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1.
Formation of N‐Doped Carbon‐Coated ZnO/ZnCo2O4/CuCo2O4 Derived from a Polymetallic Metal–Organic Framework: Toward High‐Rate and Long‐Cycle‐Life Lithium Storage 下载免费PDF全文
Ji‐Liang Niu Cheng‐Hui Zeng Hai‐Jun Peng Xiao‐Ming Lin Palanivel Sathishkumar Yue‐Peng Cai 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(47)
Metal–organic frameworks (MOFs) are very promising self‐sacrificing templates for the large‐scale fabrication of new functional materials owing to their versatile functionalities and tunable porosities. Most conventional metal oxide electrodes derived from MOFs are limited by the low abundance of incorporated metal elements. This study reports a new strategy for the synthesis of multicomponent active metal oxides by the pyrolysis of polymetallic MOF precursors. A hollow N‐doped carbon‐coated ZnO/ZnCo2O4/CuCo2O4 nanohybrid is prepared by the thermal annealing of a polymetallic MOF with ammonium bicarbonate as a pore‐forming agent. This is the first report on the rational design and preparation of a hybrid composed of three active metal oxide components originating from MOF precursors. Interestingly, as a lithium‐ion battery anode, the developed electrode delivers a reversible capacity of 1742 mAh g?1 after 500 cycles at a current density of 0.3 mA g?1. Furthermore, the material shows large storage capacities (1009 and 667 mAh g?1), even at high current flow (3 and 10 A g?1). The remarkable high‐rate capability and outstanding long‐life cycling stability of the multidoped metal oxide benefits from the carbon‐coated integrated nanostructure with a hollow interior and the three active metal oxide components. 相似文献
2.
Chengzhan Yan Huaping Zhao Jun Li Huile Jin Long Liu Wanyi Wu Jichang Wang Yong Lei Shun Wang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(11)
The high theoretical capacity of red phosphorus (RP) makes it a promising anode material for lithium‐ion batteries. However, the large volume change of RP during charging/discharging imposes an adverse effect on the cyclability and the rate performance suffers from its low conductivity. Herein, a facile solution‐based strategy is exploited to incorporate phosphorus into the pores of zeolitic imidazole framework (ZIF‐8) derived carbon hosts under a mild temperature. With this method, the blocky RP is etched into the form of polyphosphides anions (PP, mainly P5?) so that it can easily diffuse into the pores of porous carbon hosts. Especially, the indelible crystalline surface phosphorus can be effectively avoided, which usually generates in the conventional vapor‐condensation encapsulation method. Moreover, highly‐conductive ZIF‐8 derived carbon hosts with any pore smaller than 3 nm are efficient for loading PP and these pores can alleviate the volume change well. Finally, the composite of phosphorus encapsulated into ZIF‐8 derived porous carbon exhibits a significantly improved electrochemical performance as lithium‐ion battery anode with a high capacity of 786 mAh g?1 after 100 cycles at 0.1 A g?1, a good stability within 700 cycles at 1 A g?1, and an excellent rate performance. 相似文献
3.
Yolk–Shell MnO@ZnMn2O4/N–C Nanorods Derived from α‐MnO2/ZIF‐8 as Anode Materials for Lithium Ion Batteries 下载免费PDF全文
Ming Zhong Donghui Yang Chenchao Xie Zhang Zhang Zhen Zhou Xian‐He Bu 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(40):5564-5571
Manganese oxides (MnOx) are promising anode materials for lithium ion batteries, but they generally exhibit mediocre performances due to intrinsic low ionic conductivity, high polarization, and poor stability. Herein, yolk–shell nanorods comprising of nitrogen‐doped carbon (N–C) coating on manganese monoxide (MnO) coupled with zinc manganate (ZnMn2O4) nanoparticles are manufactured via one‐step carbonization of α‐MnO2/ZIF‐8 precursors. When evaluated as anodes for lithium ion batteries, MnO@ZnMn2O4/N–C exhibits an reversible capacity of 803 mAh g?1 at 50 mA g?1 after 100 cycles, excellent cyclability with a capacity of 595 mAh g?1 at 1000 mAg?1 after 200 cycles, as well as better rate capability compared with those non‐N–C shelled manganese oxides (MnOx). The outstanding electrochemical performance is attributed to the unique yolk–shell nanorod structure, the coating effect of N–C and nanoscale size. 相似文献
4.
