Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in seconda...Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.展开更多
Value is the scale that appraises whether the comparison between a certain thing and its realization which we need to consume is rational. The paper appraises the investment value and incomes of human capital by apply...Value is the scale that appraises whether the comparison between a certain thing and its realization which we need to consume is rational. The paper appraises the investment value and incomes of human capital by applying value engineering method. It elaborates the investment structure and contents of human capital first, and then analyzes and summarizes various functions of enterprise＇s human capital. It educes the production function and the optimum equilibrium solution of human capital on this basis. Finally, it appraises the investment value of human capital by applying VE method. Thus we will apply a new method in the human capital field.展开更多
Applying the strategic performance method of the balanced score card and the new thinking, the text structures the balanced score card theoretical model Party and government, further investigates and sets up of perfor...Applying the strategic performance method of the balanced score card and the new thinking, the text structures the balanced score card theoretical model Party and government, further investigates and sets up of performance evaluation to the Chinese leaders of the the applied function model and appraisal model of the balanced score card theoretical model of performance evaluation to the Chinese leaders of the Party and government. The foundation and implementation of these kinds of models can improve its competence and reign power; will promote the whole performance development of the Chinese Party and government organs, it will create the enormous economic benefits and social benefits.展开更多
We report for the first time a Na-ion battery anode material composed of P-doped CoSe_(2)nanoparticles(P-CoSe_(2))with the size of 5–20 nm that are uniformly embed in a 3 D porous honeycomb-like carbon network.High r...We report for the first time a Na-ion battery anode material composed of P-doped CoSe_(2)nanoparticles(P-CoSe_(2))with the size of 5–20 nm that are uniformly embed in a 3 D porous honeycomb-like carbon network.High rate capability and cycling stability are achieved simultaneously.The honeycomb-like carbon network is rationally designed to support high electrical conductivity,rapid Na-ion diffusion as well as the accommodation of the volume expansion from the active P-CoSe_(2)nanoparticles.In particular,heteroatom P-doping within CoSe_(2)introduces stronger P-Co bonds and additional P-Se bonds that significantly improve the structure stability of P-CoSe_(2)for highly stable sodiation/desodiation over long-term cycling.P-doping also improves the electrical conductivity of the CoSe_(2)nanoparticles,leading to highly elevated electrochemical kinetics to deliver high specific capacities at high current densities.Benefiting from the unique nanostructure and atomic-level P-doping,the P-CoSe_(2)(2:1)/C anode delivers an excellent cycle stability with a specific capacity of 206.9 mA h g^(-1)achieved at 2000 mA g^(-1)after 1000 cycles.In addition,this material can be synthesized using a facile pyrolysis and selenization/phosphorization approach.This study provides new opportunities of heteroatom doping as an effective method to improve the cycling stability of Na-ion anode materials.展开更多
基金financially supported by the Shenzhen Science and Technology Program(JCYJ20220530141012028),ChinaThe National Natural Science Foundation of China(22005178),China+2 种基金The Key Research and Development Program of Shandong Province(2021ZLGX01),ChianThe fellowship of China Postdoctoral Science Foundation(2022M722333),Chianthe Jiangsu Funding Program for Excellent Postdoctoral Talent,Chian。
文摘Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.
文摘Value is the scale that appraises whether the comparison between a certain thing and its realization which we need to consume is rational. The paper appraises the investment value and incomes of human capital by applying value engineering method. It elaborates the investment structure and contents of human capital first, and then analyzes and summarizes various functions of enterprise＇s human capital. It educes the production function and the optimum equilibrium solution of human capital on this basis. Finally, it appraises the investment value of human capital by applying VE method. Thus we will apply a new method in the human capital field.
文摘Applying the strategic performance method of the balanced score card and the new thinking, the text structures the balanced score card theoretical model Party and government, further investigates and sets up of performance evaluation to the Chinese leaders of the the applied function model and appraisal model of the balanced score card theoretical model of performance evaluation to the Chinese leaders of the Party and government. The foundation and implementation of these kinds of models can improve its competence and reign power; will promote the whole performance development of the Chinese Party and government organs, it will create the enormous economic benefits and social benefits.
基金the Natural Science Foundation of Shandong Province(No.ZR2019QEM001)the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515111089)the National Natural Science Foundation of China(Grant No.22005178)。
文摘We report for the first time a Na-ion battery anode material composed of P-doped CoSe_(2)nanoparticles(P-CoSe_(2))with the size of 5–20 nm that are uniformly embed in a 3 D porous honeycomb-like carbon network.High rate capability and cycling stability are achieved simultaneously.The honeycomb-like carbon network is rationally designed to support high electrical conductivity,rapid Na-ion diffusion as well as the accommodation of the volume expansion from the active P-CoSe_(2)nanoparticles.In particular,heteroatom P-doping within CoSe_(2)introduces stronger P-Co bonds and additional P-Se bonds that significantly improve the structure stability of P-CoSe_(2)for highly stable sodiation/desodiation over long-term cycling.P-doping also improves the electrical conductivity of the CoSe_(2)nanoparticles,leading to highly elevated electrochemical kinetics to deliver high specific capacities at high current densities.Benefiting from the unique nanostructure and atomic-level P-doping,the P-CoSe_(2)(2:1)/C anode delivers an excellent cycle stability with a specific capacity of 206.9 mA h g^(-1)achieved at 2000 mA g^(-1)after 1000 cycles.In addition,this material can be synthesized using a facile pyrolysis and selenization/phosphorization approach.This study provides new opportunities of heteroatom doping as an effective method to improve the cycling stability of Na-ion anode materials.
