Designing MOFs-Derived FeS2@Carbon Composites for High-Rate Sodium Ion Storage with Capacitive Contributions

Abstract

Sodium-ion batteries suffer the disadvantages of poor rate performance and cycling stability due to its sluggish sodiation kinetics. A rational design strategy for both materials compositions and structures has been proposed to meet these challenges. Herein, a triple-component composite derived from metal–organic frameworks, comprising FeS2, nitrogen–sulfur co-doped porous carbon, and reduced graphene oxide (FeS2@NSC/G), has been successfully synthesized. With the capacities contributions from different sodium storage routes (diffusion-controlled processes and surface capacitive processes) at varies rate conditions, it is aiming to make full use of each component in the electrode composite and their unique porous structures. Expected electrode properties have been achieved and related electrochemical behaviors have also been investigated. The strategy would present a promising thought for composites design, which could enhance high-rate electrochemical energy storage performances.