Graphene-like N,S-codoped bio-carbon nanosheets(GNSCS) were prepared by a facile and environment-friendly NaCl non-aqueous ionic liquid route to house sulfur for lithium-sulfur battery. The natural nori powder was cal...Graphene-like N,S-codoped bio-carbon nanosheets(GNSCS) were prepared by a facile and environment-friendly NaCl non-aqueous ionic liquid route to house sulfur for lithium-sulfur battery. The natural nori powder was calcined at 900°C for 3 h under Ar, in which NaCl non-aqueous ionic liquid can exfoliate carbon aggregates into nanosheets. The structural characterization of GNSCS by a series of techniques demonstrates the graphene-like feature.When evaluated as the matrix for sulfur cathode, GNSCS/S exhibits more prominent cycling stability and rate capability.A discharge capacity of 548 mA h g-1 at a current density of 1.6 A g-1 after 400 cycles was delivered with a capacity fade rate of only 0.13% per cycle and an initial Coulombic efficiency(CE) as high as 99.7%. When increasing the areal sulfur loading up to 3 mg cm-2, the discharge capacity can still be retained at 647 mA h g-1 after more than 100 cycles with a low capacity degradation of only ~0.30% per cycle. The features of N/S dual-doping and the graphene-like structure are propitious to the electron transportation, lithium-ion diffusion and more active sites for chemically adsorbing polysulfides. It is anticipated that other functional biochar carbon can also be attained via the low-cost, sustainable and green method.展开更多
基金the financial support from 973 Project of China (Grant No. 2005CB623601)National Natural Science Foundation of China (No. 20901072)China Postdoctoral Science Foundation (20090460723)~~
基金the financial supports provided by the National Natural Science Foundation of China (21601108 and U1764258)Young Scholars Program of Shandong University (2017WLJH15)+1 种基金the Fundamental Research Funds of Shandong University (2016JC033 and 2016GN010)the Taishan Scholar Project of Shandong Province (ts201511004)
文摘Graphene-like N,S-codoped bio-carbon nanosheets(GNSCS) were prepared by a facile and environment-friendly NaCl non-aqueous ionic liquid route to house sulfur for lithium-sulfur battery. The natural nori powder was calcined at 900°C for 3 h under Ar, in which NaCl non-aqueous ionic liquid can exfoliate carbon aggregates into nanosheets. The structural characterization of GNSCS by a series of techniques demonstrates the graphene-like feature.When evaluated as the matrix for sulfur cathode, GNSCS/S exhibits more prominent cycling stability and rate capability.A discharge capacity of 548 mA h g-1 at a current density of 1.6 A g-1 after 400 cycles was delivered with a capacity fade rate of only 0.13% per cycle and an initial Coulombic efficiency(CE) as high as 99.7%. When increasing the areal sulfur loading up to 3 mg cm-2, the discharge capacity can still be retained at 647 mA h g-1 after more than 100 cycles with a low capacity degradation of only ~0.30% per cycle. The features of N/S dual-doping and the graphene-like structure are propitious to the electron transportation, lithium-ion diffusion and more active sites for chemically adsorbing polysulfides. It is anticipated that other functional biochar carbon can also be attained via the low-cost, sustainable and green method.
