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1.
Carbon‐Sheathed MoS2 Nanothorns Epitaxially Grown on CNTs: Electrochemical Application for Highly Stable and Ultrafast Lithium Storage
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Zijia Zhang Hailei Zhao Yongqiang Teng Xiwang Chang Qing Xia Zhaolin Li Jiejun Fang Zhihong Du Konrad Świerczek 《Liver Transplantation》2018,8(7)
Molybdenum disulfide (MoS2), which possesses a layered structure and exhibits a high theoretical capacity, is currently under intensive research as an anode candidate for next generation of Li‐ion batteries. However, unmodified MoS2 suffers from a poor cycling stability and an inferior rate capability upon charge/discharge processes. Herein, a unique nanocomposite comprising MoS2 nanothorns epitaxially grown on the backbone of carbon nanotubes (CNTs) and coated by a layer of amorphous carbon is synthesized via a simple method. The epitaxial growth of MoS2 on CNTs results in a strong chemical coupling between active nanothorns and carbon substrate via C? S bond, providing a high stability as well as a high‐efficiency electron‐conduction/ion‐transportation system on cycling. The outer carbon layer can well‐accommodate the structural strain in the electrode upon lithium‐ion insertion/extraction. When employed as an anode for lithium storage, the prepared material exhibits remarkable electrochemical properties with a high specific capacity of 982 mA h g?1 at 0.1 A g?1, as well as excellent long‐cycling stability (905 mA h g?1 at 1 A g?1 after 500 cycles) and superior rate capability, confirming its potential application in high‐performance Li‐ion batteries. 相似文献
2.
Vertically Aligned MoS2 Nanosheets Patterned on Electrochemically Exfoliated Graphene for High‐Performance Lithium and Sodium Storage
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Gang Wang Jian Zhang Sheng Yang Faxing Wang Xiaodong Zhuang Klaus Müllen Xinliang Feng 《Liver Transplantation》2018,8(8)
Molybdenum disulfide (MoS2) has been recognized as a promising anode material for high‐energy Li‐ion (LIBs) and Na‐ion batteries (SIBs) due to its apparently high capacity and intriguing 2D‐layered structure. The low conductivity, unsatisfied mechanical stability, and limited active material utilization are three key challenges associated with MoS2 electrodes especially at high current rates and mass active material loading. Here, vertical MoS2 nanosheets are controllably patterned onto electrochemically exfoliated graphene (EG). Within the achieved hierarchical architecture, the intimate contact between EG and MoS2 nanosheets, interconnected network, and effective exposure of active materials by vertical channels simultaneously overcomes the above three problems, enabling high mechanical integrity and fast charge transport kinetics. Serving as anode material for LIBs, EG‐MoS2 with 95 wt% MoS2 content delivered an ultrahigh‐specific capacity of 1250 mA h g?1 after 150 stable cycles at 1 A g?1, which is among the highest values in all reported MoS2 electrodes, and excellent rate performance (970 mA h g?1 at 5 A g?1). Moreover, impressive cycling stability (509 mA h g?1 at 1 A g?1 after 250 cycles) and rate capability (423 mA h g?1 at 2 A g?1) were also achieved for SIBs. The area capacities reached 1.27 and 0.49 mA h cm?2 at ≈1 mA cm?2 for LIBs and SIBs, respectively. This work may inspire the development of new 2D hierarchical structures for high efficiency energy storage and conversion. 相似文献
3.
