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High‐voltage spinel‐type structured LiNi0.5Mn1.5O4 (LNMO) shows promise as a next‐generation high‐energy‐density lithium‐ion battery cathode material, however, capacity decay on extended cycling hinders its widespread adoption, underscoring an urgent need for further development. In this work, we introduce Zn at octahedral 16c crystal sites in LNMO with Fd3‾ ${\bar{3}}$ m space group to improve rate capability and reduce the rapid capacity decay otherwise experienced during extended cycling. The current work resolves the detailed influence of isolated modification at octahedral 16c crystal sites, unveiling the mechanism for these performance improvements. We show that occupation of Zn at previously empty 16c sites prevents the migration of Ni/Mn to adjacent 16c sites, eliminating transformation to a rock‐salt type structured Ni0.25Mn0.75O2 phase above 4.8 V, preventing structure degradation and suppressing voltage polarization. This study provides insights into the fundamental structure‐function relationship of the LNMO battery cathode, pointing to pathways for the crystal structure engineering of materials with superior performance. [ABSTRACT FROM AUTHOR]

Manganese‐based layered oxides are currently of significant interest as cathode materials for sodium‐ion batteries due to their low toxicity and high specific capacity. However, the practical applications are impeded by sluggish intrinsic Na+ migration and poor structure stability as a result of Jahn–Teller distortion and complicated phase transition. In this study, a high‐entropy strategy is proposed to enhance the high‐voltage capacity and cycling stability. The designed P2‐Na0.67Mn0.6Cu0.08Ni0.09Fe0.18Ti0.05O2 achieves a deeply desodiation and delivers charging capacity of 158.1 mAh g−1 corresponding to 0.61 Na with a high initial Coulombic efficiency of 98.2 %. The charge compensation is attributed to the cationic and anionic redox reactions conjunctively. Moreover, the crystal structure is effectively stabilized, leading to a slight variation of lattice parameters. This research carries implications for the expedited development of low‐cost, high‐energy‐density cathode materials for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

In this work, 2D ferromagnetic M3GeTe2 (MGT, M = Ni/Fe) nanosheets with rich atomic Te vacancies (2D‐MGTv) are demonstrated as efficient OER electrocatalyst via a general mechanical exfoliation strategy. X‐ray absorption spectra (XAS) and scanning transmission electron microscope (STEM) results validate the dominant presence of metal‐O moieties and rich Te vacancies, respectively. The formed Te vacancies are active for the adsorption of OH* and O* species while the metal‐O moieties promote the O* and OOH* adsorption, contributing synergistically to the faster oxygen evolution kinetics. Consequently, 2D‐Ni3GeTe2v exhibits superior OER activity with only 370 mV overpotential to reach the current density of 100 mA cm−2 and turnover frequency (TOF) value of 101.6 s−1 at the overpotential of 200 mV in alkaline media. Furthermore, a 2D‐Ni3GeTe2v‐based anion‐exchange membrane (AEM) water electrolysis cell (1 cm2) delivers a current density of 1.02 and 1.32 A cm−2 at the voltage of 3 V feeding with 0.1 and 1 m KOH solution, respectively. The demonstrated metal‐O coordination with abundant atomic vacancies for ferromagnetic M3GeTe2 and the easily extended preparation strategy would enlighten the rational design and fabrication of other ferromagnetic materials for wider electrocatalytic applications. [ABSTRACT FROM AUTHOR]

Over recent decades, rapid advancements in energy technology have transformed human life. Lithium‐ion batteries (LIBs) have played a pivotal role nevertheless concerns about limited lithium resources and price fluctuations underscore the need for sustainability. Sodium‐ion batteries (SIBs), operating on principles akin to LIBs, have emerged as promising candidates for rechargeable batteries in the next generation of energy storage systems, primarily due to their cost‐effectiveness and sustainable attributes. Analogous to LIBs, the cathode in SIBs assumes a critical role in dictating the electrochemical performance of the battery. Therefore, the research and development of cathode materials for SIBs take on paramount significance. O3‐type SIB cathodes, inspired by the successful O3‐type LIB cathodes (e. g., LiCoO2 and NMC variants), hold promise for commercial applications. This comprehensive overview offers an in‐depth exploration of various unary‐metal oxide cathode materials characterized by an O3‐layered structure. Subsequently, nickel (Ni), manganese (Mn), and Ni/Mn‐based O3 cathode materials are conducted a comprehensive study, assessing the effects of element substitution and doping on capacity, phase transitions, and cycle life. In light of the current challenges, advancing SIB cathode materials of future directions will propose, addressing key considerations in the pursuit of enhanced performance and sustainable energy storage solutions. [ABSTRACT FROM AUTHOR]

Lattice‐oxygen redox in layered metal oxide cathodes offers a promising way to exploit high‐energy density sodium‐ion batteries. However, oxidation and reduction of lattice‐oxygen are always asymmetric, showing poor reversibility upon charging and discharging due to the activated oxygen loss and subsequent structural rearrangement. Here, a layered Na0.7[Li0.2Mn0.7Co0.1]O2 (NLMCO) is developed by balancing lattice‐oxygen activity and reversibility, which can deliver a record energy density of 729.7 Wh kg−1, further exceeding the state‐of‐the‐art Na0.75[Li0.25Mn0.75]O2 (NLMO, 638.4 Wh kg−1). In light of electron paramagnetic resonance spectroscopy, in situ differential electrochemical mass spectroscopy, and electrochemical testing results, the highly activated lattice‐oxygen is effectively stabilized in NLMCO without oxygen molecule release while obvious oxygen release is detected in the highly activated NLMO. Benefiting from the enhanced transition metal‐oxygen covalency and reduced band energy gap, the NLMCO electrode demonstrates simultaneously high lattice‐oxygen activity and reversibility, thus resulting in excellent rate and cycling performance, as well as ultra‐high energy density. The findings highlight the critical association of energy density and lattice‐oxygen redox reversibility, which will inspire more interest in anionic redox‐based high‐energy batteries. [ABSTRACT FROM AUTHOR]

The search for viable carbon‐neutral sources of renewable energy is one of the most critical challenges in science today. The chemical community is committed to seeking efficient, inexpensive, and sustainable electrocatalysts that can exploit the energy produced by sustainable energy resources. Here, an ethanol organocatalyst, which is green and cheap, that can efficiently catalyze the oxidation of Li2S in the electrochemical reactions of Li2S cathodes is identified. This study demonstrates that a multitude of small molecular organocatalysts will offer electrochemists an elegant tool for accelerating electrochemical reactions with otherwise unattainable efficiency and precision. This concept refashions electrochemical domains and has broad implications for the design of "green" and sustainable chemistry cycles. [ABSTRACT FROM AUTHOR]