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

Abstract

Abstractα-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 α-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 α-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 α-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.

Mechanochemical synthesis of Li-rich (Li2Fe)SO cathode for Li-ion batteries

“…However, the other probability of minor existence of FeS and LiFeO 2 in the ball-milled (Li 2 Fe)SO and their appearance upon improvement of the crystallinity by heat treatment cannot be excluded. Although the electrochemical activity of LiFeO 2 27 and FeS, 28 their observed amounts in the heat-treated (at 500 °C) ball-milled (Li 2 Fe)SO (0.15 vol%, and 0.2 vol%, respectively) suggest negligible contribution to the delivered capacity and the overall electrochemical performance. The decrease of XRD intensity of peak p3 at 500 °C suggests unstable thermal behaviour for its corresponding phases (FeS and LiFeO 2 based on Rietveld analysis).…”