Electrochemical activation of novel Fe-based Li-rich cathode material for lithium-ion batteries

Abstract

Li-rich layered oxide has been consistently studied especially due to its high lithium storage capability. Here, Fe-based Li-rich cathode material (Li[Li0.1Fe0.18Ni0.27Mn0.45]O2) with a novel proportion has been successfully synthesized by a simple basic molten salt method using an eutectic mixture of LiNO3-LiOH·H2O. Compared to solution chemistry (co-precipitation method), the molten salt environment leads to fine particles with a well-defined layered structure. The prepared material delivers a reversible specific capacity of 220.1 mA h g−1 after 43 cycles in the voltage range of 2–4.8 V at 20 mA g−1, which is much higher than that of the other reported Fe-containing Li-rich cathode materials. Such superior charge-discharge capacity can be mainly attributed to the gradually activation of electrochemical reactions below 3.5 V and over 4.2 V during cycling. These Li-rich materials prepared by molten salt method are considered promising cathode materials for high-capacity lithium-ion batteries.