Dennis Tench

Bio: Dennis Tench is an academic researcher from Rockwell International. The author has contributed to research in topics: Plating & Ultimate tensile strength. The author has an hindex of 14, co-authored 33 publications receiving 948 citations. Previous affiliations of Dennis Tench include Rockwell Automation.

Electrodeposition of Conducting Transition Metal Oxide/Hydroxide Films from Aqueous Solution

Abstract: Donnees sur une methode generale de depot electrolytique de couches minces d'oxyde-hydroxyde de Cu, Ni, Co, Fe et Mn, a partir d'une solution aqueuse, sur une electrode a disque tournant de Pt, soit sous tension constant, soit sous tension variant cycliquement

Enhanced tensile strength for electrodeposited nickel-copper multilayer composites

Abstract: The tensile strength of electrodeposited layered composites of the nominal overall composition 90 pct Ni-10 pct Cu is shown to increase sharply to the 1300 MPa range as the thickness of the Cu layers is decreased below ~0.4 ώm. This tensile strength value is almost a factor of three greater than that measured for Ni itself, and more than a factor of two greater than the handbook value for Monel 400.

Protection of Semiconductor Photoanodes with Photoelectrochemically Generated Polypyrrole Films

Abstract: Results are presented which show that photoelectrochemically generated polypyrrole films protect semiconductor photoanodes (e.g., Cd chalcogenides,, and Si), from degradation while permitting electron exchange between the semiconductor and the electrolyte. The performance characteristics and stability of such film‐covered photoelectrodes are discussed.

Method for evaluating the quality of electroplating baths

Abstract: A working electrode is swept through a voltammetric cycle, including a metal plating range and a metal stripping range, for at least two baths of known plating quality and a bath whose quality is to be evaluated. The current utilized during the metal stripping range is correlated to the quality of the baths of known quality. The current utilized to strip the metal in the bath of unknown quality is compared to the correlation and its quality evaluated. In a preferred embodiment, an inert working electrode is swept by a function generator through the voltammetric cycle. A counter electrode immersed in the plating bath is coupled in series with the function generator and a coulometer to measure the charge during the metal stripping portion of the cycle.

A Bifunctional Nonprecious Metal Catalyst for Oxygen Reduction and Water Oxidation

Abstract: There is a growing interest in oxygen electrochemistry as conversions between O(2) and H(2)O play an important role in a variety of renewable energy technologies. The goal of this work is to develop active bifunctional catalyst materials for water oxidation and oxygen reduction. Drawing inspiration from a cubane-like CaMn(4)O(x), the biological catalyst found in the oxygen evolving center (OEC) in photosystem II, nanostructured manganese oxide surfaces were investigated for these reactions. Thin films of nanostructured manganese oxide were found to be active for both oxygen reduction and water oxidation, with similar overall oxygen electrode activity to the best known precious metal nanoparticle catalysts: platinum, ruthenium, and iridium. Physical and chemical characterization of the nanostructured Mn oxide bifunctional catalyst reveals an oxidation state of Mn(III), akin to one of the most commonly observed Mn oxidation states found in the OEC.

Three-dimensional bicontinuous ultrafast-charge and -discharge bulk battery electrodes

Abstract: Rapid charge and discharge rates have become an important feature of electrical energy storage devices, but cause dramatic reductions in the energy that can be stored or delivered by most rechargeable batteries (their energy capacity). Supercapacitors do not suffer from this problem, but are restricted to much lower stored energy per mass (energy density) than batteries. A storage technology that combines the rate performance of supercapacitors with the energy density of batteries would significantly advance portable and distributed power technology. Here, we demonstrate very large battery charge and discharge rates with minimal capacity loss by using cathodes made from a self-assembled three-dimensional bicontinuous nanoarchitecture consisting of an electrolytically active material sandwiched between rapid ion and electron transport pathways. Rates of up to 400C and 1,000C for lithium-ion and nickel-metal hydride chemistries, respectively, are achieved (where a 1C rate represents a one-hour complete charge or discharge), enabling fabrication of a lithium-ion battery that can be 90% charged in 2 minutes.