Graphite powder suitable for negative electrode material of lithium ion secondary batteries
CA 2247319 C · Owner: Kaminaka, Hideya · Inventors: Yonemura, Mitsuharu; Kamei, Kazuhito; Abe, Masaru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A graphite powder has surface closed-end structures in which the graphite c-plane layers of the graphite layer crystal lattices have closed-ends on the surface of the graphite powder by linking the ends of one or more pairs of the c-plane layers leaving interstices which are open on the surface of the graphite. The number of open interstices is at least 100 and at most 1500 per micrometer in a c-axis direction of the graphite. Preferably the graphite powder has a specific surface area of 1.0 m2/g or less. Such a graphite powder can be prepared either by graphitizing a carbon material, which has been pulverized at a high speed under well-controlled conditions before and/or after the …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 25, 1997 and granted December 24, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 25, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 25, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.