High rate capacity retention of binder-free, tin oxide nanowire arrays using thin titania and alumina coatings

Abstract

This paper reports the use of thin titania or alumina coatings on tin oxide nanowire arrays for high cyclability electrodes for lithium-ion batteries. We demonstrate that such coatings can significantly reduce irreversible capacity loss associated with the formation of a solid electrolyte interface and improve the capacity retention at high rates. Specifically, tin oxide nanowires grown on stainless steel substrates were conformally coated with thin films of either titania or alumina using atomic layer deposition and were tested as anodes in coin cells. Both titania and alumina coatings resulted in no initial capacity loss due to solid electrolyte interface formation in the first cycle. Tin oxide nanowire array electrodes coated with 5 nm thick titania layer and 1 nm thick alumina layer retained capacities of 767 and 725 mA h g À1 after 30 cycles using current density of 700 mA g À1 . Both electrodes retained capacity around 664 mA h g À1 after 30 cycles using a current density of 1500 mA g À1 , respectively. The results indicate that thin coatings acted as mechanical shells preserving the electrode nanostructure morphology necessary for high capacity retention. The study also showed that within the first two cycles, tin migrates out forming nanoclusters on the surface of nanowires due to both stress enhanced diffusion and the Kirkendall effect. The presence of tin nanoclusters on the surface of protective layers further enhances high rate capability.

Atomic scale structure of amorphous aluminum oxyhydroxide, oxide and oxycarbide films probed by very high field27Al nuclear magnetic resonance

“…The widespread use of alumina is intimately linked to the functional properties of its various crystallographic polymorphs (corundum, gamma alumina, etc.). 1 Recently, there has been a surge of interest for the use of alumina films as protective barriers for battery electrode materials, 2,3 for sensors, 4 as well as for corrosion and medium temperature (400-600 1C) oxidation protection. [5][6][7] Also, the optical properties of alumina films show potential for RF transparency, light polarization, and broadband and wide-angle antireflection.…”

Scalable production and applications of metal oxide nanowires.

“…The exposure time used here is less than a minute which is about 3.5 orders of magnitude faster than that using a hydrothermal method. underlying mechanism for porous structure formation seems to be similar to that suggested in many other reports using hydrothermal synthesis with additional annealing step [118]. However, the actual mechanism is not completely clear in terms of how phase transformation leads to porous nature within the nanowires.…”

“…Up to date, several approaches have been proposed to prepare tin oxide nanowires including chemical vapor deposition [115], laser ablation [116], template method [117] and most predominantly hydrothermal technique [118].…”

Visible-light photocatalytic capability and the mechanism investigation of a novel PANI/Sn3O4 p–n heterostructure

“…8 Until now, the Sn 3 O 4 band gap was reported as $2.61 eV, 53 2.75 eV, 54 2.85 eV 55 and 2.56 eV. 56 The PANI nanobers' band gap has been reported as $2.80 eV 57 by many researchers. The Tauc plots in Fig.…”