SnSe nanocrystals decorated on carbon nanotubes for high-performance lithium-ion battery anodes

•SnSe nanocrystals integrated with carbon nanotube were successfully obtained a facile colloidal synthetic method.•Downsized SnSe nanocomposites exhibit excellent electrochemical property in lithium ion battery.•The reaction mechanism of SnSe NC/CNT is elucidated by operando XRD and ex-situ XAS.