Yutong Wu

Modified montmorillonite nanosheets with well-tailored interlayer spacing and surface chemistry by quaternary ammonium salts were used to improve Zn anodes for alleviating the interfacial challenges in zinc–iodine batteries.

A systematic carbon-host comparison reveals how polyiodide confinement and charge transport jointly determine practical aqueous Zn–I ₂ battery performance.

Aqueous zinc-based battery technologies have attracted increasing interest toward safe and sustainable energy storage. Nonetheless, Zn metal anodes face huge challenges in aqueous systems such as serious dendrite growth, corrosion, hydrogen gas evolution, and self-discharge by redox-active species shuttle like polyiodide. Defective TiO_2-x nanoparticles have been proven effective to address the anode interfacial issues, while the structural tunability of TiO_2-x materials with facile fabrication remains to be further explored for advancing Zn chemistry. Herein, we report an effective artificial solid electrolyte interphase (a-SEI) strategy using a core-shell defective TiO_2-x-based nanocomposite for improving Zn anodes. This mesoporous a-SEI endows sufficient active sites, improved electrolyte wettability, and robust interface. More importantly, the defective a-SEI can remarkably improve the zinc affinity that guides its plating and lower the HER reactivity, as evidenced by ex-situ and in situ measurements. Consequently, the defective a-SEI-modified Zn anodes achieve a much more stabilized cycling performance in both symmetric cells and Zn-I₂ full cells. Briefly, this work offers a feasible a-SEI solution and broadens the structure scope of TiO_2-x materials for advancing Zn chemistry.

A membrane is required for conventional zinc-iodine aqueous batteries, since soluble polyiodides cross over to the anode side and react with zinc metal spontaneously. Making the battery membraneless increases ion transport and reduces its cost and overall footprint. In this paper, a membraneless Zn-I₂ aqueous battery is demonstrated, employing a complexing agent, 1-butyl-1-methylpyrrolidinium iodide (MBPI), to promote the formation of I₅^--containing, phase-separated polyiodides upon charging, to minimize self-discharge and suppress Zn dendrite growth. With an additional 0.3 M MBPI in 4 M ZnI₂ electrolyte, the membraneless battery achieved 65 cycles with >85% Coulombic efficiency, whereas the MBPI-free control failed immediately. Additionally, a volumetric capacity of 14.3 Ah L^-1 was achieved, surpassing those of most membraneless batteries reported to date regardless of redox chemistry, and underscores the potential of complexing agents in simplifying the architecture of conventional Zn-I₂ flow batteries.

Oxygen vacancy engineering plays a crucial role in regulating surface chemistry for managing redox behaviors. However, controllable implantation of oxygen vacancy and safe and cost-effective production remain challenging. Herein, we report a general molten zinc reduction technology to prepare oxygen-deficient oxides with tunable vacancy content, synthetic universality, and industrial compatibility under mildly elevated temperature. Taking TiO₂ as an example, theoretical study demonstrates thermodynamically favorable zinc affinity on TiO₂ with increasing surface coverage supporting molten Zn supply. Featuring favorable electronic structures and inferior hydrogen evolution activity, TiO_2-x nanoparticles were used to decorate aqueous Zn anodes, which demonstrate much improved cycling stability, verified by theoretical and in situ and ex situ investigations. Eventually, zinc-iodine batteries were assembled using modified Zn anodes, which achieved favorable cycling performance due to the regulated anode redox and alleviated self-discharge behaviors. This work provides a general oxygen vacancy engineering technology with an in-depth understanding for durable aqueous zinc batteries and related systems.

Fully π-conjugated polymers consisting of plane and rigid aromatic units present a fantastic optoelectronic property, a promising candidate for printed and flexible optoelectronic devices. However, obtaining high-performance conjugated polymers with an excellent intrinsically flexible and printable capacity is a great challenge due to their inherent coffee-ring effect and brittle properties. Here, we report an asymmetric substitution strategy to improve the printable and stretchable properties of deep-blue light-emitting conjugated polymers with a strong inter-aggregate capillary interaction for flexible printed polymer light-emitting diodes. The loose rod-shaped stacking of asymmetric conjugated polymers chain in the precursor printed ink makes it easier to improve the intrinsic stretchability of inkjet-printed films. More interestingly, the anisotropic shape rod-like aggregate of conjugated polymers chains also induced a strong capillary interaction and further suppressed the coffee-ring effect, which is more likely to allow for uniform deposition during printed processing and form uniform printed films.