To anchor the polysulfide and enhance the conversion kinetics of polysulfide to disulfide/sulfide is critical for improving the performance of lithium-sulfur battery.For this purpose,the graphene-supported tin(Ⅳ) pho...To anchor the polysulfide and enhance the conversion kinetics of polysulfide to disulfide/sulfide is critical for improving the performance of lithium-sulfur battery.For this purpose,the graphene-supported tin(Ⅳ) phosphate(Sn(HPO_4)_2·H_2 O,SnP) composites(SnP-G) are employed as the novel sulfur hosts in this work.When compared to the graphene-sulfur and carbon-sulfur composites,the SnP-G-sulfur composites exhibit much better cycling performance at 1.0 C over 800 cycles.Meanwhile,the pouch cell fabricated with the SnP-G-sulfur cathodes also exhibits excellent performance with an initial capacity of1266.6 mAh g^(-1)(S) and capacity retention of 76.9% after 100 cycles at 0.1 C.The adsorption tests,density functional theory(DFT) calculations in combination with physical cha racterizations and electrochemical measurements provide insights into the mechanism of capture-accelerated conversion mechanism of polysulfide at the surface of SnP.DFT calculations indicate that the Li-O bond formed between Li atom(from Li_2 S_n,n=1,2,4,6,8) and O atom(from PO_3-OH in SnP) is the main reason for the strong interactions between Li_2 S_n and SnP.As a result,SnP can effectively restrain the shuttle effect and improving the cycling performance of Li-S cell.In addition,by employing the climbing-image nudged elastic band(ciNEB) methods,the energy barrier for lithium sulfide decomposition(charging reaction) on SnP is proved to decrease significantly compared to that on graphene.It can be concluded that SnP is an effective sulfur hosts acting as dual-functional accelerators for the conversion reactions of polysulfude to sulfide(discharging reaction) as well as polysulfide to sulfur(charging reaction).展开更多
Chelate tetra(acetylacetonato) tin(Ⅳ) was prepared and used as catalyst for polytrimethylene terephthalate synthesis.It exhibited higher catalytic activity than tetrabutyl titanate,butyltinhydroxide oxide and dibutyl...Chelate tetra(acetylacetonato) tin(Ⅳ) was prepared and used as catalyst for polytrimethylene terephthalate synthesis.It exhibited higher catalytic activity than tetrabutyl titanate,butyltinhydroxide oxide and dibutyltin oxide.Decrease in reaction time, content of terminal carboxyl group,color intensity and increase in intrinsic viscosity were observed.The unique molecular structure can be considered as factor remarkably improving the catalytic activity of tetra(acetylacetonato) tin(Ⅳ).展开更多
Four new five-coordinated anionic tin(Ⅳ) complexes with a form of [R_ n NH_ 4- n ][PhSn( μ 2-SCH_2COO)_2] were synthesized via the reaction of mercaptoacetic acid with phenyltin trichloride in the presence of dif...Four new five-coordinated anionic tin(Ⅳ) complexes with a form of [R_ n NH_ 4- n ][PhSn( μ 2-SCH_2COO)_2] were synthesized via the reaction of mercaptoacetic acid with phenyltin trichloride in the presence of different organic bases and characterized by means of IR, 1H NMR and MS spectroscopies. The crystal structure of [( i -Pr)_2NH_2] [PhSn( μ 2-SCH_2COO)_2] was determined by X-ray diffraction. In the crystal structure,the tin atom is five-coordinated and exists in trigonal bipyramid geometry with cell parameters a =1.1766(11) nm, b =1.3144(14) nm, c =1.3336(15) nm,β =90° and Z =4.展开更多
Axially substituted tin phthalocyanines, namely dichloride-tetra-（α-pentyloxy） tin （Ⅳ） phthalocyanine 2, dihydroxy-tetra-（α-pentyloxy） tin （Ⅳ） phthalocyanine 3 and its dimmer di-μ-oxo-tetra-（α-pentyloxy...Axially substituted tin phthalocyanines, namely dichloride-tetra-（α-pentyloxy） tin （Ⅳ） phthalocyanine 2, dihydroxy-tetra-（α-pentyloxy） tin （Ⅳ） phthalocyanine 3 and its dimmer di-μ-oxo-tetra-（α-pentyloxy） tin（Ⅳ） phthalocyanine 4 were synthesized. The catalytic effect of H2O-free CaCl2 in quinoline was used for condensation of dihydroxy tin phthalocyanine 3 to the cofacially array dimmer 4. Their structures were characterized by UV-vis, IR, elemental analysis, MS, as well as ^1HNMR spectroscopy.展开更多
