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Energy and environmental issues have attracted increasing attention globally, where sustainability and low-carbon emissions are seriously considered and widely accepted by government officials. In response to this situation, the development of renewable energy and environmental technologies is urgently needed to complement the usage of traditional fossil fuels. While a big part of advancement in these technologies relies on materials innovations, new materials discovery is limited by sluggish conventional materials synthesis methods, greatly hindering the advancement of related technologies. To address this issue, this review introduces and comprehensively summarizes emerging ultrafast materials synthesis methods that could synthesize materials in times as short as nanoseconds, significantly improving research efficiency. We discuss the unique advantages of these methods, followed by how they benefit individual applications for renewable energy and the environment. We also highlight the scalability of ultrafast manufacturing towards their potential industrial utilization. Finally, we provide our perspectives on challenges and opportunities for the future development of ultrafast synthesis and manufacturing technologies. We anticipate that fertile opportunities exist not only for energy and the environment but also for many other applications.

The electrolyte, a key component for the successful operation of energy materials, is greatly affected by its solvents. The influence of solvents on the electrochemical performance of a LiFePO4/C composite cathode was investigated at various operating temperatures. The reaction kinetics of the LiFePO4/C composite electrode, including changes of rate capability, redox potential, polarization degree, electrode reaction process, exchange current densities, and activation energies, were evaluated using various techniques. The composition and volume ratio of solvents greatly affect the electrode kinetics. In the mixed solvents of ethylene carbonate (EC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC), EMC is beneficial for the room temperature performance, while the substitution of 20 vol % of EMC by ethyl acetate (EA) is good for the low temperature performance. When 30 vol % of DMC is substituted by 10 vol % of EMC and 20 vol % of EA, the exchange current density increases from 0.022 to 0.038 mA cm−2 at −20 °C, while the activation energy of the charge-transfer process decreases from 48.36 to 33.01 kJ mol−1. Possible mechanisms for improving the electrochemical performance using different solvents have been analyzed. These results are significant for the exploration of appropriate electrolytes for the extensive applications of LiFePO4/C composite electrodes.

Lithium-oxygen (Li-O2) cells are a promising power source, and carbons are an attractive non-metal catalyst for air electrodes. To improve the electrochemical performance, various carbons are heated in an inert atmosphere. It is found that heat treatment at 900 C can differently improve the electrochemical performance of multiwalled carbon nanotubes (CNTs), acetylene carbon black (AB) and activated carbon (AC), but the improvement of CNTs is the most obvious. After heat treatment, the peak current density of the oxygen reduction reaction (ORR) and the 1st discharge capacity of CNTs increase ∼30% and ∼125%, respectively, while the charge transfer reaction resistance and the Warburg diffusion resistance decrease ∼7.0% and ∼11.1%, respectively. AC has the highest charge capacities and capacity retention ratio in spite of little influence by heat treatment. The possible mechanism and reasons are analyzed using different techniques. Microstructure is superior to conductivity for enhancing the rechargeability and the cyclability, and heat treatment is effective for some carbon materials in improving the electrochemical performance of Li-O2 cells. © 2014 Elsevier Ltd.