Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity.Density functional theory (DFT) and finite el...Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity.Density functional theory (DFT) and finite element simulations show that incorporating SO_(4)^(2-)into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge cycles.Consequently,the average Na+diffusion coefficient of Na_(3)V_(2)(PO_(4))_(1.95)(SO_(4))_(0.05)O_(2)F(VPS-1) is roughly double that of VP,leading to enhanced rate capability (80 C,75.5 mAh g^(-1)) and cycling stability (111.0 mAh g^(-1)capacity after 1000 cycles at 10 C current density) for VPS-1.VPS-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 min.The assembled VPS-1//SbSn/NPC full cell demonstrated stable cycling over 200 cycles at a high 5 C current,maintaining an average coulombic efficiency of 95.35%.展开更多
A new deep-ultraviolet(DUV)birefringent crystal,LiB_(5)O_(5)F_(2)(OH)_(4)(LBOFH),was designed and synthesized by a high-temperature solution method.Its structure features a[B_(5)O_(5)F_(2)(OH)_(4)]anionic group that i...A new deep-ultraviolet(DUV)birefringent crystal,LiB_(5)O_(5)F_(2)(OH)_(4)(LBOFH),was designed and synthesized by a high-temperature solution method.Its structure features a[B_(5)O_(5)F_(2)(OH)_(4)]anionic group that is constructed by four π-conjugated units,i.e.,two[BO_(3)]units and two[BO(OH)_(2)]units connected by the[BO_(2)F_(2)]unit,which forms a near-coplanar configuration.The group exhibits large anisotropic polarizability and highest unoccupied molecular orbital-lowest unoccupied molecular orbital(HUMO-LUMO)gap,thus providing a good balance between the large birefringence(0.124 at 546 nm)and band gap(7.99 eV)in LBOFH.This work suggests new possibilities for the design and fabrication of advanced DUV birefringent crystals using the novel anionic group and the expansion of their alternative system with new hydroxyfluorooxoborates.展开更多
Nonlinear optical(NLO)materials as a crucial part of the laser science have attracted increasing attention from researchers because of their wide applications in information storages,modern science and technologies,et...Nonlinear optical(NLO)materials as a crucial part of the laser science have attracted increasing attention from researchers because of their wide applications in information storages,modern science and technologies,et al.Based on the anionic group theory,theπ-conjugated 6-membered rings(6-MRs),B_(3)O_(6)-typed structures have key contributions to the superior optical properties ofβ-Ba_(2)B_(2)O_(4)(β-BBO).In recent years,the organic coplanarπ-conjugated B_(3)O_(6)-typed structures have caught researchers'attention due to similar configurations to the(B_(3)O_(6))groups,which are the potential sources for expending the(B_(3)O_(6))groups with outstanding optical properties.Up to know,researchers have obtained many ultraviolet(UV)NLO crystals with excellent properties withπ-conju-gated B_(3)O_(6)-typed groups.Herein,these B_(3)O_(6)-typed groups could be divided into different categories according to the atoms constituting the 6-MRs:(H_(x)C_(3)N_(3)O_(3))^(x-3)(x=0-3)(cyanurate ion),(H_(x)C_(4)N_(2)O_(3))^(x-4)(x=2,3)(barbi-turate ion),(C_(3)H_(7)N_(6))^(+)(melamine ion),(C_(5)H_(6)ON)^(+)(4-hydroxypyridine cation),and(C_(4)H_(6)N_(3))^(+)(2-amino-pyrimidinium cation).In this review,we introduced the research advances of NLO materials withπ-conjugated B_(3)O_(6)-typed groups,and summarized the crystal structures,synthetic methods,optical performances,as well as the relationships between structures and properties.This work provided a clear perspective for understanding the coplanarπ-conjugated B_(3)O_(6)-typed groups with their optical functional properties and promote the searches to develop potential NLO functional crystals.展开更多
基金National Natural Science Foundation of China (52372224 and 52072299)Major Project of Shaanxi Coal Joint Fund of Shaanxi Provincial Science and Technology Department (2019JLZ-07)。
文摘Na_(3)V_(2)(PO_(4))_(2)O_(2)F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity.Density functional theory (DFT) and finite element simulations show that incorporating SO_(4)^(2-)into VP decreases its band gap,lowers the migration energy barrier,and ensures a uniform Na+concentration gradient and stress distribution during charge and discharge cycles.Consequently,the average Na+diffusion coefficient of Na_(3)V_(2)(PO_(4))_(1.95)(SO_(4))_(0.05)O_(2)F(VPS-1) is roughly double that of VP,leading to enhanced rate capability (80 C,75.5 mAh g^(-1)) and cycling stability (111.0 mAh g^(-1)capacity after 1000 cycles at 10 C current density) for VPS-1.VPS-1 exhibits outstanding fast-charging capabilities,achieving an 80%state of charge in just 8.1 min.The assembled VPS-1//SbSn/NPC full cell demonstrated stable cycling over 200 cycles at a high 5 C current,maintaining an average coulombic efficiency of 95.35%.
