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1.
Yin Hu Wei Chen Tianyu Lei Yu Jiao Jianwen Huang Anjun Hu Chuanhui Gong Chaoyi Yan Xianfu Wang Jie Xiong 《Liver Transplantation》2020,10(17)
Lithium–sulfur (Li–S) batteries, due to the high theoretical energy density, are regarded as one of the most promising candidates for breaking the limitations of energy‐storage system based on Li‐ion batteries. Tremendous efforts have been made to meet the challenge of high‐performance Li–S batteries, in which a sulfur loading of above 5 mg cm?2 delivers an areal capacity higher than 5 mAh cm?2 without compromising specific capacity and cycling stability for practical applications. However, serious problems have been exposed during the scaling up of the sulfur loading. In this review, based on mechanistic insights into structural configuration, catalytic conversion, and interfacial engineering, the problems and corresponding strategies in the development of high‐loading Li–S batteries are highlighted and discussed, aiming at bridging the gap between fundamental research and practical cell‐level designs. Stemming from the current achievements, future directions targeting the high‐energy‐density Li–S batteries for commercialization are proposed. 相似文献
2.
In Situ Assembly of 2D Conductive Vanadium Disulfide with Graphene as a High‐Sulfur‐Loading Host for Lithium–Sulfur Batteries
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Xingyu Zhu Wen Zhao Yingze Song Qiucheng Li Feng Ding Jingyu Sun Li Zhang Zhongfan Liu 《Liver Transplantation》2018,8(20)
Lithium–sulfur (Li–S) batteries are deemed to be one of the most promising energy storage technologies because of their high energy density, low cost, and environmental benignancy. However, existing drawbacks including the shuttling of intermediate polysulfides, the insulating nature of sulfur, and the considerable volume change of sulfur cathode would otherwise result in the capacity fading and unstable cycling. To overcome these challenges, herein an in situ assembly route is presented to fabricate VS2/reduced graphene oxide nanosheets (G–VS2) as a sulfur host. Benefiting from the 2D conductive and polar VS2 interlayered within a graphene framework, the obtained G–VS2 hybrids can effectively suppress the polysulfide shuttling, facilitate the charge transport, and cushion the volume expansion throughout the synergistic effect of structural confinement and chemical anchoring. With these advantageous features, the obtained sulfur cathode (G–VS2/S) can deliver an outstanding rate capability (≈950 and 800 mAh g?1 at 1 and 2 C, respectively) and an impressive cycling stability at high rates (retaining ≈532 mAh g?1 after 300 cycles at 5 C). More significantly, it enables superior cycling performance of high‐sulfur‐loading cathodes (achieving an areal capacity of 5.1 mAh cm?2 at 0.2 C with a sulfur loading of 5 mg cm?2) even at high current densities. 相似文献
3.
Elastic Sandwich‐Type rGO–VS2/S Composites with High Tap Density: Structural and Chemical Cooperativity Enabling Lithium–Sulfur Batteries with High Energy Density
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Driven by increasing demand for high‐energy‐density batteries for consumer electronics and electric vehicles, substantial progress is achieved in the development of long‐life lithium–sulfur (Li–S) batteries. Less attention is given to Li–S batteries with high volume energy density, which is crucial for applications in compact space. Here, a series of elastic sandwich‐structured cathode materials consisting of alternating VS2‐attached reduced graphene oxide (rGO) sheets and active sulfur layers are reported. Due to the high polarity and conductivity of VS2, a small amount of VS2 can suppress the shuttle effect of polysulfides and improve the redox kinetics of sulfur species in the whole sulfur layer. Sandwich‐structured rGO–VS2/S composites exhibit significantly improved electrochemical performance, with high discharge capacities, low polarization, and excellent cycling stability compared with their bare rGO/S counterparts. Impressively, the tap density of rGO–VS2/S with 89 wt% sulfur loading is 1.84 g cm?3, which is almost three times higher than that of rGO/S with the same sulfur content (0.63 g cm?3), and the volumetric specific capacity of the whole cell is as high as 1182.1 mA h cm?3, comparable with the state‐of‐the‐art reported for energy storage devices, demonstrating the potential for application of these composites in long‐life and high‐energy‐density Li–S batteries. 相似文献
4.
