JOURNAL OF POWER SOURCES
·
2017
·
IF 6.395
Nanping Deng,Weimin Kang,Jingge Ju,Lanlan Fan,Xupin Zhuang,Xiaomin Ma,Hongsheng He,Yixia Zhao,Bowen Cheng
The honeycomb-like hierarchical porous carbon nanofibers (PCNFs)-carbon nanotubes (CNTs)-sulfur(S) composite electrode is successfully desgined and prepared through ball-milling and heating method, in which the PCNFs are carbonized from fibers in the membrane composed of Polyvinyl Alcohol and Polytetrafluoroethylene by electro-blown spinning technology. The prepared PCNFs-CNTs-S composite are regarded as cathode for lithium-sulfur battery . The tailored porous structure and CNTs in the composite facilitate construction of a high electrical conductive pathway and store more S/polysulfides, and the dissoluble loss of intermediate S species in electrolyte can also be restrained because of acidized PVA-based porous carbon nanofibers. Meanwhile, the porous strcucture and CNTs can effectively alleviate volume changes in battery cycling process. Moreover, the presence of LiNO 3 in electrolyte helps the electrochemical oxidation of Li 2 S and LiNO 3 -derived surface film effectively suppresses the migration of soluble polysulfide to the Li anode surface . Therefore, the obtained PCNFs-CNTs-S cathode exhibits excellent performance in Li-S battery with a high initial discharge capacity as high as 1302.9 mAh g −1 , and super stable capacity retention with 809.1 mAh g −1 after 300 cycles at the current density of 837.5 mA g −1 (0.5 C). And the rate capability of PCNFs-CNTs-S electrode is much better than those of CNTs-S and PCNFs-S electrodes.
研究领域:
材料科学
·
能源存储技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2014
·
IF 5.211
Xiaoyan Liu,Zhongqiang Shan,Kunlei Zhu,Jiangyong Du,Qiwei Tang,Jianhua Tian
Lithium sulfur batteries have brought significant advancement to the current state-of-art battery technologies due to their high theoretical specific energy of 1675 mAh g −1 . However, the rapid capacity degradation, mainly caused by polysulfide dissolution, remains a significant challenge prior to practical applications. In this work, a sulfur cathode modified by bifunctional nafion/γ-Al 2 O 3 membrane has been successfully prepared, which can remarkably immobilize the polysulfides within the unique cathode structure due to its ions selectivity and absorbent capacity. A high initial discharge capacity of 1448.0 mAh g −1 can be achieved at 1C and 788.6 mAh g −1 preserved after 200 cycles, indicating a slow degradation. Furthermore, the coulombic efficiency maintains as high as 97% during cycling. The excellent electrochemical properties can be attributed to the bifunctional and stable membrane which can dramatically reduce the shuttle effect and keep integrated even after charging–discharging for 200 cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Bingbin Wu,Xiaoyu Jiang,Lifen Xiao,Wenhua Zhang,Jiaxin Pan,Xinping Ai,Hanxi Yang,Yuliang Cao
Sulfur has the highest redox capacity in all the solid electrode materials but its application for Li-S batteries is restricted by its poor cycleability due to the dissolution of its polysulfide intermediates produced during charge and discharge reactions. To solve this problem, we proposed a new strategy to suppress the dissolution of the polysulfide intermediates and the agglomeration of the discharge products through surface-modification of the sulfur electrode by in-situ electropolymerized poly(N-methylpyrrole) (PNMP). The PNMP-modified sulfur electrode exhibits stable surface morphology during charge and discharge, effectively depressing the structural collapse of the sulfur electrode. The charge-discharge measurements reveal that the PNMP-modified S/C electrode can deliver the same high reversible capacity as the bare electrode but demonstrate a much improved cycling stability with excellent capacity retention of 78.1% over 200 cycles with respect to the discharge capacity in the third cycle, considerably higher than that of the bare electrode (59.8%). In addition, this surface modification method is simple and affordable, providing a feasible way for improving the long-term cycleability of Li-S batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science
·
2022
·Vol. 9
·期 26
·2201881
·
IF 17.521
Zhengmin Zhang,Jiangyang Mo,Peng Yu,Lanxiang Feng,Yu Wang,Yuyuan Lu,Wei Yang
The electrochemical performance of lithium–sulfur batteries is fundamentally determined by the structural and mechanical stability of their composite sulfur cathodes. However, the development of cost-effective strategies for realizing robust hierarchical composite electrode structures remains highly challenging due to uncontrollable interactions among the components. The present work addresses this issue by proposing a type of self-assembling electrode slurry based on a well-designed two-component (polyacrylonitrile and polyvinylpyrrolidone) polar binder system with carbon nanotubes that forms hierarchical porous structures via optimized water-vapor-induced phase separation. The electrode skeleton is a highly robust and flexible electron-conductive network, and the porous structure provides hierarchical ion-transport channels with strong polysulfide trapping capability. Composite sulfur cathodes prepared with a sulfur loading of 4.53 mg cm −2 realize a very stable specific capacity of 485 mAh g −1 at a current density of 3.74 mA cm −2 after 1000 cycles. Meanwhile, a composite sulfur cathode with a high sulfur loading of 14.5 mg cm −2 in a lithium–sulfur pouch cell provides good flexibility and delivers a high capacity of 600 mAh g −1 at a current density of 0.72 mA cm −2 for 78 cycles.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 41
·2104433
·
IF 18.808
Biyu Jin,Dongyun Wang,Juan Zhu,Hongyu Guo,Yang Hou,Xiang Gao,Jianguo Lu,Xiaoli Zhan,Xiaojun He,Qinghua Zhang
Large volume change, poor conductivity, and electrolyte soluble active materials intermediates have long been daunting challenges for sulfur, silicon, and silicon oxides electrode materials. A self-healable polyelectrolyte binder is exploited by crosslinking polydopamine, phytic acid and poly(acrylamide- co -2-(Dimethylamino)ethyl acrylate) in situ at room temperature through reconfigurable hydrogen bonds and ionic bonds. Therefore, the crosslinked binder network can readily recover its mechanical strength without extra stimulus, offering a reliable strategy for electrodes plagued by large volume change issue. Sulfur (S) and silicon (Si) electrodes prepared using the self-healable polyelectrolyte binder can effectively maintain its structure integrity after long-term cycling. In addition, the polar groups, especially negative-charged phosphate ions empower the polyelectrolyte binder as a more effective binder than commercial poly(vinylidene fluoride) in terms of restraining lithium polysulfides shuttling and accelerating lithium ion transportation, as evidenced by in situ UV-visible spectroscopy, density functional theory calculation and cyclic voltammetry. Consequently, high-active materials loading S cathode, Si and SiO-graphite anodes all achieve high area capacity and satisfying cycling stability by conveniently applying the advanced binder. This facile strategy for constructing multiuse binder illuminates versatile development in many energy storage systems.
研究领域:
材料科学
·
电化学
·
储能系统
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）