Lithium-sulfur batteries are considered as one of the potential solutions as integrating renewable energy systems for large-scale energy storage because of their high theoretical energy density(2600 Wh·kg^(-1))an...Lithium-sulfur batteries are considered as one of the potential solutions as integrating renewable energy systems for large-scale energy storage because of their high theoretical energy density(2600 Wh·kg^(-1))and specific capacity(1675 mAh·g^(-1)).Currently,various strategies have been proposed to overcome the technical barriers,e.g.,“shuttle effect”,capacity decay and volumetric change,which impede the successful commercialization of lithium-sulfur batteries.This paper reviews the applications of metal nitrides as the cathode hosts for high-performance lithium-sulfur batteries,summa-rizes the design strategies of different host materials,and discusses the relationship between the properties of metal nitrides and their electrochemical performances.Finally,reasonable suggestions for the design and development of metal nitrides,along with ideas to promote future breakthroughs,are proposed.We hope that this review could attract more attention to metal nitrides and their derivatives,and further promote the electrochemical performance of lithium-sulfur batteries.展开更多
Shuttle effect,poor conductivity and large volume expansion are the main factors that hinder the practical application of sulfur cathodes.Currently,rational structure designing of carbon-based sulfur hosts is the most...Shuttle effect,poor conductivity and large volume expansion are the main factors that hinder the practical application of sulfur cathodes.Currently,rational structure designing of carbon-based sulfur hosts is the most effective strategy to address the above issues.However,the preparation process of carbon-based sulfur hosts is usually complex and costly.Therefore,it is necessary to develop an efficient and cost-effective method to fabricate carbon hosts for high-performance sulfur cathodes.Herein,we reported the fabrication of a bio-derived nitrogen doped porous carbon materials(BNPC)via a molten-salt method for high performance sulfur cathodes.The long-range-ordered honeycomb structure of BNPC is favorable for the trapping of polysulfide(PS)species and accommodates the volumetric variation of sulfur during cycling,while the high graphitization degree of BNPC favors the redox kinetics of sulfur cathodes.Moreover,the nitrogen doping content not only enhances the electrical conductivity of BNPC,but also provides ample anchoring sites for the immobilization of PS,which plays a key role in suppressing the shuttle effect.As a result,the S@BNPC cathode exhibits a high initial specific capacity of 1189.4 mA·h/g at 0.2C.After 300 cycles,S@BNPC still maintains a capacity of 703.2 mA·h/g which corresponds to a fading rate of 0.13%per cycle after the second cycle.This work offers vast opportunities for the large-scale application of high performance carbon-based sulfur hosts.展开更多
The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensi...The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensively developed in this HP belt. Compared with normal mid-ocean ridge basalt(N-MORB), the high-pressure veins and host rocks are enriched in light rare earth elements(LREE) and incompatible elements. But high-pressure veins show a larger variation than host rocks in total REE abundance. On the trace element spidergram, all the samples are enriched in incompatible elements and show strong positive Pb anomaly relative to N-MORB. The array tendency lines of plots of the HP rocks have apparent slopes on diagram of m(Sr) vs m(Sr)/m(Zr), m(Li) vs m(Li)/m(Y) and (m(Ce)) vs m(Ce)/m(Pb), which indicates that the enrichment in LREE and incompatible elements relative to N-MORB of the HP-metamorphic rocks from western Tianshan is not attributed to magma evolution process of the protolith. High field strength elements, such as Nb, Ta, Ti, Zr and Hf, do not show negative anomaly relative to N-MORB, which is dissimilar to that of island arc basalts. Therefore, the enrichment in LREE and incompatible elements of the HP rocks is not attributed to the enrichment of the source of the protolith. The mass ratios of Rb to Ba, Ce to Pb, Nb to U and Ta to U of high-pressure veins and host rocks are intermediate of mid-ocean ridge basalt or oceanic island basalt and continental crust. The fluids in western Tianshan paleosubduction zones are mixtures of two sources, dehydration or devolatilization of host rocks and of subducted sediments.展开更多
Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition, attack and subseque...Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition, attack and subsequent penetration and killing of the host. Investigations on the underlying events revealed that Trichoderma responds to multiple signals from the host (e.g. lectins or other ligands such as low molecular weight components released from the host’s cell wall) and host attack is accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics. Degradation of the cell wall of the host fungus is-besides glucanases and proteases-mainly achieved by chitinases. In vivo studies showed that the ech42 gene (encoding endochitinase 42) is expressed before physical contact of Trichoderma with its host, probably representing one of the earliest events in mycoparasitism, whereas Nag1 (N-acetylglucosaminidase) plays a key role in the general induction of the chitinolytic enzyme system of T. atroviride . Investigations on the responsible signal transduction pathways of T. atroviride led to the isolation of several genes encoding key components of the cAMP and MAP kinase signaling pathways, as alpha and β subunits of heterotrimeric G proteins, the regulatory subunit of cAMP-dependent protein kinase, adenylate cyclase, and three MAP kinases. Analysis of knockout mutants, generated by Agrobacterium-mediated transformation, revealed that at least two alpha-subunits of heterotrimeric G proteins are participating in mycoparasitism-related signal transduction. The Tga1 G alpha subunit was shown to be involved in mycoparasitism-related processes such as chitinase expression and overproduction of toxic secondary metabolites, whereas Tga3 was found to be completely avirulent showing defects in chitinase formation and host recognition.展开更多
文摘Lithium-sulfur batteries are considered as one of the potential solutions as integrating renewable energy systems for large-scale energy storage because of their high theoretical energy density(2600 Wh·kg^(-1))and specific capacity(1675 mAh·g^(-1)).Currently,various strategies have been proposed to overcome the technical barriers,e.g.,“shuttle effect”,capacity decay and volumetric change,which impede the successful commercialization of lithium-sulfur batteries.This paper reviews the applications of metal nitrides as the cathode hosts for high-performance lithium-sulfur batteries,summa-rizes the design strategies of different host materials,and discusses the relationship between the properties of metal nitrides and their electrochemical performances.Finally,reasonable suggestions for the design and development of metal nitrides,along with ideas to promote future breakthroughs,are proposed.We hope that this review could attract more attention to metal nitrides and their derivatives,and further promote the electrochemical performance of lithium-sulfur batteries.
