Nippon Chemi-Con Corp has been developing a new type of capacitors called “nano-hybrid capacitor” and plans to launch the first samples on the market by April 2011. These new capacitors generation will be introduced as replacement to the normal electric double layer capacitor (EDLC) and will have an energy density several times higher than that of a EDLC.
Nippon Chemi-Con developed the nano-hybrid capacitor in collaboration with a professor from the Tokyo University of Agriculture and Technology, Katsuhiko Naoi.
The difference from the EDLC is the negative electrode, made of carbon nanofibers (CNFs) added with nanocrystalline lithium titanate (Li4Ti5O12). At this moment there are in development 2 types of capacitors made for commercialization purposes, with a nominal voltage of 2.8V and a winding structure:
– the high-energy type which has an output density slightly lower but an energy density about three times higher than that of an EDLC, and
– the high-output type, which has an output density equivalent to that of an EDLC but the energy density is twice as high as that of an EDLC.
For large-capacitance, some manufacturers have developed Lithiun-ion(Li-ion) capacitors(LiC) but those have major disadvantages at least for now. Even though the energy density is five times higher than that of an EDLC, the manufacturing costs of a LiC are quite high and the properties at lower temperatures are inferior. All LiCs require a “pre-dope” process, where the negative electrode is impregnated with Li-ions and besides this the collectors are made of copper.
The price of the nano-hybrid capacitors is equivalent to or lower than that of an EDLC because of its high energy density, while at low-temperature the deduction coefficient of capacity is -10% at a temperature of -20%°C (LiC’s go even to -30% capacity loss). The goal is to achieve for the nano-hybrid capacitors a capacity loss equivalent to that of an EDLC. Serial production is expected to start in the Spring of 2012, depending on the market response to the samples NCC plans for next year.
