Simultaneous doping of magnesium (Mg) and gallium (Ga) at the Ni-site in Li
NiO2 has been tried to improve the cathode performance, in view of the rece
nt reports that Ga or Mg dopants can suppress the crystallographic phase tr
ansitions and decrease the irreversible capacity. The results show that co-
doping (2 atom% Ga and 3 atom% Mg) definitely has a large beneficial effect
in increasing the capacity (150 mAh/g) and cycling behavior. Comparison of
the differential capacity vs. voltage curves for pristine and co-doped LiN
iO2, show suppression of the phase transitions and stabilization of the hex
agonal (H1) phase. Differential scanning colorimetry (DSC) data indeed conf
irm the above by way of increased thermal stability of the charged cathode.
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