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高容量储氢材料的研究进展 总被引:6,自引:0,他引:6
氢能是一种理想的二次能源.氢能开发和利用需要解决氢的制取、储存和利用3个问题,而氢的规模储运是现阶段氢能应用的瓶颈.氢的储存方法有高压气态储存、低温液态储存和固态储存等3种.固态储氢材料储氢是通过化学反应或物理吸附将氢气储存于固态材料中,其能量密度高且安全性好,被认为是最有发展前景的一种氖气储存方式.由轻元素构成的轻质高容量储氢材料,如硼氢化物、铝氢化物、氨摹氢化物等,理论储氢容量均达到5%(质量分数)以上,这为固态储氢材料与技术的突破带来了希望.新型储氢材料未来研究的重点将集中于高储氢容量、近室温操作、可控吸/放氢、长寿命的轻金属基氢化物材料与体系. 相似文献
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Solvent‐Free Synthesis of Uniform MOF Shell‐Derived Carbon Confined SnO2/Co Nanocubes for Highly Reversible Lithium Storage 下载免费PDF全文
Qiu He Jinshuai Liu Zhaohuai Li Qi Li Lin Xu Baoxuan Zhang Jiashen Meng Yuzhu Wu Liqiang Mai 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(37)
Tin dioxide (SnO2) has attracted much attention in lithium‐ion batteries (LIBs) due to its abundant source, low cost, and high theoretical capacity. However, the large volume variation, irreversible conversion reaction limit its further practical application in next‐generation LIBs. Here, a novel solvent‐free approach to construct uniform metal–organic framework (MOF) shell‐derived carbon confined SnO2/Co (SnO2/Co@C) nanocubes via a two‐step heat treatment is developed. In particular, MOF‐coated CoSnO3 hollow nanocubes are for the first time synthesized as the intermediate product by an extremely simple thermal solid‐phase reaction, which is further developed as a general strategy to successfully obtain other uniform MOF‐coated metal oxides. The as‐synthesized SnO2/Co@C nanocubes, when tested as LIB anodes, exhibit a highly reversible discharge capacity of 800 mAh g?1 after 100 cycles at 200 mA g?1 and excellent cycling stability with a retained capacity of 400 mAh g?1 after 1800 cycles at 5 A g?1. The experimental analyses demonstrate that these excellent performances are mainly ascribed to the delicate structure and a synergistic effect between Co and SnO2. This facile synthetic approach will greatly contribute to the development of functional metal oxide‐based and MOF‐assisted nanostructures in many frontier applications. 相似文献
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Yanran Wang Xiaowei Chen Hongyu Zhang Guanglin Xia Dalin Sun Xuebin Yu 《Advanced materials (Deerfield Beach, Fla.)》2020,32(31):2002647
Hydrogen storage is a vital technology for developing on-board hydrogen fuel cells. While Mg(BH4)2 is widely regarded as a promising hydrogen storage material owing to its extremely high gravimetric and volumetric capacity, its poor reversibility poses a major bottleneck inhibiting its practical applications. Herein, a facile strategy to effectively improve the reversible hydrogen storage performance of Mg(BH4)2 via building heterostructures uniformly inside MgH2 nanoparticles is reported. The in situ reaction between MgH2 nanoparticles and B2H6 not only forms homogeneous heterostructures with controllable particle size but also simultaneously decreases the particle size of the MgH2 nanoparticles inside, which effectively reduces the kinetic barrier that inhibits the reversible hydrogen storage in both Mg(BH4)2 and MgH2. More importantly, density functional theory coupled with ab initio molecular dynamics calculations clearly demonstrates that MgH2 in this heterostructure can act as a hydrogen pump, which drastically changes the enthalpy for the initial formation of B H bonds by breaking stable B B bonds from endothermic to exothermic and hence thermodynamically improves the reversibility of Mg(BH4)2. It is believed that building heterostructures provides a window of opportunity for discovering high-performance hydrogen storage materials for on-board applications. 相似文献
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2D Film of Carbon Nanofibers Elastically Astricted MnO Microparticles: A Flexible Binder‐Free Anode for Highly Reversible Lithium Ion Storage 下载免费PDF全文
Ting Wang Hangang Li Shaojun Shi Ting Liu Gang Yang Yimin Chao Fan Yin 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(20)
MnO as anode materials has received particular interest owing to its high specific capacity, abundant resources, and low cost. However, serious problems related to the large volume change (>170%) during the lithiation/delithiation processes still results in poor rate capability and fast capacity decay. With homogenous crystals of MnO grown in the network of carbon nanofibers (CNF), binding effect of CNF can effectively weaken the volume change of MnO during cycles. In this work, a CNF/MnO flexible electrode for lithium‐ion batteries is designed and synthesized. The CNF play the roles of conductive channel and elastically astricting MnO particles during lithiation/delithiation. CNF/MnO as binder‐free anode delivers specific capacity of 983.8 mAh g?1 after 100th cycle at a current density of 0.2 A g?1, and 600 mAh g?1 at 1 A g?1 which are much better than those of pure MnO and pure CNF. The ex‐situ morphologies clearly show the relative volume change of MnO/CNF as anode under various discharging and charging times. CNF can elastically buffer the volume change of MnO during charging/discharging cycles. A facile and scalable approach for synthesizing a novel flexible binder‐free anode of CNF/MnO for potential application in highly reversible lithium storage devices is presented. 相似文献
