采用溶剂热法制备前驱体,后经350°C热处理,首次合成了空心结构的NiMn_2O_4微球以及不同含量氧化石墨烯包覆的Ni/Mn_3O_4/NiMn_2O_4@RGO复合材料.电化学性能测试表明,复合负极材料中,含25wt%还原氧化石墨烯的材料储钠性能最佳,其在5...采用溶剂热法制备前驱体,后经350°C热处理,首次合成了空心结构的NiMn_2O_4微球以及不同含量氧化石墨烯包覆的Ni/Mn_3O_4/NiMn_2O_4@RGO复合材料.电化学性能测试表明,复合负极材料中,含25wt%还原氧化石墨烯的材料储钠性能最佳,其在50 m A·g^(-1)电流密度下,100次循环后放电比容量保持在187.8 m Ah·g^(-1),且800 m A·g^(-1)电流密度下的可逆容量高达149.9 m Ah·g^(-1),明显优于NiMn_2O_4及其他石墨烯基复合材料.研究指出,复合材料性能的提升得益于空心微球和还原的氧化石墨烯构成的特殊结构,一方面缩短了电子/离子传输距离,缓解了体积效应,另一方面高导电网络有效增强了活性物质利用率.展开更多
将层状的LiNi1/3Co1/3Mn1/3O2锂离子电池正极材料与尖晶石型的LiMn2O4按质量比为2∶98混合烧结,采用X射线衍射（XRD）、循环伏安法（CV）、交流阻抗（EIS）以及充放电测试研究LiMn2O4对LiNi1/3Co1/3Mn1/3O2电化学性能的影响。研究表明混...将层状的LiNi1/3Co1/3Mn1/3O2锂离子电池正极材料与尖晶石型的LiMn2O4按质量比为2∶98混合烧结,采用X射线衍射（XRD）、循环伏安法（CV）、交流阻抗（EIS）以及充放电测试研究LiMn2O4对LiNi1/3Co1/3Mn1/3O2电化学性能的影响。研究表明混合LiMn2O4有利于提高LiNi1/3Co1/3Mn1/3O2正极材料的首次库仑效率、循环性能和倍率性能,在3.0~4.3 V以1 C循环,首次放电比容量和库仑效率分别为150.3 m Ah/g和85.5%,循环50次后容量保持率为88.9%;在5 C下充放电仍保持136.2 m Ah/g。循环伏安与交流阻抗测试表明混合2%（质量分数）LiMn2O4可以提升材料的可逆性和放电容量,降低电荷转移电阻。展开更多
A new compound, \[Ni(en)\-3\]\-2\[Ni(en)\-2(H\-2O)\-2\]\[As\-6V\-\{15\}O\-\{42\}\]·4H\-2O, was first prepared by hydrothermal synthesis and characterized by elemental analysis, IR, TGA\|DSC, ESR and single crysta...A new compound, \[Ni(en)\-3\]\-2\[Ni(en)\-2(H\-2O)\-2\]\[As\-6V\-\{15\}O\-\{42\}\]·4H\-2O, was first prepared by hydrothermal synthesis and characterized by elemental analysis, IR, TGA\|DSC, ESR and single crystal X\|ray diffraction. Crystal data: monoclinic, space group \%C\-c, a\%=1\^523 6(3) nm, \%b\%=2\^051 8(4) nm, \%c\%=2\^395 9(5) nm, \%β=97\^41(3)°, V\%=7\^427(3) nm\+3, \%Z=4, R=0\^057 0, wR\-2=0\^135 7\%. The polyanion consists of six AsO\-3 pyramids and fifteen VO\-5 pyramids. Counterions are complex ions with octahedral structure, which consist of NH\-2CH\-2CH\-2NH\-2 and Ni\+\{2+\}.展开更多
A new two dimensional 8 ring network nickle phosphate Ni 3(PO 4) 2·8H 2O was synthesized hydrothermally and its structure was determined by means of single crystal X ray diffraction. The Ni 3(PO 4) 2·8H 2O c...A new two dimensional 8 ring network nickle phosphate Ni 3(PO 4) 2·8H 2O was synthesized hydrothermally and its structure was determined by means of single crystal X ray diffraction. The Ni 3(PO 4) 2·8H 2O crystal crystallizes in the monoclinic system, space group C2/m , with M=128.13, a =0\^994 7(2) nm, b =1.321 7(3) nm; c =0.463 6(1) nm; β=104.80(3)°, V =0.589 3(2) nm 3, Z=2, R=0.027 2 and wR =0.057 5. The network structure consists of vertex sharing which results in the formation of undulating 4 ring chains and 8 ring sheets.展开更多
