文献类型：期刊文献

英文题名：Kinetically elevated redox conversion of polysulfides of lithium-sulfur battery using a separator modified with transition metals coordinated g-C3N4 with carbon-conjugated

作者：Chen, Manfang[1];Zhao, Xiaomei[2];Li, Yongfang[1];Zeng, Peng[1];Liu, Hong[1];Yu, Hao[1];Wu, Ming[1];Li, Zhihao[1];Shao, Dingsheng[1];Miao, Changqin[3];Chen, Gairong[3];Shu, Hongbo[1];Pei, Yong[2];Wang, Xianyou[1]

第一作者：Chen, Manfang

通讯作者：Wang, XY[1];Pei, Y[2]

机构：[1]Xiangtan Univ, Natl Local Joint Engn Lab Key Mat New Energy Stor, Hunan Prov Key Lab Electrochem Energy Storage & C, Natl Base Int Sci & Technol Cooperat,Sch Chem, Xiangtan 411105, Peoples R China;[2]Xiangtan Univ, Key Lab Green Organ Synth & Applicat Hunan Prov, Key Lab Environmentally Friendly Chem & Applicat, Sch Chem,Minist Educ, Xiangtan 411105, Peoples R China;[3]Xinxiang Univ, Chem & Chem Engn Sch, Xinxiang 453003, Henan, Peoples R China

第一机构：Xiangtan Univ, Natl Local Joint Engn Lab Key Mat New Energy Stor, Hunan Prov Key Lab Electrochem Energy Storage & C, Natl Base Int Sci & Technol Cooperat,Sch Chem, Xiangtan 411105, Peoples R China

通讯机构：[1]corresponding author), Xiangtan Univ, Natl Local Joint Engn Lab Key Mat New Energy Stor, Hunan Prov Key Lab Electrochem Energy Storage & C, Natl Base Int Sci & Technol Cooperat,Sch Chem, Xiangtan 411105, Peoples R China;[2]corresponding author), Xiangtan Univ, Key Lab Green Organ Synth & Applicat Hunan Prov, Key Lab Environmentally Friendly Chem & Applicat, Sch Chem,Minist Educ, Xiangtan 411105, Peoples R China.

年份：2020

卷号：385

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000507465200083)】；

基金：M. F. Chen and X. M. Zhao contributed equally to this work. This work is financially supported by the National Key Research and Development Program of China (Grant No. 2018YFB0104200) and the key project of strategies New Industry of Hunan Province (No. 2019GK2032).

语种：英文

外文关键词：Separator modification; Transition metals coordinated g-C3N4; Density functional theory calculation; Catalytic polysulfide redox conversion; Lithium-sulfur battery

摘要：Lithium-sulfur batteries have been regarded as promising energy storage candidates because of their high energy density and low cost. However, the low electrical conductivity of sulfur, infamous polysulfides shuttle and slow redox kinetics result in fast capacity fade and poor rate capabilities. To solve these barriers, herein a modification strategy of functional separator is presented by coating transition metal coordinated graphitic carbon nitride (g-C3N4) with crystalline carbons (M-C3N4/C) on the surface of a commercial separator. The coating layer exhibits both satisfactory interception ability for polysulfides shuttle and fast polysulfides conversion ability. It has been found that the uniformly distributed transition metal on g-C3N4/C acts as an active center to regulate polysulfides behavior via strong chemisorption capability and high catalytic activity towards polysulfide conversion, while the transition metal-interface guarantees the rapid electron transfer, which can consequently facilitate the utilization of active sulfur species. Notably, after considerable assessments from density functional theory calculations, spectroscopy and electrochemical performances, it can be concluded that the Ni-C3N4/C can strongly bind polysulfides and expedite polysulfides conversion kinetics as well as promote electrons/ion transfer. As a result, the lithium-sulfur batteries with Ni-C3N4/C-modified separator can deliver 999 mAh g(-1) at 0.5 A g(-1) with high capacity retention of 89.4% after 300 cycles. Even at a great sulfur loading of 4.6 mg cm(-2) and a low electrolyte/sulfur ratio of 6 mu L mg(-1), a large initial capacity of 724.6 mAh g(-1) is still obtained at 1.0 A g(-1). The separator reported in this work initiates the exploration of transition metals coordination as dynamic regulators of high-performance lithium-sulfur batteries and also reveals an understanding of the catalytic reactions.