Handing Liu Ziliang Chen Lin Zhou Ke Pei Pingdi Xu Linshen Xin Qingwen Zeng Jie Zhang Renbing Wu Fang Fang Renchao Che Dalin Sun 《Liver Transplantation》2019,9(37)
Inhibiting the shuttle effect of lithium polysulfides and accelerating their conversion kinetics are crucial for the development of high‐performance lithium–sulfur (Li–S) batteries. Herein, a modified template method is proposed to synthesize the robust yolk–shell sulfur host that is constructed by enveloping dispersive Fe2O3 nanoparticles within Mn3O4 nanosheet‐grafted hollow N‐doped porous carbon capsules (Fe2O3@N‐PC/Mn3O4‐S). When applied as a cathode for Li–S batteries, the as‐prepared Fe2O3@N‐PC/Mn3O4‐S can deliver capacities as high as 1122 mAh g?1 after 200 cycles at 0.5 C and 639 mAh g?1 after 1500 cycles at 10 C, respectively. Remarkably, even as the areal sulfur loading is increased to 5.1 mg cm?2, the cathode can still maintain a high areal specific capacity of 5.08 mAh cm?2 with a fading rate of only 0.076% per cycle over 100 cycles at 0.1 C. By a further combination analysis of electron holography and electron energy loss spectroscopy, the outstanding performance is revealed to be mainly traced to the oxygen‐vacancy‐induced interfacial charge field, which immobilizes and catalyzes the conversion of lithium polysulfides, assuring low polarization, fleet redox reaction kinetics, and sufficient utilization of sulfur. These new findings may shed light on the dependence of electrochemical performance on the heterostructure of sulfur hosts. 相似文献
5.
Chemical Immobilization and Conversion of Active Polysulfides Directly by Copper Current Collector: A New Approach to Enabling Stable Room‐Temperature Li‐S and Na‐S Batteries
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Peirong Li Lu Ma Tianpin Wu Hualin Ye Junhua Zhou Feipeng Zhao Na Han Yeyun Wang Yunling Wu Yanguang Li Jun Lu 《Liver Transplantation》2018,8(22)
Room‐temperature Li/Na‐S batteries are promising energy storage solutions, but unfortunately suffer from serious cycling problems rooted in their polysulfide intermediates. The conventional strategy to tackle this issue is to design host materials for trapping polysulfides via weak physical confinement and interfacial chemical interactions. Even though beneficial, their capability for the polysulfide immobilization is still limited. Herein, the unique sulfiphilic nature of metallic Cu is revisited. Upon the exposure to polysulfide in aqueous or aprotic solution, the surface sulfidization rapidly takes place, resulting in the formation of Cu2S nanoflake arrays with tunable texture. When the sulfidized Cu current collector is directly used as the sulfur‐equivalent cathode, it enables high‐performance Li/Na‐S batteries at room temperature with reasonable high sulfur loading. Specific capacities up to ≈1200 mAh g?1 for Li‐S and ≈400 mAh g?1 for Na‐S are measured when normalized to the amount of equivalent sulfur, and can be readily sustained for >1000 cycles. 相似文献
6.
Lithium‐sulfur (Li‐S) batteries are considered to be one of the promising next‐generation energy storage systems. Considerable progress has been achieved in sulfur composite cathodes, but high cycling stability and discharging capacity at the expense of volumetric capacity have offset their advantages. Herein, a functional separator is presented by coating cobalt‐embedded nitrogen‐doped porous carbon nanosheets and graphene on one surface of a commercial polypropylene separator. The coating layer not only suppresses the polysulfide shuttle effect through chemical affinity, but also functions as an electrocatalyst to propel catalytic conversion of intercepted polysulfides. The slurry‐bladed carbon nanotubes/sulfur cathode with 90 wt% sulfur deliver high reversible capacity of 1103 mA h g?1 and volumetric capacity of 1062 mA h cm?3 at 0.2 C, and the freestanding carbon nanofibers/sulfur cathode provides a high discharging capacity of 1190 mA h g?1 and volumetric capacity of 1136 mA h cm?3 at high sulfur content of 78 wt% and sulfur loading of 10.5 mg cm?2. The electrochemical performance is comparable with or even superior to those in the state‐of‐the‐art carbon‐based sulfur cathodes. The separator reported in this work holds great promise for the development of high‐energy‐density Li‐S batteries. 相似文献
7.
