Complex permittivity‐dependent plasma confinement‐assisted growth of asymmetric vertical graphene nanofiber membrane for high‐performance Li‐S full cells. Issue 7 (17th February 2022) - Zhang, Yongshang
Abstract: Vertical graphene (VG), possessing superior chemical, physical, and structural peculiarities, holds great promise as a building block for constructing a high‐energy density lithium‐sulfur (Li‐S) battery. Therefore, it is desirable to develop a new VG growth technique with a novel structure to enable wide applications. Herein, we devise a novel complex permittivity‐dependent plasma confinement‐assisted VG growth technique, via asymmetric growing a VG layer on one side of N‐doped carbon nanofibers for the first time, using a unique lab‐built high flux plasma‐enhanced chemical vapor deposition system, as a bifunctional nanofiber membrane to construct Li‐S batteries with low negative/positive (N/P) and electrolyte/sulfur (E/S) ratios. The unique nanofiber membrane could simultaneously protect the cathode and anode, enabling an excellent electrochemical performance with low N/P and E/S ratios in Li‐S batteries. Such a full cell delivers high gravimetric energy density and volumetric energy density of 340 Wh kg −1 and 547 Wh L −1, respectively, at low N/P (2:1) and E/S (4:1) ratios. Furthermore, a pouch cell achieves a high areal capacity of 7.1 mAh cm −2 at a sulfur loading of 6 mg cm −2 . This work put forward a novel pathway for the design of high‐energy density Li‐S batteries. Abstract : A new technique of complex permittivity‐dependent plasma confinement‐assisted method for asymmetric vertical graphene growth is developed. This method enables a vertical graphene layer grown on one side of N‐doped carbon fibers, which could serve as an asymmetric membrane to protect sulfur cathode and lithium anode, enabling a stable cycle life and high‐energy density in lithium‐sulfur (Li‐S) batteries.