Processable Hydroxide Ink with Oriented Microstructure.

Abstract

Hydroxides are recognized as promising candidates for industrially relevant processes, including catalysis, energy conversion/storage, gas separation, etc. However, the intrinsic poor processability originating from their structural property greatly hinders their development in practical applications. Here, we report a unique yet processable highly-concentrated nickel/cobalt double hydroxide ink to meet the practical demand. The inner nanoflakes in ink possess a high width/thickness ratio (> 100), which endows the highly-concentrated ink (60mg mL-1 ) with liquid-like rheology properties. Further, the elliptical diffusive arc in small-angle X-ray scattering (SAXS) pattern and porous and ordered alignment morphology in cryogenic temperature scanning electron microscopy (Cryo-SEM) confirm the locally oriented arrangement of nanoflakes in the ink. Benefiting from this interior-ordered structure, the ink can be processed into meter-level film, continuous yarn, and rigid and free-standing aerogel, respectively. In particular, the films can be used as electrodes directly in aqueous zinc ion batteries and deliver a favorable capacity (382 mAh g-1 @ 200mA g-1 ) as well as long cycle stability (capacity retention rate of 88% @ 1000mA g-1 after 400 cycles). Moreover, the enlarged-batched fabrication with introduction of efficient thermal conduction in a 10 L reactor is also carried out successfully. Our results clarify the inner relationship between microstructure-rheology and mechanical engineering, thus paving the way to develop hydroxide-based products for future practical applications at the industrial level. This article is protected by copyright. All rights reserved.