Perspective on Commercial Li-ion Battery Testing, Best Practices for Simple and Effective Protocols

Dubarry, Matthieu; Baure, George

doi:10.3390/electronics9010152

Cited by 48 publications

(24 citation statements)

References 89 publications

(156 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The twelve cells chosen were within the outlier boundaries of the cell-to-cell variations distribution [36]. The experimental design for this study consisted of six test scenarios, with common conditioning and reference performance tests (RPT) [41], replicated twice.…”

Section: Methodsmentioning

confidence: 99%

“…As described in previous publications [36,41], all cells were subjected to initial conditioning and characterization tests before the beginning of the cycling experiment to verify the quality of cells. Following the conditioning cycles at C/5 and C/2, and before the start of the duty cycle testing, an RPT consisting of C/35, C/5, and C/3 full cycles was performed on all cells.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Durability and Reliability of EV Batteries Under Electric Utility Grid Operations: Impact of Frequency Regulation Usage on Cell Degradation

2020

Self Cite

View full text Add to dashboard Cite

The usage of electric vehicle batteries to assist the main electric grid for the storage of energy provided by intermittent sources should become an essential tool to increase the penetration of green energies. However, this service induces additional usage on the cells and, therefore, could degrade them further. Since degradation is path-dependent, it is of paramount importance to test the impact of all the different grid applications on the batteries. In this work, we tested the additional usage induced by using electric vehicle batteries for frequency regulation at moderate rates during rest or charge and found no detrimental effect after around 2000 cycles on the cells. The main takeaway from our study was that some frequency regulation V2G usage at moderate rates (from C/5 to C/3 as a maximum current) did not accelerate the cell degradation despite close to 15% additional usage. In addition, there was no noticeable difference between performing this ancillary service during rest or charge or at maximum current fluctuations up to C/3 during rest and C/4 during charge. These results are extremely positive for the possible application of V2G/G2V strategies. However, it must be noted that our results hold for these specific cells and the duty cycle tested. More research is necessary to generalize the results. We already verified the results on another batch of commercial cells based on graphite//Nickel Cobalt Aluminum oxide. Due to the lack of differences in the degradation between duty cycles, the benefits of modulating the charge to eliminate the additional usage on the cells could not be verified. Experiments on other chemistries with more aggressive usage will be launched to test the hypothesis further. As for the diagnosis for the degradation, a new approach of coupling IC and DV analysis yielded four indicators for automatic diagnosis. This methodology will allow faster diagnosis and bolsters the value of the FOI approach for BMS implementation. However, our study also showed that under some conditions, in our case the apparent kinetic limitations, some of the FOI may become ineffective with time. Therefore, proper validation using full fits and sensibility analysis to check for the range of efficacy of chosen FOI is still essential. Finally, some cells showcased the 2nd stage of aging and we were not able to predict it from the voltage variations. This suggested that it was not induced by a widespread degradation of the electrodes but was more likely because of localized effects. The cells that did not perform any frequency regulation seemed to be the most affected, but those results need to be moderated by the fact that the differences were probably within what to expect between cells performing the same duty cycles.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Durability and Reliability of EV Batteries Under Electric Utility Grid Operations: Impact of Frequency Regulation Usage on Cell Degradation

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…That might be induced by variations in cell rate capability. Cell No.6 had a smaller capacity than the two adjacent cells and thus showed a lower V d-end at 0.1 C. Inversely, cell No.6 exhibited a larger capacity when C-rate increased to 1 C, indicating that cell No.6 might has better rate capability than the adjacent cells 27,28 . The cells from LG Chem and Lishen also showed similar behavior, as presented in Fig.…”

Section: Cis Application II Rate Dependence Of Cell-to-cell Variatiomentioning

confidence: 97%

“…6(b,c). This indicates that the rate dependence of cell-to-cell variation may provide more information about the battery performance, such as variations in rate capability, which is an important index for cell-to-cell variations 27,28 .…”

Section: Cis Application II Rate Dependence Of Cell-to-cell Variatiomentioning

confidence: 99%

“…Rumpf et al 12 conducted a statistical analysis of parametric cell-to-cell variation of 15 different cell parameters and the correlations between parameters based on 1100 examined cells, and found it necessary to characterize variation in ohmic impedance when determining cell-to-cell variation. Dubarry et al 27,28 have conducted both statistical and electrochemical analyses to characterize cell-to-cell variations, and found that the cell capacity, resistance and rate capability can be regarded as three independent parameters for cell variations evaluation. Furthermore, as cell parameters show different evolution trends during aging, online algorithms are required to evaluate cell-to-cell variation during aging process 15 .…”

mentioning

confidence: 99%

See 1 more Smart Citation

A Facile Approach to High Precision Detection of Cell-to-Cell Variation for Li-ion Batteries

