A supercapacitor module is provided. In some embodiments, the supercapacitor can include a first supercapacitor, a second supercapacitor, and an interconnect electrically connecting the first and second supercapacitors in series. A casing can encapsulate at least the first and second supercapacitors. The operating voltage of the supercapacitor module can be greater than 3.5 volts, and the equivalent series resistance of the supercapacitor module can be less than about 10 ohm.