Asbestos-functionalized solid polymer electrolyte for uniform Li deposition in lithium metal batteries

Abstract

Lithium metal anode possesses promising prospects for the new generation of high-capacity lithium batteries. However, the hazardous lithium dendrite of Li metal leads to inferior cycling stability, which blocks their commercial applications. In this work, an asbestos (ASB) functionalized solid polymer electrolyte (SPE) is presented to facilitate even lithium deposition. The density functional theory calculations confirm that lithium ions (Li+) tend to adsorb on ASB rather than poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) during the deposition process, resulting in the optimization of Li+ distribution in the SPE and the uniform deposition of Li+, which suppresses lithium dendrite growth. The ionic conductivity and Li+ transference number (tLi+) of the ASB functionalized SPE at 30 ℃ are enhanced to 0.77 mS cm−1 and 0.63, respectively. After 300 cycles at 30 ℃, LiFePO4 battery with the ASB functionalized SPE reveals a discharge capacity of 133 mAh g−1 at 1 C. Besides, the even and smooth surface morphology of Li metal employed the ASB functionalized SPE after cycling demonstrates that the dendrite can be successfully inhibited. The ASB functionalized SPE proposes a prospective strategy for restraining lithium dendrite.