Xie

Ren

Wang

et al. 2020

Sci Rep

View full text Add to dashboard Cite

over the past decade, it has been repeatedly demonstrated that homogeneity in electrochemical performance of lithium-ion cells plays a major role in determining the life and safety of lithium-ion battery modules or packs. Generally, the homogeneity of a battery pack is evaluated by characterizing the cells individually in terms of capacity, mass, impedance. particularly, high quality electrochemical data heavily relies on the availability of high precision current source to minimize the discrepancy induced by the channel-to-channel variation. Here, a facile and precise measurement method is reported for screening cell-to-cell variations, in which voltage is the only indicator parameter independent of high precision current source. in detail, by connecting the cells in series (ciS), the measurement error of electrochemical data caused by stability and discrepancy of current sources among different charge/discharge equipment can be effectively avoided. The findings of this work showed that the cell-to-cell variations can be simply and sensitively detected with CiS configuration. for example, the relative standard deviation, which is the evaluation criterion of battery homogeneity, was 2.14% based on CiS while it was 0.43% based on individual measurements. The simple and precise ciS measurement is promising for evaluation of cell quality or module integration quality. in addition, this work can also provide a solid foundation for the development of detection algorithms for battery management systems to rapidly monitor battery homogeneity.Lithium ion batteries (LIBs) have to be integrated into modules and packs for large-scale applications such as electric vehicles (EVs) and stationary energy storage systems 1-7 . However, a reliable and long-lasting power system is determined mostly by the cell homogeneity rather than the performance of individual cells 8,9 . The cell-to-cell variations in terms of capacity and impedance will subject individual cells to different levels of state of charge (SOC), current, temperature and aging, which in turn would accelerate the degradation of electrochemical performance or even lead to safety performance of the power system 2,10-13 . For instance, a weak cell with a smaller capacity than the average in a series-connected module will be repeatedly overcharged (over-discharged) during charging (discharging) process if the charge/discharge cutoff condition is determined according to the total voltage 14 . The weaker cell will then have faster decay than others and will be susceptible to failure under harsh conditions. The available energy of the module will also be limited by the weakest cell 15 . Therefore, there is an urgent need to understand and minimize the cell-to-cell variations in a battery module.There are different factors leading to variations among cells 11 , including manufacturing factors (manufacturing tolerances, quality control and process design), and environmental factors such as temperature gradient within the battery pack 16 . Rumpf et al. 12 has evaluated the cel...

show abstract

Methods and Instrumentation in Energy Storage

Mishra

Gossage

Sarbapalli

et al. 2021

Encyclopedia of Electrochemistry

View full text Add to dashboard Cite

Electrochemical energy storage systems (EESS), such as batteries, rely on a plethora of dynamic processes including electron and ion transfer, phase transformations, and side reactions, that make their characterization critical toward improving device performance. Both traditional and advanced electroanalytical methods are applied to investigate and evaluate phenomena from the bulk electrode behavior to key interfacial processes, and beyond. Understanding the complexity of energy storage chemistry involves measurements across wide timescales and different spatial dimensions, with high chemical resolution. These demanding characteristics continue to push the development of new analytical instrumentation and methods for better assessment and further improvement of EESS. We discuss the working principles, methods, and instruments needed to evaluate their characteristics and performance. We provide a broad coverage of the electroanalytical principles (e.g. equations, instrumental design, etc.) available for evaluating Li‐ion, redox flow, and other popular EESS. Classical techniques covered include galvanostatic and potentiostatic (dis)charge, cyclic voltammetry, and impedance spectroscopy. We discuss traditional and advanced tools for in situ , operando , and coupled methods to evaluate energy storage materials and the interfacial chemistry under real operating conditions. These include electrochemical methods coupled to nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), neutron‐based methods, X‐ray methods, atomic force microscopy (AFM), and scanning electrochemical microscopy (SECM) to name a few. We hope this introduction to instrumental analysis of EESS is didactical to the novice practitioner and informative to those wishing to expand their knowledge of energy storage.

show abstract

Perspective on Commercial Li-ion Battery Testing, Best Practices for Simple and Effective Protocols

Cited by 48 publications

References 89 publications

Durability and Reliability of EV Batteries Under Electric Utility Grid Operations: Impact of Frequency Regulation Usage on Cell Degradation

Durability and Reliability of EV Batteries Under Electric Utility Grid Operations: Impact of Frequency Regulation Usage on Cell Degradation

A Facile Approach to High Precision Detection of Cell-to-Cell Variation for Li-ion Batteries

Methods and Instrumentation in Energy Storage

Contact Info

Product

Resources

About