Abstract Ni-rich LiNi 0.8 Co 0.1 Mn O 2 layered oxide cathodes have been highlighted for large-scale energy applications due to their high density. Although its specific capacity is enhanced at higher voltages as Ni ratio increases, structural degradation phase transformations and lattice distortions during cycling becomes severe. For these reasons, we focused on the origins of crack generation from in using multiscale approaches, first-principles meso-scale phase-field model. Atomic-scale...

Abstract The practical application of lithium‐sulfur (Li‐S) batteries remains remote because rapid capacity fade caused by the low conductivity sulfur, dissolution intermediate lithium polysulfides, severe volumetric expansion, and slow redox kinetics polysulfide intermediates. Here, to address these obstacles, a new sulfiphilic highly conductive honeycomb‐like spherical cathode host constructed from hollow metallic polar Co 9 S 8 tubes is designed. can effectively bind polysulfides for...

A double-hierarchical sulfur host has been synthesized in which hierarchical carbon spheres, constructed from building blocks of hollow nanobubbles used for loading sulfur, are sealed by a polar MoS₂ coating that is composed ultrathin nanosheets (MoS₂@HCS composite).

Our observations indicate that thermodynamically stable and kinetically movable intermediate tetrahedral states of Mn are the main origin migration, leading to phase transformation Li₂MnO₃.

Solid-state electrolytes based on ionic liquids and a gelling matrix are promising for rechargeable lithium-ion batteries due to their safety under diverse operating conditions, favorable electrochemical thermal properties, wide processing compatibility. However, gel also suffer from low mechanical moduli, which imply poor structural integrity thus an enhanced probability of electrical shorting, particularly conditions that lithium dendrite growth. Here, we realize high-modulus,...

By preventing electrical contact between anode and cathode electrodes while promoting ionic transport, separators are critical components in the safe operation of rechargeable battery technologies. However, traditional polymer-based have limited thermal stability, which has contributed to catastrophic runaway failure modes that conspicuously plagued lithium-ion batteries. Here, we describe development phase-inversion composite based on carbon-coated hexagonal boron nitride (hBN) nanosheets...

As a promising Li⁺source for lithium-ion capacitors, electrochemical and structural stabilities of Li₆CoO₄are investigated.

A synergistic approach for advanced cathode materials is proposed. Sodium manganese oxide with a layered-tunnel hybrid structure was designed, synthesized, and subsequently investigated. The provides fast Na ion diffusivity high structural stability thanks to the tunnel phase, enabling rate capability greatly improved cycling compared that of pure P2 layered phase while retaining specific capacity phase. provided decent discharge 133.4 mAh g-1 even at 8 C, which exceeds reported best...

Abstract Irreversible phase transformation of layered structure into spinel is considered detrimental for most the cathode materials. Here we report that this presumably irreversible can be rendered to reversible in sodium birnessite (Na x MnO 2 · y H O) as a basic structural unit. This contains crystal water, which facilitates formation metastable spinel-like and unusual reversal back structure. The mechanism reversibility was elucidated by combined soft hard X-ray absorption spectroscopy...

Abstract To achieve the high energy densities demanded by emerging technologies, lithium battery electrodes need to approach volumetric and specific capacity limits of their electrochemically active constituents, which requires minimization inactive components electrode. However, a reduction in percentage conductive additives charge transport within electrode, results compromised electrochemical performance. Here, an electrode design that achieves efficient electron lithium‐ion kinetics at...

Through first-principles calculations and experimental observations, we first present the correlation between Ni Mn ratio redox behaviors of layered NCM cathodes. The equilibrium potentials based on reactions Ni2+/Ni3+ are highly dependent (NCM523 NCM721: ∼3.7 3.5 V) because a donor electron, in eg band, transferred from to owing their crystal field splitting (CFS) with different electronegativities, leading oxidation states Ni2+-like Mn4+. Considering electronic (Mn) CFS electronegativity...

Abstract A combined experimental and computational study of an oxygen‐deficient Li 2 MnO 3− δ ( ≈0.071) cathode for understanding the role effects oxygen vacancies on phase transformation electrochemical activity in Li‐ion batteries is presented. The exhibits improved reactivity toward + ions without significant loss structural stability. oxidation O during ion extraction can be suppressed by enhanced redox reaction Mn this material. Furthermore, inevitable 3 impeded increased kinetic...

