Structural engineering of Fe_(2.8)Sn_(0.2)O_4@C microano composite as anode material for high-performance lithium ion batteries

摘要

The design and synthesis of high-performance anode materials using environmentally friendly routes are demanded to meet the high-energy and high-power density requirements of next-generation lithium-ion batteries (LIBs). Herein, a facile and green gallic acid-assisted in situ synthetic strategy is demonstrated to fabricate novel Fe2.8Sn0.2O4@C composites as the anode materials of high-performance LIBs. The Fe2.8Sn0.2O4@C composites reveal a sphere-like morphology (2-3 um in diameter), which is composed of highly dispersed nano iron-tin oxide particles (similar to 25 nm) embedded in an interconnected carbon skeleton. This unique structure and composition allow Fe2.8Sn0.2O4@C to inhibit electrolyte adverse reactions, improve electron conductivity, and buffer mechanical stress for the entire electrode, resulting in its outstanding electrochemical performances. A high specific capacity of 2047 mA h g(-1) at 0.2 A g(-1) after 250 cycles, long cycling stability of 1061 mAh g(-1) at 1 A g(-1) after 1000 cycle, and rate capability of 572 mAh g(-1) at 10 A g(-1) are obtained. It is also indicated that the lithium storage in the Fe2.8Sn0.2O4@C anode involves both diffusion and surface capacitance mechanisms. The strategy reports here may open up new prospects for the design and manufacture of high-performance transition metal-based anode materials.