Zwitterion Interlocked Diarylethene Molecules Order, Unconnected Diarylethene Molecules DisorderWi, Youngjae; Kang, Dong‐Gue; Ko, Hyeyoon; Oh, Mintaek; Jang, Junhwa; Rim, Minwoo; Lee, Kyung Min; Godman, Nicholas P.; McConney, Michael E.; Jeong, Kwang‐Un
doi: 10.1002/smll.202410466pmid: 39690865
A diarylethene‐based zwitterionic molecule (DZM) is newly synthesized for the development of smart films exhibiting reversible color change and switchable ionic conductivity in response to external light stimuli. This dual molecular building block is constructed through zwitterionic interlocking and strong phase separation between the dendron‐shaped aliphatic tails and the diarylethene head. Uniaxial shear coating and molecular self‐assembly result in anisotropically oriented nanostructures, which are further solidified through photopolymerization. In the absence of zwitterionic interlocking, DZM fails to form ordered structures and remains disordered. The anisotropically oriented nanostructures of DZM exhibit polarization‐dependent photochromic properties despite the inherent low anisotropy of a single diarylethene chromophore. Structural analysis reveals that the zwitterion‐interlocked molecular building block self‐assemble into nanocolumns that align uniaxially during the shear coating process. Alternating ultraviolet and visible light reversibly switches the ionic conductivity of the DZM thin film and a change in color is observed due to the photoisomerization of the diarylethene chromophore. Utilizing the polarization‐dependent photochromic properties, light‐sensitive smart thin films are demonstrated with potential applications in anti‐counterfeiting labels and sensors.
Organic Molecular Amino Acids Additives Containing Amide Groups for Uniform Zinc Deposition in Aqueous Zinc Ion BatteriesNiu, Bo; Zhu, Chen; Yuan, Haiyang; Xu, Wence; Liang, Yanqin; Li, Zhaoyang; Jiang, Hui; Cui, Zhenduo; Gao, Zhonghui; Zhu, Shengli
doi: 10.1002/smll.202409556pmid: 39924861
Aqueous Zn‐metal batteries have been considered as a potentially sustainable energy storage device. They often suffer from poor reversibility and cyclability due to metallic Zn dendrites and parasitic reactions. However, the previous perspectives and mechanisms, coupled with their intricate functional groups for dendrite growth, H2 evolution, and Zn metal corrosion, render the selection criteria of electrolyte additives inherently ambiguous. Herein, it takes amino acids as an example and detailed explored the impact of three typical groups ─NH2, ─COOH, and ─CO─NH2. It is identified that the primary determinant of amide groups can be used as active sites to refine the Zn2+ ion solvation structure and promote Zn deposition. At the Zn metal‐electrolyte interface, the chemisorption of amide onto the surface of the Zn anode inhibits hydrogen evolution and facilitates planar deposition of Zn. As a result, the Zn||Zn cell with optimal amino acids with amide group shows remarkable cycling durability under a current density of 10 mA cm−2. When combined with the NH4V4O10 cathode, the assembled coin cell retains ≈60% of its capacity after 500 cycles. This amino acids molecule additive, emphasize the role of amide group in fine‐tuning Zn2+ solvation structures and Zn/electrolyte interface electrochemical properties.
Engineering of Covalently Bonded Electrode/Electrolyte for Inorganic‐Based Solid‐State Lithium BatteriesWang, Linlin; Xie, Zhuohao; Wu, Xianzhi; Xiao, Yong; Hu, Hang; Liang, Yeru
doi: 10.1002/smll.202411658pmid: 39895242
Solid‐state electrolytes have garnered significant attention due to their inherent advantages in safety and electrochemical stability. Despite these benefits, the interfacial issues between the electrode and the solid‐state electrolyte continue to hinder the widespread application of solid‐state lithium batteries. The lack of effective interfacial contact, particularly in inorganic solid electrolytes (ISEs), remains a critical barrier to achieving optimal battery performance. This study proposes a strategy to address this challenge by constructing a covalent electrode/ISE interface. Strengthening the interactions between the cathode and ISE reduces interfacial resistance and enhances electrochemical stability, leading to significant improvements in battery performance. The resulting solid‐state lithium battery, featuring a stable covalent coupling at the electrode/ISE interface, demonstrates outstanding cycling stability, retaining 85% of its initial capacity after 700 cycles at 1 C. This work not only provides new insights into overcoming interfacial resistance in ISEs but also offers a promising approach for the development of high‐performance solid‐state lithium batteries.
Molecular Imprinting Strategy Enables Circularly Polarized Luminescence Enhancement of Recyclable Chiral Polymer FilmsWang, Nianwei; Hong, Ran; Zhang, Gong; Pan, Menghan; Bao, Yinglong; Zhang, Wei
doi: 10.1002/smll.202409078pmid: 39551998
Circularly polarized luminescence (CPL) plays a crucial role in the fields of optical display and information technology. The pursuit of high dissymmetry factors (glum) and fluorescence quantum yields in CPL materials remains challenging due to inherent trade‐offs. In this work, molecular imprinting technology is employed to develop novel CPL‐active polymer films based entirely on achiral fluorene‐based polymers, achieving an enhanced glum value exceeding 4.2 × 10−2 alongside high quantum yields. These chiral molecularly imprinted polymer films (MIPF) are synthesized via a systematic three‐step process: co‐assembly with limonene and a porphyrin derivative (TBPP), interchain crosslinking, and subsequent removal of small molecules. During this process, limonene acts as the chiral inducer, while TBPP serves dual roles as both the chiral enhancer and imprinted molecule. The elimination of TBPP creates chiral sites for various fluorescent molecules, facilitating full‐color CPL emission. The chiral MIPF exhibits stable CPL performance even after multiple cycles of post‐assembly and removal. Furthermore, these films can function as interfacial microreactors, enabling in situ chemical reactions that dynamically regulate CPL signals. Additionally, chiral self‐organization within achiral azobenzene polymer films can also be achieved using MIPF, serving as intense chiral light sources.
