Electrochimica Acta, Vol.219, 163-169, 2016
Tuning the carbon content on TiO2 nanosheets for optimized sodium storage
Titanium dioxide (TiO2) has been considered as a promising anode candidate for sodium ion batteries (NIBs). In this work, we report the synthesis of anatase TiO2 nanosheets coated by nitrogen doped carbon derived from dopamine precursor (TiO2@C) as high performance anode materials for NIBs applications. The carbon contents can be controlled from 2.6 wt% to 10.4 wt% by varying the polymerization time of dopamine. X-ray diffraction patterns confirm there is no phase change after carbon coating. When employed as an anode for NIBs, the TiO2@C composites exhibit improved electrochemical performances in terms of higher specific capacity and better cycling stability compared to pure TiO2 nanosheets. Notably, with a carbon content of 4.8 wt%, the TiO2@C nanosheets delivers a reversible capacity of 180 mA h g(-1) and shows stable cycling performance with no discharge capacity decay from 2nd cycle onward over 50 cycles. Even at high current density of 10C, the capacity still remains 82 mA h g(-1). The excellent cycling stability and rate performances can be ascribed to the protective effects of carbon coating layer which reserves the structure stability and enhances electrical conductivity during cycling. (C) 2016 Elsevier Ltd. All rights reserved.