作者机构：
[Meng, Ruizhi; Cui, Zhexin; Yun, Di] Xi An Jiao Tong Univ, Sch Nucl Sci & Technol, Xian 710049, Peoples R China.;[Cui, Zhexin; Lozano-Perez, Sergio] Univ Oxford, Dept Mat, Parks Rd, Oxford OX1 3PH, England.;[Liu, Junkai] Xidian Univ, Sch Adv Mat & Nanotechnol, Xian 710126, Peoples R China.;[Deng, Huiqiu; Liu, Guangdong; Deng, HQ] Hunan Univ, Sch Phys & Elect, Changsha 410082, Peoples R China.;[Liu, Xiaochun; Tang, Guogao] Changsha Univ Sci & technol, Inst Met, Coll Mat Sci & Engn, Changsha 410082, Peoples R China.
通讯机构：
[Yun, D ] X;[Deng, HQ ] H;Xi An Jiao Tong Univ, Sch Nucl Sci & Technol, Xian 710049, Peoples R China.;Hunan Univ, Sch Phys & Elect, Changsha 410082, Peoples R China.
关键词：
Zirconium alloy;High-temperature oxidation;Effect of tin;Nanovoids
摘要：
The oxidation behavior of zirconium alloy in high-temperature steam plays a dominant role in the operation of nuclear reactors under accident conditions. The present work investigated the effect of Sn on the oxidation behavior of zirconium alloys in high-temperature steam at 1000 degrees C. The results of scanning electron microscopy (SEM), metallographic microscopy and synchrotron X-ray diffraction (S-XRD) analyses show that there are three layers in the oxidized sample, including prior beta-Zr, alpha-Zr(O) and ZrO2. High resolution analyses conducted in these layers by transmission electron microscopy (TEM) show that Sn atoms segregate around the oxide-metal (O-M interface and Zr-Sn intermetallic precipitates only present in the oxide film. Clear atomic arrangements of Zr5Sn3 were obtained by TEM, resulting in accurate identification of the Zr-Sn intermetallic phase. Also, TEM energy dispersive spectroscopy (EDS) maps show that Zr-Sn particles invariably accompany the segregation or precipitation of Nb. However, no clear precipitation sequence was observed, which suggests that a co-precipitation mechanism of Sn and Nb is in operation. As oxidation proceeds, nanovoids next to the Zr-Sn intermetallic particles were observed accompanied by local areas deficient in oxygen, identified as ZrO. Combining the interdiffusion trend obtained by Density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, a mechanism for the transformation from the Zr-Sn intermetallic precipitates to nanovoids was proposed. This proposed mechanism may shed new light into the role of Sn in the oxidation resistance of zirconium alloy under LOCA conditions.
摘要：
High-temperature titanium alloys' thermal stability and creep resistance are significant during service in high temperatures. This study systematically investigated the thermal stability and mechanical properties of Ti-6.5A1-2.5Sn-9Zr-0.5Mo-1Nb-1W-0.3Si- x Sc ( x , 0-0.5 wt.%) at 650 degrees C. The lamellar secondary alpha phase is refined and the formation of Sc2 O3 is increased with the increasing scandium ( Sc ) additions, which improves the strength of the alloy, while excessive Sc2 O3 becomes the crack source and deteriorates the plasticity. The oxygen content in the matrix is reduced by the interaction between Sc and oxygen, inhibiting the growth of the Ti3 Al phase and improving the thermal stability of the alloy. Meanwhile, Sc accelerates the dissolution of the residual ,B phase and precipitation of fine, diffusely distributed ellipsoidal silicides, which strongly prevents dislocation movement. The enhancement of creep resistance for the Sc -containing alloy is attributed to the refined lamellar secondary alpha phases, Sc2 O3 particles, Ti3 Al phase, and silicides, especially the precipitated silicides. Eventually, the 0.3Sc alloy shows optimal thermal stability (the plasticity loss rate 17.3%) and creep resistance (steady-state creep rate 4.4 x 10-7 s-1 ). The investigation results provide new insights into the mechanism and thermal stability improvement in high-temperature titanium alloys modified by rare earth (RE).(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
摘要：
Vanadium redox flow batteries (VRFBs) are promising energy storage systems with the potential to bridge the gap between intermittent renewable electricity generation and continuous supply of reliable electricity. The electrodes found in VRFB cells affect their energy efficiency (EE) and power density. It is important to fabricate electrodes with intriguing properties to enable VRFBs to have high performance. Herein, the abundant and cost-effective lignin is employed as the precursor to produce amorphous carbon particles after undergoing thermal decomposition treatment. The carbon particles cover the surface of carbon felt (CF). The resulting CF modified by lignin-derived carbon particles (Lignin-CF) with increased active sites and improved hydrophilicity displays superior electrochemical activity towards the VO(2)(+)/VO(2+) pair than both the pristine CF and the heated bare CF. Remarkably, the VRFB consisting of Lignin-CF which acts as the positive electrode shows high performance in terms of the average EE (83.3%) and average voltage efficiency (VE) (85.0%) over 1000 cycles (long cycling life) for more than 16days at 100mAcm(-2), and high power density of 1053.2 mW cm(-2). It is noted that the EE and VE are comparable to the highest reported value of CF modified by carbon-based materials, aside having evidently longer cycling life. This study provides a feasible strategy for fabricating an affordable electrode for high-performance VRFBs.
