KOH selective etching synthesis and electrochemical performance of nano porous Li2FeSiO4/C composite

Nano porous Li 2 FeSiO 4 /C composite (LFS-10S) was prepared by KOH selective etching Li 2 FeSiO 4 -(SiO 2 ) 0.1 /C composites. This method allows directly pore-creating on Li 2 FeSiO 4 crystal. Common porous Li 2 FeSiO 4 /C (LFS) were also prepared as a control. LFS-10S and LFS were characterized by XRD, SEM, TEM and nitrogen adsorption/desorption test. XRD analysis shows that the LFS-10S material was composed of crystalline particles with a monoclinic crystal system in the P 2 1 space group. SEM and TEM tests indicate that the particle size of LFS-10S is 20 ∼ 30 nm. The nitrogen adsorption/desorption test shows that the specific surface area of LFS-10S is 123.23 m 2 /g, larger than that of LFS (71.56 m 2 /g). These features make LFS-10S exhibit better electrochemical performance over LFS. The specific discharge capacity of LFS-10S at 0.1 C is as high as 235.2 mA h g −1 , higher than that of LFS (158.4 mA h g −1 ). Moreover, the rate performance, cycling performance and lithium ion diffusion coefficient of LFS-10S are all better than those of LFS.