Synergy of Pyridinic‐N and Co Single Atom Sites for Enhanced Oxygen Redox Reactions in High‐Performance Zinc‐Air BatteriesAskari, Saeed; Dwivedi, Swarit; Alivand, Masood S.; Lim, Kang Hui; Biniaz, Parisa; Zavabeti, Ali; Kawi, Sibudjing; Hill, Matthew R; Duin, Adri C.T.; Tanksale, Akshat; Majumder, Mainak; Chakraborty Banerjee, Parama
doi: 10.1002/smll.202411574pmid: 39888158
Cobalt single‐atom catalysts (SACs) have the potential to act as bi‐functional electrocatalysts for the oxygen‐redox reactions in metal‐air batteries. However, achieving both high performance and stability in these SACs has been challenging. Here, a novel and facile synthesis method is used to create cobalt‐doped‐nitrogen‐carbon structures (Co‐N‐C) containing cobalt‐SACs by carbonizing a modified ZIF‐11. HAADF‐STEM images and EXAFS spectra confirmed that the structure with the lowest cobalt concentration contains single cobalt atoms coordinated with four nitrogen atoms (Co‐N₄). Electrochemical tests showed that this electrocatalyst performed exceptionally well in both oxygen reduction reaction (ORR) (E1/2 ≈ 0.859 V) and oxygen evolution reaction (OER) (Ej = 10: 1.544 V), with excellent stability. When used as a bi‐functional electrocatalyst in the air cathode of a rechargeable zinc‐air battery (ZAB), a peak power density of 178.6.1 mW cm−2, a specific capacity of 799 mA h gZn−1 and a cycle‐life of 1580 is achieved. Density functional theory (DFT) calculations revealed that the concentration and the position of the pyridinic nitrogen with Co play a critical role in determining the overpotential of this electrocatalyst for oxygen‐redox reactions. The unprecedented performance of this electrocatalyst can bring paradigm changes in the practical realization and application of metal‐air batteries.
Sacrificial Layer for Sintering Enhancements of Ceramic, Semiconductor, and Metal Films: A Universal StrategyChen, Xiangyu; Zhu, Jianqin; Tao, Zhi; Qiu, Lu
doi: 10.1002/smll.202412574pmid: 39801184
The manufacturing of thin films through selective laser sintering of micro/nanoparticles is an emerging technology that has been developing rapidly over the last two decades owing to its digitization, efficiency, and good adaptability to various materials. However, high‐quality laser sintering of different materials remains a challenge: ceramic particles are difficult to be sintered due to low absorbance; metallic particles are prone to oxidation; semiconductor particles are difficult to process for performance enhancement due to high stress. In this work, a new approach is proposed that employs an additional Indium Tin Oxide (ITO) sacrificial layer to assist laser sintering of different functional materials, which detaches after sintering without contaminating the target material. As a laser absorber, the ITO layer can raise the sintering temperature up to 2950 K, resulting in well coarsening of ceramic grains. As an oxygen barrier, the ITO layer maintains the oxidation level of the metal die below 25%. As a temperature homogenizer, the ITO layer delays the cracking and improves the performance of the semiconductor material, which in turn increases its Seebeck factor to 1.4‐fold. Therefore, the ITO sacrificial layer is a material‐friendly, purity‐neutral laser sintering strategy, which supports laser sintering of multi‐materials and high‐performance thin‐film devices.
MOF Nanosheet Enable Accelerated Redox Kinetics and Ultralow Overpotential for Light‐Assisted Li‐CO2 BatteryLin, Xiaojing; Wu, Ziyuan; Xu, Cong; Ran, Yangyang; Zhang, Jindan; Deng, Weihua; Xiang, Shengchang; Cheng, Zhibin; Zhang, Zhangjing
doi: 10.1002/smll.202411559pmid: 39887644
Lithium‐carbon dioxide (Li‐CO₂) batteries have attracted much attention due to their high energy density, low cost, and carbon sequestration. However, the sluggish conversion kinetics between CO₂ and the discharge product lithium carbonate (Li₂CO₃) have hindered their practical applications. Herein, a flower‐like photosensitive metal–organic framework (FJU‐115‐NS) has been employed as a cathodic electrocatalyst for Li‐CO₂ batteries. The FJU‐115‐NS with well‐ordered micropores and abundant exposed catalytic sites can effectively facilitate lithium ion transport and catalyze the Li₂CO₃ formation/decomposition, leading to improved battery performance. At a current density of 200 mA g⁻¹, the FJU‐115‐NS battery exhibits a substantial discharge capacity of 31579.34 mA h g⁻¹, a low overpotential of 1.31 V, and stable operation over 3200 h. Importantly, under light irradiation, the charging voltage significantly dropped from 4.45 V (without light) to 3.43 V at a high current density of 2 A g⁻¹. Additionally, the cell demonstrated an exceptionally low overpotential of just 0.45 V at a current density of 200 mA g⁻¹, highlighting its enhanced efficiency under light‐assisted conditions. This work provides valuable guidance for developing light‐assisted MOF catalysts to upgrade the longevity and energy efficiency of Li‐CO₂ batteries.