Further development of high voltage lithium‐ion batteries requires electrolyte formulations stable against oxidation or measures to generate a protective cathode/electrolyte interface (CEI) film. In the frame of this work, the actually counterintuitive concept of using metal ions as electrolyte additives to stabilize the CEI has proven to be successful. The addition of 1 wt% magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) as electrolyte additive to a conventional LiPF6/organic carbonate electrolyte suppresses the oxidative decomposition of the bulk electrolyte as displayed in improved capacity retention, increased Coulombic efficiencies, and reduced self‐discharge of LiNi1/3Mn1/3Co1/3O2 (NMC111)/Li half cells charged to the elevated upper cutoff potential of 4.6 V versus Li/Li+ at 20 °C. Moreover, the addition of Mg(TFSI)2 shows no adverse effect on the cycling performance of graphite anodes, as observed by good long‐term cycling results of NMC111/graphite full cells. Ex situ analysis via X‐ray photoelectron spectroscopy, scanning electron microscopy, time‐of‐flight secondary ion mass spectrometry, and electron energy loss spectroscopy of the harvested NMC111 electrodes after cycling indicate that the addition of Mg2+ ions leads to the formation of a CEI layer as a result of an increased hydrolysis reaction of the PF6 – anion.

The size-dependent breeding of sodium chlorate crystals can be determined by carrying out experiments with seed crystals of optical antipodes of different sizes that undergo absolutely identical experimental conditions. Small portions of right-and left-handed seed crystals of different sizes were used. The number density distributions of the two opposite forms led to the total numbers of D-and L-crystals. The nucleation from different seed sizes under identical experimental conditions was found to be proportional to L4 in agreement with Clontz et al. [l] and Bennett et al. 121. A computer program for the modelling of batch crystallization was used to calculate the development of the nucleation process. The data for the supersaturation course and for the development of the population of the right-and left-handed crystals are in good agreement with the experimental results. Only few generations (one or two) of secondary nucleation are being built during the process because of the strong influence of the size of crystals on the nucleation rate. The formation of two generations of secondary nuclei could be observed during threehour batch crystallization runs.

The structure and chemical composition of boundary layers built under tribological stress impact the friction and wear of solid-state surfaces in a major way. Time-of-flight secondary ion mass spectrometry is ideally suited for the analysis of these boundary layers, including the adsorptive layer formed from oil additive components, and to advance the understanding of the interaction of all materials involved.Tribologically formed phosphate glass layers on friction body surfaces of standard wet multi-disc clutches, which had been exposed to defined loads in an environment of different model fluids of polyalphaolefin base oil blended with different single additives or well-defined mixtures of two additives, were investigated using time-of-flight secondary ion mass spectrometry. The obtained data give an insight on how additive-based reaction layers on friction surfaces may affect the friction curve of a wet clutch.

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5. 396-400 0 WILEY-VCH Verlag GmbH, D-69469 Weinheim. 1998 0009-286X/980404-0396 117.50+.50/0 -U n t e rs u c h u n g en z u r Se ku n d a r ke i mbildung von Natriumchlorat mit Hilfe der asymmetrischen Kristallisation*