Bioinspired design of vascularized glassy metal-organic frameworks electrolyte for quasi-solid-state sodium batteries

Abstract

Quasi-solid-state electrolytes (QSSEs) are regarded as the most promising alternative for next-generation battery technology due to the compatibility of assemble process and high safety. However, the rational design of solid hosts to ensure the high-efficiency utilization of tiny liquid electrolytes and the deep understanding of ion transport mechanisms at heterogeneous structures are still challenging. Herein, inspired by the ion transport in biological blood vessels, we propose a nitrogen vacancy modified glassy metal-organic framework (MOF) as Na-ion QSSEs host, which shows multilevel ions transport channels, isotropy property, and no grain boundaries. The vascularized glassy MOF enables the reasonable distribution of a small amount of solvent (14 wt.% (solvent as a percentage of QSSE by mass)) in both macro and microenvironments with specific functions, boosting the fast Na-ion transport (1.18 × 10⁻⁴ S cm^–1, 30 °C) and Na-ion transfer number (0.92), and homogeneous Na-ion nucleation/propagation even at -50 °C. Meanwhile, the quasi-solid-state Na||Na₃V₂(PO₄)₃/C cell demonstrates excellent rate capability and long cycling stability (0.0288 % capacity decay per cycle after 500 cycles). The bioinspired design of glassy MOF will shed light on new avenues for the development of energy storage and conversion.