Nanoporous CuAg bimetal/manganese dioxide (NP-CuAg/MnO₂) composites as electrode materials have been successfully synthesized by chemically depositing manganese dioxide (MnO₂) on nanoporous CuAg bimetal (NP-CuAg). NP-CuAg can be produced by chemical dealloying the Cu-Zr-Ag metallic glasses. The phases and microstructures of NP-CuAg and NP-CuAg/MnO₂ composite materials were examined by XRD and SEM. The electrochemical properties of the NP-CuAg/MnO₂ composite electrode materials were investigated by cyclic voltammetry and galvanostatic charge-discharge measurements. For the NP-CuAg-supported MnO₂ composites, the MnO₂ nanoflakes are deposited on the surface of the NP-CuAg substrate. Owing to the three dimensional continuous nanoporous structure and excellent electrical conductivity of NP-CuAg, the MnO₂ nanoflakes can produce much larger surface area as compared to its aggregate particles. Moreover, the NP-CuAg/MnO₂ composite materials exhibit higher electrical conductivity than the NPC/MnO₂ composite materials. Thus, the utilization of MnO₂ surface active sites is improved, which leads to the higher specific capacitance. The specific capacitance increases with the increase of the Ag content in the precursor alloy. Cu₄₅Zr₄₅Ag₁₀ ribbon after dealloying in 0.1 M HF for 10 h, the specific capacitance reaches to 392.86 F/g. The button type energy storage device encapsulated by the NP-CuAg/MnO₂ composite electrode materials, is able to light on the LED.