Tin phosphide(Sn_(x)P_(y))is an anode for sodium-ion batteries resulting from its exceptionally high theoretical capacity in future.Nevertheless,its application will be hindered by significant volume expansion during ...Tin phosphide(Sn_(x)P_(y))is an anode for sodium-ion batteries resulting from its exceptionally high theoretical capacity in future.Nevertheless,its application will be hindered by significant volume expansion during charge discharge cycles and poor electrical conductivity.This study employs a Sn-based metal-organic framework(Sn-MOF)as a precursor for synthesizing tin phosphide nanoparticles.Then Solidago Canadensis L.,commonly known as Canadian Goldenrod,is utilized as a biomass carbon carrier to form a composite with tin phosphide nanoparticles.The biomass derived porous carbon provides additional sodium ion storage sites and serves as a structural scaffold that constrains the volumetric expansion of tin phosphide,thereby enhancing the material’s stability.The fabricated composite exhibits superior electrode electrochemical performance for sodium-ion batteries.It retains a high capacity(489.5 mA·h/g)after 100 cycles at 0.2 A/g.Even after 500 cycles at a high current density of 2 A/g,it still maintains a stable reversible capacity.This study offers a comprehensive exploration of innovative design strategies essential for the development of novel anode materials,paving the way for more sustainable and efficient sodium-ion-based energy storage systems.展开更多
为合理地分析超声速发动机在起降着陆(landing and take-off,LTO)循环中的污染物排放特性,构建了基于CFM56-7B27核心机的超声速发动机模型。通过建立排放计算模型计算了LTO污染物排放指数(emission index,EI),并分析了其排放特性;研究...为合理地分析超声速发动机在起降着陆(landing and take-off,LTO)循环中的污染物排放特性,构建了基于CFM56-7B27核心机的超声速发动机模型。通过建立排放计算模型计算了LTO污染物排放指数(emission index,EI),并分析了其排放特性;研究爬升和慢车阶段污染物排放特性对LTO超声速模式标准设定的影响,进而确定更具代表性的LTO超声速模式标准。分析结果表明:不同LTO阶段的推力设置(thrust setting,TS)和模式时间(time in mode,TIM)对污染物排放特性的影响存在差异性;在LTO标准研究方面,60%额定推力、2 min模式时间的爬升点氮氧化物的排放质量/额定推力更接近于超声速爬升轨迹,慢车点TS在不低于10%额定推力时更能满足污染物(一氧化碳、未燃烧碳氢)排放特性所限制的燃烧效率要求,因此以60%额定推力、2 min模式时间作为LTO超声速模式爬升点标准、以TS不低于10%额定推力作为LTO超声速模式慢车点标准更为合理。展开更多
开发高量子效率、高热稳定性和高化学稳定性的窄带蓝色荧光粉是广色域背光显示技术领域急需解决的难题.然而,最近报道的Eu^(2+)激活的窄带蓝色荧光粉主要集中在UCr_(4)C_(4)构型的基质材料中,而且化学稳定性往往较差.本工作采用高温固...开发高量子效率、高热稳定性和高化学稳定性的窄带蓝色荧光粉是广色域背光显示技术领域急需解决的难题.然而,最近报道的Eu^(2+)激活的窄带蓝色荧光粉主要集中在UCr_(4)C_(4)构型的基质材料中,而且化学稳定性往往较差.本工作采用高温固相法合成了一种硼磷酸盐Li_(3)Cs_(2)Sr_(2-x)B_(3)P_(6)O2_(4:x)Eu^(2+)(0.005≤x≤0.03,下文简写成LCSBPO:_(x)Eu^(2+))窄带蓝色(半峰宽FWHM=34 nm,λem=432 nm)荧光粉.Eu^(2+)离子的最佳掺杂量为0.02.LCSBPO:x Eu^(2+)荧光粉中存在两个Eu^(2+)离子荧光中心,分别对应占据在Sr(1)和Sr(2)两个格位的Eu2+离子.此外,LCSBPO:0.02Eu^(2+)荧光粉还具有较高的内/外量子效率(62.9%/16.8%)、出众的热稳定性(86.6%@150℃)、超高的色纯度(99%)和优异的化学稳定性(在去离子水中浸泡1个月后其发射强度能维持在93%).在25~250℃温度范围内,LCSBPO:0.02Eu^(2+)荧光粉还表现出优异的色度稳定性(Δx=0.0014,Δy=0.0024;4×10^(-4)≤ΔC≤9.7×10^(-3)).由LCSBPO:0.02Eu^(2+)蓝光荧光粉、商用β-Si Al ON:Eu^(2+)绿色荧光粉、商用K_(2)SiF_(6):Mn^(4+)红色荧光粉和365 nm的LED芯片封装的白光发光二极管(WLED)能发射出明亮的白光,且该WLED在CIE 1931色坐标中的色域面积可以达到NTSC(National Television System Committee)标准色域面积的83%.上述发现证明本工作报道的LCSBPO:0.02Eu^(2+)窄带蓝色荧光粉在WLED技术中有良好的潜在应用前景.展开更多
