Integrated manufacturing of REciclable multi-material COmposites for the TRANSport sector
Constructing Ion Bridges With Competitive Coordination Effects to Promote Li+ Conduction in Solid?State Electrolytes for High?Performance Lithium Metal Batteries
By constructing ion bridges with competitive coordination effects on the LLZTO surface, the coordination strength of Li+ in the composite electrolyte was weakened, suppressing the space charge layer formation at the PVDF?HFP/LLZTO interface and significantly enhancing Li+ transport kinetics. This ultimately resulted in an electrolyte with high ionic conductivity, thereby enabling solid?state lithium metal batteries with high cycling stability.ABSTRACTComposite solid electrolytes (CSEs) based on poly(vinylidene fluoride)?co?hexafluoropropylene (PVDF?HFP) and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) are considered among the most promising SEs for achieving high?energy?density solid?state batteries. However, low ionic conductivity and poor interfacial compatibility pose significant challenges for their practical applications. Herein, a strategy involving the construction of LixTaOxF5?x (LTOF) ion bridges with competitive coordination effects on the LLZTO surface is proposed. This approach alleviates restrictions on Li+ transport and enhances Li+ transport kinetics. The introduction of LTOF weakens Li+ coordination strength, suppresses electron localization at the LLZTO/PVDF?HFP interface, and simultaneously reduces PVDF?HFP crystallinity. This creates multiple efficient Li+ transport pathways and an interphase with excellent compatibility. Consequently, the prepared electrolyte exhibits a high ionic conductivity of 1.21 mS cm?1. Attributing to easier lithium salt dissociation, the solid electrolyte interface enriched with inorganic components, e.g. LiF/Li3N/Li2S, enables the Li|CSE?9TF|Li cell to maintain stable plating/stripping for over 1100 h at a current density of 0.8 mA cm?2. The assembled LiFePO4||Li cells deliver high capacity retention (93.4%) and approaching 100% coulombic efficiency after 1000 cycles at 1C. This work proposes a strategy for regulating the coordination environment and improving interfacial compatibility through surface oxyhalide layers, facilitating new progress in the practical application of CSEs.
» Publication Date: 02/02/2026
This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement Nº 768737
