A New Salt‐Baked Approach for Confining Selenium in Metal Complex‐Derived Porous Carbon with Superior Lithium Storage Properties

Abstract

For lithium‐selenium batteries, commercial applications are hindered by the inferior electrical conductivity of selenium and the low utilization ratio of the active selenium. Here, we report a new baked‐in‐salt approach to enable Se to better infiltrate into metal‐complex‐derived porous carbon (Se/MnMC‐B). The approach uses the confined, narrow space that is sandwiched between two compact NaCl solid disks, thus avoiding the need for protection with argon or a vacuum environment during processing. The electrochemical properties for both lithium and sodium storage of our Se/MnMC‐B cathode were found to be outstanding. For lithium storage, the Se/MnMC‐B cathode (with 72% selenium loading) exhibited a capacity of 580 mA h g −1 after 1000 cycles at 1 C, and an excellent rate capability was achieved at 20 C and 510 mA h g −1 . For sodium storage, a specific capacity of 535 mA h g −1 was achieved at 0.1 C after 150 cycles. These results demonstrate the potential of this approach as a new effective general synthesis method for confining other low melting point materials into a porous carbon matrix.