@article{7672, abstract = {Large overpotentials upon discharge and charge of Li-O2 cells have motivated extensive research into heterogeneous solid electrocatalysts or non-carbon electrodes with the aim to improve rate capability, round-trip efficiency and cycle life. These features are equally governed by parasitic reactions, which are now recognized to be caused by the highly reactive singlet oxygen (1O2). However, the link between the presence of electrocatalysts and 1O2 formation in metal-O2 cells is unknown. Here, we show that, compared to pristine carbon black electrodes, a representative selection of electrocatalysts or non-carbon electrodes (noble metal, transition metal compounds) may both slightly reduce or severely increase the 1O2 formation. The individual reaction steps, where the surfaces impact the 1O2 yield are deciphered, showing that 1O2 yield from superoxide disproportionation as well as the decomposition of trace H2O2 are sensitive to catalysts. Transition metal compounds in general are prone to increase 1O2.}, author = {Samojlov, Aleksej and Schuster, David and Kahr, Jürgen and Freunberger, Stefan Alexander}, journal = {Electrochimica Acta}, number = {12}, publisher = {Elsevier}, title = {{Surface and catalyst driven singlet oxygen formation in Li-O2 cells}}, doi = {10.1016/j.electacta.2020.137175}, volume = {362}, year = {2020}, } @article{7847, abstract = {Water-in-salt electrolytes based on highly concentrated bis(trifluoromethyl)sulfonimide (TFSI) promise aqueous electrolytes with stabilities nearing 3 V. However, especially with an electrode approaching the cathodic (reductive) stability, cycling stability is insufficient. While stability critically relies on a solid electrolyte interphase (SEI), the mechanism behind the cathodic stability limit remains unclear. Here, we reveal two distinct reduction potentials for the chemical environments of 'free' and 'bound' water and that both contribute to SEI formation. Free-water is reduced ~1V above bound water in a hydrogen evolution reaction (HER) and responsible for SEI formation via reactive intermediates of the HER; concurrent LiTFSI precipitation/dissolution establishes a dynamic interface. The free-water population emerges, therefore, as the handle to extend the cathodic limit of aqueous electrolytes and the battery cycling stability. }, author = {Bouchal, Roza and Li, Zhujie and Bongu, Chandra and Le Vot, Steven and Berthelot, Romain and Rotenberg, Benjamin and Favier, Fréderic and Freunberger, Stefan Alexander and Salanne, Mathieu and Fontaine, Olivier}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, number = {37}, pages = {15913--1591}, publisher = {Wiley}, title = {{Competitive salt precipitation/dissolution during free‐water reduction in water‐in‐salt electrolyte}}, doi = {10.1002/anie.202005378}, volume = {59}, year = {2020}, } @article{7985, abstract = {The goal of limiting global warming to 1.5 °C requires a drastic reduction in CO2 emissions across many sectors of the world economy. Batteries are vital to this endeavor, whether used in electric vehicles, to store renewable electricity, or in aviation. Present lithium-ion technologies are preparing the public for this inevitable change, but their maximum theoretical specific capacity presents a limitation. Their high cost is another concern for commercial viability. Metal–air batteries have the highest theoretical energy density of all possible secondary battery technologies and could yield step changes in energy storage, if their practical difficulties could be overcome. The scope of this review is to provide an objective, comprehensive, and authoritative assessment of the intensive work invested in nonaqueous rechargeable metal–air batteries over the past few years, which identified the key problems and guides directions to solve them. We focus primarily on the challenges and outlook for Li–O2 cells but include Na–O2, K–O2, and Mg–O2 cells for comparison. Our review highlights the interdisciplinary nature of this field that involves a combination of materials chemistry, electrochemistry, computation, microscopy, spectroscopy, and surface science. The mechanisms of O2 reduction and evolution are considered in the light of recent findings, along with developments in positive and negative electrodes, electrolytes, electrocatalysis on surfaces and in solution, and the degradative effect of singlet oxygen, which is typically formed in Li–O2 cells.