Post mortem analysis of fatigue mechanisms in LiNi0.8Co0.15Al0.05O2 – LiNi0.5Co0.2Mn0.3O2 – LiMn2O4/graphite lithium ion batteries

Lang, Michael; Darma, Mariyam Susana Dewi; Kleiner, Karin; Riekehr, Lars; Mereacre, Liuda; Pérez, Marta Ávila; Liebau, Verena; Ehrenberg, Helmut

doi:10.1016/j.jpowsour.2016.07.010

Cited by 67 publications

(52 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[71][72][73] In addition, the microcrack evolution, which is known as main degradation mechanism of the nickel-rich cathode, can lead to the formation of the resistant layer near the cracks. [68,69,74,75] Figure 5c shows the densely packed secondary particle of LiNi 0.80 Co 0.15 Al 0.05 O 2 (NCA) with the layered structure. However, the microcracks were generated in the cathode inside after 300 cycles at 60 °C, facilitating the phase transition from the layered structure to rock-salt structure (Figure 5d).…”

Section: Structural Stabilitymentioning

confidence: 99%

See 1 more Smart Citation

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Kim

Lee

Cha

et al. 2017

Advanced Energy Materials

644

582

View full text Add to dashboard Cite

practical candidate for the wide application of the LIBs with respect to the reversible capacity, rate capability, and capital cost. [4][5][6][7] In terms of nickel contents, the nickel-rich cathodes with nickel content above 80% have advantages in gravimetric capacity, allowing high gravimetric energy density, compared with the nickel content less than 80%. Currently, the nickel-rich cathodes with the amount of nickel less than 60% are fully commercialized. However, the nickel-rich cathodes with nickel content of ≥80% still have many difficulties in the commercialization with respect to powder properties and electrode fabrication process.The unstable powder properties originate from residual lithium compounds such as LiOH and Li 2 CO 3 that formed by the spontaneous reduction of sensitive trivalent nickel ions during the synthesis process and storage in air. [8][9][10][11] The Li 2 CO 3 significantly promotes the gas evolution and increase the moisture of the cathode powder, which strongly related to the safety issue. [12][13][14] Furthermore, the LiOH on the cathode increases the powder pH value, causing the gelation of the slurry during the electrode fabrication process. The nickel-rich cathode with nickel content of ≤60% have acceptable amount of residual lithium compounds for the practical use. By contrast, the cathode with amount of nickel of ≥80% should be treated by additional process to reduce the residual lithium compounds ( Table 1). Furthermore, other powder properties, such as powder pH and moisture, should be carefully controlled when nickel contents were exceeded of ≥80%. Thus, for the practical application of these cathode materials, most battery companies have adapted the washing process, in which the cathode power was stirred in purified water for 20-40 min. [15,16] The washing process could greatly reduce the residual lithium compounds and powder pH value. [15] However, the washing process not only increases process time and capital cost but also make the nickel-rich cathode more chemically sensitive than nonwashed cathodes. [16] More seriously, the water washing deteriorates the thermal stability of the nickel-rich cathodes, indicating that the washing process should be substituted by other methods for the battery safety.Another important factor for the commercialization of the nickel-rich cathodes is the electrode density directly related to the energy density. In general, the nickel-rich cathodesThe layered nickel-rich cathode materials are considered as promising cathode materials for lithium-ion batteries (LIBs) due to their high reversible capacity and low cost. However, several significant challenges, such as the unstable powder properties and limited electrode density, hindered the practical application of the nickel-rich cathode materials with the nickel content over 80%. Herein, important stability issues and in-depth understanding of the nickel-rich cathode materials on the basis of the industrial electrode fabrication condition for the commercialization of the nickel-rich cathode m...

show abstract

Section: Structural Stabilitymentioning

confidence: 99%

“…In addition, the microcrack evolution, which is known as main degradation mechanism of the nickel‐rich cathode, can lead to the formation of the resistant layer near the cracks . Figure c shows the densely packed secondary particle of LiNi 0.80 Co 0.15 Al 0.05 O 2 (NCA) with the layered structure.…”

Section: Stability Issues Of Nickel‐rich Cathode Materialsmentioning

confidence: 99%

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Kim

Lee

Cha

et al. 2017

Advanced Energy Materials

644

582

View full text Add to dashboard Cite

show abstract

“…Intergranular cracking caused by the inhomogeneity of Li insertion and extraction across the Li‐rich cathode particle surfaces worsens the connectivity of primary particle grains within the secondary Li‐rich cathode particles. [ 45–47 ] This cracking is continuously exacerbated by ongoing electrolyte decomposition, forming a nonuniform interfacial layer at the newly exposed primary cathode surface induced by intergranular cracking. Interfacial engineering using functional electrolyte additives facilitates the reversible electrochemical reaction of Li‐rich cathodes without intergranular cracking.…”