Inspired by the great success of graphite in lithium‐ion batteries, anode materials that undergo an intercalation mechanism are considered to provide stable and reversible electrochemical sodium‐ion storage for sodium‐ion battery (SIB) applications. Though MoS2 is a promising 2D material for SIBs, it suffers from deformation of its layered structure during repeated intercalation of Na+, resulting in undesirable electrochemical behaviors. In this study, vertically oriented MoS2 on nitrogenous reduced graphene oxide sheets (VO‐MoS2/N‐RGO) is presented with designed spatial geometries, including sheet density and height, which can deliver a remarkably high reversible capacity of 255 mA h g?1 at a current density of 0.2 A g?1 and 245 mA h g?1 at a current density of 1 A g?1, with a total fluctuation of 5.35% over 1300 cycles. These results are superior to those obtained with well‐developed hard carbon structures. Furthermore, a SIB full cell composed of the optimized VO‐MoS2/N‐RGO anode and a Na2V3(PO4)3 cathode reaches a specific capacity of 262 mA h g?1 (based on the anode mass) during 50 cycles, with an operated voltage range of 2.4 V, demonstrating the potentially rewarding SIB performance, which is useful for further battery development. 相似文献
4.
Tianhui Xu Peng Gao Peirong Li Kai Xia Na Han Jun Deng Yanguang Li Jun Lu 《Liver Transplantation》2020,10(8)
Li metal anodes are going through a great revival but they still encounter grand challenges. One often neglected issue is that most reported Li metal anodes are only cyclable under relatively low current density (<5 mA cm?2) and small areal capacity (<5 mAh cm?2), which essentially limits their high‐power applications and results in ineffective Li utilization (<1%). Herein, it is reported that surface alloyed Li metal anodes can enable reversible cycling with ultrafast rate and ultralarge areal capacity. Low‐cost Si wafers are used and are chemically etched down to 20–30 µm membranes. Simply laminating a Si membrane onto Li foil results in the formation of LixSi alloy film fused onto Li metal with mechanical robustness and high Li‐ion conductivity. Symmetric cell measurements show that the surface alloyed Li anode has excellent cycling stability, even under high current density up to 25 mA cm?2 and unprecedented areal capacity up to 100 mAh cm?2. Furthermore, the surface alloyed Li anode is paired with amorphous MoS3 cathode and achieves remarkable full‐cell performance. 相似文献
5.
Xinxin Cao Anqiang Pan Sainan Liu Jiang Zhou Site Li Guozhong Cao Jun Liu Shuquan Liang 《Liver Transplantation》2017,7(20)
Sodium (Na) super ion conductor structured Na3V2(PO4)3 (NVP) is extensively explored as cathode material for sodium‐ion batteries (SIBs) due to its large interstitial channels for Na+ migration. The synthesis of 3D graphene‐like structure coated on NVP nanoflakes arrays via a one‐pot, solid‐state reaction in molten hydrocarbon is reported. The NVP nanoflakes are uniformly coated by the in situ generated 3D graphene‐like layers with the thickness of 3 nm. As a cathode material, graphene covered NVP nanoflakes exhibit excellent electrochemical performances, including close to theoretical reversible capacity (115.2 mA h g?1 at 1 C), superior rate capability (75.9 mA h g?1 at 200 C), and excellent cyclic stability (62.5% of capacity retention over 30000 cycles at 50 C). Furthermore, the 3D graphene‐like cages after removing NVP also serve as a good anode material and deliver a specific capacity of 242.5 mA h g?1 at 0.1 A g?1. The full SIB using these two cathode and anode materials delivers a high specific capacity (109.2 mA h g?1 at 0.1 A g?1) and good cycling stability (77.1% capacity retention over 200 cycles at 0.1 A g?1). 相似文献
6.
MoS2/Graphene Nanosheets from Commercial Bulky MoS2 and Graphite as Anode Materials for High Rate Sodium‐Ion Batteries
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Dan Sun Delai Ye Ping Liu Yougen Tang Jun Guo Lianzhou Wang Haiyan Wang 《Liver Transplantation》2018,8(10)
Tuning heterointerfaces between hybrid phases is a very promising strategy for designing advanced energy storage materials. Herein, a low‐cost, high‐yield, and scalable two‐step approach is reported to prepare a new type of hybrid material containing MoS2/graphene nanosheets prepared from ball‐milling and exfoliation of commercial bulky MoS2 and graphite. When tested as an anode material for a sodium‐ion battery, the as‐prepared MoS2/graphene nanosheets exhibit remarkably high rate capability (284 mA h g?1 at 20 A g?1 (≈30C) and 201 mA h g?1 at 50 A g?1 (≈75C)) and excellent cycling stability (capacity retention of 95% after 250 cycles at 0.3 A g?1). Detailed experimental measurements and density functional theory calculation reveal that the functional groups in 2D MoS2/graphene heterostructures can be well tuned. The impressive rate capacity of the as‐prepared MoS2/graphene hybrids should be attributed to the heterostructures with a low degree of defects and residual oxygen containing groups in graphene, which subsequently improve the electronic conductivity of graphene and decrease the Na+ diffusion barrier at the MoS2/graphene interfaces in comparison with the acid treated one. 相似文献
7.
