Probing thermally-induced structural evolution during the synthesis of layered Li-, Na-, or K-containing 3d transition-metal oxides

Hua, Weibo; Yang, Xiaoxia; Casati, Nicola; Liu, Laijun; Wang, Suning; Baran, Volodymyr; Knapp, Michael; Ehrenberg, Helmut; Indris, Sylvio

doi:10.1016/j.esci.2022.02.007

Cited by 53 publications

(35 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally, the layered transition metal oxides, including NCM and LMLOs, are synthesized by using a co-precipitation method followed by a high-temperature solid-state reaction. [23][24][25][26][27] The nano-sized primary particles tend to agglomerate to form micron-sized spherical secondary particles during the co-precipitation process, concomitant with the formation of voids inside the secondary particles. [28,29] The agglomerates provide a reduced diffusion length for Li-ions within their primary particles and an increased number of pores, which facilitate the transport of Li-ions and enhance the rate capability of cathode materials.…”

Section: Introductionmentioning

confidence: 99%

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ Cathodes

Yang

Wang

Han

et al. 2022

Small

Self Cite

View full text Add to dashboard Cite

electric vehicles (HEVs), next-generation lithium-ion batteries (LIBs) that utilize high-energy cathode materials are crucially needed. [1][2][3] Among various types of cathode materials, Li-and Mn-rich layered oxides (LMLOs) are regarded as one of the most promising cathode candidates owing to their high capacity (≥250 mAh g −1 ) and low cost. [4][5][6][7] The high capacity of LMLOs is widely believed to originate predominantly from the reversible cationic and anionic redox activities, [8][9][10] which remarkably overcome the capacity limitations of conventional cathode materials (<200 mAh g −1 ) like olivine LiFePO 4 (space group: Pnma), [11,12] spinel LiMn 2 O 4 (Fd3m), [13,14] and layered Li[Ni,Co,Mn]O 2 (NCM, square brackets represent transition metal ions located on octahedral positions, R3m) [15][16][17][18] because of the sole transition metal (TM) redox activity in these cathodes. Nevertheless, LMLOs always undergo a severe voltage decay upon cycling, [19,20] which seriously hinders the practical application of LMLOs. Over the last two decades, a series of attempts have been made to reveal the underlying structural degradation mechanism and mitigate the voltage decay during extended cycling.Lithium-and manganese-rich layered oxides (LMLOs, ≥ 250 mAh g −1 ) with polycrystalline morphology always suffer from severe voltage decay upon cycling because of the anisotropic lattice strain and oxygen release induced chemo-mechanical breakdown. Herein, a Co-free single-crystalline LMLO, that is, Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 (LLNMO-SC), is prepared via a Li + /Na + ionexchange reaction. In situ synchrotron-based X-ray diffraction (sXRD) results demonstrate that relatively small changes in lattice parameters and reduced average micro-strain are observed in LLNMO-SC compared to its polycrystalline counterpart (LLNMO-PC) during the charge-discharge process. Specifically, the as-synthesized LLNMO-SC exhibits a unit cell volume change as low as 1.1% during electrochemical cycling. Such low strain characteristics ensure a stable framework for Li-ion insertion/extraction, which considerably enhances the structural stability of LLNMO during long-term cycling. Due to these peculiar benefits, the average discharge voltage of LLNMO-SC decreases by only ≈0.2 V after 100 cycles at 28 mA g −1 between 2.0 and 4.8 V, which is much lower than that of LLNMO-PC (≈0.5 V). Such a single-crystalline strategy offers a promising solution to constructing stable high-energy lithium-ion batteries (LIBs).

show abstract

Section: Introductionmentioning

confidence: 99%

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ Cathodes

Yang

Wang

Han

et al. 2022

Small

Self Cite

View full text Add to dashboard Cite

show abstract

“…The layered structure P2-type KMO materials were synthesized via a facile high-temperature solid-state reaction. 32 Rietveld-refined X-ray diffraction (XRD) was used to confirm the structure and phase impurity of the as-prepared KMO as shown in Fig. 1a.…”

