Chapter 5
Combinatorial Studies of the Spinel and
Rocksalt Regions in the Li–Mn–Ni–O System
5.1 Experimental Design
In order to map out the entire Li–Mn–Ni–O system, combinatorial samples were
made at over 300 different compositions using the method described in Sect. 2.1.1.
Figure 5.1 shows these compositions. Due to the large amount of data used in producing the phase diagrams, the supporting evidence is split between two chapters.
Figure 5.2 shows the phase diagrams obtained in oxygen. In this chapter, evidence
for the spinel and rocksalt phases will be presented. The two-phase regions between
Mn 2 O 3 and the spinel structures as well as between the spinel and rocksalt materials
will also be examined here.
In the lithium loss study described in Chap. 3, two different precipitators were used
to cause coprecipitation of the Li, Mn, and Ni mixed nitrate solutions: ammonium
bicarbonate and ammonium hydroxide. Although ammonium bicarbonate precipitates all three metals and the hydroxide only precipitates the Mn and Ni atoms, no
significant differences were obtained by using either precipitator in the lithium loss
study, or in this study. As such, no distinctions will be made in this chapter between
the two precipitators, as in all cases, the phases obtained were identical suggesting
that ionic transport at high temperature overcomes any lithium inhomogeneity in the
starting material.
5.2 Spinel Single-Phase Region
Figure 5.2a shows the phase diagram obtained in this study when samples were heated
to 800
◦ C in an oxygen flow and then quenched to room temperature. Figure 5.2 b
shows the phase diagram obtained under the same conditions with the regular cooling
rate. Figure 5.3 shows the partial phase diagram obtained by heating to 800
◦ C in air
with regular cooling.
Data in this chapter are reprinted from Ref. [80] with permission from Elsevier.
61
E. McCalla, Consequences of Combinatorial Studies of Positive Electrodes
for Li-ion Batteries, Springer Theses, DOI 10.1007/978-3-319-05849-8_5,
© Springer International Publishing Switzerland 2014
Combinatorial Studies of the Spinel and
Rocksalt Regions in the Li–Mn–Ni–O System
5.1 Experimental Design
In order to map out the entire Li–Mn–Ni–O system, combinatorial samples were
made at over 300 different compositions using the method described in Sect. 2.1.1.
Figure 5.1 shows these compositions. Due to the large amount of data used in producing the phase diagrams, the supporting evidence is split between two chapters.
Figure 5.2 shows the phase diagrams obtained in oxygen. In this chapter, evidence
for the spinel and rocksalt phases will be presented. The two-phase regions between
Mn 2 O 3 and the spinel structures as well as between the spinel and rocksalt materials
will also be examined here.
In the lithium loss study described in Chap. 3, two different precipitators were used
to cause coprecipitation of the Li, Mn, and Ni mixed nitrate solutions: ammonium
bicarbonate and ammonium hydroxide. Although ammonium bicarbonate precipitates all three metals and the hydroxide only precipitates the Mn and Ni atoms, no
significant differences were obtained by using either precipitator in the lithium loss
study, or in this study. As such, no distinctions will be made in this chapter between
the two precipitators, as in all cases, the phases obtained were identical suggesting
that ionic transport at high temperature overcomes any lithium inhomogeneity in the
starting material.
5.2 Spinel Single-Phase Region
Figure 5.2a shows the phase diagram obtained in this study when samples were heated
to 800
◦ C in an oxygen flow and then quenched to room temperature. Figure 5.2 b
shows the phase diagram obtained under the same conditions with the regular cooling
rate. Figure 5.3 shows the partial phase diagram obtained by heating to 800
◦ C in air
with regular cooling.
Data in this chapter are reprinted from Ref. [80] with permission from Elsevier.
61
E. McCalla, Consequences of Combinatorial Studies of Positive Electrodes
for Li-ion Batteries, Springer Theses, DOI 10.1007/978-3-319-05849-8_5,
© Springer International Publishing Switzerland 2014