초록 ▼

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 ne

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.

대표청구항 ▼

[ What is claimed is:] [1.]1. A rechargeable electrochemical energy conversion device resisting damage from overcharge, the rechargeable electrochemical energy conversion device comprising:a positive electrode other than a sulfur electrode;a negative electrode;a sulfur-based additive including at le

[ What is claimed is:] [1.]1. A rechargeable electrochemical energy conversion device resisting damage from overcharge, the rechargeable electrochemical energy conversion device comprising:a positive electrode other than a sulfur electrode;a negative electrode;a sulfur-based additive including at least one of elemental sulfur, a sulfide species, and a polysulfide species; andan electrolyte in which the polysulfide species, if present, are substantially soluble and the sulfide species, if present, is substantially insoluble, whereby during overcharge a polysulfide species is oxidized to an oxidized polysulfide species which is subsequently reduced by a reaction with the substantially insoluble sulfide species.