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:
Sep. 22, 2015
Filed:
Jan. 19, 2012
Yogesh Kumar Anguchamy, Newark, CA (US);
Charan Masarapu, Fremont, CA (US);
Haixia Deng, Fremont, CA (US);
Yongbong Han, San Francisco, CA (US);
Subramanian Venkatachalam, Pleasanton, CA (US);
Sujeet Kumar, Newark, CA (US);
Herman A. Lopez, Sunnyvale, CA (US);
Yogesh Kumar Anguchamy, Newark, CA (US);
Charan Masarapu, Fremont, CA (US);
Haixia Deng, Fremont, CA (US);
Yongbong Han, San Francisco, CA (US);
Subramanian Venkatachalam, Pleasanton, CA (US);
Sujeet Kumar, Newark, CA (US);
Herman A. Lopez, Sunnyvale, CA (US);
Envia Systems, Inc., Newark, CA (US);
Abstract
A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m/g to about 200 m/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cmto about 3.5 mg/cm. In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.