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Monodisperse colloidal gallium nanoparticles: synthesis, low temperature crystallization, surface plasmon resonance and Li-ion storage.

Yarema M, Wörle M, Rossell MD, Erni R, Caputo R, Protesescu L, Kravchyk KV, Dirin DN, Lienau K, von Rohr F, Schilling A, Nachtegaal M, Kovalenko MV - J. Am. Chem. Soc. (2014)

Bottom Line: The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140-145 and 240-250 K, respectively.We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions.We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g(-1), 50% higher than those achieved for bulk Ga under identical testing conditions.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich , CH-8093 Zürich, Switzerland.

ABSTRACT
We report a facile colloidal synthesis of gallium (Ga) nanoparticles with the mean size tunable in the range of 12-46 nm and with excellent size distribution as small as 7-8%. When stored under ambient conditions, Ga nanoparticles remain stable for months due to the formation of native and passivating Ga-oxide layer (2-3 nm). The mechanism of Ga nanoparticles formation is elucidated using nuclear magnetic resonance spectroscopy and with molecular dynamics simulations. Size-dependent crystallization and melting of Ga nanoparticles in the temperature range of 98-298 K are studied with X-ray powder diffraction, specific heat measurements, transmission electron microscopy, and X-ray absorption spectroscopy. The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140-145 and 240-250 K, respectively. We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions. We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g(-1), 50% higher than those achieved for bulk Ga under identical testing conditions.

No MeSH data available.


Related in: MedlinePlus

Electrochemical performance of ∼20 nm Ga NPs andof bulkGa as anode materials for Li-ion batteries. Two-electrode half-cellswith metallic Li as counter electrode were assembled. (A) Galvanostaticecharge/discharge curves; (B) cycling stability tests; (C) rate-capabilitytests (0.5–20C rates, where 1C is a current density of 769mA g–1 based on the theoretical capacity of pureGa). All batteries were cycled in the voltage window of 0.02–1.5V.
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fig8: Electrochemical performance of ∼20 nm Ga NPs andof bulkGa as anode materials for Li-ion batteries. Two-electrode half-cellswith metallic Li as counter electrode were assembled. (A) Galvanostaticecharge/discharge curves; (B) cycling stability tests; (C) rate-capabilitytests (0.5–20C rates, where 1C is a current density of 769mA g–1 based on the theoretical capacity of pureGa). All batteries were cycled in the voltage window of 0.02–1.5V.

Mentions: Materialsforming alloys with Li, most commonly Si, Ge, Sn and Sb,32 are actively researched as alternatives to carbon-basedanodes for rechargeable Li-ion batteries due to their 2–10-foldhigher charge storage capacities as compared to commercial Graphiteanodes (capacity of 372 mAh g–1). Upon full lithiationall high-capacity Li alloys undergo a huge increase in volume by 100–300%,making bulk/microcrystalline materials fully impractical due to fastpulverization of electrodes. Nanostructuring of the active material,by producing nanowires, NPs, and nanocrystals (NCs), has proven tobe very efficient for mitigating the effects of volumetric changesand for enhancing the kinetics of the alloying reactions.33 Ga can host 2 Li atoms per Ga atom upon fulllithiation, and through the formation of Li2Ga alloy deliversa high theoretical gravimetric capacity of 769 mAh g–1. Capacities of 200–400 mAh g–1 were previouslyobtained in LiGa alloys,34 CuGa alloys,35 and Ga droplets confined in carbon matrix.36 In this study, we examined colloidal Ga NPsas an anode material for Li-ion batteries and compared the resultsto bulk Ga, tested under identical conditions (Figure 8). Prior to the electrochemical measurements, insulating long-chainedcapping ligands were removed by treating with 1 M solution of hydrazinein acetonitrile. All electrodes were measured vs metallic lithiumin half-cells and contained 64 wt % of active material, carboxymethylcellulose(CMC, 15 wt %) as a polymer binder and amorphous carbon as a conductiveadditive (21%). The films were casted from aqueous slurries, and aftervacuum drying had similar mass loading of ∼0.5 mg/cm2. Fluoroethylenecarbonate (FEC) was used as electrolyte additivefor stabilizing the solid–electrolyte interface (SEI).33b


Monodisperse colloidal gallium nanoparticles: synthesis, low temperature crystallization, surface plasmon resonance and Li-ion storage.

