Herein, we report the electrochemical Li intake capacity of carbonaceous one-dimensional graphene nanoribbons (GNRs) obtained by unzipping pristine multiwalled carbon nanotubes (MWCNTs). We have found that nanotubes with diameters of approximately 50 nm present a smaller reversible capacity than conventional mesocarbon microbead (MCMB) powder. Reduced GNRs improve the capacity only marginally over the MCMB reference but present a lower Coulombic efficiency as well as a higher capacity loss per cycle. Oxidized GNRs (ox-GNRs) outperform all of the other materials studied here in terms of energy density. They present a first charge capacity of approximately 1400 mA h g(-1) with a low Coulombic efficiency for the first cycle (approximately 53%). The reversible capacity of ox-GNRs is in the range of 800 mA h g(-1), with a capacity loss per cycle of approximately 3% for early cycles and a decreasing loss rate for subsequent cycles.

Herein, we describe the design and testing of two different home-built atomic layer deposition (ALD) systems for the growth of thin films with sub-monolayer control over film thickness. The first reactor is a horizontally aligned hot-walled reactor with a vacuum purging system. The second reactor is a vertically aligned cold-walled reactor with a quartz crystal microbalance (QCM) and a vacuum purging system. This latter reactor was also built to be capable of the addition of liquid- or solution-phase precursors, including the addition of a solution-based precursor containing nanoparticles. Each system cost less than $10,000, and they were used to deposit aluminum oxide thin films using trimethylaluminum and water/isopropyl alcohol as coreactants. Whereas the horizontal hot-walled system was able to deposit alumina thin films at a growth rate of 1.2–1.4 Å/cycle, the more sophisticated vertically aligned reactor deposited films at 0.95–1.1 Å/cycle, which is comparable to commercial systems costing $100,000 or more. Most importantly, both systems were fabricated entirely by M.S. and undergraduate students at Central Michigan University.

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