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Preparation of Silver Vanadium Oxide Using Controlled Sintering Technology

IP.com Disclosure Number: IPCOM000124051D
Publication Date: 2005-Apr-07
Document File: 8 page(s) / 53K

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Abstract

This invention relates to the preparation of a new transition metal oxide cathode material for use in non-aqueous electrolyte lithium batteries. The transition metal oxide cathode material is preferably silver vanadium oxide prepared by controlled sintering technology. The new silver vanadium oxide material may be prepared by one of several different synthesis techniques followed by controlled sintering to produce a material with a desired specific surface area. The specific surface area of the SVO directly impacts the current-carrying capability of the cathode material, and thus this new method of producing SVO provides great control over the performance of the electrochemical cell.

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Wilson Greatbatch Ltd.

Patent Disclosure

Title: Preparation of Silver Vanadium Oxide Using Controlled Sintering Technology.

Date:  June 26, 2003

Inventors: Esther Takeuchi, Veronica Lamothe, Randy Leising

Laboratory Notebook No.     R407                Pages:  18, 26, 27, 29, 32-40

Laboratory Notebook No.     R409                Pages:  63-81

Field of the Invention

            This invention relates to the preparation of a new transition metal oxide cathode material for use in non-aqueous electrolyte lithium batteries.  The transition metal oxide cathode material is preferably silver vanadium oxide prepared by controlled sintering technology.   The new silver vanadium oxide material may be prepared by one of several different synthesis techniques followed by controlled sintering to produce a material with a desired specific surface area.  The specific surface area of the SVO directly impacts the current-carrying capability of the cathode material, and thus this new method of producing SVO provides great control over the performance of the electrochemical cell.

Description of the Prior Art

            Silver vanadium oxide (SVO) has been synthesized in the prior art by solid-state thermal decomposition, combination, or both decomposition and combination reactions.  Decomposition reactions to produce SVO are detailed in U.S. Patents 4,310,609 and 4,391,729 (Liang, et al).  The synthesis of SVO as described by Liang was conducted at a temperature of 360-375ºC.  The effects of synthesis temperature on physical and electrochemical properties of SVO prepared by the decomposition reaction are discussed in Leising, R.A.; Takeuchi, E.S. Chem. Mater. 1993, 5, 738-742.  Samples in this study were prepared by heat treatment of a mixture of AgNO3 and V2O5 at temperatures ranging between 320ºC to 540ºC.  Crespi, et al. in U.S. Patent 5,221,453 describes the preparation of SVO via combination reaction, where thermal combination of Ag2O and V2O5 to form SVO was accomplished at a final temperature of 520ºC.   Synthesis of SVO via a dual decomposition/combination reaction at 500ºC is described in the publication Leising, R.A.; Takeuchi, E.S. Chem. Mater. 1994, 6, 489-495.  The synthesis of SVO by a decomposition/combination reaction is also described in U.S. Patent 6,566,007 (Takeuchi & Leising), where the SVO is prepared using a final temperature of 490 to 520ºC.  All of these prior art SVO synthesis procedures share a high temperature (>320ºC) thermal treatment step as a common process.

            There are several methods that can be used to produce SVO at low temperatures resulting in feedstock materials for the controlled sintering technology described in this disclosure.  One such synthesis technique is sol-gel technology.  Sol-gel techniques have been used in the past to produce metal oxides, such as the synthesis of vanadium bronzes as reported by L. Snaidi...