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Abstract The striped flea beetle (SFB, Phyllotreta striolata) can cause serious harm to cruciferous crops in both the larval and adult stages. Presently, there are no other sustainable alternatives to the use of chemical pesticides for controlling SFB infestation. In this study, the use of a seed-pelletized coating of spinetoram effectively reduced the numbers of SFB and its feedings on the flowering cabbage seedlings, whereas, in combination with the insect-proof net, it controlled the SFB infestation throughout the cabbage growth period. The analysis of the pesticide residues in soil and different cabbage parts indicated the degradation dynamics of spinetoram. The concentration of spinetoram in cabbage parts decreased over time, while increased first and subsequently decreased in soil. Furthermore, estimation of the half-life of spinetoram revealed that via seed-palletized application spinetoram half-life was found to be 2.82 days in soil, 4.21 days in the root, 5.77 days in the stem, and 3.57 days in the leaf, respectively. Both the lower pesticide residues and the half-life of spinetoram in soil and cabbage parts suggested it to be a promising environment and food-safe pesticide in controlling SFB. Moreover, the seed-pelletized coating ensured a sustainable release of spinetoram that can reduce the pesticide application frequency and be cost-effective and pocket-friendly for the farmers.

Irreversible phase transition caused capacity fading has been considered as an obstacle for rechargeable batteries. An in-depth investigation of the irreversible phase transition is critical for understanding the reaction mechanism and developing advanced batteries. In this work, taking vanadium oxide and its alkali ion-stabilized intercalation compounds (A-V-O, A = Li, Na, K) as prototypes, utilizing operando characterizations, we discovered coupled discontinuous (interlayer)-continuous (intralayer) transitions in the stabilized multielectron intercalation cathodes. The highly ordered crystal of vanadium pentoxide irreversibly transfers to a disordered/amorphous structure after the first cycle, whereas A-V-O enables reversible discontinuous lattice transitions at the interlayer pathway for facilitating lithium diffusion. Among the A-V-O family, K-V-O, with the highest capacity retention, shows a coupled discontinuous-continuous transition, which exhibits a continuous transition and the minimum volume change at the V-O intralayer during lithium intercalation/deintercalation. These coupled discontinuous-continuous lattice transitions were captured for the first time in cathode materials. It implies that the suitable ion intercalation induced continuous intralayer transition inhibits the irreversible ion intercalation and phase transition. [ABSTRACT FROM AUTHOR]

A nano-phenazine@Ketjen black (nPZ/KB) composite was prepared as an anode for aqueous rechargeable batteries by an in situ dissolution–precipitation method. Due to the uniform precipitation of nano-phenazine on the highly conductive and hierarchical porous Ketjen black surface, it enabled ultrafast transfer of metal cations (Na+, K+, Zn2+etc.) and electrons to almost all the electrochemically active sites of phenazine molecules. Hence, nPZ/KB not only realized the full utilization of a theoretical capacity of 298 mA h g−1 but also exhibited a high rate discharge capacity of 102 mA h g−1 under 100 C in 6 M KOH. Furthermore, the nPZ/KB composite achieved an ultralong cycle life of 100 000 times with a high capacity retention of 76% because of the insolubilities of both phenazine and its reduction products in aqueous electrolytes. The excellent performance of the nPZ/KB-NiOOH battery and nPZ/KB-activated carbon pseudocapacitor demonstrated great promise for grid-scale energy storage devices. [ABSTRACT FROM AUTHOR]

Phase engineering of nanomaterials (PEN) is critically important for the preparation of nanomaterials with new phases, which are key for the investigation of phase‐dependent physicochemical properties and applications. This essay presents the state‐of‐the‐art development of PEN for the unique properties of nanomaterials with unconventional phases and their applications in energy storage and conversion and catalytic reactions. Finally, personal perspectives on the challenges and future opportunities of PEN in various applications are also provided. [ABSTRACT FROM AUTHOR]

VS2 is one of the attractive layered cathodes for alkali metal‐ion batteries. However, the understanding of the detailed reaction processes and energy storage mechanism is still inadequate. Herein, the Li+/Na+/K+ insertion/extraction mechanisms of VS2 cathode are elucidated on the basis of experimental analyses and theoretical simulations. It is found that the insertion/extraction behavior of Li+ is partially irreversible, while the insertion/extraction behavior of Na+/K+ is completely reversible. The detailed intermediates and final products (Li0.33VS2, LiVS2, Na0.5VS2, NaVS2, K0.6VS2, KzVS2, z > 0.6) during the discharging/charging processes are identified, indicating that VS2 undergoes different phase transitions and solid–solution reactions in different battery systems, which have a great influence on the battery performance. Moreover, the diffusion of Na+ in VS2 cathode is demonstrated to be much slower than that of Li+ and K+. Such mechanistic research provides a reference for in‐depth understanding of energy storage in layered transition metal sulfides/selenides. [ABSTRACT FROM AUTHOR]