基金supported by the National Natural Science Foundation of China (51572194)the national Key Research and Development Program of China (No. 2018YFB0105900)the Tianjin Major Program of New Materials Science and Technology (No. 16ZXCLGX00070)
文摘采用溶剂热法制备前驱体,后经350°C热处理,首次合成了空心结构的NiMn_2O_4微球以及不同含量氧化石墨烯包覆的Ni/Mn_3O_4/NiMn_2O_4@RGO复合材料.电化学性能测试表明,复合负极材料中,含25wt%还原氧化石墨烯的材料储钠性能最佳,其在50 m A·g^(-1)电流密度下,100次循环后放电比容量保持在187.8 m Ah·g^(-1),且800 m A·g^(-1)电流密度下的可逆容量高达149.9 m Ah·g^(-1),明显优于NiMn_2O_4及其他石墨烯基复合材料.研究指出,复合材料性能的提升得益于空心微球和还原的氧化石墨烯构成的特殊结构,一方面缩短了电子/离子传输距离,缓解了体积效应,另一方面高导电网络有效增强了活性物质利用率.
文摘将层状的LiNi1/3Co1/3Mn1/3O2锂离子电池正极材料与尖晶石型的LiMn2O4按质量比为2∶98混合烧结,采用X射线衍射（XRD）、循环伏安法（CV）、交流阻抗（EIS）以及充放电测试研究LiMn2O4对LiNi1/3Co1/3Mn1/3O2电化学性能的影响。研究表明混合LiMn2O4有利于提高LiNi1/3Co1/3Mn1/3O2正极材料的首次库仑效率、循环性能和倍率性能,在3.0~4.3 V以1 C循环,首次放电比容量和库仑效率分别为150.3 m Ah/g和85.5%,循环50次后容量保持率为88.9%;在5 C下充放电仍保持136.2 m Ah/g。循环伏安与交流阻抗测试表明混合2%（质量分数）LiMn2O4可以提升材料的可逆性和放电容量,降低电荷转移电阻。
文摘A new compound, \[Ni(en)\-3\]\-2\[Ni(en)\-2(H\-2O)\-2\]\[As\-6V\-\{15\}O\-\{42\}\]·4H\-2O, was first prepared by hydrothermal synthesis and characterized by elemental analysis, IR, TGA\|DSC, ESR and single crystal X\|ray diffraction. Crystal data: monoclinic, space group \%C\-c, a\%=1\^523 6(3) nm, \%b\%=2\^051 8(4) nm, \%c\%=2\^395 9(5) nm, \%β=97\^41(3)°, V\%=7\^427(3) nm\+3, \%Z=4, R=0\^057 0, wR\-2=0\^135 7\%. The polyanion consists of six AsO\-3 pyramids and fifteen VO\-5 pyramids. Counterions are complex ions with octahedral structure, which consist of NH\-2CH\-2CH\-2NH\-2 and Ni\+\{2+\}.
文摘A new two dimensional 8 ring network nickle phosphate Ni 3(PO 4) 2·8H 2O was synthesized hydrothermally and its structure was determined by means of single crystal X ray diffraction. The Ni 3(PO 4) 2·8H 2O crystal crystallizes in the monoclinic system, space group C2/m , with M=128.13, a =0\^994 7(2) nm, b =1.321 7(3) nm; c =0.463 6(1) nm; β=104.80(3)°, V =0.589 3(2) nm 3, Z=2, R=0.027 2 and wR =0.057 5. The network structure consists of vertex sharing which results in the formation of undulating 4 ring chains and 8 ring sheets.
