6533b85dfe1ef96bd12be987

RESEARCH PRODUCT

Extraordinary Performance of Carbon‐Coated Anatase TiO 2 as Sodium‐Ion Anode

Xinwei DouDaniel BuchholzBernd OschmannWolfgang TremelStefano PasseriniMartin PanthöferIngo LieberwirthMuhammed Nawaz TahirRudolf Zentel

subject

sodium‐ion batteriesAnataseMaterials scienceInorganic chemistryNanoparticle02 engineering and technology010402 general chemistryElectrochemistry7. Clean energy01 natural sciencessymbols.namesakeGeneral Materials ScienceHigh-resolution transmission electron microscopyRAFT polymerizationFull PaperRenewable Energy Sustainability and the EnvironmentFull Papers021001 nanoscience & nanotechnology0104 chemical sciencesAnodeanatase TiO2carbon coatingChemical engineeringsymbolsnanoparticlesParticle size0210 nano-technologyRaman spectroscopyFaraday efficiency

description

The synthesis of in situ polymer‐functionalized anatase TiO2 particles 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 TiO2 is 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 TiO2 at high (134 mAh g−1 at 10 C (3.35 A g−1)) and low (≈227 mAh g−1 at 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%).

yearjournalcountryeditionlanguage
2015-12-01Advanced Energy Materials
https://doi.org/10.1002/aenm.201501489