Asymmetric pathways in the electrochemical conversion reaction of NiO as battery electrode with high storage capacity

Boesenberg, Ulrike; Marcus, Matthew A.; Shukla, Alpesh Khushalchand; Yi, Tanghong; McDermott, Eamon; Teh, Pei Fen; Srinivasan, Madhavi; Moewes, A.; Cabana, Jordi

doi:10.1038/srep07133

Cited by 56 publications

(69 citation statements)

References 59 publications

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“…Li 2 CO 3 and LiF, do not correspond to the observed EELS [52]. It strengthens the validity of our suggestion that Li 2 O may have delithiated itself instead of reacting with other materials, which was inferred from the electron diffraction experiment.…”

Section: The Unknown Reactions In the Charge Processsupporting

confidence: 75%

Unveiling origin of additional capacity of SnO2 anode in lithium-ion batteries by realistic ex situ TEM analysis

et al. 2016

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Section: The Unknown Reactions In the Charge Processsupporting

confidence: 75%

Unveiling origin of additional capacity of SnO2 anode in lithium-ion batteries by realistic ex situ TEM analysis

et al. 2016

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“…The Co L-edge NEXAFS spectrum further favors this ( Figure S2). The main edge energy value for Ni ions is associated with the 3+ oxidation state, which is characteristic of the NCM811 cathode material and reported by numerous authors [32][33][34]. This oxidation state of Ni ions is also evident from the Ni L-edge NEXAFS spectrum ( Figure S3).…”

Section: Resultssupporting

confidence: 68%

Soft X-ray Absorption Spectroscopic Investigation of Li(Ni0.8Co0.1Mn0.1)O2 Cathode Materials

et al. 2020

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Herein, we report the soft X-ray absorption spectroscopic investigation for Li(Ni 0.8 Co 0.1 Mn 0.1 ) O 2 cathode material during charging and discharging. These measurements were carried out at the Mn L-, Co L-, and Ni L-edges during various stages of charging and discharging. Both the Mn and Co L-edge spectroscopic measurements reflect the invariance in the oxidation states of Mn and Co ions. The Ni L-edge measurements show the modification of the oxidation state of Ni ions during the charging and discharging process. These studies show that e g states are affected dominantly in the case of Ni ions during the charging and discharging process. The O K-edge measurements reflect modulation of metal-oxygen hybridization as envisaged from the area-ratio variation of spectral features corresponding to t 2g and e g states.Nanomaterials 2020, 10, 759 2 of 11 soft XAS measurements can give a complete account of underlying phenomena due to the orbital symmetry states in the oxide cathode material during charging and discharging. To depict these phenomena, the Ni-rich cathode material, Li(Ni 0.8 Co 0.1 Mn 0.1 )O 2 , is selected for the present investigation and denoted as NCM811. NCM811 is a well-known layered oxide cathode material and preferred for Li rechargeable batteries due to its high capacity [19,20]. Thus, this work investigates NCM811 cathode materials during charging and discharging using soft XAS. Experimental DetailsX-ray diffraction (XRD) experiments prior to electrochemical testing of cathode material were performed with the 9B high-resolution powder diffraction (HRPD) beamline of the Pohang accelerator laboratory (PAL) [21]. Pristine cathode material was also investigated using X-ray absorption near-edge spectroscopy (XANES) imaging measurements to reveal the local electronic structure. These measurements at the Mn K-, Co K-, and Ni K-edge were performed with the 7C X-ray nano imaging (XNI) beamline of the PAL. This beamline utilizes zone plate-based transmission X-ray nanoscopy, which is a kind of transmission X-ray microscopy (TXM), for image formation. A zone plate of diameter 150 µm and 40 nm outermost zone width was used for measurements. This arrangement gave a spatial resolution of 40 nm and a field of view (FOV) of around 50 µm. The X-ray absorption images based on TXM were captured at various energies within a 1 eV interval in the range −20 to 80 eV from the main edge energies of each respective element. The XANES spectrum was extracted from these X-ray absorption images [22].Soft XAS measurements of this cathode material at various charging and discharging states were performed with the 10D XAS-KIST beamline of the same laboratory in total electron yield (TEY) mode. The grating with 1100 grooves/mm was used to measure spectra at the Mn L-, Co L-, Ni L-, and O K-edges. The obtained spectra were background-subtracted and normalized with respect to the post-edge height [23]. Results and Discussion

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“…This is due in part to kinetic issues, though theoretical and experimental works have also found evidence of significant thermodynamic barriers to reversibility in displacement and conversion systems. [7][8][9] In addition to chemical irreversibility, conversion materials undergo nanostructuring during the first discharge, whereupon initially micron or sub-micron particles are converted to nanoparticles of M 0 that are 2 nm to 5 nm in diameter in a matrix of disordered Li n X. 10 This study focuses on porous transition metal compounds, which have been extensively studied for surface-based energy storage, especially pseudocapacitors.…”

Section: Introductionmentioning

confidence: 99%

MnO Conversion in Li-Ion Batteries: In Situ Studies and the Role of Mesostructuring

Butala

Danks

Lumley

et al. 2016

ACS Appl. Mater. Interfaces

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Complex manganese oxides have been extensively studied as intercalation Li-ion battery electrodes. The simple oxide MnO has been proposed as a conversion anode material with a theoretical capacity of 756 mAh g −1 for full reduction to the metal.We report the reaction of MnO with Li using in situ X-ray diffraction and find no sign of crystalline products upon either discharge or charge. However, the absence of reflections, paired with electrochemical impedance spectroscopy, suggests disordered discharge products. We also examine composite electrodes with porous particles of MnO as the active component, with pores generated through the reductive heating of Mn 3 O 4 . We compare the behavior of these with more dense MnO powders, including studies of the electrode morphologies pre-and post-cyling. We find differences in the first discharge relevant to the utility of such mesostructuring in conversion reaction materials. Specifically, we find this type of mesostructure, which gives advantage in intercalation and pseudocapacitive storage, does not yield the same benefits for conversion reaction systems.2

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Asymmetric pathways in the electrochemical conversion reaction of NiO as battery electrode with high storage capacity

Cited by 56 publications

References 59 publications

Unveiling origin of additional capacity of SnO2 anode in lithium-ion batteries by realistic ex situ TEM analysis

Unveiling origin of additional capacity of SnO2 anode in lithium-ion batteries by realistic ex situ TEM analysis

Soft X-ray Absorption Spectroscopic Investigation of Li(Ni0.8Co0.1Mn0.1)O2 Cathode Materials

MnO Conversion in Li-Ion Batteries: In Situ Studies and the Role of Mesostructuring

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