Toward Sustainable Polymer Materials for Rechargeable Batteries: Utilizing Natural Feedstocks and Recycling/Upcycling of Polymer Waste.

The ever-increasing demand for rechargeable battery systems in the era of electric vehicles has spurred extensive research into developing polymeric components for batteries, such as separators, polymer electrolytes, and binders. However, current battery systems rely on expensive and nonrenewable resources, which potentially have a negative environmental impact. Therefore, polymer materials derived from natural resources have gained significant attention, primarily due to their cost-effective and environmentally sustainable features.

Interweaving Elastic and Hydrogen Bond-Forming Polymers into Highly Tough and Stress-Relaxable Binders for High-Performance Silicon Anode in Lithium-Ion Batteries.

A central challenge in practically using high-capacity silicon (Si) as anode materials for lithium-ion batteries is alleviating significant volume change of Si during cycling. One key to resolving the failure issues of Si is exploiting carefully designed polymer binders exhibiting mechanical robustness to retain the structural integrity of Si electrodes, while concurrently displaying elasticity and toughness to effectively dissipate external stresses exerted by the volume changes of Si. Herein, a highly elastic and tough polymer binder is proposed by interweaving polyacrylic acid (PAA) with poly(urea-urethane) (PUU) elastomer for Si anodes.

Regulating Na Electrodeposition by Sodiophilic Grafting onto Porosity-Gradient Gel Polymer Electrolytes for Dendrite-Free Sodium Metal Batteries.

Sodium metal batteries have been emerging as promising candidates for post-Li battery systems owing to the natural abundance, low costs, and high energy density of Na metal. However, exploiting an Na metal anode is accompanied by uncontrolled Na electrodeposition, particularly concerning dendrite growth, hampering practical Na metal battery applications. Herein, we propose sodiophilic gel polymer electrolytes with a porosity-gradient Janus structure to alleviate Na dendrite growth.

Dendrite-Suppressing Polymer Materials for Safe Rechargeable Metal Battery Applications: From the Electro-Chemo-Mechanical Viewpoint of Macromolecular Design.

Metal batteries have been emerging as next-generation battery systems by virtue of ultrahigh theoretical specific capacities and low reduction potentials of metallic anodes. However, significant concerns regarding the uncontrolled metallic dendrite growth accompanied by safety hazards and short lifespan have impeded practical applications of metal batteries. Although a great deal of effort has been pursued to highlight the thermodynamic origin of dendrite growth and a variety of experimental methodologies for dendrite suppression, the roles of polymer materials in suppressing the dendrite growth have been underestimated.

A Phase-Canceled Backing Layer for Ultrasound Linear Array Transducer: Modeling and Experimental Verification.

In this study, a phase-canceled backing layer for ultrasound linear array transducer is presented. The proposed backing layer is composed of multiple blocks operated by a phase inversion technique. Inside the proposed backing layer, the phase of the reflected signals can be canceled by adjusting acoustic impedance, piezoelectric layer contact area, and thickness of each block constituting the backing layer.

Phase-Inverted Multifrequency HIFU Transducer for Lesion Expansion: A Simulation Study.

It has been well known that the treatment time of high-intensity focused ultrasound (HIFU) surgery can be reduced by expanding the focal area per sonication. Previously, a dual-concentric transducer using phase-inverted signals was proposed to axially extend the focal area, but it has suffered from the deep notch point between two focal lobes. In this paper, we propose the improved HIFU transducer with dual-concentric aperture driven by phase-inverted multifrequency signals based on an inversion layer technique.

Preparation of Conductive Carbon Films from Novolac Resins by Ion Beam Irradiation and Carbonization.

In this study, thin carbon films with good electrical properties were prepared using commercial novolac resins by ion beam irradiation and carbonization. Novolac films were irradiated with ion beams and then carbonized under inert atmosphere. Based on the FTIR and UV results, the novolac resins were found to be crosslinked by ion beam irradiation without any additives.

Desorption of micropollutant from spent carbon filters used for water purifier.

In this study, to examine the accumulated micropollutants in the spent carbon filter used in the water purifier, first, the method to desorb micropollutant from the activated carbon was developed and optimized. Then, using this optimized desorption conditions, we examined which micropollutants exist in spent carbon filters collected from houses in different regions in Korea where water purifiers were used. A total of 11 micropollutants (caffeine (CFF), acetaminophen (ACT), sulfamethazine (SMA), sulfamethoxazole (SMZ), metoprolol (MTP), carbamazepine (CBM), naproxen (NPX), bisphenol-A (BPA), ibuprofen (IBU), diclofenac (DCF), and triclocarban (TCB)) were analyzed using LC/MS-MS from the spent carbon filters.