基金Project(2018YFB0104300)supported by the National Key R&D Program of ChinaProject(51774150)supported by the National Natural Science Foundation of China
文摘Shuttle effect,poor conductivity and large volume expansion are the main factors that hinder the practical application of sulfur cathodes.Currently,rational structure designing of carbon-based sulfur hosts is the most effective strategy to address the above issues.However,the preparation process of carbon-based sulfur hosts is usually complex and costly.Therefore,it is necessary to develop an efficient and cost-effective method to fabricate carbon hosts for high-performance sulfur cathodes.Herein,we reported the fabrication of a bio-derived nitrogen doped porous carbon materials(BNPC)via a molten-salt method for high performance sulfur cathodes.The long-range-ordered honeycomb structure of BNPC is favorable for the trapping of polysulfide(PS)species and accommodates the volumetric variation of sulfur during cycling,while the high graphitization degree of BNPC favors the redox kinetics of sulfur cathodes.Moreover,the nitrogen doping content not only enhances the electrical conductivity of BNPC,but also provides ample anchoring sites for the immobilization of PS,which plays a key role in suppressing the shuttle effect.As a result,the S@BNPC cathode exhibits a high initial specific capacity of 1189.4 mA·h/g at 0.2C.After 300 cycles,S@BNPC still maintains a capacity of 703.2 mA·h/g which corresponds to a fading rate of 0.13%per cycle after the second cycle.This work offers vast opportunities for the large-scale application of high performance carbon-based sulfur hosts.
基金Preoject(2001CB409803) supported by the National Key Fundamental Research and Development Program of China
文摘The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensively developed in this HP belt. Compared with normal mid-ocean ridge basalt(N-MORB), the high-pressure veins and host rocks are enriched in light rare earth elements(LREE) and incompatible elements. But high-pressure veins show a larger variation than host rocks in total REE abundance. On the trace element spidergram, all the samples are enriched in incompatible elements and show strong positive Pb anomaly relative to N-MORB. The array tendency lines of plots of the HP rocks have apparent slopes on diagram of m(Sr) vs m(Sr)/m(Zr), m(Li) vs m(Li)/m(Y) and (m(Ce)) vs m(Ce)/m(Pb), which indicates that the enrichment in LREE and incompatible elements relative to N-MORB of the HP-metamorphic rocks from western Tianshan is not attributed to magma evolution process of the protolith. High field strength elements, such as Nb, Ta, Ti, Zr and Hf, do not show negative anomaly relative to N-MORB, which is dissimilar to that of island arc basalts. Therefore, the enrichment in LREE and incompatible elements of the HP rocks is not attributed to the enrichment of the source of the protolith. The mass ratios of Rb to Ba, Ce to Pb, Nb to U and Ta to U of high-pressure veins and host rocks are intermediate of mid-ocean ridge basalt or oceanic island basalt and continental crust. The fluids in western Tianshan paleosubduction zones are mixtures of two sources, dehydration or devolatilization of host rocks and of subducted sediments.
文摘Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition, attack and subsequent penetration and killing of the host. Investigations on the underlying events revealed that Trichoderma responds to multiple signals from the host (e.g. lectins or other ligands such as low molecular weight components released from the host’s cell wall) and host attack is accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics. Degradation of the cell wall of the host fungus is-besides glucanases and proteases-mainly achieved by chitinases. In vivo studies showed that the ech42 gene (encoding endochitinase 42) is expressed before physical contact of Trichoderma with its host, probably representing one of the earliest events in mycoparasitism, whereas Nag1 (N-acetylglucosaminidase) plays a key role in the general induction of the chitinolytic enzyme system of T. atroviride . Investigations on the responsible signal transduction pathways of T. atroviride led to the isolation of several genes encoding key components of the cAMP and MAP kinase signaling pathways, as alpha and β subunits of heterotrimeric G proteins, the regulatory subunit of cAMP-dependent protein kinase, adenylate cyclase, and three MAP kinases. Analysis of knockout mutants, generated by Agrobacterium-mediated transformation, revealed that at least two alpha-subunits of heterotrimeric G proteins are participating in mycoparasitism-related signal transduction. The Tga1 G alpha subunit was shown to be involved in mycoparasitism-related processes such as chitinase expression and overproduction of toxic secondary metabolites, whereas Tga3 was found to be completely avirulent showing defects in chitinase formation and host recognition.
