Platelet-like CuS impregnated with twin crystal structures for high performance sodium-ion storage

Metal sulfides with high capacity have been considered as candidates for efficient sodium-ion storage. However, their undesirable rate capability and fast capacity fading hinder their commercial applications. Herein, we prepared a platelet-like CuS material with twin crystals. The edges of the platelet are composed of single crystal structures, and the interior of platelet contains twin crystal structures. Due to its structural and compositional advantages, this platelet-like CuS material with twin crystal structures manifests superior rate performance (420 mA h g(-1) at 0.05 A g(-1) and 277 mA h g(-1) at 5 A g(-1)) and excellent cycling stability without capacity decay after around 500 cycles at 2 A g(-1).