Preparation of LLZO template by electrospinning and study on flexible composite solid electrolyte based on 3D Li6.4La3Zr2Al0.2O12 framework

Abstract

In this work, we innovatively used the electrospinning method to prepare templates, which were then used in the template method to prepare Li6.4La3Zr2Al0.2O12(LLZO). By combining the advantages of electrospinning and template methods, we greatly expanded the source of template materials for the template method. Different template materials combined with electrospinning can obtain LLZO with different structures and performance. At the same time, we innovatively combined PVDF-based solid electrolyte with high concentration of LiTFSI with 3D LLZO framework. Using the complex formed by N-methyl pyrrolidone (NMP) and lithium ion (Li+) as a charge carrier, unique lithium ion migration channels formed by high-concentration LiTFSI, and the joint effect of high-content LLZO, we obtained a composite solid electrolyte with excellent performance. It has high mechanical strength (1.4 MPa) and high Young's modulus (6.4 MPa), which effectively inhibits the growth of lithium dendrites. In addition, the composite solid electrolyte exhibits excellent ion conductivity at room temperature (2.07 ×10−4 S cm−1), and a lithium symmetric battery can operate stably for at least 1000 h at 50 ℃. After 100 cycles at a current density of 0.5 C at 50 ℃, the remaining specific capacity of LiFePO4 | 3D LLZO·CSE | Li was 141.9 mAh g−1, and the capacity retention rate was 96.4%. Our research results show that this low-cost LLZO template manufacturing method, combined with the excellent performance of the obtained composite solid electrolyte, has great potential in energy storage direction.