Copper sulfides nanocrystals encapsulated in polypyrrole nanotubes for stable lithium storage.

• CuS nanoparticles embedded in PPy nanotubes are fabricated. • The CuS/PPy promotes Li+ ion diffusion and inhibits the aggregation of the electrode. • CuS/PPy exhibit better electrochemical performance. Copper sulfides with high electrical conductivity and theoretical capacity can be potentially applied as anode for Lithium-ion batteries (LIBs). However, some disadvantages including large volume expansion and the formation of polysulfides still exist. Herein, CuS nanocrystals embedded in the polypyrrole nanotubes are synthesized using FeOOH as sacrificial template. The unique structure can offer elastic buffer effect and restrict agglomeration and pulverization, resulting in the better electrochemical performance as anodes for LIBs. [ABSTRACT FROM AUTHOR]