Building cross-phase ion transport channels between ceramic and polymer for highly conductive composite solid-state electrolyte
Liang Zhao, Xiangnan Yu, Junyu Jiao, Xin Song, Xing Cheng, Ming Liu, Liliang Wang, Jiaxin Zheng, Wei Lv, Guiming Zhong, Yan‐Bing He, Feiyu Kang
Abstract
The large energy barrier for lithium-ion transport across polymer-ceramic interface limits the significant improvement of the ionic conductivity of composite solid-state electrolytes (CSEs). Herein, we construct high-efficiency cross-phase ion transport channels (CITCs) between poly(vinylidene fluoride) (PVDF) and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) by cross-linking reaction of 3-methacryloxypropyltrimethoxysilane (MPS) with dehydrofluorinated PVDF and LLZTO. The CITCs enhance the lithium-ion concentration at the PVDF-LLZTO interface and provide continuous low-barrier lithium-ion pathways to achieve a quite high ionic conductivity (8.7 × 10−4 S cm−1) of CSE (PML). Furthermore, we quantitatively reveal that the CITCs increase the proportion of interfacial lithium-ion transport in CSEs from 4.2% to 26.2%, which further promotes the lithium-ion transport contribution of LLZTO from 8.6% to 18.2%. LiNi0.8Co0.1Mn0.1O2|PML|Li solid-state batteries can stably operate for 1,700 cycles at 2C and 25°C, and pouch cells also exhibit excellent cycling and safety performance. This work reveals that cross-phase lithium-ion transport in CSEs determines their ionic conductivity.