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Verified CAS / Academic Author2 Decoded Studies

Prof. LI Chi

Peking University

Research Publications & English Decoded Briefs

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SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3941-2

Cation-Mediated Assembly of Aluminum Molecular Rings and Polyoxometalates: A Solution-Processable and Synergistic Dielectric Dopant

The precise and directed assembly of multicomponent aggregates remains a central challenge in materials chemistry, particularly the integration of neutral clusters. This study introduces a 'cation-mediated co-crystallization' strategy to overcome electrostatic assembly barriers between neutral aluminum molecular rings and polyoxometalates (POMs). By controllably functionalizing the rings with cationic moieties, the approach bypasses traditional 'ion-pair' limitations, enabling incorporation of diverse neutral clusters. The strategy exhibits structural extensibility, with cationic sites adjustable on ring exteriors or interiors, and potential extension to various polyanionic systems. The resulting hybrid materials demonstrate outstanding solution processability. When incorporated as dielectric dopants in a polymer matrix, they achieve a synergistic '1+1>2' effect: aluminum rings contribute high capacitance density (~11.19) and low dielectric loss (~0.03), while POMs provide high breakdown strength (~740 MV m−1). This work establishes a paradigm for directed macroscopic functional assembly via molecular-level cluster interaction 'encoding'.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4196-x

A Critical Artifact in Aqueous Zinc-Ion Batteries: Charging under Aerial Oxidation Distorts Discharged-Cathode Characterization

Aqueous zinc-ion batteries (AZIBs) are promising for safe, low-cost energy storage, but accurate cathode characterization is essential for understanding their electrochemical behavior. This study identifies a critical artifact: routine air-drying of deeply discharged cathodes triggers spontaneous aerial oxidation, which distorts post-mortem analysis. Using NH4V4O10 (NVO) as a model cathode, we show that ex situ X-ray photoelectron spectroscopy (XPS) of discharged electrodes reveals only V4+/V5+ signals, with no detectable V3+, implying a theoretical capacity of only 245.5 mAh g−1, yet experimentally measured capacity reaches ~334.5 mAh g−1 at 0.2 A g−1. This discrepancy arises because air exposure during sample preparation oxidizes the reduced vanadium states, leading to a self-charging effect that recovers ~83% of capacity. Electrochemical re-oxidation (EO-NVO) is superior to aerial oxidation (AO-NVO), producing a stable, long-range ordered bulk structure with efficient Zn2+ transport channels, whereas aerial oxidation induces only superficial changes and structural disorder. These findings resolve a key analytical inconsistency and reveal a novel capacity-contribution pathway, with direct implications for accurate material assessment and advanced battery design.