Enhancing the Filler Utilization of Composite Gel Electrolytes via In Situ Solution-Processable Method for Sustainable Sodium-Ion Batteries.

The composite gel electrolyte (CGE), which combines the advantages of inorganic solid-state electrolytes and solid polymer electrolytes, is regarded as the ultimate candidate for constructing batteries with high safety and superior electrode-electrolyte interface contact. However, the ubiquitous agglomeration of nanofillers results in low filler utilization, which seriously reduces structural uniformity and ion transport efficiency, thus restricting the development of consistent and durable batteries. Herein, a solution-processable method to in situ construct CGE with high filler utilization is introduced.

Ammonia Electrosynthesis with a Stable Metal-Free 2D Silicon Phosphide Catalyst.

Metal-free 2D phosphorus-based materials are emerging catalysts for ammonia (NH ) production through a sustainable electrochemical nitrogen reduction reaction route under ambient conditions. However, their efficiency and stability remain challenging due to the surface oxidization. Herein, a stable phosphorus-based electrocatalyst, silicon phosphide (SiP), is explored.

Water induced ultrathin MoC nanosheets with high-density grain boundaries for enhanced hydrogen evolution.

Grain boundary controlling is an effective approach for manipulating the electronic structure of electrocatalysts to improve their hydrogen evolution reaction performance. However, probing the direct effect of grain boundaries as highly active catalytic hot spots is very challenging. Herein, we demonstrate a general water-assisted carbothermal reaction strategy for the construction of ultrathin MoC nanosheets with high-density grain boundaries supported on N-doped graphene.

Recent Developments of Cathode Materials for Thermal Batteries.

Big progress has been made in batteries based on an intercalation mechanism in the last 20 years, but limited capacity in batteries hinders their further increase in energy density. The demand for more energy intensity makes research communities turn to conversion-type batteries. Thermal batteries are a special kind of conversion-type battery, which are thermally activated primary batteries composed mainly of cathode, anode, separator (electrolyte), and heating mass.

Atomic-Level Modulation of the Interface Chemistry of Platinum-Nickel Oxide toward Enhanced Hydrogen Electrocatalysis Kinetics.

Precise manipulation of the interactions between different components represents the frontier of heterostructured electrocatalysts and is crucial to understanding the structure-function relationship. Current studies, however, are quite limited. Here, we report targeted modulation of the atomic-level interface chemistry of Pt/NiO heterostructure via an annealing treatment, which results in substantially enhanced hydrogen electrocatalysis kinetics in alkaline media.

Bridging Interparticle Li Conduction in a Soft Ceramic Oxide Electrolyte.

Li-conductive ceramic oxide electrolytes, such as garnet-structured LiLaZrO have been considered as promising candidates for realizing the next-generation solid-state Li-metal batteries with high energy density. Practically, the ceramic pellets sintered at elevated temperatures are often provided with high stiffness yet low fracture toughness, making them too brittle for the manufacture of thin-film electrolytes and strain-involved operation of solid-state batteries. The ceramic powder, though provided with ductility, does not yield satisfactorily high Li conductivity due to poor ion conduction at the boundaries of ceramic particles.

General Design Methodology for Organic Eutectic Electrolytes toward High-Energy-Density Redox Flow Batteries.

By virtue of strong molecular interactions, eutectic electrolytes provide highly concentrated redox-active materials without other auxiliary solvents, hence achieving high volumetric capacities and energy density for redox flow batteries (RFBs). However, it is critical to unveil the underlying mechanism in this system, which will be undoubtedly beneficial for their future research on high-energy storage systems. Herein, a general formation mechanism of organic eutectic electrolytes (OEEs) is developed, and it is found that molecules with specific functional groups such as carbonyl (CO), nitroxyl radical (NO•), and methoxy (OCH ) groups can coordinate with alkali metal fluorinated sulfonylimide salts (especially for bis(trifluoromethanesulfonyl)imide, TFSI), thereby forming OEEs.

Low-Temperature Multielement Fusible Alloy-Based Molten Sodium Batteries for Grid-Scale Energy Storage.

The sustainable future of modern society relies on the development of advanced energy systems. Alkali metals, such as Li, Na, and K, are promising to construct high-energy-density batteries to complement the fast-growing implementation of renewable sources. The stripping/deposition of alkali metals is compromised by serious dendrite growth, which can be intrinsically eliminated by using molten alkali metal anodes.

