In Situ Observation of LiNiO[sub 2] Single-Particle Fracture during Li-Ion Extraction and Insertion

Dokko, Kaoru; Nishizawa, Masatoyo; Horikoshi, Soichi; Itoh, Takashi; Mohamedi, Mohamed; Uchida, Isamu

doi:10.1149/1.1390977

Cited by 108 publications

(71 citation statements)

References 9 publications

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“…It also confirms that the capacity loss in the cell is not due showed better capacity retention at 50 o C, although there was still some fatigue of crystal structure. [19][20] Cycling at 100% DOD at 60°C is more severe than has been previously reported for this material. However, other possible degradation mechanisms include loss of electronic conductivity in the cathode by physical changes such as the fracture of particle, segregation between active particle and carbon black, swelling of binder, etc.…”

Section: Electrochemical Analysis Of Cell Componentsmentioning

confidence: 45%

Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature

Shim

Kostecki

Richardson

et al. 2002

Journal of Power Sources

462

223

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Laboratory-size LiNi 0.8 Co 0.15 Al 0.05 O 2 /graphite lithium-ion pouch cells were cycled over 100% DOD at room temperature and 60°C in order to investigate high-temperature degradation mechanisms of this important technology. Capacity fade for the cell was correlated with that for the individual components, using electrochemical analysis of the electrodes and other diagnostic techniques. The high-temperature cell lost 65% of its initial capacity after 140 cycles at 60 o C compared to only 4% loss for the cell cycled at room temperature. Cell ohmic impedance increased significantly with the elevated temperature cycling, resulting in some of loss of capacity at the C/2 rate. However, as determined with slow rate testing of the individual electrodes, the anode retained most of its original capacity, while the cathode lost 65%, even when cycled with a fresh source of lithium.Diagnostic evaluation of cell components including XRD, Raman, CSAFM and suggest capacity loss occurs primarily due to a rise in the impedance of the cathode, especially at the end-of-charge. The impedance rise may be caused in part by a loss of the conductive carbon at the surface of the cathode and/or by an organic film on the surface of the cathode that becomes non-ionically conductive at low lithium content.

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Section: Electrochemical Analysis Of Cell Componentsmentioning

confidence: 45%

Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature

Shim

Kostecki

Richardson

et al. 2002

Journal of Power Sources

462

223

View full text Add to dashboard Cite

show abstract

“…[29][30][31] The fresh LiNi 0. 70 Co 0. 15 Mn 0.15 O 2 (LNCM) cathode revealed clean surface composed of the primary particles with the size of ≈150 nm, whereas the residual lithium compounds were observed in the LNCM after aging in air for 3 months (Figure 1b).…”

Section: Residual Lithium Compoundsmentioning

confidence: 99%

“…[68][69][70] In general, the c-axis increases as the repulsive force between the oxygen slab increases, and the a-axis decreases because of the increase in electrostatic attraction caused by transition metal oxidation during charging process. With increasing the nickel content in the cathode, the evolution of the c-axis lattice parameter was severe because of the extraction of a large amount of the lithium ions (Figure 5a).…”

Section: Structural Stabilitymentioning

confidence: 99%

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Kim

Lee

Cha

et al. 2017

Advanced Energy Materials

665

582

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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...

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“…[12][13][14][15] Consequently, such structural instability causes rapid capacity fading and poor electrochemical performance, which are ascribed to the deteriorated ionic and electronic conduction. [12][13][14][15] Consequently, such structural instability causes rapid capacity fading and poor electrochemical performance, which are ascribed to the deteriorated ionic and electronic conduction.…”

mentioning

confidence: 99%

Self‐Induced Concentration Gradient in Nickel‐Rich Cathodes by Sacrificial Polymeric Bead Clusters for High‐Energy Lithium‐Ion Batteries

Kim

Cho

Jeong

et al. 2017

Advanced Energy Materials

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along the grain boundaries. [12][13][14][15] Consequently, such structural instability causes rapid capacity fading and poor electrochemical performance, which are ascribed to the deteriorated ionic and electronic conduction. To date, many surface treatment and morphology control technologies have been suggested to prevent capacity fading and structure degradation during cycling. [3] For the surface treatment of nickel-based layered cathodes, this concept is considered as a very simple and viable way by introducing additional layers consisting of polymer, [16] metal phosphate, [17,18] metal fluoride, [19,20] metal oxide, [21,22] or core shell [23][24][25] on the surface of the secondary particle clusters. The point that is often overlooked, however, is that these approaches do not fully prevent the fundamental issues related to the grain boundaries among the primary particles. In this context, a novel concept of full concentration-gradient of manganeserich phase with long rod-shaped primary particles was reported and demon strated good structural stability. [26][27][28][29][30] More recently, Cho and co-workers introduced two approaches for the grain boundary coating including the nanoscale surface treatment by cobalt-rich cation mixing layer [31] and spinel-like Li x CoO 2 layer as a glue-nanofiller [32] for highly stable active materials, where an improved structural and thermal stability was achieved by suppressing the phase transition from layered to rock-salt phase of primary particles. However, these kinds of surface treatment methods accompanied a multistep coprecipitation process [29,30] or were carried out after coprecipitation process of active materials by using additional chemicals for surface coatings, [31][32][33] which can cause the increase of the process time and capital cost.Herein, we report a highly stable LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode with a TM concentration gradient in primary particles and inner pores in secondary particles via a simple, one-step coprecipitation method by exploiting polymeric-beads as a sacrificial template without any surface coating reagents. The prepared sample retains the self-induced TM concentration gradient with reduced nickel oxidation state in the primary particles, which significantly improved the structural stability by suppressing the evolution of microcracks in cathode particles at a high voltage cutoff of 4.45 V and even at a high temperature of 60 °C. Additionally, the internal pores in the secondary particles successfully provided a buffer effect against the volume change of the primary particles.The synthesis process for polystyrene beads (PSBs) incorporated LiNi 0.6 Co 0.2 Mn 0.2 O 2 , denoted as a PSB-NCM, is simple and highly scalable. Briefly, the cathode precursor, PSB-Ni 0.6 Co 0.2 Mn 0.2 (OH) 2 , was synthesized by the coprecipitation To meet the demand of electric vehicles and electrical energy storage systems, lithium-ion batteries with high energy density, high rate capability, and thermal stability have been required. [1][2][3] Among the man...

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In Situ Observation of LiNiO[sub 2] Single-Particle Fracture during Li-Ion Extraction and Insertion

Cited by 108 publications

References 9 publications

Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature

Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature

Prospect and Reality of Ni‐Rich Cathode for Commercialization

Self‐Induced Concentration Gradient in Nickel‐Rich Cathodes by Sacrificial Polymeric Bead Clusters for High‐Energy Lithium‐Ion Batteries

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