Section: Resultsmentioning

confidence: 99%

An Antiaging Electrolyte Additive for High‐Energy‐Density Lithium‐Ion Batteries

Han

Hwang

Kim

et al. 2020

Advanced Energy Materials

View full text Add to dashboard Cite

critical challenges to be overcome for the successful utilization of Li-rich cathodes in LIBs. Li-rich cathodes suffer from severe voltage decay and continued capacity fading upon repeated cycling mainly because of two unfavorable reactions: 1) the interfacial degradation that stems from an unstable cathode-electrolyte interphase and 2) the irreversible phase transformation from layered to spinel. [9][10][11] Undesirable electrolyte decomposition at the Li-rich cathode with a high operation voltage of 4.4 V versus Li/Li + causes irreparable damage to the cathode-electrolyte interface (CEI), such as inhomogeneous delithiation induced by a nonuniform surface coverage of decomposition byproducts and the consumption of active Li + ions and electrons. [12,13] The second issue, irreversible phase transformation, which is most likely the major reason for voltage decay, is not fully understood. This transformation is closely linked to a reduction in the valence state of transition metal ions in the Li-rich cathode and propagates gradually from the interface to the bulk as the cycle progresses. [11,14] On the basis of the aforementioned reports, at a high voltage, the highly oxidized transition metal ions are prone to take electrons from the electrolyte components to lower their valence state, resulting in their phase transformation from layered to spinel. [15] The formation of a stable CEI by additives can improve the electrochemical performance of Li-rich cathodes while mitigating the sustained occurrence of unfavorable phase transformations through reforming the cathode interface. [16][17][18][19][20] Moreover, the decrease in the valence state of the transition metal ions leads to the release of oxygen (O 2 ) and superoxide radicals (O 2 •− ) to maintain the charge balance in the cathode during subsequent cycling. [21][22][23] Electrochemical activation of Li 2 MnO 3 in a Li-rich cathode above 4.4 V versus Li/Li + on the first charge inevitably evolves reactive oxygen species, including oxygen gas (O 2 ) and superoxide radicals (O 2 •− ), in a cell. [22,24] The reactive superoxide radical (O 2 •− ) generated from the Lirich cathode produces gaseous products such as CO and CO 2 through reaction with the ethylene carbonate (EC) solvent in the electrolyte and accordingly causes a sudden termination of battery operation by electrolyte depletion. [15,25] Therefore, scavenging the reactive oxygen species serves as an effective way to improve the electrochemical performance of Li-rich cathodes.High-capacity Li-rich layered oxide cathodes along with Si-incorporated graphite anodes have high reversible capacity, outperforming the electrode materials used in existing commercial products. Hence, they are potential candidates for the development of high-energy-density lithium-ion batteries (LIBs). However, structural degradation induced by loss of interfacial stability is a roadblock to their practical use. Here, the use of malonic acid-decorated fullerene (MA-C 60 ) with superoxide dismutase activity and water scavenging capabil...

show abstract

“…These include small reflections caused most likely by LiOH, Li2CO3 and LiF. For example, an increase in the amount of LiF on the graphite surface as a result of cycling especially at higher temperatures has been reported in the literature [7,26,40].…”

Section: Analysis Of Thementioning

confidence: 92%

Low-temperature aging mechanisms of commercial graphite/LiFePO4 cells cycled with a simulated electric vehicle load profile—A post-mortem study

Rauhala

Jalkanen

Romann

et al. 2018

Journal of Energy Storage

View full text Add to dashboard Cite

Reduced cycle life is one of the issues hindering the adoption of large lithium-ion battery systems in cold-climate countries. Thus, the aging mechanisms of commercial graphite/LiFePO4 (lithium iron phosphate) cells at low temperatures (room temperature, 0 °C and −18 °C) are investigated here through an extended post-mortem analysis. The cylindrical 2.3 Ah cells were cycled with a simulated battery electric vehicle load profile, and the aged cells were then disassembled inside an argon-filled glove box. A non-cycled cell was also dismantled as a reference. Half-cell testing was utilized to evaluate the degradation of the electrochemical performance of the electrodes, whereas X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, inductively coupled plasma optical emission spectroscopy and Raman spectroscopy were used to characterize the changes in the materials properties. The full-cell performance loss was mostly seen as capacity fade whereas significant changes in the cell impedance were not observed. Depending on the cycling temperature, loss of cyclable lithium due to solid electrolyte interphase growth and/or lithium plating on the graphite electrode were observed, and they are attributed as the main mechanisms responsible for the capacity loss. Furthermore, increased disordering of the graphite electrode was observed for the cell cycled at −18 °C. The graphite disordering was hypothesized to result from diffusion-induced stress and the mechanical stress caused by severe lithium plating. In contrast, the LiFePO4 electrodes showed only minimal signs of degradation regardless of the cycling temperature.

show abstract

Post mortem analysis of fatigue mechanisms in LiNi0.8Co0.15Al0.05O2 – LiNi0.5Co0.2Mn0.3O2 – LiMn2O4/graphite lithium ion batteries

Cited by 67 publications

References 53 publications

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Prospect and Reality of Ni‐Rich Cathode for Commercialization

An Antiaging Electrolyte Additive for High‐Energy‐Density Lithium‐Ion Batteries

Low-temperature aging mechanisms of commercial graphite/LiFePO4 cells cycled with a simulated electric vehicle load profile—A post-mortem study

Contact Info

Product

Resources

About