Unraveling the Impact of Ether and Carbonate Electrolytes on the Solid-Electrolyte Interface and the Electrochemical Performances of ZnSe@C Core-Shell Composite as Anode of Lithium Ion Batteries.

The recognition of solid electrolyte interface (SEI) between the electrode materials and electrolyte is limiting the selection of electrode materials, electrolytes and further the electrochemical performance of batteries. Herein, we report ZnSe@C core-shell nanocomposites derived from ZIF-8 as anode materials of lithium ion batteries (LIBs), the electrochemical performances and SEI films formed on ZnSe@C in both ether and carbonate electrolytes. It is found that ZnSe@C delivers a reversible capacity of 617.1 mAh·g-1 after 800 cycles at 1 A·g-1 in ether electrolyte, much higher than that in carbonate electrolyte. Both ex-situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) reveal that stable SEI films are formed on ZnSe@C in ether electrolyte while selenium is involved in the formation of SEI film and further dissolved into carbonate electrolyte due to the concurrent decomposition of electrolyte and insertion of Li+ into ZnSe, which differentiates between the cycling performances of ZnSe@C composite in ether and carbonate electrolyte.