Synthesis of Si nanosheets by using Sodium Chloride as template for high-performance lithium-ion battery anode material

摘要

Due to the shorter path length and more channels for lithium ion diffusion and insertion, the two-dimensional (2D) Si nanosheets exhibit superior electrochemical performances in the field of electrochemical energy storage and conversion. Recently, various efforts have been focused on how to synthesize 2D Si nanosheets. However, there are many difficulties to achieve the larger area, high purity of 2D Si nanosheets. Herein, we developed a facile and scalable synthesis strategy to fabricate 2D Si nanosheets, utilizing the unique combination of the water-soluble NaCl particles as the sacrificial template and the hydrolyzed tetraethyl orthosilicate as the silica source, and assisting with the magnesium reduction method. Importantly, the obtained Si nanosheets have a larger area up to 10 mu m(2). Through combining with reduced graphene oxides (rGO), the Si nanosheets@rGO composite electrode exhibits excellent electrochemical performances. It delivers high reversible capacity about 2500 mAh g(-1) at the current density of 0.2 A g(-1), as well as an excellent rate capability over 900 mAh g(-1) at 2 A g(-1) even after 200 cycles.