Molecule-assisted modulation of the high-valence Co^(3+)in 3D honeycomb-like Co_(x)S_(y)networks for high-performance solid-state asymmetric supercapacitors  

分子辅助制备富含高价态Co^(3+)的三维蜂窝状钴硫化物网络结构用于高性能固态不对称超级电容器

作　　者：Haiyan Wang Ying Yang Qinghao Li Wen Lu Jiqiang Ning Yijun Zhong Ziyang Zhang Yong Hu 王海燕;杨瑛;李擎昊;陆雯;宁吉强;钟依均;张子旸;胡勇(Key Laboratory of the Ministry of Education for Advanced Catalysis Materials,Department of Chemistry,Zhejiang Normal University,Jinhua 321004,China;Vacuum Interconnected Nanotech Workstation,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China)

机构地区：[1]Key Laboratory of the Ministry of Education for Advanced Catalysis Materials,Department of Chemistry,Zhejiang Normal University,Jinhua 321004,China [2]Vacuum Interconnected Nanotech Workstation,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China

出　　处：《Science China Materials》2021年第4期840-851,共12页中国科学（材料科学（英文版）

基　　金：the National Natural Science Foundation of China(21671173);Zhejiang Provincial Ten Thousand Talent Program(2017R52043)。

摘　　要：Modulating the oxidation states of transition metal species has been regarded as a promising strategy to tune the redox activity and achieve more active sites in electrode materials.In this work,a unique three-dimensional(3D)honeycomb-like cobalt sulfide(Co_(x)S_(y))network organized by cross-linked nanosheets(Co_(x)S_(y)-T NSs)was prepared via a simple triethanolamine(TEOA)-assisted self-templating strategy.Interestingly,it has been found for the first time that the introduction of TEOA in the reaction effectively increases the ratio of high-valence Co^(3+)in the final product.Benefiting from the synergetic effect of the tailored high-valence Co^(3+)with the 3D network structure,the Co_(x)S_(y)-T NS electrode exhibits a maximum specific capacity of 351 mA h g^(-1)(2635 F g^(-1))at 5 A g^(-1)as well as excellent cycling stability.Furthermore,with the solid-state asymmetric supercapacitor(ASC)constructed based on the Co_(x)S_(y)-T NSs and activated carbon(AC)electrodes,a high energy density up to 81.62 W h kg^(-1)has been achieved at the power density of 0.81 kW kg^(-1)and 96.2%capacitance is preserved after 7000 cycles,indicating robust cycling stability.This result highlights the simple approach of simultaneously tailoring highvalence metal species and constructing 3D network structure toward high-performance electrode materials for energy storage and conversion.过渡金属氧化态调控工程是一种很有前景的改善电极材料的氧化还原活性、增加活性位点的策略.本文提出了一种简单的三乙醇胺辅助自模板法,制备了一种由交错钴硫化物纳米片(Co_(x)S_(y)-T NSs)组装而成的独特的三维蜂窝状网络结构.有趣的是,我们首次发现在该体系中,三乙醇胺可以有效地增加目标产物中的高价态Co^(3+)的比例.Co_(x)S_(y)-T NSs电极具有高含量的Co^(3+)和三维网络结构,使得其在5 A g^(-1)的电流密度下表现出351 mA h g^(-1)(2635 F g^(-1))的最大比容量和优异的循环稳定性.此外,由Co_(x)S_(y)-T NSs和活性炭(AC)电极组装的固态不对称超级电容器在0.81 kW kg^(-1)功率密度下展现出81.62 W h kg^(-1)的高能量密度和卓越的长周期循环稳定性,7000次循环后仍有96.2%的容量保持率.该结果证明同时调控高价态的金属物种并构筑三维网络结构是一种简单而有效的制备用于能源存储与转换的高活性电极材料的策略.

关 键 词：CoxSy triethanolamine-assisted self-templating strategy high-valence Co^(3+) 3D network solid-state asymmetric supercapacitors 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TM53[电气工程—电器]