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:
Jul. 22, 2014
Filed:
Aug. 05, 2010
Takeshi Abe, Toyota, JP;
Yohei Shindo, Toyota, JP;
Akira Tsujiko, Toyota, JP;
Machiko Abe, Toyota, JP;
Keiko Wasada, Toyota, JP;
Takeshi Abe, Toyota, JP;
Yohei Shindo, Toyota, JP;
Akira Tsujiko, Toyota, JP;
Machiko Abe, Toyota, JP;
Keiko Wasada, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, Aichi-ken, JP;
Abstract
Provided is a lithium-ion secondary battery having an excellent initial capacity as well as a good capacity retention rate. The battery comprises a positive electrode comprising a positive electrode active material, a negative electrode comprising a negative electrode active material, and a non-aqueous liquid electrolyte. The negative electrode active material comprises a graphitic material that satisfies each of the following properties: (a) in its Raman spectrum obtained by Raman scattering analysis using an exciting light at a wavelength of 532 nm, having a ratio of its D-peak intensity Ito its G-peak intensity I, an R value (I/I), of 0.15 or smaller; and (b) having a full width at half maximum of the G peak, Δv, of 23 cmor smaller. The secondary battery has a capacity retention rate of 70% or greater when subjected to 500 cycles of charging and discharging at a constant current rate of 2 C at 60° C.