xxii
List of Figures
Fig. 2.9
X-ray absorption near-edge structure (XANES) spectra
reproduced from Ref. [64] with permission from the American
Chemical Society. The red arrows mark the rough positions of
the main absorption edges .............................................
32
Fig. 2.10 An array of atoms illustrating the interactions used in the Monte
Carlo simulations (red lines) when calculating the probability of
accepting a move wherein atoms A and B are interchanged .......
33
Fig. 3.1
The Li–Mn–Ni oxide pseudo-ternary system where the corners
refer to the metals used during sample preparation and oxygen
content varies throughout the triangle. The bold lines represent
lithium containing single-phase regions known prior to the
current project. The open data points represent combinatorial
samples prepared at 800
◦ C in oxygen. The compositions were
determined by atomic absorption, and the lines leading to each
point begin at the as-dispensed compositions; if no line is present
the point lies directly above its dispensed composition.............
36
Fig. 3.2
a X-Ray diffraction (XRD) scan of a Li x Ni 2−x O 2 sample with
x = 1 as-dispensed with ammonium bicarbonate precipitator,
after heating to 400
◦ C in oxygen. The data are shown with the fit
and the difference plot immediately below. The position of the
sharp MgO peaks are indicated by
∗ . b Sample with x = 1 as
dispensed with hydroxide precipitator after heating to 400
◦ C in
air; with fit and difference plot. c The bulk sample (x = 0.965)
after heating in the thermo-gravimetric analyzer (TGA) in a flow
of argon. d Al 2 O 3 substrate after three treatments with LiOH.
Vertical lines indicate peaks from the JCPDS database.............
36
Fig. 3.3
Thermo-Gravimetric analyzer (TGA) data for samples of
Li 0.965 Ni 1.035 O 2 heated in oxygen (solid line), air (dashed line)
and argon (short dashed line). A gas flow of 50 mL/min was used
in each case. The vertical dashed lines mark the start and end of
the temperature holds...................................................
37
Fig. 3.4
TGA results for holds at 600, 700 and 800
◦ C in either oxygen
(solid lines) or air (dashed lines). The samples were heated at
20
◦ C/min and t = 0 min represents the moment when the
temperature first reached its intended value. The lithium content
was calculated from the mass loss using Eq. 3.1 assuming that
both lithium oxide and oxygen are lost...............................
39
Fig. 3.5
Unit cell volume versus x in Li x Ni 2−x O 2 obtained by
Goodenough et al. [71] (closed circles), Li et al. [36] (crosses),
and from the present work scanned on the JD-2000 and analyzed
with Rietveld refinement (open circles). The unit cell volume is
per Li x Ni 2−x O 2 formula unit ..........................................
40
Fig. 3.6
X-Ray diffraction (XRD) scans of nickel nitrate samples obtained
after co-precipitation, drying and heating to various temperatures.
List of Figures
Fig. 2.9
X-ray absorption near-edge structure (XANES) spectra
reproduced from Ref. [64] with permission from the American
Chemical Society. The red arrows mark the rough positions of
the main absorption edges .............................................
32
Fig. 2.10 An array of atoms illustrating the interactions used in the Monte
Carlo simulations (red lines) when calculating the probability of
accepting a move wherein atoms A and B are interchanged .......
33
Fig. 3.1
The Li–Mn–Ni oxide pseudo-ternary system where the corners
refer to the metals used during sample preparation and oxygen
content varies throughout the triangle. The bold lines represent
lithium containing single-phase regions known prior to the
current project. The open data points represent combinatorial
samples prepared at 800
◦ C in oxygen. The compositions were
determined by atomic absorption, and the lines leading to each
point begin at the as-dispensed compositions; if no line is present
the point lies directly above its dispensed composition.............
36
Fig. 3.2
a X-Ray diffraction (XRD) scan of a Li x Ni 2−x O 2 sample with
x = 1 as-dispensed with ammonium bicarbonate precipitator,
after heating to 400
◦ C in oxygen. The data are shown with the fit
and the difference plot immediately below. The position of the
sharp MgO peaks are indicated by
∗ . b Sample with x = 1 as
dispensed with hydroxide precipitator after heating to 400
◦ C in
air; with fit and difference plot. c The bulk sample (x = 0.965)
after heating in the thermo-gravimetric analyzer (TGA) in a flow
of argon. d Al 2 O 3 substrate after three treatments with LiOH.
Vertical lines indicate peaks from the JCPDS database.............
36
Fig. 3.3
Thermo-Gravimetric analyzer (TGA) data for samples of
Li 0.965 Ni 1.035 O 2 heated in oxygen (solid line), air (dashed line)
and argon (short dashed line). A gas flow of 50 mL/min was used
in each case. The vertical dashed lines mark the start and end of
the temperature holds...................................................
37
Fig. 3.4
TGA results for holds at 600, 700 and 800
◦ C in either oxygen
(solid lines) or air (dashed lines). The samples were heated at
20
◦ C/min and t = 0 min represents the moment when the
temperature first reached its intended value. The lithium content
was calculated from the mass loss using Eq. 3.1 assuming that
both lithium oxide and oxygen are lost...............................
39
Fig. 3.5
Unit cell volume versus x in Li x Ni 2−x O 2 obtained by
Goodenough et al. [71] (closed circles), Li et al. [36] (crosses),
and from the present work scanned on the JD-2000 and analyzed
with Rietveld refinement (open circles). The unit cell volume is
per Li x Ni 2−x O 2 formula unit ..........................................
40
Fig. 3.6
X-Ray diffraction (XRD) scans of nickel nitrate samples obtained
after co-precipitation, drying and heating to various temperatures.