title: Combining Optimized Particle Morphology with a Niobium-Based Coating for Long Cycling-Life, High-Voltage Lithium-Ion Batteries.
abstract: Morphologically optimized LiNi0.5 Mn1.5 O4 (LMNO-0) particles were treated with LiNbO3 to prepare a homogeneously coated material (LMNO-Nb) as cathode in batteries. Graphite/LMNO-Nb full cells present a twofold higher cycling life than cells assembled using uncoated LMNO-0 (graphite/LMNO-0 cell): Graphite/LMNO-0 cells achieve 80 % of the initial capacity after more than 300 cycles whereas for graphite/LMNO-Nb cells this is the case for more than 600 cycles. Impedance spectroscopy measurements reveal significantly lower film and charge-transfer resistances for graphite/LMNO-Nb cells than for graphite/LMNO-0 cells during cycling. Reduced resistances suggest slower aging related to film thickening and increase of charge-transfer resistances when using LMNO-Nb cathodes. Tests at 45 °C confirm the good electrochemical performance of the investigated graphite/LMNO cells while the cycling stability of full cells is considerably lowered under these conditions.
authors.affiliation: Accumulators Materials Research, Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), Helmholtzstraße 8, 89081, Ulm, Germany. giulio.gabrielli@zsw-bw.de.
authors.forename: Giulio
authors.initials: G
authors.lastname: Gabrielli
authors.affiliation: Accumulators Materials Research, Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), Helmholtzstraße 8, 89081, Ulm, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Axmann
authors.affiliation: Institute of Surface Chemistry and Catalysis, Ulm University, Albert-Einstein-Allee 47, 89081, Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Diemant
authors.affiliation: Institute of Surface Chemistry and Catalysis, Ulm University, Albert-Einstein-Allee 47, 89081, Ulm, Germany.
authors.forename: Rolf Jürgen
authors.initials: RJ
authors.lastname: Behm
authors.affiliation: Accumulators Materials Research, Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), Helmholtzstraße 8, 89081, Ulm, Germany.
authors.forename: Margret
authors.initials: M
authors.lastname: Wohlfahrt-Mehrens
mesh_terms: D011211:Electric Power Supplies; D004563:Electrochemistry; D006108:Graphite / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry
chemical_list: D010087:Oxides; D009556:Niobium; D006108:Graphite; D008094:Lithium
keywords: batteries; coatings; high-voltage cathode; lithium; spinel phase