Tianshuai Wang Pengbo Zhai Dominik Legut Lei Wang Xiaopeng Liu Bixuan Li Chenxi Dong Yanchen Fan Yongji Gong Qianfan Zhang 《Liver Transplantation》2019,9(24)
Lithium metal is the most promising anode material for next‐generation batteries, owing to its high theoretical specific capacity and low electrochemical potential. However, the practical application of lithium metal batteries (LMBs) has been plagued by the issues of uncontrollable lithium deposition. The multifunctional nanostructured anode can modulate the initial nucleation process of lithium before the extension of dendrites. By combing the theoretical design and experimental validation, a novel nucleation strategy is developed by introducing sulfur (S) to graphene. Through first‐principles simulations, it is found that S atom doping can improve the Li adsorption ability on a large area around the S doping positions. Consequently, S‐doped graphene with five lithiophilic sites rather than a single atomic site can serve as the pristine nucleation area, reducing the uneven Li deposition and improving the electrochemical performance. Modifying Li metal anodes by S‐doped graphene enables an ultralow overpotential of 5.5 mV, a high average Coulombic efficiency of 99% over more than 180 cycles at a current density of 0.5 mA cm?2 for 1.0 mAh cm?2, and a high areal capacity of 3 mAh cm?2. This work sheds new light on the rational design of nucleation area materials for dendrite‐free LMB. 相似文献
8.
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
9.
Aqueous zinc batteries are considered as promising alternatives to lithium ion batteries owing to their low cost and high safety. However, the developments of state‐of‐the‐art zinc‐ion batteries (ZIB) and zinc–air batteries (ZAB) are limited by the unsatisfied capacities and poor cycling stabilities, respectively. It is of significance in utilizing the long‐cycle life of ZIB and high capacity of ZAB to exploit advanced energy storage systems. Herein, a bulk composite of graphene oxide and vanadium oxide (V5O12·6H2O) as cathode material for aqueous Zn batteries in a mild electrolyte is employed. The battery performance is demonstrated to arise from a combination of the reversible cations insertion/extraction in vanadium oxide and especially the electrochemical redox reactions on the surface functional groups of graphene oxide (named as pseudo‐Zn–air mechanism). Along with adjusting the hydroxyl content on the surface of graphene oxide, the specific capacity is significantly increased from 342 mAh g?1 to a maximum of 496 mAh g?1 at 100 mA g?1. The surface‐controlled kinetics occurring in the bulk composite ensure a high areal capacity of 10.6 mAh cm?2 at a mass loading of 26.5 mg cm?2, and a capacity retention of 84.7% over 10 000 cycles at a high current density of 10 A g?1. 相似文献
10.
Yin Hu Wei Chen Tianyu Lei Bin Zhou Yu Jiao Yichao Yan Xinchuan Du Jianwen Huang Chunyang Wu Xuepeng Wang Yang Wang Bo Chen Jun Xu Chao Wang Jie Xiong 《Liver Transplantation》2019,9(7)
Significant progress has achieved for developing lithium–sulfur (Li–S) batteries with high specific capacities and excellent cyclic stability. However, some critical issues emerge when attempts are made to raise the areal sulfur loading and increase the operation current density to meet the standards for various industrial applications. In this work, polyethylenimine‐functionalized carbon dots (PEI‐CDots) are designed and prepared for enhancing performance of the Li–S batteries with high sulfur loadings and operation under high current density situations. Strong chemical binding effects towards polysulfides and fast ion transport property are achieved in the PEI‐CDots‐modified cathodes. At a high current density of 8 mA cm?2, the PEI‐CDots‐modified Li–S battery delivers a reversible areal capacity of 3.3 mAh cm?2 with only 0.07% capacity decay per cycle over 400 cycles at 6.6 mg sulfur loading. Detailed analysis, involving electrochemical impedance spectroscopy, cyclic voltammetry, and density functional theory calculations, is done for the elucidation of the underlying enhancement mechanism by the PEI‐CDots. The strongly localized sulfur species and the promoted Li+ ion conductivity at the cathode–electrolyte interface are revealed to enable high‐performance Li–S batteries with high sulfur loading and large operational current. 相似文献
11.
