Modulating the Spin State to Stabilize the Surface and Bulk Structure for Durable 4.6 V LiCoO₂ Cathodes

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(48)

Published: Aug. 13, 2024

Abstract High‐voltage LiCoO 2 (LCO) attracts great interest due to its high theoretical capacity, however, the aggravated oxygen redox, Co dissolution, and lattice degradation at voltage potentially induce instability of crystal structural cathode–electrolyte interphase, can ultimately lead severe capacity fading. Herein, a design strategy spin modulation is presented stabilize surface bulk structure commercial (C‐LCO). The prepared high‐spin state via field elevates Co─O band gap, suppresses electronic compensation voltage, reduces side reactions reactive dissolved ions with electrolyte, which greatly restrains irreversible phase transition from O3 H1‐3 degeneration interphase. As result, spin‐modulated shows significantly improved electrochemical performances including discharge stable cycling behavior, enhanced rate capability. This work based on modification by apply other layered metal oxide cathodes, providing new avenue for developing high‐energy–density cathodes.

Language: Английский

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Iridium(III) Carbene Phosphors with Fast Radiative Transitions for Blue Organic Light Emitting Diodes and Hyperphosphorescence

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 3, 2024

Abstract It is envisioned that the efficient and stable blue OLED phosphors can be synthesized using Ir(III) complexes with electron‐deficient carbene cyclometalates. Therefore, three facially coordinated f ‐ct7a‐ c bearing isomeric purinylidene chelates are obtained. They possess three, two, one 4‐ t ‐butylphenyl cyclometalate together same number of N‐phenyl appendage on fragments, exhibit photoluminescence centered ( λ max ) at 452‒461 nm, fast radiative rate constants k r 7.5–11.3 × 10 5 s ‒1 , high quantum yield (PLQY) up to 80% in degassed toluene RT. Representative based ‐ct7c gives maximum external efficiency (EQE 26.6%, CIE x y 0.16, 0.15, low roll‐off EQE 22.3% 1000 cd m ‒2 . Furthermore, they utilized sensitize a deep multiple resonance thermally activated delay fluorescence emitter (MR‐TADF), i.e., ‐DABNA. The corresponding hyper‐OLED device alternative ‐ct7b realizes an 36.1%, 0.14, 0.09, full width half (FWHM) 26.5 nm. To understanding, this first report concurrent achieving both small value for Ir(III)‐based phosphors.

Language: Английский

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Suppressed Electrolyte Decomposition Behavior to Improve Cycling Performance of LiCoO₂ under 4.6 V through the Regulation of Interfacial Adsorption Forces

Advanced Science, Journal Year: 2024, Volume and Issue: 11(25)

Published: April 23, 2024

Abstract Alleviating the decomposition of electrolyte is great significance to improving cycle stability cathodes, especially for LiCoO 2 (LCO), its volumetric energy density can be effectively promoted by increasing charge cutoff voltage 4.6 V, thereby supporting large‐scale application clean energy. However, rapid under V conditions not only loses transport carrier lithium ion, but also produces HF and insulators that destroy interface LCO increase impedance. In this work, suppressed changing adsorption force between EC. Density functional theory illustrates coated with lower electronegativity elements has a weaker electrolyte, LCO@Mg EC (0.49 eV) than LCO@Ti (0.73 eV). Meanwhile, based on results time flight secondary ion mass spectrometry, conductivity‐atomic microscopy, in situ differential electrochemical soft X‐ray absorption spectroscopy, nuclear magnetic resonance, as increases, decomposes more seriously. This work provides new perspective interaction cathode further improves understanding decomposition.

Language: Английский

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Direct Regeneration of Spent Lithium-Ion Battery Cathodes: From Theoretical Study to Production Practice

Nano-Micro Letters, Journal Year: 2024, Volume and Issue: 16(1)

Published: May 31, 2024

Abstract Direct regeneration method has been widely concerned by researchers in the field of battery recycling because its advantages situ regeneration, short process and less pollutant emission. In this review, we firstly analyze primary causes for failure three representative cathodes (lithium iron phosphate, layered lithium transition metal oxide cobalt oxide), targeting at illustrating their underlying mechanism applicability. Efficient stripping material from collector to obtain pure cathode become a first challenge recycling, which report several pretreatment methods currently available subsequent processes. We review discuss emphatically research progress five direct methods, including solid-state sintering, hydrothermal, eutectic molten salt, electrochemical chemical lithiation methods. Finally, application technology production practice is introduced, problems exposed early stage industrialization are revealed, prospect future large-scale commercial proposed. It hoped that will give readers comprehensive basic understanding used lithium-ion batteries promote industrial technology.

