Charge-driven self-assembly synthesis of straw-sheaf-like Co3O4 with superior cyclability and rate capability for lithium-ion batteries

Abstract

Rational structure design of anode materials plays crucial roles in the continuous improvement of electrochemical lithium storage performance for high performance lithium-ion batteries (LIBs). In this study, a novel hierarchical straw-sheaf-like Co3O4 (Co3O4-SSL) composed of numerous strongly tied nanoneedles was successfully synthesized with hydrothermal route by a charge-driven self-assembly strategy. Material characterizations indicated that typical length of nanoneedles was about 10 µm and the average diameter was about 80 nm. Mechanism studies implied that positively charged diallyldimethylammonium chloride (DDA) molecules played a key role in the formation of straw-sheaf-like structures. Impressively, when Co3O4-SSL was investigated as anode materials for electrochemical lithium storage, high specific capacity (e.g. 842.9 mAh g−1 after 300 cycles tested at 500 mA g−1), superior cycling stability (e.g. capacity retention of about 100% over 300 cycles) and excellent rate capability (e.g. 707 mAh g−1 tested at 3000 mA g−1) were achieved in the repeated charging-discharging cycles, demonstrating great potentials in energy storage materials. The proposed synthetic strategy is appealing in electrode structure design for next generation LIBs.