Yijun Chen Yunsong Wang Zhipeng Wang Mingchu Zou Hui Zhang Wenqi Zhao Muhammad Yousaf Liusi Yang Anyuan Cao Ray P. S. Han 《Liver Transplantation》2018,8(19)
Achieving a high areal capacity is essential for the transfer of outstanding laboratory electrode results to commercial applications and also to ensure there exists a capacity matched cathode and anode for a properly tuned battery. Despite intensive efforts, most electrode materials exhibit areal capacities lower than that of the graphite anodes (4 mA h cm?2). An effective and low‐cost approach is reported to attain a high areal capacity via an intense densification by compacting a porous carbon nanotube sponge grafted with Co3O4 nanoparticles. The hybrid sponge can be compacted to a large degree (up to a tenfold densification) while still keeping its structural integrity and the 3D porous network. This method allows achieving a mass loading of up ?to 14.3 mg cm?2 and an areal capacity of 12 mA h cm?2 (at a current density of 200 mA g?1) together with a gravimetric capacity of >800 mA h g?1. This densification by compaction approach offers an effective and low‐cost strategy to develop high mass loading and areal capacity electrodes for practical energy storage systems. 相似文献
8.
Ion Transport Nanotube Assembled with Vertically Aligned Metallic MoS2 for High Rate Lithium‐Ion Batteries
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Yucong Jiao Alolika Mukhopadhyay Yi Ma Lei Yang Ahmed M. Hafez Hongli Zhu 《Liver Transplantation》2018,8(15)
Metallic phase molybdenum disulfide (MoS2) is well known for orders of magnitude higher conductivity than 2H semiconducting phase MoS2. Herein, for the first time, the authors design and fabricate a novel porous nanotube assembled with vertically aligned metallic MoS2 nanosheets by using the scalable solvothermal method. This metallic nanotube has the following advantages: (i) intrinsic high electrical conductivity that promotes the rate performance of battery and eliminates the using of conductive additive; (ii) hierarchical, hollow, porous, and aligned structure that assists the electrolyte transportation and diffusion; (iii) tubular structure that avoids restacking of 2D nanosheets, and therefore maintains the electrochemistry cycling stability; and (iv) a shortened ion diffusion path, that improves the rate performance. This 1D metallic MoS2 nanotube is demonstrated to be a promising anode material for lithium‐ion batteries. The unique structure delivers an excellent reversible capacity of 1100 mA h g?1 under a current density of 5 A g?1 after 350 cycles, and an outstanding rate performance of 589 mA h g?1 at a current density of 20 A g?1. Furthermore, attributed to the material's metallic properties, the electrode comprising 100% pure material without any additive provides an ideal system for the fundamental electrochemical study of metallic MoS2. This study first reveals the characteristic anodic peak at 1.5 V in cyclic voltammetry of metallic MoS2. This research sheds light on the fabrication of metallic 1D, 2D, or even 3D structures with 2D nanosheets as building blocks for various applications. 相似文献
9.
