Free-standing integrated cathode derived from 3D graphene/carbon nanotube aerogels serving as binder-free sulfur host and interlayer for ultrahigh volumetric-energy-density lithium sulfur batteries

By Haodong Shi, Xuejun Zhao, Zhong‐Shuai Wu, Yanfeng Dong, P. Lu, Jian Chen, W. Ren, Hui‐Ming Cheng, X. Bao. Nano Energy, 2019

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Abstract The actual applications of lithium sulfur (Li S) batteries are significantly obstructed by limited cyclability and low volumetric-energy-density due to the shuttling effect of polysulfides and low mass density of sulfur cathode. Herein, we report a free-standing, compact, conductive and integrated cathode (G/CNT-S//G/CNT), constructed by compressing graphene/carbon nanotubes (G/CNT) aerogels, simultaneously serving as bi-functionalities of binder- and metal-current-collector-free sulfur host (G/CNT-S) and interlayer (G/CNT), for high volumetric-energy-density Li S batteries. The G/CNT aerogels display three-dimensional interconnected porous network, large surface area (363 m2 g−1) and high electrical conductivity (67 S m−1), which can endow the cathode with ultrahigh volumetric mass density (1.64 g cm−3) and superior electron-ion transport network. Meanwhile, the compressed ultralight G/CNT film can act as flexible interlayer for synergistically suppressing the polysulfide shuttling via both chemical interaction and physical restriction. Consequently, the compact cathodes, achieve high capacity of 1286 mAh g−1 at 0.2 C and long-term cyclability with an extremely low decay rate of 0.06% over 500 cycles at 2 C. Most importantly, our compact cathodes represent unprecedented volumetric capacity of 1841 Ah L−1 and volumetric-energy-density of 2482 Wh L−1, both of which are the highest values of Li S batteries reported to date. Therefore, this proposed strategy will open a new avenue for developing high volumetric-energy-density Li S batteries.

Subfields: Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/31eb064da1fae856a36263ad1dced761d067017a