ACS Energy Letters 最新文献

This study introduces a multicomponent solvent engineering approach for constructing high-quality 2D/3D metal halide perovskite (MHP) heterostructures, addressing vertical inhomogeneity in ultrathin 2D capping layers for perovskite solar cells (PSCs). Through synergistic solvent coordination, isopropyl alcohol spatially confines 2D layer formation at the 3D perovskite surface, while dimethyl sulfoxide induces controlled 3D matrix dissolution to enable vertical phase propagation. Acetonitrile optimizes solvent penetration dynamics, achieving 2D layers with exceptional spatial homogeneity across multiple cation systems. The optimized PDAI₂-derived 2D/3D architecture demonstrates a certified power conversion efficiency (PCE) of 25.57% (champion 26.14%) with an 85.62% fill factor, attributed to enhanced interfacial charge transport at the C₆₀/perovskite junction through reduced nonradiative recombination. The spatially uniform 2D capping layer confers remarkable operational stability, retaining 92% initial PCE after 5,000 h dark aging and 90% efficiency following 1,700 h maximum power point tracking under continuous 1-sun illumination.

Two-dimensional (2D) perovskites suffer from poor charge transport due to the insulating nature of typically used organic spacers. Here, we develop a triphenylamine (TPA)-functionalized semiconducting ligand, namely, DPA-PEAI, in which the TPA moiety is tethered to the ethylammonium cation. Crystallographic analysis of n = 1 2D perovskite (DPA-PEA)₂PbI₄ reveals that the propeller-like geometry and enriched phenyl rings of the TPA tail enable the formation of multifarious π-stacking interconnections between neighboring ligands. Theoretical calculations further unveil that both the binding energy and hole transfer integral are augmented between the adjacent DPA-PEA cations, in contrast to the widely used phenylethylammonium (PEA) counterpart. This cross-electronic coupling feature allows the formation of multiple hole-transfer pathways within DPA-PEA-based 2D perovskites, enabling efficient out-of-plane charge transport, as confirmed by a set of characterizations. As a consequence, 2D/3D FAPbI₃-based PSCs employing DPA-PEAI afford a champion efficiency of 25.7%, which ranks among the best efficiencies reported for conjugative ligands.

The development of solid-state batteries (SSBs) is hindered by degradation at solid–solid interfaces due to void formation and contact loss, resulting in increased impedance. We systematically investigate the roles of real and unrecoverable interfacial contact areas at the electrode/Li₆PS₅Cl interface in driving the impedance rise. By controlling contact geometries and applied pressures, we identify their distinct contributions to the impedance and quantify their influence on the interfacial resistance and transport. Experiments reveal that interfacial resistance follows power law scaling, with exponents of −1 for recoverable contact area and −0.5 to −0.67 for pressure, respectively. Moreover, distributed contacts result in lower impedance due to smaller potential gradients and a more uniform electrical potential distribution. Simulations of the geometries with unrecoverable contact loss predict interfacial resistances in agreement with experiments. Our work highlights the influence of unrecoverable and recoverable contact losses on SSB impedance while quantifying the effectiveness of mitigation strategies.

Gel polymer electrolytes (GPEs) instead of liquid electrolytes can greatly improve the lifespan and safety of sodium metal batteries (SMBs). However, inferior interface stability against Na metal and sluggish reaction kinetics restrict their practical use. Herein, a cross-linked GPE (c-GPE) is proposed by in situ copolymerization of ethoxylated trimethylolpropane triacrylate (ETT) and trifluoroethyl methacrylate (TM) in a liquid electrolyte. The uniquely fabricated c-GPE exhibits impressive ionic conductivity, a wide electrochemical window, low flammability, and favorable Na metal compatibility. Particularly, the functional copolymer chain regulates the Na⁺ solvation structure with lower desolvation energy by a strong cation-dipole (in polymer) interaction. Consequently, full cells based on the Na₃V₂(PO₄)₃ (NVP) cathode (NVP|c-GPE|Na) display an ultralong cycle life (>3000 cycles), remarkable rate capability (up to 15C), and wide temperature adaptability. The work offers new insight into constructing a Na⁺ coordination environment, achieving more facile desolvation by the polymer chain design of the GPE used for developing advanced SMBs.