The octahedral tunnel-like three-dimensional(3D)structure of V_(2)O_(3)enables fast metal ion(de)intercalation and high capacity in aqueous zinc-ion batteries(ZIBs),but suffers from phase transition-induced structural...The octahedral tunnel-like three-dimensional(3D)structure of V_(2)O_(3)enables fast metal ion(de)intercalation and high capacity in aqueous zinc-ion batteries(ZIBs),but suffers from phase transition-induced structural degradation and capacity fading.Herein,we demonstrate that the undesirable phase transition of V_(2)O_(3)can be effectively suppressed through a new La^(3+)doping strategy and its implementation as a robust ZIBs cathode.The introduced La^(3+)ions not only can increase cell volume and expand ion channels of V_(2)O_(3)but also offer plentiful Zn^(2+)storage sites and promote the transport of Zn^(2+)ions and electrons.In particular,the doping of La^(3+)maintains the octahedral tunnel structure of V_(2)O_(3)and prevents its phase transition during(dis)charge,which improves the cycle stability of the V_(2)O_(3)cathode in ZIBs.By virtue of the above favorable factors,La-doped V_(2)O_(3)electrode presents an impressive discharge capacity of632.1 m Ah g^(-1)at 0.1 A g^(-1)after 100 cycles with a capacity retention up to 93.1%.Even at 10 A g^(-1),its discharge capacity remains at 342.7 mAh g^(-1)after 1000 cycles with a capacity attenuation of solely0.0069%per cycle.This work establishes rare-earth cation doping as a universal paradigm to reconcile structural stability and multi-electron redox activity in high-capacity battery electrodes.展开更多
The current vanadium extraction process from sodium roasted vanadium slag poses risks such as ammonia pollution.This study proposes a novel calcium-based vanadium extraction and hydrolysis precipitation process,achiev...The current vanadium extraction process from sodium roasted vanadium slag poses risks such as ammonia pollution.This study proposes a novel calcium-based vanadium extraction and hydrolysis precipitation process,achieving clean and efficient vanadium recovery.The introduction of Ca O facilitates the targeted reconstruction and conversion of vanadium and calcium in the solution,forming acidsoluble calcium vanadate intermediates.Under optimal conditions,n(Ca)/n(V)ratio of 1.75,extraction temperature of 90℃,and extraction time of 90 min,the vanadium extraction ratio reached 99.83%.This process also separates vanadium from sodium and silicon,enabling one-step purification of the vanadium solution.Subsequent sulfuric acid leaching,conducted at p H of 4.0,90℃,and 60 min,achieved a vanadium leaching ratio of 99.72%,further separating vanadium from calcium and other impurities.Finally,the purified vanadium solution underwent hydrolysis precipitation at p H of 2.1 and 95℃for60 min,achieving a precipitation ratio of 98.69%.The calcined product yielded V_(2)O_(5) with a purity of 98.60%.Compared to the conventional sodium roasting—water leaching along with ammonium salt precipitation process,this innovative method eliminates ammonia-nitrogen wastewater emissions.This study provides a foundation for the development of new vanadium extraction technologies from vanadium slag.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51962027,and 52262039)the Fundamental Research Funds for Inner Mongolia University of Science&Technology(No.2024QNJS071,2023QNJS052 and 2024QNJS064)+2 种基金the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT24002)the Central Guidance Fund for Local Scientific and Technological Development(2024ZY0012)the Ordos Higher Education Institutions Scientific Research Innovation Project(KYLJ25Z004)。
文摘The octahedral tunnel-like three-dimensional(3D)structure of V_(2)O_(3)enables fast metal ion(de)intercalation and high capacity in aqueous zinc-ion batteries(ZIBs),but suffers from phase transition-induced structural degradation and capacity fading.Herein,we demonstrate that the undesirable phase transition of V_(2)O_(3)can be effectively suppressed through a new La^(3+)doping strategy and its implementation as a robust ZIBs cathode.The introduced La^(3+)ions not only can increase cell volume and expand ion channels of V_(2)O_(3)but also offer plentiful Zn^(2+)storage sites and promote the transport of Zn^(2+)ions and electrons.In particular,the doping of La^(3+)maintains the octahedral tunnel structure of V_(2)O_(3)and prevents its phase transition during(dis)charge,which improves the cycle stability of the V_(2)O_(3)cathode in ZIBs.By virtue of the above favorable factors,La-doped V_(2)O_(3)electrode presents an impressive discharge capacity of632.1 m Ah g^(-1)at 0.1 A g^(-1)after 100 cycles with a capacity retention up to 93.1%.Even at 10 A g^(-1),its discharge capacity remains at 342.7 mAh g^(-1)after 1000 cycles with a capacity attenuation of solely0.0069%per cycle.This work establishes rare-earth cation doping as a universal paradigm to reconcile structural stability and multi-electron redox activity in high-capacity battery electrodes.
基金financially supported by the National Natural Science Foundation of China(52204309,52174277 and 52374300)Fundamental Funds for the Central Universities(N2425026)Liaoning Province Science and Technology Plan Joint Fund(2023-MSBA-052)。
文摘The current vanadium extraction process from sodium roasted vanadium slag poses risks such as ammonia pollution.This study proposes a novel calcium-based vanadium extraction and hydrolysis precipitation process,achieving clean and efficient vanadium recovery.The introduction of Ca O facilitates the targeted reconstruction and conversion of vanadium and calcium in the solution,forming acidsoluble calcium vanadate intermediates.Under optimal conditions,n(Ca)/n(V)ratio of 1.75,extraction temperature of 90℃,and extraction time of 90 min,the vanadium extraction ratio reached 99.83%.This process also separates vanadium from sodium and silicon,enabling one-step purification of the vanadium solution.Subsequent sulfuric acid leaching,conducted at p H of 4.0,90℃,and 60 min,achieved a vanadium leaching ratio of 99.72%,further separating vanadium from calcium and other impurities.Finally,the purified vanadium solution underwent hydrolysis precipitation at p H of 2.1 and 95℃for60 min,achieving a precipitation ratio of 98.69%.The calcined product yielded V_(2)O_(5) with a purity of 98.60%.Compared to the conventional sodium roasting—water leaching along with ammonium salt precipitation process,this innovative method eliminates ammonia-nitrogen wastewater emissions.This study provides a foundation for the development of new vanadium extraction technologies from vanadium slag.
