A pseudo AB 2 monomer,N-(2-acetoxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 2),was synthesized by two steps.Firstly the ring-opening reaction of 1,2,4-benzenetricarboxylic anhydride was carried out with ethan...A pseudo AB 2 monomer,N-(2-acetoxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 2),was synthesized by two steps.Firstly the ring-opening reaction of 1,2,4-benzenetricarboxylic anhydride was carried out with ethanolamine resulting in N-(2-hydroxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 1),and then F 1 was acetylized by acetic anhydride to afford F 2.The yields for F 1 and F 2 are 90% and 84.5%,respectively.By bulk polycondensation of F 2 catalyzed by Zn(OAc) 2,a novel hyperbranched poly(ester-amide) was effectively prepared in a yield of 92%.The structure of the product was characterized by mean of IR, 1H-NMR,DSC and TGA.The obtained polymer has good thermal properties as expected.The effect of the polymer on the rheological behavior of polycarbonate (PC) was studied by using Haake Rheomix 600.It was shown that the torque of melt PC was reduced by 70% with the addition of 5wt% of the obtained hyperbranched poly(ester-amide).展开更多
Sodium-ion batteries(SIBs)with advantages of abundant resource and low cost have emerged as promising candidates for the next-generation energy storage systems.However,safety issues existing in electrolytes,anodes,and...Sodium-ion batteries(SIBs)with advantages of abundant resource and low cost have emerged as promising candidates for the next-generation energy storage systems.However,safety issues existing in electrolytes,anodes,and cathodes bring about frequent accidents regarding battery fires and explosions and impede the development of high-performance SIBs.Therefore,safety analysis and high-safety battery design have become prerequisites for the development of advanced energy storage systems.The reported reviews that only focus on a specific issue are difficult to provide overall guidance for building high-safety SIBs.To overcome the limitation,this review summarizes the recent research progress from the perspective of key components of SIBs for the first time and evaluates the characteristics of various improvement strategies.By orderly analyzing the root causes of safety problems associated with different components in SIBs(including electrolytes,anodes,and cathodes),corresponding improvement strategies for each component were discussed systematically.In addition,some noteworthy points and perspectives including the chain reaction between security issues and the selection of improvement strategies tailored to different needs have also been proposed.In brief,this review is designed to deepen our understanding of the SIBs safety issues and provide guidance and assistance for designing high-safety SIBs.展开更多
Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,wh...Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,which is attributed to lower count of slip systems associated with the hcp crystal structure.To address these limitations,several new magnesium alloys and also many processing strategies have been developed and reported in the literature.ZE41 Mg is an alloy with significant quantities of zinc(Zn)and rare earth(RE)elements and has emerged as a promising material for aerospace,automotive,electronics,biomedical and many other industries.To make this alloy more competitive and viable,it should possess better mechanical and corrosion properties.Hence,the current paper reviews the effect of bulk mechanical processing on grain refinement,microstructural modification,and corresponding changes in the mechanical behaviour of ZE41Mg alloy.Further,the effect of various surface modification techniques on altering the surface microstructure and surface properties such as wear and corrosion are also briefly summarized and presented.This review also discusses the challenges and the future perspectives in developing high-performing ZE41 Mg alloys.展开更多
The exploration of advanced materials through rational structure/phase design is the key to develop highperformance lithium-ion capacitors(LICs).However,high complexity of material preparation and difficulty in quanti...The exploration of advanced materials through rational structure/phase design is the key to develop highperformance lithium-ion capacitors(LICs).However,high complexity of material preparation and difficulty in quantity production largely hinder the further development.Herein,Cu_(5)FeS_(4-x)/C(CFS@C)heterojunction with rich sulfur vacancies has successfully achieved from natural bornite,presenting low costeffective and bulk-production prospect.Density functional theory(DFT)calculations indicate that rich vacancies in bulk phase can decrease band gap of bornite and thus improve its intrinsic electron conductivity,as well as the heterojunction spontaneously evokes a built-in electric field between its interfacial region,largely reducing the migration barrier from 1.27 e V to 0.75 e V.Benefited from these merits,the CFS@C electrodes deliver outperformed lithium storage performance,e.g.,high reversible capacity(822.4m Ah/g at 0.1 A/g),excellent cycling stability(up to 820 cycles at 2 A/g and 540 cycles at 5 A/g with respective capacity retention of over or nearly 100%).With CFS@C as anode and porous carbon nanosheets(PCS)as cathode,the assembled CFS@C//PCS LIC full cells exhibit high energy/power density characteristics of 139.2 Wh/kg at 2500 W/kg.This work is expected to offer significant insights into structure modifications/devising toward natural minerals for advanced energy-storage systems.展开更多
文摘A pseudo AB 2 monomer,N-(2-acetoxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 2),was synthesized by two steps.Firstly the ring-opening reaction of 1,2,4-benzenetricarboxylic anhydride was carried out with ethanolamine resulting in N-(2-hydroxyl ethyl)-N-(2′,4′-dicarboxylic benzoyl) amine (F 1),and then F 1 was acetylized by acetic anhydride to afford F 2.The yields for F 1 and F 2 are 90% and 84.5%,respectively.By bulk polycondensation of F 2 catalyzed by Zn(OAc) 2,a novel hyperbranched poly(ester-amide) was effectively prepared in a yield of 92%.The structure of the product was characterized by mean of IR, 1H-NMR,DSC and TGA.The obtained polymer has good thermal properties as expected.The effect of the polymer on the rheological behavior of polycarbonate (PC) was studied by using Haake Rheomix 600.It was shown that the torque of melt PC was reduced by 70% with the addition of 5wt% of the obtained hyperbranched poly(ester-amide).
