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The larger ionic radius of potassium ions than that of lithium ions significantly limits the accomplishment of rapid diffusion kinetics in graphite electrodes for potassium-ion batteries (PIBs), resulting in comparatively poor rate performance and cycle stability. Herein, we report a high-rate performance and cycling stability amorphous carbon electrode achieved through nitrogen and phosphorous co-doping. The as-prepared N, P co-doped carbon electrodes have distinct 3D structures with large surface areas, hierarchical pore architectures, and increased interlayer spaces resulting from the direct pyrolysis of supramolecular self-assembled aggregates without templates. The obtained electrode N3P1 exhibits a reversible specific capacity of 258 mAh·g−1 at a current density of 0.1 A·g−1 and a good long-term cycle performance (96.1% capacity retention after 800 cycles at 0.5 A·g−1). Kinetic investigations show that the N3P1 electrode with the well-developed porous structure and large number of surface defects exhibits capacitive-driven behavior at all scan rates, which may be attributed by N and P co-doping. Ex-situ transmission electron microscopy analyses in the fully discharged and charged states demonstrate structural stability and reversibility owing to the expanded interlayer space. The suggested synthesis approach is simple and effective for producing heteroatom-doped carbon materials for PIBs and other advanced electrochemical energy storage materials. [ABSTRACT FROM AUTHOR]

The integration of metal–organic frameworks (MOF) into three-dimensional (3D) architectures has emerged as a promising strategy for enhancing the performance of energy storage devices. However, current approaches to achieve this integration are limited, especially for combining two-dimensional (2D) materials with MOFs to form complex 3D structures. In this study, 3D MXene-based microspheres encapsulating MOF-derived ZnSe@NC nanoparticles (3D MX/ZnSe@NC) were successfully fabricated by spray drying. The 3D structure effectively prevented restacking of MXene nanosheets and provided a large surface area with abundant ion storage sites. The uniform distribution of the ZnSe@NC nanoparticles within the MXene matrix not only prevented the aggregation of ZnSe crystals during cycling but also enhanced the electrical conductivity. Therefore, 3D MX/ZnSe@NC exhibited remarkable cycling stability (238 mA h g−1 at 0.5 A g−1 after 1000 cycles) and excellent rate performance (110 mA h g−1 at 2.0 A g−1), promoting its use as an anode material for potassium-ion batteries (PIBs). Furthermore, the K-ion storage mechanism was investigated to elucidate the reasons for the high performance of 3D MX/ZnSe@NC. The facile synthesis method and exceptional performance highlight the potential of 3D MX/ZnSe@NC as a high-performance anode material for PIBs. These findings contribute to the development of advanced electrode materials for next-generation energy storage devices. [ABSTRACT FROM AUTHOR]

Summary: Potassium ion batteries (KIBs) have attracted considerable attention as a next‐generation large‐scale energy storage system. Due to the large diameter of K+ ions, developing advanced electrode materials to achieve high‐performance KIBs is challenging. In this paper, one‐dimensional (1D) hybrid nanostructures comprising a MoSe2 core and a CoSe2/N‐doped carbon shell (denoted as MC‐Se@NC) are successfully synthesized by thermal treatment of Co‐based metal‐organic framework (ZIF‐67)‐coated MoO3 nanorods. The unique 1D morphology and synergistic effect between the different elements provide sufficient electrochemical reaction sites and facilitate the reaction kinetics. Further, the N‐doped carbon coating alleviates the volume fluctuation and pulverization of the active materials during cycling and improves the electrode conductivity. Accordingly, when applied to KIBs, the MC‐Se@NC anode delivers a high reversible capacity of 327 mA h g−1 at 0.5 A g−1 after 150 cycles, and remarkable rate capability of 190 mA h g−1 at 2.0 A g−1. Furthermore, to explore the practical application of MC‐Se@NC anode, a K‐ion full cell consisting of MC‐Se@NC anode and Prussian blue cathode is fabricated and characterized. As a demonstration, a light‐emitting diode (LED) is successfully powered by the K‐ion full cell. These excellent electrochemical properties of MC‐Se@NC present possibilities for the commercialization of KIB‐based large‐scale energy storage systems. [ABSTRACT FROM AUTHOR]

Summary: Sodium‐ion batteries (SIBs) and potassium‐ion batteries (KIBs) have received much attention as next‐generation energy storage systems owing to the abundance. Nevertheless, they face great challenges in the design of optimum electrode materials for practical applications. Herein, we prepared a unique two‐dimensional structured composite consisting of N‐doped carbon‐coated CoSe2 nanocrystals and MXene nanosheets (CoSe2@NC/MX) for efficient electrochemical Na‐ and K‐ion storage. In this strategy, a Co‐based zeolitic imidazole framework (ZIF‐67) was deposited on the surface of MXene nanosheets, and the subsequent selenization process resulted in the transformation of the ZIF‐67 into CoSe2@NCs. The unique structure can shorten the transport pathways for electrons/ions and provide sufficient space to accommodate the volume change of the active materials. Furthermore, the N‐doped carbon matrix and MXene can enhance the robustness of the electrode materials. Accordingly, the composites exhibited enhanced electrochemical performance in terms of cycle stability (317 mA h g−1 after 200 cycles at 0.5 A g−1) and rate capability (343 mA h g−1 at 7.0 A g−1) for SIBs. For KIBs, they exhibited a high reversible capacity of 358 mA h g−1 at 0.5 A g−1 after 100 cycles and 276 mA h g−1 at a high rate of 2.0 A g−1. [ABSTRACT FROM AUTHOR]

Portulaca oleracea L. is a traditional oriental medicine known for its pharmacological effects. The present study aimed to investigate the immunostimulatory effects of PPCE on cyclophosphamide-stimulated rat model and in isolated spleen cells. The result showed that PPCE exerted an immunostimulatory effect in vivo and in vitro. Specifically, PPCE significantly enhanced splenocyte proliferation and upregulated inflammatory cytokines (IL-2, IL-12, TNF-α, and IFN-γ) and NK cell activity in vitro. The immunostimulatory effect was further investigated through various immunological assays. Oral administration of PPCE increased the swimming time and number of immune cells in rats. Histological analysis revealed that PPCE administration exerted splenic recovery. Thus, P. oleracea L. based complex extracts may be used as an immunostimulatory agent in medicine or functional foods. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the immunity-enhancing effects of Orostachys japonicus A. Berger (OJ). To examine the immune protective effect in vitro, primary mouse splenocytes were treated with water or ethanol extracts of OJ in the absence or presence of cyclophosphamide (CY), which is a cytotoxic, immunosuppressive agent. The extracts increased the propagation of splenocytes and inhibited CY-induced cytotoxicity. Further, to examine the immunostimulatory effects in vivo, adult Wistar rats were orally administered OJ extracts with or without CY treatment. With the administration of OJ extracts, CY-treated immunosuppressed rats showed improved physical endurance, as assessed by the forced swim test. In addition, extract administration increased not only the number of immunity-related cells but also the levels of plasma cytokines. OJ extracts also recovered splenic histology in CY-treated rats. These findings suggest that an OJ regimen can enhance immunity by increasing immune cell propagation and specific plasma cytokine levels. [ABSTRACT FROM AUTHOR]