context: In order to further study the chemisorption of LiPSs on the electrodes, we carried out the visual adsorption experiment of Li2S6 on the CNF@V2S3 cathodes. As shown in Fig. 3g, the dark-yellow colour of Li2S6 solution containing CNF@V2S3 fades in the visible region obviously after 24 h; while the solution containing CNFs, by contrast, almost shows no change in its colour, directly demonstrating that CNF@V2S3 cathodes can anchor LiPSs strongly. Moreover, we also compare the colour change of the polypropylene separators used in the assembled LSBs. As shown in Fig. S6,† after 100 cycles, the separator in the LSBs based on CNF@V2S3 composites almost retains its own white colour; while that based on CNF@V2S3 and CNFs cathodes show an apparent change in colour from white to light yellow, especially that based on CNFs. These visual comparisons of the change in colour again indicate that the CNF@V2S3 composites could greatly inhibit the shuttling of LiPSs between the electrodes. Furthermore, first-principles simulations based on density functional theory (DFT) have been applied to theoretically study the chemisorption behaviours of LiPSs. Fig. 2h shows the adsorption conformation of LiPSs (Li2Sn: n = 2, 4 and 6) on the (204) plane of V2S3. And the Eads between V2S3 and Li2S/Li2S4/Li2S6 were estimated to be 1.29, 0.81 and 1.02 eV, which are much higher than those values of the Eads between C and LiPSs.
answer: CNF@V2S3 