• Energy Research

AbstractAluminum–metal batteries show great potential as next‐generation energy storage due to their abundant resources and intrinsic safety. However, the crucial limitations of metallic Al anodes, such as dendrite and corrosion problems in conventional aluminum–metal batteries, remain challenging and elusive. Here, we report a novel electrodeposition strategy to prepare an optimized 3D Al anode on carbon cloth with an uniform deposition morphology, low local current density, and mitigatory volume change. The symmetrical cells with the 3D Al anode show superior stable cycling (>450 h) and low‐voltage hysteresis (~170 mV) at 0.5 mA cm−2. High reversibility (~99.7%) is achieved for the Al plating/stripping. The graphite | | Al‐4/CC full batteries show a long lifespan of 800 cycles with 54 mAh g−1 capacity at a high current density of 1000 mA g−1, benefiting from the high capacitive‐controlled distribution. This study proposes a novel strategy to design 3D Al anodes for metallic‐Al‐based batteries by eliminating the problems of planar Al anodes and realizing the potential applications of aluminum–graphite batteries.

Abstract To provide and improve national energy security and low-carbon green energy economy, as a government-supported research institute related to developing new and renewable energy technologies, including energy efficiency, Korea Institute of Energy Research (KIER) needs to establish a long-term strategic energy technology roadmap (ETRM) in the hydrogen economy sector for sustainable economic development. In this paper, we establish a strategic ETRM for hydrogen energy technologies in the hydrogen economy considering five criteria: economic impact (EI), commercial potential (CP), inner capacity (IC), technical spin-off (TS), and development cost (DC). As an extended research, we apply the integrated two-stage multi-criteria decision-making approach, including the hybrid fuzzy analytic hierarchy process (AHP) and data envelopment analysis (DEA) model, to assess the relative efficiency of hydrogen energy technologies in order to scientifically implement the hydrogen economy. Fuzzy AHP reflects the vagueness of human thought with interval values, and allocates the relative importance and weights of four criteria: EI, CP, IC, and TS. The DEA approach measures the relative efficiency of hydrogen energy technologies for the hydrogen economy with a ratio of outputs over inputs. The result of measuring the relative efficiency of hydrogen energy technologies focuses on 4 hydrogen technologies out of 13 hydrogen energy technologies. KIER has to focus on developing 4 strategic hydrogen energy technologies from economic view point in the first phase with limited resources. In addition, if energy policy makers consider as some candidates for strategic hydrogen technologies of the other 9 hydrogen energy technology, the performance and productivity of 9 hydrogen energy technologies should be increased and the input values of them have to be decreased. With a scientific decision-making approach, we can assess the relative efficiency of hydrogen energy technologies efficiently and allocate limited research and development (R&D) resources effectively for well-focused R&D.

Aluminum-ion batteries (AIBs) are gaining attention for large-scale energy storage due to their low cost and high theoretical capacity. However, the existing cathode materials frequently encounter rapid capacity degradation and sluggish reaction kinetics due to the strong interaction with high-charge Al3+, which limits the utilization of AIBs. Here, the Se-doping strategy is proposed to facilitate the active participation of anions in charge compensation and enhance the anionic redox process of amorphous anion-rich TiS4. A refined amount of Se doping effectively improves reaction kinetics for Al-storage and stabilizes the structure of the material, preventing polysulfide dissolution under high dealumination states. As a result, amorphous TiS3.5Se0.5 delivers unprecedented Al3+ storage performance, with a stable capacity of 210mAhg−1 at 500 mA g−1 over 400 cycles. Through detailed characterization, we reveal that a-TiS3.5Se0.5 undergoes reversible Al3+ insertion, accompanied by anionic redox processes involving S22- and Sen- species, which lays the foundation for further development of anionic-redox-based cathodes for high-performance AIBs.

A consumption-free electrochemical desalination method is demonstrated to work based on a light-driven photocathode with a Pt/CdS/CZTS/Mo architecture.

It is challenging to develop highly efficient and stable multifunctional electrocatalysts for improving the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER), and the oxygen reduction reaction (ORR) for sustainable energy conversion and storage systems such as water-alkali electrolyzers (WAEs) and hybrid sodium-air batteries (HSABs). In this work, sub-nm Pt nanoclusters (NCs) on defective NiFe layered double hydroxide nanosheets (NixFe LDHs) are synthesized by a facile electrodeposition method. Due to the synergistic effect between Pt NCs and abundant atomic M(II) defects, along with hierarchical porous nanostructures, the Pt/NixFe LDHs catalysts exhibit superior trifunctional electrocatalytic activity and durability toward the HER/OER/ORR. A WAE fabricated with Pt/NixFe LDHs electrodes needs 1.47 V to reach a current density of 10 mA cm-2, much lower than that of the mixed 20% Pt/C and 20% Ir/C catalysts. An HSAB assembled by Pt/NixFe LDHs as a binder-free air cathode displays a high open-circuit voltage, a narrow overpotential gap, and remarkable rechargeability. This work provides a feasible strategy for constructing freestanding efficient trifunctional electrocatalysts for sustainable energy conversion and storage systems.