2D materials have shown great promise to advance next-generation lithium-ion battery technology. Specifically, tin-based chalcogenides attracted widespread attention because lithium insertion can introduce phase transformations via three types of reactions-intercalation, conversion, and alloying-but the corresponding structural changes throughout these processes, whether they are reversible, not fully understood. Here, first real-time atomic-scale observation reversible is reported during...

Abstract Liquid‐phase exfoliation of layered solids holds promise for the scalable production 2D nanosheets. When combined with suitable solvents and stabilizing polymers, rheology resulting nanosheet dispersions can be tuned a variety additive manufacturing methods. While significant progress is made in development electrically conductive inks, minimal effort applied to ion‐conductive inks despite their central role energy storage applications. Here, formulation viscosity‐tunable hexagonal...

Abstract Layer‐structured oxide cathodes have a lot of phases, which can be varied depending on Na ion contents and finally determine their electrochemical properties. Therefore, the off‐stoichiometry layer‐structured oxides with ions may differentiate not only capacities but also cyclic stabilities, kinetics, so on, highlighting importance content. However, 2 CO 3 tends to irreversibly formed surface by making use lost from lattice. Thereby, O3 phase stoichiometric content changes into...

Through a gelation-solvothermal method without heteroadditives, Cu-Sn-S composites self-assemble to form nanotubes, sub-nanotubes, and nanoparticles. The nanotubes with Cu3-4SnS4 core Cu2SnS3 shell can tolerate long cycles of expansion/contraction upon lithiation/delithiation, retaining charge capacity 774 mAh g-1 after 200 high initial Coulombic efficiency 82.5%. importance the Cu component for mitigation volume expansion structural evolution lithiation is informed by density functional...

In lithium-ion batteries (LIBs) comprising spinel cathode materials, the dissolution of transition metals (TMs) in cathodes causes severe cyclic degradation. We investigate origin and mechanism surface TM high-voltage oxide (LiNi0.5 Mn1.5 O4 ) nanoparticles to find a practical method for its mitigation. Atomic structures LiNi0.5 surfaces are developed, electronic investigated by first-principles calculations. The results indicate that titanium is promising dopant forming more stable...

Through a simple gelation–solvothermal method with graphene oxide as the additive, Cu4SnS4-rich composite of nanoparticles and nanotubes is synthesized applied for thin flexible Li-metal batteries. Unlike Cu2SnS3-rich electrode, electrode cycles stably an enhanced conversion capacity ∼416 mAh g–1 (∼52% total capacity) after 200 cycles. The lithiation/delithiation mechanisms Cu–Sn–S electrodes voltage ranges alloying reactions are informed by in situ X-ray diffraction tests. process three...

Abstract Critical degradation mechanism of many cathode materials for Li‐ion batteries is closely related to phase transformations at the surface/interface. Li 2 MnO 3 in x ⋅(1− ) LiMO (M=Ni, Co, Mn) provides high capacity, but known degrade during cycling through transformation and O evolution. To resolve such problems, it critical develop a fundamental understanding underlying mechanism. Using first‐principles calculations, we identified surface delithiation potential (<4.5 V vs. Li/Li...

A fundamental understanding of anomalous redox mechanisms in hexacyanometallate compounds, compared with conventional NaMO2 systems (M: transition metals), is presented based on first-principles calculations and experimental validations. From theoretical calculations, we identified low-spin high-spin states Fe ions coordinated by the cyanide group (-CN) same oxidation state (Fe2+) Na2Fe2(CN)6. Considering site dependency d electronic spin configurations crystal field theory (CFT) metals...

We report the introduction of p-type conductivity in high-Mn, Li-rich oxides (HMLOs) by Cu doping to improve intrinsic electronic conduction. The study is based on experimental observations and a fundamental understanding through first-principles structure analysis. Although Cu-doped HMLO (CuHMLO) has crystal identical original HMLO, electrochemical performance CuHMLO superior terms specific energy power characteristics. Specifically, exhibits larger capacity with enhanced rate capability,...

A combined study involving experiments and multiscale computational approaches is conducted to propose a theoretical solution for the suppression of Jahn-Teller distortion which causes severe cyclic degradation. As-synthesized pristine Al-doped Mn spinel compounds are focus understand mechanism degradation in terms distortion, electrochemical performance sample shows enhanced compared with that one. Considering electronic structures two systems using first-principles calculations, suffers...