Other

Advanced Membrane Systems, Inc.

Daramic, Inc.

Abbas Samii

Garrin Samii

David Veno

Banafsheh Behnam

Wai Ming Choi

Dave C Veno

A method for manufacturing battery separators for use in a lithium-ion battery containing non-aqueous electrolytes, producing batteries being resistant to thermal runaway and explosion, includes the steps of preparing a dryblend comprising two UHMW Polyethylenes and Calcined Kaolin, feeding said dry-blend into an extruder, melt-kneading said dry blend in the extruder while feeding mineral oil, making a solution from a die into the form of a sheet, using casting rolls, thereby cooling the solution down, producing a thick gel sheet, stretching the gel sheet in both machine and transverse directions, producing a 20 micron thick gel sheet containing oil thereby, extracting the oil by use of a solvent and drying the film, heat-setting the film and producing a microporous membrane.

Separator for non-aqueous lithium-ion battery

A ceramic microporous polyolefin battery separator membrane, high in air permeability, low in shrinkage and improved temperature resistance addresses the safety requirements of lithium ion batteries. The separators made by the current invention consists of one or more polyolefin polymers and kaolin fillers comprised of aluminum oxide and silicon oxide. The membranes of current invention have a thickness of 5-200 microns, air permeability of 1-200 sec/10 cc (Gurley seconds), and average pore diameter of less than 1 micron.

Polyolefin and ceramic battery separator for non-aqueous battery applications

A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130-140 degrees C. and melt integrity greater than 165 degrees C. It consists of 20-30% by weight of a UHMW polyethylene having Mw of 1&#xd7;10or higher, 60-70% by weight of a HDPE having average Mw of between 200,000-500,000 and 5-15% by weight of TiOwith an average particle size of less than 0.2 microns.

Shutdown separators with improved properties

A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130-140 degrees C. and melt integrity greater than 165 degrees C. It is made of UHMWPE having a weight-average molecular weight of 1&#xd7;10or more and an inert filler. A second microporous polyolefin battery separator has a shutdown temperature of between 95 and 110 degrees C. and a melt integrity of more than 165 degrees C. It is made from an UHMWPE having a weight-average molecular weight of 1&#xd7;10or more, a shutdown (LMWPE) having a weight-average molecular weight of 4500 or less and an inert filler. Both membranes have a thickness of 5-75 microns, a porosity of 30-95%, an air permeability of 1-200 sec/10 cc, an average pore diameter of 0.001 to 1 micron and puncture strength of more than 300 grams/25 &#x3bc;m.

A microporous polyolefin battery separator membrane is extremely high in porosity, high in puncture strength, very low in shrinkage and with shutdown temperature of 130&#x2013;140 degrees C. and melt integrity greater than 165 degrees C. It is made of UHMWPE having a weight-average molecular weight of 1&#xd7;10or more and an inert filler. A second microporous polyolefin battery separator has a shutdown temperature of between 95 and 110 degrees C. and a melt integrity of more than 165 degrees C. It is made from an UHMWPE having a weight-average molecular weight of 1&#xd7;10or more, a shutdown (LMWPE) having a weight-average molecular weight of 4500 or less and an inert filler. Both membranes have a thickness of 5&#x2013;75 microns, a porosity of 30&#x2013;95%, an air permeability of 1&#x2013;200 sec/10 cc, an average pore diameter of 0.001 to 1 micron and puncture strength of more than 300 grams/25 {circumflex over (l)}&#xbc; m.

A separator membrane for use in silver-zinc batteries is produced by extruding a blend of two fillers with the same chemical formula but different particle size. A polyolefine polymer and a plasticizer are blended and extruded to form a thin sheet of 1 to 10 mil thickness. The plasticizer is then extracted to leave submicron voids in the membrane. Plasticizers are added as processing aids, and can be either soluble or insoluble in water, and include petroleum oils, lubricating oils, fuel oils, and natural oils such as tall oils and linseed oils. The oil are then extracted from the membrane by conventional procedures such as single stage extraction using a suitable solvent. Commercially available wetting agents known to the art such as dodecylphenoxy polyethoxy ethanol and isooctyl phenyl polyethoxy ethanol are coated onto the sheet to improve wettability. The sheet is then dried, and boiled in distilled water for one minute or more, before being finally dried.

Microporous membrane battery separator for silver zinc batteries

A battery separator having sodium sulfate incorporated therein in order to reduce and/or eliminate hydration short problems in batteries. The preferred method of adding sodium sulfate directly to the separator is via the use of sodium sulfate-containing silica as a separator filler added during the process of manufacturing the separator. The present invention is also directed to a battery separator containing a relatively high level of sodium sulfate, and to batteries which incorporate such separators.

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Belmont, MA, United States of America

Abbas Samii