Microwave-assisted synthesis of self-assembled camellia-like CuS superstructure of ultra-thin nanosheets and exploration of its sodium ion storage properties

Abstract

The major merit of this work is to use a facile microwave-assisted method to synthesize nanosheet-assembled camellia-like CuS material. When investigated as a novel anode for SIBs, the electrode exhibits an outstanding electrochemical performance. • A novel camellia-like CuS superstructure is first prepared by a microwave-assisted heating method. • Structural evolution is explained by the Ostwald ripening and oriented growth mechanism. • The CuS electrode shows excellent cycling stability and rate performance for SIBs. • The obtained nanosheet-assembled CuS anode delivers a large pseudocapacitive behavior. Layered copper sulfide (CuS) has immense commercial application potential in sodium-ion batteries (SIBs) due to its high capacity, diverse structures, and controllable synthetic methods. Despite these advantages, due to the large volume changes and soluble polysulfide intermediates based on the conversion reaction, it is a huge challenge for CuS electrodes to maintain high-rate performance and long-term cycle stability. Herein, a camellia-like CuS superstructure is designed and synthesized to improve cycling stability and rate performance. The cycling stability reflects in a stable capacity of 347.1 mAh g −1 can still be retained at 0.1 A g −1 after 100 cycles, and even after 1000 cycles at 5.0 A g −1 without decay. The excellent rate performance is embodied in the capacity of 352.4 and 255.7 mAh g −1 at 0.05 and 5.0 A g −1 , respectively. This work provides a feasible route to develop CuS anode material of SIBs with remarkable sodium storage performance.