Controlled Synthesis of Ultrafine β-Mo₂C Nanoparticles Encapsulated in N-Doped Porous Carbon for Boosting Lithium Storage Kinetics

Abstract

Rational construction of anode material architecture to afford excellent cycling stability, fast rate capacity, and large specific capacity is essential to promote further development of lithium-ion batteries in commercial applications. In this work, we propose a facile strategy to anchor ultrafine β-Mo₂C nanoparticles in N-doped porous carbon skeleton (β-Mo₂C@NC) using a scalable salt-template method. The well-defined and abundant hierarchical porous structure of β-Mo₂C@NC can not only significantly enhance the electron/ion transfer but also markedly increase the specific surface area to effectively expose the electrochemically accessible active sites. Besides, the N-doped carbon matrix can turn the d-orbital electrons of the Mo to boost the electron transportation as well as distribute active sites to buffer the volume change of Mo₂C and provide conductive pathways during discharge/charge cycles. As a result, the as-prepared β-Mo₂C@NC displays excellent lithium storage performance in terms of 1701.6 mA h g^-1 at 0.1 A g^-1 after 100 cycles and a large capacity of 816.47 mA h g^-1 at 2.0 A g^-1 after 500 cycles. The above results distinctly demonstrate that the β-Mo₂C@NC composite has potential application as anode materials in high-performance energy storage devices.