Section: Resultsmentioning

confidence: 99%

A high-performance Na-storage cathode enabled by layered P2-type K_xMnO₂ with enlarged interlayer spacing and fast diffusion channels for sodium-ion batteries

et al. 2022

View full text Add to dashboard Cite

show abstract

“…In a mixed system of an anionic surfactant and a nonionic surfactant, on the one hand, the existence of EO groups can reduce the electrostatic repulsion between anionic head groups, and the surfactants are closely arranged at the interface. On the other hand, when multivalent counterions exist, EO groups can hinder the transition of the surfactant at the interface from monolayer to multilayer, and when the concentration of EO groups remains unchanged, there is a greater concentration of multivalent counterions and more adsorption layers. − Therefore, we believe that in the O/W emulsion, due to the low concentration of Fe(III) species compared with the former, EO groups play a major role in hindering the formation of a multilayer structure of the surfactant at the interface, resulting in a low strength of the interfacial film. Therefore, compared with the O/W emulsion without EO groups, its stability is poor.…”

Section: Resultsmentioning

confidence: 99%

Effect of Fe(III) Species on the Stability of a Water-Model Oil Emulsion with an Anionic Sulfonate Surfactant as an Emulsifier

Zheng

Wang

et al. 2022

ACS Omega

View full text Add to dashboard Cite

The stability of an emulsion has an important effect on enhancing oil recovery. However, the effect of ions with different valences on the stability of the emulsion emulsified by an ionic surfactant is not fully understood. In this study, the effects of Fe(III) species on the stability, microscopic morphology of droplets, interfacial properties, and rheological properties of water-model oil emulsions emulsified by sodium dodecyl benzenesulfonate (SDBS) were explored. The effect of Fe(III) species on the stability of a W/O crude oil emulsion was also explored. The stability experiment results show that the addition of the Fe(III) species impairs the stability of the model oil-in-water (O/W) emulsion, in which the O/W model oil emulsion is inverted to a water-in-model oil (W/O) emulsion at ∼99 ppm. With the increase of Fe(III) species concentration, stable W/O model oil and W/O crude oil emulsions are obtained. The rheological results indicated that the existence of the Fe(III) species has a remarkable effect on the viscosity and viscoelastic behaviors of the water-model oil emulsion. The calculation results based on Derjaguin−Landau−Verwey−Overbeek (DLVO) theory are in accord with the stability experiment results. Furthermore, the addition of EO groups makes the phase inversion point appear at a higher Fe(III) species concentration, forming a more stable W/O model oil emulsion and a more unstable O/W model oil emulsion. The experimental results are helpful to comprehensively understand the effect of Fe(III) species on the stability of an emulsion emulsified by an anionic sulfonate surfactant, which can help to enhance the oil recovery.

show abstract

Probing thermally-induced structural evolution during the synthesis of layered Li-, Na-, or K-containing 3d transition-metal oxides

Cited by 53 publications

References 47 publications

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ Cathodes

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ Cathodes

A high-performance Na-storage cathode enabled by layered P2-type K_xMnO₂ with enlarged interlayer spacing and fast diffusion channels for sodium-ion batteries

Effect of Fe(III) Species on the Stability of a Water-Model Oil Emulsion with an Anionic Sulfonate Surfactant as an Emulsifier

Contact Info

Product

Resources

About

Probing thermally-induced structural evolution during the synthesis of layered Li-, Na-, or K-containing 3d transition-metal oxides

Cited by 53 publications

References 47 publications

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li0.2Ni0.2Mn0.6]O2 Cathodes

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li0.2Ni0.2Mn0.6]O2 Cathodes

A high-performance Na-storage cathode enabled by layered P2-type KxMnO2 with enlarged interlayer spacing and fast diffusion channels for sodium-ion batteries

Effect of Fe(III) Species on the Stability of a Water-Model Oil Emulsion with an Anionic Sulfonate Surfactant as an Emulsifier

Contact Info

Product

Resources

About

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ Cathodes

Structural Origin of Suppressed Voltage Decay in Single‐Crystalline Li‐Rich Layered Li[Li_0.2Ni_0.2Mn_0.6]O₂ Cathodes

A high-performance Na-storage cathode enabled by layered P2-type K_xMnO₂ with enlarged interlayer spacing and fast diffusion channels for sodium-ion batteries