화학공학소재연구정보센터
Applied Surface Science, Vol.425, 614-621, 2017
Two-dimensional sandwich-like Ag coated silicon-graphene-silicon nanostructures for superior lithium storage
Two-dimensional (2D) sandwich-like Ag coated silicon-graphene-silicon (Ag@Si-rGO-Si) nanosheets are designed and synthesized as a novel anode material for superior lithium storage. The mesoporous Si nanofilm grows tightly on the two sides of reduced graphene oxide (rGO), and Ag nanoparticles with a size of 10-50 nm are further coated on the surface of porous Si nanofilm. Such unique features not only provide a short pathway for rapid Li+ diffusion and electron transportation, but also can act as a buffering effect to effectively inhibit the huge volume expansion of pure Si during the repeated lithiation/delithiation process. Meanwhile, a conductive network is constructed by the embedded graphene coupled with Ag nanoparticles to overcome the shortage of pure Si with low electrical conductivity. The resultant 2D sandwich-like Ag@Si-rGO-Si electrode exhibits a high reversible capability (1382 mAh g(-1) at 0.1 A g(-1) after 100 cycles), long cycle stability (952 mAh g(-1) at 1 A g(-1) after 500 cycles) and excellent high-rate performance (863 mAh g(-1) at 2 A g(-1), 565 mAh g(-1) at 5 A g(-1)). (C) 2017 Elsevier B.V. All rights reserved.