不同N掺杂构型石墨烯的量子电容研究

Quantum capacitance performance of different nitrogen doping configurations of graphene

超级电容器是一种利用界面双电层储能或在电极材料表面及近表面发生快速可逆氧化还原反应而储能的装置,其特点是功率密度高、循环寿命长.制备出兼有高能量密度的电极材料是当前超级电容器研究的重点.以提高电容储能为目标,通过掺杂N原子来调制石墨烯的电子结构,使用基于密度泛函理论的第一原理计算了不同N掺杂构型石墨烯的态密度和能带结构,拟合出了石墨烯的量子电容,分析了量子电容储能提升的原因.

Supercapacitor is an energy storage device which obtains energy from the electrochemical double layer or the redox- type reactions at or beyond the surface of the electrode, which can meet the demands for high power and long cycle life. However, the electrode still has low energy density for supercapacitor device. The design of electrode material is essential for obtaining high capacity. We employ density functional theory based on the first principle to calculate the electronic structures and derive the capacitance of N-doping graphene. We find that the quantum capacitance can be substantially improved by N doping. The physical mechanism of such phenomena is discussed in this paper.