利用硝酸钴和铁氰化钾在水溶液中沉淀反应以及ZIF-8在水溶液中的部分分解,分别制备了2种组成相近但结构不同的双金属有机框架前驱体Co-Fe precursor和ZCF precursor。经过多巴胺包覆,对2种产品在氩气气氛下退火获得碳化产物。将碳化产物与纳米硫粉混合得到的碳/硫复合材料(E-CoFeCN@C/S、E-ZCF@C/S)分别作为正极,组装扣式锂硫电池并测试电化学性能。利用X射线衍射仪、扫描电子显微镜、透射电子显微镜、热重分析仪进行形貌和结构分析。在组成相似的情况下,核壳结构碳载体(E-CoFeCN@C)与发散式结构碳载体(E-ZCF@C)对锂硫电池性能的影响呈现出“此消彼长”的特点:E-ZCF@C/S在循环伏安测试中表现出更小的极化以及更强的电流响应,在电化学阻抗测试中表现出更低的电荷转移阻抗,表明该材料有利于促进正极电荷传递过程,即加快电极反应动力学。E-ZCF@C/S在0.2C倍率下放电初始比容量为1211.3mAh/g,在2C倍率下放电初始比容量为794mAh/g,均优于E-CoFeCN@C/S。而核壳结构的优势主要体现在容量衰减方面,E-CoFeCN@C/S在0.2C倍率下经过100次循环后平均衰减率为0.074%(E-ZCF@C/S为0.26%),在2C倍率下循环300次后平均衰减率为0.047%(E-ZCF@C/S为0.13%),说明核壳结构对活性物质的锚固作用明显而对电荷转移不利。
Two bimetallic organic framework precursors,Co-Fe precursor and ZCF precursor,with similar compositions but different structures,were obtained by partial decomposition of ZIF-8 in an aqueous solution and the precipitation reaction of Co(NO3)2 and K3Fe(CN)6 in an aqueous solution.After dopamine coating,the carbonized products were obtained by annealing of the two products in argon atmosphere.The carbon/sulfur composites (E-CoFeCN@C/S,E-ZCF@C/S) prepared by mixing the carbonized products with sulfur nanopowder were used as cathodes,respectively,for assembling button lithium-sulfur batteries and testing the electrochemical performance.The morphology and structure of the samples were characterized and analyzed by X-ray diffractometer (XRD),scanning electron microscope (SEM),transmission electron microscope (TEM) and thermal gravimetric analyzer (TG).With similar composition,the influence of the core-shell structure (E-CoFeCN@C) and the divergent structure of carbon carriers (E-ZCF@C) on the performance of the lithium-sulfur battery was opposite;when one was rising,the other was falling.E-ZCF@C/S showed smaller polarization and stronger current response in cyclic voltammetry test,and lower charge transfer impedance in electrochemical impedance test,indicating that this material was beneficial to promote the positive charge transfer process,i.e.,to accelerate the electrode reaction kinetics.E-ZCF@C/S exhibited an initial discharge specific capacity of 1211.3 mAh/g at 0.2C rate and 794 mAh/g at 2C rate,both of which were significantly better than E-CoFeCN@C/S.The advantage of the core-shell structure was mainly reflected in the capacity attenuation.The average decay rate of E-CoFeCN@C/S after 100 cycles at 0.2C was 0.074% (E-ZCF@C/S was 0.26%),and after 300 cycles at 2C was 0.047% (E-ZCF @ C/S was 0.13%),indicating that the core-shell structure could anchor the active material significantly but was unfavorable for charge transfer.
[1] Tollefson J.Can the world kick its fossil-fuel addiction fast enough[J].Nature,2018,556(7702):422-425.
[2] Albina Jetybayeva,Arman Umirzakov,Berik Uzakbaiuly,et al.Towards Li-S microbatteries:a perspective review[J].Journal of Power Sources,2023,573(7):233158.
[3] Wu F,Maier J,Yu Y.Guidelines and trends for next-generation rechargeable lithium and lithium-ion batteries[J].Chem Soc Rev,2020,49:1569-1614.
[4] Liu B,Fang R,Xie D,et al.Revisiting scientific issues for industrial applications of lithium-sulfur batteries[J].Energy & Environmental Materials,2018,1:196-208.
[5] Lei J,Liu T,Chen J J,et al.Exploring and understanding the roles of Li2Sn and the strategies to beyond present Li-S batteries[J].Chem,2020,6(10):2533-2557.
[6] Wang Weiyu,Hou Mingxiu,Han Fangqian,et al.Three-in-one LaNiO3 functionalized separator boosting electrochemical stability and redox kinetics for high-performance Li-S battery[J].Journal of Energy Chemistry,2023,82(7):581-591.
[7] Barchasz C,Leprêtre J C,Alloin F,et al.New insights into the limiting parameters of the Li/S rechargeable cell[J].Journal of Power Sources,2012,199:322-330.
[8] Ma Chao,Geng Hui,Liu Xizheng,et al.Low concentration salt triggered in-situ asymmetric gel electrolyte for Li-S battery[J].Electrochimica Acta,2023,439(1):141640.
[9] Zhang X J,Chen L L,Yang Z,et al.Investigation of the structural effect of the carbon coated separator towards to the properties of Li-S batteries[J].Mater Lett,2021,290:129512.
