Synthesizing Porous NaTi2(PO4)3 Nanoparticles Embedded in 3D Graphene Networks for High-Rate and Long Cycle-Life Sodium Electrodes

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• 作者：Chao Wu ; Peter Kopold ; Yuan-Li Ding ; Peter A. van Aken ; Joachim Maier ; Yan Yu
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：June 23, 2015
• 年：2015
• 卷：9
• 期：6
• 页码：6610-6618
• 全文大小：829K
• ISSN：1936-086X

文摘

Sodium ion batteries attract increasing attention for large-scale energy storage as a promising alternative to the lithium counterparts in view of low cost and abundant sodium source. However, the large ion radius of Na brings about a series of challenging thermodynamic and kinetic difficulties to the electrodes for sodium-storage, including low reversible capacity and low ion transport, as well as large volume change. To mitigate or even overcome the kinetic problems, we develop a self-assembly route to a novel architecture consisting of nanosized porous NASICON-type NaTi₂(PO₄)₃ particles embedded in microsized 3D graphene network. Such architecture synergistically combines the advantages of a 3D graphene network and of 0D porous nanoparticles. It greatly increases the electron/ion transport kinetics and assures the electrode structure integrity, leading to attractive electrochemical performance as reflected by a high rate-capability (112 mAh g^鈥? at 1C, 105 mAh g^鈥? at 5C, 96 mAh g^鈥? at 10C, 67 mAh g^鈥? at 50C), a long cycle-life (capacity retention of 80% after 1000 cycles at 10C), and a high initial Coulombic efficiency (>79%). This nanostructure design provides a promising pathway for developing high performance NASICON-type materials for sodium storage.