Licensable Technology
Inventions Resulting from Penn State Energy Research
High Surface Area Carbon for Ultracapacitors and Other Applications
By R. Rajagopalan, K. Perez, H. Foley
Penn State Invention Disclosure No. 2006-3203
Field of Invention
Ultracapacitors; specialty carbon
Background
Activated carbons are the most widely used electrode material for ultracapacitors because of their high surface area and relatively good electrical conductivity. However, the performance of these capacitors is only slightly correlated with the specific surface area of the activated carbons because of the influence of other factors such as the pore size. Although activated carbons have been prepared with very high specific surface areas, they usually possess a very wide pore size distribution which introduces significant drawbacks in the properties of electrodes thus limiting their performance (e.g. energy & power density) in ultracapacitor applications. For this and other applications, it is desirable to produce a high surface area carbon having a narrow pore size distribution that can be manufactured from inexpensive raw materials. These are the needs addressed by the present invention.
Invention Description
The invention is a high surface area carbon with tunable microporosity and mesoporosity derived from coal tar pitch/polymer blends. We use a very inexpensive precursor providing an excellent yield of carbon. The porosity is concentrated within a relatively narrow range and is highly tunable by varying the molecular weight of the pore forming material. A further advantage of the technology is that it does not involve any post treatment of activated carbon to remove impurities. Electric double layer capacitor (EDLC) prototypes having a specific capacitance of about 180 F/g were made using H2SO4 as the electolyte. Performance of the EDLC was fairly stable over hundreds of cycles. These materials will make excellent candidates for electrodes providing high specific capacitance (per volume and mass) in EDLCs.
Applications/Advantages
- Ultracapacitors, batteries, fuel cells, gas storage, adsorbents
- High surface area in the range of 1500-2000 m2/g
- More than 70% of pores in the range of 7-20 Ǻ
- Derived from economical coal tar pitch
- High specific capacitance of at least 180 F/g
- Low performance loss over hundreds of cycle
Contact
Matthew D. Smith
Intellectual Property Office
mds126@psu.edu