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Designing metal/C nanocomposites has been a prevalent strategy to address the volume expansion issue of alloying metal Na-ion battery (NIB) anodes but typically suffers from poor volumetric capacity. Here, micrometer-sized nanoporous Sb/C anode with high volumetric capacity and outstanding electrochemical performance is successfully synthesized using facile synthesis of a new class of solid-state reduction chemistry. The resulting Sb/C composite, containing 10 wt % C, possesses the combination of unique structural characteristics, including (1) micrometer-sized secondary particle, enabling high particle density; (2) nanoscale Sb crystallites, permitting reversible phase transformation during cycling; and (3) uniformly distributed nanoporosity, providing accommodation for Sb expansion and facile Na-ion diffusion. The Sb/C composite anode, showing outstanding cycling stability, exhibits a gravimetric capacity of 436 mAh g −1 -(Sb+C), a volumetric capacity of 427 mAh cm −3 and over 80% capacity retention at nearly 5 C rate, all of which substantially excel those of the conventional C-based anodes. In situ transmission X-ray microscopy analysis reveals fracture-free reversible and considerably reduced deformation of the composite particles during the sodiation/desodiation cycle. The synthesis method demonstrates general applicability to developing other alloying metal anodes for NIBs, as well as Li-ion batteries.

This paper presents four refined distance models to the application of forecasting short-term electricity price namely Euclidean norm, Manhattan distance, cosine coefficient, and Pearson correlation coefficient. The four refined models were constructed and used to select the days, which are like a reference day in electricity prices and loads, called similar days in this study. Using the similar days, the electricity prices of a forecast day were further obtained by similar day regression (SDR) and similar day based artificial neural network (SDANN). The simulation results of the case of the PJM (Pennsylvania, New Jersey and Maryland) interchange energy market indicate the superiority and availability of the selection 45 framework days and three similar days based on Pearson correlation coefficient model.

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Research on lithium ion batteries has attracted massive attention due to the development of electrical vehicles and portable devices as well as grid energy storage. Pursuit for higher capacity and better cycle life become crucial issue for lithium ion battery anode material. Among all the anode materials, silicon is one of the most promising candidate due to its high theoretical specific capacity (around 3579mAh/g). Graphite, which is the stae-of-the-art commercialized anode material, is known for its stable performance and high electrical conductivity. In this work, a high-capacity composite anode suitable for large-scale production has been synthesized and characterized by taking advantage of both silicon’s high capacity and graphite’s good stability. In this approach, maintaining good dispersion of nano-Si is a critical requirement, and the effects of different dispersants and polymeric binders, which also serve as carbon precursors, have been investigated. Silicon/carbon/graphite composites exhibit high capacity and better cycle life than simple mixing of silicon and graphite powder have been achieved. Figure 1