The Facile and Controllable Synthesis of Ultrafine Sn Nanocrystals Loaded on Carbon Black for High‐Performance Lithium Storage.

Sn and C nanocomposites are ideal anode materials for high‐energy and high‐power density lithium ion batteries. However, their facile and controllable synthesis for practical applications is still a critical challenge. In this work, a facile one‐step method is developed to controllably synthesize ultrafine Sn nanocrystals (< 5 nm) loaded on carbon black (Sn@C) through Na reducing SnCl4 by mechanical milling. Different from traditional up‐down mechanical milling method, this method utilizes mechanical milling to trigger bottom‐up reduction reaction of SnCl4. The in‐situ formed Sn nanocrystals directly grow on carbon black, which results in the homogeneous composite and the size control of Sn nanocrystals. The obtained Sn@C electrode is revealed to possesses large lithium diffusion coefficient, low lithiation energy barrier and stable electrochemical property during cycle, thus showing excellent lithium storage performance with a high reversible capacity (942 mAh g−1 at a current density of 100 mA g−1), distinguished rate ability (480 mAh g−1 at 8000 mA g−1) and superb cycling performance (730 mAh g−1 at 1000 mA g−1 even after 1000 cycles). [ABSTRACT FROM AUTHOR]