Patent attributes
Disclosed is an improved type of fluorinated carbon (CFx) for use in electrical storage devices such as batteries and capacitors. The CFx is coated with a conductive material such as gold or carbon using vapor deposition. The resulting material exhibits better conductivity with concomitant lower impedance, higher electrical stability, and improved potential throughout the useful life of the device, as compared to uncoated CFx. The improved conductivity reduces the amount of nonactive material (e.g., carbon black) that needs to be added, thus improving the volumetric energy density. In addition, cells made with the subject CFx exhibit more constant voltages and higher overall voltage (2.0 volts with a lithium metal anode) throughout their useful life. Chemical or physical vapor deposition techniques to deposit a variety of metals or carbon may be used to create the improved CFx. The coated CFx may be used in primary or secondary batteries, as well as capacitors and hybrid devices. Methods for making and using the coated CFx are described.
