In Situ Constructing Ultrastable Mechanical Integrity of Single‐Crystalline LiNi_0.9Co_0.05Mn_0.05O₂ Cathode by Interior and Exterior Decoration Strategy

Small, Год журнала: 2023, Номер 20(5)

Опубликована: Сен. 27, 2023

Abstract Planar gliding along with anisotropic lattice strain of single‐crystalline nickel‐rich cathodes (SCNRC) at highly delithiated states will induce severe delamination cracking that seriously deteriorates LIBs’ cyclability. To address these issues, a novel lattice‐matched MgTiO 3 (MTO) layer, which exhibits same structure as Ni‐rich cathodes, is rationally constructed on LiNi 0.9 Co 0.05 Mn O 2 (SC90) for ultrastable mechanical integrity. Intensive in/ex situ characterizations combined theoretical calculations and finite element analysis suggest the uniform MTO coating layer prevents direct contact between SC90 organic electrolytes enables rapid Li‐ion diffusion depressed Li‐deficiency, thereby stabilizing interfacial accommodating stress SC90. More importantly, superstructure simultaneously formed in SC90, can effectively alleviate changes decrease cation mobility during successive high‐voltage de/intercalation processes. Therefore, as‐acquired MTO‐modified cathode displays desirable capacity retention stability. When paired commercial graphite anodes, pouch‐type cells deliver high 175.2 mAh g −1 89.8% after 500 cycles. This lattice‐matching strategy demonstrate effective pathway to maintain structural stability electrode materials, be pioneering breakthrough commercialization cathodes.

Язык: Английский

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Revealing the Nanoscopic Corrosive Degradation Mechanism of Nickel-Rich Layered Oxide Cathodes at Low State-of-Charge Levels: Corrosion Cracking and Pitting

ACS Nano, Год журнала: 2024, Номер 18(15), С. 10566 - 10581

Опубликована: Апрель 1, 2024

Ni-rich layered oxides have received significant attention as promising cathode materials for Li-ion batteries due to their high reversible capacity. However, intergranular and intragranular cracks form at state-of-charge (SOC) levels exceeding 4.2 V (vs. Li/Li+), representing a prominent failure mechanism of oxides. The nanoscale crack formation SOC is attributed volume change resulting from phase transition between the H2 H3 phases. Herein, in contrast electrochemical levels, another chemical pit on directly evidenced fully lithiated (low levels). This associated with stress corrosion cracking, driven by elevated temperatures. nanoscopic behavior during aging temperatures investigated using high-resolution transmission electron microscopy, revealing that microcracks can develop through two distinct mechanisms: cycling corrosion. Notably, occur even discharged state levels), whereas are observed only levels. finding provides comprehensive understanding complex mechanisms an opportunity improve performance.

Язык: Английский

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Ni-rich cathode evolution: exploring electrochemical dynamics and strategic modifications to combat degradation

Energy storage materials, Год журнала: 2024, Номер 69, С. 103440 - 103440

Опубликована: Апрель 30, 2024

Язык: Английский

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Invoking Interfacial Engineering Boosts Structural Stability Empowering Exceptional Cyclability of Ni‐Rich Cathode

Advanced Materials, Год журнала: 2024, Номер 36(32)

Опубликована: Июнь 11, 2024

Abstract The cycling stability of LiNi 0.8 Co 0.1 Mn O 2 under high voltages is hindered by the occurrence hybrid anion‐ and cation‐redox processes, leading to oxygen escape uncontrolled phase collapse. In this study, an interfacial engineering strategy involving a straightforward mechanical ball milling low‐temperature calcination, employing Se‐doped FeSe &Fe 3 ‐modified approach proposed design stable Ni‐rich cathode. Se 2− are selectively adsorbed within vacancies form ─ TM bond, effectively stabilizing lattice oxygen, preventing structural distortion. Simultaneously, Se‐NCM811//FeSe //Fe self‐assembled electric field activated, improving charge transfer coupling. Furthermore, accelerates Li + diffusion reacts with Fe SeO . coating mitigates hydrofluoric acid erosion acts as electrostatic shield layer, limiting outward migration anions. Impressively, modified materials exhibit significantly improved electrochemical performance, capacity retention 79.7% after 500 cycles at 1C 4.5 V. it provides extraordinary 94.6% in 3–4.25 V 550 pouch‐type full battery. This dual‐modification demonstrates its feasibility opens new perspective for development lithium‐ion batteries operating voltages.

Язык: Английский

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Surface Atomic Rearrangement with High Cation Ordering for Ultra‐Stable Single‐Crystal Ni‐Rich Co‐Less Cathode Materials

Advanced Functional Materials, Год журнала: 2024, Номер unknown

Опубликована: Авг. 5, 2024

Abstract It is crucial to minimize cobalt content in Ni‐rich layered single‐crystal cathodes due their high price and limited availability, yet it will inevitably lead cation disordering, capacity degradation, thermal issues. Herein, overcome the intrinsic trade‐off between performance composition of Co‐less cathodes, a precursor engineering strategy with an epitaxially grown enrichment on surface innovatively proposed. In contrast traditional coating modifications random orientation rigid surface‐bulk boundary, enriched layer undergoes rapid interdiffusion internal Ni 3+ during optimized sintering process. This eliminates promoting uniform distribution synergistically addressing Li/Ni intermixing. Moreover, enhanced Li + diffusion obtained, thereby suppressing concentration gradient intragranular cracks generation. Consequently, modified LiNi 0.7 Co 0.07 Mn 0.23 O 2 exhibits impressive cycling stability increased retention both coin‐type half‐cells pouch‐type full‐cells (91% after 1000 cycles), even under harsh condition high‐temperature, surpassing majority previously reported cathodes. work opens new avenues toward low cost, energy density, stability, long cyclic life for sheds light large‐scale commercial production.

Язык: Английский

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