Xianli Huang

Li–CO ₂ batteries are promising due to their high theoretical energy density and CO ₂ utilization, but practical applications are limited by sluggish Li ⁺ transport, severe polarization, and unstable liquid electrolytes. Herein, we develop a novel composite solid electrolyte (CSE) by integrating polar‐segment engineering with metal–organic framework (MOF) modification. The oxygen‐containing groups of poly(allyl acetoacetate) (PAAA) provide abundant coordination sites for rapid Li ⁺ transport, while amino‐functionalized UiO‐66‐NH ₂ immobilizes TFSI ⁻ anions and promotes lithium‐salt dissociation. Density functional theory (DFT) calculations and molecular dynamics (MD) simulations reveal strengthened Li ⁺ coordination, weakened Li ⁺ –TFSI ⁻ association, and more continuous Li ⁺ diffusion pathways. Benefiting from the optimized ion‐conduction network and improved Li/electrolyte interface, the CSE exhibits a high ionic conductivity (6.64 × 10 ⁻⁴ S cm ⁻¹ at 30 °C), an enhanced Li ⁺ transference number (0.46), and oxidative stability up to 4.96 V vs. Li ⁺ /Li. Consequently, the assembled solid‐state Li–CO ₂ battery delivers a high discharge capacity of 28908 mAh g ⁻¹ at 200 mA g ⁻¹ and exceptional cycling stability over 3600 h. Separately, the PAU‐based Li–air battery under ambient‐air conditions exhibits stable cycling for 500 h. This work provides an effective strategy for interfacial and ion‐transport engineering toward high‐performance solid‐state Li–CO ₂ batteries.

The proliferation of lithium dendrites has long posed a formidable hurdle in the widespread adoption of lithium metal batteries, thereby necessitating the urgent resolution of how to effectively mitigate their growth as the paramount challenge in the realm of energy storage. Herein, we have crafted a novel sandwich‐structured current collector comprising an ethylene‐vinyl acetate polymer (EVA)/Cu₂O/Cu configuration, where the EVA thin film acts as a protective barrier, passivating the lithium metal anode, while the Cu₂O layer fosters lithiophilic sites conducive to uniform lithium nucleation. Our experiments reveal that the EVA thin film adeptly prevents direct contact and subsequent reactions between the lithium metal and the electrolyte, enhancing the ion mobility of Li+ ions, ultimately leading to a even distribution of lithium deposition. In a Li−Cu half‐cell, the incorporation of the EVA film increases the nucleation potentials but dramatically reduces polarization potentials after 50 cycles of charge‐discharge processes. Remarkably, the Li−Cu half‐cells equipped with EVA‐coated current collectors exhibit lower electrochemical resistances, translating into significantly extended cycle lives. This work indicates the sandwich architecture (thin film/lithium metal/lithiophilic compounds) is a promising contender for achieving long‐lasting, stable lithium anodes.

Composite copper foil is considered to be the future-proof anode current collector solution for lithium-ion batteries (LIBs) with high energy density, for its light weight and low cost. Polypropylene (PP) film is widely used as the support layer of composite copper foil current collectors (CCs) due to its excellent mechanical properties and chemical stability. However, the interface adhesion between the PP layer and the copper layer is weak, due to the significant difference in surface energy. In this study, we prepared a hydrophilic PP film by air plasma treatment. After magnetron sputtering and electroplating, the composite copper foil (PP@Cu-1) with strong adhesion was then successfully prepared. In the T-peel test, for PP@Cu-1, the pull required to separate PP from the copper layer is approximately 7 times that of PP@Cu-0. The PP@Cu-1 composite copper foil exhibits excellent electrochemical properties when applied to LIBs. As an anode CC material, it could be a favorable competitor to conventional commercial Bare Cu and holds broad prospects for application in high-energy-density LIBs.

Fe-N_x-C-based single-atom (SA-Fe-N-C) catalysts have shown favorable oxygen reduction reaction (ORR) activity. However, their application in proton exchange membrane fuel cells is hindered by reduced performance owing to the thick catalyst layer, restricting mass transfer and the O₂ supply. Metal-organic frameworks (MOFs) are a promising class of crystal materials, but their narrow pores exacerbate the sluggish mass-transport properties within the catalyst layer. This study developed an approach for constructing an open-pore structure in MOFs via chelation-assisted selective etching, resulting in atomically dispersed Fe atoms anchored on an N, S co-doped carbon framework. The open-pore structure reduces oxygen transport resistance in the membrane electrode assembly (MEA) with unprecedented ORR activity and stability, as evidenced by finite element simulations. In an acidic electrolyte, the OP-Fe-NC catalyst shows a half-wave potential of 0.89 V vs RHE, surpassing Pt/C by 20 mV, and a current density of 29 mA cm^-2 at 0.9 V_iR-free in the MEA. This study provides an effective structural strategy for fabricating electrocatalysts with high mass efficiency and atomic precision for energy storage and conversion devices.

Lithium metal anodes possess ultrahigh theoretical specific capacity for next-generation lithium metal batteries, but the infinite volume expansion and the growth of lithium dendrites remain a huge obstacle to their commercialization. Therefore, here, we construct a CuO-loaded 3D polyethersulfone (PES) nanofiber frame onto a lithiophilic Cu₂O/Cu substrate to promote the lithium storage performance of the composite anode, and the 3D frame can effectively alleviate the volume expansion of lithium (Li) metal anodes. Meanwhile, lithium reacts with CuO in the composite nanofiber and Cu₂O of the substrate to generate Li₂O, which can strengthen the solid electrolyte interface (SEI) layer and achieve the uniform deposition of lithium. In addition, the combination of the heat treatment method and electrospinning technology solves the problem of poor adhesion between the fiber film and the substrate. As a result, the PES/CuO-Cu₂O (PCC) composite current collector still maintains a smooth and flat lithium-depositing layer at 5 mA cm^-2. The PCC-assembled Li||Cu half-cell can operate stably for 320 cycles at 0.5 mA cm^-2, which is about 4 times that of bare Cu. Furthermore, symmetrical batteries with PCC@Li can maintain excellent cycle stability for 1770 h. Accordingly, this work provides a low-cost and highly effective strategy for stabilizing the lithium metal anode.

Traditional polyolefin separators cannot guarantee safety for lithium‐ion batteries at high temperature due to their low melting point, especially for high power discharge. Therefore, it is imperative to develop separators with excellent thermal stability. In this paper, we have prepared TiO₂ modified PVDF composite separators by electrospinning. When compared with commercial PE separators, this kind of composite separators show superior thermal stability at 160°C. In addition, it is found that the 0.5‐TiO₂@PVDF separator exhibits excellent flame retardant and optimal tension strength. Meanwhile, the 0.5‐TiO₂@PVDF separator exhibits ideal liquid electrolyte storage capacity, which improves the ionic conductivity (0.68 mS cm⁻¹). As a result, the LiCoO₂||Li cells with 0.5‐TiO₂@PVDF separator have high discharge capacity retention rate at a current density of 1 C (300 cycles) and excellent rate performance (1.75 mAh at 5 C). In short, nano‐TiO₂ modified PVDF separator has a great application prospect in high‐performance and high‐safety lithium‐ion batteries.