基金supported by the Natural Science Foundation of China(52272188,U22A20227)the Natural Science Foundation of Beijing(2232025)+2 种基金the Natural Science Foundation of Chongqing(2022NSCQ-MSX2179)the Department of Science and Technology of Henan Province(Z20221343029)the Experimental Center of Advanced Materials in Beijing Institute of Technology。
文摘Sodium-ion batteries(SIBs)with advantages of abundant resource and low cost have emerged as promising candidates for the next-generation energy storage systems.However,safety issues existing in electrolytes,anodes,and cathodes bring about frequent accidents regarding battery fires and explosions and impede the development of high-performance SIBs.Therefore,safety analysis and high-safety battery design have become prerequisites for the development of advanced energy storage systems.The reported reviews that only focus on a specific issue are difficult to provide overall guidance for building high-safety SIBs.To overcome the limitation,this review summarizes the recent research progress from the perspective of key components of SIBs for the first time and evaluates the characteristics of various improvement strategies.By orderly analyzing the root causes of safety problems associated with different components in SIBs(including electrolytes,anodes,and cathodes),corresponding improvement strategies for each component were discussed systematically.In addition,some noteworthy points and perspectives including the chain reaction between security issues and the selection of improvement strategies tailored to different needs have also been proposed.In brief,this review is designed to deepen our understanding of the SIBs safety issues and provide guidance and assistance for designing high-safety SIBs.
文摘Magnesium(Mg)alloys are generally used in light-weight structural applications due to their higher specific strength.However,the usage of these Mg alloys is limited due to their poor formability at room temperature,which is attributed to lower count of slip systems associated with the hcp crystal structure.To address these limitations,several new magnesium alloys and also many processing strategies have been developed and reported in the literature.ZE41 Mg is an alloy with significant quantities of zinc(Zn)and rare earth(RE)elements and has emerged as a promising material for aerospace,automotive,electronics,biomedical and many other industries.To make this alloy more competitive and viable,it should possess better mechanical and corrosion properties.Hence,the current paper reviews the effect of bulk mechanical processing on grain refinement,microstructural modification,and corresponding changes in the mechanical behaviour of ZE41Mg alloy.Further,the effect of various surface modification techniques on altering the surface microstructure and surface properties such as wear and corrosion are also briefly summarized and presented.This review also discusses the challenges and the future perspectives in developing high-performing ZE41 Mg alloys.
基金supported by the National Natural Science Foundation of China(Nos.52004338,22378431)Hunan Provincial Natural Science Foundation(Nos.2022JJ20075,2023JJ40210)+1 种基金Scientific Research Fund of Hunan Provincial Education Department(No.21B0017)Central South University Innovation-Driven Research Programme(No.2023CXQD008)。
文摘The exploration of advanced materials through rational structure/phase design is the key to develop highperformance lithium-ion capacitors(LICs).However,high complexity of material preparation and difficulty in quantity production largely hinder the further development.Herein,Cu_(5)FeS_(4-x)/C(CFS@C)heterojunction with rich sulfur vacancies has successfully achieved from natural bornite,presenting low costeffective and bulk-production prospect.Density functional theory(DFT)calculations indicate that rich vacancies in bulk phase can decrease band gap of bornite and thus improve its intrinsic electron conductivity,as well as the heterojunction spontaneously evokes a built-in electric field between its interfacial region,largely reducing the migration barrier from 1.27 e V to 0.75 e V.Benefited from these merits,the CFS@C electrodes deliver outperformed lithium storage performance,e.g.,high reversible capacity(822.4m Ah/g at 0.1 A/g),excellent cycling stability(up to 820 cycles at 2 A/g and 540 cycles at 5 A/g with respective capacity retention of over or nearly 100%).With CFS@C as anode and porous carbon nanosheets(PCS)as cathode,the assembled CFS@C//PCS LIC full cells exhibit high energy/power density characteristics of 139.2 Wh/kg at 2500 W/kg.This work is expected to offer significant insights into structure modifications/devising toward natural minerals for advanced energy-storage systems.
