Inhomogeneous Degradation of Graphite Anodes in Li-Ion Cells: A Postmortem Study Using Glow Discharge Optical Emission Spectroscopy (GD-OES)

Ghanbari, Niloofar; Waldmann, Thomas; Kasper, Michael; Axmann, Peter; Wohlfahrt‐Mehrens, Margret

doi:10.1021/acs.jpcc.6b07117

Cited by 71 publications

(105 citation statements)

References 50 publications

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“…The SEM images are in agreement with the GD-OES measurements and the photograph in Figure 4a and with literature on fresh cells. 20,44,47 As expected, no aging effects are visible in the fresh cell from optical inspection, GD-OES, and SEM measurements. Figure 4c shows the GD-OES analysis of the cell cycled at 0 • C. The P peak shows a nearly constant distribution through the anode.…”

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325supporting

confidence: 76%

“…16,27,47,51 This fits to the optical appearance of the anode which is black (see inset of Figure 4e). We note that the adhesion of the anode coating from the cell cycled at 45…”

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325supporting

confidence: 65%

“…47,48 Indeed, an estimation based on the Li and O depth profile 47 revealed that Li metal is present in this sample. This fits to the optical appearance of the anode which is shiny and metallic (see inset of Figure 4c).…”

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325mentioning

confidence: 83%

“…The peak maximum of the Li peak is typical for the initial SEI and in consistence with our previous findings for 1.5 Ah and 16 Ah cells with different graphite anodes. 27,47 The inset of Figure 4a shows a photograph of the anode inside the glove box. As expected, for a graphite anode from a discharged fresh cell, a black color was observed.…”

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325mentioning

confidence: 99%

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Electrochemical, Post-Mortem, and ARC Analysis of Li-Ion Cell Safety in Second-Life Applications

Waldmann

Quinn

Richter

et al. 2017

J. Electrochem. Soc.

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Li-ion cells are used in a variety of mobile and stationary applications. Their use must be safe under all conditions, even for aged cells in second-life applications. In the present study, different aging mechanisms are taken into account for accelerating rate calorimetry (ARC) tests. 18650-type cells are cycled at 0 • C (Li plating expected) and at 45 • C (SEI growth expected). After extensive evaluation of the electrochemical results (voltage curve analysis, capacity fade, energy fade, Coulombic efficiency), the cells are tested by PostMortem analysis (CT, GD-OES, SEM) to reveal the main aging mechanisms and by ARC to test the safety behavior. Besides typical ARC results such as onset-of-self-heating, onset-of-thermal runaway and maximum temperatures, as well as acoustic responses of thermal runaway are evaluated and a method is developed to compare fresh cells and cells aged until different SOHs. It turns out that the safety of aged cells is not simply a function of the SOH. However, safety is strongly affected by the main aging mechanism and to the history of operating parameters during the life-time of the cell. Driven by the demand for higher capacity, lower volume, and lower weight, Li-ion technology was developed in the 1980s.1,2 Nowadays, Li-ion technology is used for energy storage in a large variety of applications, e.g. smartphones, tablets, or drones. In particular, electric vehicles in combination with renewable energy sources are promising for reducing climate change and the corresponding glacier melting and sea level rise which is influenced by burning fossil fuels.3-6 For all applications, the safety behavior under all specified operating conditions is most important.7-9 The same is true for aged Li-ion cells used in second-life applications, for example cells which are utilized in stationary energy storage applications after their usage in electric cars.In the past, failure of Li-ion cells led to product recalls which are very expensive for the manufacturers and unsettle customers, even if such incidents happen only in very few cases (ppm range).10 At the moment, safety tests have to be performed with Li-ion prototypes cells before market release. In these tests, fresh cells are always used, however, aged cells are usually neglected. Even if fresh cells show an acceptable safety behavior, this can change for aged cells. 7,[11][12][13][14][15] While some authors observed decreases for certain safety properties, 7,11,12 others found improvements. 12,13,15 It is well known that aging mechanisms change the properties of the materials inside Li-ion cells. [16][17][18][19] Operating conditions and materials have a strong influence on these aging mechanisms. 12,[20][21][22][23] We recently reported on a change of the aging mechanism with temperature for cycling aging of commercial 18650-type cells with graphite anodes and NMC/LMO cathodes. 20 This mechanism change is expressed by a V-shape in Arrhenius plots of the capacity fade rates obtained from cycling at different ambient temperatures. 20 This c...

