RESUMO
10.1002/advs.202203058 Adv. Sci. 2022, 9, 2203058 The above article from Advanced Science, published online on 21 July 2022 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202203058), has been retracted by agreement between the authors, the Editor-in-Chief, Kirsten Severing, and Wiley-VCH GmbH. The retraction has been agreed as the article is based on research results and data that the authors were not authorized to use. Moreover, the majority of co-authors have been listed despite insufficient qualification for contributorship.
RESUMO
10.1002/advs.202202550 Adv. Sci.2022, 9, 2202550 The above article from Advanced Science, published online on 5 June 2022 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202202550), has been retracted by agreement between the authors, the Editor-in-Chief, Kirsten Severing, and Wiley-VCH GmbH. The retraction has been agreed as the article is based on research results and data that the authors were not authorized to use. Moreover, the majority of co-authors have been listed despite insufficient qualification for contributorship.
RESUMO
Liquid sodium-potassium (Na-K) alloy has the characteristics of high abundance, low redox potential, high capacity, and no dendrites, which has become an ideal alternative material for potassium/sodium metal anodes. However, the high surface tension of liquid sodium potassium alloy at room temperature makes it inconvenient in practical use. Here, the Na-K as reducing agent treats with hydrazone linkages of covalent organic frameworks (COFs) and obtain the carbon-oxygen radical COFs (COR-Tf-DHzDM-COFs). The preparation method solves the problems that the preparation process of the traditional Na-K composite anode is complex and has high cost. The structures of the COR-Tf-DHzDM-COFs are characterized by X-ray diffraction ï¼XRD), fourier transform infrared (FT-IR), electron paramagnetic resonance (EPR), and solid-state NMR measurements. It is the first time that carbon-oxygen radical COFs from bulk COFs are constructed by one-step method and the operation is flexible, convenient, and high rate of quality, which is suitable for big production and widely used. The cycle stability of the composite Na-K anode is improved, which provides a new idea for the design of high-performance liquid metal anode.
RESUMO
Potassium-ion batteries (KIB) have similar energy storage mechanism with lithium-ion battery, but the potassium (K) resource is rich, which shows great potential for large-scale energy storage system. Recently, the anode materials of KIB studied mainly include carbon materials, transition metal oxides, and alloy materials. The amorphous hard carbon shows the best comprehensive performance, but its intercalation potential is close to 0 V (versus K+ /K), which is easy to cause K dendrite and brings security risks. The oxide materials have high capacity but high intercalation potential, low first cycle efficiency, and unstable cycle. Here, based on the understanding of the K intercalation mechanism of vanadium oxides, a novel zero strain anode material with layered structure of dual-ions (Na+ /K+ ) is designed (NaK(VO3 )2 V2 O5 ). The introduction of Na/K ion contributed to the transmission and further stabilized the structure. It has an excellent rate performance (10 A g-1 , up to 25 000th cycle), and its special K storage mechanism and zero-strain characteristics are revealed for the first time by ex situ scanning electron microscope, X-ray powder diffraction, X-ray photoelectron spectroscopy, and other test methods. Considering the excellent performance endowed by these unique inherent properties, NaK(VO3 )2 V2 O5 shows great potential for commercial anode materials and may promote the innovation of KIB.
