Flexible Electrocatalytic Nanofiber Membrane Reactor for Lithium/Sulfur Conversion Chemistry
作者: Ji, L (Ji, Lei); Wang, X (Wang, Xia); Jia, YF (Jia, Yongfeng); Hu, QL (Hu, Quanli); Duan, LM (Duan, Limei); Geng, ZB (Geng, Zhibin); Niu, ZQ (Niu, Zhiqiang); Li, WS (Li, Weishan); Liu, JH (Liu, Jinghai); Zhang, YG (Zhang, Yuegang); Feng, SH (Feng, Shouhua)
标题: Flexible Electrocatalytic Nanofiber Membrane Reactor for Lithium/Sulfur Conversion Chemistry
来源出版物: ADVANCED FUNCTIONAL MATERIALS
卷: 30
期: 28
文献号: 1910533
DOI: 10.1002/adfm.201910533
提前访问日期: MAY 2020
出版年: JUL 2020
摘要: Severe lithium polysulfide (LiPS) shuttle effects and sluggish electrochemical conversion kinetics constitute bottlenecks in developing fast-rechargeable, high-energy, and high-power Li/S batteries. Here, a flexible and conductive TiN-Ti4O7 core-shell nanofiber (TiNOC) membrane reactor is designed to electrocatalytically mediate Li/S conversion chemistry. The Ti, N, and O atoms in the nanofiber function as electrocatalysts and chemical confinement active sites to initiate long-chain LiPS conversion and phase change, as well as to suppress soluble LiPS shuttling. With a sulfur cathode-membrane reactor module configuration, Li/S cells possess a high sulfur utilization of 91.20%, good rate capability of 869.10 mA h g(-1), and high capacity retention of 92.49%, with a coulomb efficiency of 99.57% after 200 cycles at 5 C. Density functional theory (DFT) calculations revealed that the optimized chemisorption configurations facilitate the elongation of Li-S and S-S bonds, as well as charge transfer along Ti-S and Li-N bonds, which favors bond breakage, bond formation, and the activation of solid-state S-8, Li2S2, and Li2S. Layer-by-layer module stacking provides Li/S batteries with a high areal sulfur loading of 12.00 mg cm(-2) to deliver a high areal capacity of 14.40 mA h cm(-2) at 2.26 mA. Two batteries in series can power real-world applications such as light emitting diode (LED) bulbs with a high energy output of 69.00 mW h.
关键词
作者关键词: chemisorption and electrocatalysis; conversion chemistry; Li; S batteries; membrane reactors; TiN-Ti4O7 core-shell nanofibers
KeyWords Plus: TOTAL-ENERGY CALCULATIONS; LI-S; SULFUR BATTERIES; CARBON NITRIDE; POLYSULFIDE REDOX; LONG-LIFE; PERFORMANCE; CAPACITY; HOST; HETEROSTRUCTURES