A Facile Strategy to Construct Silver-Modified, ZnO-Incorporated and Carbon-Coated Silicon/Porous-Carbon Nanofibers with Enhanced Lithium Storage.

For Si anode materials used for lithium ion batteries (LIBs), developing an effective solution to overcome their drawbacks of large volume change and poor electronic conductivity is highly desirable. Here, the composites of ZnO-incorporated and carbon-coated silicon/porous-carbon nanofibers (ZnO-Si@C-PCNFs) are designed and synthesized via a traditional electrospinning method. The prepared ZnO-Si@C-PCNFs can obviously overcome these two drawbacks and provide excellent LIB performance with excellent rate capability and stable long cycling life of 1000 cycles with reversible capacity of 1050 mA h g-1 at 800 mA g-1 . Meanwhile, anodes of ZnO-Si@C-PCNFs attached with Ag particles display enhanced LIB performance, maintaining an average capacity of 920 mA h g-1 at a large current of 1800 mA g-1 even for 1000 cycles with negligible capacity loss and excellent reversibility. In addition, the assembling method with important practical significance for a simple pouch full cell is designed and used to evaluate the active materials. The Ag/ZnO-Si@C-PCNFs are prelithiated and assembled in full cells using LiNi0.5 Co0.2 Mn0.3 O2 (NCM523) as cathodes, exhibiting higher energy density (230 W h kg-1 ) of 18% than that of 195 W h kg-1 for commercial graphite//NCM523 full pouch cells. Importantly, the comprehensive mechanisms of enhanced electrochemical kinetics originating from ZnO-incorporation and Ag-attachment are revealed in detail.