High-voltage n-type organic cathode materials are critical for constructing zinc-organic batteries (ZOBs) with high energy density and long cycle life. However, the intrinsically unfavorable electronic structures and relatively high LUMO energy levels of most n-type materials often lead to sluggish kinetics, high solubility, and suboptimal discharge voltages (< 0.8 V). Here, we design a small molecule, quinoxalino[2’,3’:5,6]pyrazino[2,3-f][1,10]phenanthroline (DPQP), as a ZOB cathode by introducing locally electron-deficient motifs into the conjugated backbone of aromatic compounds. The linearly fused pyrazine units extending the pyrazine–benzene framework effectively optimize the electronic structure, thereby significantly enhancing the discharge voltage. Meanwhile, the expanded π-conjugated plane suppresses dissolution and accelerates charge-transfer kinetics. Benefiting from these features, the DPQP electrode exhibits an exceptional increase in average operating voltage from 0.61 V to 1.07 V (vs. Zn²⁺/Zn) at 0.1 A·g^–1, with an overpotential of only 140 mV. Notably, no discernible voltage decay occurs as the current density increases, indicating rapid and highly reversible redox kinetics. Furthermore, the DPQP cathode delivers outstanding cycling stability, maintaining over 2000 h of continuous operation at 0.1 A·g^–1 and retaining 82.5% of its capacity after more than 10,000 cycles at 10 A·g^–1. Remarkably, the DPQP electrode also demonstrates excellent tolerance to extreme temperatures, achieving stable electrochemical performance across a wide temperature range from –20 ℃ to 60 ℃. In addition, a series of spectroscopic and microscopic characterizations confirm the highly reversible redox behavior and Zn²⁺ storage mechanism of the DPQP cathode.

Micro-sized silicon (mSi) anodes offer high capacity for next-generation lithium-ion batteries but suffer from severe volume changes, causing unstable interphases and poor cycling. Traditional electrolytes derive unstable electrolyte/electrolyte interphases, and flammable solvents pose safety risks. Here, we introduce a non-flammable molten salt electrolyte, which consists of lithium bis(fluorosulfonyl)imide, potassium bis(fluorosulfonyl)amide, and cesium bis(fluorosulfonyl)imide in a mole ratio of 0.3:0.35:0.35 (noted as Li_0.3K_0.35Cs_0.35FSA), that forms an inorganic interphase on mSi, stabilizing the electrode/electrolyte interface. Computational and experimental insights elucidate the FSA⁻ anion decomposition-derived SEI predominantly of LiF, Li₃N, Li₂O, and Li₂S, which exhibits mechanical resilience and low interfacial resistance, effectively accommodating the significant volume expansion of silicon during lithiation/delithiation. As a result, the Li‖mSi half-cell achieves 60.7% capacity retention after 100 cycles with 99.5% average Coulombic efficiency. Overall, the Li_0.3K_0.35Cs_0.35FSA electrolyte eliminates flammability concerns while enabling robust cycling performance. This work demonstrates a safe, high-energy battery system by coupling mSi anodes with stable molten salt electrolytes, addressing both interfacial instability and safety challenges in mSi-based lithium-ion batteries.

Mesoporous carbons have been widely utilized as the sulfur host for lithium-sulfur (Li-S) batteries. The ability to engineer the porosity, wall thickness, and graphitization degree of the carbon host is essential for addressing issues that hamper commercialization of Li-S batteries, such as fast capacity decay and poor high-rate performance. In this work, highly ordered, ultrathin mesoporous graphitic-carbon frameworks (MGFs) having unique cage-like mesoporosity, derived from self-assembled Fe₃O₄ nanoparticle superlattices, are demonstrated to be an excellent host for encapsulating sulfur. The resulting S@MGFs exhibit high specific capacity (1, 446 mAh·g^-1 at 0.15 C), good rate capability (430 mAh·g^-1 at 6 C), and exceptional cycling stability (~0.049% capacity decay per cycle at 1 C) when used as Li-S cathodes. The superior electrochemical performance of the S@MGFs is attributed to the many unique and advantageous structural features of MGFs. In addition to the interconnected, ultrathin graphitic-carbon framework that ensures rapid electron and lithium-ion transport, the microporous openings between adjacent mesopores efficiently suppress the diffusion of polysulfides, leading to improved capacity retention even at high current densities.