Integrated and Three-Dimensional Network Structure of a SiNWs/CNTs@MOFs Composite to Enhance the Silicon Anode’s Electrochemical Performance in Lithium-Ion Batteries

Abstract

Constructing the architectural stable silicon composite is significantly critical to enhance the Si electrode cycle life of lithium-ion batteries in which the inevitable volume expansion exerts huge mechanical stress within the Si anode, then bringing about the destruction of the silicon structure and unsatisfactory cyclic performance. In this work, we report an integrated and three-dimensional (3D) network structure of the SiNWs/CNTs@MOFs composite, prepared by a facile in situ growth method. The metal–organic framework (MOF)-derived porous coating and the 3D conducting network structure of the SiNWs/CNTs@C precursor, hand in hand, construct a structurally stable composite, with the SiNW cores fully covered by the MOF coating. Attributing to MOF-derived porous coating, high conductivity of CNTs, and the stable three-dimensional network structure, not only the transport of ions and electrons facilitates but also the stability of the structure during the electrochemical process maintains. The resulting integrated SiNWs/CNTs@MOFs composite enhances the electrode durability and presents a reversible capacity of 1223 mAh g–1 at a current density of 100 mA g–1 for 100 cycles and a rate capacity of 765 mAh g–1 at a high current density of 5 A g–1.