A research group led by Prof. SUN Gongquan and Prof. WANG Suli from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences invented a new electrochemical power sources based on the in-situ coupling of direct methanol fuel cells and supercapacitors. Their findings were published in ACS Energy Letters.
Diagram of the hybrid electric power device (HEPD) and the comparison of the specific energy and power for the direct methanol fuel cells (DMFC) and HEPD. (Image by XIA Zhangxun)
High power density and high energy density are the key issues for the development of electrochemical power sources to meet the growing demands from a wide range of applications. However, most of the traditional power sources can hardly possess both features.
The commercialization of fuel cells is hampered by the relatively low specific power density, even though the energy density of fuel cells is great. On the other hand, the wide application of devices with high power density, such as supercapacitors, is also limited by the insufficient specific energy density. Hence, to develop alternative power sources with both high power and energy density is of great important for future energy researches and applications.
Based on previous studies on the key electrode materials, direct alcohol fuel cells and supercapacitors, the scientists for the first time coupled the voltage-sensitive PANI with the catalyst layers of direct methanol fuel cells (DMFCs).
As a result, the self-charging processes were achieved on the pseudo-capacitor of PANI. The ultra-fast discharging processes of PANI remarkably increased the pulse discharge current density of the hybrid power devices, whereas the constant methanol fuel feeding guaranteed the high energy density of the system.
This work sheds lights on the development of the next generation power sources for portable and vehicle applications.
The study was supported by National Key Research Project of the National Natural Science Foundation of China. (Text by XIA Zhangxun)