Confinement of Zinc Salt in Ultrathin Heterogeneous Film to Stabilize Zinc Metal Anode.

Aqueous zinc metal batteries (AZMBs) have drawn great attention due to the high theoretical capacity, low redox potential, and abundance reserves. However, the practical application of rechargeable AZMBs are hindered by the poor reversibility of Zn metal anode, owing to easy dendrite growth and serious side reactions. Herein, the preparation of heterogeneous interfacial film with highly dispersed and confined zinc salt in a 2D channel by coassembling polyamide 6, zinc trifluoromethanesulfonate, and layered double hydroxides, which significantly suppresses the dendrite formation, H2 evolution reaction as well as O2 corrosion is reported. The as-developed Zn anodes exhibit a long cycling life up to 1450 h with low reversible deposition potential. Moreover, the assembled Zn||Mn battery delivers a high initial capacity of 321 mAh g-1 and a low capacity decay of ≈0.05% per cycle after 590 cycles, which is promising for high-performance AZMBs. A fluorescent film to realize the in situ observation of the Zn anode during cycling, which provides a new chance for visual observation of the working state of the Zn interface, is also assembled.

Single-Atom Metallophilic Sites for Liquid NaK Alloy Confinement toward Stable Alkali-Metal Anodes.

Room temperature liquid NaK alloy is a promising candidate for high performance metal batteries, due to its dendrite-free property and high energy density. However, its practical application is hindered by the high surface tension of liquid NaK, which causes difficulties in maintaining a stable contact with a current collector. Here, the authors demonstrate the extraordinary stable confinement of NaK alloy at room temperature by constructing a super-wetting substrate, which is based on highly dispersed cobalt-single-atom carbon nanoarrays. The developed liquid anode electrode prevented successfully the leakage of NaK alloy even in harsh stress (>5 MPa) or sharp shock conditions. The symmetric cells achieved ultra-long reversible plating/stripping cycling life in both Na-ion (>1010 hrs) and K-ion electrolytes (>4000 hrs) at 10 mA cm-2 /10 mAh cm-2 . Upon fitting with Na3 V2 (PO4 )3 , the NaK assembled full battery provided high energy density (332.6 kWh kg-1 ) and power density (11.05 kW kg-1 ) with excellent stability after >21600 cycles, which is the best value reported so far. The prepared pouch cell was able to drive a four-axis aircraft, demonstrating a great prospect in practical application. This work offers a new approach in the preparation of advanced dendrite-free liquid metal anodes with promising applications in electrochemical energy storage.

A bifunctional nonenzymatic flexible glucose microsensor based on CoFe-Layered double hydroxide.

A bifunctional flexible glucose microsensor has been successfully fabricated by directly growing a layered double hydroxide nanosheet array (LDH-NSA) on Ni wire. The as-obtained CoFe-LDH-NSA exhibits promising performances in electrochemical and colorimetric detection of glucose with high sensitivity and selectivity. This work demonstrates an effective strategy to fabricate multi-functional glucose nonenzyme sensors.

Electrosynthesis of Well-Defined Metal-Organic Framework Films and the Carbon Nanotube Network Derived from Them toward Electrocatalytic Applications.

An efficient and controllable method to synthesize continuous metal-organic framework (MOF) films is highly desired. Herein, we demonstrate a facile and universal electrochemical method to synthesize homogeneous and uniform zeolitic imidazolate framework (ZIF, a typical class of MOF family) films on various macroconductive substrates (e.g., conductive glass, Ni foam and carbon cloth) as well as nanostructured substrates (one-dimensional nanorod array, two-dimensional nanowall array, and three-dimensional nanoframework). Particularly, the MOF film can be easily transformed into hierarchical ordered carbon nanotube networks, which display multifunctional electrocatalytic performances, such as excellent activity and good long-term stability in overall water splitting and oxygen reduction. It is worth mentioning that this is the first reported work for electrosynthesis of ZIF films on various conductive substrates, illustrating the great potential of the fast and economical method for constructing functional and integrated films or electrodes toward energy-related applications.