 Organized structures have shown significant improvements in the electrochemical performance of rechargeable batteries. In this research, we investigated three-dimensionally connected open-porous aluminum alloy (AlSi12) as substrate coated with SiO2 nanoparticles as potential electrode in a Li-ion battery. Effects and morphological characteristics of such structure were investigated through electrochemical experiments. Results showed that the electrode performance was influenced by the pore size of the substrate. When the electrode pore size was decreased from 3000 to 2000 µm, there was a decrease of 140% in the electrode-specific capacity. Comparing with the reference sample that has no pores, the specific capacity can be increased by at least a factor of two when pores are introduced. This is due to the transition from the non-Faradic current in the non-porous non-coated electrode to the Faradic current in the porous coated electrode. This finding opens the potential for future study in kinetics of electrochemical reactions in open-pored hierarchical structures.