Abstract One-step assembled CdSe/CdS (core/shell) quantum dots (QDs) were deposited onto ZnO nanowires (NWs) and characterized for their structure, morphology and optical analyses. As deposited ZnO NWs array were wurtzite in structure. During a single hydrothermal cycle a layer of ∼4 nm CdSe/CdS QDs was formed onto ZnO NWs and overgrowth evidenced with an additional 2–5 layers due to which, (a) absorbance density, and (b) Raman Shift of 1LO mode (from 286 cm −1 to 296 cm −1 ) increased and (c) the photoluminescence intensity of the near band-edge emission peak at ∼379 nm decreased. Due to more accumulation of CdSe/CdS, photoelectrochemical cells of ZnO-based photoelectrodes designed for 1–4 cycles of CdSe/CdS onto indium-tin-oxide substrate demonstrated increasing power conversion efficiency trend from 0.18% to 1.29% whereas, for 5th cycle power conversion efficiency, due to an increased series resistance, decreased to 1.12% on account of an accumulation of several QDs.

La conversion catalytique des polysulfures apparaît comme une approche prometteuse pour améliorer la cinétique et atténuer le transfert des polysulfures dans les batteries lithium-soufre (Li–S), en particulier dans des conditions de charge élevée en soufre et d'électrolyte pauvre. Nous présentons ici une architecture de séparateur qui incorpore des sites de liaison à deux bornes (DTB) dans un cadre de carbone dopé à l'azote, composé de grappes polaires Co0.85Se et Co (Co/Co0.85Se @NC), pour améliorer la durabilité des batteries Li-S. Les amas uniformément dispersés de Co0.85Se et Co polaires offrent des sites actifs abondants pour les polysulfures de lithium (LiPS), permettant une conversion LiPS efficace tout en servant d'ancres grâce à une combinaison d'interactions chimiques. Les calculs de la théorie fonctionnelle de la densité, ainsi que les caractérisations Raman et de diffraction des rayons X in situ, révèlent que l'effet DTB renforce l'énergie de liaison aux polysulfures et abaisse les barrières énergétiques des réactions d'oxydo-réduction des polysulfures. Les batteries Li–S utilisant le séparateur modifié Co/Co0,85Se @ NC présentent une stabilité de cycle exceptionnelle (0,042 % par cycle sur 1000 cycles à 2 °C) et une capacité de débit (849 mAh g–1 à 3 °C), ainsi qu'une capacité surfacique impressionnante de 10,0 mAh cm–2, même dans des conditions difficiles avec une charge élevée en soufre (10,7 mg cm–2) et des environnements d'électrolyte maigre (5,8 μL mg–1). La stratégie du site DTB offre des informations précieuses sur le développement de batteries Li–S haute performance. La conversión catalítica de polisulfuros surge como un enfoque prometedor para mejorar la cinética y mitigar el transporte de polisulfuros en baterías de litio-azufre (Li–S), especialmente en condiciones de alta carga de azufre y electrolito pobre. En este documento, presentamos una arquitectura de separador que incorpora sitios de unión de doble terminal (DTB) dentro de un marco de carbono dopado con nitrógeno, que consiste en grupos polares de Co0.85Se y Co (Co/Co0.85Se @NC), para mejorar la durabilidad de las baterías de Li-S. Los grupos uniformemente dispersos de Co0.85Se y Co polares ofrecen abundantes sitios activos para los polisulfuros de litio (LiPS), lo que permite una conversión eficiente de LiPS a la vez que sirven como anclajes a través de una combinación de interacciones químicas. Los cálculos de la teoría funcional de la densidad, junto con las caracterizaciones in situ de Raman y difracción de rayos X, revelan que el efecto DTB fortalece la energía de unión a los polisulfuros y reduce las barreras energéticas de las reacciones redox de polisulfuro. Las baterías de Li–S que utilizan el separador modificado con Co/Co0.85Se @ NC demuestran una estabilidad cíclica excepcional (0.042% por ciclo durante 1000 ciclos a 2 C) y una capacidad de velocidad (849 mAh g–1 a 3 C), además de ofrecer una impresionante capacidad de área de 10.0 mAh cm–2 incluso en condiciones difíciles con una alta carga de azufre (10.7 mg cm–2) y entornos de electrolitos pobres (5.8 μL mg–1). La estrategia del sitio de DTB ofrece información valiosa sobre el desarrollo de baterías Li–S de alto rendimiento. Catalytic conversion of polysulfides emerges as a promising approach to improve the kinetics and mitigate polysulfide shuttling in lithium–sulfur (Li–S) batteries, especially under conditions of high sulfur loading and lean electrolyte. Herein, we present a separator architecture that incorporates double-terminal binding (DTB) sites within a nitrogen-doped carbon framework, consisting of polar Co0.85Se and Co clusters (Co/Co0.85Se@NC), to enhance the durability of Li–S batteries. The uniformly dispersed clusters of polar Co0.85Se and Co offer abundant active sites for lithium polysulfides (LiPSs), enabling efficient LiPS conversion while also serving as anchors through a combination of chemical interactions. Density functional theory calculations, along with in situ Raman and X-ray diffraction characterizations, reveal that the DTB effect strengthens the binding energy to polysulfides and lowers the energy barriers of polysulfide redox reactions. Li–S batteries utilizing the Co/Co0.85Se@NC-modified separator demonstrate exceptional cycling stability (0.042% per cycle over 1000 cycles at 2 C) and rate capability (849 mAh g–1 at 3 C), as well as deliver an impressive areal capacity of 10.0 mAh cm–2 even in challenging conditions with a high sulfur loading (10.7 mg cm–2) and lean electrolyte environments (5.8 μL mg–1). The DTB site strategy offers valuable insights into the development of high-performance Li–S batteries. يظهر التحويل الحفاز لعديد الكبريتيد كنهج واعد لتحسين الحركية وتخفيف انتقال عديد الكبريتيد في بطاريات الليثيوم والكبريت (Li - S)، خاصة في ظل ظروف التحميل العالي للكبريت والإلكتروليت الضعيف. هنا، نقدم بنية فاصل تتضمن مواقع ربط مزدوجة الطرف (DTB) ضمن إطار كربوني مخدر بالنيتروجين، يتكون من مجموعات Co0.85Se و Co القطبية (Co/Co0.85Se@NC)، لتعزيز متانة بطاريات Li - S. توفر المجموعات المنتشرة بشكل موحد من Co0.85Se القطبي و Co مواقع نشطة وفيرة لبولي كبريتيد الليثيوم (LiPSs)، مما يتيح تحويل LiPS بكفاءة مع العمل أيضًا كمثبتات من خلال مزيج من التفاعلات الكيميائية. تكشف حسابات نظرية الكثافة الوظيفية، جنبًا إلى جنب مع خصائص رامان في الموقع وخصائص حيود الأشعة السينية، أن تأثير DTB يقوي طاقة الارتباط بالعديد من الكبريتيدات ويقلل من حواجز الطاقة لتفاعلات الأكسدة المتعددة الكبريتيدات. تُظهر بطاريات Li - S التي تستخدم فاصل Co/Co0.85Se @ NC المعدل استقرارًا استثنائيًا في الدورة (0.042 ٪ لكل دورة أكثر من 1000 دورة عند درجتين مئويتين) وقدرة على المعدل (849 مللي أمبير في الساعة ز-1 عند 3 درجات مئوية)، بالإضافة إلى توفير قدرة مساحية مثيرة للإعجاب تبلغ 10.0 مللي أمبير في الساعة سم-2 حتى في الظروف الصعبة ذات التحميل العالي للكبريت (10.7 مجم سم-2) وبيئات الإلكتروليت الخالية من الدهون (5.8 ميكرولتر مجم-1). تقدم استراتيجية موقع DTB رؤى قيمة حول تطوير بطاريات Li - S عالية الأداء.

