High‐Performance Lithium‐Ion Capacitors Based on Porosity‐Regulated Zirconium Metal−Organic Frameworks

Abstract

Comprised of a battery anode and a supercapacitor cathode, hybrid lithiumion capacitors (HLICs) are found to be an effective solution to realize both high power density and high energy density at the same time. Organic-inorganic hybrid materials with well-organized framework guided by the reticular chemistry are one of the promising anode materials for HLICs because of rich active sites and ordered porosity. Herein, metal−organic framework consisting of Zr 4+ metal ions and tetrathiafulvalene-based ligands (Zr-MOF) is proposed as the pseudocapacitive anode of HLICs. The Zr-MOF possesses high stability, high crystallinity, and multiple meso-microporous channels favorable for ion transport. The as-prepared Zr-MOF||activated carbon HLICs present high energy density (122.5 Wh kg −1 ), high power density (12.5 kW kg −1 ), and stable cycling performance (86% capacity retention after 1000 cycles at 2000 mA g −1 ) within the operating voltage range of 1.0-4.0 V. The results expand the direct application of MOF for bridging the performance gap between batteries and supercapacitors.

Cluster‐Bridging‐Coordinated Bimetallic Metal−Organic Framework as High‐Performance Anode Material for Lithium‐Ion Storage

“…This outstanding rate performance and cycling stability of the Co 4 ‐Ir MOF are competitive among previously reported pristine MOF anodes (Table S3, Supporting Information). [ 22–31 ] The high surface area of the nanostructural materials results in unstable solid‐electrolyte interfaces (SEI) and successive consumption of electrolyte, which is the potential reason for the capacity decay of MOFs. We suggest that the cycling stability of MOFs could be further improved by tuning their sizes, microstructures, and compositions, as well as adding proper electrolyte additives to enhance the stability of SEI film and reduce the electrolyte consumption.…”

“…The outstanding energy density, power density, and lifespan of the Co 4 ‐Ir MOF||AC HLIC are competitive among the previously reported HLICs with MOF‐based anode materials (Figure 6c). [ 29,30,58–60 ] The cycling stability of HLICs was evaluated by long‐term cycling experiments at 4000 mA g −1 , showing a high capacity retention of 73.6% after 3000 cycles.…”

“…[ 21 ] Recently, the probability of utilizing pristine MOFs as active materials in the anodes of LIBs has been investigated. [ 22–31 ] To date, two main types of lithiation/delithiation mechanisms in pristine MOF anode materials have been proposed: 1) “metal‐dominated” mechanism involving the conversion reaction of metal ions, such as Mn[Fe(CN) 6 ] 0.6667 ·nH 2 O, [ 23 ] Mn‐LCP, [ 26 ] and NNU‐11 [ 27 ] ; and 2) “organic‐dominated” mechanism with Li + intercalation/deintercalation, such as 2,6‐naph(COOLi) 2 , [ 22 ] Cu‐BTC, [ 24 ] and Co 2 (OH) 2 BDC. [ 25 ] The MOF anode materials with a “metal‐dominated” mechanism exhibit a constant voltage plateau with one or more electrons stored per unit, but they deliver limited specific capacities in view of their large molecular masses.…”

Room‐Temperature Solvent‐Free Synthesis of Three‐Dimensional Flower‐Like α‐MnO2 Microspheres for Supercapacitor Application

“…The construction of microstructures in three‐dimensional space can occur via the use of templates or altering the agent in solution that controls the structure. Meanwhile, the materials prepared by liquid phase method generally have advantages in crystallinity and homogeneity [18–22] . In this way, functional materials with enhanced performance can be obtained through a strategy that permits a reasonable level of control [23] .…”

Novel Lithium-Ion Capacitor Based on a NiO-rGO Composite

“…To maximize their electrochemical performance, lithium-ion capacitors (LICs) have been widely studied. The main factor affecting the performance of LICs is the mismatch of reaction kinetics between the two electrodes; the parameter with the greatest influence in this regard is the electrode material [14][15][16][17][18]. Therefore, the identification of electrode materials with a suitable specific capacity, remarkable rate performance, and excellent stability has become a key challenge.…”