Nanocomposite for fuel cell, method of preparing the nanocomposite, and fuel cell including the nanocomposite

• US 8,084,167 B2
• Filed: 11/14/2007
• Issued: 12/27/2011
• Est. Priority Date: 01/24/2007
• Status: Expired due to Fees

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Lee, Jeong-hee, Choi, Jae-young, Pak, Chan-ho, Ra, Eun-ju, Lee, Young-hee, An, Kay-hyeok
• Primary Examiner(s): Alejandro, Raymond
• Application Number:
  US11/985,531
• Publication Number:
  US 20080176129A1
• Time in Patent Office: 1,504 Days
• Field of Search: 429/523, 429/530, 429/532, 429/533, 429/534
• US Class Current: 429/523
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: D01F 11/04 of synthetic polymers
• CPC Class Codes: D01F 9/20 from polyaddition, polycondensation or polymerisation products D01F9/145, D01F9/16, D01F9/18 take precedence
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: H01M 4/9083 on carbon or graphite
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: H01M 4/926 on carbon or graphite
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 977/948 Energy storage/generating using nanostructure, e.g. fuel cell, battery

Abstract

Provided is a nanocomposite for the catalyst layer of a fuel cell electrode including: a carbon nanofiber; and metal catalyst particles uniformly applied to the surface of the carbon nanofiber, wherein the carbon nanofiber has a surface oxygen content of at least 0.03 calculated by the formula: Oxygen content=[atomic percentage of oxygen/atomic percentage of carbon] using atomic percentages of oxygen and carbon, respectively calculated from an area of an oxygen peak having a binding energy of 524 to 540 eV, an area of a nitrogen peak having a binding energy of 392 to 404 eV, and an area of a carbon peak having a binding energy of 282 to 290 eV in X-ray photoelectron spectroscopy. The nanocomposite according to the present invention has high surface oxygen content and has metal catalyst nano particles densely and uniformly distributed on the outer wall of the carbon fibers, thereby having high electrochemical efficiency. Thus, efficiency of fuel cells can be improved using the nanocomposite.

Claims

1. A carbon nanofiber for a fuel cell electrode having a surface oxygen content of 0.14 to 0.2, calculated using Formula 1 using atomic percentages of oxygen and carbon, respectively calculated from an area of an oxygen peak having a binding energy from 524 to 540 eV, an area of a nitrogen peak having a binding energy from 392 to 404 eV, and an area of a carbon peak having a binding energy from 282 to 290 eV in X-ray photoelectron spectroscopy:

Oxygen content=[atomic percentage of oxygen/atomic percentage of carbon] 

 

Formula 1,

and wherein the carbon nanofiber is sintered and configured as part of a fuel cell.

2. A nanocomposite for a fuel cell electrode comprising:

a carbon nanofiber; and

metal catalyst particles uniformly applied to the surface of the carbon nanofiber, wherein the carbon nanofiber has a surface oxygen content of 0.14 to 0.2, calculated using Formula 1 using atomic percentages of oxygen and carbon, respectively calculated from an area of an oxygen peak having a binding energy from 524 to 540 eV, an area of a nitrogen peak having a binding energy from 392 to 404 eV, and an area of a carbon peak having a binding energy from 282 to 290 eV in X-ray photoelectron spectroscopy;

Oxygen content=[atomic percentage of oxygen/atomic percentage of carbon] 

 

Formula 1,

and wherein the nanocomposite is sintered and configured as part of a fuel cell.

3. The nanocomposite of claim 2 further comprising metal catalyst particles on the surface of the nanofiber, wherein an average particle size of the metal catalyst particles is from 2 to 5 nm.

4. The nanocomposite of claim 2 in a web or paper form.

5. An electrode for a fuel cell comprising a nanocomposite according to claim 2.

6. The electrode of claim 5 without a binder or an ionomer.

7. The electrode of claim 5 further comprising an integrated diffusion layer and a catalyst layer.

8. A fuel cell comprising an electrode having a nanocomposite according to claim 2.

9. The fuel cell of claim 8 without a binder or an ionomer.