Abstract
SnO2 has been considered a promising anode material for lithium-ion batteries (LIBs) based on its high theoretical capacity (1494 mA h g?1). Unfortunately, the electrochemical properties, including rate performance and stability for SnO2-based materials, are still restrained by huge volume expansion and weak electron dynamics. Hence, we developed a one-step strategy for the synthesis based on non-aqueous sol-gel polypyrrole (PPy)-encapsulated SnO2 nanoparticles to solve the above issues. The synthesized material exhibits excellent dispersibility, and the SnO2 nanoparticles are encapsulated by the conductive coating (SnO2 @PPy-2). As an anode, SnO2 @PPy-2 demonstrates excellent electrochemical capabilities compared to pure SnO2 and SnO2 @PPy-1(based on pure SnO2 encapsulated PPy). SnO2 @PPy-2 not only exhibits 783.8 mAh g?1 and 932.6 mAh g?1 capacities at 0.5 A g?1(200 cycles) and 0.2 A g?1(100 cycles) but also retains an excellent rate performance for 560.2 mA h g?1 at 2 A g?1. This superior Li-storage performance can be ascribed to the reduced nanosize for SnO2 and the conductive polymer coating, which significantly enhances mass transfer efficiency. The existence of PPy dramatically restricts volume expansion and the agglomeration of Sn intermediates during charge/discharge. This work has also provided novel ways for the preparation of other disperse metal oxide/conductive-polymer composites.
NSTL
Elsevier