Nano-fluids with KH550-grafted TiO2 nano-particles homogenously dispersed into propylene carbonate exhibit substantially enhanced dielectric properties compared with the base liquid. Specifically, the breakdown stability of nano-fluids is dramatically improved for a small high-voltage electrode potential increasing rate, which has a potential to increase the reliability of the pulsed power system. On the other hand, the mean breakdown voltage of nano-fluids is more than 30% larger than that of base liquid when the high-voltage electrode potential increasing rate equals to 6 kV/mu s, which will lead to a great increase in energy storage density of the pulsed power system. (C) 2016 Elsevier B.V. All rights reserved.