coating on conventional polyolefin separators. A coating can impede ion flow through the separator, reducing battery cycle life and performance. Further, it can crack or flake off, potentially contaminating the cell," explains John Shelburne, PPT’s Director of Research and Development.