摘要
Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ionic conductivity and slow Li+transference.Herein,based on the“binary electrolytes”of poly(vinylidene fluoride-chlorotrifluoroethylene)(P(VDF-CTFE))and lithium salt(LiTFSI),a kind of eutectogel hybrid electrolytes(EHEs)with high Li+transference number was developed via tuning the spontaneous coupling of charge and vacated space generated by Li-cation diffusion utilizing the Li6.4La3Zr1.4Ta0.6O12(LLZTO)dopant.LLZTO doping promotes the dissociation of lithium salt,increases Li+carrier density,and boosts ion jumping and the coordination/decoupling reactions of Li+.As a result,the optimized EHEs-10%possess a high Li-transference number of 0.86 and a high Li+conductivity of 3.2×10–4 S·cm–1 at room temperature.Moreover,the prepared EHEs-10%composite solid electrolyte presents excellent lithiumphilic and compatibility,and can be tested stably for 1,200 h at 0.3 mA·cm–2 with assembled lithium symmetric batteries.Likewise,the EHEs-10%films match well with high-loading LiFePO4 and LiCoO2 cathodes(>10 mg·cm–2)and exhibit remarkable interface stability.Particularly,the LiFePO4//EHEs-10%//Li and LiCoO2//EHEs-10%//Li cells deliver high rate performance of 118 mAh·g–1 at 1 C and 93.7 mAh·g–1 at 2 C with coulombic efficiency of 99.3%and 98.1%,respectively.This work provides an in-depth understanding and new insights into our design for polymer electrolytes with fast Li+diffusion.
基金
This work was supported by the International Cooperation Projects of Sichuan Provincial Department of Science and Technology(No.2021YFH0126)
Quzhou Science and Technology Bureau Project(No.2021D006)
the Fundamental Research Funds for the Central Universities(No.A030202063008029)
The China Postdoctoral Science Foundation(Nos.2021T140433,2020M683408)
the Natural Science Foundation of Shaanxi Province(No.2021JQ-538).
