Silicon nanosheets are fascinating anode materials for lithium-ion batteries because of their high specific capacities, structural stability, and fast kinetics in alloying/dealloying with Li. The nanosheets can be synthesized through chemical vapor deposition (CVD), topochemical reaction, and templating method. After coating with a carbon nanolayer, they exhibit enhanced electrochemical performance. However, it is challenging to synthesize ultrathin carbon-coated silicon nanosheets. In this work, porous silicon/carbon (pSi/C) composite nanosheets are synthesized by reducing the carbon-coated expanded vermiculite with metallic Al in the molten salts. The as-prepared pSi/C nanosheets retain the layered nanostructure of vermiculite, with a thickness of less than 50 nm. The carbon nanolayer serves as the diffusion barrier and mechanical support for the growth of mesoporous silicon nanosheets. The anode of pSi/C nanosheets achieves remarkable electrochemical performance, exhibiting a reversible capacity of 1837 mA h g −1 at 4 A g −1 and retaining 71.5% of the initial capacity after 500 cycles. The process can be extended to the synthesis of the pSi/C composite nanotube by using other carbon-coated silicate templates such as halloysite.

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Flame spray pyrolysis was a process to produce oxide nanoparticles in a self-sustaining flame. When the produced nanoparticles were deposited on a substrate, nanostructured oxide thin films could be obtained. However, the size of the thin film was usually limited by the fixed substrate. Here, we demonstrated that thin film with a large area could be deposited by using the moving substrate, which was precisely controlled by servo motors. As a result, the flame tip could scan over the substrate and deposit the nanoparticles on it line by line, analogues to a printing process called flame-assisted printing (FAP). As an example, nanostructured bismuth-oxide thin films with a size of up to 20 cm × 20 cm were deposited with the FAP process. The bismuth-oxide thin film exhibited a stable electrochromic property with a high modulation of 70.5%. The excellent performance could be ascribed to its porous nanostructure formed in the FAP process. The process can be extended to deposit other various oxides (e.g., tungsten-oxide) thin films with a large size for versatile applications.