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141.
Enhancing the Electrochemical Performance of the LiMn2O4 Hollow Microsphere Cathode with a LiNi0.5Mn1.5O4 Coated Layer
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Wei Liu Dr. Jun Liu Kunfeng Chen Dr. Shaomin Ji Yanling Wan Prof. Dr. Yichun Zhou Prof. Dr. Dongfeng Xue Prof. Dr. Peter Hodgson Dr. Yuncang Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(3):824-830
Spinel cathode materials consisting of LiMn2O4@LiNi0.5Mn1.5O4 hollow microspheres have been synthesized by a facile solution‐phase coating and subsequent solid‐phase lithiation route in an atmosphere of air. When used as the cathode of lithium‐ion batteries, the double‐shell LiMn2O4@LiNi0.5Mn1.5O4 hollow microspheres thus obtained show a high specific capacity of 120 mA h g?1 at 1 C rate, and excellent rate capability (90 mAhg?1 at 10 C) over the range of 3.5–5 V versus Li/Li+ with a retention of 95 % over 500 cycles. 相似文献
142.
Carbonized Polyacrylonitrile‐Stabilized SeSx Cathodes for Long Cycle Life and High Power Density Lithium Ion Batteries
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Chao Luo Yujie Zhu Yang Wen Jingjing Wang Chunsheng Wang 《Advanced functional materials》2014,24(26):4082-4089
A facile synthesis of selenium sulfide (SeSx)/carbonized polyacrylonitrile (CPAN) composites is achieved by annealing the mixture of SeS2 and polyacrylonitrile (PAN) at 600 °C under vacuum. The SeSx molecules are confined by N‐containing carbon (ring) structures in the carbonized PAN to mitigate the dissolution of polysulfide and polyselenide intermediates in carbonate‐based electrolyte. In addition, formation of solid electrolyte interphase (SEI) on the surface of SeSx/CPAN electrode in the first cycle further prevents polysulfide and polyselenide intermediates from dissolution. The synergic restriction of SeSx by both CPAN matrix and SEI layer allows SeSx/CPAN composites to be charged and discharged in a low‐cost carbonate‐based electrolyte (LiPF6 in EC/DEC) with long cycling stability and high rate capability. At a current density of 600 mA g?1, it maintains a reversible capacity of 780 mAh g?1 for 1200 cycles. Moreover, it retains 50% of the capacity at 60 mA g?1 even when the current density increases to 6 A g?1. The superior electrochemical performance of SeSx/CPAN composite demonstrates that it is a promising cathode material for long cycle life and high power density lithium ion batteries. This is the first report on long cycling stability and high rate capability of selenium sulfide‐based cathode material. 相似文献
143.
Chen Zhao Gui‐Liang Xu Tianshou Zhao Khalil Amine 《Angewandte Chemie (International ed. in English)》2020,59(40):17634-17640
Electrolyte modulation simultaneously suppresses polysulfide the shuttle effect and lithium dendrite formation of lithium–sulfur (Li‐S) batteries. However, the sluggish S redox kinetics, especially under high S loading and lean electrolyte operation, has been ignored, which dramatically limits the cycle life and energy density of practical Li‐S pouch cells. Herein, we demonstrate that a rational combination of selenium doping, core–shell hollow host structure, and fluorinated ether electrolytes enables ultrastable Li stripping/plating and essentially no polysulfide shuttle as well as fast redox kinetics. Thus, high areal capacity (>4 mAh cm?2) with excellent cycle stability and Coulombic efficiency were both demonstrated in Li metal anode and thick S cathode (4.5 mg cm?2) with a low electrolyte/sulfur ratio (10 μL mg?1). This research further demonstrates a durable Li‐Se/S pouch cell with high specific capacity, validating the potential practical applications. 相似文献
144.
Dr. Anqiang Pan Ting Zhu Hao Bin Wu Prof. Xiong Wen Lou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(2):494-500
Nanosheet‐assembled hierarchical V2O5 hollow microspheres are successfully obtained from V‐glycolate precursor hollow microspheres, which in turn are synthesized by a simple template‐free solvothermal method. The structural evolution of the V‐glycolate hollow microspheres has been studied and explained by the inside‐out Ostwald‐ripening mechanism. The surface morphologies of the hollow microspheres can be controlled by varying the mixture solution and the solvothermal reaction time. After calcination in air, hierarchical V2O5 hollow microspheres with a high surface area of 70 m2 g?1 can be obtained and the structure is well preserved. When evaluated as cathode materials for lithium‐ion batteries, the as‐prepared hierarchical V2O5 hollow spheres deliver a specific discharge capacity of 144 mA h g?1 at a current density of 100 mA g?1, which is very close to the theoretical capacity (147 mA h g?1) for one Li+ insertion per V2O5. In addition, excellent rate capability and cycling stability are observed, suggesting their promising use in lithium‐ion batteries. 相似文献
145.
