Co/Zn-metal organic frameworks derived functional matrix for highly active amorphous Se stabilization and advanced lithium storage

Lithium–selenium batteries, as an advanced rechargeable battery system, have attracted wide attention. However, its application is hurdled by the ambiguous underlying mechanism such as the unclear active phase and the key role of the host materials. Herein, a three-dimensional (3D) functional matrix derived from the Co/Zn-metal organic framework is synthesized to unravel the questions raised. It reveals that the strong interaction and voids in the 3D matrix serve to anchor the amorphous Se with high electrochemical properties. The obtained 3DC/Se exhibits 544.2 and 273.2 mAh·g⁻¹ at current densities of 0.1C and 2.0C, respectively, with a diffusion-controlled mechanism. The excessive amount of Se beyond the loading capacity of the matrix leads to the formation of trigonal phase Se, which shows an unsatisfying electrochemical property. Graphical abstract: [Figure not available: see fulltext.].