This review provides an overview of emerging ultrafast synthesis technologies for energy and environmental applications. Representative ultrafast methods include Joule heating, plasma, laser, infrared, microwave, and flame-assisted synthesis, etc.

Recycling of spent lithium-ion batteries is essential for the sustainable development of renewable energy technologies, as it promotes resource reuse and environmental protection. Recycling cathode materials is particularly important due to their high concentration of strategic elements. However, traditional recycling methods for cathode materials are often inefficient due to high energy consumption and prolonged operation time. Here, we present an efficient, one-step, nondestructive method for regenerating spent LiCoO2 cathodes within seconds. This method simultaneously achieves relithiation of the cathode material and repair of the crystal structure through rapid Joule heating. Compared to traditional repair methods, this process exhibits low energy consumption and shortened operation time. After an 8 s repair process, the regenerated LiCoO2 has a well-defined layered structure and is restored to its original electrochemical performance, with an initial discharge capacity of 133.0 mAh/g and good cycling performance. This work represents a potentially universal approach for the efficient direct regeneration of cathode materials.

Lithium metal is widely regarded as the "ultimate" anode for energy-dense Li batteries, but its high reactivity and delicate interface make it prone to dendrite formation, limiting its practical use. Inspired by self-assembled monolayers on metal surfaces, we propose a facile yet effective strategy to stabilize Li metal anodes by creating an artificial solid electrolyte interphase (SEI). Our method involves dip-coating Li metal in MPDMS to create an SEI layer that is rich in inorganic components, allowing uniform Li plating/stripping under a low overpotential over 500 cycles in carbonate electrolytes. In comparison, pristine Li metal shows a rapid increase in overpotential after merely 300 cycles, leading to failure soon after. Molecular dynamics simulations demonstrate that this uniform artificial SEI suppresses Li dendrite formation. We further demonstrated its enhanced stability pairing with LiFePO 4 and LiNi 1−x−y Co x Mn y O 2 cathodes, highlighting the proposed strategy as a promising solution for practical Li metal batteries.