Microporous Battery Electrodes from Molecular Cluster Precursors

Developing novel energy storage materials is critical to many renewable energy technologies. In this work, we report on the synthesis and electrochemical properties of materials composed of porous cobalt selenide microspheres prepared from molecular cluster precursors. The cobalt selenide microspheres excel as Na ⁺ ion battery electrode materials, with a specific capacity of ∼550 mA h/g and excellent cycling stability of 85% over 100 cycles, and perform equally well as Li ⁺ ion battery electrodes with a specific capacity of ∼600 mA h/g and cycling stability of 80% over 100 cycles. Materials which reversibly store large amounts of Na ⁺ ions are uncommon, and these performances represent significant advances in the field. More broadly, this work establishes metal chalcogenide molecular clusters as valuable precursors for creating new, tunable energy storage materials.