We reported an ultra low-power resistive random access memory (RRAM) combining a low-cost Ni electrode and covalent-bond GeO x dielectric. This cost-effective Ni/GeO x /TaN RRAM device has very small set power of 2μW, ultra-low reset power of 130pW, greater than 1 order of magnitude resistance window, and stable retention at 85°C. The current flow at low-resistance state is governed by Poole–Frenkel conduction with electrons hopping via defect traps, which is quite different from the filament conduction in metal-oxide RRAM.