Lithium-sulfur batteries(LSBs) are regarded as a competitive next-generation energy storage device.However, their practical performance is seriously restricted due to the undesired polysulfides shuttling.Herein, a mul...Lithium-sulfur batteries(LSBs) are regarded as a competitive next-generation energy storage device.However, their practical performance is seriously restricted due to the undesired polysulfides shuttling.Herein, a multifunctional interlayer composed of paper-derived carbon(PC) scaffold, Fe3O4 nanoparticles,graphene, and graphite sheets is designed for applications in LSBs. The porous PC skeleton formed by the interweaving long-fibers not only facilitates fast transfer of Li ions and electrons but also provides a physical barrier for the polysulfide shuttling. The secondary Fe3O4@graphene component can reduce the polarization, boost the attachment of polysulfides, and promote the charging-discharging kinetics. The outer graphitic sheets layers benefit the interfacial electrochemistry and the utilization of S-containing species.The efficient obstruction of polysulfides diffusion is further witnessed via in situ ultraviolet-visible characterization and first-principles simulations. When 73% sulfur/commercial acetylene black is used as the cathode, the cell exhibits excellent capacity retention with high capacities at 0.5 C for 1000 cycles and even up to 10 C for 500 cycles, an ultrahigh rate capability up to 10 C(478 m Ah g-1), and a high arealsulfur loading of 8.05 mg cm-2. The strategy paves the way for developing multifunctional composites for LSBs with superior performance.展开更多
Carbon fibre-reinforced ultra-high temperature ceramics(UHTCs)are considered a class of promising materials for several applications,the most appealing ones being in the aerospace sector.Reinforcement is necessary to ...Carbon fibre-reinforced ultra-high temperature ceramics(UHTCs)are considered a class of promising materials for several applications,the most appealing ones being in the aerospace sector.Reinforcement is necessary to overcome the brittleness and low thermal shock resistance of ceramics and is often provided through the addition of carbon fibres or other carbon-based phases,such as nanotubes,graphene,and graphite.The present work is focused on the toughening of UHTCs through incorporation of 30-50 vol% thin,ordered graphite layers from conventional filter paper followed by hot pressing sintering.Cellulose filter paper was selected because it undergoes thermolysis with no melting stage forming a strong carbonaceous residue that can be used as toughener.Microstructure and mechanical properties of toughened composites were compared to those of other materials reinforced with short carbon fibres and the effect of different distribution of graphite was studied.Addition of graphite allowed toughness to be increased from 3−4 MPa·m^(1/2)(for unreinforced materials)to 5.1−5.5 MPa·m^(1/2),similar to results obtained with short fibre reinforcement.The high-temperature properties,such as strength and toughness as well as oxidation resistance at 1500℃,were also examined.展开更多
基金the financial supports provided by the National Natural Science Foundation of China (Nos. 21971145, 21601108)the Taishan Scholar Project Foundation of Shandong Province (ts20190908)+1 种基金the Natural Science Foundation of Shandong Province (ZR2019MB024)Young Scholars Program of Shandong University (2017WLJH15)。
文摘Lithium-sulfur batteries(LSBs) are regarded as a competitive next-generation energy storage device.However, their practical performance is seriously restricted due to the undesired polysulfides shuttling.Herein, a multifunctional interlayer composed of paper-derived carbon(PC) scaffold, Fe3O4 nanoparticles,graphene, and graphite sheets is designed for applications in LSBs. The porous PC skeleton formed by the interweaving long-fibers not only facilitates fast transfer of Li ions and electrons but also provides a physical barrier for the polysulfide shuttling. The secondary Fe3O4@graphene component can reduce the polarization, boost the attachment of polysulfides, and promote the charging-discharging kinetics. The outer graphitic sheets layers benefit the interfacial electrochemistry and the utilization of S-containing species.The efficient obstruction of polysulfides diffusion is further witnessed via in situ ultraviolet-visible characterization and first-principles simulations. When 73% sulfur/commercial acetylene black is used as the cathode, the cell exhibits excellent capacity retention with high capacities at 0.5 C for 1000 cycles and even up to 10 C for 500 cycles, an ultrahigh rate capability up to 10 C(478 m Ah g-1), and a high arealsulfur loading of 8.05 mg cm-2. The strategy paves the way for developing multifunctional composites for LSBs with superior performance.
基金supported by project CARBOSPACE“Ultra-refractory ceramic composites for Aerospace Defense Transport Energy”project ECOSISTER(National Recovery and Resilience Plan(NRRP),Mission 04 Component 2 Investment 1.5-NextGenerationEU,Call for tender n.3277 dated 30/12/2021,Award Number:0001052 dated 23/06/2022)project INFINITE“Liquid phase sintering of C fiber reinforced ultra-high temperature ceramics composites”.
文摘Carbon fibre-reinforced ultra-high temperature ceramics(UHTCs)are considered a class of promising materials for several applications,the most appealing ones being in the aerospace sector.Reinforcement is necessary to overcome the brittleness and low thermal shock resistance of ceramics and is often provided through the addition of carbon fibres or other carbon-based phases,such as nanotubes,graphene,and graphite.The present work is focused on the toughening of UHTCs through incorporation of 30-50 vol% thin,ordered graphite layers from conventional filter paper followed by hot pressing sintering.Cellulose filter paper was selected because it undergoes thermolysis with no melting stage forming a strong carbonaceous residue that can be used as toughener.Microstructure and mechanical properties of toughened composites were compared to those of other materials reinforced with short carbon fibres and the effect of different distribution of graphite was studied.Addition of graphite allowed toughness to be increased from 3−4 MPa·m^(1/2)(for unreinforced materials)to 5.1−5.5 MPa·m^(1/2),similar to results obtained with short fibre reinforcement.The high-temperature properties,such as strength and toughness as well as oxidation resistance at 1500℃,were also examined.