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
Tin phosphide(Sn_(4)P_(3))is a promising anode material for sodium-ion batteries because of its relatively large theoretical capacity,appropriate Na^(+) alloying potential,and good cyclic stability.Herein,the Sn_(4)P_...Tin phosphide(Sn_(4)P_(3))is a promising anode material for sodium-ion batteries because of its relatively large theoretical capacity,appropriate Na^(+) alloying potential,and good cyclic stability.Herein,the Sn_(4)P_(3) embedded into a carbon matrix with good rate performance and long cycle life is reported.The Sn_(4)P_(3)-C composite exhibits excellent rate performance(540 mAh g^(-1) at 5 A g^(-1))and the highest reversible capacity(844 mAh g^(-1) at 0.5 A ^(g-1))among Sn4P3-based anodes reported so far.Its reversible capacity is as high as 705 mAh g^(-1) even after 100 cycles at 0.5 A g^(-1).Besides,its initial Coulomb efficiency can reach 85.6%,with the average Coulomb efficiency exceeding 99.75%from the 3rd to 100th cycles.Na_(2)C_(6)O_(6) is firstly used as a cathode when Sn_(4)P_(3) acts as anode,and the Na-Sn_(4)P_(3)-C//Na_(2)C_(6)O_(6) full cell shows excellent electrochemical performance.These results demonstrate that the Sn_(4)P_(3)-C composite prepared in this work displays high-rate capability and superior cyclic performance,and thus is a potential anode for sodium ion batteries.展开更多
The potential application of high-capacity Sn_(4)P_(3)anode for potassium-ion batteries(PIBs)is hindered by the poor cycle stability mainly rooted from the huge volume changes upon cycling and low electronic conduc-ti...The potential application of high-capacity Sn_(4)P_(3)anode for potassium-ion batteries(PIBs)is hindered by the poor cycle stability mainly rooted from the huge volume changes upon cycling and low electronic conduc-tivity.To address the above issues,sandwich-like struc-tured Sn_(4)P_(3)/Ti_(3)C_(2)T_(x)was designed and synthesized as anode material for PIBs.As a result,Sn_(4)P_(3)/Ti_(3)C_(2)T_(x)pre-sents superior cycle stability(retains a capacity of 103.2 mAh·g^(-1)even after 300 cycles at 1000 mA·g^(-1))and rate capability(delivers 60.7 mAh·g^(-1)at high current density of 2000 mA·g^(-1)).The excellent electrochemical perfor-mance of sandwich-like structured Sn_(4)P_(3)/Ti_(3)C_(2)Tx is orig-inated from the synergistic effect between Sn_(4)P_(3)and Ti_(3)C_(2)T_(x),where Ti_(3)C_(2)T_(x)acts as a conductive matrix to facilitate electron transfer and buffer the volume change of Sn_(4)P_(3)particles upon cycling,while Sn_(4)P_(3)serves as pillars to prevent the collapse and stacking of Ti_(3)C_(2)T_(x)sheets.Moreover,significant capacitive contribution is demonstrated as a major contributor to the excellent rate capability.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
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。
基金supported by Guizhou Provincial Science and Technology Foundation,China(No.[2019]1229)the National Natural Science Foundation of China(Nos.21361007,51776046)。
文摘通过高温固相技术合成Ho^(3+)和Yb^(3+)共掺杂La_(7)P_(3)O_(18)上转换荧光粉。XRD结果表明,合成样品是空间群为P21/n的单斜结构的La_(7)P_(3)O_(18)晶体和少量La PO4晶体的混合物。紫外可见漫反射光谱结果证实La_(7)P_(3)O_(18)晶体是一种光学带隙为4.10 e V的间接半导体。经980 nm激光激发,Ho^(3+)和Yb^(3+)共掺杂La_(7)P_(3)O_(18)荧光粉发射出Ho^(3+)离子特征的蓝色(486 nm)、绿色(550 nm)和红色(661 nm)特征峰,其中,661 nm处发射峰在样品上转换发光光谱中占主导地位。此外,随着Ho^(3+)和Yb^(3+)掺杂量的增加,样品上转换发光强度先增大后减小。当Ho^(3+)和Yb^(3+)的掺杂量分别达到1%和10%(摩尔分数)时,样品出现浓度猝灭现象,其机制为电四极-电四极相互作用。泵浦功率和发光强度关系表明,样品的绿光和红光发射均源于双光子吸收过程激发。Ho^(3+)和Yb^(3+)共掺杂La_(7)P_(3)O_(18)晶体上转换发光色坐标位于橙红色区域。
基金supported by the Elements Strategy Initiative for Catalysts and Batteries,MEXT,Japan(Grant Number JPMXP0112101003).
文摘Tin phosphide(Sn_(4)P_(3))is a promising anode material for sodium-ion batteries because of its relatively large theoretical capacity,appropriate Na^(+) alloying potential,and good cyclic stability.Herein,the Sn_(4)P_(3) embedded into a carbon matrix with good rate performance and long cycle life is reported.The Sn_(4)P_(3)-C composite exhibits excellent rate performance(540 mAh g^(-1) at 5 A g^(-1))and the highest reversible capacity(844 mAh g^(-1) at 0.5 A ^(g-1))among Sn4P3-based anodes reported so far.Its reversible capacity is as high as 705 mAh g^(-1) even after 100 cycles at 0.5 A g^(-1).Besides,its initial Coulomb efficiency can reach 85.6%,with the average Coulomb efficiency exceeding 99.75%from the 3rd to 100th cycles.Na_(2)C_(6)O_(6) is firstly used as a cathode when Sn_(4)P_(3) acts as anode,and the Na-Sn_(4)P_(3)-C//Na_(2)C_(6)O_(6) full cell shows excellent electrochemical performance.These results demonstrate that the Sn_(4)P_(3)-C composite prepared in this work displays high-rate capability and superior cyclic performance,and thus is a potential anode for sodium ion batteries.
基金financially supported by the National Natural Science Foundation of China (No. 52100084)Shenzhen Natural Science Fund (No. GXWD2020123015542700320200824094017001)
文摘The potential application of high-capacity Sn_(4)P_(3)anode for potassium-ion batteries(PIBs)is hindered by the poor cycle stability mainly rooted from the huge volume changes upon cycling and low electronic conduc-tivity.To address the above issues,sandwich-like struc-tured Sn_(4)P_(3)/Ti_(3)C_(2)T_(x)was designed and synthesized as anode material for PIBs.As a result,Sn_(4)P_(3)/Ti_(3)C_(2)T_(x)pre-sents superior cycle stability(retains a capacity of 103.2 mAh·g^(-1)even after 300 cycles at 1000 mA·g^(-1))and rate capability(delivers 60.7 mAh·g^(-1)at high current density of 2000 mA·g^(-1)).The excellent electrochemical perfor-mance of sandwich-like structured Sn_(4)P_(3)/Ti_(3)C_(2)Tx is orig-inated from the synergistic effect between Sn_(4)P_(3)and Ti_(3)C_(2)T_(x),where Ti_(3)C_(2)T_(x)acts as a conductive matrix to facilitate electron transfer and buffer the volume change of Sn_(4)P_(3)particles upon cycling,while Sn_(4)P_(3)serves as pillars to prevent the collapse and stacking of Ti_(3)C_(2)T_(x)sheets.Moreover,significant capacitive contribution is demonstrated as a major contributor to the excellent rate capability.
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.
