Abstract
Na_(0.44)MnO_2 microrods with high crystallinity have been prepared by a simple solid-phase method and then coated with ln_2O_3 by precipitation method. 1 wt% ln_2O_3 coating could improve the sodium-storage capability of Na_(0.44)MnO_2 microrods significantly. The original Na_(0.44)MnO_2 microrods could provide the maximum discharge capacity of 100.3 mAh g~(-1) under a wide voltage of 2.0-4.5 V at 1 C, but the discharge capacity rapidly decreases to 70.4 mAh g~(-1) after 400 cycles, which was only 70.3% of the maximum capacity. However, the Na_(0.44)MnO_2 coated with 1 wt% In_2O_3 exhibited a high discharge capacity of 90.9 mAh g~(-1) after 400 cycles, with high-capacity retention of 86.7% in the same case. Moreover, compared with Na_(0.44)MnO_2, 1 wt% In_2O_3 coated Na_(0.44)MnO_2 shows better rate capability. Even at a high current density of 10 C, the discharge capacity is 63.6 mAh g~(-1), much larger than the 32.9 mAh g~(-1) of the pristine Na_(0.44)MnO_2. The mechanism of In_2O_3 coating improving the electrochemical performance of Na_(0.44)MnO_2 microrods was studied in detail.
NSTL
Elsevier