Improving the lithium storage performance of SnO2 nanoparticles by in-situ embedding into a porous carbon framework

Abstract

Wide attention has been recently paid to the potential application of nanosized SnO2 material in lithium-ion batteries as a new high performance anode owe to its high theoretical specific capacity and moderate working potential. However, the intrinsic problems, such as pronounced volume change and low conductivity, make the capacity decay quickly and rate capability behave badly, therefore severely hindering the practical application of nanosized SnO2 in lithium-ion batteries. Herein, to improve the electrochemical performances, SnO2 nanoparticles have been in-situ embedded into a characteristic porous carbon framework via a facile strategy to form SnO2 nanoparticles/porous carbon framework composite (SnO2 NPs@PC). The as-fabricated SnO2 NPs@PC has three main advantages in lithium storage: Firstly, the good conductive porous carbon framework provides SnO2 with adequate free space (pores) for accommodation of volume change, as well as enhance the conductivity of whole composite; Secondly, the SnO2 NPs@PC with a individual porous architecture has more surface active sites for electrochemical reaction and accessorial contact interfaces between electrode and electrolyte; Finally, the ultrafine SnO2 nanoparticles would have shortened electrons/lithium-ions diffusion distances compared to their bulk counterparts. As a result, the SnO2 NPs@PC gets robust structural stability and improved electrochemical kinetics, therefore exhibits outstanding performances, revealing capacities of 730 and 564 mAh g−1 at 200 and 1000 mA g−1 after 400 and even 1000 cycles, respectively. By comparison with the control samples of pure SnO2 NPs and SnO2 NPs@C, it is demonstrated that the electrochemical performances of SnO2 nanoparticles embedded in a well-designedly peculiar porous carbon framework (SnO2 NPs@PC) have been improved significantly.