Sodium-carbon dioxide(Na-CO_(2))batteries are regarded as promising energy storage technologies because of their impressive theoretical energy density and CO_(2)reutilization,but their practical applications are restr...Sodium-carbon dioxide(Na-CO_(2))batteries are regarded as promising energy storage technologies because of their impressive theoretical energy density and CO_(2)reutilization,but their practical applications are restricted by uncontrollable sodium dendrite growth and poor electrochemical kinetics of CO_(2)cathode.Constructing suitable multifunctional electrodes for dendritefree anodes and kinetics-enhanced CO_(2)cathodes is considered one of the most important ways to advance the practical application of Na-CO_(2)batteries.Herein,RuO2 nanoparticles encapsulated in carbon paper(RuCP)are rationally designed and employed as both Na anode host and CO_(2)cathode in Na-CO_(2)batteries.The outstanding sodiophilicity and high catalytic activity of RuCP electrodes can simultaneously contribute to homogenous Na+distribution and dendrite-free sodium structure at the anode,as well as strengthen discharge and charge kinetics at the cathode.The morphological evolution confirmed the uniform deposition of Na on RuCP anode with dense and flat interfaces,delivering enhanced Coulombic efficiency of 99.5%and cycling stability near 1500 cycles.Meanwhile,Na-CO_(2)batteries with RuCP cathode demonstrated excellent cycling stability(>350 cycles).Significantly,implementation of a dendrite-free RuCP@Na anode and catalytic-site-rich RuCP cathode allowed for the construction of a symmetric Na-CO_(2)battery with long-duration cyclability,offering inspiration for extensive practical uses of Na-CO_(2)batteries.展开更多
Unexpected intercalation-dominated process is observed duri ng K^+insertion in WS2 in a voltage range of 0.01-3.0 V.This is different fromthe previously reported two-dimensional(2D)transition metal dichalcogenides tha...Unexpected intercalation-dominated process is observed duri ng K^+insertion in WS2 in a voltage range of 0.01-3.0 V.This is different fromthe previously reported two-dimensional(2D)transition metal dichalcogenides that undergo a conversion reaction in a low voltage rangewhen used as anodes in potassium-ion batteries.Charge/discharge processes in the K and Na cells are studied in parallel to demonstrate thedifferention storage mechanisms.The Na^+storage proceeds through intercalation and conversion reactions while the K^+storage is governedby an intercalation reaction.Owing to the reversible K^+intercalation in the van der Waals gaps,the WS2 anode exhibits a low decay rate of 0.07%per cycle,delivering a capacity of 103 mAh·g^-1 after 100 cycles at 100 mA·g^-1.It maintains 57%capacity at 800 mA·g^-1 and shows stablecyclability up to 400 cycles at 500 mA·g^-1.Kinetics study proves the facilitation of K^+transport is derived from the intercalation-dominatedmecha nism.Furthermore,the mechanismis verified by the density functional theory(DFT)calculations,showing that the progressive expansion of the interlayer space can account for the observed results.展开更多
基金support from the German Research Foundation(DFG:LE 2249/15-1)the Sino-German Center for Research Promotion(GZ1579)support from the China Scholarship Council(No.202106370041)
文摘Sodium-carbon dioxide(Na-CO_(2))batteries are regarded as promising energy storage technologies because of their impressive theoretical energy density and CO_(2)reutilization,but their practical applications are restricted by uncontrollable sodium dendrite growth and poor electrochemical kinetics of CO_(2)cathode.Constructing suitable multifunctional electrodes for dendritefree anodes and kinetics-enhanced CO_(2)cathodes is considered one of the most important ways to advance the practical application of Na-CO_(2)batteries.Herein,RuO2 nanoparticles encapsulated in carbon paper(RuCP)are rationally designed and employed as both Na anode host and CO_(2)cathode in Na-CO_(2)batteries.The outstanding sodiophilicity and high catalytic activity of RuCP electrodes can simultaneously contribute to homogenous Na+distribution and dendrite-free sodium structure at the anode,as well as strengthen discharge and charge kinetics at the cathode.The morphological evolution confirmed the uniform deposition of Na on RuCP anode with dense and flat interfaces,delivering enhanced Coulombic efficiency of 99.5%and cycling stability near 1500 cycles.Meanwhile,Na-CO_(2)batteries with RuCP cathode demonstrated excellent cycling stability(>350 cycles).Significantly,implementation of a dendrite-free RuCP@Na anode and catalytic-site-rich RuCP cathode allowed for the construction of a symmetric Na-CO_(2)battery with long-duration cyclability,offering inspiration for extensive practical uses of Na-CO_(2)batteries.
文摘Unexpected intercalation-dominated process is observed duri ng K^+insertion in WS2 in a voltage range of 0.01-3.0 V.This is different fromthe previously reported two-dimensional(2D)transition metal dichalcogenides that undergo a conversion reaction in a low voltage rangewhen used as anodes in potassium-ion batteries.Charge/discharge processes in the K and Na cells are studied in parallel to demonstrate thedifferention storage mechanisms.The Na^+storage proceeds through intercalation and conversion reactions while the K^+storage is governedby an intercalation reaction.Owing to the reversible K^+intercalation in the van der Waals gaps,the WS2 anode exhibits a low decay rate of 0.07%per cycle,delivering a capacity of 103 mAh·g^-1 after 100 cycles at 100 mA·g^-1.It maintains 57%capacity at 800 mA·g^-1 and shows stablecyclability up to 400 cycles at 500 mA·g^-1.Kinetics study proves the facilitation of K^+transport is derived from the intercalation-dominatedmecha nism.Furthermore,the mechanismis verified by the density functional theory(DFT)calculations,showing that the progressive expansion of the interlayer space can account for the observed results.
