Improvement of electrochemical propertis of Li(1.1)Al(0.05)Mn(1.85)O(4) achieved by an AlF(3) coating

Abstract

The electrochemical performance of AlF(3)-coated Li(1.1)Al(0.05)Mn(1.85)O(4) spinel was investigated. The morphology of the AlF3-coated Li(1.1)Al(0.05)Mn(1.85)O(4) was observed by SEM and TEM, and the thickness of the coating layer was approximately 10 nm. Capacity retention and rate capability were substantially improved by the AlF(3)-coating, as compared to pristine Li(1.1)Al(0.05)Mn(1.85)O(4). Manganese dissoulution was also dramatically reduced for the AlF(3)-coated Li(1.1)Al(0.05)Mn(1.85)O(4), which may reflect lower impedance for the coated spinel. The thermal stability of the AlF(3)-coated Li(1.1)Al(0.05)Mn(1.85)O(4) was improved, exhibiting an exothermic reaction at higher temperature with reduced heat generation, compared to the pristine Li(1.1)Al(0.05)Mn(1.85)O(4).