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Li and Zn metal batteries are the most promising candidates to replace conventional Li-ion batteries. However, a series of issues, especially dendrites caused by uneven deposition of cations during charge-discharge cycles, hinder their practical application. Here, we proposed a facile separator modification method which combines physical and chemical forces to regulate uniform and rapid deposition of both Li

Energy storage materials 50, 464 - 472 (2022). doi:10.1016/j.ensm.2022.05.048, A cathode/anode compatible aqueous zinc triflate electrolyte is proposed by reorganizing the solvation structure of the electrolyte using an acetonitrile co-solvent. Acetonitrile notably alters the hydrogen bonds of the electrolyte, reducing the activity of water. Using this electrolyte, a ZnǁV2O5 full-cell exhibits high Coulombic efficiency, long cycle life and high rate capability. The interactions between electrolyte, cathode and Zn anode are clarified based on comprehensive in operando and ex situ experiments and molecular dynamics simulations. The addition of acetonitrile does not change the bulk ion storage of V2O5, but the unique electrode-electrolyte interfacial films with specific compositions and spatial distribution protect the Zn and V2O5 electrodes and improve the interfacial kinetics of the electrodes, thus significantly promoting the cycling performance of the full cell. This cathode/anode compatible electrolyte can overcome the challenges of both the cathode and anode which would promote aqueous rechargeable zinc batteries into practical application., Published by Elsevier, Amsterdam

Aqueous zinc energy storage devices, holding various merits such as high specific capacity and low costs, have attracted extensive attention in recent years. Nevertheless, Zn metal anodes still suffer from a short lifespan and low Coulombic efficiency due to corrosion and side reactions in aqueous electrolytes. In this paper, we construct an artificial Sn inorganic layer on Zn metal anode through a facile strategy of atoms exchange. The Sn layer suppresses Zn dendrite growth by facilitating homogeneous Zn plating and stripping during charge and discharge processes. Meanwhile, the Sn protective layer also serves as a physical barrier to decrease Zn corrosion and hydrogen generation. As a result, The Sn-coated anode (Sn|Zn) exhibits a low polarization voltage (∼34 mV at 0.5 mAh/cm2) after 800 testing hours and displays a smooth and an even surface without corrosion. Moreover, the zinc ion capacitor (Sn|Zn|| activated carbon) is assembled with an enhanced capacity of 42 mAh/g and a capacity retention of 95% after 10000 cycles at 5 A/g. This work demonstrates a feasible approach for the commercialization of aqueous Zn-based energy storage devices.

A fundamental understanding of the nucleation and growth behaviors of Zn metal anodes over a wide range of temperatures is of great value for suppressing Zn dendrite growth. However, work focused on the early nucleation and growth behavior of Zn metal at various temperatures is still absent. Here, we study the effect of cycling temperature on Zn nuclei size and areal density and find that low temperature induces a smaller and dense nucleus, which prevents the formation of dendrites. Based on this finding, a cooling-treatment-based self-healing strategy is developed to in situ eliminate dendrites, which effectively prolongs the lifespan of the Zn anode by 520%. This novel self-healing strategy could be employed as a reliable strategy for restoring batteries in situ to reach a longer lifespan.

Dendrite growth and side reactions of Zn metal anodes remain unresolved obstacles for practical application of aqueous Zn ion batteries. Herein, a two-dimensional (2D) organic-inorganic heterostructure with controlled thickness was constructed as a protective layer for a Zn metal anode. The reduction of uniformly distributed polyoxometalate in the layer causes a negative charge density gradient, which can accelerate zinc ion transfer, homogenize zinc deposition, and shield sulfates at the electrode interface, while the exposed hydrophobic alkyl chain of the layer can isolate the direct contact of water with the Zn anode. As a result of the synergetic effect, this 2D organic-inorganic heterostructure enables high Zn plating/stripping reversibility, with high average Coulombic efficiencies of 99.97% for 3700 cycles at 2 mA cm(-2). Under high Zn utilization conditions, a high areal-capacity full cell with hundreds of cycles was demonstrated.

Aqueous zinc metal batteries with mild acidic electrolytes are considered promising candidates for large-scale energy storage. However, the Zn anode suffers from severe Zn dendrite growth and side reactions due to the unstable interfacial pH and the absence of a solid electrolyte interphase (SEI) protective layer. Herein, a novel and simple mixed electrolyte strategy is proposed to address these problems. The mixed electrolytes of 2 M ZnSO

Two-dimensional transition metal dichalcogenides are promising anode materials for Na ion batteries (NIBs). In this study, we carried out a comprehensive investigation to analyze the structural, electrochemical characteristics, and diffusion kinetics of bulk WX

Fe/Co-based diatomic catalysts decorated on an N-doped graphene substrate are investigated by first-principles calculations to improve the electrochemical properties of Li–S batteries. Our results demonstrate that FeCoN8@Gra not only possesses moderate adsorption energies towards Li2S n species, but also exhibits superior catalytic activity for both reduction and oxidation reactions of the sulfur cathode. Moreover, the metallic property of the diatomic catalysts can be well maintained after Li2S n adsorption, which could help the sulfur cathode to maintain high conductivity during the whole charge–discharge process. Given these exceptional properties, it is expected that FeCoN8@Gra could be a promising diatomic catalyst for Li–S batteries and afford insights for further development of advanced Li–S batteries.

Advanced functional materials 32(16), 2110674 (2022). doi:10.1002/adfm.202110674, Herein, an eco-friendly and high safety aqueous Mg-ion electrolyte (AME) with a wide electrochemical stability window (ESW) $≈$ 3.7 V, containing polyethylene glycol (PEG) and low-concentration salt (0.8 m Mg(TFSI)$_2$), is proposed by solvation structure reorganization of AME. The PEG agent significantly alters the Mg$^{2+}$ solvation and hydrogen bonds network of AMEs and forms the direct coordination of Mg$^{2+}$ and TFSI-, thus enhancing the physicochemical and electrochemical properties of electrolytes. As an exemplary material, V$_2$O$_5$ nanowires are tested in this new AME and exhibit initial high discharge/charge capacity of 359/326 mAh g$^{-1}$ and high capacity retention of 80% after 100 cycles. The high crystalline $α$-V$_2$O$_5$ shows two 2-phase transition processes with the formation of $ε$-Mg$_{0.6}$V$_2$O$_5$ and Mg-rich Mg$_x$V$_2$O$_5$ (x $≈$1.0) during the first discharge. Mg-rich Mg$_x$V$_2$O$_5$ (x $≈$ 1.0) phase formed through electrochemical Mg-ion intercalation at room temperature is for the first time observed via XRD. Meanwhile, the cathode electrolyte interphase (CEI) in aqueous Mg-ion batteries is revealed for the first time. MgF$_2$ originating from the decomposition of TFSI- is identified as the dominant component. This work offers a new approach for designing high-safety, low-cost, eco-friendly, and large ESW electrolytes for practical and novel aqueous multivalent batteries., Published by Wiley-VCH, Weinheim