US 2003/0198869 A1 · Cross-linked polysiloxanes

Abstract

Disclosed herein are cross-linked polysiloxane polymers having oligooxyethylene side chains. Lithium salts of these polymers can be synthesized as a liquid and then caused to solidify in the presence of elevated temperatures to provide a solid electrolyte useful in lithium batteries.

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Claims54

Dependent claims

A cross-linked polysiloxane having at least one main chain segment in which some silicons are linked to a side chain selected from the group consisting of side chains of the following formula:

—(CH2)3—O—(CH2CH2O)p—R1, wherein p is at least 2 and R1 includes carbon.

Dependencies are inferred from the claim text.

Abstract

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Claims54

Dependent claims

A cross-linked polysiloxane having at least one main chain segment in which some silicons are linked to a side chain selected from the group consisting of side chains of the following formula:

—(CH2)3—O—(CH2CH2O)p—R1, wherein p is at least 2 and R1 includes carbon.

Dependencies are inferred from the claim text.

Description4,014 words

Summary1,023 words

#The present invention relates to cross-linked siloxane polymers capable of being formed in a liquid reaction medium and solidified by heating. It also relates to the use of such polymers with salts (such as lithium salts) to create electrically conductive materials for use in batteries and the like.

#Lithium batteries are used in medical devices, wristwatches, cell phones, and computers, and are of interest for powering electrically powered automobiles. They are particularly desirable because they deliver high levels of power per unit weight. However, conventional lithium batteries typically contained a liquid (such as polyethylene oxide) that acted as an electrolyte. If such batteries were to be used in automobiles or in an implanted medical device, there would be some risk that the liquid might leak, with resulting safety and environmental concerns.

#For the above reasons, there is a need for solid electrolytes suitable for use with batteries.

Brief description of the drawings6 figures

#FIG. 1 depicts in schematic form a synthesis of a first type of precursor polysiloxane;

#FIG. 2 depicts in schematic form a synthesis of a second type of precursor polysiloxane;

#FIG. 3 depicts in schematic form a method of obtaining one type of cross-linking agent;

Detailed description2,901 words

#We describe creation of polysiloxane polymers having a plurality of main siloxane chain silicons linked to at least one oligomer side chain and a plurality of main siloxane chain silicons linked to a hydrogen available for use in a later cross-linking reaction. We describe the creation of cross-linking agents based on either polyethylene oxide main chain portions (with available unsaturated carbon ends) or siloxane main chain portions (with available unsaturated carbon ends).

#We also describe the use of such cross-linking agents to create cross-linked polysiloxane material (with or without lithium salt doping).

#We also describe testing of the conductivity of our electrolytes, a technique for controlling the speed of the cross-linking reaction, and techniques for turning the liquid cross-linked polysiloxane into a solid.

Cross-linked polysiloxanes

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Abstract

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Claims54

Cross-linked polysiloxanes

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims54

Description4,014 words

Drawings

Classification16 codes

Life of this patent

Description4,014 words