Manipulating Zn Metal Texture with Guided Zincophilic Sites via Electrochemical Stripping for Dendrite-Free Zn Anodes.

Constructing a three-dimensional (3D) structure along with Zn (002) texture selective exposure is a promising strategy to tackle the issues faced by Zn metal anodes. Herein, for the first time, we proposed an electrochemical stripping strategy to achieve controlled modification of the texture and microstructure of zinc foils in one step, building a hierarchical structure with (002) texture preferred exposed Zn (SZ). The SZ with favorable zincophilic properties not only can reduce the concentration polarization at the interface but also allow Zn to grow horizontally on the edge of the (002) texture by guiding the adsorption sites for Zn2+. Moreover, the honeycomb-like structure is beneficial to rearrange the distribution of the Zn2+ flux as well as alleviating stress changes during cycling. Thus, the SZ||Cu cell exhibits excellent stability with a Coulombic efficiency of 99.76% over 1800 cycles. The SZ||NaV3O8·xH2O cell with inconspicuous self-discharge effect maintains a high areal capacity of 3.67 mA h cm-2 even after 700 cycles with a low N/P ratio of 3.6. This work achieves texture architecture and structure designing on Zn foils simultaneously by metallurgical electrochemical methods and opens up a potential strategy to implement the practicality of zinc metal anodes.

Engineering a Ni-Al Brucite-Based Interface Layer with Regulated Zn2+ Flux for Highly Reversible Zn Metal Anodes.

Practical aqueous Zn-ion batteries are appealing for grid-scale energy storage with intrinsic safety and cost-effectiveness, yet their cycling stability and reversibility are limited by unwanted dendrite growth and water-induced erosions on Zn. Herein, a hydrophilic and Zn2+-conductive Ni-Al layered double hydroxide (NiAl-LDH) interphase layer is constructed on the surface of Zn, in which NiAl-LDH enables a more uniformly distributed Zn2+ concentration and interfacial electric field owing to its large internal Zn2+ channels and favorable charge redistribution effect. Consequently, the NiAl-LDH-integrated Zn anode achieves low voltage hysteresis and high reversibility of Zn plating/stripping with uniform underneath deposition behaviors. Remarkably, the resultant NiAl-2 LDH@Zn delivers superior cycling durability over 2800 h (∼4 months, 0.5 mA cm-2), realizes high reversibility with 99.4% average Coulombic efficiency over 1400 cycles, and confers stable operation of full Zn cells with high V2O5 mass loadings. This work offers a facile and instructive interface design approach for achieving highly stable Zn metal anodes.

Building Negative-Thermal-Expansion Protective Layers on the Grain Boundary of Ni-rich Cathodes Enables Safe and Durable High Voltage Lithium-Ion Batteries.

Ni-rich layered oxide cathode materials demonstrate high energy densities for Li-ion batteries, but the electrochemically driven thermal runaway and mechanical degradation remain their long-standing challenges in practical applications. Herein, it presents a novel ZrV2 O7  (ZVO) coating with negative thermal expansion properties along the secondary particles and primary particle grain boundaries (GBs), to simultaneously enhance the structural and thermal stability of LiNi0.8 Co0.1 Mn0.1 O2 (NCM811). It unveils that, such an architecture can significantly enhance the electronic conductivity, suppress the microcracks of GBs, alleviate the layered to spinel/rock-salt phase transformation, and meanwhile relieve the lattice oxygen loss by increasing the oxygen vacancy formation energy increased (1.43 vs 1.90 eV). Consequently, the ZVO-coated NCM811 material demonstrates a remarkable cyclability with 86.5% capacity retention after 100 cycles, and an outstanding rate performance of 30 C under a high-voltage of 4.6 V, outperforming the state-of-the-art literature. More importantly, the Li+ transportation can be readily blocked at 120 °C by the negative-thermal-expansion ZVO coating, thus avoiding the high-temperature thermal runaway.

Design Strategies toward High-Performance Zn Metal Anode.

