Facile Synthesis of Hybrid Anodes with Enhanced Lithium-Storage Performance Realized by a "Synergistic Effect".

Alloying-type anodes including Si- and Sn-based materials are considered the most exploitable anodes for high-performance lithium-ion batteries. However, problems of poor kinetics properties and structural failures such as grain pulverization and coarsening hinder their large-scale application. Herein, SnO 2 /Si@graphite hybrid anodes, with nano-SnO 2 and nano-Si thoroughly mixed with each other and loaded onto graphite flakes, have been prepared by a facile ball milling method. Attributed to the "synergistic effect" between SnO 2 and Si, the mechanical stability and kinetics properties can be remarkably enhanced. Furthermore, graphite substrate supplies a fast electrically conductive path and buffers the volume expansion of active particles. Accordingly, SnO 2 /Si@graphite delivers 798.9 mAh g -1 at 200 mA g -1 and maintains 550.8 mAh g -1 after 1000 cycles at 1 A g -1 in half cells. Impressively, a high energy density of 431.4 Wh kg -1 (based on the mass of anode and cathode) can be obtained in full cells when paired with the NCM622 cathode. This work presents an effective strategy to exploit high-performance alloying-type anodes for LIBs by designing hybrid materials with multiple active components.