Energy & Environmental Science最新文献

Alloying platinum with early or late transition metals enhances its intrinsic activity toward the oxygen reduction reaction for proton exchange membrane fuel cells (PEMFCs), according to strain and ligand effects. However, these alloying effects disappear following the dissolution of non-noble metal component(s) during operation, leading to PEMFC performance degradation. In this study, we investigate PtNi nanoalloys across critical stages of their development (viz. as-synthesized, post-electrochemical activation, after membrane electrode assembly fabrication, and following accelerated stress testing) using a comprehensive set of ex situ, in situ, operando, and post mortem characterization techniques, which allows assessing the contributions from alloying and structural effects. Our results reveal that local lattice distortion, rather than global strain and ligand effects, is an important factor effectively contributing to both catalytic activity and durability in PEMFC. These finding challenges conventional electrocatalyst design strategies and validates the defect-engineering strategy for advanced fuel cell applications, independently from transition metal(s) retention.

For ultrafast-response supercapacitors, it is very challenging for typical porous carbon electrodes to exhibit both high volumetric (C_v) and areal (C_a) capacitances, especially under high rates, due to inefficient pore utilization. Here, a surface tension strategy is deployed to achieve high-density carbon electrodes by eliminating hollow voids, resulting in maximum densification and enhanced ion transport. Specifically, the hollow nanofibers transform into self-compressed nanoribbons with a volume shrinkage of 96.9% and an increase in elastic modulus by six times and electronic conductivity by eleven times. As a result, the volumetric capacitance of carbon nanoribbons (142 F cm⁻³) in an aqueous electrolyte largely exceeded those of the state-of the-art active carbon (62 F cm⁻³) and graphene films (41 F cm⁻³). At an extremely high power of 5 V s⁻¹, the 200-µm-thick nanoribbon film maintained an areal capacitance of 0.68 F cm⁻². Full devices in organic electrolytes delivered volumetric energies up to 18.9 Wh L⁻¹, more than double that of commercial supercapacitors (5–8 Wh L⁻¹) and other frontier ones. Additionally, 50 F soft-pack supercapacitors are fabricated to demonstrate their versatility in practical applications.

The coordination environment of single-atom catalysts (SACs) plays a pivotal role in determining their electronic structure and catalytic performance. Conventional planar Fe–N₄ motifs, however, often bind oxygen intermediates too strongly, limiting their activity in oxygen electrocatalysis. Here, we report a symmetry-breaking strategy coupled with nanoscale surface curvature engineering to tailor the electronic and spatial configuration of isolated Fe sites anchored on a sulfur/nitrogen co-doped highly concave carbon polyhedron (Fe–N₄S₁/SNhcC). This dual-scale structural design delivers outstanding bifunctional activity for the oxygen reduction and evolution reactions (ORR/OER), achieving a high half-wave potential of 0.933 V and a small ORR/OER potential gap (ΔE) of 0.695 V. Density functional theory calculations reveal that the asymmetric Fe–N₄S₁ coordination, modulated by surface curvature, weakens *OH binding and lowers the energy barrier for ORR. Finite element simulations further show that the local electric field generated by the concave surface enhances the adsorption of O₂ and OH⁻, thereby accelerating reaction kinetics. When applied as a cathode in quasi-solid-state Zn–air batteries, Fe–N₄S₁/SNhcC demonstrates exceptional performance across a wide temperature range (−60 to 80 °C), showing a high peak power density of 229.8 mW cm⁻² and extended cycling stability of 210/120/80 h at 20/50/100 mA cm⁻², respectively. Notably, it delivers a discharge capacity of 1.56 Ah and a cycling lifespan exceeding 2000 h at −40 °C and 2 mA cm⁻². This work highlights the importance of dual-scale structural modulation in SACs and opens new avenue for rechargeable Zn–air batteries operating under extreme conditions.

