Pretreatment electrolytic cathodic

As an electrolyte, Nafion 112 (Du Pont, Inc) membrane was pretreated using H2O2, H2SO4 and deionized water before ion beam bombardment. The prepared membranes with a size of 8 X 8 cm were mounted on a bombardment frame with a window size of 5 x 5 cm, equal to the active area of the test fuel cells, and dried up at 80 C for 2 hr. Then, the mounted membrane was brought in a vacuum chamber equipped with a hollow cathode ion beam source as described in the previous study [1]. Ion dose was measured using a Faraday cup. Ion density... 

Ti was chosen as the cathode material for all of the following experiments except when otherwise indicated. This material is much cheaper than Pt and, when properly pretreated, has an electrolytic property good enough for our purpose. 

Formation of the SEI layer plays an important role on the cycling stability of silicon-based anodes. Kulova and Skundin [109] reported a method used to preform the SEI layer on an electrode surface (prior to initial cathodic polarization) by direct contact of silicon and lithium metal in the electrolyte. The electrolyte was 1-M LiC104 in a mixture of propylene carbonate (PC) and dimethoxyethane. This method effectively reduced the irreversible capacity of the amorphous silicon electrode. Pretreatment of nanometer-sized silicon in ethanol also can form functionalized surfaces on the silicon particles that improve adhesion of silicon-based electrodes. A stable capacity of 2,500 mAh/g after 25 cycles has been reported for ethanol-treated silicon electrodes [110]. 

It was concluded first by Knorr and coworkers [1] that diffusion of molecular hydrogen is the rate-determining step of hydrogen evolution on smooth platinum and palladium electrodes pretreated anodically. The same conclusion holds for the anodic processes given by Eq. 1 and 2. The interpretation based on steady-state measurements [1] is valid at cathodic current densities — i < 1 mA/cm in strong acid electrolytes (0d.H+ 1)- The correctness of this interpretation has been substantiated by a number of independent techniques which allow the concentration Ch2 of H2 molecules adjacent to the surface to be determined ... 

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