作者机构：
[Jiao, Zengkai; Deng, Zejun; Gang, Yuan; Zhou, Kechao; Deng, ZJ; Wei, Qiuping; Wang, Xiang; Ma, Li; Wei, QP; Li, Haichao] Cent South Univ, Sch Mat Sci & Engn, State Key Lab Powder Met, Changsha 410083, Peoples R China.;[Zhang, Long] Changsha Univ Sci & Technol, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Wang, Yijia] Cent South Univ, Adv Res Ctr, Changsha 410083, Peoples R China.
通讯机构：
[Zhou, KC; Deng, ZJ; Wei, QP ] C;Cent South Univ, Sch Mat Sci & Engn, State Key Lab Powder Met, Changsha 410083, Peoples R China.
关键词：
Cu-matrix composite;Diamond skeleton;Gas pressure infiltration;High-efficiency heat transfer
摘要：
The weak interfacial bonding strength between diamond and copper intrinsically restricts the enhancement of the thermal conductivity of diamond particles/copper composites (abbreviated as DP/Cu). This work first proposed the diamond skeleton (DS) as the reinforcement element rather than dispersed diamond particles. The tungsten (W) transition layer (c.a. similar to 300 nm thick) having adequate thermal expansion coefficient was sputtered onto the surface of DS via vacuum evaporation technology, aiming to improve the wettability between diamond and copper and accordingly increase the thermal conductivity of DS/copper composites extruded by gas pressure infiltration technique. The experimental results show that the coated W layer can effectively improve the wettability of the diamond surface and reduce the wettability angle from 108.6 degrees to 13.2 degrees. Raman and XRD spectra show that the W layer can, to a great extent, prevent the graphitization of the diamond surface. SEM and EDX evidence a continuous heat transfer path of DS inside the composites. The thermal conductivity of the DS/Cu composite with low diamond loading of 18.4 vol% reaches 575 W/mK, 43.3% higher than that of pure Cu. Finite element simulations show that DS exhibits excellent heat transfer characteristics, agreeing well with the thermal conductivity simulation results.
期刊：
Scripta Materialia,2024年240:115850 ISSN：1359-6462
通讯作者：
Chen, CS;Song, M
作者机构：
[Chen, Chuansheng; Chen, Jiaxuan] Changsha Univ Sci & Technol, Sch Mat Sci & Engn, Changsha 410114, Hunan, Peoples R China.;[Li, Dan; Liu, Chaoqiang; Song, Miao; Zhang, Xiaoyong; Chen, Jiaxuan; Zhou, Kechao; Niu, Pengda] Cent South Univ, Powder Met Res Inst, Changsha 410083, Hunan, Peoples R China.;[Ma, Xiaolong] City Univ Hong Kong, Dept Mat Sci & Engn, Kowloon, Hong Kong 999077, Peoples R China.;[Zhao, Yunqiang] Guangdong Acad Sci, China Ukraine Inst Welding, Guangdong Prov Key Lab Adv Welding Technol, Guangzhou 510650, Peoples R China.
