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Zhu on Cover of Advanced Functional Materials

October 25, 2017

MIE Assistant Professor Hongli Zhu's research on "Batteries: Freestanding Metallic 1T MoS2 with Dual Ion Diffusion Paths as High Rate Anode for Sodium-Ion Batteries" was featured on the cover of Advanced Functional Materials.

Sodium is earth abundant and readily accessible, and the low toxicity improves safety during transport and storage as well as alleviates environmental concerns. Sodium ion batteries, similar in fundamental electrochemistry but differing in intercalation behavior to lithium ion batteries, are a highly promising option for use in the next generation of large scale energy storage.

Until now, only semiconducting 2H phase MoS2 has been investigated as an anode for sodium ion batteries. Our work creates a new, effective method for directly chemical synthesis of metallic 1T MoS2 on three dimensional hollow graphene foam that results in a freestanding and lightweight nanostructure with the high mass loading of active material. We demonstrate for the first time the use of metallic 1T MoS2 as an intercalation anode for sodium ion batteries. The 1T MoS2 grows on both the internal and external walls of each graphene tube to form a freestanding MoS2-graphene-MoS2 sandwich electrode. The porous, hollow structure of the electrode allows maximum electrolyte accessibility and the graphene backbone provides excellent electrical conductivity. The MoS2-graphene-MoS2 structure exhibits excellent electrochemical performance: a high reversible capacity of 313 mAh/g is obtained at a current density of 0.05 A/g for 200 cycles, and a high rate capability of 175 mAh/g is observed at 2 A/g.

In this work, three-dimensional hollow Metallic MoS2-graphene-MoS2 sandwich electrode is constructed successfully. The MoS2-graphene-MoS2 electrode exhibit excellent electrochemical performance. The freestanding, lightweight, porous, hollow metallic MoS2-graphene-MoS2 sandwich electrode highly facilitates electron/ion transportation during the charge/discharge for high performance sodium ion batteries.