A Single-Ion Conducting UiO-66 Metal–Organic Framework Electrolyte for All-Solid-State Lithium Batteries

Abstract

A metal−organic framework (MOF) single lithium-ion conductor has been synthesized by covalently immobilizing anions to the skeleton of MOF structures. The functionalized UiO-66 MOF exhibits an electrochemical stability window of 5.2 V versus Li|Li + and ionic conductivity of 6.0 × 10 −5 , 7.9 × 10 −5 , and 1.1 × 10 −4 S/cm at 25, 60, and 90 °C, respectively. It displays single-ion conducting behavior with a high Li-ion transference number of 0.90 at 25 °C in the absence of any plasticizer. After ethylene carbonate and propylene carbonate are incorporated into the MOF structure, its ionic conductivity reaches 7.8 × 10 −4 S/cm at room temperature. The MOF electrolyte has been evaluated with all-solid-state Li|MOF|LiFePO 4 batteries at room temperature, showing excellent rate capacity and cycling stability.

Stabilization of Li0.33La0.55TiO3 Solid Electrolyte Interphase Layer and Enhancement of Cycling Performance of LiNi0.5Co0.3Mn0.2O2 Battery Cathode with Buffer Layer

“…Over the past several decades, the successful application of lithium-ion batteries has revolutionized personal electronic devices and significantly changed our lifestyle [ 1 , 2 ]. All-solid-state lithium batteries (ASSBs) are promising battery systems for electric vehicles and smart devices owing to their safety, energy density, packaging, and operating temperature range compared with traditional liquid electrolytics [ 3 , 4 , 5 ]. However, the low ionic conductivity of solid electrolytes hinders their commercial applications [ 6 , 7 , 8 ].…”

Na-ion Hybrid Energy Storage Devices Based on Nanoengineered Electrodes

“…Hence, Na-ion transference number (tNa+), proving the information of Na-ion mobility and diffusivity is a key parameter for QSS electrolytes. 40,260 It can be found that (Figure 6.13a, b) the tNa+ of the Celgard, PVDF-HFP, and hybrid QSS electrolytes are 0.18, 0.37, and 0.55, respectively. Higher tNa+ of the hybrid QSS electrolytes increasing with an increase of UiO-66 loading suggests the ability of activated UiO-66 that facilitates the Na-ion transport.…”

“…The activation energy (Ea) of the Na-ion migration in the QSS electrolytes was calculated using the slopes of ln (σ) vs. T -1 (Table 6 indicate a lower energy barrier for Na-ion migration, which is essential for the fabrication of polymer-based QSS electrolytes. 260 It has been established that the liquid electrolyte entrapped in the pores of the polymer matrix will further swell the amorphous domains to form a gel state. 276 Thus, Na-ions can be transferred in porous polymer-based QSS electrolytes: (a) through the liquid solution absorbed in pores; (b) through swelled amorphous domains; and (c) along molecular chains in the polymer matrix.…”

“…However, to our knowledge, there are very few or no works reported to exploit these unique properties of PVDF-HFP and MOFs especially for Na-ion based energy storage systems.In this section, a high-performance quasi-solid-state Na-ion hybrid capacitor enabled by a multifunctional UiO-66/PVDF-HFP hybrid separator is presented. Activated UiO-66 is selected as active fillers into the PVDF-HFP based on the following aspects 247,259,260. (i) Their…”

“…The corresponding resistances can be obtained from the Nyquist plots, where the AC responses present an inclined straight-line (the ion-blocking electrode behavior). The interception on the real axes, Z′RE, provides the bulk ionic resistance of the QSS electrolyte 250,260. The ionic-conductivity values at 25 ℃ calculated by equation 3 are listed in Table6.2.…”