通讯机构：
[Song, M ; Chen, CS ] C;Changsha Univ Sci & Technol, Sch Mat Sci & Engn, Changsha 410114, Hunan, Peoples R China.;Cent South Univ, Powder Met Res Inst, Changsha 410083, Hunan, Peoples R China.
关键词：
Crack;Titanium alloy;Phase transformation;Transmission electron microscopy (TEM)
摘要：
Designing dual-phase titanium (Ti) alloys with exceptional damage tolerance holds profound scientific and engineering significance. A comprehensive understanding of microstructure evolution around cracks under diverse loading conditions is pivotal in advancing this pursuit. Here, tensile and fatigue cracks were formed quasi in-situ in a dual-phase Ti alloy, and the microstructures around the cracks were systematically analyzed and compared using TEM. Our findings reveal that the deflection of tensile cracks is primarily influenced by the hindrance posed by the straight alpha/beta heterointerfaces and is further facilitated by the beta-to-alpha" martensite transformation within the beta matrix. In contrast, fatigue cracks exhibit deflection within the beta matrix, located far from the alpha lamellae. Furthermore, the presence of spindle-shaped short alpha lamellae holds promise for enhancing resistance to fatigue crack nucleation. These results contribute to fundamental comprehension of the crack nucleation and propagation in dual-phase Ti alloys and provide valuable guidance for materials design.
作者机构：
[Tang, Yu; Huang, Zhi-Yong; Wang, Wei; Huang, Ya-Lan; Liu, Qi; Zhang, Bing-Hao; Ren, Jin-Can; Wang, Xing-Yu; Chen, Bo-Wen] City Univ Hong Kong, Dept Phys, Hong Kong 999077, Peoples R China.;[Lan, Si; Liu, Qi; He, Zhang-Long; He, Hao] City Univ Hong Kong, Shenzhen Res Inst, Shenzhen 518057, Peoples R China.;[He, Hao; He, Zhang-Long] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410114, Peoples R China.
通讯机构：
[Liu, Q ; Liu, Q; He, H ] C;City Univ Hong Kong, Dept Phys, Hong Kong 999077, Peoples R China.;City Univ Hong Kong, Shenzhen Res Inst, Shenzhen 518057, Peoples R China.
关键词：
Lithium-ion batteries;Ni fraction;Extreme fast charging;Structural evolution
摘要：
Lithium-ion batteries (LIBs) with extreme fast charging (XFC) capability are considered an effective way to alleviate range anxiety for electric vehicle (EV) buyers. Owing to the high ionic and electronic conductivity of LiNixCoyMnzO2 (x + y + z = 1, NCM) cathodes, the inevitable Li plating of graphite in NCM | graphite cell is usually identified as a key bottleneck for XFC LIBs. However, the capacity decay mechanism of cathode materials under XFC has not been fully investigated. In this work, three typical NCM cathode materials with different Ni fractions were chosen and their electrochemical performances under XFC associated with structural evolution were investigated. A faster capacity decay of NCMs under XFC conditions is observed, especially for Ni-rich NCMs. In-situ X-ray diffraction (XRD) reveals that the multiple c-axis parameters appear at the high-voltage regions in Ni-rich NCMs, which is probably triggered by the larger obstruction of Li (de)intercalation. Particularly, NCMs with moderate Ni fraction also present a similar trend under XFC conditions. This phenomenon is more detrimental to the structural and morphological stability, resulting in a faster capacity decay than that under low current charging. This work provides new insight into the degradation mechanism of NCMs under XFC conditions, which can promote the development of NCM cathode materials with XFC capability.
摘要：
Significant progress has been made in mitigating membrane biofouling by microbial quorum quenching (QQ). More efficient and survivable QQ strains need to be discovered. A new strain named Bacillus thuringiensis LZX01 was isolated in this study using a low carbon source concentration "starving" method from a membrane bioreactor (MBR). LZX01 secreted intracellular lactonase to enable QQ behavior and was capable of degrading 90% of C8-HSL (200ng/mL) within 30min, which effectively delayed biofouling by inhibiting the growth of bacteria associated with biofouling and improving the hydrophilicity of bound extracellular polymeric substances. As a result, the membrane biofouling rate of MBR adding LZX01 was four times slower than that of the control MBR. Importantly, LZX01 maintains its QQ activity even in environments contaminated with typical toxic pollutants. Therefore, with high efficiency, toxicity resistance, and easy culture, LZX01 holds great potential and significant promise for biofouling control applications.
