title: Synthesizing Porous NaTi2(PO4)3 Nanoparticles Embedded in 3D Graphene Networks for High-Rate and Long Cycle-Life Sodium Electrodes.
abstract: 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(-1) at 1C, 105 mAh g(-1) at 5C, 96 mAh g(-1) at 10C, 67 mAh g(-1) 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.
authors.affiliation: ‡Max Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany.
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
authors.affiliation: ‡Max Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Kopold
authors.affiliation: ‡Max Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany.
authors.forename: Yuan-Li
authors.initials: YL
authors.lastname: Ding
authors.affiliation: ‡Max Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany.
authors.forename: Peter A
authors.initials: PA
authors.lastname: van Aken
authors.affiliation: ‡Max Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Maier
authors.affiliation: †Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China.|‡Max Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart 70569, Germany.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
keywords: 3D graphene-network; NaTi2(PO4)3; long-cycle life; mesoporous nanoparticles; ultrafast sodium storage