Confined Amorphous Red Phosphorus in MOF‐Derived N‐Doped Microporous Carbon as a Superior Anode for Sodium‐Ion Battery 下载免费PDF全文
Weihan Li Shuhe Hu Xiangyu Luo Zhongling Li Xizhen Sun Minsi Li Fanfan Liu Yan Yu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(16)
Red phosphorus (P) has attracted intense attention as promising anode material for high‐energy density sodium‐ion batteries (NIBs), owing to its high sodium storage theoretical capacity (2595 mAh g?1). Nevertheless, natural insulating property and large volume variation of red P during cycling result in extremely low electrochemical activity, leading to poor electrochemical performance. Herein, the authors demonstrate a rational strategy to improve sodium storage performance of red P by confining nanosized amorphous red P into zeolitic imidazolate framework‐8 (ZIF‐8) ‐derived nitrogen‐doped microporous carbon matrix (denoted as P@N‐MPC). When used as anode for NIBs, the P@N‐MPC composite displays a high reversible specific capacity of ≈600 mAh g?1 at 0.15 A g?1 and improved rate capacity (≈450 mAh g?1 at 1 A g?1 after 1000 cycles with an extremely low capacity fading rate of 0.02% per cycle). The superior sodium storage performance of the P@N‐MPC is mainly attributed to the novel structure. The N‐doped porous carbon with sub‐1 nm micropore facilitates the rapid diffusion of organic electrolyte ions and improves the conductivity of the encapsulated red P. Furthermore, the porous carbon matrix can buffer the volume change of red P during repeat sodiation/desodiation process, keeping the structure intact after long cycle life. 相似文献
5.
Yuyang Yi Wen Zhao Zhihan Zeng Chaohui Wei Chen Lu Yuanlong Shao Wenyue Guo Shixue Dou Jingyu Sun 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(7)
Potassium ion batteries (KIB) have become a compelling energy‐storage system owing to their cost effectiveness and the high abundance of potassium in comparison with lithium. However, its practical applications have been thwarted by a series of challenges, including marked volume expansion and sluggish reaction kinetics caused by the large radius of potassium ions. In line with this, the exploration of reliable anode materials affording high electrical conductivity, sufficient active sites, and structural robustness is the key. The synthesis of ZIF‐8@ZIF‐67 derived nitrogen‐doped porous carbon confined CoP polyhedron architectures (NC@CoP/NC) to function as innovative KIB anode materials is reported. Such composites enable an outstanding rate performance to harvest a capacity of ≈200 mAh g?1 at 2000 mA g?1. Additionally, a high cycling stability can be gained by maintaining a high capacity retention of 93% after 100 cycles at 100 mA g?1. Furthermore, the potassium ion storage mechanism of the NC@CoP/NC anode is systematically probed through theoretical simulations and experimental characterization. This contribution may offer an innovative and feasible route of emerging anode design toward high performance KIBs. 相似文献
6.
Xi Zhao Hai Xu Zengyu Hui Yue Sun Chenyang Yu Jialu Xue Ruicong Zhou Lumin Wang Henghan Dai Yue Zhao Jian Yang Jinyuan Zhou Qiang Chen Gengzhi Sun Wei Huang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(47)
As an essential member of 2D materials, MXene (e.g., Ti3C2Tx) is highly preferred for energy storage owing to a high surface‐to‐volume ratio, shortened ion diffusion pathway, superior electronic conductivity, and neglectable volume change, which are beneficial for electrochemical kinetics. However, the low theoretical capacitance and restacking issues of MXene severely limit its practical application in lithium‐ion batteries (LIBs). Herein, a facile and controllable method is developed to engineer 2D nanosheets of negatively charged MXene and positively charged layered double hydroxides derived from ZIF‐67 polyhedrons into 3D hollow frameworks via electrostatic self‐assembling. After thermal annealing, transition metal oxides (TMOs)@MXene (CoO/Co2Mo3O8@MXene) hollow frameworks are obtained and used as anode materials for LIBs. CoO/Co2Mo3O8 nanosheets prevent MXene from aggregation and contribute remarkable lithium storage capacity, while MXene nanosheets provide a 3D conductive network and mechanical robustness to facilitate rapid charge transfer at the interface, and accommodate the volume expansion of the internal CoO/Co2Mo3O8. Such hollow frameworks present a high reversible capacity of 947.4 mAh g?1 at 0.1 A g?1, an impressive rate behavior with 435.8 mAh g?1 retained at 5 A g?1, and good stability over 1200 cycles (545 mAh g?1 at 2 A g?1). 相似文献
7.
