Boosting the lithium storage performance of Na2Li2Ti6O14 anodes by g-C3N4 modification

Abstract

Na₂Li₂Ti₆O₁₄ particles were prepared by a simple solid-state process, and then g-C₃N₄-coated Na₂Li₂Ti₆O₁₄ composites were constructed by a facile solution route for the first time. The g-C₃N₄-coated Na₂Li₂Ti₆O₁₄ multicomponent composites because of their unique architecture as negative materials for Li-ion batteries can be expected to exhibit a significantly improved cycling stability and reversible capacity even at high rates. g-C₃N₄ (5 wt%)-coated Na₂Li₂Ti₆O₁₄ shows a discharge (charge) capacity of 184.4 (184.3) mA h g⁻¹ at 500 mA g⁻¹ after 100 cycles, which is larger than that of pristine Na₂Li₂Ti₆O₁₄ with a discharge (charge) capacity of 122.8 (122.0) mA h g⁻¹. The use of g-C₃N₄ with a carbon framework containing abundant nitrogen provides more active sites and surface defects for redox reactions and Li-ion transport. The g-C₃N₄ coating decreases the impedance between the electrolyte and Na₂Li₂Ti₆O₁₄ and enhances the charge transfer, ionic conductivity and diffusion ability of Li ions of Na₂Li₂Ti₆O₁₄. This work offers an efficient way to design high-performance Na₂Li₂Ti₆O₁₄-based materials for advanced lithium ion battery, and g-C₃N₄ (5 wt%)-coated Na₂Li₂Ti₆O₁₄ shows an enormous potential as a negative material for next generation Li-ion batteries with excellent performance.