Under high-voltage conditions (>4.5 V vs. Li⁺/Li), the practical application of LiCoO₂ (LCO) is severely limited by irreversible structural degradation and interfacial instability. Herein, we propose a computationally guided “occupancy-exchange” strategy that enables the in situ self-assembly of a robust Li_xMg_yBO_z (LMBO) amorphous coating on LCO via Mg–Na ion exchange. Theoretical calculations reveal the thermodynamic feasibility and interfacial driving force of this exchange, offering fundamental insights into the spontaneous formation of a stable coating. In this architecture, Na doping into the LCO lattice enhances Li⁺ de-intercalation kinetics and bulk structural stability, while the LMBO surface layer effectively mitigates interfacial degradation by stabilizing lattice oxygen, reducing electrolyte corrosion, and preventing transition-metal dissolution. This synergistic bulk-surface stabilization strategy endows the modified LCO (N-LCO@LMBO) with exceptional cycling stability and fast-charging performance at 4.6 V, achieving a discharge capacity of 171.3 mA h g⁻¹ after 500 cycles at 1C and maintaining 163.7 mA h g⁻¹ after 1000 cycles at 3C. Remarkably, this work achieves the first demonstration of an LCO-based cathode capable of enduring 5C fast-charging at 4.7 V, maintaining 82.1% capacity after 500 cycles, setting a new benchmark for higher voltage, fast-charging lithium cobalt oxide systems. Furthermore, a pouch cell assembled with N-LCO@LMBO and graphite delivers an initial capacity exceeding 400 mA h and retains 92.8% of its capacity after 500 cycles under 3C fast-charging conditions, highlighting its potential for practical applications. Building on these results, this strategy is further extended to commercial LCO, demonstrating its universality and scalability. This work opens a new avenue for the rational design of stable layered cathode materials via targeted ion-exchange mechanisms.

Ionic defect sites at planar photovoltaic interfaces often cause the degradation of perovskite solar cells (PSCs), where uncoordinated ions and the consequent unstable counterions are the intrinsic reasons behind the interfacial instability. The present work proposes and experimentally verifies that an interfacial modifier, 4,5-dicyanoimidazole (DCI), with the ability to simultaneously anchor both cationic and anionic defect sites can passivate uncoordinated ionic defect sites and synchronously immobilize the adjacent counterions. The PSCs modified with DCI exhibited effectively suppressed ion migration, inhibited phase segregation, and obvious transition from tensile stress to compressed stress in the perovskite layer, which resulted in optimized PSCs with a remarkable champion PCE of 26.10% (certified PCE of 25.53%). Meanwhile, the unencapsulated device retained over 95% of its initial efficiency after 1600 h at maximum power point tracking, along with nearly no degradation after 12 cycles of 12-h light and 12-h dark tests, and retained 98.2% of its initial PCE over 2000 h in a nitrogen atmosphere at 85 °C.

Inverted perovskite solar cells (IPSCs) are among the most promising candidates for scalable photovoltaics, yet their buried interfaces remain a critical bottleneck that limits efficiency and long-term stability. In particular, the widespread use of aluminium oxide (Al₂O₃) nanoparticles as porous insulator contacts is hampered by severe aggregation, which obstructs charge transport and undermines perovskite crystallisation. Here, we establish a molecularly guided buried-interface engineering strategy by introducing 2-aminothiazole hydrochloride (2-ATCl) to stabilise and functionalize Al₂O₃ nanoparticles. This multifunctional molecule simultaneously prevents nanoparticle aggregation, enhances the hydrophilicity of self-assembled monolayers, releases lattice strain, and chemically passivates interfacial defects. The resulting devices deliver a power conversion efficiency (PCE) of 26.63% (certified 26.42%), alongside exceptional durability, retaining 90% of the initial performance after 2000 h of storage and 80% after 1000 h of continuous operation without encapsulation. Beyond conventional single-junction cells, this strategy also boosts the performance of wide-bandgap devices and proves compatible with diverse hole-selective monolayers, demonstrating its versatility. Our results present a generalizable molecular design principle for buried interfaces, paving the way towards efficient and durable perovskite photovoltaics.