Yingze Song Wenlong Cai Long Kong Jingsheng Cai Qiang Zhang Jingyu Sun 《Liver Transplantation》2020,10(11)
The lithium–sulfur (Li–S) battery is regarded as a next‐generation energy storage system due to its conspicuous merits in high theoretical capacity (1672 mAh g?1), overwhelming energy density (2600 Wh kg?1), and the cost‐effectiveness of sulfur. However, the practical application of Li–S batteries is still handicapped by a multitude of key challenges, mainly pertaining to fatal lithium polysulfide (LiPS) shuttling and sluggish sulfur redox kinetics. In this respect, rationalizing electrocatalytic processes in Li–S chemistry to synergize the entrapment and conversion of LiPSs is of paramount significance. This review summarizes recent progress and well‐developed strategies of the mediator design toward promoted Li–S chemistry. The current advances, existing challenges, and future directions are accordingly highlighted, aiming at providing in‐depth understanding of the sulfur reaction mechanism and guiding the rational mediator design to realize high‐energy and long‐life Li–S batteries. 相似文献
12.
Ya‐Tao Liu Dian‐Dian Han Lu Wang Guo‐Ran Li Sheng Liu Xue‐Ping Gao 《Liver Transplantation》2019,9(11)
Both the energy density and cycle stability are still challenges for lithium–sulfur (Li–S) batteries in future practical applications. Usually, light‐weight and nonpolar carbon materials are used as the hosts of sulfur, however they struggle on the cycle stability and undermine the volumetric energy density of Li–S batteries. Here, heavy NiCo2O4 nanofibers as carbon‐free sulfur immobilizers are introduced to fabricate sulfur‐based composites. NiCo2O4 can accelerate the catalytic conversion kinetics of soluble intermediate polysulfides by strong chemical interaction, leading to a good cycle stability of sulfur cathodes. Specifically, the S/NiCo2O4 composite presents a high gravimetric capacity of 1125 mAh g?1 at 0.1 C rate with the composite as active material, and a low fading rate of 0.039% per cycle over 1500 cycles at 1 C rate. In particular, the S/NiCo2O4 composite with the high tap density of 1.66 g cm?3 delivers large volumetric capacity of 1867 mAh cm?3, almost twice that of the conventional S/carbon composites. 相似文献
13.
Xiang Hu Yangjie Liu Junxiang Chen Luocai Yi Hongbing Zhan Zhenhai Wen 《Liver Transplantation》2019,9(42)
Potassium‐ion hybrid capacitors (PIHCs) hold the advantages of high‐energy density of batteries and high‐power output of supercapacitors and thus present great promise for the next generation of electrochemical energy storage devices. One of the most crucial tasks for developing a high‐performance PIHCs is to explore a favorable anode material with capability to balance the kinetics mismatch between battery‐type anodes and capacitor‐type cathode. Herein, a reliable route for fabricating sulfur and nitrogen codoped 3D porous carbon nanosheets (S‐N‐PCNs) is reported. Systematic characterizations coupled with kinetics analysis indicate that the doped heteroatoms of sulfur and nitrogen and the amplified graphite interlayer can provide ample structural defects and redox active sites that are beneficial for improving pseudocapacitive activity, enabling fast kinetics toward efficient potassium‐ion storage. The S‐N‐PCNs are demonstrated to exhibit superior potassium storage capability with a high capacity of 107 mAh g?1 at 20 A g?1 and long cycle stability. The as‐developed PIHCs present impressive electrochemical performance with an operating voltage as high as 4.0 V, an energy density of 187 Wh kg?1, a power density of 5136 W kg?1, and a capacity retention of 86.4% after 3000 cycles. 相似文献
14.
Tailored Reaction Route by Micropore Confinement for Li–S Batteries Operating under Lean Electrolyte Conditions
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Hui Wang Brian D. Adams Huilin Pan Liang Zhang Kee Sung Han Luis Estevez Dongping Lu Haiping Jia Jun Feng Jinghua Guo Kevin R. Zavadil Yuyan Shao Ji‐Guang Zhang 《Liver Transplantation》2018,8(21)
Lithium‐sulfur (Li–S) batteries are one of the most promising alternative energy storage systems beyond Li‐ion batteries. However, the sluggish kinetics of the nucleation and growth of the solid discharge product of Li2S/Li2S2 in the lower discharge plateau has been recently identified as a critical hurdle for attaining high specific capacity in Li–S batteries with high sulfur loadings under lean electrolyte conditions. Herein, a new strategy of breaking the charge‐transport bottleneck by successful generation of experimentally verified stable Li2S2 and a reservoir of quasi‐solid lithium polysulfides within the micropores of activated carbon fiber cloth as a high‐sulfur‐loading host is proposed. The developed Li–S cell is capable of delivering a highly sustainable areal capacity of 6.0 mAh cm?2 under lower electrolyte to sulfur ratios (<3.0 mLE gS?1). Micropore confinement leads to generation of solid Li2S2 that enables high utilization of the entire electroactive area by its inherent self‐healing capacity. This strategy opens a new avenue for rational material designs for Li–S batteries under lean electrolyte condition. 相似文献
15.
