Carbon shell coated hollow NiCoSe_(x)composite as high-performance anode for lithium storage

摘要

Hollow NiCoSe_(x)(H-NiCoSe_(x)) nanospheres encapsulated with carbon shell were prepared via one-step easy solvothermal method followed by the carbon coating process.H-NiCoSe_(x)@C has large interior void with the uniform dimension around 350 nm and the thickness of carbon shell around 20-30 nm.Coupling with the large interior void as well as robust protective carbon shell,H-NiCoSe_(x)@C can retain the reversible capacity of 805.6 mAh·g^(-1) after 100 cycles at 200 mA·g^(-1).In particular,H-NiCoSe_(x)@C delivers large reversible capacity of 1532.2 mAh·g^(-1) upon cycling for 1000 loops at 1000 mA·g^(-1)with the capacity retention as high as 128.2% upon long period of activation.Even at the high rate of 3000 mA·g^(-1),its specific capacity still retains up to 659.3 mAh·g^(-1).The superior lithium storage performances for H-NiCoSe_(x)@C profit from its robust hollow core-shell structure as well as enhanced electrical conductivity and ion transport.