[10] Chen X,Hou T,Persson K A,et al.Combining theory and experiment in lithium-sulfur batteries:current progress and future perspectives[J].Materials Today,2019,22:142-158.
[11] Gu Shenghan,Jiang Helong,Li Xiangcun,et al.Dispersing single-layered Ti3C2TX nanosheets in hierarchically-porous membrane for high-efficiency Li+ transporting and polysulfide anchoring in Li-S batteries[J].Energy Storage Materials,2022,53(12):32-41.
[12] Taner Zerrin,Shang Ruoxu,Dong Bo,et al.An overlooked parameter in Li-S batteries:the impact of electrolyte-to-sulfur ratio on capacity fading[J].Advanced Energy Materials,2022,104(12):107913.
[13] Zhao M,Li B Q,Peng H J,et al.Lithium-sulfur batteries under lean electrolyte conditions:challenges and opportunities[J].Angewandte Chemie International Edition,2020,59:12636-12652.
[14] Deng N,Liu Y,Li Q,et al.Functional double-layer membrane as separator for lithium-sulfur battery with strong catalytic conversion and excellent polysulfide-blocking[J].Chemical Engineering Journal,2020,382:122918.
[15] Li P Y,Deng J N,Li J,et al.Bifunctional interlayer for capturing polysulfide in Li-S battery[J].Journal Mater Sci,2019,54(18):11983-11990.
[16] Zhang C Y,Sun G W,Shi Z D,et al.Deciphering the catalysis essense of vanadium self-intercalated two-dimensional vanadium sulfides (V5S8) on lithium polysulfide towards high-rate and ultra-stable Li-S batteries[J].Energy Storage Materials,2021,43:471-481.
[17] Zhao C,Xu G L,Zhao T,et al.Beyond the polysulfide shuttle and lithium dendrite formation:addressing the sluggish sulfur redox kinetics for practical high-energy Li-S batteries[J].Angewandte Chemie International Edition,2020,59:17634-17640.
[18] Ku H Y,Pai J Y,Lu Y T,et al.Design of polyimide-based separators for effective suppression of self-discharge in non-aqueous electrical double layer capacitors[J].Journal of Power Sources,2021,514:230594.
[19] Deng C,Wang Z,Feng L,et al.Electrocatalysis of sulfur and polysulfides in Li-S batteries[J].Journal of Materials Chemistry A,2020,8(38):19704-19728.
[20] Du Z,Chen X,Hu W,et al.Cobalt in nitrogen-doped graphene as single-atom catalyst for high-sulfur content lithium-sulfur batteries[J].Journal of Colloid and Interface Science,2023,633(3):1042-1053.
[21] Ku H Y,Pai J Y,Lu Y T,et al.Design of polyimide-based separators for effective suppression of self-discharge in non-aqueous electrical double layer capacitors[J].Journal of Power Sources,2021,514:230594.
[22] Lin Jiaju,Zhou Yuan,Wen Jingbo,et al.Pyrrole derivatives as interlayer modifier of Li-S batteries:modulation of electrochemical performance by molecular perturbation[J].Journal of Energy Chemistry,2022,75(11):164-172.
[23] Niu H,Liu Y,Mao B,et al.In-situ embedding MOFs-derived copper sulfide polyhedrons in carbon nanotube networks for hybrid supercapacitor with superior energy density[J].Electrochim Acta,2020,329:135130.
[24] Ren J,Song Z,Zhou X,et al.A porous carbon polyhedron/carbon nanotube based hybrid material as multifunctional sulfur host for high-performance lithium-sulfur batteries[J].ChemElectroChem,2019,6:3410-3419.
[25] Meng J,Niu C,Xu L,et al.General oriented formation of carbon nanotubes from metalorganic frameworks[J].J Am Chem Soc,2017,139:8212-8221.
[26] Li Y J,Fan J M,Zheng M S,et al.A novel synergistic compo-site with multi-functional effects for high-performance Li-S batteries[J].Energy Environ Sci,2016,9:1998-2004.
[27] Tang J,Salunkhe R R,Liu J,et al.Thermal conversion of core-shell metal-organic frameworks:a new method for selectively functionalized nanoporous hybrid carbon[J].J Am Chem Soc,2015,137:1572-1580.
[28] Cheng Z,Xiao Z,Pan H,et al.Elastic sandwich-type rGO-VS2/S composites with high tap density:structural and che-mical cooperativity enabling lithium-sulfur batteries with high energy density[J].Adv Energy Mater,2018,8:1702337.
[29] Luo S,Sun W,Ke J,et al.A 3D conductive network of porous carbon nanoparticles interconnected with carbon nanotubes as the sulfur host for long cycle life lithium-sulfur batteries[J].Nanoscale,2018,10:22601-22611.
[30] Tian Y,Zhang X,Zhang Y G,et al.Cobalt-doped oxygen-deficient titanium dioxide coated by carbon layer as high-perfor-mance sulfur host for Li/S batteries[J].Journal of Alloy and Compounds,2021,861:157969.
[31] Pu J,Shen Z H,Zheng J X,et al.Multifunctional Co3S4@sulfur nanotubes for enhanced lithium-sulfur battery perfor-mance[J].Nano Energy,2017,37:7-14.
基金资助
山西省高等学校科技创新项目(2022L576);山西省基础研究计划自由探索类项目(202103021223003);大学生创新创业训练项目(20231457)
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