No abstract

Traditional binders generally interact with silicon particles via weak van der Waals forces and consequently lack interactions between active materials after volume expansion. Water-soluble binders have recently garnered lots of attention as low-cost and environmentally benign aqueous media to overcome the main challenges with practical processing considerations. Herein, we report the development of a multifunctional polymeric binder having a three-dimensional network structure for silicon-based anodes, providing three advantages over traditional binders: greater structural integrity against expansion, stronger adhesion to anode components, and higher ionic conductivity. Diverse operando observations clearly show that the novel multifunctional binder mitigates the microstructural changes of silicon at nanoscale and microscale levels compared to conventional linear binders, resulting in a high electrochemical performance of approximately 1100 mAh g–1 even after 1000 cycles. Our systematic study on the effects of this multifunctional binder will be of great help in the rational design of polymer binders for advanced batteries.

Owing to the rise in global population and living standards, waste treatment has inevitably become a critical issue for a sustainable environment. In particular, for an effective recycling process, it...

The development of flexible electronic technology has led to convenient devices, including foldable displays, wearable, e‐skin, and medical devices, increasing the need for flexible adhesives that can quickly recover their shape while connecting the components of the device. Conventional pressure sensitive adhesives (PSAs) can improve recoverability via crosslinking, but often have poor adhesive strength. In this study, new types of urethane‐based crosslinkers are synthesized using m‐xylylene diisocyanate (XDI) or 1,3‐bis(isocyanatomethyl)cyclohexane (H6XDI) as a hard segment, and poly(ethylene glycol) (PEG) group as a soft segment. The PSA with the synthesized H6XDI‐PEG diacrylate (HPD) demonstrates a significantly improved recoverability compared to XDI‐PEG diacrylate and a conventional crosslinker 1,6‐hexanediol diacrylate (HDDA) while maintaining high adhesion strength (≈25.5 N 25 mm−1). The excellent recovery property of the PSA crosslinked with HPD is further confirmed by 100k folding tests and 10k multi‐directional stretching tests exhibiting high folding and stretching stability. PSA with HPD also shows high optical transmittance (> 90%) even after 20% straining, suggesting its applicability in fields that simultaneously require high flexibility, recoverability, and optical clarity such as foldable displays.