Layered Li0.45(Ni0.8Co0.15Al0.05)O2 and Li0.55(Ni1/3Co1/3Mn1/3)O2 materials have been, respectively, prepared by a chemical delithiation of layered Li(Ni0.8Co0.15Al0.05)O2 and Li(Ni1/3Co1/3Mn1/3)O2 compounds using NO2BF4 oxidizer in an acetonitrile medium. The thermal gravimetric results show that both Li0.45(Ni0.8Co0.15Al0.05)O2 and Li0.55(Ni1/3Co1/3Mn1/3)O2 powders release oxygen starting from 190 and 250 °C with an overall oxygen loss of 11 and 9 wt% at 900 °C, respectively. The results show that the oxygen release from these delithiated powders was associated with the occurrence of several structural transformations, ranging from a R3¯m→Fd3m (layered → spinel) transition to a Fd3m → Fm3m (spinel → NiO-type) transition. The 3 wt% weight gain, solely observed for Li0.55(Ni1/3Co1/3Mn1/3)O2 between 800 °C and room temperature, involved a reversible Fd3m⇆Fm3m(spinel⇆NiO-type) structural transition. The reactivity of these delithiated powders with electrolytes was investigated by a differential scanning calorimetry (DSC) between room temperature and 375 °C. In the case of Li0.55(Ni1/3Co1/3Mn1/3)O2 powder, the DSC result shows that the oxidation of the electrolyte was delayed by 50 °C toward high temperatures with the generation of lower heat when compared to Li0.45(Ni0.8Co0.15Al0.05)O2 powder. The relationship between the safety characteristics of Li0.45(Ni0.8Co0.15Al0.05)O2 and Li0.55(Ni1/3Co1/3Mn1/3)O2 powders and their thermal stability was discussed in the light of their structural rearrangement during the thermal heating processes.
[1]
Daniel P. Abraham,et al.
Surface changes on LiNi0.8Co0.2O2 particles during testing of high-power lithium-ion cells
,
2002
.
[2]
C. Delmas,et al.
Thermal Stability of Lithium Nickel Oxide Derivatives. Part II: LixNi0.70Co0.15Al0.15O2 and LixNi0.90Mn0.10O2 (x = 0.50 and 0.30). Comparison with LixNi1.02O2 and LixNi0.89Al0.16O2
,
2003
.
[3]
E. Roth,et al.
Thermal abuse performance of high-power 18650 Li-ion cells
,
2004
.
[4]
Herbert L Case,et al.
An accelerated calendar and cycle life study of Li-ion cells.
,
2001
.
[5]
G. L. Henriksen,et al.
Aluminum-doped lithium nickel cobalt oxide electrodes for high-power lithium-ion batteries
,
2004
.
[6]
Ilias Belharouak,et al.
Li(Ni1/3Co1/3Mn1/3)O2 as a suitable cathode for high power applications
,
2003
.
[7]
C. Delmas,et al.
Thermal stability of lithium nickel oxide derivatives. Part I: LixNi1.02O2 and LixNi0.89Al0.16O2 (x = 0.50 and 0.30)
,
2003
.
[8]
James McBreen,et al.
In situ X-ray diffraction and X-ray absorption studies of high-rate lithium-ion batteries
,
2001
.
[9]
A. Manthiram,et al.
Synthesis and characterization of P3-type CoO2-δ
,
2002
.