scholarly journals Twin-assisted cracking degradation in sodium layered oxide cathodes

2021 ◽  
Author(s):  
Cheng Chen ◽  
Zhen Han ◽  
Chaoping Liang ◽  
Yiming Feng ◽  
Peng Wang ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Imaging Spectroscopy ◽  
Mechanical Stimuli ◽  
Layered Oxides ◽  
Crystalline Materials ◽  
High Performing ◽  
Twinning Plane ◽  
Electrochemical Cycling ◽  
Chemical Characters ◽  
Crystallographic Defects

Abstract Twinning defects often present in crystalline materials when are subject to mechanical stimuli and are mostly affecting their physicochemical properties. The twinning formation and twin-related degradation upon cycling in sodium layered oxides (SLOs) are poorly understood. Combining atomic-resolution imaging, spectroscopy and first principles calculations, we reveal that growth twinning is unexpectedly common in the SLO materials and the twin boundaries show distinct structural and chemical characters from those identified in lithium layered oxides. A unique O-P-O twinning plane was identified in the O3 type SLO materials. We discover that twin-assisted Na diffusion cause large volume variations and trigger intragranular fracture during electrochemical cycling. The present findings not only establish a robust correlation between growth twinning and intragranular cracking in SLOs, but also offer general implications for the development of high-performing intercalation electrode materials by regulating crystallographic defects.

scholarly journals Synthetic Pathway Determines the Non-equilibrium Crystallography of Li- and Mn-rich Layered Oxides

2020 ◽  
Author(s):  
Ashok S. Menon ◽  
Seda Ulusoy ◽  
Dickson Ojwang ◽  
Lars Riekehr ◽  
Christophe Didier ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Sol Gel ◽  
Direct Consequence ◽  
Layered Oxides ◽  
High Performing ◽  
In Situ Methods ◽  
Li Ion ◽  
Complementary Techniques ◽  
Multi Phase

Li- and Mn-rich layered oxides show significant promise as electrode materials for future Li-ion batteries. However, accurate descriptions of its crystallography remain elusive, with both single-phase solid solution and multi-phase structures being proposed for high performing materials such as Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2</sub>. Herein, we report the synthesis of single- and multi-phase variants of this material through sol-gel and solid-state methods, respectively, and conclusively demonstrate that its crystallography is a direct consequence of the synthetic route and not an inherent property of the composition, as previously argued. This was accomplished via complementary techniques that probe the bulk and local structure followed by in situ methods to map the synthetic progression. As the electrochemical performance and anionic redox behaviour is often rationalised on the basis of the presumed crystal structure, clarifying the structural ambiguities is an important step towards harnessing its potential as an electrode material.

scholarly journals Synthetic Pathway Determines the Non-equilibrium Crystallography of Li- and Mn-rich Layered Oxides

2020 ◽  
Author(s):  
Ashok S. Menon ◽  
Seda Ulusoy ◽  
Dickson Ojwang ◽  
Lars Riekehr ◽  
Christophe Didier ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Sol Gel ◽  
Direct Consequence ◽  
Layered Oxides ◽  
High Performing ◽  
In Situ Methods ◽  
Li Ion ◽  
Complementary Techniques ◽  
Multi Phase

Li- and Mn-rich layered oxides show significant promise as electrode materials for future Li-ion batteries. However, accurate descriptions of its crystallography remain elusive, with both single-phase solid solution and multi-phase structures being proposed for high performing materials such as Li<sub>1.2</sub>Mn<sub>0.54</sub>Ni<sub>0.13</sub>Co<sub>0.13</sub>O<sub>2</sub>. Herein, we report the synthesis of single- and multi-phase variants of this material through sol-gel and solid-state methods, respectively, and conclusively demonstrate that its crystallography is a direct consequence of the synthetic route and not an inherent property of the composition, as previously argued. This was accomplished via complementary techniques that probe the bulk and local structure followed by in situ methods to map the synthetic progression. As the electrochemical performance and anionic redox behaviour is often rationalised on the basis of the presumed crystal structure, clarifying the structural ambiguities is an important step towards harnessing its potential as an electrode material.

Real-time monitoring of stress development during electrochemical cycling of electrode materials for Li-ion batteries: overview and perspectives

2019 ◽  
Vol 7 (41) ◽  
pp. 23679-23726 ◽  
Author(s):  
Manoj K. Jangid ◽  
Amartya Mukhopadhyay
Keyword(s):  
Real Time ◽  
Electrode Materials ◽  
Electrochemical Potential ◽  
Li Ion Batteries ◽  
Stress Development ◽  
Electrochemical Cycling ◽  
Li Ion ◽  
Real Time Information ◽  
Time Information

Monitoring stress development in electrodes in-situ provides a host of real-time information on electro-chemo-mechanical aspects as functions of SOC and electrochemical potential.

scholarly journals RECENT ADVANCES IN SODIUM INTERCALATION POSITIVE ELECTRODE MATERIALS FOR SODIUM ION BATTERIES

2013 ◽  
Vol 06 (01) ◽  
pp. 1330001 ◽  
Author(s):  
JING XU ◽  
DAE HOE LEE ◽  
YING SHIRLEY MENG
Keyword(s):  
Electrode Materials ◽  
High Energy ◽  
Positive Electrode ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
Significant Progress ◽  
Layered Oxides ◽  
Solid State Physics ◽  
The Past ◽  
Positive Electrode Materials

Significant progress has been achieved in the research on sodium intercalation compounds as positive electrode materials for Na-ion batteries. This paper presents an overview of the breakthroughs in the past decade for developing high energy and high power cathode materials. Two major classes, layered oxides and polyanion compounds, are covered. Their electrochemical performance and the related crystal structure, solid state physics and chemistry are summarized and compared.