Hierarchical Zn–Co–S Nanowires as Advanced Electrodes for All Solid State Asymmetric Supercapacitors
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A facile two‐step strategy is developed to design the large‐scale synthesis of hierarchical, unique porous architecture of ternary metal hydroxide nanowires grown on porous 3D Ni foam and subsequent effective sulfurization. The hierarchical Zn–Co–S nanowires (NWs) arrays are directly employed as an electrode for supercapacitors application. The as‐synthesized Zn–Co–S NWs deliver an ultrahigh areal capacity of 0.9 mA h cm?2 (specific capacity of 366.7 mA h g?1) at a current density of 3 mA cm?2, with an exceptional rate capability (≈227.6 mA h g?1 at a very high current density of 40 mA cm?2) and outstanding cycling stability (≈93.2% of capacity retention after 10 000 cycles). Most significantly, the assembled Zn–Co–S NWs//Fe2O3@reduced graphene oxide asymmetric supercapacitors with a wide operating potential window of ≈1.6 V yield an ultrahigh volumetric capacity of ≈1.98 mA h cm?3 at a current density of 3 mA cm?2, excellent energy density of ≈81.6 W h kg?1 at a power density of ≈559.2 W kg?1, and exceptional cycling performance (≈92.1% of capacity retention after 10 000 cycles). This general strategy provides an alternative to design the other ternary metal sulfides, making it facile, free‐standing, binder‐free, and cost‐effective ternary metal sulfide‐based electrodes for large‐scale applications in modern electronics. 相似文献
10.
Amorphous Tin‐Based Composite Oxide: A High‐Rate and Ultralong‐Life Sodium‐Ion‐Storage Material
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Xu Yang Rong‐Yu Zhang Jing Zhao Zhi‐Xuan Wei Dong‐Xue Wang Xiao‐Fei Bie Yu Gao Jia Wang Fei Du Gang Chen 《Liver Transplantation》2018,8(8)
Energy‐storage technology is moving beyond lithium batteries to sodium as a result of its high abundance and low cost. However, this sensible transition requires the discovery of high‐rate and long‐lifespan anode materials, which remains a significant challenge. Here, the facile synthesis of an amorphous Sn2P2O7/reduced graphene oxide nanocomposite and its sodium storage performance between 0.01 and 3.0 V are reported for the first time. This hybrid electrode delivers a high specific capacity of 480 mA h g?1 at a current density of 50 mA g?1 and superior rate performance of 250 and 165 mA h g?1 at 2 and 10 A g?1, respectively. Strikingly, this anode can sustain 15 000 cycles while retaining over 70% of the initial capacity. Quantitative kinetic analysis reveals that the sodium storage is governed by pseudocapacitance, particularly at high current rates. A full cell with sodium super ionic conductor (NASICON)‐structured Na3V2(PO4)2F3 and Na3V2(PO4)3 as cathodes exhibits a high energy density of over 140 W h kg?1 and a power density of nearly 9000 W kg?1 as well as stability over 1000 cycles. This exceptional performance suggests that the present system is a promising power source for promoting the substantial use of low‐cost energy storage systems. 相似文献
11.
Jing Zhang Kai Zhang Junghoon Yang Gi‐Hyeok Lee Jeongyim Shin Vincent Wing‐hei Lau Yong‐Mook Kang 《Liver Transplantation》2018,8(20)
This study proposes a conformal surface coating of conducting polymer for protecting 1D nanostructured electrode material, thereby enabling a free‐standing electrode without binder for sodium ion batteries. Here, polypyrrole (PPy), which is one of the representative conducting polymers, encapsulated cobalt phosphide (CoP) nanowires (NWs) grown on carbon paper (CP), finally realizes 1D core–shell CoP@PPy NWs/CP. The CoP core is connected to the PPy shell via strong chemical bonding, which can maintain a Co–PPy framework during charge/discharge. It also possesses bifunctional features that enhances the charge transfer and buffers the volume expansion. Consequently, 1D core–shell CoP@PPy NWs/CP demonstrates superb electrochemical performance, delivering a high areal capacity of 0.521 mA h cm?2 at 0.15 mA cm?2 after 100 cycles, and 0.443 mA h cm?2 at 1.5 mA cm?2 even after 1000 cycles. Even at a high current density of 3 mA cm?2, a significant areal discharge capacity reaching 0.285 mA h cm?2 is still maintained. The outstanding performance of the CoP@PPy NWs/CP free‐standing anode provides not only a novel insight into the modulated volume expansion of anode materials but also one of the most effective strategies for binder‐free and free‐standing electrodes with decent mechanical endurance for future secondary batteries. 相似文献
12.