}, author = {Kwak, WJ and Sharon, D and Xia, C and Kim, H and Johnson, LR and Bruce, PG and Nazar, LF and Sun, YK and Frimer, AA and Noked, M and Freunberger, Stefan Alexander and Aurbach, D}, issn = {1520-6890}, journal = {Chemical Reviews}, number = {14}, pages = {6626--6683}, publisher = {American Chemical Society}, title = {{Lithium-oxygen batteries and related systems: Potential, status, and future}}, doi = {10.1021/acs.chemrev.9b00609}, volume = {120}, year = {2020}, } @article{8057, abstract = {Water-in-salt electrolytes based on highly concentrated bis(trifluoromethyl)sulfonimide (TFSI) promise aqueous electrolytes with stabilities approaching 3 V. However, especially with an electrode approaching the cathodic (reductive) stability, cycling stability is insufficient. While stability critically relies on a solid electrolyte interphase (SEI), the mechanism behind the cathodic stability limit remains unclear. Here, we reveal two distinct reduction potentials for the chemical environments of ‘free’ and ‘bound’ water and that both contribute to SEI formation. Free-water is reduced ~1V above bound water in a hydrogen evolution reaction (HER) and responsible for SEI formation via reactive intermediates of the HER; concurrent LiTFSI precipitation/dissolution establishes a dynamic interface. The free-water population emerges, therefore, as the handle to extend the cathodic limit of aqueous electrolytes and the battery cycling stability.}, author = {Bouchal, Roza and Li, Zhujie and Bongu, Chandra and Le Vot, Steven and Berthelot, Romain and Rotenberg, Benjamin and Favier, Frederic and Freunberger, Stefan Alexander and Salanne, Mathieu and Fontaine, Olivier}, issn = {1521-3757}, journal = {Angewandte Chemie}, number = {37}, pages = {16047--16051}, publisher = {Wiley}, title = {{Competitive salt precipitation/dissolution during free‐water reduction in water‐in‐salt electrolyte}}, doi = {10.1002/ange.202005378}, volume = {132}, year = {2020}, } @misc{8067, abstract = {With the lithium-ion technology approaching its intrinsic limit with graphite-based anodes, lithium metal is recently receiving renewed interest from the battery community as potential high capacity anode for next-generation rechargeable batteries. In this focus paper, we review the main advances in this field since the first attempts in the mid-1970s. Strategies for enabling reversible cycling and avoiding dendrite growth are thoroughly discussed, including specific applications in all-solid-state (polymeric and inorganic), Lithium-sulphur and Li-O2 (air) batteries. A particular attention is paid to review recent developments in regard of prototype manufacturing and current state-ofthe-art of these battery technologies with respect to the 2030 targets of the EU Integrated Strategic Energy Technology Plan (SET-Plan) Action 7.}, author = {Varzi, Alberto and Thanner, Katharina and Scipioni, Roberto and Di Lecce, Daniele and Hassoun, Jusef and Dörfler, Susanne and Altheus, Holger and Kaskel, Stefan and Prehal, Christian and Freunberger, Stefan Alexander}, issn = {2664-1690}, keywords = {Battery, Lithium metal, Lithium-sulphur, Lithium-air, All-solid-state}, pages = {63}, publisher = {IST Austria}, title = {{Current status and future perspectives of Lithium metal batteries}}, doi = {10.15479/AT:ISTA:8067}, year = {2020}, } @unpublished{8081, abstract = {Here, we employ micro- and nanosized cellulose particles, namely paper fines and cellulose nanocrystals, to induce hierarchical organization over a wide length scale. After processing them into carbonaceous materials, we demonstrate that these hierarchically organized materials outperform the best materials for supercapacitors operating with organic electrolytes reported in literature in terms of specific energy/power (Ragone plot) while showing hardly any capacity fade over 4,000 cycles. The highly porous materials feature a specific surface area as high as 2500 m2ˑg-1 and exhibit pore sizes in the range of 0.5 to 200 nm as proven by scanning electron microscopy and N2 physisorption. The carbonaceous materials have been further investigated by X-ray photoelectron spectroscopy and RAMAN spectroscopy. Since paper fines are an underutilized side stream in any paper production process, they are a cheap and highly available feedstock to prepare carbonaceous materials with outstanding performance in electrochemical applications. }, author = {Hobisch, Mathias A. and Mourad, Eléonore and Fischer, Wolfgang J. and Prehal, Christian and Eyley, Samuel and Childress, Anthony and Zankel, Armin and Mautner, Andreas and Breitenbach, Stefan and Rao, Apparao M. and Thielemans, Wim and Freunberger, Stefan Alexander and Eckhart, Rene and Bauer, Wolfgang and Spirk, Stefan }, title = {{High specific capacitance supercapacitors from hierarchically organized all-cellulose composites}}, year = {2020}, } @misc{9780, abstract = {PADREV : 4,4'-dimethoxy[1,1'-biphenyl]-2,2',5,5'-tetrol Space Group: C 2 (5), Cell: a 24.488(16)Å b 5.981(4)Å c 3.911(3)Å, α 90° β 91.47(3)° γ 90°}, author = {Schlemmer, Werner and Nothdurft, Philipp and Petzold, Alina and Riess, Gisbert and Frühwirt, Philipp and Schmallegger, Max and Gescheidt-Demner, Georg and Fischer, Roland and Freunberger, Stefan Alexander and Kern, Wolfgang and Spirk, Stefan}, publisher = {CCDC}, title = {{CCDC 1991959: Experimental Crystal Structure Determination}}, doi = {10.5517/ccdc.csd.cc24vsrk}, year = {2020}, }