Although silicon nanowires (SiNW) have been widely studied as an ideal material for developing high-capacity lithium ion batteries (LIBs) for electric vehicles (EVs), little is known about the environmental impacts of such a new EV battery pack during its whole life cycle. This paper reports a life cycle assessment (LCA) of a high-capacity LIB pack using SiNW prepared via metal-assisted chemical etching as anode material. The LCA study is conducted based on the average U.S. driving and electricity supply conditions. Nanowastes and nanoparticle emissions from the SiNW synthesis are also characterized and reported. The LCA results show that over 50% of most characterized impacts are generated from the battery operations, while the battery anode with SiNW material contributes to around 15% of global warming potential and 10% of human toxicity potential. Overall the life cycle impacts of this new battery pack are moderately higher than those of conventional LIBs but could be actually comparable when considering the uncertainties and scale-up potential of the technology. These results are encouraging because they not only provide a solid base for sustainable development of next generation LIBs but also confirm that appropriate nanomanufacturing technologies could be used in sustainable product development.

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A novel Co 3 O 4 /N-doped porous carbon hybrid with dodecahedrons structure was synthesized by a facile, two-step, thermal transformation of a cobalt-based zeolitic imidazolate framework. Well-dispersed Co 3 O 4 nanoparticles were embedded in nitrogen-doped porous carbon networks, forming a unique nanopolyhedron. When tested as anode material for lithium-ion batteries, the hybrid exhibited superior electrochemical performance, including excellent rate capability of 560 mAh g −1 at 10 A g −1 which is close to 46% of the rate capacity at 100 mA g −1 , outstanding cycling stability with 91.7% capacity retention of the second cycle after 110 cycles, and considerably large discharge capacity of 1,730 mAh g −1 at 100 mA g −1. Moreover, the

Microbial electrolysis cells (MECs) can produce hydrogen gas from organic compounds in an energy‐efficient way by taking advantage of the potential generated by microorganisms. However, hydrogen evolution reaction (HER) in MECs is slow and thus requires catalysts. A challenge for MEC development therefore lies in the development of cost‐effective HER catalysts. In this study, a nanocomposite with molybdenum disulfide (MoS2) coated on highly conductive carbon nanotubes (CNTs) was synthesized as an alternative HER catalyst, and examined in an MEC for hydrogen production. Linear sweep voltammogram experiments demonstrated enhanced HER activity with increasing CNT content. The results suggest that conductivity may be the main limiting factor for overall HER catalysis by MoS2. MEC tests showed that MoS2/CNT‐90 achieved hydrogen production that was comparable to the Pt‐based catalyst. The low cost of the MoS2 composites will make it competitive as an effective HER catalyst for future MEC applications.

A multilayered structural silicon-reduced graphene oxide electrode with superior electrochemical performance was synthesized from bulk Si particles through inexpensive electroless etching and graphene self-encapsulating approach. The prepared composite electrode presents a stable charge-discharge performance with high rate, showing a reversible capacity of 2787 mAh g(-1) at a charging rate of 100 mA g(-1), and a stable capacity over 1000 mAh g(-1) was retained at 1 A g(-1) after 50 cycles with a high columbic efficiency of 99% during the whole cycling process. This superior performance can be attributed to its novel multilayered structure with porous Si particles encapsulated, which can effectively accommodate the large volume change during the lithiation process and provide increased electrical conductivity. This facile low-cost approach offers a promising route to develop an optimized carbon encapsulated Si electrode for future industrial applications.