scholarly journals Surface Modifications of Positive-Electrode Materials for Lithium Ion Batteries

2019 ◽  
Vol 73 (11) ◽  
pp. 880-893 ◽  
Author(s):  
Nam Hee Kwon ◽  
Joanna Conder ◽  
Mohammed Srout ◽  
Katharina M. Fromm
Keyword(s):  
Lithium Ion Batteries ◽  
Electrode Materials ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Surface Modifications ◽  
Positive Electrode ◽  
Layered Oxides ◽  
Spinel Type ◽  
Surface Modified ◽  
Positive Electrode Materials

Lithium ion batteries are typically based on one of three positive-electrode materials, namely layered oxides, olivine- and spinel-type materials. The structure of any of them is 'resistant' to electrochemical cycling, and thus, often requires modification/post-treatment to improve a certain property, for example, structural stability, ionic and/or electronic conductivity. This review provides an overview of different examples of coatings and surface modifications used for the positive-electrode materials as well as various characterization techniques often chosen to confirm/detect the introduced changes. It also assesses the electrochemical success of the surface-modified positive-electrode materials, thereby highlighting remaining challenges and pitfalls.

scholarly journals Electrochemical Properties of Screen-Printed Carbon Nano-Onion Electrodes

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3884
Author(s):  
Loanda R. Cumba ◽  
Adalberto Camisasca ◽  
Silvia Giordani ◽  
Robert J. Forster
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Limit Of Detection ◽  
Low Cost ◽  
Analytical Sensitivity ◽  
High Performing ◽  
Carbon Particles ◽  
Screen Printed Electrodes ◽  
Ink Formulation ◽  
Screen Printed

The properties of carbon nano-onions (CNOs) make them attractive electrode materials/additives for the development of low-cost, simple to use and highly sensitive Screen Printed Electrodes (SPEs). Here, we report the development of the first CNO-based ink for the fabrication of low-cost and disposable electrodes, leading to high-performance sensors. Achieving a true dispersion of CNOs is intrinsically challenging and a key aspect of the ink formulation. The screen-printing ink formulation is achieved by carefully selecting and optimising the conductive materials (graphite (GRT) and CNOs), the polymer binder, the organic solvent and the plasticiser. Our CNO/GRT-based screen-printed electrodes consist of an interconnected network of conducting carbon particles with a uniform distribution. Electrochemical studies show a heterogeneous electron transfer rate constant of 1.3 ± 0.7 × 10−3 cm·s−1 and a higher current density than the ferrocene/ferrocenium coupled to a commercial graphite SPEs. In addition, the CNO/GRT SPE can detect dopamine in the concentration range of 10.0–99.9 µM with a limit of detection of 0.92 µM (N = 3). They exhibit a higher analytical sensitivity than the commercial graphite-based SPE, with a 4-fold improvement observed. These results open up the possibility of using high-performing CNO-based SPEs for electrochemical applications including sensors, battery electrodes and electrocatalysis.

In situ Raman and UV-Vis spectroscopic analysis of lithium-ion batteries

2015 ◽  
Vol 1773 ◽  
pp. 33-40 ◽  
Author(s):  
Marcel Heber ◽  
Christian Schilling ◽  
Toni Gross ◽  
Christian Hess
Keyword(s):  
Lithium Ion Batteries ◽  
Spectroscopic Analysis ◽  
Electrode Materials ◽  
Lithium Ion ◽  
In Situ Raman ◽  
Spatially Resolved ◽  
Conductive Additives ◽  
Electrochemical Cycling ◽  
Carbon Based

ABSTRACTThe potential of Raman and UV-Vis diagnostics for spatially-resolved and in situ diagnostics of lithium-ion batteries is demonstrated. Regarding the use of in situ Raman diagnostics focus is put on LiCoO2 electrode materials, which were investigated in detail as composites of LiCoO2 with binder and conductive additives. The potential of in situ UV-Vis analysis is illustrated for carbon-based materials showing significant absorption changes during electrochemical cycling due to lithium de-/intercalation.

Oxidation States in Layered Nickel Oxide Based Electrode Materials

1992 ◽  
Vol 293 ◽  
Author(s):  
Claude Delmas
Keyword(s):  
Electrode Materials ◽  
Ligand Field ◽  
Spin Configuration ◽  
Nickel Ions ◽  
Cobalt Ions ◽  
Cationic Distribution ◽  
Cobalt Substitution ◽  
Electrochemical Cycling ◽  
Iron Nickel ◽  
Structural Parts

AbstractNiO2 slabs made of edge-sharing NiO6 octahedra are the main structural parts of the positive electrode materials involved in Ni-Cd, Ni-M- and Li-LiNiO2 secondary batteries. These electrochemical systems are among the best ones for applications. The behavior of all these electrode materials can be optimized by substituting several cations for nickel.The effect of iron and cobalt substitution has been investigated in detail. The oxidation state modifications resulting from the electrochemical cycling have been characterized from magnetic, conductivity, thermoelectric-power and Mössbauer studies. The overall results show that nickel ions are oxidized to the tetravalent state before cobalt ions. More surprisingly, the oxidation of iron-nickel mixed phases shows the simultaneous presence of tetravalent iron and nickel ions in the low spin configuration. For the first time, in situ M6ssbauer measurements have been performed during the cycling of a nickel-cadmium cell.This cationic distribution results from the competition between the intrinsic redox properties of the 3d cations and the accommodation of the oxidation levels to the ligand field imposed by the prevailing cation.

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