# Graphene-Based Materials for the Separator Functionalization of Lithium-Ion/Metal/Sulfur Batteries
## 4 Conclusions and Perspective
While micromechanical cleavage can produce graphene sheets of just a few atomic layers with high accuracy, its low production efficiency restricts its application to laboratory settings. CVD is a commonly employed method to produce high-quality single-layer graphene material, but issues, such as the service life of templates and pollution from the etching process, need to be considered for large-scale industrial production. Pyrolysis with SFA encounters difficulties in completely removing the residual SFA, while SFA-free pyrolysis requires even more stringent production conditions. Liquid-phase exfoliation \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Separator** & **Rate Performance** & **Cycle Performance** & **Main Functions** & **Ref.** \\ \hline  & & Lithium-sulfur batteries & \\ \hline PP & 564, 533, 490, 141 mAh g\({}^{-1}\) at 0.2, 0.5, & 540 mAh g\({}^{-1}\) (0.5 C, after 150 cycles) & [142] \\  & 1, 2 C & & \\ \hline PG & 1038, 975, 903, 440 mAh g\({}^{-1}\) at 0.2, & 877 mAh g\({}^{-1}\) (0.5 C, after 150 cycles) & [142] \\  & 0.5, 1, 2 C & & \\ \hline PPy nanotube & 195, 187, & & \\ \hline  & 178, 162 mAh g\({}^{-1}\) at 0.5, 1, 2, 5 C & 801.6 mAh g\({}^{-1}\) (0.5 C, after 300 cycles) & [143] \\  & 1096, 1029, & & \\ \hline  & 966 mAh g\({}^{-1}\) at 0.5, 1, 2 C & 779 mAh g\({}^{-1}\) (0.5 C, after 300 cycles) & [144] \\ \hline  & 1128, 980, 833, 670, 586 mAh g\({}^{-1}\) at & & \\  & 0.75, 1, 5, 3, 6, 9 A g\({}^{-1}\) & & \\ \hline N-FOO & 1060, 927, & 758.3 mAh g\({}^{-1}\) (1 C, after 400 cycles) & [148] \\  & 779 mAh g\({}^{-1}\) at 0.5, 1, 2 C & & \\ \hline Ni\({}_{5}\)Sn\({}_{2}\)/NG & 1280, 5160, 1029, 927, 758, 788 mAh g\({}^{-1}\) & 758.3 mAh g\({}^{-1}\) (1 C, after 400 cycles) & [149] \\  & at 0.2, 0.5, 1, 2 C & & \\ \hline EUV/graphene & 824.4, 643, 518, 456.3 mAh g\({}^{-1}\) at 0.5, 1, & 640.5 mAh g\({}^{-1}\) (0.2 C, after 300 cycles) & [150] \\  & 1285, 1256, 870 mAh g\({}^{-1}\) at 0.2, 0.5, & 835 mAh g\({}^{-1}\) (0.5 C, after 100 cycles) & [3] Provide abundant active sites; (4) Ensure excellent thermal/mechanical stability. \\ \hline PAN/GO & 591, 448, 337 mAh g\({}^{-1}\) at 0.5 C, 1 C, & 597 mAh g\({}^{-1}\) (0.2 C, after 100 cycles) & [151] \\  & 2 C & & \\ \hline CoPc@GO-PP & - & 919 mAh g\({}^{-1}\) (0.5 C, after 250 cycles) & [153] \\ \hline SrF\({}_{2}\)-G/PP & 1131, 1083, 950, 878 mAh g\({}^{-1}\) at 0.5, & 811 mAh g\({}^{-1}\) (0.2 C, after 110 cycles) & [154] \\  & 1, 2, 5 C & & \\ \hline Ni@NG-CNTs-PP & 935, 822, 711, 545 mAh g\({}^{-1}\) at 0.5, 1, & 127 mAh g\({}^{-1}\) (2 C, after 900 cycles) & [155] \\  & 2, 5 C & & \\ \hline CuS/graphene-coated & 999, 864, 701, 523 mAh g\({}^{-1}\) at 0.5, 1, & 760 mAh g\({}^{-1}\) (0.2 C, after 100 cycles) & [156] \\ separator & 2, 5 C & & \\ \hline G@PP & 980, 833, 670, 586 mAh g\({}^{-1}\) at 15, & 663 mAh g\({}^{-1}\) (1.5 A g\({}^{-1}\), after 500 cycles) & [145] \\  & 6, 9 A g\({}^{-1}\) & & \\ \hline ODC/rGO-Coated Separator & 969, 844, 710, 465 mAh g\({}^{-1}\) at 0.5, 1, & 592 mAh g\({}^{-1}\) (1 C, after 600 cycles) & [157] \\  & 2, 5 C & & \\ \hline rGO@SL/PP & 701, 603, 490, 465 mAh g\({}^{-1}\) at 0.05, & 523 mAh g\({}^{-1}\) (2 C, after 1000 cycles) & [158] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._is a low-cost method for preparing large-scale few-layer graphene, but it is challenging to control the layer number and avoid restacking of the graphene layer during extended production times. In terms of application in separator modification, further research is needed to understand the mechanism of electron/Li\({}^{+}\) transfer kinetics and the interaction between the graphene-based interlayer and electrolytes/electrodes. Additionally, new composite strategies, rational structure design schemes, and improved film formation and coating methods need to be developed.