Embedding ZnSe nanoparticles in a porous nitrogen-doped carbon framework for efficient sodium storage

Abstract

Sodium-ion batteries (SIBs) have drawn great attentions due to the abundance of sodium and their similar electrochemical principles to that of lithium-ion batteries. However, larger ionic radius of Na+ greatly retards Na+ transport and causes severe volume expansion. Therefore, delicate design of anodes for SIBs that can reversibly accommodate sodium ions is a crucial, but challenging task. In this paper, we rationally engineer a hybrid composite featured with ZnSe nanoparticles uniformly wrapped in three-dimensional (3D) porous nitrogen-doped carbon matrix (ZnSe NP@p-NC). The synthesis is achieved through the domination of the self-template-induced reaction between Zn-based zeolitic imidazolate framework (ZIF-8) nanododecahedra and Se powder at an elevated temperature. Due to the structural and compositional merits, including a 3D porous structure, the uniform distribution of the small-size ZnSe nanoparticles, and graphitic carbon matrix, these unique ZnSe NP@p-NC popcorn balls display a high sodium-storage performance, including cycling stability (181.7 mAh g−1 after 2000 cycles at 10 A g−1), rate capability, and initial Coulombic efficiency.