Dual functions of gradient phosphate polyanion doping on improving the electrochemical performance of Ni-rich LiNi0.6Co0.2Mn0.2O2 cathode at high cut-off voltage and high temperature

Ran, Qiwen; Zhao, Hongyuan; Wang, Qiao; Shu, Xiaohui; Hu, Youzuo; Hao, Shuai; Wang, Mei; Liu, Jintao; Zhang, Meiling; Li, Hao; Liu, Ningyang; Liu, Xingquan

doi:10.1016/j.electacta.2019.01.082

Cited by 81 publications

(35 citation statements)

References 50 publications

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“…In Figure (a), the voltage profile at the first cycle for the bare NCM displays a charge/discharge capacity of 226.7/199.1 mAh g −1 at 0.1 C, and the coulombic efficiency (CE) is 87.9 %. A low CE value in the initial cycle is attributed to irreversible capacity owing to the formation of the CEI layer at the NCM surface, and it also can be found in previous reports . The following two cycles exhibit identical curves to the first cycle, and the capacities of the two cycles are 203.7/196.3 and 204.2/196.9 mAh g −1 with CEs of 96.3 and 96.4 %, respectively.…”

Section: Resultssupporting

confidence: 80%

“…X‐ray photoelectron spectroscopy (XPS) surface analysis was conducted to compare the surface compositions of the cathode material after each coating process. As shown in Figure (d), the spectrum of the bare NCM powder in the range of 0–1400 eV shows peaks of Ni 2p (850–895 eV), Co 2p (775–805 eV), and Mn 2p (635–665 eV), which are included in the Ni‐rich layered oxide, and the O 1s (525–535 eV) peak reveals the highest intensity in the spectrum . For the PNCM powder, Ni 2p, Co 2p, and Mn 2p peaks are observed but of very low intensities, owing to the PDA layer finely covering the surface.…”

Section: Resultsmentioning

confidence: 90%

“…According to the previous report, surface degradations originated by electrolyte decomposition are accelerated at an elevated temperature. Therefore, the cycling performance at 60 °C was tested for the electrodes.…”

Section: Resultsmentioning

confidence: 96%

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Selective TiO₂ Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

et al. 2019

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Ni‐rich layered oxides are promising cathode materials for developing high‐energy lithium‐ion batteries. To overcome the major challenge of surface degradation, a TiO2 surface coating based on polydopamine (PDA) modification was investigated in this study. The PDA precoating layer had abundant OH catechol groups, which attracted Ti(OEt)4 molecules in ethanol solvent and contributed towards obtaining a uniform TiO2 nanolayer after calcination. Owing to the uniform coating of the TiO2 nanolayer, TiO2‐coated PDA‐LiNi0.6Co0.2Mn0.2O2 (TiO2‐PNCM) displayed an excellent electrochemical stability during cycling under high voltage (3.0–4.5 V vs. Li+/Li), during which the cathode material undergoes a highly oxidative charge process. In addition, TiO2‐PNCM exhibited excellent cyclability at elevated temperature (60 °C) compared with the bare NCM. The surface degradation of the Ni‐rich cathode material, which is accelerated under harsh cycling conditions, was effectively suppressed after the formation of an ultra‐thin TiO2 coating layer.

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Section: Resultssupporting

confidence: 80%

Section: Resultsmentioning

confidence: 90%

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Selective TiO₂ Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

et al. 2019

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“…Inductively coupled plasma-atomic emission spectroscopy (ICP-AES or ICP) is a cutting-edge technique that can provide relatively precise information on the amounts of Li [132], transition metals [133][134][135] and impurities in examined samples in which concentrations can be indicated by the intensity of characteristic waves emitted from excited atoms or ions. In addition, changes in the elemental composition of electrodes or powder samples due to operation or modification can be reflected in ICP-AES data and the results (in ppm) are often compared with theoretical values or results obtained by using other elemental analysis tools to observe differences.…”

Section: Chemical Analysismentioning

confidence: 99%

Degradation Mechanisms and Mitigation Strategies of Nickel-Rich NMC-Based Lithium-Ion Batteries

Yuan

Zhang

et al. 2019

Electrochem. Energ. Rev.

