Key points are not available for this paper at this time.
Abstract Composite solid electrolytes (CSEs) are promising candidates for solid‐state lithium metal batteries. However, the poor cross‐phase Li + transport restricts the rate performance and cycle life of the batteries. Herein, we revealed the Li + percolation behavior in poly(vinylidene fluoride) (PVDF)‐based CSEs with Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 filler. The de‐coordination barrier from Li + clusters determines interfacial Li + transport capability. We then employed a designed N ‐methyl‐2,2,2‐trifluoroacetamide (NMTFA) ligand to lower the de‐coordination energy and activate interfacial Li + exchange. The ionic conductivity is therefore increased from 3.32 × 10 −4 to 7.30 × 10 −4 S cm −1 . By tracking the 6 Li and 7 Li substitution process, it was identified that the proportion of interfacial Li + transport increases from 11% to 26%. The NMTFA also contributes to the formation of inorganic‐rich interphases with electrodes. As a result, the Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 solid‐state batteries exhibit ultra‐long lifespans of 2400, 3000, and 10 000 times at 2, 5, and 10C, respectively, as well as achieve 1000 cycles at 50 °C and 300 cycles at −30 °C. This work highlights the critical role of interfacial Li + transport for the CSEs with “polymer‐Li + clusters‐filler” configuration to realize high‐rate and long‐cycling solid‐state lithium batteries.
Zhu et al. (Fri,) studied this question.