PPy-Encapsulated Na2Li2Ti6O14 Composites as High-Performance Anodes for Li-Ion Battery

Na2Li2Ti6O14 as a reliable anode material is becoming a hopeful candidate for Li-ion battery. Nevertheless, the pristine Na2Li2Ti6O14 usually suffer from bad rate performance and poor cycling stability under high current due to limited diffusion kinetics and poor electrical conductivity. Here, the PPy-coated Na2Li2Ti6O14 composites are successfully obtained via the solid-state method and followed by chemical oxidation process in the first time. The results of tests prove that the Na2Li2Ti6O14@PPy composites have better electrochemical performance than the bare Na2Li2Ti6O14 because of the excellent electrical conductivity and the special macromolecular architecture of PPy. In particular, the Na2Li2Ti6O14@PPy (4 wt%) exhibits excellent charge capacities of about 223.2, 218.0, 200.8, 184.3 and 172.6 mAh g(-1) at 50, 100, 200, 300 and 500 mA g(-1), respectively, revealing the best rate capability of all electrode materials. The Na2Li2Ti6O14@PPy(4 wt%) not only has the highest charge capacity under 0.5 mA g(-1), but also has the highest capacity retention of 85.12% among all samples after 100 loops. Hence, the PPy coating is known as a promising way to improve the electrochemical property of Na2Li2Ti6O14. The PPy-coated Na2Li2Ti6O14 demonstrates the great prospect as promising negative materials for Li-ion batteries.