High Porosity Polymer Separators for High Power Lithium-ion Batteries

Period of Performance: 07/31/2003 - 01/31/2004


Phase 1 SBIR

Recipient Firm

Boundless Corp.
2500 Central Avenue, Suite L
Boulder, CO 80301
Principal Investigator


Boundless Corporation, supported by inventor Kirby Beard, proposes to develop a new micro-porous separator for THAAD, Patriot and other advanced missile technologies requiring high power lithium-based batteries for increased agility, speed and range. Based on a proprietary pore forming material, it promises higher porosity (80% +) with sub-micron pore sizes, excellent mechanical strength and very low production costs. Projected conductivity of up to 8 mS/cm (20oC) could nearly double its power capacity versus Bellcore (4.0 mS/cm) or Celgard technology (est. ~5 mS/cm). Bellcore technology requires costly extraction processing and can leave residual plasticizer, degrading performance. Celgard loses mechanical integrity above 55% porosity, limiting its power capability. Both older technologies are relatively expensive due to complex processing. The new process requires only simple mixing, coating and drying equipment and avoids all post-processing techniques such as extraction, stretching, leaching, etc. often used in producing other separators. Its one-step casting procedure uses low cost solvent systems and will yield estimated cost savings of up to 90% compared to Celgard. It is also amenable to inexpensive plastic substrates like PVC. A potentially broad breakthrough in battery separator technology, it might also enhance performance of aqueous NiCd, lead-acid, and other batteries. Lockheed Martin Missile and Fire Control identifies future generations of THAAD and Patriot missiles and unmanned combat aerial vehicles as key applications for high power lithium batteries, for critical operations such as radar targeting, imaging and jamming. Powerful, periodically testable secondary batteries may replace thermal batteries in many applications. High power commercial batteries are critical to the widespread acceptance of hybrid electric vehicles, and some experts predict all new vehicles will be electric-assist hybrids in ten years. The lithium-ion battery market is projected to reach $3.2 billion by 2007, with an estimated Li-Ion separator market of $160 million. Manufacturers will seek out Boundless' new separator technology to enable higher power from existing electrochemistries and reduce separator costs by as much as 90%. Boundless commercial partners and licensing agreements will help maximize the market penetration of this exciting technology.