title: Extraordinary Performance of Carbon-Coated Anatase TiO2as Sodium-Ion Anode.
abstract: The synthesis of in situ polymer-functionalized anatase TiO2particles using an anchoring block copolymer with hydroxamate as coordinating species is reported, which yields nanoparticles (≈11 nm) in multigram scale. Thermal annealing converts the polymer brushes into a uniform and homogeneous carbon coating as proven by high resolution transmission electron microscopy and Raman spectroscopy. The strong impact of particle size as well as carbon coating on the electrochemical performance of anatase TiO2is demonstrated. Downsizing the particles leads to higher reversible uptake/release of sodium cations per formula unit TiO2(e.g., 0.72 eq. Na+(11 nm) vs only 0.56 eq. Na+(40 nm)) while the carbon coating improves rate performance. The combination of small particle size and homogeneous carbon coating allows for the excellent electrochemical performance of anatase TiO2at high (134 mAh g-1at 10 C (3.35 A g-1)) and low (≈227 mAh g-1at 0.1 C) current rates, high cycling stability (full capacity retention between 2nd and 300th cycle at 1 C) and improved coulombic efficiency (≈99.8%).
authors.affiliation: Institute for Inorganic and Analytical Chemistry University of Mainz Duesbergweg 10-14 55128 Mainz Germany.
authors.forename: Muhammad Nawaz
authors.initials: MN
authors.lastname: Tahir
authors.affiliation: Institute for Organic Chemistry University of Mainz Duesbergweg 10-14 55128 Mainz Germany; Graduate School Materials Science in Mainz Staudinger Weg 9 55128 Mainz Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Oschmann
authors.affiliation: Helmholtz Institute Ulm (HIU) Electrochemistry I Helmholtzstr. 11 89081 Ulm Germany; Karlsruhe Institute of Technology (KIT) P.O. Box 3640 76021 Karlsruhe Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Buchholz
authors.affiliation: Helmholtz Institute Ulm (HIU) Electrochemistry I Helmholtzstr. 11 89081 Ulm Germany; Karlsruhe Institute of Technology (KIT) P.O. Box 3640 76021 Karlsruhe Germany.
authors.forename: Xinwei
authors.initials: X
authors.lastname: Dou
authors.affiliation: Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Lieberwirth
authors.affiliation: Institute for Inorganic and Analytical Chemistry University of Mainz Duesbergweg 10-14 55128 Mainz Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Panthöfer
authors.affiliation: Institute for Inorganic and Analytical Chemistry University of Mainz Duesbergweg 10-14 55128 Mainz Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Tremel
authors.affiliation: Institute for Organic Chemistry University of Mainz Duesbergweg 10-14 55128 Mainz Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Zentel
authors.affiliation: Helmholtz Institute Ulm (HIU) Electrochemistry I Helmholtzstr. 11 89081 Ulm Germany; Karlsruhe Institute of Technology (KIT) P.O. Box 3640 76021 Karlsruhe Germany.
authors.forename: Stefano
authors.initials: S
authors.lastname: Passerini
keywords: RAFT polymerization; anatase TiO2; carbon coating; nanoparticles; sodium‐ion batteries