Xuejie Gao Xiaofei Yang Keegan Adair Xiaona Li Jianwen Liang Qian Sun Yang Zhao Ruing Li Tsun‐Kong Sham Xueliang Sun 《Liver Transplantation》2020,10(7)
Although metallic lithium is regarded as the “Holy Grail” for next‐generation rechargeable batteries due to its high theoretical capacity and low overpotential, the uncontrollable Li dendrite growth, especially under high current densities and deep plating/striping, has inhibited its practical application. Herein, a 3D‐printed, vertically aligned Li anode (3DP‐VALi) is shown to efficiently guide Li deposition via a “nucleation within microchannel walls” process, enabling a high‐performance, dendrite‐free Li anode. Moreover, the microchannels within the microwalls are beneficial for promoting fast Li+ diffusion, supplying large space for the accommodation of Li during the plating/stripping process. The high‐surface‐area 3D anode design enables high operating current densities and high areal capacities. As a result, the Li–Li symmetric cells using 3DP‐VALi demonstrate excellent electrochemical performances as high as 10 mA cm?2/10 mAh cm?2 for 1500 h and 5 mA cm?2/20 mAh cm?2 for 400 h, respectively. Additionally, the Li–S and Li–LiFePO4 cells using 3DP‐VALi anodes present excellent cycling stability up to 250 and 800 cycles at a rate of 1 C, respectively. It is believed that these new findings could open a new window for dendrite‐free metal anode design and pave the way toward energy storage devices with high energy/power density. 相似文献
13.
Harihara Padhy Yingqian Chen Johann Lüder Satyanarayana Reddy Gajella Sergei Manzhos Palani Balaya 《Liver Transplantation》2018,8(7)
A combined experimental and computational study of disodium pyridine‐2,5‐dicarboxylate (Na2PDC) is presented exploring the possibility of using it as a potential anode for organic sodium‐ion batteries. This electrode material can reversibly insert/release two Na cations per formula unit, resulting in high reversible capacity of 270 mA h g?1 (236 mA h g?1 after accounting for the contribution from Super P carbon) with excellent cyclability 225 mA h g?1, with retention of 83% capacity after 100 cycles, and good rate performance with reversible capacity of 138 mA h g?1 at a 5 C rate. The performance of disodium pyridine dicarboxylate is therefore found to be superior to that of the related and well investigated disodium terephthalate. The material shows two voltage plateaus at about 0.6 V up to Na2+1PDC and then 0.4 V up to full sodiation, Na2+2PDC. The first plateau is attributed to the coordination of inserted Na to nitrogen atoms with bond formation, i.e., a different mechanism from the terephthalate analog. The subsequent plateau is due to coordination to the carboxylic groups. 相似文献
14.
Biwei Xiao Fernando A. Soto Meng Gu Kee Sung Han Junhua Song Hui Wang Mark H. Engelhard Vijayakumar Murugesan Karl T. Mueller David Reed Vincent L. Sprenkle Perla B. Balbuena Xiaolin Li 《Liver Transplantation》2018,8(24)
Hard carbon (HC) is the state‐of‐the‐art anode material for sodium‐ion batteries (SIBs). However, its performance has been plagued by the limited initial Coulombic efficiency (ICE) and mediocre rate performance. Here, experimental and theoretical studies are combined to demonstrate the application of lithium‐pretreated HC (LPHC) as high‐performance anode materials for SIBs by manipulating the solid electrolyte interphase in tetraglyme (TEGDME)‐based electrolyte. The LPHC in TEGDME can 1) deliver > 92% ICE and ≈220 mAh g?1 specific capacity, twice of the capacity (≈100 mAh g?1) in carbonate electrolyte; 2) achieve > 85% capacity retention over 1000 cycles at 1000 mA g?1 current density (4 C rate, 1 C = 250 mA g?1) with a specific capacity of ≈150 mAh g?1, ≈15 times of the capacity (10 mAh g?1) in carbonate. The full cell of Na3V2(PO4)3‐LPHC in TEGDME demonstrated close to theoretical specific capacity of ≈98 mAh g?1 based on Na3V2(PO4)3 cathode, ≈2.5 times of the value (≈40 mAh g?1) with nontreated HC. This work provides new perception on the anode development for SIBs. 相似文献
15.
