Atomic Insights into the Enhanced Surface Stability in High Voltage Cathode Materials by Ultrathin Coating

Fang, Xin; Lin, Feng; Nordlund, Dennis; Mecklenburg, Matthew; Ge, Mingyuan; Rong, Jiepeng; Zhang, Anyi; Chun-lin, Shen; Liu, Yihang; Cao, Yu; Doeff, Marca M.; Zhou, Chongwu

doi:10.1002/adfm.201602873

Cited by 38 publications

(20 citation statements)

References 65 publications

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“…To this end, certain strategies, such as partial Ti substitution [7][8][9]54 and coatings, 55 as well as the use of electrolyte additives 56 should prove useful.…”

Section: Resultsmentioning

confidence: 99%

Depth-Dependent Redox Behavior of LiNi_0.6Mn_0.2Co_0.2O₂

Tian

Nordlund

Xin

et al. 2018

J. Electrochem. Soc.

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128

125

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Nickel-rich layered materials are emerging as cathodes of choice for next-generation high energy density lithium ion batteries intended for electric vehicles. This is because of their higher practical capacities compared to compositions with lower Ni content, as well as the potential for lower raw materials cost. The higher practical capacity of these materials comes at the expense of shorter cycle life, however, due to undesirable structure and chemical transformations, especially at particle surfaces. To understand these changes more fully, the charge compensation mechanism and bulk and surface structural changes of LiNi 0.6 Mn 0.2 Co 0.2 O 2 were probed using synchrotron techniques and electron energy loss spectroscopy in this study. In the bulk, both the crystal and electronic structure changes are reversible upon cycling to high voltages, whereas particle surfaces undergo significant reduction and structural reconstruction. While Ni is the major contributor to charge compensation, Co and O (through transition metal-oxygen hybridization) are also redox active. An important finding from depth-dependent transition metal L-edge and O K-edge X-ray spectroscopy is that oxygen redox activity exhibits depth-dependent characteristics. This likely drives the structural and chemical transformations observed at particle surfaces in Ni-rich materials. The need for lithium-ion batteries with higher energy density and lower cost than currently available, particularly for transport applications, has led to intensified interest in Ni-rich NMC (LiNi x Mn y Co z O 2 ; x+y+z≈1, where x>y) cathode materials.1-5 These materials deliver higher practical capacities in a typically used voltage range than NMCs with lower Ni content (e.g., LiNi 1/3 Mn 1/3 Co 1/3 O 2 or NMC-333), and most formulations contain less of the expensive Co component, reducing raw material costs. The increase in practical capacity roughly scales with the Ni content, but comes at the expense of cycle life and thermal stability at high states-of-charge (SOC). 6 To circumvent these problems, several different strategies have been utilized to improve cycling, particularly to higher potentials. These include partial substitution with Ti 7-9 or Zr, 10 engineering the micro-or nano-structure to reduce surface Ni content using metal segregation, 11 surface pillared structures, 12 and concentration gradients, 13 coating particle surfaces, 14 and development of electrolyte additives. 15,16 While all of these approaches have resulted in improvements, further understanding of the factors that lead to capacity fading is clearly needed in order to meet the stringent performance requirements of traction applications.The formation of a resistive cathode/electrolyte interphase (CEI), such as an electrolyte decomposition layer, has been observed during cycling of LiNi 0. 20 In the study of NMC-532, it was found that surface reconstruction to a rock salt phase dominates when high voltage (4.8 V) cutoffs are used due to oxygen loss under the highly oxidizing conditions, while ...

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“…To this end, certain strategies, such as partial Ti substitution [7][8][9]54 and coatings, 55 as well as the use of electrolyte additives 56 should prove useful.…”

Section: Resultsmentioning

confidence: 99%

Depth-Dependent Redox Behavior of LiNi_0.6Mn_0.2Co_0.2O₂

Tian

Nordlund

Xin

et al. 2018

J. Electrochem. Soc.

Self Cite

128

125

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“…Interestingly, first‐principle calculations also demonstrated that the oxygen release from the cathode can only be suppressed by the lithiated phase of Al 2 O 3 , which forms naturally when the alumina‐coated cathode particles are cycled (Figure B) . Moreover, employing advanced characterization tools such as STEM‐EELS, researchers could demonstrate that Al 2 O 3 coating can suppress the reduction of transition metal cations at the surface of the cathode particles, which denotes to the suppression of the oxygen release from the cathode surface . It was also demonstrated that, upon alumina coating of LiCoO 2 , a portion of Al from the coating layer diffuses to the surface layer of the cathode.…”

Section: Strategies To Improve the Structural Stability Of The Cathodesmentioning

confidence: 97%

Oxygen Release Degradation in Li‐Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches

Sharifi‐Asl

Lü

Amine

et al. 2019

Advanced Energy Materials

311

221

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Widespread application of Li‐ion batteries (LIBs) in large‐scale transportation and grid storage systems requires highly stable and safe performance of the batteries in prolonged and diverse service conditions. Oxygen release from oxygen‐containing positive electrode materials is one of the major structural degradations resulting in rapid capacity/voltage fading of the battery and triggering the parasitic thermal runaway events. Herein, the authors summarize the recent progress in understanding the mechanisms of the oxygen release phenomena and correlative structural degradations observed in four major groups of cathode materials: layered, spinel, olivine, and Li‐rich cathodes. In addition, the engineering and materials design approaches that improve the structural integrity of the cathode materials and minimize the detrimental O2 evolution reaction are summarized. The authors believe that this review can guide researchers on developing mitigation strategies for the design of next‐generation oxygen‐containing cathode materials where the oxygen release is no longer a major degradation issue.