Ulderico Ulissi Seitaro Ito Seyed Milad Hosseini Alberto Varzi Yuichi Aihara Stefano Passerini 《Liver Transplantation》2018,8(26)
As the theoretical limit of intercalation material‐based lithium‐ion batteries is approached, alternative chemistries based on conversion reactions are presently considered. The conversion of sulfur is particularly appealing as it is associated with a theoretical gravimetric energy density up to 2510 Wh kg?1. In this paper, three different carbon‐iron disulfide‐sulfur (C‐FeS2‐S) composites are proposed as alternative positive electrode materials for all‐solid‐state lithium‐sulfur batteries. These are synthesized through a facile, low‐cost, single‐step ball‐milling procedure. It is found that the crystalline structure (evaluated by X‐ray diffraction) and the morphology of the composites (evaluated by scanning electron microscopy) are greatly influenced by the FeS2:S ratio. Li/LiI‐Li3PS4/C‐FeS2‐S solid‐state cells are tested under galvanostatic conditions, while differential capacity plots are used to discuss the peculiar electrochemical features of these novel materials. These cells deliver capacities as high as 1200 mAh g(FeS2+S)?1 at the intermediate loading of 1 mg cm?2 (1.2 mAh cm?2), and up to 3.55 mAh cm?2 for active material loadings as high as 5 mg cm?2 at 20 °C. Such an excellent performance, rarely reported for (sulfur/metal sulfide)‐based, all solid‐state cells, makes these composites highly promising for real application where high positive electrode loadings are required. 相似文献
16.
Rui Wang Jinlong Yang Xin Chen Yan Zhao Wenguang Zhao Guoyu Qian Shunning Li Yinguo Xiao Hao Chen Yusheng Ye Guangmin Zhou Feng Pan 《Liver Transplantation》2020,10(9)
The lithium–sulfur (Li–S) battery is considered a promising candidate for the next generation of energy storage system due to its high specific energy density and low cost of raw materials. However, the practical application of Li–S batteries is severely limited by several weaknesses such as the shuttle effect of polysulfides and the insulation of the electrochemical products of sulfur and Li2S/Li2S2. Here, by doping nitrogen and integrating highly dispersed cobalt catalysts, a porous carbon nanocage derived from glucose adsorbed metal–organic framework is developed as the host for a sulfur cathode. This host structure combines the reported positive effects, including high conductivity, high sulfur loading, effective stress release, fast lithium‐ion kinetics, fast interface charge transport, fast redox of Li2Sn, and strong physical/chemical absorption, achieving a long cycle life (86% of capacity retention at 1C within 500 cycles) and high rate performance (600 mAh g?1 at 5C) for a Li–S battery. By combining experiments and density functional theoretical calculations, it is demonstrated that the well‐dispersed cobalt clusters play an important role in greatly improving the diffusion dynamics of lithium, and enhance the absorption and conversion capability of polysulfides in the host structure. 相似文献
17.
Xiaoxue Lv Tianyu Lei Bojun Wang Wei Chen Yu Jiao Yin Hu Yichao Yan Jianwen Huang Junwei Chu Chaoyi Yan Chunyang Wu Jianwei Wang Xiaobin Niu Jie Xiong 《Liver Transplantation》2019,9(40)
Due to unprecedented features including high‐energy density, low cost, and light weight, lithium–sulfur batteries have been proposed as a promising successor of lithium‐ion batteries. However, unresolved detrimental low Li‐ion transport rates in traditional carbon materials lead to large energy barrier in high sulfur loading batteries, which prevents the lithium–sulfur batteries from commercialization. In this report, to overcome the challenge of increasing both the cycling stability and areal capacity, a metallic oxide composite (NiCo2O4@rGO) is designed to enable a robust separator with low energy barrier for Li‐ion diffusion and simultaneously provide abundant active sites for the catalytic conversion of the polar polysulfides. With a high sulfur‐loading of 6 mg cm?2 and low sulfur/electrolyte ratio of 10, the assembled batteries deliver an initial capacity of 5.04 mAh cm?2 as well as capacity retention of 92% after 400 cycles. The metallic oxide composite NiCo2O4@rGO/PP separator with low Li‐ion diffusion energy barrier opens up the opportunity for lithium–sulfur batteries to achieve long‐cycle, cost‐effective operation toward wide applications in electric vehicles and electronic devices. 相似文献
18.