Exploring new structure prototypes and phases by material design, especially anode materials, is essential to develop high‐performance Na‐ion batteries. This study proposes a new anode, Na2Cu2.09O0.50S2, with a 1D crystal structure and outstanding Na storage performance. In view of the crystal structure of Na2Cu2.09O0.50S2, [Cu4S4] chains act as electrically conducting units enabling conductivity as high as 0.5 S cm?1. The residual Na4[CuO] chains act as ionically conducting units forming rich channels for the fast conduction of Na ions as well as maintaining the structural stability even after Na ion extraction. Additional ball milling on the as‐prepared Na2Cu2.09O0.50S2 significantly decreases its grain size, achieving a capacity of 588 mA h g?1 with a high initial Coulombic efficiency of 93% at 0.2 A g?1. Moreover, the Na2Cu2.09O0.50S2 anode demonstrates outstanding rate capability (408 mA h g?1 at 2 A g?1) and extending cyclic performance (82% of capacity retention after 400 cycles). The general structural design idea based on functional units may offer a new avenue to new electrode materials. 相似文献
16.
Sahin Cangaz Felix Hippauf Florian Steffen Reuter Susanne Doerfler Thomas Abendroth Holger Althues Stefan Kaskel 《Liver Transplantation》2020,10(34)
All‐solid‐state batteries (ASSBs) with silicon anodes are promising candidates to overcome energy limitations of conventional lithium‐ion batteries. However, silicon undergoes severe volume changes during cycling leading to rapid degradation. In this study, a columnar silicon anode (col‐Si) fabricated by a scalable physical vapor deposition process (PVD) is integrated in all‐solid‐state batteries based on argyrodite‐type electrolyte (Li6PS5Cl, 3 mS cm?1) and Ni‐rich layered oxide cathodes (LiNi0.9Co0.05Mn0.05O2, NCM) with a high specific capacity (210 mAh g?1). The column structure exhibits a 1D breathing mechanism similar to lithium, which preserves the interface toward the electrolyte. Stable cycling is demonstrated for more than 100 cycles with a high coulombic efficiency (CE) of 99.7–99.9% in full cells with industrially relevant areal loadings of 3.5 mAh cm?2, which is the highest value reported so far for ASSB full cells with silicon anodes. Impedance spectroscopy revealed that anode resistance is drastically reduced after first lithiation, which allows high charging currents of 0.9 mA cm?2 at room temperature without the occurrence of dendrites and short circuits. Finally, in‐operando monitoring of pouch cells gave valuable insights into the breathing behavior of the solid‐state cell. 相似文献
17.
Fabrication of Hierarchical Potassium Titanium Phosphate Spheroids: A Host Material for Sodium‐Ion and Potassium‐Ion Storage
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Zhixuan Wei Dongxue Wang Malin Li Yu Gao Chunzhong Wang Gang Chen Fei Du 《Liver Transplantation》2018,8(27)
Identifying suitable electrode materials for sodium‐ion and potassium‐ion storage holds the key to the development of earth‐abundant energy‐storage technologies. This study reports an anode material based on self‐assembled hierarchical spheroid‐like KTi2(PO4)3@C nanocomposites synthesized via an electrospray method. Such an architecture synergistically combines the advantages of the conductive carbon network and allows sufficient space for the infiltration of the electrolyte from the porous structure, leading to an impressive electrochemical performance, as reflected by the high reversible capacity (283.7 mA h g?1 for Na‐ion batteries; 292.7 mA h g?1 for K‐ion batteries) and superior rate capability (136.1 mA h g?1 at 10 A g?1 for Na‐ion batteries; 133.1 mA h g?1 at 1 A g?1 for K‐ion batteries) of the resulting material. Moreover, the different ion diffusion behaviors in the two systems are revealed to account for the difference in rate performance. These findings suggest that KTi2(PO4)3@C is a promising candidate as an anode material for sodium‐ion and potassium‐ion batteries. In particular, the present synthetic approach could be extended to other functional electrode materials for energy‐storage materials. 相似文献
18.
