The Bright Future for Electrode Materials of Energy Devices: Highly Conductive Porous Na-Embedded Carbon

High electrical conductivity and large accessible surface area, which are required for ideal electrode materials of energy conversion and storage devices, are opposed to each other in current materials. It is a long-term goal to solve this issue. Herein, we report highly conductive porous Na-embedded carbon (Na@C) nanowalls with large surface areas, which have been synthesized by an invented reaction of CO with liquid Na. Their electrical conductivities are 2 orders of magnitude larger than highly conductive 3D graphene. Furthermore, almost all their surface areas are accessible for electrolyte ions. These unique properties make them ideal electrode materials for energy devices, which significantly surpass expensive Pt. Consequently, the dye-sensitized solar cells (DSSCs) with the Na@C counter electrode has reached a high power conversion efficiency of 11.03%. The Na@C also exhibited excellent performance for supercapacitors, leading to high capacitance of 145 F g^-1 at current density of 1 A g^-1.