LiMn1.5Ni0.5O4 materials modified by AlPO4 are prepared by a sol-gel method with citric acid to improve their electrochemical performance. The physical and electrochemical properties of the samples are characterized by various analytical techniques. The coated AlPO4 layer completely covers the surfaces of the LiMn1.5Ni0.5O4 particles and the thickness of the coated layer is ∼15 nm. Moreover, the surface and charge-transfer resistances of the modified electrode are much lower than those of the pristine sample, and the lithium diffusion rate of the modified electrode was also significantly enhanced. As a result, the modified materials demonstrate improved electrochemical properties, even under elevated temperature conditions. This improvement is attributed to minimization of the side-reactions between the cathode and electrolyte by the AlPO4 protecting layer, the suppression of the formation of an undesirable SEI layer, and the partial absorption of the stress caused by the volume change during cycling. Therefore, surface modification by AlPO4 is an effective way to improve the performance of LiMn1.5Ni0.5O4 cathode materials for lithium-ion batteries.
ASJC Scopus subject areas
- Chemical Engineering(all)