The interfacial instability of zinc metal anodes is one of the key obstacles limiting the practical commercialization of aqueous zinc-ion batteries (AZIBs). In recent years, the introduction of small organic molecule additives into electrolytes has demonstrated great potential for regulating the zinc/electrolyte interfacial behavior. However, the unique regioisomeric effects of these additives and the structure–function relationships underlying their adsorption configurations remain largely unexplored. In this work, pyridinecarboxamide molecules were selected as a model system to systematically investigate the interfacial regulation behavior of three regioisomers—picolinamide, nicotinamide, and isonicotinamide—at the zinc metal anode. Specifically, picolinamide (PA), with its amide group positioned ortho to the pyridine nitrogen, forms a stable bidentate coordination structure. This configuration facilitates Zn²⁺ desolvation at the electrode interface and induces a uniform and compact adsorption layer formation, thereby promoting uniform zinc deposition while suppressing side reactions and dendrite growth. Consequently, the PA-containing electrolyte significantly enhances the stability of zinc anodes, achieving a cycling lifespan exceeding 6000 h in Zn//Zn symmetric cells and an average coulombic efficiency of 99.87% over 6000 plating/stripping cycles in Zn//Cu half cells. This work underscores the crucial role of regioisomerism in electrolyte additive design and provides a viable molecular-level strategy for constructing stable zinc metal anodes.

Anion exchange membrane water electrolyzers (AEMWEs) promise a route to produce low-cost H₂; however, the durability of AEMs can be hindered by ionomer degradation and water feedstock impurities. Herein, we evaluated chemical and electrochemical degradation pathways of PiperION, a common anionic ionomer, under anodic and chemically oxidizing conditions in an saline electrolyte (0.5 M NaCl). Based on X-ray photoelectron spectroscopy and electrochemical mass spectrometry data, we propose two degradation pathways: radical-mediated ionomer oxidation and chemically-mediated chlorination of the polymer backbone. We assigned the formation of C–Cl covalent bonds on the PiperION backbone to free chlorine formation under anodic electrochemical conditions in the presence of Cl⁻. Ionomer oxidation characterized by formation of C–O/CO bonds and CO₂ generation was substantially suppressed by using 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), which may act as a radical scavenger. These findings provide insight into improving the resilience of anion-exchange ionomers and designing AEMWE technologies robust to variable operation expected over long-term deployment.

A comprehensive techno-economic and environmental assessment database for global ammonia supply chains was developed across 63 countries, assessing diverse production technologies (gray, blue, yellow, pink, and green) and downstream logistics by quantifying the levelized cost of ammonia (LCOA) and life cycle greenhouse gas (GHG) emission using a harmonized framework. Results show significant global cost differentials; regions abundant in low-cost energy resources exhibit substantial economic advantages despite transport expenses, and imports can outperform domestic production in resource-constrained markets. GHG performance also varies; auto-thermal reforming ammonia with carbon capture demonstrates the lowest CO₂ avoidance costs, while green ammonia shows the lowest GHG intensity. Long-distance maritime transport can erode both cost and carbon advantages, underscoring the need to optimize trade corridors and logistics choices. Furthermore, a global decarbonization option analysis quantitatively confirmed that a full transition to blue ammonia could cut 70.9% GHG emission for a 23.2% total cost increase, while a full transition to green ammonia could achieve 99.7% GHG reduction for a 46.0% cost increase. This study provides the largest harmonized global ammonia supply chain dataset to date, providing a solid foundation for future research, enabling cross-country cost/emission comparisons and supporting supply-chain/investment optimization and policy design for deploying ammonia as a global energy carrier.

Despite many efforts to increase the photovoltaic performances of wide-bandgap (WBG, with a Br content above 20%) perovskite solar cells based on bromine–iodine (Br–I) mixed-halide perovskites, understanding the crystallization kinetics of WBG perovskite films, as well as the role of Br mixing in the crystallization kinetics, is still lacking. Furthermore, an overlooked aspect is the correlation of the halide compositions, crystallization kinetics, crystallographic structure, and charge transfer dynamics. Here, we unveil that Br–I mixed-halide WBG perovskite films undergo two intrinsically different crystallization kinetic processes. One is the intermediate solvent-complex phase-assisted growth (I-rich), and the other is top-to-bottom downward growth (Br-rich). Such downward growth (including high Br concentrations) correlates with the formation of a highly vertically oriented perovskite film, which is accompanied by defect formation caused by a dissolving and recrystallization process coupled with halide homogenization. Consequently, Br-rich WBG perovskite films exhibit enhanced charge carrier transport, but are concurrently plagued by non-radiative charge recombination. Addressing this fundamental perspective is critical to precisely tailor Br-related crystallization, which significantly affects the structure and optoelectronic properties of WBG perovskite films and devices.