Three tin ? complexes with N,N- dialkyl dithiocarbamates Ph3SnS2CN(CH3)C6 H5 (1),Ph3SnS2CN(C4H8NH) (2) and Sn(Cl)2(S2CNEt2)2 (3) have been synthesized. Th e crystal structures have been determined by X- ray sin- <I...Three tin ? complexes with N,N- dialkyl dithiocarbamates Ph3SnS2CN(CH3)C6 H5 (1),Ph3SnS2CN(C4H8NH) (2) and Sn(Cl)2(S2CNEt2)2 (3) have been synthesized. Th e crystal structures have been determined by X- ray sin- <IMG SRC="IMAGE/0915 0031.JPG" HEIGHT=11 WIDTH=12>gle crystal diffraction. A crystal of the complex 1 is triclinic with space group , a=0.9485(3)nm, b=1.0491(3)nm, c=1.3631(4)nm, α =70.996(4)° , β =72.294(4)° , γ =79.609(4)° , Z=2, V=1.2168(6)nm3, <IMG SR C="IMAGE/09150032.JPG" HEIGHT=11 WIDTH=12>Dc=1.453g· cm- 3, μ =1.234mm- 1, R =0.0442, wR=0.0858. A crystal of the complex 2 is monoclinic with space group P2 (1)/c, a=1.2214(2)nm, b=1.1651(2)nm, c=1.5769(3)nm,β =99.039(2)° , Z=2, V=2.21 62(7)nm3, Dc=1.532g· cm- 3, μ =1.352mm- 1, R=0.0267, wR=0.0591. A crystal of the complex 3 is triclinic with space group , a=0.7179(2)nm, b=0.9256(3)nm, c=1 .5327(5)nm,α =93.857(4)° ,β =98.992(4)° , γ =109.481(4)° , Z=2, V=0.9405(5 )nm3, Dc=1.717g· cm- 3, μ =2.076mm- 1, R=0.0263, wR=0.0662. In the complexes 1 and 2 the tin atoms rendered five- coordination in a distorted tigonal bipyr amidal structure and in the complex 3 the tin atom rendered six- coordination i n a distorted octahedron structure. CCDC: 1, 179918; 2, 180024; 3, 180004.展开更多
Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines...Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines. All of the compounds synthesized were characterized by elemental analysis, IR, 1H NMR. The crystal structures of [C 5H 5NH][Ph 2Sn(μ 2-SCH 2COO)Cl](6) and [PhMeNH 2]· [Ph 2Sn(μ 2-SCH 2COO)Cl](8) were determined by X-ray diffraction. In the crystal structure, there were trigonal bipyramid geometries with five-coordinated tin atom and hydrogen-bonding interaction between anionic and cationic ions. Crystals of compound 6 were monoclinic, space group P2 1/n, a= 1.034 7(4) nm, b=1.396 8(5) nm, c=1.405 6(5) nm, β=95.366(6)°, Z=4; Crystals of compound 8 were monoclinic, space group P2 1/c, a=0.922 9(3) nm, b=1.334 5(5) nm, c= 1.838 5(7) nm, β=93.673(7)°, Z=4.展开更多
基金supported by the funding from the Strategy Priority Research Program of Chinese Academy of Science (Grant No. XDA17020404)the DICP&QIBEBT (DICP&QIBEBT UN201702)+2 种基金the R&D Projects in Key Areas of Guangdong Province (2019B090908001)Science and Technology Innovation Foundation of Dalian (2018J11CY020)the Defense Industrial Technology Development Program (JCKY2018130C107)。
文摘To anchor the polysulfide and enhance the conversion kinetics of polysulfide to disulfide/sulfide is critical for improving the performance of lithium-sulfur battery.For this purpose,the graphene-supported tin(Ⅳ) phosphate(Sn(HPO_4)_2·H_2 O,SnP) composites(SnP-G) are employed as the novel sulfur hosts in this work.When compared to the graphene-sulfur and carbon-sulfur composites,the SnP-G-sulfur composites exhibit much better cycling performance at 1.0 C over 800 cycles.Meanwhile,the pouch cell fabricated with the SnP-G-sulfur cathodes also exhibits excellent performance with an initial capacity of1266.6 mAh g^(-1)(S) and capacity retention of 76.9% after 100 cycles at 0.1 C.The adsorption tests,density functional theory(DFT) calculations in combination with physical cha racterizations and electrochemical measurements provide insights into the mechanism of capture-accelerated conversion mechanism of polysulfide at the surface of SnP.DFT calculations indicate that the Li-O bond formed between Li atom(from Li_2 S_n,n=1,2,4,6,8) and O atom(from PO_3-OH in SnP) is the main reason for the strong interactions between Li_2 S_n and SnP.As a result,SnP can effectively restrain the shuttle effect and improving the cycling performance of Li-S cell.In addition,by employing the climbing-image nudged elastic band(ciNEB) methods,the energy barrier for lithium sulfide decomposition(charging reaction) on SnP is proved to decrease significantly compared to that on graphene.It can be concluded that SnP is an effective sulfur hosts acting as dual-functional accelerators for the conversion reactions of polysulfude to sulfide(discharging reaction) as well as polysulfide to sulfur(charging reaction).