作者机构：
[Hu, Tao; Zhu, Xinyue; Zhang, Yu; Ma, Yanwen; Han, Xuran; Chen, Jialu; Wu, Qiang; Chen, Zibo; Zhao, Jin; Chen, Jianyu; Wang, Cheng; He, Qian] State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing, 210023, P. R. China;[Yuan, Du] College of Materials Science and Engineering, Changsha University of Science and Technology, Hunan, 410004, P. R. China;[Yang, Lijun] Key Laboratory of Mesoscopic Chemistry of MOE and Jiangsu Provincial Laboratory for Nanotechnology School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China;[Ma, Yanwen] Suzhou Vocational Institute of Industrial Technology, Suzhou, 215104, P. R. China
关键词：
aqueous zinc batteries;intergranular reactions;single (002)-texture;zinc metal anode
摘要：
Rechargeable aqueous zinc batteries are promising but hindered by unfavorable dendrite growth and side reactions on zinc anodes. In this study, we demonstrate a fast melting-solidification approach for effectively converting commercial Zn foils into single (002)-textured Zn featuring millimeter-sized grains. The melting process eliminates initial texture, residual stress, and grain size variations in diverse commercial Zn foils, guaranteeing the uniformity of commercial Zn foils into single (002)-textured Zn. The single (002)-texture ensures large-scale epitaxial and dense Zn deposition, while the reduction in grain boundaries significantly minimizes intergranular reactions. These features enable large grain single (002)-textured Zn shows planar and dense Zn deposition under harsh conditions (100 mA cm(-2) , 100 mAh cm(-2) ), impressive reversibility in Zn||Zn symmetric cell (3280 h under 1 mA cm(-2) , 830 h under 10 mAh cm(-2) ), and long cycling stability over 180 h with a high depth of discharge value of 75 %. This study successfully addresses the issue of uncontrollable texture formation in Zn foils following routine annealing treatments with temperatures below the Zn melting point. The findings of this study establish a highly efficient strategy for fabricating highly reversible single (002)-textured Zn anodes.
摘要：
Metal-based materials are widely regarded as promising catalysts for activating peroxymonosulfate (PMS) to remove refractory organic contaminants with high efficiency. In our study, Ni-Fe layered double hydroxide (LDH)-biochar (BC) composite-induced PMS-based advanced oxidation process (AOP) was utilized to elucidate the degradation of tetracycline hydrochloride (TCH). In Ni-Fe LDH-BC/PMS system, more than 99% TCH (45 mu M) could be removed effectively at low doses of oxidant (PMS, 0.10 mM) and catalyst (Ni-Fe LDH-BC, 0.10 g/L) addition within 80 min. Besides, the Ni-Fe LDH-BC/PMS system showed high resistance to some inorganic anions, and the Ni-Fe LDH-BC composite possessed excellent reusability in the degradation of TCH (>99% in four cyclic experiments). The reaction mechanisms were investigated via electron paramagnetic resonance detection, chemical quenching tests, probe experiments, and electrochemical measurements. These results indicated that the electron-shuttle mechanism played the dominant role in the removal of TCH. It is worth noting that determination of PMS concentration can reflect the reliability of quenching experiments. In the Ni-Fe LDH-BC composite, BC could not only improve the dispersion of Ni-Fe LDH, but also increase the conductivity of Ni-Fe LDH. Overall, a successful modification strategy was proposed in our study to improve the catalytic property of Ni-Fe LDH, and reaction mechanisms of TCH degradation were discussed deeply and comprehensively.
