Ni-Cds: the memory lingers on.

R S Skinner

doi:10.3109/17453059209051377

Home/Archive/PubMed

PubMed · 1452983

Ni-Cds: the memory lingers on.

R S Skinner

View original source ↗Export metadata ↓

Abstract

The medical photographer's source of power for portable electronic flash has evolved from the disposable, single-use battery via the wet cell to the nickel-cadmium rechargeable battery, and recently to the 'dry-fit' rechargeable battery. This paper looks at the ubiquitous nickel-cadmium rechargeable battery with reference to its charge/discharge cycling and chemical 'memory' during discharge, and compares single-use and other rechargeable batteries with respect to ease of use, capacity and working life.

Explore related subjects

Electric Power Supplies Electronics Equipment Design Photography Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

R S Skinner. 1992. Ni-Cds: the memory lingers on.. https://doi.org/10.3109/17453059209051377

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Enhanced charge-collection efficiencies and light scattering in dye-sensitized solar cells using oriented TiO2 nanotubes arrays.

We report on the microstructure and dynamics of electron transport and recombination in dye-sensitized solar cells (DSSCs) incorporating oriented TiO2 nanotube (NT) arrays. The morphology of the NT arrays, which were prepared from electrochemically anodized Ti foils, were characterized by scanning and transmission electron microscopies. The arrays were found to consist of closely packed NTs, several micrometers in length, with typical wall thicknesses and intertube spacings of 8-10 nm and pore diameters of about 30 nm. The calcined material was fully crystalline with individual NTs consisting of about 30 nm sized crystallites. The transport and recombination properties of the NT and nanoparticle (NP) films used in DSSCs were studied by frequency-resolved modulated photocurrent/photovoltage spectroscopies. While both morphologies display comparable transport times, recombination was much slower in the NT films, indicating that the NT-based DSSCs have significantly higher charge-collection efficiencies than their NP-based counterparts. Dye molecules were shown to cover both the interior and exterior walls of the NTs. Analysis of photocurrent measurements indicates that the light-harvesting efficiencies of NT-based DSSCs were higher than those found for DSSCs incorporating NPs owing to stronger internal light-scattering effects.

Electric Power Supplies↗

PubMed2007

Intermediate-band solar cells employing quantum dots embedded in an energy fence barrier.

Power efficiencies>60% have been predicted for idealized quantum dot (QD) intermediate band solar cells. This goal has not yet been realized, due in part to nonidealities that result in charge trapping followed by recombination of photocarriers in the QDs, and the lack of an optimal materials combination. To eliminate charge trapping, a p+-i-n+ cell employing QDs buried within a high band gap barrier layer is proposed and analyzed. The maximum solar power conversion efficiency under AM1.5 spectral radiation of an example GaAs-based photovoltaic cell employing 10-20 layers of InAs QDs surrounded by AlxGa1-xAs barriers in the junction built-in depletion region can be as high as 45%. Higher efficiencies are anticipated for InP-based cells. This represents a significant improvement over GaAs homojunction cells with maximum efficiencies of <25%.

Electric Power Supplies↗

PubMed2006

Electricity generation and microbial community analysis of alcohol powered microbial fuel cells.

Two different microbial fuel cell (MFC) configurations were investigated for electricity production from ethanol and methanol: a two-chambered, aqueous-cathode MFC; and a single-chamber direct-air cathode MFC. Electricity was generated in the two-chamber system at a maximum power density typical of this system (40+/-2 mW/m2) and a Coulombic efficiency (CE) ranging from 42% to 61% using ethanol. When bacteria were transferred into a single-chamber MFC known to produce higher power densities with different substrates, the maximum power density increased to 488+/-12 mW/m2 (CE = 10%) with ethanol. The voltage generated exhibited saturation kinetics as a function of ethanol concentration in the two-chambered MFC, with a half-saturation constant (Ks) of 4.86 mM. Methanol was also examined as a possible substrate, but it did not result in appreciable electricity generation. Analysis of the anode biofilm and suspension from a two-chamber MFC with ethanol using 16S rDNA-based techniques indicated that bacteria with sequences similar to Proteobacterium Core-1 (33.3% of clone library sequences), Azoarcus sp. (17.4%), and Desulfuromonas sp. M76 (15.9%) were significant members of the anode chamber community. These results indicate that ethanol can be used for sustained electricity generation at room temperature using bacteria on the anode in a MFC.

Electric Power Supplies↗