Interfacial reactions in lithium-ion batteries often involve gaseous reaction products.Mechanistic investigation of material degradation processes requires a technique to identify and quantify these gases in battery c...Interfacial reactions in lithium-ion batteries often involve gaseous reaction products.Mechanistic investigation of material degradation processes requires a technique to identify and quantify these gases in battery cells.Online electrochemical mass spectrometry(OEMS)is an operando gas analysis method that continuously samples the headspace of a custom battery cell.Real-time gas analysis by quantitative OEMS was used to create mechanistic understanding of battery degradation reactions,some of which will be highlight in this article.展开更多
In this work,we demonstrate the power of a simple top-down electrochemical erosion approach to obtain Pt nanoparticle with controlled shapes and sizes(in the range from-2 to-10 nm).Carbon supported nanoparticles with ...In this work,we demonstrate the power of a simple top-down electrochemical erosion approach to obtain Pt nanoparticle with controlled shapes and sizes(in the range from-2 to-10 nm).Carbon supported nanoparticles with narrow size distributions have been synthesized by applying an alternating voltage to macroscopic bulk platinum structures,such as disks or wires.Without using any surfactants,the size and shape of the particles can be changed by adjusting simple parameters such as the applied potential,frequency and electrolyte composition.For instance,application of a sinusoidal AC voltage with lower frequencies results in cubic nanoparticles;whereas higher frequencies lead to predominantly spherical nanoparticles.On the other hand,the amplitude of the,sinusoidal signal was found to affect the particle size;the lower the amplitude of the applied AC signal,the smaller the resulting particle size.Pt/C catalysts prepared by this approach showed 0.76 A/mg mass activity towards the oxygen reduction reaction which is-2 times higher than the state-of-the-art commercial Pt/C catalyst(0.42 A/mg)from Tanaka.In addition to this,we discussed the mechanistic insights about the nanoparticle formation pathways.展开更多
基金BASF SE(Germany)for their fundingfunding from the German Federal Ministry of Education and Research(BMBF)within the projects ExZellTUMⅡ(grant number 03XP0081)and ExZellTUMⅢ(grant number 03XP0255)and of BMW AG。
文摘Interfacial reactions in lithium-ion batteries often involve gaseous reaction products.Mechanistic investigation of material degradation processes requires a technique to identify and quantify these gases in battery cells.Online electrochemical mass spectrometry(OEMS)is an operando gas analysis method that continuously samples the headspace of a custom battery cell.Real-time gas analysis by quantitative OEMS was used to create mechanistic understanding of battery degradation reactions,some of which will be highlight in this article.
基金support from Deutsche Forschungsgemeinschaft under Germany s excellence strategy-EXC 2089/1-390776260Germany’s excellence cluster“e-conversion”,DFG project BA 5795/4-1funding from the TUM IGSSE project 11.01 are gratefully acknowledged.We also acknowledge DESY(Hamburg,Germany),a member of the Helmholtz Association HGF,for the provision of experimental facilities.Parts of this research were carried out at PETRA III using beamline P02.1.We acknowledge CzechNanoLab Research Infrastructure supported by MEYS CR (LM2018110) and CEITEC Nano Research Infrastructure for TEM measurements.
文摘In this work,we demonstrate the power of a simple top-down electrochemical erosion approach to obtain Pt nanoparticle with controlled shapes and sizes(in the range from-2 to-10 nm).Carbon supported nanoparticles with narrow size distributions have been synthesized by applying an alternating voltage to macroscopic bulk platinum structures,such as disks or wires.Without using any surfactants,the size and shape of the particles can be changed by adjusting simple parameters such as the applied potential,frequency and electrolyte composition.For instance,application of a sinusoidal AC voltage with lower frequencies results in cubic nanoparticles;whereas higher frequencies lead to predominantly spherical nanoparticles.On the other hand,the amplitude of the,sinusoidal signal was found to affect the particle size;the lower the amplitude of the applied AC signal,the smaller the resulting particle size.Pt/C catalysts prepared by this approach showed 0.76 A/mg mass activity towards the oxygen reduction reaction which is-2 times higher than the state-of-the-art commercial Pt/C catalyst(0.42 A/mg)from Tanaka.In addition to this,we discussed the mechanistic insights about the nanoparticle formation pathways.