Rechargeable aqueous Zn-ion batteries (AZIBs) are one of the most promising alternatives for traditional energy-storage devices because of their low cost, abundant resources, environmental friendliness, and inherent safety. However, several detrimental issues with Zn metal anodes including Zn dendrite formation, hydrogen evolution, corrosion and passivation, should be considered when designing advanced AZIBs. Moreover, these thorny issues are not independent but mutually reinforcing, covering many technical and processing parameters. Therefore, it is necessary to comprehensively summarize the issues facing Zn anodes and the corresponding strategies to develop roadmaps for the development of high-performance Zn anodes. Herein, the failure mechanisms of Zn anodes and their corresponding impacts are outlined. Recent progress on improving the stability of Zn anode is summarized, including structurally designed Zn anodes, Zn alloy anodes, surface modification, electrolyte optimization, and separator design. Finally, this review provides brilliant and insightful perspectives for stable Zn metal anodes and promotes the large-scale application of AZIBs in power grid systems.

Water interaction with B-site (B = Al, Zr, Nb, and W) doped SrFeO3-δ-based perovskite surfaces for thermochemical water splitting applications.

Density functional theory (DFT) calculations were performed to study the interaction of water with the SrO and FeO2 terminations of the SrFeO3-δ (001) surface, where the effects of the metal dopants (Al, Zr, Nb, and W), surface oxygen vacancies, and oxygen ion migration were investigated. Our calculations showed that the metal dopants benefited the molecular and dissociative adsorptions of H2O on both the perfect and oxygen-vacancy-containing surfaces. The surface oxygen vacancies were predicted to promote the dissociative adsorption of H2O and the formation of H2. For all structures studied, H2 release was found to be always an overall endothermic process, except for the W-doped structure which will become exothermic at high temperature. On the oxygen-vacancy-containing surface, H2 generation was predicted to be easier at the SrO termination than the FeO2 termination. Furthermore, we also investigated the oxygen ion migration mechanism on all surface structures, predicted the behaviour of oxygen migration and the effect of oxygen vacancy defects. Our results showed that Al doping facilitated not only the formation of surface oxygen vacancies, but also oxygen migration from the surface to the subsurface, in contrast to the Zr, Nb and W-doped structures. This study provided significant insights into the interaction of water with the surfaces of doped SrFeO3-δ perovskite materials for thermochemical water splitting applications.

Proton Storage in Metallic H1.75MoO3 Nanobelts through the Grotthuss Mechanism.

The proton, as the cationic form of the lightest element-H, is regarded as most ideal charge carrier in "rocking chair" batteries. However, current research on proton batteries is still at its infancy, and they usually deliver low capacity and suffer from severe acidic corrosion. Herein, electrochemically activated metallic H1.75MoO3 nanobelts are developed as a stable electrode for proton storage. The electrochemically pre-intercalated protons not only bond directly with the terminal O3 site via strong O-H bonds but also interact with the oxygens within the adjacent layers through hydrogen bonding, forming a hydrogen-bonding network in H1.75MoO3 nanobelts and enabling a diffusion-free Grotthuss mechanism as a result of its ultralow activation energy of ∼0.02 eV. To the best of our knowledge, this is the first reported inorganic electrode exhibiting Grotthuss mechanism-based proton storage. Additionally, the proton intercalation into MoO3 with formation of H1.75MoO3 induces strong Jahn-Teller electron-phonon coupling, rendering a metallic state. As a consequence, the H1.75MoO3 shows an outstanding fast charging performance and maintains a capacity of 111 mAh/g at 2500 C, largely outperforming the state-of-art battery electrodes. More importantly, a symmetric proton ion full cell based on H1.75MoO3 was assembled and delivered an energy density of 14.7 Wh/kg at an ultrahigh power density of 12.7 kW/kg, which outperforms those of fast charging supercapacitors and lead-acid batteries.

A Comprehensive Understanding of Interlayer Engineering in Layered Manganese and Vanadium Cathodes for Aqueous Zn-Ion Batteries.

Rechargeable aqueous zinc-ion batteries (AZIBs) hold a budding technology for large-scale stationary energy storage devices due to their inherent safety, cost-effectiveness, eco-friendliness, and acceptable electrochemical performance. However, developing a cathode material with fast kinetics and durable structural stability for Zn2+ intercalation is still an arduous challenge. Compared with other cathode materials, layered manganese/vanadium (Mn/V) oxides that feature merits of adjustable interlayer spacing and considerable specific capacity have attracted much interest in AZIBs. However, the intrinsic sluggish reaction kinetics, inferior electrical conductivity, and notorious dissolution of active materials still obstruct the realization of their full potentials. Interlayer engineering of pre-intercalation is regarded as an effective solution to overcome these problems. In this review, we start from the crystal structure and reaction mechanism of layered Mn/V oxide cathodes to critical issues and recent progress in interlayer engineering. Finally, some future perspectives are outlined for the development of high-performance AZIBs.

