Nanostructure distortion improvement of Al doped spinel LiMn_2O_4 films deposited by RF magnetron sputtering for flexible high-voltage lithium ion batteries

摘要

This research set out to deposit spinel aluminum doped LiMn2O4, using radio frequency magnetron sputtering as a cathode material for flexible high-voltage lithium ion batteries. Magnetron sputtering has the high plasma needed to form the close-package of octahedral and tetrahedral sites, and so these effects of different deposition pressures (1, 5, and 10 mTorr) and annealing temperatures (550, 650 and 750 degrees C) were investigated. The results showed that these films became loose with the increasing of the deposition pressure, and the annealing temperature could improve nanostructures, especially for the z-axis distortion of Al doped spinel LiMn2O4. The x-ray diffraction peaks showed no defects in the heterogeneous Mn2O3 structures at the LiAl0.1Mn1.9O4 film. The charge-transfer impendent Rct of LiAl0.1Mn1.9O4 was 578 Omega low than 755 Omega obtained with LiMn2O4. Also, LiAl0.1Mn1.9O4 with 98 % of the 50-th battery charge-discharge retention was considered to be better than LiMn2O4 with 95 % of the charge-discharge retention.