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“…The coating layer can significantly reduce the interface resistance and provide more channels for Na + diffusion, thereby elevating the kinetics of PTCD. [54] Among the three metal oxides, Ti-PTCD exhibited considerably improved capacity retention at high current rates compared to pristine PTCD. The rate performance of PTCD increases in the following order: pristine < ZnO < Al 2 O 3 < TiO 2 .…”

Section: Resultsmentioning

confidence: 98%

Nanoengineered Organic Electrodes for Highly Durable and Ultrafast Cycling of Organic Sodium‐Ion Batteries

Thangavel

Moorthy

Ganesan

et al. 2020

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applied in commercial electric and hybrid electric vehicles. However, the increasing market demand for rechargeable LIBs has increased the concerns regarding the economic sustainability of the LIB technology owing to uneven geographical distribution and relatively low amount of available lithium resources. [1-3] Thus, battery technologies based on abundant and inexpensive resources shall be an important option for large-scale energy storage devices. In this context, sodium-ion battery (SIB) technologies have emerged as a promising and low-cost alternative to LIBs. An intercalation-based chemical mechanism, similar to that of their LIB counterparts, wide sodium resource availability, and excellent electrochemical performance make SIBs an attractive candidate technology for large-scale storage devices. A variety of electrode materials such as layered oxides, polyanions, and fluorophosphates were successfully studied as cathodes for SIBs. [4,5] Although graphite does not offer a favorable Na + intercalation chemistry, several metal sulfides, metals, phosphides, alloys, and hard carbon were investigated as anodes for SIBs. [6-8] The limited capacity of metal oxides, poor cycle life, high cost of hard carbon, and large volume expansion of alloy/metal type anodes limit their practical application. [9,10] Transferring the experience gained from current LIBs to SIBs may lead to the rapid commercialization of the SIB technology. The most studied electrode materials in both LIBs and SIBs are based on transition metal-based chemistries using metal elements that are generally nonrenewable resources. Furthermore, the highly toxic nature of transition metals and high energy consumption involved in metal mining must be addressed to increase the sustainability and environment friendliness of energy storage devices. [11-13] Organic materials are promising candidates for further advancing the sustainability and ecofriendliness of energy storage devices. Organic electrode materials offer many advantages because they mostly consist of light elements such as C, H, O, N, and S. First, organic electrode materials are directly available from natural resources or can be prepared from natural derivatives. [14,15] Organic electrodes have good structural flexibility and wide chemical diversity; further, they can provide a high specific capacity and high voltage at low Sodium-ion batteries (SIBs) have become increasingly important as next-generation energy storage systems for application in large-scale energy storage. It is very crucial to develop an eco-friendly and green SIB technique with superior performance for sustainable future use. Replacing the conventional inorganic electrode materials with green and safe organic electrodes will be a promising approach. However, the poor electrochemical kinetics, unstable electrode-electrolyte interface, high solubility of the electrodes in the electrolyte, and large amount of conductive carbon present great challenges for organic SIBs. In this study, the issues of organic electrodes are addressed ...

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Atomic Insights into the Enhanced Surface Stability in High Voltage Cathode Materials by Ultrathin Coating

Cited by 38 publications

References 65 publications

Depth-Dependent Redox Behavior of LiNi_0.6Mn_0.2Co_0.2O₂

Depth-Dependent Redox Behavior of LiNi_0.6Mn_0.2Co_0.2O₂

Oxygen Release Degradation in Li‐Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches

Nanoengineered Organic Electrodes for Highly Durable and Ultrafast Cycling of Organic Sodium‐Ion Batteries

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Atomic Insights into the Enhanced Surface Stability in High Voltage Cathode Materials by Ultrathin Coating

Cited by 38 publications

References 65 publications

Depth-Dependent Redox Behavior of LiNi0.6Mn0.2Co0.2O2

Depth-Dependent Redox Behavior of LiNi0.6Mn0.2Co0.2O2

Oxygen Release Degradation in Li‐Ion Battery Cathode Materials: Mechanisms and Mitigating Approaches

Nanoengineered Organic Electrodes for Highly Durable and Ultrafast Cycling of Organic Sodium‐Ion Batteries

Contact Info

Product

Resources

About

Depth-Dependent Redox Behavior of LiNi_0.6Mn_0.2Co_0.2O₂

Depth-Dependent Redox Behavior of LiNi_0.6Mn_0.2Co_0.2O₂