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1

Electrochemical and Corrosion Behavior of Nanocrystalline TiNi-Based Alloys and Composite

100%

Balcerzak M., Jurczyk M.

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vol. 126

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issue 4

888-891

EN

In this work TiNi-based nanocrystalline alloys and composite were produced by mechanical alloying process with subsequent annealing at 750°C for 0.5 h. Mechanical alloying was performed in a SPEX 8000 Mixer Mill. TiNi alloy was chemically modified by Ag elemental powder. Silver content equaled 5 wt%. X-ray diffraction analyses revealed formation of TiNi main phase after annealing. Additionally, two minor phases Ti_2Ni and TiNi_3 were detected for unmodified alloy. Crystallites of obtained powders were nanosized. Corrosion and electrochemical measurements were performed in 6 M KOH solution. All synthesized materials were used as negative electrode for Ni-MH_x batteries. Ag addition positively affects on stability of discharge capacity of TiNi alloy during of charge/discharge tests.

2

The Influence of Chemical Modification by Silver on Hydrogen Storage Properties of Nanocrystalline Ti_2Ni Alloy

100%

Balcerzak M., Jurczyk M.

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vol. 126

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issue 4

892-894

EN

In this study mechanical alloying process with subsequent annealing at 750°C for 0.5 h were used to produce Ti_2Ni-based nanocrystalline alloys and composite. To improve electrochemical properties, Ti-Ni-based alloy was chemically modified by 5 wt% of silver powder. X-ray diffraction analyses showed formation of nanocrystalline Ti_2Ni main phase. Electrochemical studies revealed a positive effect of chemical modification by silver on Ti_2Ni alloy. All synthesized materials were used as negative electrodes for Ni-MH_x batteries. The highest discharge capacity equaled 303 mAh/g, at 40 mA/g discharge current. All electrochemical measurements were done in 6 M KOH solution.

3

Calculations of Molecular Structures and Processes Important for Hydrogen Behaviour in the Li-Amide/Imide System

70%

Ivanović N., Radisavljević I., Novaković N., Manasijević M., Colognesi D.

Acta Physica Polonica A

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2011

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vol. 120

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issue 2

242-245

EN

Lithium amide (LiNH_{2}) and imide (Li_{2}NH) have recently attracted much attention as part of the Li-H-N system suitable for hydrogen (H) storage applications. However, the ground-state imide structure is still unknown with at least six candidate structures, with ground state energies all very close to one another. In order to discover possible pathways for the imide-amide-imide transformations during the hydrogen absorption/desorption cycles, we have examined the molecular structures involved (along with their changes during these processes) using ab-initio calculations based on the linear combination of atomic orbitals (LCAO). In addition, the influence of Li substitution by some other elements of interest on the system behaviour was investigated. These analyses were complemented by density functional theory (DFT) calculations of several crystal structures appearing in the processes. In this way a thorough insight into the structures and the processes taking place at atomic level is attained, providing a starting point for understanding these complicated systems, and the mechanisms governing their transformations.

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3 Acta Physica Polonica A

2 2014

1 2011

2 Balcerzak M.

2 Jurczyk M.

1 Colognesi D.

1 Ivanović N.

1 Manasijević M.

1 Novaković N.

1 Radisavljević I.

Electrochemical and Corrosion Behavior of Nanocrystalline TiNi-Based Alloys and Composite

The Influence of Chemical Modification by Silver on Hydrogen Storage Properties of Nanocrystalline Ti_2Ni Alloy

Calculations of Molecular Structures and Processes Important for Hydrogen Behaviour in the Li-Amide/Imide System