Amorphous Red Phosphorus Embedded in Sandwiched Porous Carbon Enabling Superior Sodium Storage Performances 下载免费PDF全文
Ying Wu Zheng Liu Xiongwu Zhong Xiaolong Cheng Zhuangjun Fan Yan Yu 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(12)
The red P anode for sodium ion batteries has attracted great attention recently due to the high theoretical capacity, but the poor intrinsic electronic conductivity and large volume expansion restrain its widespread applications. Herein, the red P is successfully encapsulated into the cube shaped sandwich‐like interconnected porous carbon building (denoted as P@C‐GO/MOF‐5) via the vaporization–condensation method. Superior cycling stability (high capacity retention of about 93% at 2 A g?1 after 100 cycles) and excellent rate performance (502 mAh g?1 at 10 A g?1) can be obtained for the P@C‐GO/MOF‐5 electrode. The superior electrochemical performance can be ascribed to the successful incorporation of red P into the unique carbon matrix with large surface area and pore volume, interconnected porous structure, excellent electronic conductivity and superior structural stability. 相似文献
8.
Dong Cai Mengjie Lu La Li Junming Cao Duo Chen Haoran Tu Junzhi Li Wei Han 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(44)
Lithium–sulfur (Li–S) batteries have been considered as one of the most promising energy storage systems owing to their high theoretical capacity and energy density. However, their commercial applications are obstructed by sluggish reaction kinetics and rapid capacity degradation mainly caused by polysulfide shuttling. Herein, the first attempt to utilize a highly conductive metal–organic framework (MOF) of Ni3(HITP)2 graphene analogue as the sulfur host material to trap and transform polysulfides for high‐performance Li–S batteries is made. Besides, the traditional conductive additive acetylene black is replaced by carbon nanotubes to construct matrix conduction networks for triggering the rate and cycling performance of the active cathode. As a result, the S@Ni3(HITP)2 with sulfur content of 65.5 wt% shows excellent sulfur utilization, rate performance, and cyclic durability. It delivers a high initial capacity of 1302.9 mAh g?1 and good capacity retention of 848.9 mAh g?1 after 100 cycles at 0.2 C. Highly reversible discharge capacities of 807.4 and 629.6 mAh g?1 are obtained at 0.5 and 1 C for 150 and 300 cycles, respectively. Such kinds of pristine MOFs with high conductivity and abundant polar sites reveal broad promising prospect for application in the field of high‐performance Li–S batteries. 相似文献
9.
Xu Xiao Hao Wang Weizhai Bao Patrick Urbankowski Long Yang Yao Yang Kathleen Maleski Linfan Cui Simon J. L. Billinge Guoxiu Wang Yury Gogotsi 《Advanced materials (Deerfield Beach, Fla.)》2019,31(33)
The synthesis of low‐dimensional transition metal nitride (TMN) nanomaterials is developing rapidly, as their fundamental properties, such as high electrical conductivity, lead to many important applications. However, TMN nanostructures synthesized by traditional strategies do not allow for maximum conductivity and accessibility of active sites simultaneously, which is a crucial factor for many applications in plasmonics, energy storage, sensing, and so on. Unique interconnected two‐dimensional (2D) arrays of few‐nanometer TMN nanocrystals not only having electronic conductivity in‐plane, but also allowing transport of ions and electrolyte through the porous nanosheets, which are obtained by topochemical synthesis on the surface of a salt template, are reported. As a demonstration of their application in a lithium–sulfur battery, it is shown that 2D arrays of several nitrides can achieve a high initial capacity of >1000 mAh g?1 at 0.2 C and only about 13% degradation over 1000 cycles at 1 C under a high areal sulfur loading (>5 mg cm?2). 相似文献
10.
