Complex permittivity‐dependent plasma confinement‐assisted growth of asymmetric vertical graphene nanofiber membrane for high‐performance Li‐S full cells

Abstract

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.

Keywords

• asymmetric
• complex permittivity
• electrospinning
• Li‐S batteries
• vertical graphene