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:
Jan. 07, 1997
Filed:
Apr. 20, 1995
Toru Nagaura, Fukuoka, JP;
Hival Ltd., Fukuoka, JP;
Abstract
The present invention provides nonaqueous electrolyte secondary cells capable of withstanding severe overdischarge to obtain nonaqueous electrolyte secondary batteries having satisfactory cycle characteristics. A spinel-type lithium-containing metallic oxide represented by LiM.sub.2 O.sub.4 (where M is a transitional metal element) is used as an active substance for each of the positive and negative electrodes of the cell embodying the invention. In an organic electrolyte containing lithium ion, the spinel-type lithium-containing metallic oxide represented by LiM.sub.2 O.sub.4 is capable of reversibly undergoing an electrochemical oxidation reaction involving removal of doping lithium ion and also an electrochemical reduction reaction involving lithium ion doping. Accordingly, when the cell of the invention is overdischarged (.apprxeq. reversibly charged), a reversible reaction involving lithium ion doping/undoping occurs at the positive electrode and negative electrode without entailing any damage due to overdischarge. As a result, when many cells are connected in series to obtain a battery, the cycle characteristics of the battery are not impaired even if the component cells are different in capacity.