Effect of film stress on electrochemical properties of lithium manganese oxide thin films

Using radio frequency magnetron sputtering, we fabricated spinel-phase LiMn2O4 films with different thicknesses. The stress state of the 200 nm-thick films maintained the compressive stress and that of the 400 nm-thick films changed from compressive to tensile stress during annealing. During the cycle test, the amount of volume change in the 400 nm-thick films was larger than that in the 200 nm-thick films. In the case of the 400 nm-thick, micro-cracks on the surface were generated during the cycle test and this phenomenon caused the stress transition and also a harmful effect on the cycle retention of the cathode thin films. [Copyright &y& Elsevier]