Abstract
The pristine NaTi2(PO4)3 negative electrode material has a poor electrical conductivity, which significantly inhibits its application in sodium-ion batteries. Herein, carbon coating and Gd3+ doping are simultaneously applied to promote the electrical conductivity of NaTi2(PO4)3 through a simple sol-gel approach. The conductive carbon coating promotes apparent conductivity, while Gd3+-doping effectively improves intrinsic conductivity. Therefore, the resulting Gd3+-doped NaTi2?xGdx(PO4)3@C (x=1%, 3%, 5%, 7%) composites display superior high-rate capabilities for sodium energy storage. A typical obtained NaTi1.95Gd0.05(PO4)3@C anode presents high capacities of 105.9 and 93.1 mAh g?1 at 5 and 10 C, respectively. Furthermore, this anode shows a high capacity retention ratio of 95.2% at 20 C over 500 cycles. These results suggest that this carbon coating and doping strategy is highly effective and can be adopted to enhance the battery properties of other electrode materials.
NSTL
Elsevier