Electrospinning-assisted porous skeleton electrolytes for semi-solid Li-O2 batteries.

Solid-state lithium-oxygen batteries offer great promise in meeting the practical demand for high-energy-density and safe energy storage. We have developed fibrous gel polymer electrolytes (GPEs) using a polyacrylonitrile (PAN) matrix via electrospinning. The 3D structure of GPEs enhances electrolyte absorption, while the interconnected design promotes strong interactions between Li+ and polar groups within the PAN matrix, thereby improving ion transport efficiency. In practical tests, both lithium symmetric cells and Li-O2 batteries demonstrated the ability to operate at high current densities over long cycles.

One Stone, Three Birds: An Air and Interface Stable Argyrodite Solid Electrolyte with Multifunctional Nanoshells.

Li6 PS5 Cl (LPSC) solid electrolytes, based on Argyrodite, have shown potential for developing high energy density and safe all-solid-state lithium metal batteries. However, challenges such as interfacial reactions, uneven Li deposition, and air instability remain unresolved. To address these issues, a simple and effective approach is proposed to design and prepare a solid electrolyte with unique structural features: Li6 PS4 Cl0.75 -OF0.25 (LPSC-OF0.25 ) with protective LiF@Li2 O nanoshells and F and O-rich internal units. The LPSC-OF0.25 electrolyte exhibits high ionic conductivity and the capability of "killing three birds with one stone" by improving the moist air tolerance, as well as the interface compatibility between the anode or cathode and the solid electrolyte. The improved performance is attributed to the peculiar morphology and the self-generating and self-healing interface coupling capability. When coupled with bare LiCoO2 , the LPSC-OF0.25 electrolyte enables stable operation under high cutoff voltage (≈4.65 V vs Li/Li+ ), thick cathodes (25 mg cm-2 ), and large current density (800 cycles at 2 mA cm-2 ). This rationally designed solid electrolyte offers promising prospects for solid-state batteries with high energy and power density for future long-range electric vehicles and aircrafts.

Coal-based ultrathin N-doped carbon nanosheets synthesized by molten-salt method for high-performance lithium-ion batteries.

Coal is a typical fossil fuel and it is also a natural carbon material, therefore, converting it to functional carbon materials is an effective way to enhance the economic advantages of coal. Here, ultrathin N-doped carbon nanosheets were prepared from low-cost coal via a handy and green molten-salt method, which shown excellent performance for lithium-ion batteries (LIBs). The formation mechanism of ultrathin nanosheets was studied in detail. The eutectic molten salts possess low melting points and become a strong polar solvent at the calcined temperature, making the acidified coal miscible with them in very homogeneously state. Therefore, they can play a gigantic role inin situpore-forming during the carbonization and induce the formation of ultrathin nanosheets due to the salt ions. Simultaneously, the ultrathin N-doped carbon nanosheets with rich defects and controllable surface area was smoothly prepared without any more complex process while revealing brilliant electrochemical performance due to rich ion diffusion pathways. It delivers reversible capacity of 727.0 mAh g-1at 0.2 A g-1after 150 cycles. Thus, the molten-salt method broadens the avenue to construct porous carbon materials with tailor-made morphologies. Equally important, this approach provides a step toward the sustainable materials design and chemical science in the future.

A Flexible Ceramic/Polymer Hybrid Solid Electrolyte for Solid-State Lithium Metal Batteries.

Ceramic/polymer hybrid solid electrolytes (HSEs) have attracted worldwide attentions because they can overcome defects by combining the advantages of ceramic electrolytes (CEs) and solid polymer electrolytes (SPEs). However, the interface compatibility of CEs and SPEs in HSE limits their full function to a great extent. Herein, a flexible ceramic/polymer HSE is prepared via in situ coupling reaction. Ceramic and polymer are closely combined by strong chemical bonds, thus the problem of interface compatibility is resolved and the ions can transport rapidly by an expressway. The as-prepared membrane demonstrates an ionic conductivity of 9.83 × 10-4 S cm-1 at room temperature and a high Li+ transference numbers of 0.68. This in situ coupling reaction method provides an effective way to resolve the problem of interface compatibility.

Solar-Driven H2 O2 Generation From H2 O and O2 Using Earth-Abundant Mixed-Metal Oxide@Carbon Nitride Photocatalysts.

Light-driven generation of H2 O2 only from water and molecular oxygen could be an ideal pathway for clean production of solar fuels. In this work, a mixed metal oxide/graphitic-C3 N4 (MMO@C3 N4 ) composite was synthesized as a dual-functional photocatalyst for both water oxidation and oxygen reduction to generate H2 O2 . The MMO was derived from a NiFe-layered double hydroxide (LDH) precursor for obtaining a high dispersion of metal oxides on the surface of the C3 N4 matrix. The C3 N4 is in the graphitic phase and the main crystalline phase in MMO is cubic NiO. The XPS analyses revealed the doping of Fe(3+) in the dominant NiO phase and the existence of surface defects in the C3 N4 matrix. The formation and decomposition kinetics of H2 O2 on the MMO@C3 N4 and the control samples, including bare MMO, C3 N4 matrix, Ni- or Fe-loaded C3 N4 and a simple mixture of MMO and C3 N4 , were investigated. The MMO@C3 N4 composite produced 63 µmol L(-1) of H2 O2 in 90 min in acidic solution (pH 3) and exhibited a significantly higher rate of production for H2 O2 relative to the control samples. The positive shift of the valence band in the composite and the enhanced water oxidation catalysis by incorporating the MMO improved the light-induced hole collection relative to the bare C3 N4 and resulted in the enhanced H2 O2 formation. The positively shifted conduction band in the composite also improved the selectivity of the two-electron reduction of molecular oxygen to H2 O2 .

Enhanced Activity of Supported Ni Catalysts Promoted by Pt for Rapid Reduction of Aromatic Nitro Compounds.

To improve the activities of non-noble metal catalysts is highly desirable and valuable to the reduced use of noble metal resources. In this work, the supported nickel (Ni) and nickel-platinum (NiPt) nanocatalysts were derived from a layered double hydroxide/carbon composite precursor. The catalysts were characterized and the role of Pt was analysed using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS) mapping, and X-ray photoelectron spectroscopy (XPS) techniques. The Ni2+ was reduced to metallic Ni° via a self-reduction way utilizing the carbon as a reducing agent. The average sizes of the Ni particles in the NiPt catalysts were smaller than that in the supported Ni catalyst. The electronic structure of Ni was affected by the incorporation of Pt. The optimal NiPt catalysts exhibited remarkably improved activity toward the reduction of nitrophenol, which has an apparent rate constant (Ka) of 18.82 × 10-3 s-1, 6.2 times larger than that of Ni catalyst and also larger than most of the reported values of noble-metal and bimetallic catalysts. The enhanced activity could be ascribed to the modification to the electronic structure of Ni by Pt and the effect of exposed crystal planes.