Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, ...Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, so it is necessary to realize fast Mg2+ transport in the host in addition to other requirements as practical cathode materials for magnesium batteries. Positive electrode materials based on inorganic transition-metal oxides, sulfides, and borides are the only ones used up to now to insert magnesium ions. In this paper, the available results of research on materials suitable as possible, for secondary magnesium batteries, are reviewed.展开更多
In this letter, we report a quantitative analysis of how a Pt（II） precursor is reduced to atoms at different temperatures for the formation of Pt nanocrystals with different morphologies and sizes. Our results sugge...In this letter, we report a quantitative analysis of how a Pt（II） precursor is reduced to atoms at different temperatures for the formation of Pt nanocrystals with different morphologies and sizes. Our results suggest that in the early stage of a synthesis, the Pt（II） precursor is reduced to atoms exclusively in the solution phase, followed by homogeneous nucleation to generate nuclei and then seeds. At a relatively low reaction temperature such as 22℃, the growth of the seeds is dominated by autocatalytic surface reduction that involves the adsorption and then reduction of the Pt（II） precursor on the surface of the just-formed seeds. This particular growth pathway results in relatively large assemblies of Pt nanocrystals. When the reaction temperature is increased to 100 ℃, the dominant reduction pathway will be switched from surface to solution phase, producing much smaller asselnblies of Pt nanocrystals. Our results also demonstrate that a similar trend applies to the seed-rnediated growth of Pt nanocrystals in the presence of Pd nanocubes.展开更多
基金supported by the National Natural Science foundation of China(No.50081004,50271032)the Special Fund for Major State Basic Research of China(973 Project 2002 CB 211800)Nankai-Tianjin University Union Science Fund.
文摘Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, so it is necessary to realize fast Mg2+ transport in the host in addition to other requirements as practical cathode materials for magnesium batteries. Positive electrode materials based on inorganic transition-metal oxides, sulfides, and borides are the only ones used up to now to insert magnesium ions. In this paper, the available results of research on materials suitable as possible, for secondary magnesium batteries, are reviewed.
基金supported in part by a grant from National Science Foundation of the United States(DMR-1505441)startup funds from the Georgia Institute of Technology
文摘In this letter, we report a quantitative analysis of how a Pt（II） precursor is reduced to atoms at different temperatures for the formation of Pt nanocrystals with different morphologies and sizes. Our results suggest that in the early stage of a synthesis, the Pt（II） precursor is reduced to atoms exclusively in the solution phase, followed by homogeneous nucleation to generate nuclei and then seeds. At a relatively low reaction temperature such as 22℃, the growth of the seeds is dominated by autocatalytic surface reduction that involves the adsorption and then reduction of the Pt（II） precursor on the surface of the just-formed seeds. This particular growth pathway results in relatively large assemblies of Pt nanocrystals. When the reaction temperature is increased to 100 ℃, the dominant reduction pathway will be switched from surface to solution phase, producing much smaller asselnblies of Pt nanocrystals. Our results also demonstrate that a similar trend applies to the seed-rnediated growth of Pt nanocrystals in the presence of Pd nanocubes.
