Browsing by Subject "Electrochemical noise"

Now showing 1 - 3 of 3

Open Access
Analysis of electrochemical noise in NiCd batteries throughout their lifetime
(TUBITAK, 2018) Ülgüt, Burak
Electrochemical noise measurements have been applied to electrochemical systems that show stochastic behavior. The standard area of study that benefits from this stochastic analysis is localized corrosion modes like pitting and crevice corrosion. Application of electrochemical noise measurements to battery systems, though rare, is recently becoming more popular. The present contribution first establishes a method of analyzing electrochemical voltage noise data for NiCd batteries, then follows four samples of batteries in terms of voltage noise throughout their lifetimes. The noises exhibited by battery systems are small, but finite. This noise is expected to be due to variations in the electrochemistry on the electrode surfaces of the battery. After careful analysis, the voltage noise behavior of NiCd batteries does not appear to show a statistically significant variation of electrochemical voltage noise throughout their lifetimes.
Open Access
Electrochemical noise analysis in batteries
(Elsevier, 2022-12-10) Karaoğlu, Gözde; Hatipoğlu, Gizem; Ulgut, Burak
Electrochemical noise is invaluable in the investigations of stochastic electrochemical processes. Though historically it has been applied almost exclusively to crevice and pitting corrosion studies, application to batteries is interesting for basic science and shows a huge potential for non-perturbing real-time sensor development. Given this promise, noise studies on batteries are starting to appear in the literature. In this manuscript, we are going to critically evaluate the small but emerging body of literature and investigate the mathematical methods employed. We will discuss the intricacies of electrochemical noise applied to batteries both in measurements and in analysis in order to initiate a deeper discussion. In conclusion, we argue that reliance on mathematical methods alone is not the answer, as all mathematical methods use require parameters to guide the analysis. Instead, post-mortem characterizations of batteries can guide the understanding of noise signals measured in batteries, guiding potential mathematical analysis methods and their steps.
Open Access
Electrochemical noise investigation of lithium based batteries
(2021-09) Karaoğlu, Gözde
With the widespread use of portable technological devices such as smart phones, laptops, tablets and smart watches, and electric cars in recent years, the need for energy is also increasing. Batteries based on lithium chemistry are the primary choice of the portable technology industry due to their small size, light weight, rechargeability and high energy density, and therefore, the interest in lithium-based batteries has been an important academic research topic. Electrochemical noise measurements are commonly used measurement methods in the corrosion research. In recent years, electrochemical noise measurements have been employed as a non-destructive testing method, especially in lithium-based batteries, but the measurement methods and analyses methods presented in the literature are insufficient. In this thesis, electrochemical noise measurement methods and common analyses methods in lithium-based batteries are summarized, a new approach how to make accurate noise measurement and analysis, and under which conditions lithium-based batteries show noise increase is introduced. The use of lithium alloy as the anode material in rechargeable batteries causes its energy density to be less than the energy density provided by pure metallic lithium used in non-rechargeable batteries. For this reason, the use of pure metallic lithium in rechargeable batteries is extremely important for industrial development. The examination of pure metallic lithium batteries with electrochemical noise, which is a non-destructive measurement method during charging and discharging, and imaging with optical microscope in situ and after death with spectroscopic analysis methods are presented.