基金supported by the National Natural Science Foundation of China(61875229 and 61922084)the Key Research Project of Frontier Science of CAS(QYZDB-SSW-JSC049)+1 种基金the West Light Foundation of CAS(2020-JCTD-002)the Instrument Developing Project of CAS(GJJSTD20200007)。
文摘A new deep-ultraviolet(DUV)birefringent crystal,LiB_(5)O_(5)F_(2)(OH)_(4)(LBOFH),was designed and synthesized by a high-temperature solution method.Its structure features a[B_(5)O_(5)F_(2)(OH)_(4)]anionic group that is constructed by four π-conjugated units,i.e.,two[BO_(3)]units and two[BO(OH)_(2)]units connected by the[BO_(2)F_(2)]unit,which forms a near-coplanar configuration.The group exhibits large anisotropic polarizability and highest unoccupied molecular orbital-lowest unoccupied molecular orbital(HUMO-LUMO)gap,thus providing a good balance between the large birefringence(0.124 at 546 nm)and band gap(7.99 eV)in LBOFH.This work suggests new possibilities for the design and fabrication of advanced DUV birefringent crystals using the novel anionic group and the expansion of their alternative system with new hydroxyfluorooxoborates.
基金supported by the National Natural Science Foundation of China(Grant Nos.22222510,21975255 and 21921001)the Foundation of Fujian Science&Technology Innovation Laboratory(2021ZR202)Youth Innovation Promotion Association CAS(2019303).
文摘Nonlinear optical(NLO)materials as a crucial part of the laser science have attracted increasing attention from researchers because of their wide applications in information storages,modern science and technologies,et al.Based on the anionic group theory,theπ-conjugated 6-membered rings(6-MRs),B_(3)O_(6)-typed structures have key contributions to the superior optical properties ofβ-Ba_(2)B_(2)O_(4)(β-BBO).In recent years,the organic coplanarπ-conjugated B_(3)O_(6)-typed structures have caught researchers'attention due to similar configurations to the(B_(3)O_(6))groups,which are the potential sources for expending the(B_(3)O_(6))groups with outstanding optical properties.Up to know,researchers have obtained many ultraviolet(UV)NLO crystals with excellent properties withπ-conju-gated B_(3)O_(6)-typed groups.Herein,these B_(3)O_(6)-typed groups could be divided into different categories according to the atoms constituting the 6-MRs:(H_(x)C_(3)N_(3)O_(3))^(x-3)(x=0-3)(cyanurate ion),(H_(x)C_(4)N_(2)O_(3))^(x-4)(x=2,3)(barbi-turate ion),(C_(3)H_(7)N_(6))^(+)(melamine ion),(C_(5)H_(6)ON)^(+)(4-hydroxypyridine cation),and(C_(4)H_(6)N_(3))^(+)(2-amino-pyrimidinium cation).In this review,we introduced the research advances of NLO materials withπ-conjugated B_(3)O_(6)-typed groups,and summarized the crystal structures,synthetic methods,optical performances,as well as the relationships between structures and properties.This work provided a clear perspective for understanding the coplanarπ-conjugated B_(3)O_(6)-typed groups with their optical functional properties and promote the searches to develop potential NLO functional crystals.