期刊：
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing,2024年890:145889 ISSN：0921-5093
通讯作者：
Zhou, SF;Yang, H;Liu, YJ
作者机构：
[Yi, Yanliang; Li, Kunmao; Zhou, Shengfeng; Jin, Jianbo; Zhou, SF; Yang, Junjie] Jinan Univ, Inst Adv Wear & Corros Resistance & Funct Mat, Guangzhou 510632, Peoples R China.;[Yang, H; Yang, Huan] Shenzhen Technol Univ, Sino German Coll Intelligent Mfg, Shenzhen 518118, Peoples R China.;[Liu, Yujing] Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, 960,2 Sect,Wanjiali RD, Changsha 410004, Hunan, Peoples R China.;[Chen, Dongchu] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 52800, Guangdong, Peoples R China.;[Zhang, Wencai] Jinan Univ, Affiliated Hosp 1, Dept Orthoped, Guangzhou 510632, Peoples R China.
通讯机构：
[Yang, H ] S;[Liu, YJ ] C;[Zhou, SF ] J;Jinan Univ, Inst Adv Wear & Corros Resistance & Funct Mat, Guangzhou 510632, Peoples R China.;Shenzhen Technol Univ, Sino German Coll Intelligent Mfg, Shenzhen 518118, Peoples R China.
关键词：
Laser powder bed fusion (L-PBF);Mechanical properties;Ti2Cu;Tensile strength;Grain boundaries
摘要：
The beta-type Ti35NbxCu alloys (x = 0, 1, 3, 5, and 7 wt%) were produced by laser powder bed fusion (LPBF) and the influence of Cu content on the microstructure and mechanical properties was studied. The results indicate that when the content of Cu is less than 3 wt%, Cu can diffuse completely into the Ti matrix to form solid solution without element segregation. Moreover, the elastic modulus of Ti35Nb1Cu alloy (49.1 +/- 1.6 GPa) is reduced by 33 % compared to that of Ti35Nb alloy (73.2 +/- 1.4 GPa). When the content of Cu exceeds 3 wt%, the eutectoid reaction is activated during the cyclic heating and rapid cooling of LPBF, and the partially supersaturated beta phase is transformed into nano-scale alpha and Ti2Cu phases (beta ->alpha+Ti2Cu). Nano-scale Ti2Cu particles precipitated along beta grain boundary results in a pinning effect, which inhibits the growth of beta grain, hinders dislocation movement, and improves the strength of the alloy. However, when the content of Cu is 7 wt%, the dislocation density (4.179 x 1015 m 2) and the ratio of brittle phase Ti2Cu (8.5 %) are too high, and the stress concentration caused by the initiation of inherent micro-cracks are the main reason for the tensile brittle fracture of Ti35Nb7Cu alloy. As such, the Ti35Nb5Cu alloy has the highest tensile strength of 867.3 +/- 24 MPa and the elongation reaches 11.7 +/- 0.5 %. Therefore, solution strengthening of Cu, fine grain strengthening of beta, dislocation strengthening, and precipitation strengthening of Ti2Cu are the main reasons for the excellent comprehensive mechanical properties of Ti35Nb5Cu alloy.
期刊：
Chemical Engineering Journal,2024年481:148579 ISSN：1385-8947
通讯作者：
Bai, Maohui;Hong, B;Huang, ZM
作者机构：
[Zhang, Libo; Bai, Maohui; Hong, Bo; Lai, Yanqing] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;[Wang, Xuhui; Bai, Maohui] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Huang, ZM; Huang, Zimo] Guangdong Univ Technol, Sch Chem Engn & Light Ind, Inst Sustainable Transformat, Guangzhou 510006, Peoples R China.;[Zhang, Libo; Hong, Bo; Lai, Yanqing] Cent South Univ, Hunan Prov Key Lab Nonferrous Value Added Met, Changsha 410083, Peoples R China.
通讯机构：
[Huang, ZM ] G;[Bai, MH; Hong, B ] C;Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;Guangdong Univ Technol, Sch Chem Engn & Light Ind, Inst Sustainable Transformat, Guangzhou 510006, Peoples R China.
