Control of atomic ordering of LiNiO2 thin films on a sapphire substrate from rock-salt to layered structure using uniaxial compression

Insight into the Role of Co and Mn Elements in Ni-Rich LiNi0.9CoxMn0.08–xAl0.02O2 Cathode Materials

“…It can be found that the refined calculated curves for all samples mainly coincide with the actual test curves, and the values of R p and R wp in the refined results are less than 10%, indicating that the refined results are accurate and reliable. For layered cathode materials, the value of c / a is frequently used to indicate the ordering of hexagonal layered structures. − As shown in Table , the c / a values for the NCMA9352, NCMA9532, and NCMA9712 samples are 4.9381, 4.9419, and 4.9397, respectively, all of which are larger than 4.9, indicating that the hexagonal layered structure is ordered for all samples. In addition, the ratio of I (003) / I (104) is normally used to reflect the degree of Li + /Ni 2+ mixing of extreme nickel cathode materials, and severe Li + /Ni 2+ mixing is not conducive to Li + intercalation and deintercalation, thus damaging the capacity. , However, an appropriate mixture of lithium/nickel is beneficial to the stability of the layered structure due to the “column effect” of Ni 2+ . , It can be seen from Table that the I (003) / I (104) ratios of NCMA9352, NCMA9532, and NCMA9712 samples are 1.7734, 1.9100, and 1.7813, respectively, all of which are greater than 1.2, indicating that the Li + /Ni 2 mixing degree of all samples is not elevated. , It can also be seen from Table that the lattice parameter c increases gradually for the NCMA9352, NCMA9532, and NCMA9712 samples, which are 14.1715, 14.1730, and 14.1752 Å, respectively.…”