A series of bimetallic nickel cobalt sulfides with hierarchical micro/nano architectures were fabricated via a facile synthesis strategy of bimetallic micro/nano structure precursor construction-anion exchange via sol...A series of bimetallic nickel cobalt sulfides with hierarchical micro/nano architectures were fabricated via a facile synthesis strategy of bimetallic micro/nano structure precursor construction-anion exchange via solvothermal method. Among the nickel cobalt sulfides with different Ni/Co contents, the coral-like Ni1.01Co1.99S4 (Ni/Co, 1/2) delivers ultrafast and stable Na-ion storage performance (350 mAh·g−1 after 1,000 cycles at 1 A·g−1 and 355 mAh·g−1 at 5 A·g−1). The remarkable electrochemical properties can be attributed to the enhanced conductivity by co-existence of bimetallic components, the unique coral-like micro/nanostructure, which could prevent structural collapse and self-aggregation of nanoparticles, and the easily accessibility of electrolyte, and fast Na+ diffusion upon cycling. Detailed kinetics studies by a galvanostatic intermittent titration technique (GITT) reveal the dynamic change of Na+ diffusion upon cycling, and quantitative kinetic analysis indicates the high contribution of pseudocapacitive behavior during charge-discharge processes. Moreover, the ex-situ characterization analysis results further verify the Na-ion storage mechanism based on conversion reaction. This study is expected to provide a feasible design strategy for the bimetallic sulfides materials toward high performance sodium-ion batteries.展开更多
基金supported by the Leading Talents in Science and Technology Innovation under the National Ten Thousand Talents Plan,the National Natural Science Foundation of China(51833006 and 52003154)the Innovation Program of Shanghai Municipal Education Commission(201701070002E00061)+3 种基金the Science and Technology Commission of Shanghai Municipality(19441903000 and 19ZR1425400)Shanghai Jiao Tong University(SJTU)Trans-med Awards Research(WF540162603)Shanghai Pujiang Program(20PJ1407400)the Natural Science Foundation of Shanghai(20ZR1425500)。
基金This work was supported by the Shandong Provincial Natural Science Foundation (Nos. ZR2020QB123, ZR2020QB108, and ZR2019MEM030)the National Natural Science Foundation of China (Nos. 51972180, 22071135, and 51572134)+2 种基金Academy of Sciences large apparatus United Fund of China (No. U1832187)Key Research & Development Project of Shandong Province (No. 2019GGX102070)the Program for Scientific Research Innovation Team in Colleges and Universities of Jinan (No. 2018GXRC006).
文摘A series of bimetallic nickel cobalt sulfides with hierarchical micro/nano architectures were fabricated via a facile synthesis strategy of bimetallic micro/nano structure precursor construction-anion exchange via solvothermal method. Among the nickel cobalt sulfides with different Ni/Co contents, the coral-like Ni1.01Co1.99S4 (Ni/Co, 1/2) delivers ultrafast and stable Na-ion storage performance (350 mAh·g−1 after 1,000 cycles at 1 A·g−1 and 355 mAh·g−1 at 5 A·g−1). The remarkable electrochemical properties can be attributed to the enhanced conductivity by co-existence of bimetallic components, the unique coral-like micro/nanostructure, which could prevent structural collapse and self-aggregation of nanoparticles, and the easily accessibility of electrolyte, and fast Na+ diffusion upon cycling. Detailed kinetics studies by a galvanostatic intermittent titration technique (GITT) reveal the dynamic change of Na+ diffusion upon cycling, and quantitative kinetic analysis indicates the high contribution of pseudocapacitive behavior during charge-discharge processes. Moreover, the ex-situ characterization analysis results further verify the Na-ion storage mechanism based on conversion reaction. This study is expected to provide a feasible design strategy for the bimetallic sulfides materials toward high performance sodium-ion batteries.