Liuqian Yang Zhen Cao Jian Yin Chunyan Wang Dandan Ouyang Hui Zhu Yanan Wang Luigi Cavallo Husam N. Alshareef Jiao Yin 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(20):2300440
Nitrogen doping is an effective strategy to improve potassium ion storage of carbon electrodes via the creation of adsorption sites. However, various undesired defects are often uncontrollably generated during the doping process, limiting doping effect on capacity enhancement and deteriorating the electric conductivity. Herein, boron element is additionally introduced to construct 3D interconnected B, N co-doped carbon nanosheets to remedy these adverse effects. This work demonstrates that boron incorporation preferentially converts pyrrolic N species into B N sites with lower adsorption energy barrier, further enhancing the capacity of B, N co-doped carbon. Meanwhile, the electric conductivity is modulated via the conjugation effect between the electron-rich N and electron-deficient B, accelerating the charge-transfer kinetics of potassium ions. The optimized samples deliver a high specific capacity, high rate capability, and long-term cyclic stability (532.1 mAh g−1 at 0.05 A g−1, 162.6 mAh g−1 at 2 A g−1 over 8000 cycles). Furthermore, hybrid capacitors using the B, N co-doped carbon anode deliver a high energy and power density with excellent cycle life. This study demonstrates a promising approach using B N sites for adsorptive capacity and electric conductivity enhancement in carbon materials for electrochemical energy storage applications. 相似文献
11.
Changmiao Chen Yincai Yang Xuan Tang Renhua Qiu Shuangyin Wang Guozhong Cao Ming Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(10)
Developing low cost, long life, and high capacity rechargeable batteries is a critical factor towards developing next‐generation energy storage devices for practical applications. Therefore, a simple method to prepare graphene‐coated FeS2 embedded in carbon nanofibers is employed; the double protection from graphene coating and carbon fibers ensures high reversibility of FeS2 during sodiation/desodiation and improved conductivity, resulting in high rate capacity and long‐term life for Na+ (305.5 mAh g?1 at 3 A g?1 after 2450 cycles) and K+ (120 mAh g?1 at 1 A g?1 after 680 cycles) storage at room temperature. Benefitting from the enhanced conductivity and protection on graphene‐encapsulated FeS2 nanoparticles, the composites exhibit excellent electrochemical performance under low temperature (0 and ?20 °C), and temperature tolerance with stable capacity as sodium‐ion half‐cells. The Na‐ion full‐cells based on the above composites and Na3V2(PO4)3 can afford reversible capacity of 95 mAh g?1 at room temperature. Furthermore, the full‐cells deliver promising discharge capacity (50 mAh g?1 at 0 °C, 43 mAh g?1 at ?20 °C) and high energy density at low temperatures. Density functional theory calculations imply that graphene coating can effectively decrease the Na+ diffusion barrier between FeS2 and graphene heterointerface and promote the reversibility of Na+ storage in FeS2, resulting in advanced Na+ storage properties. 相似文献
12.
Qingyong Wang Yumei Luo Ruizuo Hou Shahid Zaman Kai Qi Hongfang Liu Ho Seok Park Bao Yu Xia 《Advanced materials (Deerfield Beach, Fla.)》2019,31(51)
The development of efficient electrode materials is a cutting‐edge approach for high‐performance energy storage devices. Herein, an effective chemical redox approach is reported for tuning the crystalline and electronic structures of bimetallic cobalt/nickel–organic frameworks (Co‐Ni MOFs) to boost faradaic redox reaction for high energy density. The as‐obtained cobalt/nickel boride/sulfide exhibits a high specific capacitance (1281 F g?1 at 1 A g?1), remarkable rate performance (802.9 F g?1 at 20 A g?1), and outstanding cycling stability (92.1% retention after 10 000 cycles). An energy storage device fabricated with a cobalt/nickel boride/sulfide electrode exhibits a high energy density of 50.0 Wh kg?1 at a power density of 857.7 W kg?1, and capacity retention of 87.7% (up to 5000 cycles at 12 A g?1). Such an effective redox approach realizes the systematic electronic tuning that activates the fast faradaic reactions of the metal species in cobalt/nickel boride/sulfide which may shed substantial light on inspiring MOFs and their derivatives for energy storage devices. 相似文献
13.
