Affiliation:
1. School of Materials Science and Engineering Shandong University of Technology Zibo 255000 P. R. China
2. Shandong Silicon Nano New Material Technology Co. LTD Zibo 255000 P. R. China
Abstract
AbstractThe commercialization of silicon anode for lithium‐ion batteries has been hindered by severe structure fracture and continuous interfacial reaction against liquid electrolytes, which can be mitigated by solid‐state electrolytes. However, rigid ceramic electrolyte suffers from large electrolyte/electrode interfacial resistance, and polymer electrolyte undergoes poor ionic conductivity, both of which are worsened by volume expansion of silicon. Herein, by dispersing Li1.3Al0.3Ti1.7(PO4)3 (LATP) into poly(vinylidene fluoride)‐hexafluoropropylene (PVDF‐HFP) and poly(ethylene oxide) (PEO) matrix, the PVDF‐HFP/PEO/LATP (PHP‐L) solid‐state electrolyte with high ionic conductivity (1.40 × 10−3 S cm−1), high tensile strength and flexibility is designed, achieving brilliant compatibility with silicon nanosheets. The chemical interactions between PVDF‐HFP and PEO, LATP increase amorphous degree of polymer, accelerating Li+ transfer. Good flexibility of the PHP‐L contributes to adaptive structure variation of electrolyte with silicon expansion/shrinkage, ensuring swift interfacial ions transfer. Moreover, the solid membrane with high tensile limits electrode structural degradation and eliminates continuous interfacial growth to form stable 2D solid electrolyte interface (SEI) film, achieving superior cyclic performance to liquid electrolytes. The Si//PHP‐L15//LiFePO4 solid‐state full‐cell exhibits stable lithium storage with 81% capacity retention after 100 cycles. This work demonstrates the effectiveness of composite solid electrolyte in addressing fundamental interfacial and performance challenges of silicon anodes.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shandong Province
Zibo City Integration Development Project
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry