the standard electrochemical potential of Na (2.71 V vs Na + /Na) is lower than that of Li (3.04 V vs Li + /Li), the successful academic and commercial experiences of LIBs can be referred by SIBs. Therefore, SIBs have been regarded as the most promising alternatives to LIBs. In the past few years, many novel materials have been developed and evaluated as electrode materials for SIBs. For instance, a number of transition metal oxides, transition metal sulfides and fluorides, polyanions, Prussian blue compounds, and organic polymers have been investigated as cathode materials for SIBs. [4][5][6] However, it seems that there are very limited options for SIB anodes. Only a few materials have shown satisfactory sodium storage performance, such as carbonaceous materials, metal alloys, metal oxides and sulfides, and Ti-based oxides (TiO 2 and sodium titanate). [7][8][9] Among them, carbonaceous materials, especially the hard carbons and heteroatom-doped carbons, are mostly investigated because of their low cost, abundant resource, and high electronic conductivity. [10][11][12][13][14] In addition, doping carbons with heteroatoms such as B, N, O, S, and P have been regarded as an effective method to improve the physicochemical properties of carbonaceous materials. [15,16] Among the heteroatom-doped carbons, N-doped carbons have become the most studied materials for improving the sodium storage performance over the past several years. It is also proved that doping with other heteroatoms can increase the sodium storage capacity by introducing defects, enhancing the conductivity, improving the porosity, or optimizing the interlayer of carbon. In recent years, several groups have reviewed the progress of carbonaceous materials for energy applications, such as LIBs, supercapacitors, fuel cells, and solar cells. For example, in 2013 Paraknowitsch and Thomas reviewed the development of carbon materials and their use in energy devices. [17] They suggested that S and P doping could induce the structural distortion and change the charge density of the carbons due to their different atom size and electronegativity from carbon, while B codoping could create synergistic effect on performance improvement. In 2015, Peng and co-workers presented the progress of carbonaceous electrode materials including fullerene, carbon nanotube, graphene, and mesoporous carbon for energy conversion and storage devices. [18] Particularly, N-doped multiwalled carbon nanotube have widely used in solar cells, while N-and B-doped graphene and N/P-codoped reduced graphene oxide have played important roles in LIBs. In 2016, Ji and co-workers focused Sodium-ion batteries (SIBs) show promising application in large-scale energy storage as future alternatives to lithium-ion batteries. Carbonaceous materials are attractive anode candidates for SIBs due to low cost, abundance, and high safety. In general, doping heteroatoms such as N, B, O, S, and P in carbon-based materials gives rise to high electronic mobility, good sodium mobility, and enhanced capacity, showi...

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Pyrite FeS has attracted extensive interest as anode material for sodium-ion batteries due to its high capacity, low cost, and abundant resource. However, the micron-sized FeS usually suffers from poor cyclability, which stems from structure collapse, exfoliation of active materials, and sulfur dissolution. Here, we use a synergistic approach to enhance the sodium storage performance of the micron-sized FeS through voltage control (0.5-3 V), binder choice, and graphene coating. The FeS electrode with the synergistic approach exhibits high specific capacity (524 mA h g), long cycle life (87.8% capacity retention after 800 cycles), and excellent rate capability (323 mA h g at 5 A g). The results prove that a synergistic approach can be applied in the micron-sized sulfides to achieve high electrochemical performance.

The oxetan-3-yl and azetidin-3-yl substituents have previously been identified as privileged motifs within medicinal chemistry. An efficient approach to installing these two modules into aromatic systems, using a nickel-mediated alkyl-aryl Suzuki coupling, is presented.