Ruiqing Liu Zhiwei Liu Wenhui Liu Yuejiao Liu Xiujing Lin Yi Li Pan Li Zhendong Huang Xiaomiao Feng Leshu Yu Dan Wang Yanwen Ma Wei Huang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(29)
Metal organic frameworks (MOFs)‐derived porous carbon is proposed as a promising candidate to develop novel, tailorable structures as polysulfides immobilizers for lithium–sulfur batteries because of their high‐efficiency electron conductive networks, open ion channels, and abundant central ions that can store a large amount of sulfur and trap the easily soluble polysulfides. However, most central ions in MOFs‐derived carbon framework are encapsulated in the carbon matrix so that their exposures as active sites to adsorb polysulfides are limited. To resolve this issue, highly dispersed TiO2 nanoparticles are anchored into the cobalt‐containing carbon polyhedras that are converted from ZIF‐67. Such a type of TiO2 and Co nanoparticles‐decorated carbon polyhedras (C? Co/TiO2) provide more exposed active sites and much stronger chemical trapping for polysulfides, hence improving the sulfur utilization and enhancing reaction kinetics of sulfur‐containing cathode simultaneously. The sulfur‐containing carbon polyhedras decorated with TiO2 nanoparticles (S@C? Co/TiO2) show a significantly improved cycling stability and rate capability, and deliver a discharge capacity of 32.9% higher than that of TiO2‐free S@C? Co cathode at 837.5 mA g?1 after 200 cycles. 相似文献
14.
Shipeng Zhang Gang Wang Zelei Zhang Beibei Wang Jintao Bai Hui Wang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(14)
The lithium and sodium storage performances of SnS anode often undergo rapid capacity decay and poor rate capability owing to its huge volume fluctuation and structural instability upon the repeated charge/discharge processes. Herein, a novel and versatile method is described for in situ synthesis of ultrathin SnS nanosheets inside and outside hollow mesoporous carbon spheres crosslinked reduced graphene oxide networks. Thus, 3D honeycomb‐like network architecture is formed. Systematic electrochemical studies manifest that this nanocomposite as anode material for lithium‐ion batteries delivers a high charge capacity of 1027 mAh g?1 at 0.2 A g?1 after 100 cycles. Meanwhile, the as‐developed nanocomposite still retains a charge capacity of 524 mAh g?1 at 0.1 A g?1 after 100 cycles for sodium‐ion batteries. In addition, the electrochemical kinetics analysis verifies the basic principles of enhanced rate capacity. The appealing electrochemical performance for both lithium‐ion batteries and sodium‐ion batteries can be mainly related to the porous 3D interconnected architecture, in which the nanoscale SnS nanosheets not only offer decreased ion diffusion pathways and fast Li+/Na+ transport kinetics, but also the 3D interconnected conductive networks constructed from the hollow mesoporous carbon spheres and reduced graphene oxide enhance the conductivity and ensure the structural integrity. 相似文献
15.
Liang Cao Bao Zhang Xing Ou Chunhui Wang Chunli Peng Jiafeng Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(9)
Metal sulfides possess tremendous potentials owing to their high specific capacity for sodium storage. However, the huge volume expansion, accompanied with structural collapse and unsatisfied electric conductivity upon continuous cycling, always lead to inferior rate capability and severe cycling fading. In this work, binary metal sulfide (ZnS/SnS2) nanoboxes confined in N/S dual‐doped carbon shell (ZSS@NSC) are fabricated through a facile co‐precipitation method involving the wrapping of polypyrrole, and subsequent in situ sulfidation process. Such a well‐designed heterogeneity between ZnS and SnS2 provides rapid Na+ insertion and enhanced charge transport by creating an electric field at the heterointerface. More significantly, the formation of polypyrrole‐derived N/S dual‐doped carbon is synergistically coupled with the ZnS/SnS2 to create a unique and robust architecture, further strengthening the interconnect function at the heterointerface, which improves electric/ion transfer and mitigates the volume variation during the long‐term cycling process. Herein, this as‐prepared ZSS@NSC exhibits satisfied specific capacity, excellent rate property, and superior cyclic stability (a reversible capacity of 456.2 mAh g?1 with excellent capacity retention of 97.2% after 700 stable cycles at ultrahigh rate of 5 A g?1). The boosted Na‐storage properties demonstrate that the optimized strategy of structure‐engineering has a broad prospect to promote energy storage applications. 相似文献
16.
