Effect of non-stoichiometry on the charge storage capacity of NiO conversion anodes in Li-ion batteries

Towards Control of the Size, Composition and Surface Area of NiO Nanostructures by Sn Doping

“…LO mode is commonly attributed to Ni 2+ -O stretching mode [ 27 ], which is expected to be weak or not observed in the Raman signal from stoichiometric NiO. The presence of this LO mode in the Raman spectra from the analyzed nanoparticles could be related to the presence of defects in NiO, such as Ni vacancies [ 28 , 29 ] or the presence of Ni 3+ [ 30 ]. The Raman spectra from Sn doped NiO nanostructures show additional weak modes centered on 702 and 875 cm −1 corresponding to 2TO and TO+LO optical modes in NiO [ 25 , 26 ], respectively, not showing Raman peaks corresponding to SnO 2 or other Sn-based compounds.…”

Stoichiometry–grain size-specific capacitance interrelationships in nickel oxide

“…Thus, the various mole fractions of nickel species estimated from XPS corroborate with the color variations in samples, and is consistent with the reported literature using ferrometric titration. 18 The CVs from all the samples at a representative scan rate of 35 mV s À1 are shown in Fig. 4a.…”

“…Chemical features include mainly the relative fractions of Ni 2+ and Ni 3+ . 18 For example, an Ni x O with a higher fraction of Ni 3+ was demonstrated to be more facile as anode for Li-ion batteries. 18 The charge storage capacity of Li-ion batteries containing only Ni 2+ (40 mA h g −1 ) is about seven times less than that of the Ni 3+ containing counterparts (280 mA h g −1 ).…”

“… 18 For example, an Ni x O with a higher fraction of Ni 3+ was demonstrated to be more facile as anode for Li-ion batteries. 18 The charge storage capacity of Li-ion batteries containing only Ni 2+ (40 mA h g −1 ) is about seven times less than that of the Ni 3+ containing counterparts (280 mA h g −1 ). 18 In another study, Kim et al observed that the concentration of Ni 3+ decreased with annealing temperature.…”

Thermal conductivity of intercalation, conversion, and alloying lithium-ion battery electrode materials as function of their state of charge

“…We choose Fe2O3 and NiO as model conversion systems. Due to slow diffusion kinetics for alloying electrode materials, diffusion coefficients of lithium in Fe2O3 (DLi ~ 10 -141 cm 2 s -1 ) [33] and NiO (DLi ~ 10 -131 cm 2 s -1 ) [34] are orders of magnitude lower than intercalation electrode materials. Both Fe2O3 and NiO are poor electrical conductors, in both lithiated and delithiated forms.…”