Developing reliable and efficient anode materials is essential for the successfully practical application of sodium-ion batteries.Herein,employing a straightforward and rapid chemical vapor deposition technique,two-di...Developing reliable and efficient anode materials is essential for the successfully practical application of sodium-ion batteries.Herein,employing a straightforward and rapid chemical vapor deposition technique,two-dimensional layered ternary indium phosphorus sulfide(In_(2)P_(3)S_(9)) nanosheets are prepared.The layered structure and ternary composition of the In_(2)P_(3)S_(9) electrode result in impressive electrochemical performance,including a high reversible capacity of 704 mA h g^(-1) at 0.1 A g^(-1),an outstanding rate capability with 425 mA h g^(-1) at 5 A g^(-1),and an exceptional cycling stability with a capacity retention of88% after 350 cycles at 1 A g^(-1).Furthermore,sodium-ion full cell also affords a high capacity of 308 and114 mA h g^(-1) at 0.1 and 5 A g^(-1).Ex-situ X-ray diffraction and ex-situ high-resolution transmission electron microscopy tests are conducted to investigate the underlying Na-storage mechanism of In_(2)P_(3)S_(9).The results reveal that during the first cycle,the P-S bond is broken to form the elemental P and In_(2)S_(3),collectively contributing to a remarkably high reversible specific capacity.The excellent electrochemical energy storage results corroborate the practical application potential of In_(2)P_(3)S_(9) for sodium-ion batteries.展开更多
Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and on...Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.展开更多
文摘Tin phosphide(Sn_(x)P_(y))is an anode for sodium-ion batteries resulting from its exceptionally high theoretical capacity in future.Nevertheless,its application will be hindered by significant volume expansion during charge discharge cycles and poor electrical conductivity.This study employs a Sn-based metal-organic framework(Sn-MOF)as a precursor for synthesizing tin phosphide nanoparticles.Then Solidago Canadensis L.,commonly known as Canadian Goldenrod,is utilized as a biomass carbon carrier to form a composite with tin phosphide nanoparticles.The biomass derived porous carbon provides additional sodium ion storage sites and serves as a structural scaffold that constrains the volumetric expansion of tin phosphide,thereby enhancing the material’s stability.The fabricated composite exhibits superior electrode electrochemical performance for sodium-ion batteries.It retains a high capacity(489.5 mA·h/g)after 100 cycles at 0.2 A/g.Even after 500 cycles at a high current density of 2 A/g,it still maintains a stable reversible capacity.This study offers a comprehensive exploration of innovative design strategies essential for the development of novel anode materials,paving the way for more sustainable and efficient sodium-ion-based energy storage systems.
