Optimization of Ni2+/Ni3+ ratio in layered Li(Ni,Mn,Co)O2 cathodes for better electrochemistry

Effect of ZnO modification on the performance of LiNi0.5Co0.25Mn0.25O2 cathode material

“…It can be seen that the XPS spectra of O1s are composed of two peaks at 531.7 and 529.6 eV, respectively. The peak around 531.7 eV is related to the oxygen in carbonate impurities on the surface such as Li 2 CO 3 or LiOH [22][23][24]. The peak around 529.6 eV is associated with lattice oxygen in LiNi 0.5 Co 0.25 Mn 0.25 O 2 [22][23][24] and Zn-O bond in ZnO [25].…”

“…However, the O1s spectra of both electrodes after cycles are quite different and can be used to analyze the SEI layer on the cathode particles. In general, the O1s spectra include a broad major peak around 531-534 eV which can be mainly attributable to the component of SEI layer, such as Li 2 CO 3 and LiOH (centered at ∼531.6 eV, containing some surface impurities on the LiNi 0.5 Co 0.25 Mn 0.25 O 2 particles), polyether and ROCO 2 Li (centered at ∼533 eV), ROCO 2 Li (centered at ∼534 eV) [24,30], and another shoulder peak around 529-530 eV which is mainly attributable to the lattice oxygen [22][23][24] or the oxygen in ZnO [25]. Compared with the O1s spectra of the materials without contacting the electrolyte in Fig.…”

Synthesis and characterization of carbon-coated LiNi1/3Co1/3Mn1/3O2 cathode material prepared by polyvinyl alcohol pyrolysis route

“…These results suggest that the structure of LiNi 1/3 Co 1/3 Mn 1/3 O 2 is not affected by the carbon coating. [2,[17][18][19], and indicate that the valence states of Ni, Co an Mn in the sample PVA0 are mainly +2, +3 and +4. For the sample PVA20 with the largest carbon content, the binding energies of Ni, Co and Mn are 854.2, 799.7 and 642.1 eV, respectively, which are almost same as the ones of PVA0.…”

Influence of sintering temperature on the structure and high-temperature discharge performance of LiNi1/3Mn1/3Co1/3O2 cathode materials

“…When the sintering temperature increases to 800 and 900 ℃, well-defined peak splits are both observed, indicating the formation of better layered structure. Besides, only the ratio of I (003) / I (104) at 800 ℃ shown in Table 1 is larger than 1.2, indicating the higher degree of cation order and better electrochemical properties [23,[35][36] .…”