| Abstract: | Rational electrode structure design is of great significance for realizing superior Na+storage performance.Herein, a metal salt-induced polymer blowing-bubble approach followed by selenization procedure is developed to in-situ generate abundant sub-10 nm CoSe_2 nanocrystals on 3D Se/N co-doped carbon networks(CoSe_2@3DSNC). The phase transition from Co to CoSe_2 and the incorporation of Se into the carbon layer are realized simultaneously to establish above configuration, in which the CoSe_2 nanocrystals are anchored on interlayer expanded carbon networks. Such unique configuration endows electrode with lower Na+diffusion energy barrier, higher Na+storage capability and better structural durability. Reflected in SIBs,the optimized CoSe_2@3 DSNC delivers superior rate capability(310 m Ah g~(-1) at 10 A g~(-1)) and excellent longterm cycling stability(409 m Ah g~(-1) after 1200 cycles at 5 A g~(-1)). Moreover, this configuration can also be obtained in other metal selenides-carbon composite through a similar approach. |
