In this work, we present a new approach of converting vibration energy to electric energy using porous graphene oxide-nickel (pGO-Ni) electrode and ionic solution. When actuated by vibration, the ionic solution repeatedly flows across the pGO-Ni electrode which changes the electric double layer at the interface between the pGO-Ni electrode and ionic solution. Therefore, a significant potential difference between the working electrode and the reference electrode immersed into the static ionic solution is observed. The output voltage first increases with the vibration frequency and then gradually approaches to a saturated value of 70.12 mV as the vibration frequency increases to 15 Hz. By connecting a 3 K Omega resistance to the energy conversion system, the discharging behaviors of the energy conversion system are studied, which shows an exponential decay of the output voltage and current. The proposed energy conversion system is analogous to a supercapacitor, whose effective capacitance, internal resistance and energy conversion efficiency are deduced based on the discharging experiments. The work provides a new vibration-to-electric energy conversion mechanism, which may inspire potential applications in flow sensor and harvesting waste mechanical or vibration energy. (C) 2017 Elsevier B.V.All rights reserved.