ABSTRACT The solid electrolyte interphase in lithium metal batteries determines cycling stability but often suffers from the incomplete decomposition of fluorinated components. Herein, we demonstrate that suspending LiF and Li 2 O particles in a carbonate‐based electrolyte promotes the defluorination of fluoroethylene carbonate and lithium hexafluorophosphate. These particles preferentially adsorb fluorinated electrolyte species and induce electronic polarization, thereby modulating their redox reactivity and facilitating interfacial decomposition toward LiF. The generated LiF, together with the trace dissolution and interfacial reprecipitation of suspended LiF particles, continuously enriches the electrode surface with LiF‐rich inorganic species. This process results in the formation of a bilayer interphase on both the lithium metal anode and LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode, featuring a flexible inner layer and a dense LiF‐rich outer layer. The resulting interphase suppresses lithium dendrites, mitigates parasitic reactions, and enables 2400 h of stable cycling in symmetric cells and 85.6% capacity retention after 400 cycles in full cells. By introducing suspended LiF/Li 2 O particles to regulate the interfacial decomposition of fluorinated electrolyte species, this work provides an effective electrolyte‐design strategy for constructing robust interphases in lithium metal batteries.
ABSTRACT Block copolymer electrolytes exhibit a complex interplay between self‐assembled morphology, ion transport, and mechanical properties under galvanostatic battery cycling. Here, we propose a novel operando methodology combining concurrent rheology and electrochemical measurements upon dc polarization for a lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) doped polystyrene‐ block ‐poly (ethylene oxide) diblock copolymer electrolyte. Time‐resolved measurements of the viscoelastic and electrochemical responses to the galvanostatic stimulus permit to uncover the effective response of the block copolymer electrolyte, tracking ion transport‐mechanical‐morphological properties simultaneously. Corroborated by scanning transmission electron microscopy (STEM) imaging, we observe the block copolymer transitioning from unperturbed, increasingly aligned lamellae to reorganized self‐assembled nanostructures as the applied current density approaches the limiting current and, beyond its onset, the nanomorphology evolves toward gyroid and hexagonal phases. The diffusion coefficients decrease as current density increases, which is attributed to concentration polarization phenomena. Lastly, this methodology identifies a direct coupling between interfacial electrochemical processes and mechanical properties, highlighting the intimate interplay between interfacial phenomena and rubbery plateau modulus upon current densities.
ABSTRACT Lithium‐carbon dioxide (Li–CO 2 ) batteries present a promising strategy for coupling high‐energy storage with CO 2 utilization, yet their development is impeded by sluggish kinetics and severe polarization associated with insulating discharge products. Achieving selective and reversible two‐electron conversion toward Li 2 C 2 O 4 remains a critical challenge for improving energy efficiency and cycling stability. Herein, we report electronically asymmetric dual‐atom Fe–N–Mo catalytic pairs anchored on a highly conjugated N‐doped carbon (NC) framework, forming Fe 1 ‐Mo 1 integrated catalytic pairs (Fe 1 ‐Mo 1 /ICPs) to promote a reversible two‐electron Li 2 C 2 O 4 conversion pathway. The πconjugated highly conjugated N‐doped carbon framework stabilizes atomically dispersed Fe and Mo sites while enhancing inter‐site electronic coupling. Within the proposed heteronuclear Fe–N–Mo configuration, intrinsic electronic asymmetry generates electrophilic Fe and nucleophilic Mo sites, enabling dynamic charge redistribution and complementary catalytic behavior. Such a donor‐acceptor bridge effectively regulates intermediate adsorption/desorption and suppresses competing reaction pathways, thereby favoring the selective and reversible formation of Li 2 C 2 O 4 . Operando spectroscopic analysis confirms the preferential reversible Li 2 C 2 O 4 evolution during cycle, while density functional theory calculations reveal substantially reduced energy barriers for key reaction intermediates. Benefiting from the unique electronic environment and synergistic effects of asymmetric dual‐atom sites, the FeMoCN catalyst delivers outstanding electrochemical performance.
ABSTRACT For wide‐bandgap mixed‐halide perovskites, quasi‐two‐dimensional (quasi‐2D) surface reconstruction using bulky‐cation spacers is widely employed to passivate surface defects and disrupt halide migration pathways. Nevertheless, under operational stress, conventional ammonium‐based spacers can undergo deprotonation, destabilizing the low‐dimensional surface layer and weakening its function. Herein, we report an organic‐spacer charge‐state control strategy for the surface modification of Cs 0.2 FA 0.8 PbI 1.8 Br 1.2 wide‐bandgap perovskites. This strategy involves combining octylammonium (OA) with N ‐methylsulfanilic acid (NMSA) to form NMSAO, a charge‐neutralized ammonium–sulfonate modifier state. This configuration induces an associated Ruddlesden–Popper‐like quasi‐2D phase at the perovskite surface that suppresses trap‐mediated recombination, facilitates interfacial charge extraction, and disrupts halide‐ion migration pathways. As a result, the NMSAO‐treated perovskite solar cells (PSCs) achieved a power conversion efficiency (PCE) of 19.83% and an open‐circuit voltage ( V OC ) of 1.326 V, compared with 17.30% and 1.197 V for the untreated control PSCs. Furthermore, the NMSAO‐treated PSCs retain 93.59% of their initial PCE after 500 h of continuous illumination under ISOS‐L‐1 conditions and more than 93% after 500 h of thermal aging at 85°C. This study demonstrates the effectiveness of a charge‐neutralized organic spacer for quasi‐2D surface reconstruction in wide‐bandgap mixed‐halide PSCs, improving both photovoltaic performance and operational stability.
ABSTRACT Single‐atom catalysts (SACs) have emerged as a research frontier in electrocatalysis. However, conventional SACs possess single metal active sites, which hardly break the symmetry of geometric and electronic structure of M–N 4 . To address this limitation, porous trimetallic single‐atom catalysts (TACs) is fabricated via ZIF‐8‐derived ion exchange and gas‐phase etching methods. The catalyst features Fe, Co, and Zn single atoms with a special M–N 4 configuration where the three metal atoms share one N ligand. And axial coordination structure exists between Zn and Cl atoms. It exhibits outstanding oxygen reduction activity and stability under acidic/alkaline conditions, with a half‐wave potential of 0.81 V/0.96 V and loss of 4 mV/8 mV after 30 000 cycles. Only 6.5% performance decay is observed after 2163 h of charge‐discharge cycling in zinc‐air batteries (ZABs). Physicochemical characterization and density functional theory (DFT) calculations reveal that the trimetallic configuration breaks the geometric and electronic structural symmetry, optimizing the adsorption of intermediates during the oxygen reduction reaction (ORR). Axial coordination of Cl on Zn facilitates the bridge‐type adsorption of O 2 and breaks the linear scaling relationship. This work offers a novel strategy to break the symmetry of geometric and electronic structure of SACs and regulate reaction pathways.
