Today, energy conversion devices typically rely on composite electrodes made of several materials interacting with one another. Understanding their individual and combined impacts on performance is essential in the pursuit of optimized systems. Unfortunately, this investigation is often disregarded in favor of quick publishable results. Here, designs of experiments are shown as capable of meeting both ends. Less than 100 different electrode formulations are defined with two active materials (LiFePO 4 and Li 4 Ti 5 O 12 ), two carbonaceous additives (carbon black and carbon nanofibers), and three binders (polyvinylidene fluoride, polyethylene-co-ethyl acrylate-co-maleic anhydride (Lotader 5500), and a hydrogenated nitrile butadiene rubber). Correlations with strong descriptive statistics are found between formulation and different limitations, indicating that maximum active material content should always be favored with a small fraction of both conductive additives and minimal binder content. With the help of designs of experiments, Lotader 5500-bound electrodes are optimized beyond typical formulations found in the literature.

Enantioselective cyclopropanation of α-carbonyl sulfoxonium ylides (SY) has so far been limited to addition/ring closure reactions on electron-poor olefins. Herein, we report the iridium-catalyzed intramolecular cyclopropanation of SY in the presence of a chiral diene in up to 96% yield and 98% enantioselectivity. Moreover, density functional theory calculations suggest that the re face of the olefin preferably attacks an iridium carbene intermediate in an asynchronous concerted step that is independent of the geometry of the olefin.

Controlling the behaviour of terminal alkynes in metal-catalysed intermolecular tandem reactions is a formidable challenge despite the potential advantage offered by these strategies in modern synthesis. Herein, we describe that a nickel catalyst enables a tandem consisting in the rapid dimerization of terminal alkynes into 1,3-enynes and the cycloaddition of these intermediates with an azetidinone, an oxetanone and benzocyclobutenones. Significantly, the slow or sequential additions of reagents and catalysts is not required to orchestrate their reactivity. These results are in stark contrast with previous cycloadditions of terminal alkynes with those strained four-membered ring substrates, which previously led to oligomerization or cyclotrimerization, except in the case of tert-butylacetylene.

Studies pinpointed the limitation of power-related performance for Li-ion batteries to the microstructure of each electrode.1, 2 This random arrangement of the active material (AM) and carbon filling particles bound by a polymer is typically characterized through physical values such as tortuosity, porosity and Mac Mullin Number.3 There is nonetheless no consensus on what the best formulation is for a given set of electrode components. The relationship between microstructure and performance is investigated by planning and analyzing a Design of Experiments based on a Complex Mixture Design. Thirty different formulations were characterized where Li4Ti5O12 was the AM, and carbon black and carbon nanofibers were conductive fillers. As for the binder, two were studied: polyvinylidene fluoride and a fluorine-free thermoplastic elastomer.4 All other factors, e.g. rheology or experimenter bias, were closely monitored and finely controlled to remain identical for all samples. Electrochemical performance were studied at low, medium and high charging speeds to account for different limitations of full capacity retention. Statistical analysis showed clear correlations between the formulation and the electrodes’ capacity with very high descriptive statistics, e.g. R2. Lastly, strong correlations were found between capacity and microstructure, strengthening further the trust in the empirical equations. These robust models helped choosing optimal fluorine-free formulations that surpassed even the highest performing previous electrodes. 1. Vasileiadis, A.; Klerk, N. J. J. d.; Smith, R. B.; Ganapathy, S.; Harks, P. P. R. M. L.; Bazant, M. Z.; Wagemaker, M., Toward Optimal Performance and In‐Depth Understanding of Spinel Li4Ti5O12 Electrodes through Phase Field Modeling. Advanced Functional Materials 2018, 0 (0), 1705992. 2. Ngandjong, A. C.; Rucci, A.; Maiza, M.; Shukla, G.; Vazquez-Arenas, J.; Franco, A. A., Multiscale Simulation Platform Linking Lithium Ion Battery Electrode Fabrication Process with Performance at the Cell Level. The Journal of Physical Chemistry Letters 2017, 8 (23), 5966-5972. 3. Landesfeind, J.; Hattendorff, J.; Ehrl, A.; Wall, W. A.; Gasteiger, H. A., Tortuosity Determination of Battery Electrodes and Separators by Impedance Spectroscopy. Journal of The Electrochemical Society 2016, 163 (7), A1373-A1387. 4. Rynne, O.; Lepage, D.; Aymé-Perrot, D.; Rochefort, D.; Dollé, M., Application of a Commercially-Available Fluorine-Free Thermoplastic Elastomer as a Binder for High-Power Li-Ion Battery Electrodes. Journal of The Electrochemical Society 2019, 166 (6), A1140-A1146. With this presentation, we want to show the versatility and power of Designs of Experiments to the community, whether for electrode formulation or new material synthesis, as the input parameters can be easily interchangeable. Figure 1