Carbon-coated Na2Li2Ti6O14 sub-micro-wires as high-rate and ultra-long cycling anode materials for lithium-ion batteries

Abstract In this paper, Na2Li2Ti6O14 sub-micro-wires (NLTO-MWs) and Na2Li2Ti6O14@C sub-micro-wires (NLTO@C-MWs) as anode materials are synthesized through electrospinning and subsequent calcination methods. All samples have shown the nanowire morphology with the diameter size distribution ranging from 300 to 400 nm. The diameters of NLTO@C-MWs are about 350 nm with the carbon layer approximately 4 nm thickness on its surface. The electrochemical tests have shown that NLTO@C-MWs delivers an initial charge capacity of 110.1 mAh g-1 at 100 mA g-1 and capacity retention of 98.73% upon 400 cycles. Specifically, NLTO@C-MWs can still maintain high reversible capacity of 86.89 mAh g−1 at 1000 mA g-1 after 3000 cycles. The excellent performance can be ascribed to the uniformly dispersed carbon layer and unique three-dimensional sub-micro networks of the NLTO-MWs, which can provide a good transport framework to greatly improve the transfer rates of electrons and lithium-ions and effectively alleviate the volume fluctuation effect during charge-discharge process. The superior electrochemical performance demonstrates that the NLTO@C-MWs is one of the promising candidate anode materials for lithium-ion batteries. Meanwhile, the carbon coating modification methodology may provide a novel strategy to promote the research of anode materials in lithium-ion batteries.