Scalable High-Areal-Capacity Li-S Batteries Enabled by Sandwich-Structured Hierarchically Porous Membranes with Intrinsic Polysulfide Adsorption.

Li, Xiangcun; Zhang, Yue; Wang, Shuting; Liu, Yang; Ding, Yu; He, Gaohong; Jiang, Xiaobin; Xiao, Wu et al. · Nano Lett · 2020

basic_science · Level V

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Abstract

The key to realizing practical applications of Li-S batteries lies in scalable fabrication of cathode materials with high sulfur-loading and strong binding of lithium polysulfides (LiPSs). We report a scalable CeO<sub>2</sub>-CNT@C porous membrane with a large porosity of 90%. Introducing CNTs is critical to increase the porosity and construct porous networks with CNTs as the skeleton and CeO<sub>2</sub>-doped carbon as the shell. The macropores can improve the transport of Li<sup>+</sup> and electrolyte, while the porous networks possess high polysulfide-adsorbing and electron-transferring ability. The CeO<sub>2</sub>-CNT@C membrane can serve as an Al foil-free cathode and an interlayer for Li-S batteries. Moreover, CeO<sub>2</sub> can immobilize LiPSs and can alleviate its shuttle effect. The Li-S batteries with a sulfur loading of 6.2 mg cm<sup>-2</sup> deliver a capacity of 847 mA h g<sup>-1</sup> after 100 cycles, showing a high areal capacity of 5.25 mA h cm<sup>-2</sup> at a low electrolyte/sulfur ratio of 5.2 μL mg<sup>-1</sup>.