Micropore‐Rich Yolk‐Shell N‐doped Carbon Spheres: An Ideal Electrode Material for High‐Energy Capacitive Energy Storage
Xinyuan Li, Zhenhui Liu, Congcong Cai, Qiang Yu, Wenting Jin, Ming Xu, Yu Chang, Shidong Li, Liang Zhou, Liqiang Mai
Abstract
Abstract Increasing the energy density of electrochemical double layer capacitors (EDLCs) can broaden their applications in energy storage but remains a formidable challenge. Herein, micropore‐rich yolk‐shell structured N‐doped carbon spheres (YSNCSs) were constructed by a one‐pot surfactant‐free self‐assembly method in aqueous solution. The resultant YSNCSs after activation possessed an ultrahigh surface area of 2536 m 2 g −1 , among which 80 % was contributed from micropores. When applied in EDLCs, the activated YSNCSs demonstrated an unprecedentedly high capacitance (270 F g −1 at 1 A g −1 ) in 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([EMIM][BF 4 ]) ionic liquid, affording an ultrahigh energy density (133 Wh kg −1 at 943 W kg −1 ). The present contribution provides insight into engineering porous carbons for capacitive energy storage.