A versatile spectroelectrochemical measurement method of surface-enhanced Raman scattering spectroscopy is developed,and its capability is assessed in an actual electrochemical system.The spectroelectrochemical cell c...A versatile spectroelectrochemical measurement method of surface-enhanced Raman scattering spectroscopy is developed,and its capability is assessed in an actual electrochemical system.The spectroelectrochemical cell consists of a plasmonic sensor with metal nanoparticles and a wire-type working electrode.The advantages of this method over conventional surface-enhanced Raman scattering methods are as follows:1)surface-enhanced Raman scattering for electrode materials that show little plasmon resonance;and 2)measurement without undesirable influences on the physical and chemical states of the electrode surface and transport phenomena of reaction species.During the measurement,the sensor contacts the working electrode wire at a single point,allowing the surface-enhanced Raman scattering signal to be obtained from the interfacial area of the working electrode surface without significantly disturbing the mass transfer of the reaction species.As plasmon-active metal nanoparticles are modified on the sensor surface in advance,destructive and complicated pretreatment processes on the working electrode are not required.The method is applied to the in situ analysis of electrolyte decomposition reactions in a Li metal battery to reveal the potential of each decomposition product of an organic solvent containing Li.The obtained surface-enhanced Raman scattering spectrum corresponding to the voltammogram reveals the pathway for obtaining decomposition products,such as Li_(2)CO_(3).In particular,Li_(2)O_(2)was clearly detected with our setup.It is also revealed from the setup that the Ni electrode surface,in contrast to the Cu,does not hold a stable Li-containing composite layer.Such in situ chemical information will contribute to the effective interfacial design of high-performance batteries.展开更多
In this study,ZnO formation during the dissolution-passivation process of Zn anodes is observed via in situ Raman and optical characterization.The Zn passivation during galvanostatic anodization merely follows the dis...In this study,ZnO formation during the dissolution-passivation process of Zn anodes is observed via in situ Raman and optical characterization.The Zn passivation during galvanostatic anodization merely follows the dissolution-precipitation model,whereas that of potentiodynamic polarization exhibits different behaviors in different potential ranges.Initially,the Zn electrode is gradually covered by a ZnO precipitation film and then undergoes solid-state oxidation at~255 mV.The starting point of solid-state oxidation is well indicated by the abrupt current drop and yellow coloration of the electrode surface.During the pseudo passivation,an intense current oscillation is observed.Further,blink-like color changes between yellow and dark blue are revealed for the first time,implying that the oscillation is caused by the dynamic adsorption and desorption of OH groups.The as-formed ZnOs then experience a dissolution-reformation evolution,during which the crystallinity of the primary ZnO film is improved but the solid-state-formed ZnO layer becomes rich in oxygen vacancies.Eventually,oxide densification is realized,contributing to the Zn passivation.This study provides new insights into the Zn dissolution-passivation behavior,which is critical for the future optimization of Zn batteries.展开更多
基金is partly based on the results obtained from the“Research and Development Initiative for Scientific Innovation of New Generation Batteries 2 and 3(RISING2 and RISING3)”projects commissioned by the New EnergyIndustrial Technology Development Organization(NEDO),Japan(Project codes:JPNP16001 and JPNP21006).
文摘A versatile spectroelectrochemical measurement method of surface-enhanced Raman scattering spectroscopy is developed,and its capability is assessed in an actual electrochemical system.The spectroelectrochemical cell consists of a plasmonic sensor with metal nanoparticles and a wire-type working electrode.The advantages of this method over conventional surface-enhanced Raman scattering methods are as follows:1)surface-enhanced Raman scattering for electrode materials that show little plasmon resonance;and 2)measurement without undesirable influences on the physical and chemical states of the electrode surface and transport phenomena of reaction species.During the measurement,the sensor contacts the working electrode wire at a single point,allowing the surface-enhanced Raman scattering signal to be obtained from the interfacial area of the working electrode surface without significantly disturbing the mass transfer of the reaction species.As plasmon-active metal nanoparticles are modified on the sensor surface in advance,destructive and complicated pretreatment processes on the working electrode are not required.The method is applied to the in situ analysis of electrolyte decomposition reactions in a Li metal battery to reveal the potential of each decomposition product of an organic solvent containing Li.The obtained surface-enhanced Raman scattering spectrum corresponding to the voltammogram reveals the pathway for obtaining decomposition products,such as Li_(2)CO_(3).In particular,Li_(2)O_(2)was clearly detected with our setup.It is also revealed from the setup that the Ni electrode surface,in contrast to the Cu,does not hold a stable Li-containing composite layer.Such in situ chemical information will contribute to the effective interfacial design of high-performance batteries.
基金supported by the Research and Development Initiative for Scientific Innovation of New Generation Batteries(RISING)Projects,RISING2[JPNP16001]and RISING3[JPNP21006],commissioned by of the New Energy and Industrial Technology Development Organization(NEDO),Japanthe State Scholarship Fund of the China Scholarship Council[No.201906230294]for their support
文摘In this study,ZnO formation during the dissolution-passivation process of Zn anodes is observed via in situ Raman and optical characterization.The Zn passivation during galvanostatic anodization merely follows the dissolution-precipitation model,whereas that of potentiodynamic polarization exhibits different behaviors in different potential ranges.Initially,the Zn electrode is gradually covered by a ZnO precipitation film and then undergoes solid-state oxidation at~255 mV.The starting point of solid-state oxidation is well indicated by the abrupt current drop and yellow coloration of the electrode surface.During the pseudo passivation,an intense current oscillation is observed.Further,blink-like color changes between yellow and dark blue are revealed for the first time,implying that the oscillation is caused by the dynamic adsorption and desorption of OH groups.The as-formed ZnOs then experience a dissolution-reformation evolution,during which the crystallinity of the primary ZnO film is improved but the solid-state-formed ZnO layer becomes rich in oxygen vacancies.Eventually,oxide densification is realized,contributing to the Zn passivation.This study provides new insights into the Zn dissolution-passivation behavior,which is critical for the future optimization of Zn batteries.
