@article{SunOsenbergDongetal.2018, author = {Sun, Fu and Osenberg, Markus and Dong, Kang and Zhou, Dong and Hilger, Andre and Jafta, Charl J. and Risse, Sebastian and Lu, Yan and Markoetter, Henning and Manke, Ingo}, title = {Correlating Morphological Evolution of Li Electrodes with Degrading Electrochemical Performance of Li/LiCoO2 and Li/S Battery Systems}, series = {ACS energy letters / American Chemical Society}, volume = {3}, journal = {ACS energy letters / American Chemical Society}, number = {2}, publisher = {American Chemical Society}, address = {Washington}, issn = {2380-8195}, doi = {10.1021/acsenergylett.7b01254}, pages = {356 -- 365}, year = {2018}, abstract = {Efficient Li utilization is generally considered to be a prerequisite for developing next-generation energy storage systems (ESSs). However, uncontrolled growth of Li microstructures (LmSs) during electrochemical cycling has prevented its practical commercialization. Herein, we attempt to understand the correlation of morphological evolution of Li electrodes with degrading electrochemical performances of Li/LiCoO2 and Li/S systems by synchrotron X-ray phase contrast tomography technique. It was found that the continuous transformation of the initial dense Li bulk to a porous lithium interface (PL1) structure intimately correlates with the gradually degrading overall cell performance of these two systems. Additionally, the formation mechanism of the PLI and its correlation with previously reported inwardly growing LmS and the lithium-reacted region have been intensively discussed. The information that we gain herein is complementary to previous investigations and may provide general insights into understanding of degradation mechanisms of Li metal anodes and also provide highly needed guidelines for effective design of reliable next-generation Li metal-based ESSs.}, language = {en} } @article{SunDongOsenbergetal.2018, author = {Sun, Fu and Dong, Kang and Osenberg, Markus and Hilger, Andre and Risse, Sebastian and Lu, Yan and Kamm, Paul H. and Klaus, Manuela and Markoetter, Henning and Garcia-Moreno, Francisco and Arlt, Tobias and Manke, Ingo}, title = {Visualizing the morphological and compositional evolution of the interface of InLi-anode|thio-LISION electrolyte in an all-solid-state Li-S cell by in operando synchrotron X-ray tomography and energy dispersive diffraction}, series = {Journal of materials chemistry : A, Materials for energy and sustainability}, volume = {6}, journal = {Journal of materials chemistry : A, Materials for energy and sustainability}, number = {45}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {2050-7488}, doi = {10.1039/c8ta08821g}, pages = {22489 -- 22496}, year = {2018}, abstract = {Dynamic and direct visualization of interfacial evolution is helpful in gaining fundamental knowledge of all-solid-state-lithium battery working/degradation mechanisms and clarifying future research directions for constructing next-generation batteries. Herein, in situ and in operando synchrotron X-ray tomography and energy dispersive diffraction were simultaneously employed to record the morphological and compositional evolution of the interface of InLi-anode|sulfide-solid-electrolyte during battery cycling. Compelling morphological evidence of interfacial degradation during all-solid-state-lithium battery operation has been directly visualized by tomographic measurement. The accompanying energy dispersive diffraction results agree well with the observed morphological deterioration and the recorded electrochemical performance. It is concluded from the current investigation that a fundamental understanding of the phenomena occurring at the solid-solid electrode|electrolyte interface during all-solid-state-lithium battery cycling is critical for future progress in cell performance improvement and may determine its final commercial viability.}, language = {en} } @article{GuRisseLuetal.2019, author = {Gu, Sasa and Risse, Sebastian and Lu, Yan and Ballauff, Matthias}, title = {Mechanism of the oxidation of 3,3′,5,5′-tetramethylbenzidine catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes}, series = {ChemPhysChem}, volume = {21}, journal = {ChemPhysChem}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4235}, doi = {10.1002/cphc.201901087}, pages = {450 -- 458}, year = {2019}, abstract = {Experimental and kinetic modelling studies are presented to investigate the mechanism of 3,3 ',5,5 '-tetramethylbenzidine (TMB) oxidation by hydrogen peroxide (H2O2) catalyzed by peroxidase-like Pt nanoparticles immobilized in spherical polyelectrolyte brushes (SPB-Pt). Due to the high stability of SPB-Pt colloidal, this reaction can be monitored precisely in situ by UV/VIS spectroscopy. The time-dependent concentration of the blue-colored oxidation product of TMB expressed by different kinetic models was used to simulate the experimental data by a genetic fitting algorithm. After falsifying the models with abundant experimental data, it is found that both H2O2 and TMB adsorb on the surface of Pt nanoparticles to react, indicating that the reaction follows the Langmuir-Hinshelwood mechanism. A true rate constant k, characterizing the rate-determining step of the reaction and which is independent on the amount of catalysts used, is obtained for the first time. Furthermore, it is found that the product adsorbes strongly on the surface of nanoparticles, thus inhibiting the reaction. The entire analysis provides a new perspective to study the catalytic mechanism and evaluate the catalytic activity of the peroxidase-like nanoparticles.}, language = {en} }