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Sodium metal batteries have emerged as potential rivals to lithium‐ion batteries. Nevertheless, maintaining a stable sodium metal anode under harsh conditions (current density >10 mA cm−2) is extremely challenging. The primary issue is the highly reactive sodium metal continuously reacts with the electrolyte to form a thick and loose solid electrolyte film. The tip effect causes sodium ions (Na+) accumulated in the bulge resulting in uneven deposition. In this paper, a unique artificial interfacial layer (Ag nanoparticles distributed in NaClO4‐based matrix) is prepared on the surface of a metallic sodium anode using in situ displacement reaction. Ag particles arranged at the bottom of the artificial layer act as effective nucleation sites helping Na+ deposit uniformly, while the built‐in electric field formed between Ag in the middle/top of the artificial layer and the sodium accelerates the migration of Na+ in the interfacial layer during the deposition and reduce the polarization. Such important properties further allow the steady operation of modified sodium metal batteries in very harsh conditions. The symmetric battery achieves reversible stripping/plating for over 1000 h under high current density (10 mA cm−2). Moreover, the full cell coupled with a high‐loading Na3V2(PO4)3 cathode (20 mg cm−2) presents a stable cycle performance. [ABSTRACT FROM AUTHOR]

Composite gel polymer electrolyte (CGPE), derived from ceramic fillers has emerged as one of the most promising candidates to improve the safety and cycling stability of lithium metal batteries. However, the poor interface compatibility between the ceramic phase and polymer phase in CGPE severely deteriorates lithium‐ion pathways and cell performances. In this work, a fluorescent ceramic nanowire network that can palliate the energy barrier of photoinitiators and contribute to preferential nucleation and growth of polymer monomers is developed, thus inducing polymer segment orderly arrangement and tightly combination. A proof‐of‐concept study lies on fabrications of poly(ethylene oxide) closely coating on the ceramic nanowires, thus dividing the matrix into mesh units that contribute to directional lithium‐ion flux and dendrite‐free deposition on the metallic anode. The CGPE, based on the state‐of‐the‐art self‐luminous framework, facilitates high‐performance quasi‐solid‐state Li||LiFePO4 cell, registering a high capacity of 143.3 mAh g−1 after 120 cycles at a mass loading of 12 mg cm−2. X‐ray computed tomography provides an insight into the relationship between directional lithium‐ion diffusion and lithium deposition behavior over the electrochemical processes. The results open a door to improve the electrochemical performances of composite electrolytes in various applications. [ABSTRACT FROM AUTHOR]

Electrolyte solvent, salt, and additive directly determine many battery indicators such as voltage limit, safe reliability, and temperature limit. In Ca‐metal batteries, suitable electrolyte and interphase are necessary to achieve reversible calcium plating/stripping, which is challenging for F‐based salts at room temperature. Ion transport and charge transfer in calcium batteries with Ca(BF4)2‐NaPF6 electrolyte are regulated for the first time by altering solvent and salt categories and ratios, achieving adjustable interphase species and microstructure, calcium deposition/dissolution overpotentials, and cycling stability. The optimized electrolyte of 0.1 m Ca(BF4)2‐0.9 m NaPF6 in ethylene carbonate/diethyl carbonate/dimethyl carbonate/ethyl methyl carbonate (7:1:6:6, v/v) contributes to the most stable Ca plating/stripping cycling and the weakest overpotential, as well as Na/Ca‐based hybrid solid electrolyte interphases including proper amount of organic matter. Ca‐metal batteries with the optimized electrolyte achieve an ultrahigh reversible capacity of ≈290 mAh g−1 (at 200 mA g−1 and 1.2–4.5 V), almost four times more than that of counterpart ones (≈65 mAh g−1), equivalent to energy/power performance of ≈616 Wh kg−1 at 429 W kg−1 among the best ones for multivalent ion rechargeable metal batteries. [ABSTRACT FROM AUTHOR]

Abstract Rechargeable aqueous zinc-ion batteries (ZIBs) are very promising energy storage systems owing to their low cost, high reliability, and high volumetric energy density; however, the stiff challenge for the progress of ZIBs is the lack of suitable materials that permit divalent ion-intercalation/deintercalation with fast kinetics, long cycling durations, and high rate capabilities. Herein, we demonstrate V 10 O 24 ·12H 2 O dendrites with a large interlayer spacing of 1.4 nm, fabricated through a simple hydrothermal method. The unique, open, and stable structure complemented by a mixed valence enables a satisfactory battery performance: a specific capacity of 164.5 mAh g−1, long-term cycling stability of 80.1% capacity retention after 3000 cycles, and high power density of 12247.8 W kg−1 at a high energy density of 88.5 Wh kg−1. This study provides a viable and attractive cathode material for practical ZIBs. [ABSTRACT FROM AUTHOR]

