Direct Fabrication of PET-Based Thermotolerant Separators for Lithium-Ion Batteries with Ion Irradiation Technology.

Lithium-ion batteries (LIBs) play a pivotal role as essential components in various applications, including mobile devices, energy storage power supplies, and electric vehicles. The widespread utilization of LIBs underscores their significance in the field of energy storage. High-performance LIBs should exhibit two key characteristics that have been persistently sought: high energy density and safety. The separator, a critical part of LIBs, is of paramount importance in ensuring battery safety, thus requiring its high thermal stability and uniform nanochannels. Here, the novel ion-track etched polyethylene terephthalate (ITE PET) separator is controllably fabricated with ion irradiation technology. Unlike conventional polypropylene (PP) separators, the ITE PET separator demonstrated vertically aligned nanochannels with uniform channel size and distribution. The remarkable characteristics of the ITE PET separator include not only high electrolyte wettability but also exceptional thermal stability, capable of withstanding temperatures as high as 180 °C. Furthermore, the ITE PET separator exhibits a higher lithium-ion transfer number (0.59), which is advantageous in enhancing battery performance. The structural and inherent advantages of ITE PET separators contribute to enhance the C-rate capacity, electrochemical, and long-term cycling (300 cycles) stability observed in the corresponding batteries. The newly developed method for fabricating ITE PET separators, which possess high thermal stability and a uniform channel structure, fulfills the demand for high-temperature-resistant separators without requiring any modification procedures. Moreover, this method can be easily scaled up using simple processes, making it a competitive strategy for producing thermotolerant separators.

Confinement and passivation of perovskite quantum dots in porous natural palygorskite toward an efficient and ultrastable light-harvesting system in water.

Perovskite quantum dots (QDs) are promising as representative candidates to construct next-generation superior artificial light-harvesting systems (ALHSs). However, their high sensitivity to external environments, especially to water, imposes a stringent limitation for their actual implementation. Herein, by interface engineering and encapsulation with natural palygorskite (PAL), a water-resistant light-harvesting CsPbBr3@PAL antenna was prepared. Molecular dynamics simulations further confirm a significant shielding protection of the PAL matrix to CsPbBr3, facilitating exceptional stability of the CsPbBr3@PAL antenna when exposed to air for 10 months, to 150 °C thermal stress, and even to water for more than 30 days, respectively. Furthermore, as a result of in situ encapsulation of the PAL matrix and defect passivation caused by H-bonding and coordination-bonding interaction, the CsPbBr3@PAL antenna in water shows a substantially enhanced photoluminescence quantum yield (36.2%) and longer lifetime. After sequentially assembling Eosin Y and Rose Bengal in the pores of the PAL matrix, RB-ESY-CsPbBr3@PAL with a sequential two-step efficient Förster resonance energy transfer process exhibited extremely enhanced photocatalytic activity toward Friedel-Crafts alkylation reactions in aqueous solution, 2.5-fold higher than that of corresponding ESY/RB. Our work provides a feasible strategy for the exploitation of ultra-stable halide perovskite-based ALHSs in aqueous media for solar-energy conversion.

Elliptical gold nanowires: controlled fabrication and plasmonic Fabry-Pérot resonances.

Nanowires (NWs) are essential building blocks of photonic devices for guiding light waves. However, the controlled synthesis of non-circular NWs remains challenging. Herein, we develop a bottom-up approach for the fabrication of high-quality elliptical gold NWs with finely tuned geometry engineering by using an advanced ion-track template technology. Compared to ordinary NWs, the rotational symmetry breaking leads to highly polarization-dependent plasmonic responses. Modal analysis shows that the lowest dipolar HE1 mode splits into two branches where the attenuation of the long-range branch decreases by 40%, while the short-range branch has a stronger enhanced near-field. Novel, to the best of our knowledge, plasmonic Fabry-Pérot resonances on finite NWs are measured. Our method can be extended to fabricate non-circular NWs with other materials, holding potential for novel applications from quantum to collective scales.