摘要
With increasing demand on energy density of lithium-ion battery,wide electrochemical window and safety performance are the crucial request for next generation electrolyte.Gel-electrolyte as a pioneer for electrolyte solidization development aims to solve the safety and electrochemical window problems.However,low ionic conductivity and poor physical performance prohibit its further application.Herein,a fast-ionic conductor(Li_(2.64)(Sc_(0.9)Ti_(0.1))_(2)(PO_(4))_(3))(LSTP)was added into poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)base gel-electrolyte to enhance mechanical properties and ionic conductivity.Evidences reveal that LSTP was able to weaken interforce between polymer chains,which increased the ionic conductibility and decreased interface resistance during the cycling significantly.The obtained LiFePO_(4)/hybrid gel-electrolyte/Li-metal coin cell exhibited excellent rate capacity(145 mA·h/g at 1C,95 mA·h/g at 3C,28℃)which presented a potential that can be comparable with commercialized liquid electrolyte system.
随着锂离子电池对能量密度要求的不断提高,更宽的电化学窗口和更高的安全性能将是下一代电解质发展的重要方向。凝胶电解质作为电解质固态化发展研究的过渡阶段,在解决安全性问题、拓宽电化学窗口等方面有着良好的应用前景。然而,较低的离子电导率和较差的力学性能阻碍了凝胶电解质的进一步应用。为此,将一种快离子导体Li_(2.64)(Sc_(0.9)Ti_(0.1))_(2)(PO_(4))_(3)(LSTP)添加到聚偏氟乙烯-六氟丙烯基(PVDF-HFP)凝胶电解质中,以提高其力学性能和离子导电性。结果表明,LSTP能够削弱聚合物链间的相互作用力,加强链的热振动,显著提高离子导电性,降低循环过程中的界面电阻。所制备的混合凝胶电解质锂金属电池具有优异的倍率容量(在28℃时1C下为145 mA·h/g,3C下为95 mA·h/g),展现出了可与商品化液体电解质体系相媲美的潜力。
作者
WANG Zhen-yu
LI Cong
HUANG Ying-de
HE Zhen-jiang
YAN Cheng
MAO Jing
DAI Ke-hua
ZHENG Jun-chao
王振宇;李聪;黄英德;贺振江;闫澄;毛景;代克化;郑俊超(School of Metallurgy and Environment,Central South University,Changsha 410083,China;National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals,Central South University,Changsha 410083,China;Engineering Research Center of the Ministry of Education for Advanced Battery Materials,Central South University,Changsha 410083,China;School of Mechanical,Medical and Process Engineering,Queensland University of Technology,Brisbane,Queensland 4001,Australia;School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China;College of Chemistry,Tianjin Normal University,Tianjin 300387,China)
基金
Projects(51974368,51774333) supported by the National Natural Science Foundation of China
Project(2020JJ2048) supported by the Hunan Provincial Natural Science Foundation of China。
