Electrostatic layer-by-layer self-assembly of 1D alpha-LiFeO2 with enhanced rate capability and cycling performance

摘要

alpha-LiFeO2 is a promising cathode material for lithium-ion batteries due to its theoretically high specific capacity (282 mAh g(-1)), abundant nature, low cost of raw materials and environmental friendliness. However, the intrinsic sluggish kinetics and poor electronic conductivity of alpha-LiFeO2 prevent its practical use. In this work, we introduce a novel electrostatic layer-by-layer self-assembly method using PAH and PSS charged polyelectrolytes to grow in situ Ag nanoparticles on the surface of alpha-LiFeO2 nanorods to improve the electronic and ionic conductivity in this material. The experimental results show that such tailored design effectively improves the cycling stability and provides the material with a superior rate capability. The Ag-1D alpha-LiFeO2 material delivers a high discharge capacity of 162.6 mAh g(-1) at 0.5 C and a capacity retention of 89.6% after 50 cycles. The excellent electrochemical behavior may be ascribed to synergistic effects which combine the use of Ag NPs, which provide with improved electronic conductivities, and the large specific surface areas given by the 1D morphology of the nanorods, providing increased lithium and electron conduction pathways.