Wenhan Guo Wei Xia Kunting Cai Yingxiao Wu Bin Qiu Zibin Liang Chong Qu Ruqiang Zou 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(41)
Heterometallic metal–organic frameworks (MOFs) are constructed from two or more kinds of metal ions, while still remaining their original topologies. Due to distinct reaction kinetics during MOF formation, partial distribution of different metals within a single MOF crystal can lead to sophisticated heterogeneous nanostructures. Here, this study reports an investigation of reaction kinetics for different metal ions in a bimetallic MOF system, the ZIF‐8/67 (M(2‐mIM)2, M = Zn for ZIF‐8, and Co for ZIF‐67, 2‐mIM = 2‐methylimidazole), by in situ optical method. Distinct kinetics of the two metals forming single‐component MOFs are revealed, and when both Co and Zn ions are present in the starting solution, homogeneous distributions of the two metals are only achieved at high Co/Zn ratio, while at low Co/Zn ratio concentration gradient from Co‐rich cores to Zn‐rich shells is observed. Further, by adding the two metals in sequence, more sophisticated structures are achieved. Specifically, when Co2+ is added first, ZIF‐67@ZIF‐8/67 core–shell nanocrystals are achieved with tunable core/shell thickness ratio depending on the time intervals; while when Zn2+ is added first, only agglomerates of irregular shape form due to the weak nucleation ability of Zn2+. 相似文献
17.
Multishelled NixCo3–xO4 Hollow Microspheres Derived from Bimetal–Organic Frameworks as Anode Materials for High‐Performance Lithium‐Ion Batteries 下载免费PDF全文
Lan‐Lan Wu Zhuo Wang Yan Long Jian Li Yu Liu Qi‐Shun Wang Xiao Wang Shu‐Yan Song Xiaogang Liu Hong‐Jie Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(17)
Metal–organic frameworks (MOFs) featuring versatile topological architectures are considered to be efficient self‐sacrificial templates to achieve mesoporous nanostructured materials. A facile and cost‐efficient strategy is developed to scalably fabricate binary metal oxides with complex hollow interior structures and tunable compositions. Bimetal–organic frameworks of Ni‐Co‐BTC solid microspheres with diverse Ni/Co ratios are readily prepared by solvothermal method to induce the Ni x Co3? x O4 multishelled hollow microspheres through a morphology‐inherited annealing treatment. The obtained mixed metal oxides are demonstrated to be composed of nanometer‐sized subunits in the shells and large void spaces left between adjacent shells. When evaluated as anode materials for lithium‐ion batteries, Ni x Co3? x O4‐0.1 multishelled hollow microspheres deliver a high reversible capacity of 1109.8 mAh g?1 after 100 cycles at a current density of 100 mA g?1 with an excellent high‐rate capability. Appropriate capacities of 832 and 673 mAh g?1 could also be retained after 300 cycles at large currents of 1 and 2 A g?1, respectively. These prominent electrochemical properties raise a concept of synthesizing MOFs‐derived mixed metal oxides with multishelled hollow structures for progressive lithium‐ion batteries. 相似文献
18.
