The transition probabilities, the dissociation widths, and the associated Fano parameters for rovibronic lines with J"=0,...,3 of the absorption bands of the B"B 1Sigmau+ state out of the X 1Sigmag+ v"=0 ground state were measured over the complete vibrational progression, showing clearly that only the inner-well state with B" 4psigma character can absorb vuv light and predissociate efficiently. The absolute values of these transition probablities, predissociation widths, and Fano parameters were found to agree well with ab initio calculations if one takes into account that the calculations neglect nonadiabatic couplings.

The pressure dependence study of the decay of the Lyman-α fluorescence induced by the dissociation of the doubly excited states enables us to determine the 2s-to-2p dissociation channel cross section ratio, and the cross sections of each dissociation channel. Evidence of new dissociations was obtained: the Q 1 1 (2) state dissociates into H(2s) + H(1s) and the Q 3 states into H(2s) + H(nλ).

Silicon-based anodes for lithium-ion batteries exhibit severe volumetric changes of the active material particles during (de-)lithiation, resulting in continuously occurring side reactions at the silicon/electrolyte interface over extended charge/discharge cycling. The thus formed and accumulating electrolyte decomposition products lead to a growth of the solid-electrolyte-interphase (SEI) on the silicon particles. This results not only in an ongoing loss of electrolyte but also in a significant swelling and impedance increase of silicon-based anodes which significantly compromises their cycle-life. In the present study, neutron depth profiling (NDP) is used post mortem as a non-destructive, highly lithium-sensitive technique to (i) quantify the amount of lithium-containing electrolyte decomposition products in silicon-graphite (SiG) electrodes (35 wt% silicon, areal capacity ∼1.7 mAh cm −2), (ii) monitor their distribution across the SiG electrode thickness, and (iii) determine the active material utilization across the electrode over 140 cycles. Hence, SiG negative electrodes are aged and characterized by means of galvanostatic cycling in SiG//LiFePO 4 pseudofull cells, using a capacitively oversized positive electrode and an electrolyte mixture consisting of 1 M LiPF 6 in EC:EMC with 5 wt% FEC. High-resolution cross-sectional SEM images and post-mortem characterization of the SiG electrodes with respect to changes in electrode mass thickness complement the analysis.

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