Expeditious Electrochemical Synthesis of Mesoporous Chalcogenide Flakes: Mesoporous Cu2 Se as a Potential High-Rate Anode for Sodium-Ion Battery

Small. 2022 Aug;18(34):e2106629. doi: 10.1002/smll.202106629. Epub 2022 Jul 29.

Abstract

Nanostructured copper selenide (Cu2 Se) attracts much interest as it shows outstanding performance as thermoelectric, photo-thermal, and optical material. The mesoporous structure is also a promising morphology to obtain better performance for electrochemical and catalytic applications, thanks to its high surface area. A simple one-step electrochemical method is proposed for mesoporous chalcogenides synthesis. The synthesized Cu2 Se material has two types of mesopores (9 and 18 nm in diameter), which are uniformly distributed inside the flakes. These materials are also implemented for sodium (Na) ion battery (NIB) anode as a proof of concept. The electrode employing the mesoporous Cu2 Se exhibits superior and more stable specific capacity as a NIB anode compared to the non-porous samples. The electrode also exhibits excellent rate tolerance at each current density, from 100 to 1000 mA g-1 . It is suggested that the mesoporous structure is advantageous for the insertion of Na ions inside the flakes. Electrochemical analysis indicates that the mesoporous electrode possesses more prominent diffusion-controlled kinetics during the sodiation-desodiation process, which contributes to the improvement of Na-ion storage performance.

Keywords: Na-ion batteries; block copolymers; electrochemical deposition; mesoporous semiconductors; self-assembly.