The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 19, 2001
Filed:
Jan. 07, 1999
Steven J. Visco, Berkeley, CA (US);
May-Ying Chu, Oakland, CA (US);
Lutgard C. De Jonghe, Lafayette, CA (US);
PolyPlus Battery Company, Inc., Berkeley, CA (US);
Abstract
Disclosed is an electrochemical device having a shuttle-type redox mechanism for overcharge protection in which the redox reaction is “tuned” with a tuning agent to adjust the potential at which the redox reaction occurs. Such device may be characterized as including the following elements: (1) a negative electrode (e.g., lithium); (2) a positive electrode containing one or more intermediate species (e.g., polysulfides) which are oxidized to one more oxidized species during overcharge; and (3) a tuning species (e.g., an organosulfur compound) which adjusts the rate at which the oxidized species are reduced and thereby adjusts the voltage at which overcharge protection is provided. The oxidized species produced during overcharge move to the negative electrode where they are reduced back to said intermediate species as in a normal redox shuttle. However, the oxidized species react more rapidly than the intermediate species at the negative electrode. Thus, the overcharge protection mechanism becomes more active as the oxidized species' concentration increases—as occurs during more severe overcharge.