PVDF-HFP based polymer electrolytes with high Li+ transference number enhancing the cycling performance and rate capability of lithium metal batteries

Lithium metal batteries are confronted with safety issues in liquid electrolyte systems owing to rapid growth of lithium dendrite and uneven lithium deposition. Exploration of gel polymer electrolytes (GPEs) with excellent ionic conductivity and high Li+ migration number is a possible strategy to replace liquid electrolyte. Herein, a high-powered GPEs relied on poly (vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) modified by polymer polyethylene glycol (PEG) and lithium montmorillonite (LiMNT) via bond interactions is reported. The prepared porous polymer electrolyte presents a captivating ionic conductivity of 1.82 x 10(-3) S.cm(-1) and lithium ions transference number up to 0.513 at 25 degrees C. In view of the eminent ionic conductivity and efficient migration number of Li+, the three-dimensional porous polymer electrolyte is very conducive to the fast transport and stable deposition of lithium ions, restraining the occurrence and growth rate of lithium dendrites, which improves the cycle performance and rate capability of lithium battery. LiFePO4 vertical bar PPL122 electrolyte vertical bar Li battery delivers a desired cycling performance with a capacity retention of 92% after 1000 cycles at 1 C.

Automated summary

The study introduces a high-powered GPEs modified by polymer polyethylene glycol (PEG) and lithium montmorillonite (LiMNT) via bond interactions, which shows excellent ionic conductivity and high Li+ migration number. The three-dimensional porous polymer electrolyte is conducive to fast transport and stable deposition of lithium ions, restraining the occurrence and growth rate of lithium dendrites. This leads to improved cycle performance and rate capability of lithium battery.