Catalyzing polysulfide conversion by g-C3N4 in a graphene network for long-life lithium-sulfur batteries
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The practical application of lithium-sulfur batteries with a high energy density has been plagued by the poor cycling stability of the sulfur cathode, which is a result of the insulating nature of sulfur and the dissolution of polysulfides. Much work has been done to construct nanostructured or doped carbon as a porous or polar host for promising sulfur cathodes, although restricting the polysulfide shuttle effect by improving the redox reaction kinetics is more attractive. Herein, we present a well-designed strategy by introducing graphitic carbon nitride (g-C3N4) into a three-dimensional hierarchical porous graphene assembly to achieve a synergistic combination of confinement and catalyzation of polysulfides. The porous g-C3N4 nanosheets in situ formed inside the graphene network afford a highly accessible surface to catalyze the transformation of polysulfides, and the hierarchical porous graphene-assembled carbon can function as a conductive network and provide appropriate space for g-C3N4 catalysis in the sulfur cathode. Thus, this hybrid can effectively improve sulfur utilization and block the dissolution of polysulfides, achieving excellent cycling performance for sulfur cathodes in lithium-sulfur batteries.
Keywordslithium-sulfur batteries lithium polysulfide graphitic carbon nitride (g-C3N4) graphene catalytic conversion
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This work was supported by the National Basic Research Program of China (No. 2014CB932400). Q.-H. Y. is grateful for the support of the National Natural Science Foundation of China (No. 51525204) and Y. T. acknowledges support from the National Natural Science Foundation of China (No. 51702229).
- Zhou, T. H.; Lv, W.; Li, J.; Zhou, G. M.; Zhao, Y.; Fan, S. X.; Liu, B. L.; Li, B. H.; Kang, F. Y.; Yang, Q. H. Twinborn TiO2-TiN heterostructures enabling smooth trapping-diffusionconversion of polysulfides towards ultralong life lithiumsulfur batteries. Energy Environ. Sci. 2017, 10, 1694–1703.CrossRefGoogle Scholar
- Yu, H. J.; Shang, L.; Bian, T.; Shi, R.; Waterhouse, G. I. N.; Zhao, Y. F.; Zhou, C.; Wu, L. Z.; Tung, C. H.; Zhang, T. R. Nitrogen-doped porous carbon nanosheets templated from g-C3N4 as metal-free electrocatalysts for efficient oxygen reduction reaction. Adv. Mater. 2016, 28, 5080–5086.CrossRefGoogle Scholar
- Hou, Y.; Wen, Z. H.; Cui, S. M.; Feng, X. L.; Chen, J. H. Strongly coupled ternary hybrid aerogels of N-deficient porous graphitic-C3N4 nanosheets/N-doped graphene/NiFe-layered double hydroxide for solar-driven photoelectrochemical water oxidation. Nano Lett. 2016, 16, 2268–2277.CrossRefGoogle Scholar