The table of contents: We propose a facile strategy to design a flexible trifunctional electrode by directly growing N, Co dual-doped carbon nanotube (N, Co-CNT) on carbon cloth substrate. The obtained electrode with excellent activity and desired stability can fulfill efficient water splitting device, highly bendable zinc-air batteries, and an integrative power-to-gas system. • A simple strategy was developed to synthesis N and Co co-doped carbon nanotube (N, Co-CNT) films on flexible carbon cloth. • Removing cobalt cores of cobalt carbon core-shell structure does not result in the degeneration of trifunctional activity. • Flexible Zn-air battery assembled by N, Co-CNT displayed excellent battery performance and hold superb flexibility. • An electrolyzer powered by flexible zinc-air batteries system was successfully conducted to effectively catalyze the water. Developing effective and stable electrodes with foldable features to promote hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction are vital for fully realizing future flexible energy devices. However, combining three active composites into a single foldable electrode is still a challenge. Thereby, this work successfully fabricates a flexible trifunctional electrode based on self-supported N, Co co-doped carbon nanotubes (N, Co-CNTs). The obtained N, Co-CNTs possess favorable component-structure features, including heteroatom-doped structure and rich N content, which can simultaneously boost three crucial reactions. According to acid-washed experiment, the metallic cobalt cores are not directly attributed to catalytic activity. Moreover, As-assembled flexible zinc-air battery (ZAB) provides a high peak power density (114 mW cm−2) and long-term durability. Specially, this flexible ZAB reliably operates under external mechanical changes and an as-constructed water electrolyzer can be powered by two flexible ZABs in series. [ABSTRACT FROM AUTHOR]

The in-situ fabrication of nanomaterials on conductive substrate is regarded as a viable way to prepare high-performance energy-storage materials, which not only can save the tedious production processes but also eliminate the binders and conductive agents. In this work, homogeneous vertically-aligned VO 2 nanobelt arrays growing directly on the vanadium foil are prepared via a facile hydrothermal method. Thanks to the unique nanoarrays structure in shortening ion diffusion path and providing ample space for infiltration of electrolyte, the nanobelt arrays demonstrate good electrochemical performance in alkali metal ion batteries. When employed as cathode for Li-ion batteries, a reversible specific capacity of 444.2 mAh g−1 at 50 mA g−1 and stable cyclic life over 900 cycles (lasting over 3120 h) with 83.9% capacity retention are successfully achieved. Furthermore, the VO 2 arrays also exhibit an acceptable Na+-storage property and maintain good structure integrity upon cycling. [ABSTRACT FROM AUTHOR]

Aqueous zinc‐ion batteries (AZIBs), which are low‐cost and environmentally friendly, have been regarded feasible for large‐scale energy storage. But the widespread application of AZIBs is hindered by lack of suitable cathode materials with high capacity and long cycle life. The zinc‐storage mechanisms, especially the formation of basic zinc salt (BZS), are still unclear. Here, Ag2V4O11 is developed as a cathode material for AZIBs, which delivers a specific capacity of 213 mA h g−1 and excellent cycling performance (93% capacity retention after 6000 cycles). The reversible formation/decomposition of BZS and reduction/oxidation of metallic Ag are ascertained during the insertion/extraction of Zn(H2O)62+. Remarkably, the phase composition of BZS in Zn(CF3SO3)2‐based electrolyte is identified first. The role of in situ formed Ag nanoparticles is simulated by employing the commercial Ag nanoparticles as an additive into the V2O5‐based electrodes. The introduction of Ag significantly improves the specific capacity (at least 50% improvement) and accordingly it is proposed that the pseudo‐Zn–air reaction (oxygen reduction reaction‐like redox reaction happens on material surface in a closed system) promotes the electrochemical performance of Ag2V4O11. This work reveals the BZS rather than unknown new phases on the electrode surface and puts forward a possible way in raising electrochemical properties by utilizing the pseudo‐Zn–air reaction. [ABSTRACT FROM AUTHOR]