Electrocatalytic and stoichiometric reactivity of 2D layered siloxene for high-energy-dense lithium-sulfur batteries  

作　　者：Hui-Ju Kang Jae-Woo Park Hyun Jin Hwang Heejin Kim Kwang-Suk Jang Xiulei Ji Hae Jin Kim Won Bin Im Young-Si Jun 

机构地区：[1]Department of Advanced Chemicals&Engineering,Chonnam National University,Gwangju,Republic of Korea [2]Division of Analytical Science,Korea Basic Science Institute(KBSI),Daejeon,Republic of Korea [3]Department of Applied Chemistry,Hanyang University,Ansan,Gyeonggi-do,Republic of Korea [4]Department of Chemistry,Oregon State University,Corvallis,Oregon,USA [5]Division of Materials Science and Engineering,Hanyang University,Seoul,Republic of Korea

出　　处：《Carbon Energy》2021年第6期976-990,共15页碳能源（英文）

基　　金：supported by the R&D Convergence Program of NST(National Research Council of Science&Technology)of the Republic of Korea(CAP-15-02-KBSI);a National Research Foundation of Korea(NRF)grant funded by the Korean Government(MSIT)(no.2019R1C1C1007745);a National Research Foundation of Korea(NRF)grant funded by the Korean Government(Ministry of Science,ICT&Future Planning)(no.2019R1A4A2001527).

摘　　要：Lithium-sulfur batteries(LSBs)have emerged as promising power sources for high-performance devices such as electric vehicles.However,the poor energy density of LSBs owing to polysulfide shuttling and passivation has limited their further market penetration.To mitigate this challenge,two-dimensional(2D)siloxene(2DSi),a Si-based analog of graphene,is utilized as an additive for sulfur cathodes.The 2DSi is fabricated on a large scale by simple solvent extraction of calcium disilicide to form a thin-layered structure of Si planes functionalized with vertically aligned hydroxyl groups in the 2DSi.The stoichiometric reaction of 2DSi with polysulfides generates a thiosulfate redox mediator,secures the intercalation pathway,and reveals Lewis acidic sites within the siloxene galleries.The 2DSi utilizes the corresponding in-situ-formed electrocatalyst,the 2D confinement effect of the layered structure,and the surface affinity based on Lewis acid-base interaction to improve the energy density of 2DSi-based LSB cells.Combined with the commercial carbon-based current collector,2DSi-based LSB cells achieve a volumetric energy density of 612 Wh Lcell^(−1) at 1 mA cm^(−2) with minor degradation of 0.17%per cycle,which rivals those of state-of-the-art LSBs.This study presents a method for the industrial production of high-energy-dense LSBs.

关 键 词：2D confinement effects Lewis acid-base interactions lithium-sulfur batteries siloxenes thiosulfate-polythionate redox couple 

分 类 号：TM912[电气工程—电力电子与电力传动]