Novel Potassium-Ion Hybrid Capacitor Based on an Anode of K2Ti6O13 Microscaffolds

作者：Dong, Shengyang; Li, Zhifei; Xing, Zhenyu; Wu, Xianyong; Ji, Xiulei^*; Zhang, Xiaogang^*

来源：ACS Applied Materials & Interfaces, 2018, 10(18): 15542-15547.

DOI：10.1021/acsami.7b15314

• energy storage
• hybrid capacitor
• potassium-ion intercalation
• K2Ti6O13
• nanoporous graphenic carbon

To fill the gap between batteries and supercapacitors requires integration of the following features in a single system: energy density well above that of supercapacitors, cycle life much longer than Li-ion batteries, and low cost. Along this line, we report a novel nonaqueous potassium-ion hybrid capacitor (KIC) that employs an anode of K2Ti6O13 (KTO) microscaffolds constructed by nanorods and a cathode of N-doped nanoporous graphenic carbon (NGC). K2Ti6O13 microscaffolds are studied for potential applications as the anode material in potassium-ion storage for the first time. This material exhibits an excellent capacity retention of 85% after 1000 cycles. In addition, the NGC//KTO KIC delivers a high energy density of 58.2 Wh kg(-1) based on the active mass in both electrodes, high power density of 7200 W kg(-1), and outstanding cycling stability over 5000 cycles. The usage of K ions as the anode charge carrier instead of Li ions and the amenable performance of this device suggest that hybrid capacitor devices may welcome a new era of beyond lithium.

• 出版日期2018-5-9
• 单位南京航空航天大学