Realizing Rapid Kinetics of Na Ions in Tin‐Antimony Bimetallic Sulfide Anode with Engineered Porous Structure

Abstract

Metallic sulfide anodes show great promise for sodium‐ion batteries due to their high theoretic capacities. However, their practical application is greatly hampered by poor electrochemical performance because of the large volume expansion of the sulfides and the sluggish kinetics of the Na+ ions. Herein, a porous bimetallic sulfide of the SnS/Sb2S3 heterostructure is constructed that is encapsulated in the sulfur and nitrogen codoped carbon matrix (SnS/Sb2S3@SNC) by a facile and scalable method. The porous structure can provide void space to alleviate the volume expansion upon cycling, guaranteeing excellent structural stability. The unique heterostructure and the S, N codoped carbon matrix together facilitate fast‐charge transport to improve reaction kinetics. Benefitting from these merits, the SnS/Sb2S3@SNC electrode exhibits high capacities of 425 mA h g−1 at 200 mA g−1 after 100 cycles, and 302 mA h g−1 at 500 mA g−1 after 400 cycles. Moreover, the SnS/Sb2S3@SNC anode shows an outstanding rate performance with a capacity of over 200 mA h g−1 at a high current density of 5000 mA g−1. This study provides a new strategy and insight into the design of electrode materials with the potential for the practical realization and applications of next‐generation batteries.

Keywords

• carbon
• heterostructures
• metallic sulfides
• porous structures
• sodium-ion batteries