Architecting a Hydrated Ca0.24V2O5 Cathode with a Facile Desolvation Interface for Superior-Performance Aqueous Zinc Ion Batteries.

Vanadium-based materials are promising cathode candidates for low-cost and high-safety aqueous zinc-ion batteries (AZIBs). However, they suffer from inferior rate capability and undesirable capacity fading due to their intrinsic poor conductivity and structural instability. Herein, we synthesize hydrated Ca0.24V2O5·0.75H2O (CaVOH) nanoribbons with in situ incorporations of the carbon nanotubes via a one-step hydrothermal method, achieving an integrated architecture hybrid cathode (C/CaVOH) design. Benefitting from the robust structure and low desolvation interface, the prefabricated C/CaVOH cathodes deliver a high capacity of 384.2 mA h g-1 at 0.5 A g-1 with only 5.6% capacity decay over 300 cycles, enable an ultralong cycling life of 10,000 cycles at 20.0 A g-1 with 80.2% capacity retention, and exhibit an impressive rate capability (165 mA h g-1 at 40.0 A g-1) with a high mass loading of ∼4 mg cm-2. Moreover, through the theoretical calculations and a series of ex situ characterizations, we demonstrate the Zn2+/H+ co-intercalation storage mechanism, the key role of the gallery water, and the function of the induced C-O groups in promoting kinetics of the C/CaVOH electrode. This work highlights the strategy of in situ implanted high conductivity materials to engineer vanadium-based or other cathodes for high-performance AZIBs.

Tremella-like Hydrated Vanadium Oxide Cathode with an Architectural Design Strategy toward Ultralong Lifespan Aqueous Zinc-Ion Batteries.

Rechargeable aqueous zinc-ion batteries (ZIBs) are promising systems for energy storage due to their operational safety, low cost, and environmental friendliness. However, the development of suitable cathode materials is plagued by the sluggish dynamics of Zn2+ with strong electrostatic interaction. Herein, an Al3+-doped tremella-like layered Al0.15V2O5·1.01H2O (A-VOH) cathode material with a large pore diameter and high specific surface area is demonstrated to greatly boost electrochemical performance as ZIB cathodes. Resultant ZIBs with a 3 M Zn(CF3SO3)2 electrolyte deliver a high specific discharge capacity of 510.5 mAh g-1 (0.05 A g-1), and an excellent energy storage performance is well maintained with a specific capacity of 144 mAh g-1 (10 A g-1) even after ultralong 10,000 cycles. The decent electrochemical performance roots in the novel tremella-like structure and the interlayer of Al3+ ions and water molecules, which could improve the electrochemical reaction kinetics and structural long cycle stability. Furthermore, the assembled coin-type cells could power a light-emitting diode (LED) lamp for 2 days. We believed that the design philosophy of unique morphology with abundant active sites for Zn2+ storage will boost the development of competitive cathodes for high-performance aqueous batteries.

Efficient Synchronous Extraction of Nickel, Copper, and Cobalt from Low-Nickel Matte by Sulfation Roasting‒Water Leaching Process.

Considering that the low recovery efficiency and the massive loss of valuable metals by the traditional pyrometallurgical process smelting low‒nickel matte. Therefore, this paper focuses on studying the optimal process parameters and the mechanism of sulphation roasting followed by water leaching achieving efficient synchronous extraction of nickel (Ni), copper (Cu), and cobalt (Co) from low‒nickel matte with sodium sulfate as the sulfating addictive. Under optimal conditions, the recovery efficiency of Ni, Cu, and Co metals can achieve 95%, 99%, and 94%, respectively, whereas the recovery efficiency of Fe metal is less than 1%. The results revealed that the mechanism of the sulfating roasting pretreatment could form a liquidus eutectic compound sulfates [Na2Me(SO4)2] (Me = Ni, Cu, Co) at the solid-solid interface, which plays a significant role in promoting the leaching efficiency of valuable metals. Not only enhance the reaction kinetics of sulfation, but improve the utilization efficiency of SO2/SO3. Thus, the sulfation roasting‒water leaching process developing an efficient and eco-friendly pathway to simultaneous extraction of Ni, Cu, and Co valuable metals from low grade sulfide ores.