Achieving long-term operational stability alongside high power conversion efficiency remains one of the most critical challenges for organic solar cells (OSCs), as interfacial degradation under heat, humidity, and continuous illumination severely limits device lifetime. Although many studies report improved stability under individual stress conditions, few OSC studies have demonstrated extended durability across multiple stress conditions. Here, we report a bilateral bilayer interface engineering strategy centered on a novel coordination-engineered cathode stabilization material, Cu-bathocuproine (BCP), formed by coordinating Cu with conventional BCP. Introduced as an overlayer on aliphatic amine-functionalized perylene-diimide (PDINN), Cu-BCP serves as an efficient electron-extraction interlayer and a chemically stabilized buffer that suppresses detrimental interfacial reactions with the non-fullerene acceptor. Combined with a self-assembled monolayer/metal oxide anode bilayer, [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz)/MoOx, OSCs with the structure of indium tin oxide (ITO)/PDINN/Cu-BCP/PM6:L8-BO:PC71BM/2PACz/MoOx/Ag achieve a power conversion efficiency of 16.70%, surpassing the reference devices based on PDINN (14.58%) and PDINN/BCP (15.05%). Importantly, the bilateral bilayer devices exhibit substantially enhanced durability under multiple independent stress conditions, retaining 80% of their initial efficiency after 1,200 h in air storage, 1,320 h at 65 °C/65% relative humidity, and 1,008 h under continuous 1-sun illumination, corresponding to the longest T80 lifetime among PDINN-based devices. The improved stability is associated with suppressed trap-assisted recombination, reduced leakage current, and lower charge-transfer resistance. Moreover, large-area modules deliver an efficiency of 14.57% with a 54 cm2 active area, indicating an 87% cell-to-module ratio. These results demonstrate that ultrathin stabilization-layer design within bilateral bilayer interfaces is an effective route toward efficient, stable, and scalable OSCs.
Efficient thermal management remains a key challenge in lithium-ion battery systems, as temperature fluctuations can compromise performance and safety. Composite phase change materials (CPCMs) offer high latent heat and passive temperature regulation but are often hindered by leakage and flammability. In this study, a passive battery thermal management system incorporating an intrinsically flame-retardant CPCM was developed. Hydroxylated ammonium polyphosphate (HAPP) was synthesized through a cation-exchange reaction and integrated into a hexamethylene diisocyanate (HDI)-crosslinked polyethylene glycol (PEG) network, providing structural support and flame-retardant functionality. A Polyethylene glycol (PEG)/Hexamethylene diisocyanate (HDI)/HAPP/expanded graphite (EG) composite, denoted as PHHE, was prepared through chemical crosslinking. The resulting three-dimensional HAPP-PEG-HDI network effectively restricted the macroscopic leakage of PEG. PHHE exhibits an initial latent heat of 111.35 J/g and a mass retention of 99.88% after aging at 80 °C for 5 h. During battery-module testing at a discharge rate of 2 C, the PHHE-based battery module reached a maximum temperature of 52.08 °C, indicating its passive temperature-regulation capability. These results demonstrate that PHHE integrates thermal-energy storage, shape stability, flame-retardant functionality, and battery temperature regulation, providing a potential material approach for the thermal management of battery packs and related energy-storage systems.
An atomic-level understanding of anion and cation intercalation is essential for advancing alkali-metal-ion electrodes and anchoring metal polysulfides. Sodium batteries present a more sustainable alternative to lithium-based systems. Developing electrode materials that support both sodium-ion storage and sodium-polysulfide conversion, each in its