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Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325supporting

confidence: 76%

“…16,27,47,51 This fits to the optical appearance of the anode which is black (see inset of Figure 4e). We note that the adhesion of the anode coating from the cell cycled at 45…”

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325supporting

confidence: 65%

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325mentioning

confidence: 83%

Section: Post-mortem Analysis Reveals Different Aging Mechanisms In 325mentioning

confidence: 99%

See 2 more Smart Citations

Electrochemical, Post-Mortem, and ARC Analysis of Li-Ion Cell Safety in Second-Life Applications

Waldmann

Quinn

Richter

et al. 2017

J. Electrochem. Soc.

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“…An SEM image of an anode after disassemblyo facell cycled 100 times with ac harging C-rate of 0.75 Ca tÀ21 8Ci ss hown in Figure 3i.T he graphite particles were covered by aL if ilm, which was in agreement with the neutrond iffraction and electrochemical data obtained under similar conditions (À21 8C, 0.75 Cc harging). The deposited Li was not dendritic,w hich has previously been observed for another cell type, [33] most likely because of the pressure in the cylindrical cells and reaction with electrolyte.…”

Section: Relaxationmechanism After Charging In Fresh Cellsmentioning

confidence: 66%

Low‐Temperature Charging and Aging Mechanisms of Si/C Composite Anodes in Li‐Ion Batteries: An Operando Neutron Scattering Study

et al. 2019

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The addition of Si compounds to graphite anodes has become an attractive way of increasing the practical specific energies in Li‐ion cells. Previous studies involving Si/C anodes lacked direct insight into the processes occurring in full cells during low‐temperature operation. In this study, a powerful combination of operando neutron diffraction, electrochemical tests, and post‐mortem analysis is used for the investigation of Li‐ion cells. 18650‐type cylindrical cells in two different aging states are investigated by operando neutron diffraction. The experiments reveal deep insights and important trends in low‐temperature charging mechanisms involving intercalation, alloying, Li metal deposition, and relaxation processes as a function of charging C‐rates and temperatures. Additionally, the main aging mechanism caused by long‐term cycling and interesting synergistic effects of Si and graphite are elucidated.

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Insight Understanding of External Pressure on Lithium Plating in Commercial Lithium‐Ion Batteries

Yu,

Wang,

Zhang

et al. 2024

Adv Funct Materials

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Lithium‐ion batteries (LIBs), as efficient electrochemical energy storage devices, have been successfully commercialized. Lithium plating at anodes has been attracting increasing attention as batteries advance toward high energy density and large size, given its pivotal role in affecting the lifespan, safety, and fast‐charging performance of LIBs. Lithium plating mostly happens during fast charging or charging at low temperatures. However, external pressure is often overlooked as an essential factor that influences lithium plating in LIBs. This review analyzes and discusses the influence of external pressure on performance for commercial LIBs, with a particular focus on lithium plating. Recent advances in this topic, including experimental results and mechanism analyses, are reviewed. Lithium plating is explored by examining the influence of pressure on the internal morphology and electrochemical behavior of batteries. It is emphasized that external pressure affects performance through ion transport, electron transport, and their heterogeneities, thereby increasing the risk of lithium plating in batteries. Subsequently, the rationale for external pressure mitigating lithium plating is elucidated from the perspective of the morphology optimization inside LIBs. Overall, this review provides valuable insights into the role of external pressure on lithium plating in commercial LIBs, practically guiding their rational design and development.

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Inhomogeneous Degradation of Graphite Anodes in Li-Ion Cells: A Postmortem Study Using Glow Discharge Optical Emission Spectroscopy (GD-OES)

Cited by 71 publications

References 50 publications

Electrochemical, Post-Mortem, and ARC Analysis of Li-Ion Cell Safety in Second-Life Applications

Electrochemical, Post-Mortem, and ARC Analysis of Li-Ion Cell Safety in Second-Life Applications

Low‐Temperature Charging and Aging Mechanisms of Si/C Composite Anodes in Li‐Ion Batteries: An Operando Neutron Scattering Study

Insight Understanding of External Pressure on Lithium Plating in Commercial Lithium‐Ion Batteries

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