Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance,but their development is plagued by limited choices of cathode materials with satisfactory ...Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance,but their development is plagued by limited choices of cathode materials with satisfactory cycling performance.The polyoxometalates perform formidable redox stability and able to participate in multi-electron transfer,which was well-suited for energy storage.Herein,a bicomponent polyoxometalate-derivative KNiVO(K_(2)[Ni(H_(2)O)_(6)]_(2)[V_(10)O_(28)]·_(4)H_(2)O polyoxometalates after annealing)is firstly demonstrated as a cathode material for aqueous ZIBs.The layered KV_(3)O_(8)(KVO)In the bi-component material constitutes Zn^(2+) migration and storage channels(K^(+) were substantially replaced by Zn^(2+) in the activation phase),and the three-dimensional NiV_(3)O_(8)(NiVO)part acts as skeleton to stabilize the ion channels,which assist the cell to demonstrate a high-rate capacity and specific energy of229.4 mAh/g and satisfactory cyclability(capacity retention of 99.1%after 4500 cycles at a current density of 4 A/g).These results prove the feasibility of POM as cathode materials precursor and put forward a novel pattern of the Zn^(2+)storage mechanism in the activated-KNiVO clusters,which also provide a new route for selecting or designing high-performance cathode for aqueous ZIBs and other advanced battery systems.展开更多
A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac-...A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac- tivity and high selectivity of dimethyldichlorosilane （M2） in the stirred bed reactor. The effect of the proportion of CuC1 used was studied and 10%-30% CuC1 gave the best yield of M2. The use of CuC1 decreased the induction pe- riod of reaction, improved the selectivity in the induction stage, and gave a longer stable stage. These results sug- gest that bi-comoonent catalyst has advantazes in the direct synthesis reaction.展开更多
We obtain bi-component Coulomb crystals using laser-cooled ^40Ca^+ ions to sympathetically cool ^9Be^+ ions in a linear Paul trap. The shell structures of the bi-component Coulomb crystals are investigated. The secula...We obtain bi-component Coulomb crystals using laser-cooled ^40Ca^+ ions to sympathetically cool ^9Be^+ ions in a linear Paul trap. The shell structures of the bi-component Coulomb crystals are investigated. The secular motion frequencies of the two different ions are determined and compared with those in the single-component Coulomb crystals. In the radial direction, the resonant motion frequencies of the two ionic species shift toward each other due to the strong motion coupling in the ion trap. In the axial direction, the motion frequency of the laser-cooled ^40Ca^+is impervious to the sympathetically cooled ^9Be^+ ions because the spatially separation of the two different ionic species leads to the weak motion coupling in the axial direction.展开更多
基金supported by the Natural Science Foundation of Hunan Province(No.2020JJ4684)the Fundamental Research Funds for the Central Universities of Central South University(No.2021zzts0522)the Recruitment Program of Global Youth Experts。
文摘Rechargeable aqueous zinc-ion batteries are recently gaining incremental attention because of low cost and material abundance,but their development is plagued by limited choices of cathode materials with satisfactory cycling performance.The polyoxometalates perform formidable redox stability and able to participate in multi-electron transfer,which was well-suited for energy storage.Herein,a bicomponent polyoxometalate-derivative KNiVO(K_(2)[Ni(H_(2)O)_(6)]_(2)[V_(10)O_(28)]·_(4)H_(2)O polyoxometalates after annealing)is firstly demonstrated as a cathode material for aqueous ZIBs.The layered KV_(3)O_(8)(KVO)In the bi-component material constitutes Zn^(2+) migration and storage channels(K^(+) were substantially replaced by Zn^(2+) in the activation phase),and the three-dimensional NiV_(3)O_(8)(NiVO)part acts as skeleton to stabilize the ion channels,which assist the cell to demonstrate a high-rate capacity and specific energy of229.4 mAh/g and satisfactory cyclability(capacity retention of 99.1%after 4500 cycles at a current density of 4 A/g).These results prove the feasibility of POM as cathode materials precursor and put forward a novel pattern of the Zn^(2+)storage mechanism in the activated-KNiVO clusters,which also provide a new route for selecting or designing high-performance cathode for aqueous ZIBs and other advanced battery systems.
文摘A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac- tivity and high selectivity of dimethyldichlorosilane （M2） in the stirred bed reactor. The effect of the proportion of CuC1 used was studied and 10%-30% CuC1 gave the best yield of M2. The use of CuC1 decreased the induction pe- riod of reaction, improved the selectivity in the induction stage, and gave a longer stable stage. These results sug- gest that bi-comoonent catalyst has advantazes in the direct synthesis reaction.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91636216,11504410 and 11474317the Strategic Priority Research Program(B) of the Chinese Academy of Sciences under Grant No XDB21020200
文摘We obtain bi-component Coulomb crystals using laser-cooled ^40Ca^+ ions to sympathetically cool ^9Be^+ ions in a linear Paul trap. The shell structures of the bi-component Coulomb crystals are investigated. The secular motion frequencies of the two different ions are determined and compared with those in the single-component Coulomb crystals. In the radial direction, the resonant motion frequencies of the two ionic species shift toward each other due to the strong motion coupling in the ion trap. In the axial direction, the motion frequency of the laser-cooled ^40Ca^+is impervious to the sympathetically cooled ^9Be^+ ions because the spatially separation of the two different ionic species leads to the weak motion coupling in the axial direction.
