Lithiophilic Chemistry Facilitated Ultrathin Lithium for Scalable Prelithiation.

Prelithiation plays a crucial role in advancing the development of high-energy-density batteries, and ultrathin lithium (UTL) has been proven to be a promising anode prelithiation reagent. However, there remains a need to explore an adjustable, efficient, and cost-effective method for manufacturing UTL. In this study, we introduce a method for producing UTL with adjustable thicknesses ranging from 1.5 to 10 µm through blade coating of molten lithium on poly(vinylidene fluoride)-modified copper current collectors. By employing the transfer-printing method, prelithiated graphite and Si-C composite electrodes are prepared, which exhibit significantly improved initial Coulombic efficiencies of 99.60% and 99.32% in half-cells, respectively. Moreover, the energy densities of Li(NiCoMn)1/3O2 and LiFePO4 full cells assembled with the prelithiated graphite electrodes increase by 13.1% and 23.6%, respectively.

High-Performance Hydrogen Evolution Reaction Catalytic Electrodes by Liquid Joule-Heating Growth.

Despite the great progress in the research of integrated catalytic electrodes for hydrogen evolution reaction, the efficient preparation of high-performance catalytic electrodes with high current density remains a challenging issue. In this work, a metal (Pt)-amorphous oxide (NiO) heterostructure catalyst is successfully in situ grown on nickel foam using liquid Joule-heating. Based on the superhydrophilic surface of the electrode and its superior mechanical and chemical stability, the catalytic electrode exhibits excellent catalytic performance in alkaline electrolytes with only 100 mV overpotential to achieve 5000 mA cm-2 current density and maintains a stable performance of 500 h under a fixed current density of 1000 mA cm-2 . Further verification of the practical application of the Pt@NiO-Ni electrode in the alkaline electrolyzer is conducted. The results show that the alkaline water electrolyzer with NiFe layered double hydroxide as the anode and Pt@NiO-Ni as the cathode exhibits superior performance than the previously reported electrolyzers, with a current density of 1 A cm-2 already achieved at 1.75 V, which is even comparable to some anion exchange membrane water electrolyzers. These experimental results illustrate the strong applicability of Pt@NiO-Ni electrode at industrial scale current densities.

Cable-Car Electrocatalysis to Drive Fully Decoupled Water Splitting.

The increasing demand for clean energy conversion and storage has increased interest in hydrogen production via electrolytic water splitting. However, the simultaneous production of hydrogen and oxygen in this process poses a challenge in extracting pure hydrogen without using ionic conducting membranes. Researchers have developed various innovative designs to overcome this issue, but continuous water splitting in separated tanks remains a desirable approach. This study presents a novel, continuous roll-to-roll process that enables fully decoupled hydrogen evaluation reaction (HER) and oxygen evolution reaction (OER) in two separate electrolyte tanks. The system utilizes specially designed "cable-car" electrodes (CCE) that cycle between the HER and OER tanks, resulting in continuous hydrogen production with a purity of over 99.9% and Coulombic efficiency of 98% for prolonged periods. This membrane-free water splitting system offers promising prospects for scaled-up industrial-scale green hydrogen production, as it reduces the cost and complexity of the system, and allows for the use of renewable energy sources to power the electrolysis process, thus reducing the carbon footprint of hydrogen production.

Ultrafast heating to boost the electrocatalytic activity of iridium towards oxygen evolution reaction.

Efficient electrocatalysts are in great demand for renewable energy storage systems. Herein, we propose an ultrafast heating strategy to fabricate an efficient Ir/CP-UH catalyst for the oxygen evolution reaction (OER). Experimental results demonstrated that the ultrasmall Ir nanoparticles (≈1-3 nm) and clusters (<1 nm) were highly dispersed on the carbon paper support after a short thermal shock (∼5 s). The catalyst showed a low overpotential of 260 mV at 10 mA cm-2 and remarkable mass activity of about 13.8 times higher than that of the current state-of-the-art commercial Ir/C catalyst. This ultrafast heating strategy can also be applied to other catalyst systems for OER and other electrochemical reactions.

Mechanochemical Synthesis of Pt/Nb2CTx MXene Composites for Enhanced Electrocatalytic Hydrogen Evolution.

Production of hydrogen from water splitting has been considered as a promising solution for energy conversion and storage. Since a noble metal-based structure is still the most satisfactory but scarce kind of catalyst, it is significant to allow for practical application of such catalysts by engineering the heterogeneous structure and developing green and facile synthetic strategies. Herein, we report a mechanochemical ball milling synthesis of platinum nanoclusters immobilized on a 2D transition metal carbide MXene (Nb2CTx) as an enhanced catalyst for hydrogen evolution. After annealing at 600 °C, ultrafine Pt3Nb nanoclusters are formed on the Pt/Nb2CTx catalyst. As prepared, the Pt/Nb2CTx-600 catalyst demonstrates superior electrochemical HER activity and stability with an ultralow overpotential of 5 mV and 46 mV to achieve 10 mA cm-2 and 100 mA cm-2, respectively, in comparison with other Nb2CTx-based catalysts and commercial Pt/C catalysts. Moreover, the remarkable durability is also confirmed by accelerated durability tests (ADTs) and long-term chronoamperometry (CA) tests. The excellent HER performance was attributed to high Pt dispersion and more active site exposure by the mechanochemical process and thermal treatment. Such results suggest that the mechanochemical strategy provides a novel approach for rational design and cost-effective production of electrocatalysts, also providing other potential applications in a wide range of areas.

Continuous Roll-to-Roll Production of Carbon Nanoparticles from Candle Soot.

Carbon nanoparticles (CNPs) have been considered as essential components for various applications including sensors, quantum dots, electrocatalysts, energy storages, lubrication, and functional coatings. Uniform and functional CNP materials can be obtained from candle soot. However, the production of CNPs from candle soot is not a continuous process, limiting the practical production and applications of such materials. Here, a rotating-deposition and separation system for high-efficiency production of low-cost and high-quality CNPs from candle soot is presented. The characteristic of CNPs can be controlled by adjusting the system parameters. Moreover, obtained CNPs can act as photothermal superhydrophobic anti-icing coatings on various substrates. With a sliding angle of less than 3°, water drops can keep rolling off without further nucleation of ice. The reported preparing method is suitable for large-scale applications and various kinds of surfaces and shows great potentials in the growing demands of anti-icing.

Ice as Solid Electrolyte To Conduct Various Kinds of Ions.

Water, considered as a universal solvent to dissolve salts, has been extensively studied as liquid electrolyte in electrochemical devices. The water/ice phase transition at around 0 °C presents a common phenomenon in nature, however, the chemical and electrochemical behaviors of ice have rarely been studied. Herein, we discovered that the ice phase provides efficient ionic transport channels and therefore can be applied as generalized solid-state ionic conductor. Solid state ionic conducting ices (ICIs) of Li+ , Na+ , Mg2+ , Al3+ , K+ , Mn2+ , Fe2+ , Co2+ , Ni2+ , Cu2+ , and Zn2+ , frozen from corresponding sulphate solutions, exhibit ionic conductivities ranging from ≈10-7  S cm-1 (Zn2+ ) to ≈10-3  S cm-1 (Li+ ) at temperatures spanning from -20 °C to -5 °C. The discovery of ICIs opens new insight to design and fabrication of solid-state electrolytes that are simple, inexpensive, and versatile.