Carbon nanotube based pastes

• US 8,540,902 B2
• Filed: 01/13/2011
• Issued: 09/24/2013
• Est. Priority Date: 01/13/2010
• Status: Active Grant

• Current Assignee: Cnano Technology Limited
• Original Assignee: Cnano Technology Limited
• Inventors: Xing, Caihong, Wang, Jianfeng, Wei, Zhaojie, Ma, Jun, Tsai, Ching-Jung, Li, Qi
• Primary Examiner(s): Kopec, Mark
• Assistant Examiner(s): THOMAS, JAISON P
• Application Number:
  US13/006,266
• Publication Number:
  US 20110171364A1
• Time in Patent Office: 985 Days
• Field of Search: 252500-5216, 252/511, 427/77, 977/752
• US Class Current: 252/511
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 3/041 Carbon nanotubes
• CPC Class Codes: C09D 139/06 Homopolymers or copolymers of N-vinyl-pyrrolidones
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09D 7/45 Anti-settling agents
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Carbon-nanotube based pastes and methods for making and using the same are disclosed. Carbon nanotubes are dispersed via milling; resultant paste has Hegman scale of greater than 7. The pastes can be used as electro-conductivity enhancement in electronic devices such as batteries, capacitors, electrodes or other devices needing high conductivity paste.

Claims

1. A battery electrode coating composition consisting of:

multi-walled carbon nanotubes of diameter greater than 4 nm;

a dispersant chosen from a group consisting of poly(vinylpyrrolidone) (PVP), poly(styrene sulfonate) (PSS), poly(phenylacetylene) (PAA), poly(meta-phenylenevinylene) (PmPV), polypyrrole (PPy), poly(p-phenylene benzobisoxazole) (PBO), natural polymers, amphiphilic materials in aqueous solutions, anionic aliphatic surfactant, sodium dodecyl sulfate (SDS), cyclic lipopeptide biosurfactant, surfactin, water-soluble polymers, carboxyl methyl cellulose, hydroxyl ethyl cellulose, poly(vinyl alcohol), PVA, sodium dodecyl sulfate, SDS, polyoxyethylene surfactant, poly(vinylidene fluoride), PVdF, carboxyl methyl cellulose (CMC), hydroxyl ethyl cellulose (HEC), polyacrylic acid (PAA), polyvinyl chloride (PVC) and combinations thereof;

a liquid vehicle chosen from a group consisting of water, alcohols, ethers, aromatic hydrocarbons, esters, ketones, n-methyl pyrrolidone and mixtures thereof;

lithium ion battery electrode materials chosen from a group consisting of lithium, oxygen, phosphorous, sulphur, nitrogen, nickel, cobalt, manganese, vanadium, silicon, carbon, aluminum, niobium and zirconium and iron;

and wherein a paste composition consisting of the multi-walled carbon nanotubes, the dispersant and the liquid vehicle which has carbon nanotubes present in the range of about 1 to 15% by weight, a bulk electrical resistivity of about 10<sup>−

1</sup> Ω

-cm or less, and a viscosity greater than about 5,000 cps, is present in a range from about 2% to about 50% by weight of the coating composition.

2. The battery electrode coating composition of claim 1 further consisting of a polymeric binder.

3. The battery electrode coating composition of claim 1 wherein the battery electrode coating composition is contacting a metallic surface to form an electrode for a lithium ion battery and the liquid vehicle is removed.