Nitrogen-Doped Seamless Activated Carbon Electrode with Excellent Durability for Electric Double Layer Capacitor
Tomomi Tagaya, Yoshikiyo Hatakeyama, Soshi Shiraishi, Hidehiko Tsukada, María José Mostazo‐López, Emilia Morallón, Diego Cazorla‐Amorós
Abstract
The electric double layer capacitor (EDLC) using a seamless activated carbon electrode shows an excellent durability against high voltage charging compared to the conventional activated carbon composite electrode. In this study, the authors focused on nitrogen-doping as a surface modification to further improve the electrochemical durability of the seamless electrode. The EDLC using the nitrogen-doped seamless activated carbon electrode achieved the volumetric capacitance of 18 F cm −3 (based on the galvanostatic method, 80 mA g −1 , 0–2.5 V, 40 °C) and the capacitance retention of 83% after the float durability test (3.5 V, 70 °C, 100 h) using a typical propylene carbonate electrolyte. The volumetric capacitance is comparable to that (14 F cm −3 ) of the conventional activated carbon, such as YP50F, and the retention is much higher than that (76%) of the pristine seamless activated carbon. The authors concluded that the extremely excellent durability of the nitrogen-doped seamless activated carbon electrode is due to (i) the stable electric network arising from the binder-less monolithic structure and (ii) nitrogen surface functionalities that suppresses micropore blocking and internal resistance change caused by electrochemical decomposition deposits. (184 words).