In-situ embedding silicon nanoparticles into three-dimensional ZnSe/CoSe composites with carbon shell enables high-performance lithium-ion battery anode

Large theoretical capacity silicon (Si) anode for lithium-ion (Li-ion) battery is hindered by its large volumetric change and structural collapse during cycling. Here, we report a strategy that in-situ embedding Si nanoparticles (Si NPs) into flower-like selenides, then coating with carbon layer, forming a Si@ZnSe/CoSe@C anode. Engineered frame structure provides an optimized condition for alleviating volumetric of Si, and thereby improving stability. Additionally, carbon layer not only immobilize Si NPs, but also improves the conductivity. The Si@ZnSe/CoSe@C anode shows a capacity of 563 mAh g −1 after 150 cycles at 0.1 A g −1 , and a Coulombic efficiency as high as 99.4 % after cycling 800 times at 0.2 A g −1 . A 50 °C-tolerable performance is also obtained, showing a potential for applications. We believe that the composite design presented here offers a general method for developing high-performance energy-storage materials even though they intrinsically have large-volumetric change and low conductivity.