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Rechargeable sodium-ion batteries (SIBs) have emerged as an advanced electrochemical energy storage technology with potential to alleviate the dependence on lithium resources. Similar to Li-ion batteries, the cathode materials play a decisive role in the cost and energy output of SIBs. Among various cathode materials, Na layered transition-metal (TM) oxides have become an appealing choice owing to their facile synthesis, high Na storage capacity/voltage that are suitable for use in high-energy SIBs, and high adaptivity to the large-scale manufacture of Li layered oxide analogues. However, going from the lab to the market, the practical use of Na layered oxide cathodes is limited by the ambiguous understanding of the fundamental structure-performance correlation of cathode materials and lack of customized material design strategies to meet the diverse demands in practical storage applications. In this review, we attempt to clarify the fundamental misunderstandings by elaborating the correlations between the electron configuration of the critical capacity-contributing elements (e.g., TM cations and oxygen anion) in oxides and their influence on the Na (de)intercalation (electro)chemistry and storage properties of the cathode. Subsequently, we discuss the issues that hinder the practical use of layered oxide cathodes, their origins and the corresponding strategies to address their issues and accelerate the target-oriented research and development of cathode materials. Finally, we discuss several new Na layered cathode materials that show prospects for next-generation SIBs, including layered oxides with anion redox and high entropy and highlight the use of layered oxides as cathodes for solid-state SIBs with higher energy and safety. In summary, we aim to offer insights into the rational design of high-performance Na layered oxide cathode materials towards the practical realization of sustainable electrochemical energy storage at a low cost. [ABSTRACT FROM AUTHOR]

Solid‐state lithium‐sulfur batteries have shown prospects as safe, high‐energy electrochemical storage technology for powering regional electrified transportation. Owing to limited ion mobility in crystalline polymer electrolytes, the battery is incapable of operating at subzero temperature. Addition of liquid plasticizer into the polymer electrolyte improves the Li‐ion conductivity yet sacrifices the mechanical strength and interfacial stability with both electrodes. In this work, we showed that by introducing a spherical hyperbranched solid polymer plasticizer into a Li+‐conductive linear polymer matrix, an integrated dynamic cross‐linked polymer network was built to maintain fully amorphous in a wide temperature range down to subzero. A quasi‐solid polymer electrolyte with a solid mass content >90 % was prepared from the cross‐linked polymer network, and demonstrated fast Li+ conduction at a low temperature, high mechanical strength, and stable interfacial chemistry. As a result, solid‐state lithium‐sulfur batteries employing the new electrolyte delivered high reversible capacity and long cycle life at 25 °C, 0 °C and −10 °C to serve energy storage at complex environmental conditions. [ABSTRACT FROM AUTHOR]

Silicon oxide‐graphite (SiOx‐G) composites are promising anode materials for building practical high‐energy Li‐ion batteries. To acquire long and safe operation of battery, extensive efforts are made to maintain stable Li storage of SiOx‐G against materials aging and the accompanied performance fade. While previous studies mostly focus on the cycling aging, the calendar aging occurred during battery storage at a high state of charge or high temperature has not received sufficient attention. In this work, a mechanism study on the calendar aging chemistry of fully lithiated SiOx‐G electrodes in half‐cells both at ambient and high temperature (60 °C) is performed. Unmodified SiOx is employed as active materials to inspect the change of thermodynamics properties in the bulk and at interfaces. By excluding the interference from cathode, it is revealed that besides aggravated parasitic reactions happening at interface, Li migration from the lithiated graphite to the vicinal SiOx particles is also responsible for calendar aging of SiOx‐G electrodes, and high‐temperature storage notably accelerates the aging process. This work enriches the fundamental understandings about the multifactor‐coupled aging process of anode materials and sheds lights on rational materials design toward improved calendar life of a high‐energy rechargeable battery. [ABSTRACT FROM AUTHOR]

C2‐functionalized pyrimidine derivative is a family of important nitrogen heterocyclic compounds due to their unique structure and multiple reaction sites. In this work, a novel method for the synthesis of C2‐functionalized pyrimidine derivatives through phenylalkynes and pyrimidine disulfides under ambient conditions is proposed. The reaction can be triggered by adding catalytic amounts of cesium fluoride, which is characterized by free‐catalyst and special activator. Importantly, this reaction has good compatibility with substrates substituted by electron‐donating and electron‐withdrawing groups at C4. Density functional theory (DFT) calculations also indicates that the production of C2‐functionalized pyrimidine derivatives is more favourable. [ABSTRACT FROM AUTHOR]

High‐energy lithium‐ion batteries built with silicon‐based anode materials are usually associated with short cycle lives due to mechanical failure at an anode level and more importantly, due to electrochemical failure at a cell level as a result of irreversible consumption of cathode Li during initial charge. (Electro)chemical prelithiation has shown promises to compensate initial Li loss and improve cycling performance of the battery. However, previous strategies applied directly at anode or cathode could raise concerns on safety and degraded electrode structure, and are less compatible with industrial manufacture of batteries. Here, a new concept of prelithiation by lithiation agents supported functional separator, which is highly adaptive to electrode preparation, battery manufacture and formation, and is capable of, by simply adjusting cell voltage, not only replenishing cathode Li loss but re‐uptaking anode Li to inhibit local over‐lithiation and dendrite formation, is shown. By employing the functional separator, a 3‐Ah Li‐ion pouch cell that pairs a silicon‐based anode and a high‐nickel layered oxide cathode demonstrates stable energy output of >330 Wh kg−1 and much improved cycling performance. [ABSTRACT FROM AUTHOR]

An artificial "salt-in-polymer" SEI, composed of poly-(1,3-dioxolane) and high-modulus fluorinated products generated from the in situ decomposition of Li salts, was constructed on the surface of Li-MSiOx particles. This LiF-rich SEI helps to maintain the structural integrity of Li-MSiOx particles and improves the Li storage reversibility of the Li-MSiOx anode. [ABSTRACT FROM AUTHOR]