Process charge-discharge

The charge-discharge process can be repeated quite often, since the decisive parameters, solubility and dissolution rate of the various compounds, are well matched in the lead-acid battery system. The chemical conversions occur close to each other, and most of the material transport takes place in the micrometer range. Nevertheless, a gradual disintegration of the active material is observed. 

In active material of both electrodes of the EC with purely double electric layer , volume changes do not take place during charge-discharge processes. That s why it is not expedient to add binder into active material. 

The character of carbonaceous material s influence on performance of asymmetric EC systems (carbon - NiOx) is more complicated than that of carbon-carbon system. It is determined by the higher operating potential of NiOx electrode, due to which oxidation and volume changes in electrode active mass upon charge-discharge processes are taking place as the reaction of transformation of Ni(OH)2 into NiOOH is occurring. 

In order to see how the electrode thickness might be optimized in order to provide the lowest electrode resistivity, we have developed a theoretical model to describe the charge/discharge processes in porous carbon electrodes. As a first approximation, let us consider an electrode having two sets of cylindrical pores, namely, nanopores (NP) of less than 3 nm in diameter and transport channels (TC) of more than 20 nm in diameter, with each nanopore having an exit to only one TC. ... 

Besides, the anomalous elastic-plastic characteristics of TEG are the important factors for application as a support. Due to these characteristics TEG-based matrix could accumulate the possible volume changes of metallic component at their cyclic changes during charge/discharge process. 

A typical lithium-ion cell consists of a positive electrode composed of a thin layer of powdered metal oxide (e.g., LiCo02) mounted on aluminum foil and a negative electrode formed from a thin layer of powdered graphite, or certain other carbons, mounted on a copper foil. The two electrodes are separated by a porous plastic film soaked typically in LiPFe dissolved in a mixture of organic solvents such as ethylene carbonate (EC), ethyl methyl carbonate (EMC), or diethyl carbonate (DEC). In the charge/ discharge process, lithium ions are inserted or extracted from the interstitial space between atomic layers within the active materials. 

Properties of lead-acid cells, important from the practical point of view, related, for example, to charge/discharge process and its mechanism, conductivity, and so on are studied using different electrochemical techniques, the most powerful one being electrochemical impedance spectroscopy [355-358]. 

A schematic charge-discharge processes and the overall reaction of a lithium-ion battery using carbon (neg-... 

Conducting polymers are promising electrode materials because the kinetics of the charge-discharge process, i.e., the doping-undoping, is generally fast because... 

Redox conductivity of conducting polymers involves anion insertion associated to oxidation processes (p-type doping) and cation insertion coupled with reduction ones (n-type doping). Efficient polymer-based electronic devices require lowering of the redox potential of the involved electron transfer processes, and electrochemical reversibility is necessary to allow repetitive charge/discharge processes. In the... 

---