In situ X-ray diffraction (XRD), as a widely used tool in probing the structure evolution in electrochemical process as well as the energy storage and capacity fading mechanism, has shown great effects with optimizing and building better batteries. Based on the research progresses of in situ XRD in recent years, we give a review of the development and the utilization of this powerful tool in understanding the complex electrochemical mechanisms. The studies on in situ XRD are divided into three sections based on the reaction mechanisms: alloying, conversion, and intercalation reactions in lithium-ion batteries. The alloying reaction, in which lithium ions insert into Si, Sb, and Ge is firstly reviewed, followed by a discussion about the recent development of in situ XRD on conversion reaction materials (including metal oxides and metal sulfides) and intercalation reaction materials (including cathode materials and some structure-stable anode materials). As for sodium-ion batteries, we divide these researches on structure evolution into two categories: cathode and anode materials. Finally, the future development of in situ XRD is discussed. [ABSTRACT FROM AUTHOR]

Li-rich layered oxides have been in focus because of their high specific capacity. However, they usually suffer from poor kinetics, severe voltage decay, and capacity fading. Herein, a long-neglected Li-deficient method is demonstrated to address these problems by simply reducing the lithium content. Appropriate lithium vacancies can improve dynamics features and induce in situ surface spinel coating and nickel doping in the bulk. Therefore, the elaborately designed Li 1.098 Mn 0.533 Ni 0.113 Co 0.138 O 2 cathode possesses improved initial Coulombic efficiency, excellent rate capability, largely suppressed voltage decay, and outstanding long-term cycling stability. Specifically, it shows a superior capacity retention of 93.1% after 500 cycles at 1 C (250 mA g -1 ) with respect to the initial discharge capacity (193.9 mA h g -1 ), and the average voltage still exceeds 3.1 V. In addition, the discharge capacity at 10 C can be as high as 132.9 mA h g -1 . More importantly, a Li-deficient cathode can also serve as a prototype for further performance enhancement, as there are plenty of vacancies.

As a novel and potential transition metal dichalcogenide (TMDC), NbSe 2 has low ion diffusion barrier when applied in energy-storage systems, such as traditional lithium-ion batteries and novel magnesium-ion batteries (MIBs). In this work, we have developed a novel hexagonal NbSe 2 material with a nanosized surface via a facile microwave-hydrothermal method. The Li + -storage mechanism of NbSe 2 with surface conversion and internal intercalation is thoroughly revealed by in situ X-ray diffraction (XRD), ex situ high-resolution transmission electron microscopy, and ex situ scanning electron microscopy. Besides, Mg 2+ intercalation mechanism is confirmed via ex situ XRD and ex situ X-ray photoelectron spectroscopy for the first time. In addition, as the cathode for MIBs, NbSe 2 with a nanosized surface exhibits a high rate capacity of 101 mA h g -1 at 200 mA g -1 with a high discharge plateau at 1.30 V. Our work builds a deep understanding of ion-storage mechanisms in TMDCs and provides guidance for designing new electrode materials with high electrochemical performances.

The development of manganese dioxide as the cathode for aqueous Zn-ion battery (ZIB) is limited by the rapid capacity fading and material dissolution. Here, a highly reversible aqueous ZIB using graphene scroll-coated α-MnO 2 as the cathode is proposed. The graphene scroll is uniformly coated on the MnO 2 nanowire with an average width of 5 nm, which increases the electrical conductivity of the MnO 2 nanowire and relieves the dissolution of the cathode material during cycling. An energy density of 406.6 Wh kg -1 (382.2 mA h g -1 ) at 0.3 A g -1 can be reached, which is the highest specific energy value among all the cathode materials for aqueous Zn-ion battery so far, and good long-term cycling stability with 94% capacity retention after 3000 cycles at 3 A g -1 are achieved. Meanwhile, a two-step intercalation mechanism that Zn ions first insert into the layers and then the tunnels of MnO 2 framework is proved by in situ X-ray diffraction, galvanostatic intermittent titration technique, and X-ray photoelectron spectroscopy characterizations. The graphene scroll-coated metallic oxide strategy can also bring intensive interests for other energy storage systems., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)