Acta Energiae Solaris Sinica•2026•DOI: 10.19912/j.0254-0096.tynxb.202608_9705
Conventional full-bridge and half-bridge LLC converters suffer from narrow input voltage gain ranges and elevated switch voltage stress, limiting their deployment in photovoltaic, wind, and electric vehicle DC-DC interfaces where source voltage fluctuates widely. This paper proposes a wide-input series half-bridge LLC resonant converter that halves the switch voltage stress via a stacked input capacitor architecture. Two operating modes are analyzed: a high-gain (HG) mode for input voltages above a threshold Vin,th, and a low-gain (LG) mode employing frequency doubling for input voltages below Vin,th. A PSM-PWM-PFM hybrid control method enables stable mode transitions, while a PSM-PWM hybrid voltage-balancing control compensates for input capacitor voltage imbalance. A 600 W prototype operating over a 100-400 V input range validates the theoretical analysis and control feasibility. The converter maintains a narrow resonant network frequency range across the full input span, simplifying magnetic component design and preserving soft-switching characteristics. Experimental results confirm zero-voltage switching (ZVS) for primary switches, balanced input capacitor voltages, and stable mode transitions under varying load and input conditions. The proposed topology and control strategy offer a practical solution for wide-voltage DC-DC conversion in renewable energy and electric vehicle charging systems, achieving high efficiency and reduced voltage stress without the complexity of clamped or flying-capacitor three-level topologies.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4477-7
The rapid demand for high-energy-density lithium batteries necessitates advanced solid-state electrolytes (SSEs) to overcome the safety and performance limitations of conventional liquid counterparts. Macrocyclic compounds, with their well-defined cavities, programmable binding sites, and tunable self-assembly, have emerged as powerful molecular regulators for designing next-generation SSEs. This review examines recent advancements in macrocyclic compound-based SSEs by categorizing their functions into four fundamental supramolecular regulation paradigms: cation-centered regulation (e.g., crown ethers), anion-centered regulation (e.g., calixarenes and calixpyrroles), channel-dominated transport (e.g., cyclodextrins), and hybrid regulation (e.g., cucurbiturils). We elucidate how these macrocycles precisely control ion coordination, modulate migration dynamics, and reshape interfacial chemistry, leading to enhanced ionic conductivity, improved Li+ transference numbers, suppressed lithium dendrite growth, and superior interfacial stability. While each paradigm offers distinct advantages, the most promising SSEs often leverage synergistic combinations of these strategies. Finally, we highlight the remaining challenges, including synthetic complexity and multi-objective performance trade-offs, and propose future research directions for developing highly efficient and durable macrocycle-based solid-state lithium batteries.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3689-9
Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics; however, conventional thermoelectric materials face significant drawbacks, including high ionic concentrations, toxicity, and limited thermoelectric efficiency. Here, we report an ionic thermoelectric hydrogel designed through precise supramolecular chemistry, utilizing dual molecular interactions: host-guest complexation of α-cyclodextrin (α-CD) with I3− ions and hydrogen bonding between polyvinyl alcohol (PVA) polymer chains and I3−. This molecularly tailored approach markedly amplifies thermoelectric performance, achieving a high thermopower of 2.21 mV/K and a tenfold enhancement in peak power output at an exceptionally low iodine concentration (10 mmol/L I− + 2.5 mmol/L I3−). The hydrogel maintains excellent biocompatibility and mechanical robustness, suitable for direct skin contact. Demonstrated applications include flexible thermoelectric devices generating nearly 100 mV from body heat and sensor arrays capable of motion and spatial temperature sensing. These results underscore the substantial potential of supramolecularly designed ionic thermoelectric hydrogels for wearable energy harvesting, personalized healthcare monitoring, and advanced human-computer interfaces.