486

383

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The demand for lithium-ion batteries (LIBs) with high mass-specific capacities, high rate capabilities and long-term cyclabilities is driving the research and development of LIBs with nickel-rich NMC (LiNi x Mn y Co 1−x−y O 2 , x ⩾ 0.5 ) cathodes and graphite (Li x C 6 ) anodes. Based on this, this review will summarize recently reported and widely recognized studies of the degradation mechanisms of Ni-rich NMC cathodes and graphite anodes. And with a broad collection of proposed mechanisms on both atomic and micrometer scales, this review can supplement previous degradation studies of Ni-rich NMC batteries. In addition, this review will categorize advanced mitigation strategies for both electrodes based on different modifications in which Ni-rich NMC cathode improvement strategies involve dopants, gradient layers, surface coatings, carbon matrixes and advanced synthesis methods, whereas graphite anode improvement strategies involve surface coatings, charge/discharge protocols and electrolyte volume estimations. Electrolyte components that can facilitate the stabilization of anodic solid electrolyte interfaces are also reviewed, and trade-offs between modification techniques as well as controversies are discussed for a deeper understanding of the mitigation strategies of Ni-rich NMC/graphite LIBs. Furthermore, this review will present various physical and electrochemical diagnostic tools that are vital in the elucidation of degradation mechanisms during operation to supplement future degradation studies. Finally, this review will summarize current research focuses and propose future research directions.

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“…[116] Ran et al reported a Li 3 PO 4 coating/gradient phosphate polyanion doping in NCM622 and dramatically improved the cycle stability under high-voltage and high-temperature cycling. [117] More recently, using spectroscopic analysis, atomic level imaging and DFT simulation, Zou et al revealed that Al dopants in LiNi 0.92 Co 0.06 Al 0.02 O 2 cathode are partially dissolved in the bulk lattice with a tendency of enrichment near the primary particle surface (Figure 25a). [118] Hence, Al was partitioned into lattice solid solution (<2 at%) at the core of the primary particle and Al 2 O 3 nano-islands (6 at%) on the surface of primary particles.…”

Section: Doping/coatingmentioning

confidence: 99%

Challenges and Strategies to Advance High‐Energy Nickel‐Rich Layered Lithium Transition Metal Oxide Cathodes for Harsh Operation

Liu

Daali

et al. 2020

Adv Funct Materials

187

134

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Nickel-rich layered lithium transition metal oxides (LiNi 1−x−y Co x Mn y O 2 and LiNi 1−x−y Co x Al y O 2 , x + y ≤ 0.2) are the most attractive cathode materials for the next generation lithium-ion batteries for automotive application. However, they suffer from structural/interfacial instability during repeated charge/discharge, resulting in severe performance degradation and serious safety concerns. This work provides a comprehensive review about challenges and strategies to advance nickel-rich layered cathodes specifically for harsh (high-voltage, hightemperature, and fast charging) operations. Firstly, the degradation pathways of nickel-rich cathodes including surface/interface degradation, undesired cathode-electrolytes parasitic reactions, gas evolution, inter/intragranular cracking, and electrical/ionic isolation are discussed. Then, recent achievements in stabilizing the structure/interface of nickel-rich cathodes via surface coating, cation/anion doping, composition tailoring, morphology engineering, and electrolytes optimization are summarized. Moreover, challenges and strategies to improve the performance of Ni-rich cathodes at the electrode level are discussed. Outlook and perspectives to promote the practical application of nickel-rich layered cathodes toward automotive application are provided as well.

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Dual functions of gradient phosphate polyanion doping on improving the electrochemical performance of Ni-rich LiNi0.6Co0.2Mn0.2O2 cathode at high cut-off voltage and high temperature

Cited by 81 publications

References 50 publications

Selective TiO₂ Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

Selective TiO₂ Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

Degradation Mechanisms and Mitigation Strategies of Nickel-Rich NMC-Based Lithium-Ion Batteries

Challenges and Strategies to Advance High‐Energy Nickel‐Rich Layered Lithium Transition Metal Oxide Cathodes for Harsh Operation

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Dual functions of gradient phosphate polyanion doping on improving the electrochemical performance of Ni-rich LiNi0.6Co0.2Mn0.2O2 cathode at high cut-off voltage and high temperature

Cited by 81 publications

References 50 publications

Selective TiO2 Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

Selective TiO2 Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

Degradation Mechanisms and Mitigation Strategies of Nickel-Rich NMC-Based Lithium-Ion Batteries

Challenges and Strategies to Advance High‐Energy Nickel‐Rich Layered Lithium Transition Metal Oxide Cathodes for Harsh Operation

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Selective TiO₂ Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides

Selective TiO₂ Nanolayer Coating by Polydopamine Modification for Highly Stable Ni‐Rich Layered Oxides