Hong Yuan Hong‐Jie Peng Bo‐Quan Li Jin Xie Long Kong Meng Zhao Xiao Chen Jia‐Qi Huang Qiang Zhang 《Liver Transplantation》2019,9(1)
Rechargeable lithium–sulfur batteries have attracted tremendous scientific attention owing to their superior energy density. However, the sulfur electrochemistry involves multielectron redox reactions and complicated phase transformations, while the final morphology of solid‐phase Li2S precipitates largely dominate the battery's performance. Herein, a triple‐phase interface among electrolyte/CoSe2/G is proposed to afford strong chemisorption, high electrical conductivity, and superb electrocatalysis of polysulfide redox reactions in a working lithium–sulfur battery. The triple‐phase interface effectively enhances the kinetic behaviors of soluble lithium polysulfides and regulates the uniform nucleation and controllable growth of solid Li2S precipitates at large current density. Therefore, the cell with the CoSe2/G functional separator delivers an ultrahigh rate cycle at 6.0 C with an initial capacity of 916 mAh g?1 and a capacity retention of 459 mAh g?1 after 500 cycles, and a stable operation of high sulfur loading electrode (2.69–4.35 mg cm?2). This work opens up a new insight into the energy chemistry at interfaces to rationally regulate the electrochemical redox reactions, and also inspires the exploration of related energy storage and conversion systems based on multielectron redox reactions. 相似文献
19.
Direct Growth of Flower‐Like δ‐MnO2 on Three‐Dimensional Graphene for High‐Performance Rechargeable Li‐O2 Batteries
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Shuangyu Liu Yunguang Zhu Jian Xie Ying Huo Hui Ying Yang Tiejun Zhu Gaoshao Cao Xinbing Zhao Shichao Zhang 《Liver Transplantation》2014,4(9)
A challenge still remains to develop high‐performance and cost‐effective air electrode for Li‐O2 batteries with high capacity, enhanced rate capability and long cycle life (100 times or above) despite recent advances in this field. In this work, a new design of binder‐free air electrode composed of three‐dimensional (3D) graphene (G) and flower‐like δ‐MnO2 (3D‐G‐MnO2) has been proposed. In this design, graphene and δ‐MnO2 grow directly on the skeleton of Ni foam that inherits the interconnected 3D scaffold of Ni foam. Li‐O2 batteries with 3D‐G‐MnO2 electrode can yield a high discharge capacity of 3660 mAh g?1 at 0.083 mA cm?2. The battery can sustain 132 cycles at a capacity of 492 mAh g?1 (1000 mAh gcarbon ?1) with low overpotentials under a high current density of 0.333 mA cm?2. A high average energy density of 1350 Wh Kg?1 is maintained over 110 cycles at this high current density. The excellent catalytic activity of 3D‐G‐MnO2 makes it an attractive air electrode for high‐performance Li‐O2 batteries. 相似文献
20.
Lithium–sulfur (Li‐S) batteries are a promising next‐generation energy‐storage system, but the polysulfide shuttle and dendritic Li growth seriously hinder their commercial viability. Most of the previous studies have focused on only one of these two issues at a time. To address both the issues simultaneously, presented here is a highly conductive, noncarbon, 3D vanadium nitride (VN) nanowire array as an efficient host for both sulfur cathodes and lithium‐metal anodes. With fast electron and ion transport and high porosity and surface area, VN traps the soluble polysulfides, promotes the redox kinetics of sulfur cathodes, facilitates uniform nucleation/growth of lithium metal, and inhibits lithium dendrite growth at an unprecedented high current density of 10 mA cm?2 over 200 h of repeated plating/stripping. As a result, VN‐Li||VN‐S full cells constructed with VN as both an anode and cathode host with a negative to positive electrode capacity ratio of only ≈2 deliver remarkable electrochemical performance with a high Coulombic efficiency of ≈99.6% over 850 cycles at a high 4 C rate and a high areal capacity of 4.6 mA h cm?2. The strategy presented here offers a viable approach to realize high‐energy‐density, safe Li‐metal‐based batteries. 相似文献