基金the National High Technology Research and Development Program of China(No. 2003AA321010)the Innovation Research Fund of Graduate University,Chinese Academy of Sciences(2006)
文摘Chelate tetra(acetylacetonato) tin(Ⅳ) was prepared and used as catalyst for polytrimethylene terephthalate synthesis.It exhibited higher catalytic activity than tetrabutyl titanate,butyltinhydroxide oxide and dibutyltin oxide.Decrease in reaction time, content of terminal carboxyl group,color intensity and increase in intrinsic viscosity were observed.The unique molecular structure can be considered as factor remarkably improving the catalytic activity of tetra(acetylacetonato) tin(Ⅳ).
文摘Four new five-coordinated anionic tin(Ⅳ) complexes with a form of [R_ n NH_ 4- n ][PhSn( μ 2-SCH_2COO)_2] were synthesized via the reaction of mercaptoacetic acid with phenyltin trichloride in the presence of different organic bases and characterized by means of IR, 1H NMR and MS spectroscopies. The crystal structure of [( i -Pr)_2NH_2] [PhSn( μ 2-SCH_2COO)_2] was determined by X-ray diffraction. In the crystal structure,the tin atom is five-coordinated and exists in trigonal bipyramid geometry with cell parameters a =1.1766(11) nm, b =1.3144(14) nm, c =1.3336(15) nm,β =90° and Z =4.
文摘Axially substituted tin phthalocyanines, namely dichloride-tetra-（α-pentyloxy） tin （Ⅳ） phthalocyanine 2, dihydroxy-tetra-（α-pentyloxy） tin （Ⅳ） phthalocyanine 3 and its dimmer di-μ-oxo-tetra-（α-pentyloxy） tin（Ⅳ） phthalocyanine 4 were synthesized. The catalytic effect of H2O-free CaCl2 in quinoline was used for condensation of dihydroxy tin phthalocyanine 3 to the cofacially array dimmer 4. Their structures were characterized by UV-vis, IR, elemental analysis, MS, as well as ^1HNMR spectroscopy.
文摘Three tin ? complexes with N,N- dialkyl dithiocarbamates Ph3SnS2CN(CH3)C6 H5 (1),Ph3SnS2CN(C4H8NH) (2) and Sn(Cl)2(S2CNEt2)2 (3) have been synthesized. Th e crystal structures have been determined by X- ray sin- <IMG SRC="IMAGE/0915 0031.JPG" HEIGHT=11 WIDTH=12>gle crystal diffraction. A crystal of the complex 1 is triclinic with space group , a=0.9485(3)nm, b=1.0491(3)nm, c=1.3631(4)nm, α =70.996(4)° , β =72.294(4)° , γ =79.609(4)° , Z=2, V=1.2168(6)nm3, <IMG SR C="IMAGE/09150032.JPG" HEIGHT=11 WIDTH=12>Dc=1.453g· cm- 3, μ =1.234mm- 1, R =0.0442, wR=0.0858. A crystal of the complex 2 is monoclinic with space group P2 (1)/c, a=1.2214(2)nm, b=1.1651(2)nm, c=1.5769(3)nm,β =99.039(2)° , Z=2, V=2.21 62(7)nm3, Dc=1.532g· cm- 3, μ =1.352mm- 1, R=0.0267, wR=0.0591. A crystal of the complex 3 is triclinic with space group , a=0.7179(2)nm, b=0.9256(3)nm, c=1 .5327(5)nm,α =93.857(4)° ,β =98.992(4)° , γ =109.481(4)° , Z=2, V=0.9405(5 )nm3, Dc=1.717g· cm- 3, μ =2.076mm- 1, R=0.0263, wR=0.0662. In the complexes 1 and 2 the tin atoms rendered five- coordination in a distorted tigonal bipyr amidal structure and in the complex 3 the tin atom rendered six- coordination i n a distorted octahedron structure. CCDC: 1, 179918; 2, 180024; 3, 180004.
文摘Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines. All of the compounds synthesized were characterized by elemental analysis, IR, 1H NMR. The crystal structures of [C 5H 5NH][Ph 2Sn(μ 2-SCH 2COO)Cl](6) and [PhMeNH 2]· [Ph 2Sn(μ 2-SCH 2COO)Cl](8) were determined by X-ray diffraction. In the crystal structure, there were trigonal bipyramid geometries with five-coordinated tin atom and hydrogen-bonding interaction between anionic and cationic ions. Crystals of compound 6 were monoclinic, space group P2 1/n, a= 1.034 7(4) nm, b=1.396 8(5) nm, c=1.405 6(5) nm, β=95.366(6)°, Z=4; Crystals of compound 8 were monoclinic, space group P2 1/c, a=0.922 9(3) nm, b=1.334 5(5) nm, c= 1.838 5(7) nm, β=93.673(7)°, Z=4.
