Enhanced Solar‐Driven‐Heating and Tough Hydrogel Electrolyte by Photothermal Effect and Hofmeister Effect

Abstract

Although plenty of progress and achievements are made on hydrogel electrolyte researches, the inherent inferior low‐temperature performance of hydrogel electrolyte is still a severe challenge for wider application on the energy storage devices, due to the high content of water within hydrogel. Herein, an enhanced solar‐driven‐heating composite hydrogel electrolyte and a solar‐driven‐heating graphene based micro‐supercapacitor are developed utilizing the photothermal conversion ability and self‐initiation of MoS2 nanosheets and additional Hofmeister effect. The MoS2 composite hydrogel electrolyte not only improves the reliability of micro‐supercapacitor owing to its splendid mechanical properties, but also endows the micro‐supercapacitor with superior low‐temperature electrochemical performance and broadens its operating environment to a much lower temperature (−56 °C), which should be attributed to the excellent ability in converting endless solar energy into required thermal energy. These efforts would construct a new application platform for solar energy conversion and present an efficient method to structure severe‐cold resistant solid state energy storage devices for next‐generation.

Antifreezing Hydrogel Electrolyte with Ternary Hydrogen Bonding for High‐Performance Zinc‐Ion Batteries

“…[36,37] Therefore, exploring a new salt with low concentration to confer the hydrogel electrolyte with adjustable mechanical property and high ionic conductivities at subzero temperatures is of great importance.The Hofmeister effect is one of the ubiquitous phenomenon in nature, including two distinct solvation behaviors for hydrogels regarded as the "salting out" effect of the kosmotropes and "salting in" effect of the chaotropes. [38][39][40][41][42] Current literatures have employed inorganic salts to tailor the mechanical property The new-generation flexible aqueous zinc-ion batteries require enhanced mechanical properties and ionic conductivities at low temperature for practical applications. This fundamentally means that it is desired that the hydrogel electrolyte possesses antifreezing merits to resist flexibility loss and performance decrease at subzero temperatures.…”

Reversible switching of polymeric gel structure and property by solvent exchange

“…The distinctive attributes of the dynamic polymeric gels, such as configurable mechanical behavior [1-6], external stimuliresponsiveness [7-13] and self-healing ability [14-17], underlie their extensive applications in materials science, ranging from tissue-adaptive biomaterials [18][19][20] through high-efficient energy materials [21][22][23] to intelligent information materials [24][25][26]. For instance, stiffness-changing trait (e.g., rigid-to-soft transition) is especially desired in medical devices, since the rigid state allows for the easy insertion, while the soft state favors biocompatibility with surrounding tissues [19,27].…”

Highly Flexible and Broad-Range Mechanically Tunable All-Wood Hydrogels with Nanoscale Channels via the Hofmeister Effect for Human Motion Monitoring

“…The excellent mechanical properties of allwood hydrogels are mainly attributed to the strong hydrogen bonding, physical entanglement, and van der Waals forces between cellulose nanofibers, lignin molecules, and PVA chains, and the toughening effect of cellulose nanofibers. Induced by the Hofmeister effect, crystal domains and numerous hydrogen bonds are formed in the hydrogel network, resulting in the high mechanical strength of the allwood hydrogels [35,38,[47][48][49]. The effects of lignin content, PVA content, and salting time on the tensile strength of all-wood hydrogels in the L-directional are further 1 3 investigated.…”