Jie Li Bo Peng Yapeng Li Lai Yu Gongrui Wang Dr. Liang Shi Prof. Genqiang Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(57):13094-13098
Sodium-ion batteries have attracted tremendous attention due to their much lower cost and similar working principle compared with lithium-ion batteries, which have been invited great expectation as energy storage devices in grid-level applications. The sodium superionic conductor Na3V2(PO4)3 has been considered as a promising cathode candidate; however, its intrinsic low electronic conductivity results in poor rate performance and unsatisfactory cycling performance, which severely impedes its potential for practical applications. Herein, we developed a facile one-pot strategy to construct dual carbon-protected hybrid structure composed of carbon coated Na3V2(PO4)3 nanoparticles embedded with carbon matrix with excellent rate performance, superior cycling stability and ultralong lifespan. Specifically, it can deliver an outstanding rate performance with a 51.5 % capacity retention from 0.5 to 100 C and extraordinary cycling stability of 80.86 % capacity retention after 6000 cycles at the high rate of 20 C. The possible reasons for the enhanced performance could be understood as the synergistic effects of the strengthened robust structure, facilitated charge transfer kinetics, and the mesoporous nature of the Na3V2(PO4)3 hybrid structure. This work provides a cost-effective strategy to effectively optimize the electrochemical performance of a Na3V2(PO4)3 cathode, which could contribute to push forward the advance of its practical applications. 相似文献
146.
Yunhong Wei Mi Zhang Li Yuan Boya Wang Hongmei Wang Qian Wang Yun Zhang Junling Guo Hao Wu 《Advanced functional materials》2021,31(41):2103456
Metal nitride-based heterostructures have been effective polysulfide mediators in lithium-sulfur batteries. Still, these heterostructures developed so far primarily rely on high-temperature ammonification with corrosive NH3 or synthetic nitrogen-contained reagents as nitrogen sources, casting potential environmental hazards, and additional technical challenges. Herein, a multichambered carbon nanofiber host architecture with an in-built TiN/TiO2 heterostructure configuration derived from natural structured proteins is designed. The TiN/TiO2 heterostructure is spontaneously generated in the carbon nanofibers upon the pyrolysis of inborn N-enriched bio-precursor accompanied by thermal-induced topochemical self-nitridation without any additional nitrogen sources. Ex-/in situ experiments with theoretical calculations identify the strong trapping and enhanced charge transfer on the polar heterointerfaces, synchronously realizing the immobilization–diffusion–transformation of polysulfides. The multichambered host framework with rich internal voids and enhanced conductivity promise the accommodation of liquid Li2S6 catholyte, meanwhile ensuring that the cells can work with lean electrolyte. Consequently, the resulted Li-polysulfide cell exhibits an ultralow capacity decay of 0.023% per cycle over 500 cycles and considerable areal capacity (≈6 mAh cm–2) at high S loading (5.8 mg cm–2). Importantly, an ingenious configurated full battery based on lithiated silicon anode and polysulfide cathode is competent to achieve appreciable cyclability with high energy density even under a low negative/positive capacity ratio (≈1.18). 相似文献
147.
Jing-Jing Fan Peng Dai Chen-Guang Shi Yanfen Wen Chen-Xu Luo Jian Yang Cun Song Ling Huang Shi-Gang Sun 《Advanced functional materials》2021,31(17):2010500
The electrolyte additive plays an important role in determining the crucial properties of batteries such as cycling stability and safety. Compared to material development, research on electrolyte and interphase is still in the early stage for sodium ion batteries (SIBs). Herein, for the first time, succinic anhydride (SA) is investigated as a synergistic filming additive to fluoroethylene carbonate (FEC), and the lifespan of the dual-additive Na/Na0.6Li0.15Ni0.15Mn0.55Cu0.15O2 (NLNMC) cell is significantly improved, maintaining capacity retention of 87.2% over 400 cycles at 1 C rate. For comparison, the batteries with only one of the two additives or without any additive show much inferior electrochemical performance. After the addition of SA, the interphase layer on the surface of cycled NLNMC material becomes uniform and stable, which contains more oxygen-rich organic species and less NaF. Additionally, the addition of SA also has an impact on the interphase layer in the sodium anode part as indicated by electrochemical impedance spectroscopy (EIS) and energy dispersive spectrometer (EDS) results. Moreover, the online differential electrochemical mass spectrometry (OEMS) tests show the dual-additive cell has less CO2 generation during the initial two cycles compared to that with only FECs which demonstrates another advantage of SA for practical application. 相似文献
148.
锂离子动力电池,作为动力源,要求其具有较高的比容量、倍率性能、热稳定性及优异的循环性能。静电纺丝技术是一种新型纳米纤维制备技术,因其制备的纳米纤维膜具有比表面积大和孔隙率高等特点,近年来在锂离子电池领域得到了广泛应用,有望成为大幅改善锂离子动力电池性能的关键技术。基于锂离子动力电池的特性,当前静电纺丝技术主要用于制备高孔隙率的纳米纤维膜、高分子共混膜及无机-高分子复合膜等隔膜材料以提高隔膜的机械性能和热稳定性;此外,静电纺丝技术还被用于改善磷酸铁锂等聚阴离子型正极材料及石墨负极材料的电化学性能。本文还针对上述研究中存在的问题,提出了未来静电纺丝技术在锂离子动力电池中应用的可改进的研究方案。 相似文献
149.
Electron field emission from ZnO self-organized nanostructures and doped ZnO:Ga nanostructured films
V.A. Karpyna A.A. Evtukh V.I. Lazorenko V.D. Khranovskyy D.A. Fedorchenko 《Microelectronics Journal》2009,40(2):229-24568
Self-organized ZnO nanostructures were grown by thermal decomposition of metalorganic precursors as well as by carbothermal reduction process. Nanostructured undoped and gallium-doped ZnO nanostructured films were deposited by plasma-enhanced chemical vapor deposition from metalorganic compounds. Electron field emission follows Fowler-Nordheim equation. Efficient electron emission was obtained from self-organized nanostructures due to their geometric shape. Enhanced field emission from ZnO:Ga nanostructured films in comparison with undoped ZnO films is obliged to lowering work function at doping by gallium. 相似文献
150.