Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in dev...Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in developing electrode materials enabling reversible Na+insertion/desertion and fast reaction kinetics.Herein,a core-shell structure,FeS2 nanoparticles encapsulated in biphase TiO2 shell(FeS2@TiO2),is developed towards the improvement of sodium storage.The diphase TiO2 coating supplies abundant anatase/rutile interface and oxygen vacancies which will enhance the charge transfer,and avoid severe volume variation of FeS2 caused by the Na+insertion.The FeS2 core will deliver high theoretical capacity through its conversion reaction mechanism.Consequently,the FeS2@TiO2 nanorods display notable performance as anode for SIBs including long-term cycling performance(637.8 m A·h·g^-1 at 0.2 A·g^-1 after 300 cycles,374.9 m A·h·g^-1 at 5.0 A·g^-1 after 600 cycles)and outstanding rate capability(222.2 m A·h·g^-1 at 10 A·g^-1).Furthermore,the synthesized FeS2@TiO2 demonstrates significant pseudocapacitive behavior which accounts for 90.7%of the Na+storage,and efficiently boosts the rate capability.This work provides a new pathway to fabricate anode material with an optimized structure and crystal phase for SIBs.展开更多
Biphasic defective TiO2-x/reduced graphene oxide（RGO） nanocomposites were synthesized by simple hydrothermal reactions. Compared with TiO2-x and commercial P25, TiO2-x/RGO shows much better photocatalytic activity a...Biphasic defective TiO2-x/reduced graphene oxide（RGO） nanocomposites were synthesized by simple hydrothermal reactions. Compared with TiO2-x and commercial P25, TiO2-x/RGO shows much better photocatalytic activity and excellent stability in pollutants degradation, which could be ascribed to Ti^3＋ centers complexed with RGO and the synergetic effect between the two phases. The study reveals a new route for the synthesis of mixed-phase defective TiO2-x/carbon material nanocomposites for photocatalytic applications.展开更多
基金supported by the National Nature Science Foundation of China(No.51775366)。
文摘Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in developing electrode materials enabling reversible Na+insertion/desertion and fast reaction kinetics.Herein,a core-shell structure,FeS2 nanoparticles encapsulated in biphase TiO2 shell(FeS2@TiO2),is developed towards the improvement of sodium storage.The diphase TiO2 coating supplies abundant anatase/rutile interface and oxygen vacancies which will enhance the charge transfer,and avoid severe volume variation of FeS2 caused by the Na+insertion.The FeS2 core will deliver high theoretical capacity through its conversion reaction mechanism.Consequently,the FeS2@TiO2 nanorods display notable performance as anode for SIBs including long-term cycling performance(637.8 m A·h·g^-1 at 0.2 A·g^-1 after 300 cycles,374.9 m A·h·g^-1 at 5.0 A·g^-1 after 600 cycles)and outstanding rate capability(222.2 m A·h·g^-1 at 10 A·g^-1).Furthermore,the synthesized FeS2@TiO2 demonstrates significant pseudocapacitive behavior which accounts for 90.7%of the Na+storage,and efficiently boosts the rate capability.This work provides a new pathway to fabricate anode material with an optimized structure and crystal phase for SIBs.
基金Supported by the Doctoral Startup Foundation of Anhui University, China（No. 10113190077）, the Natural Science Founda- tion of Anhui Province, China（No. 1608085QB39） and the National Natural Science Foundation of China（No. 51402001）.
文摘Biphasic defective TiO2-x/reduced graphene oxide（RGO） nanocomposites were synthesized by simple hydrothermal reactions. Compared with TiO2-x and commercial P25, TiO2-x/RGO shows much better photocatalytic activity and excellent stability in pollutants degradation, which could be ascribed to Ti^3＋ centers complexed with RGO and the synergetic effect between the two phases. The study reveals a new route for the synthesis of mixed-phase defective TiO2-x/carbon material nanocomposites for photocatalytic applications.