Necklace‐Like Structures Composed of Fe3N@C Yolk–Shell Particles as an Advanced Anode for Sodium‐Ion Batteries 下载免费PDF全文
Zhen Li Yongjin Fang Jintao Zhang Xiong Wen Lou 《Advanced materials (Deerfield Beach, Fla.)》2018,30(30)
It is of great importance to develop cost‐effective electrode materials for large‐scale use of Na‐ion batteries. Here, a binder‐free electrode based on necklace‐like structures composed of Fe3N@C yolk–shell particles as an advanced anode for Na‐ion batteries is reported. In this electrode, every Fe3N@C unit has a novel yolk–shell structure, which can accommodate the volumetric changes of Fe3N during the (de)sodiation processes for superior structural integrity. Moreover, all reaction units are threaded along the carbon fibers, guaranteeing excellent kinetics for the electrochemical reactions. As a result, when evaluated as an anode material for Na‐ion batteries, the Fe3N@C nano‐necklace electrode delivers a prolonged cycle life over 300 cycles, and achieves a high C‐rate capacity of 248 mAh g?1 at 2 A g?1. 相似文献
19.
Okra‐Like Fe7S8/C@ZnS/N‐C@C with Core–Double‐Shelled Structures as Robust and High‐Rate Sodium Anode
Dongwei Cao Wenpei Kang Wenhong Wang Kaian Sun Yuyu Wang Ping Ma Daofeng Sun 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(35)
Core–multishelled structures with controlled chemical composition have attracted great interest due to their fascinating electrochemical performance. Herein, a metal–organic framework (MOF)‐on‐MOF self‐templated strategy is used to fabricate okra‐like bimetal sulfide (Fe7S8/C@ZnS/N‐C@C) with core–double‐shelled structure, in which Fe7S8/C is distributed in the cores, and ZnS is embedded in one of the layers. The MOF‐on‐MOF precursor with an MIL‐53 core, a ZIF‐8 shell, and a resorcinol–formaldehyde (RF) layer (MIL‐53@ZIF‐8@RF) is prepared through a layer‐by‐layer assembly method. After calcination with sulfur powder, the resultant structure has a hierarchical carbon matrix, abundant internal interface, and tiered active material distribution. It provides fast sodium‐ion reaction kinetics, a superior pseudocapacitance contribution, good resistance of volume changes, and stepwise sodiation/desodiation reaction mechanism. As an anode material for sodium‐ion batteries, the electrochemical performance of Fe7S8/C@ZnS/N‐C@C is superior to that of Fe7S8/C@ZnS/N‐C, Fe7S8/C, or ZnS/N‐C. It delivers a high and stable capacity of 364.7 mAh g?1 at current density of 5.0 A g?1 with 10 000 cycles, and registers only 0.00135% capacity decay per cycle. This MOF‐on‐MOF self‐templated strategy may provide a method to construct core–multishelled structures with controlled component distributions for the energy conversion and storage. 相似文献
20.
Large‐Scale Fabrication of Core–Shell Structured C/SnO2 Hollow Spheres as Anode Materials with Improved Lithium Storage Performance 下载免费PDF全文
Yong Cheng Qian Li Chunli Wang Lianshan Sun Zheng Yi Limin Wang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(47)
Due to the high theoretical capacity as high as 1494 mAh g?1, SnO2 is considered as a potential anode material for high‐capacity lithium–ion batteries (LIBs). Therefore, the simple but effective method focused on fabrication of SnO2 is imperative. To meet this, a facile and efficient strategy to fabricate core–shell structured C/SnO2 hollow spheres by a solvothermal method is reported. Herein, the solid and hollow structure as well as the carbon content can be controlled. Very importantly, high‐yield C/SnO2 spheres can be produced by this method, which suggest potential business applications in LIBs field. Owing to the dual buffer effect of the carbon layer and hollow structures, the core–shell structured C/SnO2 hollow spheres deliver a high reversible discharge capacity of 1007 mAh g?1 at a current density of 100 mA g?1 after 300 cycles and a superior discharge capacity of 915 mAh g?1 at 500 mA g?1 after 500 cycles. Even at a high current density of 1 and 2 A g?1, the core–shell structured C/SnO2 hollow spheres electrode still exhibits excellent discharge capacity in the long life cycles. Consideration of the superior performance and high yield, the core–shell structured C/SnO2 hollow spheres are of great interest for the next‐generation LIBs. 相似文献