Yarema M, Wörle M, Rossell MD, Erni R, Caputo R, Protesescu L, Kravchyk KV, Dirin DN, Lienau K, von Rohr F, Schilling A, Nachtegaal M, Kovalenko MV - J. Am. Chem. Soc. (2014)

Electrochemical performance of ∼20 nm Ga NPs andof bulkGa as anode materials for Li-ion batteries. Two-electrode half-cellswith metallic Li as counter electrode were assembled. (A) Galvanostaticecharge/discharge curves; (B) cycling stability tests; (C) rate-capabilitytests (0.5–20C rates, where 1C is a current density of 769mA g–1 based on the theoretical capacity of pureGa). All batteries were cycled in the voltage window of 0.02–1.5V.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525770&req=5

fig8: Electrochemical performance of ∼20 nm Ga NPs andof bulkGa as anode materials for Li-ion batteries. Two-electrode half-cellswith metallic Li as counter electrode were assembled. (A) Galvanostaticecharge/discharge curves; (B) cycling stability tests; (C) rate-capabilitytests (0.5–20C rates, where 1C is a current density of 769mA g–1 based on the theoretical capacity of pureGa). All batteries were cycled in the voltage window of 0.02–1.5V.
Mentions: Materialsforming alloys with Li, most commonly Si, Ge, Sn and Sb,32 are actively researched as alternatives to carbon-basedanodes for rechargeable Li-ion batteries due to their 2–10-foldhigher charge storage capacities as compared to commercial Graphiteanodes (capacity of 372 mAh g–1). Upon full lithiationall high-capacity Li alloys undergo a huge increase in volume by 100–300%,making bulk/microcrystalline materials fully impractical due to fastpulverization of electrodes. Nanostructuring of the active material,by producing nanowires, NPs, and nanocrystals (NCs), has proven tobe very efficient for mitigating the effects of volumetric changesand for enhancing the kinetics of the alloying reactions.33 Ga can host 2 Li atoms per Ga atom upon fulllithiation, and through the formation of Li2Ga alloy deliversa high theoretical gravimetric capacity of 769 mAh g–1. Capacities of 200–400 mAh g–1 were previouslyobtained in LiGa alloys,34 CuGa alloys,35 and Ga droplets confined in carbon matrix.36 In this study, we examined colloidal Ga NPsas an anode material for Li-ion batteries and compared the resultsto bulk Ga, tested under identical conditions (Figure 8). Prior to the electrochemical measurements, insulating long-chainedcapping ligands were removed by treating with 1 M solution of hydrazinein acetonitrile. All electrodes were measured vs metallic lithiumin half-cells and contained 64 wt % of active material, carboxymethylcellulose(CMC, 15 wt %) as a polymer binder and amorphous carbon as a conductiveadditive (21%). The films were casted from aqueous slurries, and aftervacuum drying had similar mass loading of ∼0.5 mg/cm2. Fluoroethylenecarbonate (FEC) was used as electrolyte additivefor stabilizing the solid–electrolyte interface (SEI).33b

Bottom Line: The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140-145 and 240-250 K, respectively.We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions.We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g(-1), 50% higher than those achieved for bulk Ga under identical testing conditions.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich , CH-8093 Zürich, Switzerland.

ABSTRACT
We report a facile colloidal synthesis of gallium (Ga) nanoparticles with the mean size tunable in the range of 12-46 nm and with excellent size distribution as small as 7-8%. When stored under ambient conditions, Ga nanoparticles remain stable for months due to the formation of native and passivating Ga-oxide layer (2-3 nm). The mechanism of Ga nanoparticles formation is elucidated using nuclear magnetic resonance spectroscopy and with molecular dynamics simulations. Size-dependent crystallization and melting of Ga nanoparticles in the temperature range of 98-298 K are studied with X-ray powder diffraction, specific heat measurements, transmission electron microscopy, and X-ray absorption spectroscopy. The results point to delta (δ)-Ga polymorph as a single low-temperature phase, while phase transition is characterized by the large hysteresis and by the large undercooling of crystallization and melting points down to 140-145 and 240-250 K, respectively. We have observed size-tunable plasmon resonance in the ultraviolet and visible spectral regions. We also report stable operation of Ga nanoparticles as anode material for Li-ion batteries with storage capacities of 600 mAh g(-1), 50% higher than those achieved for bulk Ga under identical testing conditions.

No MeSH data available.


Related in: MedlinePlus