Ultra-small RuO2 nanoparticles supported on carbon cloth as a high-performance pseudocapacitive electrode

RuO 2 has been extensively investigated as a pseudocapacitive material. However, developing a facile and effective method to improve the pseudocapacitive performance of RuO 2 is still desired. In this work, we report the synthesis of ultra-small RuO 2 nanoparticles supported on carbon cloth (us-RuO 2 /CC) via a facile two-step method. As a binder-free electrode, us-RuO 2 /CC exhibits a high capacitance of 1067.4 F g −1 at a current density of 1 A g −1 . Moreover, us-RuO 2 /CC also shows good rate performance (87.8% capacitance retention at 20 A g −1 ) and cycle stability (99.6% capacitance retention after 5000 cycles). Graphical abstract Ultra-small RuO 2 nanoparticles on carbon cloth (us-RuO 2 /CC) were synthesized via annealing and acid etching treatment of a ZnRu precursor, which was prepared by a dip-coating process. Introducing Zn significantly reduces the particle size of RuO 2 , leading to a high specific capacitance of 1067.4 F g −1 .