Language: Английский

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Revealing Gliding-Induced Structural Distortion in High-Nickel Layered Oxide Cathodes for Lithium-Ion Batteries

ACS Nano, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 25, 2024

After charging to a high state-of-charge (SoC), layered oxide cathodes exhibit capacities but suffer from gliding-induced structural distortions caused by deep Li depletion within alkali metal (AM) layers, especially for high-nickel candidates. In this study, we identify the essential structure of detrimental H3 phase formed at SoC be an intergrowth characterized random sequences O3 and O1 slabs, where slabs represent Li-rich layers denote Li-depleted (or empty) that glide slabs. Moreover, adopt two doping strategies targeting different sites eliminate formation Li-vacant First, introduce direct transition (TM) pillars between TMO

Language: Английский

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Progress and perspective of doping strategies for lithium cobalt oxide materials in lithium-ion batteries

Energy storage materials, Journal Year: 2024, Volume and Issue: 71, P. 103666 - 103666

Published: July 31, 2024

Language: Английский

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Microscopic electrochemical–mechanical coupling in layered cathodes under high-voltage and fast-charging conditions

EES batteries., Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

This review examines electrochemical-mechanical coupling in layered oxide cathodes, linking delithiation-induced electrochemical degradation to anisotropic mechanical strain, while summarizing recent advances cathode material modifications.

Language: Английский

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In‐device Battery Failure Analysis

Advanced Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

Lithium-ion batteries are indispensable power sources for a wide range of modern electronic devices. However, battery lifespan remains critical limitation, directly affecting the sustainability and user experience. Conventional failure analysis in controlled lab settings may not capture complex interactions environmental factors encountered real-world, in-device operating conditions. This study analyzes commercial wireless earbud as model system within their intended usage context. Through multiscale multimodal characterizations, degradations from material level to device correlated, elucidating pattern that is closely tied specific configuration The findings indicate ultimate mode determined by interplay materials, cell structural design, microenvironment, such temperature gradients fluctuations. holistic, perspective on influences provides insights integration enhancing reliability electronics.

Language: Английский

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Stabilizing 4.6 V LiCoO₂ via Surface‐to‐Bulk Titanium Modification

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 3, 2024

Abstract Elevating the charging cut‐off voltage is an effective strategy to increase energy density of LiCoO 2 . However, unstable interfacial structures and unfavorable phase transitions in bulk are inevitably triggered during deep de‐lithiation at high voltage. Herein, integrated surface‐to‐bulk Ti‐modification applied , enabling uniform Li TiO 3 coating on surface gradient Ti‐doping toward structural bulk. The resultant Ti‐modified (T‐LCO) electrode can be stably cycled up 4.6 V, providing a high‐rate capability 137 mAh g −1 5C long‐life stability with 80.5% capacity retention after 400 cycles 1C, far outperforming unmodified only 50.7% retention. In situ X‐ray diffraction characterization functional theory calculation reveal that synergistic modification T‐LCO enhances + diffusion, facilitates construction high‐quality cathode/electrolyte interphase, reduces transition from O3 H1‐3 Co3d/O2p band overlap, restrains layer‐to‐spinel distortion, thus improving V. This work presents “two birds one step” enhance cycling achievable high‐voltage for developing lithium‐ion batteries.

Language: Английский

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Enhancing the Structural Stability of LiCoO₂ at Elevated Voltage via High-Valence Sb Doping

ACS Applied Energy Materials, Journal Year: 2024, Volume and Issue: 7(9), P. 4207 - 4215

Published: April 29, 2024

Elevating the charging cutoff voltage of lithium cobalt oxide (LiCoO2) batteries to 4.6 V (vs Li/Li+) enables attainment an impressive specific capacity; however, this advancement is hampered by severe structural degradation above 4.45 attributed unfavorable phase transitions and occurrence undesirable side reactions. Herein, we introduce high-valence Sb5+ into LiCoO2, suppressing O3 H1–3 transition thereby enhancing stability LiCoO2. The stable structure not only formation a more cathode-electrolyte interphase film on surface LiCoO2 but also suppresses dissolution Co, reducing As result, Sb-doped serving as anode, exhibited remarkable capacity 169.2 mAh g–1 at current density 1C, with durable retention 83.2% after 100 cycles. This study offers modulation strategy for further high-voltage cathodes.

Language: Английский

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