关键词：
Nucleophilic fluorination;Li metal anode;In-situ polymerization;Gel polymer electrolyte
摘要：
The Gel Polymer Electrolyte (GPE) is recognized as a promising alternative to conventional electrolytes, aiming to enhance the longevity and energy density of lithium-ion batteries (LIBs). However, several challenges persist, particularly concerning the conductivity and voltage window of GPE in battery systems. In this study, we introduce an in-situ 3D crosslinked GPE, using polymethyl methacrylate (PMMA) as the monomer and polyethylene glycol dimethacrylate (PEGDMA) as the crosslinking agent, to ensure structural stability and optimized ion conductivity. We also incorporate a potent nucleophilic fluorination agent, Tetrabutylammonium fluoride (TBAF), to augment the compatibility and oxidation resistance of the formulated FGPPE. The recurring (-CH2CH2O-) units of PEGDMA, coupled with in-situ lithium fluoride (LiF) and C-F groups introduced by TBAF, endow the FGPPE with a remarkable ionic conductivity of 7.8 mS cm(-1) and a distinctly electrochemical stability of 4.65 V. Notably, the Li metal anode, featuring an F-rich solid-state interface (SEI), demonstrates uniform Li+ deposition, sustaining a cycling life of 1000 h and maintaining a commendable average coulomb efficiency of 98.5 % over 300 cycles. Additionally, the NCM811/SiC pouch cell integrated with FGPPE showcases superior cycling stability, retaining 99.4 % of its capacity after 600 cycles at an elevated voltage of 4.45 V. Such advancements in gel polymer electrolyte design can significantly expedite the commercial deployment of gel polymer Li-ion batteries.
作者机构：
[Chuangfang Tao; Huanyi Liao; Bin Chen; Weiguo Mao; Zheqiong Fan; Zhe Zhou] College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, China;[Jinglv Zuo] Hunan Boyun New Material Co. Ltd, Changsha 410205, China;[Jie Wang; Cuiying Dai] College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, China<&wdkj&>Hunan Boyun New Material Co. Ltd, Changsha 410205, China
通讯机构：
[Weiguo Mao; Zhe Zhou] C;College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha 410114, China
摘要：
The (PyC-Csf)/ZrB2-SiC-ZrC ceramics are fabricated by reactive spark plasma sintering (RSPS) at 1200 °C. The sample has a low density and intact pyrolytic carbon modified carbon fiber (PyC-Csf). After three cycles of ablation (heat flux = 2.38 MW/m2, t = 120 s), samples demonstrate excellent resistance to oxidative ablation. The mass recession rate and linear recession rate for the sample are 3.41 g/m2∙s and 0.68 µm/s, respectively. Excessive content of carbon destroys the oxide layer by forming large amounts of CO2 during the ablation process. The inner layer of intact PyC-Csf aggregates around the borosilicate which are denser in the oxide layer. Finally, a porous ZrO2-SiO2 layer and a dense ZrO2-SiO2-Csf layer are formed on the surface of the sample which resists ablation.
摘要：
The aging precipitation behavior of super austenitic stainless steels 904L (4.32% Mo), 254SMo (6.06% Mo), and AL-6XN (6.29% Mo) with different Mo contents at 800degree celsius-900degree celsius was investigated by scanning electron microscopy, X-ray diffraction, and transmission electron microscopy, and the effect of Mo content on the sigma-phase precipitation behavior of commonly used super austenitic stainless steels was explored. The effect of Mo content on the sigma-phase precipitation behavior of commonly used super austenitic stainless steel was investigated. The results show that the super austenitic stainless steels with different Mo contents formed different numbers and shapes of sigma-phases in the isothermal aging process, and the number of sigma-phases of 254SMo and AL-6XN is much larger than that of 904L, and the shape of the sigma-phases mainly shows coarse acicularity and elongation, while the sigma-phases of 904L show fine granularity.
摘要：
Cost-effective alkaline water splitting represents a promising and sustainable approach for hydrogen production. However, the prevention of hydrogen/oxygen mixing and the efficient use of unstable renewable energy are challenging issues. Herein, we propose a novel solution involving the integration of a nickel-metal hydride (Ni-MH) battery as a redox mediator and affordable a NiFe LDHs–NiFe alloy gradient hybrid bifunctional catalysts as gas evolution electrodes, effectively decoupling the hydrogen and oxygen evolution processes during water splitting. Then, the hydrogen evolution reaction (HER) cell using hydrogen storage alloy and catalytic electrode only requires 0.28 V and the oxygen evolution reaction (OER) cell using nickel hydroxide and catalytic electrode only requires 0.25 V to reach a high current density of 100 mA cm−2. Furthermore, a NiOOH-Zn cell is introduced as an alternative, replacing the OER reaction with Zn. This NiOOH-Zn cell can be discharged without further energy input. Moreover, such a decoupled water electrolysis system can seamlessly integrate with a Ni-MH battery, providing the flexibility to efficiently convert renewable energy sources into both hydrogen and electricity. This integrated system maximizes the utilization of renewable energy, making a significant contribution to sustainable energy production.