Gel-Derived Amorphous Bismuth-Nickel Alloy Promotes Electrocatalytic Nitrogen Fixation via Optimizing Nitrogen Adsorption and Activation.

To achieve the electrochemical nitrogen reduction reaction (NRR) for efficient and sustainable NH production, catalysts should exhibit high selectivity and activity with optimal adsorption energy. Herein we developed a three-dimensional (3D) amorphous BiNi alloy toward a significantly enhanced NRR compared with its crystalline and metal counterparts. Ni alloying enables the chemisorption of nitrogen and the lower free-energy change for the *NNH formation, and the 3D alloy electrocatalyst exhibits high catalytic activity for NH production with a yield rate of 17.

Understanding Charge Storage in Hydrated Layered Solids MOPO (M = V, Nb) with Tunable Interlayer Chemistry.

Hydrated layered solids are interesting charge storage hosts with potentially high electrochemical activity and interlayer tunability. Although it is often possible to tune their interlayer distance by a pillaring strategy, the poor electrochemical stability of such artificial structures remains a major issue in device operation. Here we investigate the charge storage properties of MOPO (M = V, Nb) hydrates with a nanosheet morphology to understand the influence of the interlayer environment on cycling stability, as well as ion selectivity.

Molecular Engineering of Azobenzene-Based Anolytes Towards High-Capacity Aqueous Redox Flow Batteries.

Aqueous redox flow batteries (RFBs) are promising alternatives for large-scale energy storage. However, new organic redox-active molecules with good chemical stability and high solubility are still desired for high-performance aqueous RFBs due to their low crossover capability and high abundance. We report azobenzene-based molecules with hydrophilic groups as new active materials for aqueous RFBs by utilizing the reversible redox activity of azo groups.

Reversible redox chemistry in azobenzene-based organic molecules for high-capacity and long-life nonaqueous redox flow batteries.

Redox-active organic molecules have drawn extensive interests in redox flow batteries (RFBs) as promising active materials, but employing them in nonaqueous systems is far limited in terms of useable capacity and cycling stability. Here we introduce azobenzene-based organic compounds as new active materials to realize high-performance nonaqueous RFBs with long cycling life and high capacity. It is capable to achieve a stable long cycling with a low capacity decay of 0.

Room-Temperature All-Liquid-Metal Batteries Based on Fusible Alloys with Regulated Interfacial Chemistry and Wetting.

Liquid metal batteries are regarded as potential electrochemical systems for stationary energy storage. Currently, all reported liquid metal batteries need to be operated at temperatures above 240 °C to maintain the metallic electrodes in a molten state. Here, an unprecedented room-temperature liquid metal battery employing a sodium-potassium (Na-K) alloy anode and gallium (Ga)-based alloy cathodes is demonstrated.

O-coordinated W-Mo dual-atom catalyst for pH-universal electrocatalytic hydrogen evolution.

Single-atom catalysts (SACs) maximize the utility efficiency of metal atoms and offer great potential for hydrogen evolution reaction (HER). Bimetal atom catalysts are an appealing strategy in virtue of the synergistic interaction of neighboring metal atoms, which can further improve the intrinsic HER activity beyond SACs. However, the rational design of these systems remains conceptually challenging and requires in-depth research both experimentally and theoretically.

Multifunctional Active-Center-Transferable Platinum/Lithium Cobalt Oxide Heterostructured Electrocatalysts towards Superior Water Splitting.

Designing cost-effective and efficient electrocatalysts plays a pivotal role in advancing the development of electrochemical water splitting for hydrogen generation. Herein, multifunctional active-center-transferable heterostructured electrocatalysts, platinum/lithium cobalt oxide (Pt/LiCoO ) composites with Pt nanoparticles (Pt NPs) anchored on LiCoO nanosheets, are designed towards highly efficient water splitting. In this electrocatalyst system, the active center can be alternatively switched between Pt species and LiCoO for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively.

In Situ Formation of Liquid Metals via Galvanic Replacement Reaction to Build Dendrite-Free Alkali-Metal-Ion Batteries.

Galvanic replacement reactions have been studied as a versatile route to synthesize nanostructured alloys. However, the galvanic replacement chemistry of alkali metals has rarely been explored. A protective interphase layer will be formed outside templates when the redox potential exceeds the potential windows of nonaqueous solutions, and the complex interfacial chemistry remains elusive.

Enhanced Surface Interactions Enable Fast Li Conduction in Oxide/Polymer Composite Electrolyte.