AbstractSimultaneously enhancing the reaction kinetics, mass transport, and gas release during alkaline hydrogen evolution reaction (HER) is critical to minimizing the reaction polarization resistance, but remains a big challenge. Through rational design of a hierarchical multiheterogeneous three‐dimensionally (3D) ordered macroporous Mo2C‐embedded nitrogen‐doped carbon with ultrafine Ru nanoclusters anchored on its surface (OMS Mo2C/NC‐Ru), we realize both electronic and morphologic engineering of the catalyst to maximize the electrocatalysis performance. The formed Ru‐NC heterostructure shows regulative electronic states and optimized adsorption energy with the intermediate H*, and the Mo2C‐NC heterostructure accelerates the Volmer reaction due to the strong water dissociation ability as confirmed by theoretical calculations. Consequently, superior HER activity in alkaline solution with an extremely low overpotential of 15.5 mV at 10 mA cm−2 with the mass activity more than 17 times higher than that of the benchmark Pt/C, an ultrasmall Tafel slope of 22.7 mV dec−1, and excellent electrocatalytic durability were achieved, attributing to the enhanced mass transport and favorable gas release process endowed from the unique OMS Mo2C/NC‐Ru structure. By oxidizing OMS Mo2C/NC‐Ru into OMS MoO3‐RuO2 catalyst, it can also be applied as efficient oxygen evolution electrocatalyst, enabling the construction of a quasi‐symmetric electrolyzer for overall water splitting. Such a device's performance surpassed the state‐of‐the‐art Pt/C || RuO2 electrolyzer. This study provides instructive guidance for designing 3D‐ordered macroporous multicomponent catalysts for efficient catalytic applications.