文摘为合理地分析超声速发动机在起降着陆(landing and take-off,LTO)循环中的污染物排放特性,构建了基于CFM56-7B27核心机的超声速发动机模型。通过建立排放计算模型计算了LTO污染物排放指数(emission index,EI),并分析了其排放特性;研究爬升和慢车阶段污染物排放特性对LTO超声速模式标准设定的影响,进而确定更具代表性的LTO超声速模式标准。分析结果表明:不同LTO阶段的推力设置(thrust setting,TS)和模式时间(time in mode,TIM)对污染物排放特性的影响存在差异性;在LTO标准研究方面,60%额定推力、2 min模式时间的爬升点氮氧化物的排放质量/额定推力更接近于超声速爬升轨迹,慢车点TS在不低于10%额定推力时更能满足污染物(一氧化碳、未燃烧碳氢)排放特性所限制的燃烧效率要求,因此以60%额定推力、2 min模式时间作为LTO超声速模式爬升点标准、以TS不低于10%额定推力作为LTO超声速模式慢车点标准更为合理。
文摘开发高量子效率、高热稳定性和高化学稳定性的窄带蓝色荧光粉是广色域背光显示技术领域急需解决的难题.然而,最近报道的Eu^(2+)激活的窄带蓝色荧光粉主要集中在UCr_(4)C_(4)构型的基质材料中,而且化学稳定性往往较差.本工作采用高温固相法合成了一种硼磷酸盐Li_(3)Cs_(2)Sr_(2-x)B_(3)P_(6)O2_(4:x)Eu^(2+)(0.005≤x≤0.03,下文简写成LCSBPO:_(x)Eu^(2+))窄带蓝色(半峰宽FWHM=34 nm,λem=432 nm)荧光粉.Eu^(2+)离子的最佳掺杂量为0.02.LCSBPO:x Eu^(2+)荧光粉中存在两个Eu^(2+)离子荧光中心,分别对应占据在Sr(1)和Sr(2)两个格位的Eu2+离子.此外,LCSBPO:0.02Eu^(2+)荧光粉还具有较高的内/外量子效率(62.9%/16.8%)、出众的热稳定性(86.6%@150℃)、超高的色纯度(99%)和优异的化学稳定性(在去离子水中浸泡1个月后其发射强度能维持在93%).在25~250℃温度范围内,LCSBPO:0.02Eu^(2+)荧光粉还表现出优异的色度稳定性(Δx=0.0014,Δy=0.0024;4×10^(-4)≤ΔC≤9.7×10^(-3)).由LCSBPO:0.02Eu^(2+)蓝光荧光粉、商用β-Si Al ON:Eu^(2+)绿色荧光粉、商用K_(2)SiF_(6):Mn^(4+)红色荧光粉和365 nm的LED芯片封装的白光发光二极管(WLED)能发射出明亮的白光,且该WLED在CIE 1931色坐标中的色域面积可以达到NTSC(National Television System Committee)标准色域面积的83%.上述发现证明本工作报道的LCSBPO:0.02Eu^(2+)窄带蓝色荧光粉在WLED技术中有良好的潜在应用前景.
基金Financial supports from the National Natural Science Foundation of China(22265018 and 21961019)the Key Project of Natural Science Foundation of Jiangxi Province(20232ACB204010)。
文摘Developing reliable and efficient anode materials is essential for the successfully practical application of sodium-ion batteries.Herein,employing a straightforward and rapid chemical vapor deposition technique,two-dimensional layered ternary indium phosphorus sulfide(In_(2)P_(3)S_(9)) nanosheets are prepared.The layered structure and ternary composition of the In_(2)P_(3)S_(9) electrode result in impressive electrochemical performance,including a high reversible capacity of 704 mA h g^(-1) at 0.1 A g^(-1),an outstanding rate capability with 425 mA h g^(-1) at 5 A g^(-1),and an exceptional cycling stability with a capacity retention of88% after 350 cycles at 1 A g^(-1).Furthermore,sodium-ion full cell also affords a high capacity of 308 and114 mA h g^(-1) at 0.1 and 5 A g^(-1).Ex-situ X-ray diffraction and ex-situ high-resolution transmission electron microscopy tests are conducted to investigate the underlying Na-storage mechanism of In_(2)P_(3)S_(9).The results reveal that during the first cycle,the P-S bond is broken to form the elemental P and In_(2)S_(3),collectively contributing to a remarkably high reversible specific capacity.The excellent electrochemical energy storage results corroborate the practical application potential of In_(2)P_(3)S_(9) for sodium-ion batteries.
基金National Natural Science Foundation of China,Grant/Award Numbers:21972108,U20A20249,U22A20438Changzhou Science and Technology Bureau,Grant/Award Number:CM20223017Innovation and Technology Commission(ITC)of Hong Kong,The Innovation&Technology Fund(ITF)with Project No.ITS/126/21。
文摘Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.
