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, SnO2/Si@graphite hybrid anodes, with nano-SnO2 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 SnO2 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, SnO2/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.