Indexed on: 21 Feb '20Published on: 20 Feb '20Published in: Chemistry - A European Journal
Low cost Si-based anode materials with excellent electrochemical lithium storage present attractive prospects for lithium-ion batteries (LIBs). Herein, porous Si-Cu3Si-Cu microsphere@C composites are designed and prepared by means of an etching/electroless deposition and subsequent carbon coating. The composites show a core-shell structure, with porous Si/Cu microsphere core surrounded by the N-doped carbon shell. The Cu and Cu3Si nanoparticles embed inside porous silicon microspheres, forming porous Si/Cu microsphere core. The microstructure and lithium storage performance of porous Si-Cu3Si-Cu microsphere@C composites can be effectively tuned by changing electroless deposition time. The Si-Cu3Si-Cu microsphere@C composite prepared with 12 min electroless deposition delivers a reversible capacity of 627 mAh g-1 after 200 cycles at 2 A g-1, showing an enhanced lithium storage. The super lithium storage performance of the Si-Cu3Si-Cu microsphere@C composite can be ascribed to the improved electronic conductivity, enhanced mechanical stability and better buffering against huge volume change in the repeated lithiation/delithiation processes. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.