摘要：
Given the merits of affordable cost, superior low-temperature performance, and advanced safe properties, sodium-ion batteries (SIBs) have exhibited great development potential in large scale energy storage applications. Among various emerging carbonaceous anode materials applied for SIBs, hard carbon (HC) has recently gained significant attention regarding their relatively low cost, wide availability, and optimal overall performance. However, the insufficient initial Coulombic efficiency (ICE) of HC is the main bottlenecks, which is inevitably hindering their further commercial applications. Herein, an in-depth holistic exposition about the reasons causing the unsatisfied ICE and the recent advances on effective improvement strategies are comprehensively summarized in this review, which have been divided into two aspects including the intrinsic property (degree of graphitization, pore structure, defect, et al.) and the extrinsic factor (electrolyte, electrode materials, et al.). In addition, future prospects and perspectives on HC to enable practical application in SIBs are also briefly outlined.
摘要：
The mechano‐electrochemical coupling behavior of a CFx cathode is investigated by in situ monitoring the dynamic evolution of strain/stress using a digital image correlation technique, electrochemical methods, and theoretical equations. The structure‐ and rate‐dependent mechano‐electrochemical coupling behaviors and discharge mechanisms of the CFx cathodes are investigated for the development of high‐power Li/CFx batteries. Abstract Unclear reaction mechanisms and unsatisfactory power performance hinder the further development of advanced lithium/fluorinated carbon (Li/CFx) batteries. Herein, the mechano‐electrochemical coupling behavior of a CFx cathode is investigated by in situ monitoring strain/stress using digital image correlation (DIC) techniques, electrochemical methods, and theoretical equations. The DIC monitoring results present the distribution and dynamic evolution of the plane strain and indicate strong dependence toward the material structure and discharge rate. The average plane principal strain of fully discharged 2D fluorinated graphene nanosheets (FGNSs) at 0.5 C is 0.50%, which is only 38.5% that of conventional bulk‐structure CFx. Furthermore, the superior structural stability of the FGNSs is demonstrated by the microstructure and component characterization before and after discharge. The plane stress evolution is calculated based on theoretical equations, and the contributions of electrochemical and mechanical factors are examined and discussed. Subsequently, a structure‐dependent three‐region discharge mechanism for CFx electrodes is proposed from a mechanical perspective. Additionally, the surface deformation of Li/FGNSs pouch cells formed during the discharge process is monitored using in situ DIC. This study reveals the discharge mechanism of Li/CFx batteries and facilitates the design of advanced CFx materials.
通讯机构：
[Zou, GQ ; Xiong, Y] C;Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Zinc anodes;N 4 sites;Overpotential;Single atom vacancy;Zn-N 4 bonds
摘要：
Zn metal has delivered great promise as anode material for grid -level energy storage yet is challenged by dendrite growth. However, the overpotential, another important factor for energy conversion efficiency has been often overlooked, making the design of zincophilic substrates to guide the uniform deposition of Zn2+ with low overpotential are full of challenges. Here, inspired by density functional theory (DFT) that the N4 sites created by single atom vacancy with large binding energy with Zn2+ can induce the Zn2+ to form Zn-N4 bonds, according well with the electrochemical results that the Zn2+ can be reintroduced back into the electrolyte, demonstrating that the process is highly reversible. Extended X-ray absorption fine structure (EXAFS) combined with electron paramagnetic resonance (EPR) analysis certified the coexistence of both stable Zn-N4 sites and cation vacancies with high density in single atom Zn supported on nitrogen doped carbon materials (SA-Zn/CN-1). Most impressively, the SA-Zn/CN-1@Zn anode exhibits remarkable cycling stability at 1 mA cm -2 for over 3300 h with the ultra -low overpotential of about 22 mV in symmetric cells and a considerable capacity retention of 82% after 10000 cycles in capacitors assembled with active carbon. In a word, this work suggests a new approach to inhibit the growth of zinc dendrites with low overpotential through high reversible N4 sites provided by single atom vacancy engineering, which may be extended to inhibit other metal dendrites in the future.
