P2-type Na0.67Co0.35Ti0.20Mn0.44La0.01O2 cathode material with high-rate capability for sodium-ion batteries

The substitution of elements has attracted great interest to enhance the electrochemical properties of sodium-ion batteries (SIBs). Herein, the P2-Na0.67Co0.35Ti0.20Mn0.45-xLaxO2 electrode samples were prepared via a solid-state route. The effect of La3+ substitution was researched as high-rate SIBs cathode. The Na0.67Co0.35Ti0.20Mn0.44La0.01O2 exhibits a superior initial specific capacity of 162.7 and 125.9 mA$h/g after 50 cycles at 0.1C rate, and the initial specific discharge capacity of 115.2 mA$h/g with 60.6% capacity retention after 100 cycles at 1C. In addition, the Na0.67Co0.35Ti0.20Mn0.44La0.01O2 sample shows an excellent rate capacity of 91.9 and 60.4mA$h/g with 46.9% and 50.9% capacity retentions even at 8C and 10C rate after 100 cycles, respectively. The promising La-substituted P2-type Na0.67Co0.35Ti0.20Mn0.45-xLaxO2 material provides a new strategy for designing high-rate performance of SIBs. (C) 2019 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.