文档介绍:附录一:外文原文
Super capacitors - An Overview
Key words: Electrostatic capacitor; Electrolytic capacitor; Ceramic capacitor; Electrical double layer capacitor; Super Capacitor
INTRODUCTION
This paper offers a concise review on the renaissance of a conventional capacitor to electrochemical double layer capacitor or super capacitor. Capacitors are fundamental electrical circuit elements that store electrical energy in the order of microfarads and assist in filtering. Capacitors have two main applications; one of which is a function to charge or discharge electricity. This function is applied to smoothing circuits of power supplies, backup circuits of puters, and timer circuits that make use of the periods to charge or discharge electricity. The other is a function to block the flow of DC. This function is applied to filters that extract or eliminate particular frequencies. This is indispensable to circuits where excellent frequency characteristics are required. Electrolytic capacitors are next generation capacitors which mercialized in full scale. They are similar to batteries in cell construction but the anode and cathode materials remain the same. They are aluminum, tantalum and ceramic capacitors where they use solid/liquid electrolytes with a separator between two symmetrical electro des.
An electrochemical capacitor (EC), often called a Super capacitor or Ultra capacitor, stores electrical charge in the electric double layer at a surface-electrolyte interface, primarily in high-surface-area carbon. Because of the high surface area and the thinness of the double layer, these devices can have very a high specific and volumetric capacitance. This enables them bine a previously unattainable capacitance density with an essentially unlimited charge/discharge cycle life. The operational voltage per cell ,limited only by the breakdown potential of the electrolyte, is usually<1 or <3 volts per cell for aqueous anic electrolytes respectively.
The concept of storing electri