期刊：
Materials Science in Semiconductor Processing,2024年174:108186 ISSN：1369-8001
通讯作者：
Jianlin Chen
作者机构：
[Jianlin Chen; Zihan Wu; Shu Chen; Wei Zhao; Yu Zhang; Wenxia Ye; Ruoxi Yang; Zhuoyin Peng; Jian Chen] School of Energy & Power Engineering, Changsha University of Science and Technology, Changsha, 410114, China;[Li Gong] School of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114, China
通讯机构：
[Jianlin Chen] S;School of Energy & Power Engineering, Changsha University of Science and Technology, Changsha, 410114, China
摘要：
Zinc oxide nanorod arrays (ZnO NRAs) have been previously introduced as electron transport layer (ETL) of perovskite solar cells (PSCs) due to their high electron mobility and unique textured morphology. However, the presence of hydroxyl and oxygen vacancies on the surface of bare intrinsic ZnO NRAs may act as defect centers leading to carrier nonradiative recombination and the device photovoltaic performance degradation. Here, we propose a mutilayer SnO2/Al-doped ZnO nanorod arrays/SnO2 (SnO2/AZO NRAs/SnO2) composite to be utilized as ETL of all-inorganic CsPbBr3 PSCs. The influence of AZO NRAs with various Al ion (Al3+) doping content on the performance of CsPbBr3 PSCs was explored. The hole-free carbon-based CsPbBr3 PSCs with an architecture of FTO/SnO2/AZO NRAs/SnO2/CsPbBr3/carbon based on 1 at% AZO NRAs exhibited the best photovoltaic performance with a champion power conversion efficiency (PCE) of 7.11 %, open-circuit voltage (Voc) of 1.46 V, short-circuit current density (Jsc) of 6.88 mA/cm2, and fill factor (FF) of 71.1 %, compared with the bare intrinsic ZnO-based counterpart with a PCE of 3.45 %, Voc of 0.80 V, Jsc of 8.46 mA/cm2, and FF of 51 %, respectively. The photovoltaic performance enhancement can be atrributed to enhanced light collection and electron extraction capability, with lower open-circuit voltage loss and more suitable interface band alighment. It is notable that the AZO NRAs were prepared by a facile electrodeposition approach to obtain large-area textured ETLs. This strategy may also be applicable to the photovoltaic performance improvemet of all types of PSCs.
摘要：
In this work, a Cu@Co catalyst with dilatation strain is prepared for low‐concentration NO electroreduction, and it exhibits high NH3 yield of 627.20 µg h‐1 cm‐2 and Faradaic efficiency of 76.54%. The assembled Zn‐NO battery using Cu@Co as cathode achieves a power density of 3.08 mW cm−2, which can simultaneously realize NO removal, NH3 green synthesis, and electricity output. Abstract Electrocatalytic reduction of nitric oxide (NO) to ammonia (NH3) is a clean and sustainable strategy to simultaneously remove NO and synthesize NH3. However, the conversion of low concentration NO to NH3 is still a huge challenge. In this work, the dilatation strain between Cu and Co interface over Cu@Co catalyst is built up and investigated for electroreduction of low concentration NO (volume ratio of 1%) to NH3. The catalyst shows a high NH3 yield of 627.20 µg h−1 cm−2 and a Faradaic efficiency of 76.54%. Through the combination of spherical aberration‐corrected transmission electron microscopy and geometric phase analyses, it shows that Co atoms occupy Cu lattice sites to form dilatation strain in the xy direction within Co region. Further density functional theory calculations and NO temperature‐programmed desorption (NO‐TPD) results show that the surface dilatation strain on Cu@Co is helpful to enhance the NO adsorption and reduce energy barrier of the rate‐determining step (*NO to *NOH), thereby accelerating the catalytic reaction. To simultaneously realize NO exhaust gas removal, NH3 green synthesis, and electricity output, a Zn‐NO battery with Cu@Co cathode is assembled with a power density of 3.08 mW cm−2 and an NH3 yield of 273.37 µg h−1 cm−2.
