Experimental Section

Synthesis of multilayer-graphene nanowalls anchored on carbon paper：The carbon paper used

was commercialized Toray carbon paper (CP). Every CP was tailored to be a wafer of 16mm in

diameter. Subsequently, the mutilayer-graphene nanowalls would be grown on this CP substrate using RF-PECVD. The parameters were 200W (power), 890℃ (temperature), 30min (time) and 1000Pa (pressure), and the gas employed was CH4:Ar =20sccm:80sccm. Each side of CPs was treated for 30min. Every cut CP was weighed using an electron balance (Sartorius BT125D), with the weight of the cut CP in the 15.5 - 15.8mg range and the weight of the CPVG approximately 0.02 - 0.04 mg more after coating.

Synthesis of Li2S@CPVG cathode：CPVG was firstly prepared as host and current collector of Li2S

by PECVD. Then 0.5M lithium sulfide ethanol solution was prepared in vacuum glove box (Xiamen Tmaxcn Inc.), and 30µL configured solution was taken and dropped onto the CPVG, and then Li2S@CPVG cathode was  harvested after dry at 80℃. The weight difference of Li2S@CPVG cathode after dry was measured by electronic balance, which reflects the weight of Li2S.

Electrochemical Measurements: Electrochemical experiments were performed on CR2032 coin cells assembled, using a coin cell crimper (Xiamen Tmaxcn Inc.), in an argon-filled glove box with lithium foil(14mm) as the counter and reference electrodes. The prepared multilayer-graphene nanowalls anchored on CP(CPVG) were used as the cathode (working) electrodes. The membrane selected was Celgard 2325, and two electrolytes was used, 1MLiPF6 in EC/ DMC/DEC =1:1:1 (simply named ECe in this paper) and 1M LiTFSI and 3% LiNO3 in DOL/DME=1:1(simply named DOLe in this work). Electrochemical characterization was carried out on a battery tester (Xiamen Tmaxcn Inc.). The electrochemical impedance spectroscopic (EIS) data of the cells was characterized by PARSTAT 2273, and the parameters for EIS at the high frequency was1 MHz and at the low frequency 1 mHz. The applied voltage was the open circuit voltage of battery. Every EIS was tested after wetting for more than 30min. Cyclic Voltammetry (CV) was performed using a CHI660e electrochemical analyzer. The experiments were carried out on 2032 coin cells consisting of CP and CPVG working electrodes, Li foil reference/counter electrodes and the DOLe electrolyte. The ECe and DOLe electrolytes were commercial electrolytes purchased from DoDoChem.

Materials Characterization: A Raman spectrometer equipped with a 514.5nm laser (JY T64000,

Horiba Jobin Yvon Corp.) was used to characterize the surface carbon bonding in CP and CPVG. The surface structure and elemental mapping of CP and CPVG was performed by FESEM (Field emission scanning electron microscopy, HITACHI, SU-8010 & S-4800) equipped with EDS. To obtain the interfacial information in the fibers of CP and CPVG, the samples were randomly cracked. The surface chemical element and chemical bonding for SEI film characterization was taken by X-ray photoelectron spectroscopy (VG (R3) scienta R3000). For the microstructural characterization, HRTEM, STEM and EELS analyses were carried out using TEM (FEI, ThemisZ & Carl Zeiss, Libra 200 HT Mc Cs). The materials after cycling in battery testing were separated using the MSK-110D decrimper, and the samples cleaned using DME solution and ethanol solution in succession.