Determination Of Degradation Mechanisms Research Articles

Cylindrical Li-Ion Battery State of Health Evaluation by Differential Heat Analysis During Calendar Ageing

A novel method for the state of health (SoH) estimation and determination of the degradation mechanisms of cylindrical Li-ion cells after long storage time is presented. The proposed method is based on differential curves obtained with the help of temperature and heat flux measurements on the surface of a cylindrical lithium iron phosphate (LFP) cell. The applicability and advantages of the proposed differential curves for the SoH estimation and determination of degradation mechanisms are discussed and verified based on a comparison with currently existing in-situ diagnostic methods such as differential voltage (DV) analysis method. The results of the comparison show that the proposed differential curve can provide information about capacity fading and prevailing degradation mechanism at higher than 1 C-rate discharging current while the application of the DV curve may not be possible. Moreover, the presented method allows identification of the changes in the entropic heat generation, which may improve the SoH estimation and the determination of the degradation mechanisms in a cylindrical Li-ion cell after a storage period.

Museum factors affecting the ageing process of organic materials: review on experimental designs and the INVENVORG project as a pilot study

AbstractThe most common way followed for the determination of degradation mechanisms of organic materials is the application of physiochemical methods after accelerated aging. In recent years, there has been a remarkable research activity towards the development of alternative decay determination methods in organic materials based on statistics. We first present a survey of European research projects in this area together with summaries of their results. Second, we describe the ongoing project entitled ‘Investigation of the environmental factor effects on organic materials constituting the natural and cultural heritage’ in which statistics plays a crucial role. In particular, we present a statistical methodology that is based on a designed experimental and inferential protocol which will guide the research throughout the project. By providing basic statistical and design concepts, we present guidelines to design statistical protocols that are necessary for scientifically sound quantitative experiments.