Bullet-like Cu9 S5 Hollow Particles Coated with Nitrogen-Doped Carbon for Sodium-Ion Batteries.

Metal sulfides with excellent redox reversibility and high capacity are very promising electrode materials for sodium-ion batteries. However, their practical application is still hindered by the poor rate capability and limited cycle life. Herein, a template-based strategy is developed to synthesize nitrogen-doped carbon-coated Cu9 S5 bullet-like hollow particles starting from bullet-like ZnO particles. With the structural and compositional advantages, these unique nitrogen-doped carbon-coated Cu9 S5 bullet-like hollow particles manifest excellent sodium storage properties with superior rate capability and ultra-stable cycling performance.