Suppressing the Voltage Decay and Enhancing the Electrochemical Performance of Li1.2Mn0.54Co0.13Ni0.13O2 by Multifunctional Nb2O5 Coating

This study focuses on suppressing the voltage decay and improving the electrochemical performance of Li-rich and manganese-based (LRM) material by Nb 2 O 5 coating, which is realized by an effective soft-chemical route using a mixture of ethanol and water as co-solvent. After Nb 2 O 5 coating, the resulted material demonstrates superior electrochemical performance as cathode material for LIBs. Particularly, it shows an excellent capacity retention of 98 % after 200 cycles at 1 C (1 C=250 mA g −1 ). Voltage decay within cycling is also obviously suppressed by Nb 2 O 5 coating. Moreover, it exhibits superior rate capacities, delivering 189 and 152 mAh g −1 at high current densities of 2 and 5 C, respectively. The improved electrochemical performance of Nb 2 O 5 coated sample can be attributed to that Nb 2 O 5 can suppress the phase transformation and voltage decay by acting as not only a fast ion conductor to accelerate the lithium ion diffusion at the cathode/electrolyte interface, but also an inert protective layer to reduce the direct contact between the cathode and electrolyte.