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硼氢化锂(LiBH4)因其高达18.4wt%的含氢量而被用于贮氢材料的研究.但LiBH4放氢和再氢化温度较高,因此如何使其去稳定化(destabilization)从而降低其放氢温度成为研究的热点之一.本文报告了金属硼化物MB2 (M=Mg,Ti,Zr)和MB6 (M=Ca,La)对LiBH4的去稳定化作用.MB2的添加使LiBH4的放氢温度从450℃降低至350℃,而MB6对LiBH4放氢温度的降低作用更大;而且这些金属硼化物还能有效促进LiBH4放氢后的再氢化反应.XRD,FT-IR,DSC和MS等分析结果表明,金属硼化物在LiBH4的首次放氢过程中起着催化剂的作用,并参与随后的再氢化反应. 相似文献
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Metal Hydride Nanoparticles with Ultrahigh Structural Stability and Hydrogen Storage Activity Derived from Microencapsulated Nanoconfinement 下载免费PDF全文
Jiguang Zhang Yunfeng Zhu Huaijun Lin Yana Liu Yao Zhang Shenyang Li Zhongliang Ma Liquan Li 《Advanced materials (Deerfield Beach, Fla.)》2017,29(24)
Metal hydrides (MHs) have recently been designed for hydrogen sensors, switchable mirrors, rechargeable batteries, and other energy‐storage and conversion‐related applications. The demands of MHs, particular fast hydrogen absorption/desorption kinetics, have brought their sizes to nanoscale. However, the nanostructured MHs generally suffer from surface passivation and low aggregation‐resisting structural stability upon absorption/desorption. This study reports a novel strategy named microencapsulated nanoconfinement to realize local synthesis of nano‐MHs, which possess ultrahigh structural stability and superior desorption kinetics. Monodispersed Mg2NiH4 single crystal nanoparticles (NPs) are in situ encapsulated on the surface of graphene sheets (GS) through facile gas–solid reactions. This well‐defined MgO coating layer with a thickness of ≈3 nm efficiently separates the NPs from each other to prevent aggregation during hydrogen absorption/desorption cycles, leading to excellent thermal and mechanical stability. More interestingly, the MgO layer shows superior gas‐selective permeability to prevent further oxidation of Mg2NiH4 meanwhile accessible for hydrogen absorption/desorption. As a result, an extremely low activation energy (31.2 kJ mol–1) for the dehydrogenation reaction is achieved. This study provides alternative insights into designing nanosized MHs with both excellent hydrogen storage activity and thermal/mechanical stability exempting surface modification by agents. 相似文献
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Cheng Yang Yu Yao Yuebin Lian Yujie Chen Rahim Shah Xiaohui Zhao Muzi Chen Yang Peng Zhao Deng 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(16)
Transition metal oxides (TMOs) are regarded as promising candidates for anodes of lithium ion batteries, but their applications have been severely hindered by poor material conductivity and lithiated volume expansion. As a potential solution, herein is presented a facile approach, by electrospinning a manganese‐based metal organic framework (Mn‐MOF), to fabricate yolk–shell MnOx nanostructures within carbon nanofibers in a botryoid morphology. While the yolk–shell structure accomodates the lithiated volume expansion of MnOx, the fiber confinement ensures the structural integrity during charge/discharge, achieving a so‐called double‐buffering for cyclic volume fluctuation. The formation mechanism of the yolk–shell structure is well elucidated through comprehensive instrumental characterizations and cogitative control experiments, following a combined Oswald ripening and Kirkendall process. Outstanding electrochemical performances are demonstrated with prolonged stability over 1000 cycles, boosted by the double‐buffering design, as well as the “breathing” effect of lithiation/delithiation witnessed by ex situ imaging. Both the fabrication methodology and electrochemical understandings gained here for nanostructured MnOx can also be extended to other TMOs toward their ultimate implementation in high‐performance lithium ion batteries (LIBs). 相似文献
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Dual‐Layered Film Protected Lithium Metal Anode to Enable Dendrite‐Free Lithium Deposition 下载免费PDF全文
Chong Yan Xin‐Bing Cheng Yang Tian Xiang Chen Xue‐Qiang Zhang Wen‐Jun Li Jia‐Qi Huang Qiang Zhang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(25)
Lithium metal batteries (such as lithium–sulfur, lithium–air, solid state batteries with lithium metal anode) are highly considered as promising candidates for next‐generation energy storage systems. However, the unstable interfaces between lithium anode and electrolyte definitely induce the undesired and uncontrollable growth of lithium dendrites, which results in the short‐circuit and thermal runaway of the rechargeable batteries. Herein, a dual‐layered film is built on a Li metal anode by the immersion of lithium plates into the fluoroethylene carbonate solvent. The ionic conductive film exhibits a compact dual‐layered feature with organic components (ROCO2Li and ROLi) on the top and abundant inorganic components (Li2CO3 and LiF) in the bottom. The dual‐layered interface can protect the Li metal anode from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite‐free Li metal anode. This work demonstrates the concept of rational construction of dual‐layered structured interfaces for safe rechargeable batteries through facile surface modification of Li metal anodes. This not only is critically helpful to comprehensively understand the functional mechanism of fluoroethylene carbonate but also affords a facile and efficient method to protect Li metal anodes. 相似文献