Li -conducting oxides are considered better ceramic fillers than Li -insulating oxides for improving Li conductivity in composite polymer electrolytes owing to their ability to conduct Li through the ceramic oxide as well as across the oxide/polymer interface. Here we use two Li -insulating oxides (fluorite Gd Ce O and perovskite La Sr Ga Mg O ) with a high concentration of oxygen vacancies to demonstrate two oxide/poly(ethylene oxide) (PEO)-based polymer composite electrolytes, each with a Li conductivity above 10  S cm at 30 °C. Li solid-state NMR results show an increase in Li ions (>10 %) occupying the more mobile A2 environment in the composite electrolytes.

New insights into the effect of pH on the mechanism of ofloxacin electrochemical detection in aqueous solution.

Antibiotic contamination in water has become an increasingly serious problem that poses a potentially huge threat to human health. Ofloxacin (OFL) is a typical broad-spectrum quinolone antibiotic and is frequently detected in a wide variety of aquatic environments. Given its frequent contamination, the need for new electrochemical sensors to quickly and efficiently detect OFL in aquatic environments has attracted increasing attention.

Biredox Eutectic Electrolytes Derived from Organic Redox-Active Molecules: High-Energy Storage Systems.

One promising candidate for high-energy storage systems is the nonaqueous redox flow battery (NARFB). However, their application is limited by low solubility of redox-active materials and poor performance at high current density. Reported here is a new strategy, a biredox eutectic, as the sole electrolyte for NARFB to achieve a significantly higher concentration of redox-active materials and enhance the cell performance.

A Liquid-Metal-Enabled Versatile Organic Alkali-Ion Battery.

Despite the high specific capacity and low redox potential of alkali metals, their practical application as anodes is still limited by the inherent dendrite-growth problem. The fusible sodium-potassium (Na-K) liquid metal alloy is an alternative that detours this drawback, but the fundamental understanding of charge transport in this binary electroactive alloy anode remains elusive. Here, comprehensive characterization, accompanied with density function theory (DFT) calculations, jointly expound the Na-K anode-based battery working mechanism.

High-Performance P2-NaMnCoZrO Cathode for Sodium-Ion Batteries.

Room-temperature sodium-ion batteries (NIBs) using a manganese-based layered cathode have been considered promising candidates for grid-scale energy storage applications. However, manganese-based materials suffer from serious Jahn-Teller distortion, phase transition, and unstable interface, resulting in severe structure degradation, sluggish sodium diffusion kinetics, and poor cycle, respectively. Herein, we demonstrate a Zr-doped NaMnCoZrO material with much improved specific capacity and rate capability compared with Zr-free NaMnCoO when used as cathode materials for NIBs.

Advanced Fuel Cell Based on Perovskite La-SrTiO Semiconductor as the Electrolyte with Superoxide-Ion Conduction.

A solid oxide fuel cell's performance is largely determined by the ionic-conducting electrolyte. A novel approach is presented for using the semiconductor perovskite LaSrTiO (LST) as the electrolyte by creating surface superionic conduction, and the authors show that the LST electrolyte can deliver superior power density, 908.2 mW cm at just 550 °C.

Solvent-Dependent Intercalation and Molecular Configurations in Metallocene-Layered Crystal Superlattices.

Organic-inorganic superlattices are a class of artificial structures of significant scientific and technological importance. Forming these hybrid materials can be achieved via controlled intercalation of organic molecules into inorganic layered hosts, which is a complex course involving multiple physicochemical processes. In solution phase, it is further complicated by interaction of solvent molecules with the intercalant and/or host.

Defect Engineering Metal-Free Polymeric Carbon Nitride Electrocatalyst for Effective Nitrogen Fixation under Ambient Conditions.

Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions provides an intriguing picture for the conversion of N into NH . However, electrocatalytic NRR mainly relies on metal-based catalysts, and it remains a grand challenge in enabling effective N activation on metal-free catalysts. Here we report a defect engineering strategy to realize effective NRR performance (NH yield: 8.

TiO-Photoanode-Assisted Direct-Solar-Energy Harvesting and Storage in a Solar-Powered Redox Cell Using Halides as Active Materials.

The rapid deployment of renewable energy is resulting in significant energy security, climate change mitigation, and economic benefits. We demonstrate here the direct solar-energy harvesting and storage in a rechargeable solar-powered redox cell, which can be charged solely by solar irradiation. The cell follows a conventional redox-flow cell design with one integrated TiO photoanode in the cathode side.