Sodium‐based dual ion full batteries (NDIBs) are reported with soft carbon as anode and graphite as cathode for the first time. The NDIBs operate at high discharge voltage plateau of 3.58 V, with superior discharge capacity of 103 mA h g?1, excellent rate performance, and long‐term cycling stability over 800 cycles with capacity retention of 81.8%. The mechanism of Na+ and PF6? insertion/desertion during the charging/discharging processes is proposed and discussed in detail, with the support of various spectroscopies. 相似文献
19.
Highly Reversible Na Storage in Na3V2(PO4)3 by Optimizing Nanostructure and Rational Surface Engineering
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Sodium‐ion batteries (NIBs) have attracted more and more attention as economic alternatives for lithium‐ion batteries (LIBs). Sodium super ionic conductor (NASICON) structure materials, known for high conductivity and chemical diffusion coefficient of Na+ (≈10?14 cm2 s?1), are promising electrode materials for NIBs. However, NASICON structure materials often suffer from low electrical conductivity (<10?4 S cm?1), which hinders their electrochemical performance. Here high performance sodium storage performance in Na3V2(PO4)3 (NVP) is realized by optimizing nanostructure and rational surface engineering. A N, B codoped carbon coated three‐dimensional (3D) flower‐like Na3V2(PO4)3 composite (NVP@C‐BN) is designed to enable fast ions/electrons transport, high‐surface controlled energy storage, long‐term structural integrity, and high‐rate cycling. The conductive 3D interconnected porous structure of NVP@C‐BN greatly releases mechanical stress from Na+ extraction/insertion. In addition, extrinsic defects and active sites introduced by the codoping heteroatoms (N, B) both enhance Na+ and e? diffusion. The NVP@C‐BN displays excellent electrochemical performance as the cathode, delivering reversible capacity of 70% theoretical capacity at 100 C after 2000 cycles. When used as anode, the NVP@C‐BN also shows super long cycle life (38 mA h g?1 at 20 C after 5000 cycles). The design provides a novel approach to open up possibilities for designing high‐power NIBs. 相似文献
20.
Owing to its high theoretical specific capacity (1166 mA h g?1) and particularly its advantage to be paired with a lithium‐metal‐free anode, lithium sulfide (Li2S) is regarded as a much safer cathode for next‐generation advanced lithium–sulfur (Li–S) batteries. However, the low conductivity of Li2S and particularly the severe “polysulfide shuttle” of lithium polysulfide (LiPS) dramatically hinder their practical application in Li–S batteries. To address such issues, herein a bifuctional 3D metal sulfide‐decorated carbon sponge (3DTSC), which is constructed by 1D carbon nanowires cross‐linked with 2D graphene nanosheets with high conductivity and polar 0D metal sulfide nanodots with efficient electrocatalytic activity and strong chemical adsorption capability for LiPSs, is presented. Benefiting from the well‐designed multiscale, multidimensional 3D porous nanoarchitecture with high conductivity, and efficient electrocatalytic and absorption ability, the 3DTSC significantly mitigates LiPS shuttle, improves the utilization of Li2S, and facilitates the transport of electrons and ions. As a result, even with a high Li2S loading of 8 mg cm?2, the freestanding 3DTSC‐Li2S cathode without a polymer binder and metallic current collector delivers outstanding electrochemical performance with a high areal capacity of 8.44 mA h cm?2. 相似文献