Dupont Safety & Construction, Inc.

E.i. Dupont De Nemours and Company

Byoung Sam Kang

Mehdi Afshari

Sang Woo Lee

Mikhail R Levit

Brian R France

A laminate useful as cell-to-cell battery insulation, the laminate having an insulating area and a periphery seal area, the insulating area comprising, in order: a first outer layer of paper comprising aramid material and mica; an inner layer comprising a felt or paper of inorganic short fibers; and a second outer layer of paper comprising aramid material and mica; the periphery seal area being void of the inner layer and being formed by adhering the first and second outer layers of paper to one another; wherein the periphery seal area extends around the periphery of the insulating area.

Fire-retardant insulation suitable for battery cells

A paper suitable for use in a battery or battery pack as a flame barrier or thermal insulation, the paper comprising 60 to 95 weight percent aerogel powder and 5 to 40 weight aramid polymer fibrils; the paper having a thickness of 50 to 4000 micrometers.

Papers comprising aerogel powder and aramid polymer fibrils

A paper suitable for use as a cell-to-cell flame barrier in a battery, and a battery comprising the paper, the paper comprising 40 to 70 weight percent fibrids and 30 to 60 weight percent mica, based on the total weight of the fibrids and mica in the paper; wherein the fibrids comprise a blend of 80 to 20 weight percent polymer and 20 to 80 weight percent aerogel powder, based on the total weight of the polymer and aerogel powder in the fibrids; the paper having a thickness of 100 to 4000 micrometers.

Papers useful as thermal insulation and flame barriers for battery cells

A paper suitable for use as a separator or thermal or fire insulation for use in or with electrochemical cells, and an electrochemical cell comprising the same, the paper having 90 to 99 weight percent aramid fibrous pulp comprising aramid polymer fibrils and 1 to 10 weight percent polyvinylpyrrolidone present as a coating on the surface of the fibers, the paper having a thickness of 10 to 40 micrometers and a tensile strength of at least 15 megapascals or greater.

Paper comprising aramid pulp suitable for electrochemical cells, and electrochemical cells made therefrom

A paper suitable for use as a separator paper in electrochemical cells and an electrochemical cell comprising same, the paper comprising as the sole fibrous components 95 to 100 weight percent fibrils and 0 to 5 weight percent aramid fibrids and having a thickness of 10 to 40 micrometers and a tensile strength of at least 15 megapascals or greater, the fibrils comprising a polymer blend of 80 to 96 weight percent polyparaphenylene terephthalamide and 4 to 20 weight percent of polyvinylpyrrolidone; the fibrils having a diameter of 10 to 2000 nanometers, a length of 0.2 to 3 millimeters, a surface area of 3 to 40 square meters/gram, and a Canadian Standard Freeness of 0 to 10 milliliters.

High tensile strength paper suitable for use in electrochemical cells

A tape having a first face comprising a continuous surface of mica paper and a second face comprising a support layer, wherein the mica paper comprises 70 to 99 weight percent mica and 1 to 30 weight percent binder and the support layer comprises a film, a paper, a nonwoven fabric, or a woven fabric; wherein the initial elongation of the support layer is equal to or less than the initial elongation of the mica paper; and wherein the support layer is demountably attached to the mica paper such that when a delamination force of 10 N/10 mm or less is imposed on the support layer it can be separated from the mica paper.

Method of wrapping mica paper on an electrical conductor and mica paper tape suitable for same

This invention pertains to a laminate structure suitable for use as electrical insulation, comprising a first paper layer comprising 90 to 99 weight percent uniformly distributed calcined mica and 1 to 10 weight percent supporting material, a majority by weight of the supporting material being in the form of a floc; and a support layer comprising unidirectional filaments or unidirectional yarns or woven yarns; wherein the support layer is bound to the first paper layer; the laminate structure having a dielectric strength of 15 kV/mm or greater, a Gurley porosity of 400 seconds or less, and total mica content of 60 weight percent or greater. The laminate structure can further comprise a second paper layer bound to the support layer, the second paper layer comprising 90 to 99 weight percent uniformly distributed calcined mica and 1 to 10 weight percent supporting material, a majority by weight of the supporting material being in the form of a floc.

Resin-compatible laminate structures

Laminate structure suitable for use as electrical insulation comprising:

Corona-resistant resin-compatible laminates

A method is disclosed of applying a mica paper around an electrical conductor, the process including attaching the tape comprising the mica paper to the conductor at an attachment point on the conductor; winding the tape around the conductor surface until the tape has been wound to a point that is at least 25 percent of the conductor circumference from the attachment point and then initiating a continuous removal of the support layer from the tape, starting at the attachment point; the mica paper remaining in contact with the surface of the conductor; and continuing to wind the tape around the conductor while simultaneously removing the support layer at a removal point until a desired amount of conductor surface is completely covered with at least one layer of the mica paper, with the proviso that the removal point is maintained at least 25 percent of the conductor circumference behind the winding point until the desired amount of conductor surface is completely covered. A tape is also disclosed of mica paper and a support layer, wherein the mica paper; wherein the initial elongation of the support layer is equal to or less than the initial elongation of the mica paper; and wherein the support layer is demountably attached to the mica paper such that when a delamination force of 10 N/10 mm or less is imposed on the support layer it can be separated from the mica paper.

A multilayer structure particularly useful in a transformer which contains

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Midlothian, VA, United States of America

Byoung Sam Kang