Friday, July 02, 2010

US Patent 7745047 - Nanographene platelets for Li ion batteries

Nanotek Instruments is developing new low-cost nanomaterials for applications including solar cells, batteries, and fuel cells. This latest patent is related to Li ion batteries using graphene platelets to form one of the electrodes. Claim 1 reads:

1. A nano-scaled graphene platelet-based composite composition for use as a lithium ion battery anode, said composition comprising:

a) micron- or nanometer-scaled particles or coating which are capable of absorbing and desorbing lithium ions; and

b) a plurality of separated or isolated nano-scaled graphene platelets (NGPs), wherein a platelet comprises a graphene sheet or a stack of graphene sheets having a platelet thickness less than 100 nm;

wherein at least one of said particles or coating is physically attached or chemically bonded to at least one of said platelets and the amount of platelets is in the range of 2% to 90% by weight and the amount of particles or coating is in the range of 98% to 10% by weight;

wherein the particles or coating comprises an active material capable of absorbing or extracting lithium ions and said active material is selected from the group consisting of:

(a) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), and cadmium (Cd);

(b) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, or Cd with other elements, wherein said alloys or compounds are stoichiometric or non-stoichiometric;

(c) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Fe, or Cd, and their mixtures or composites;

(d) salts and hydroxides of Sn; and

(e) combinations thereof.