New Anthraquinone‐Based Conjugated Microporous Polymer Cathode with Ultrahigh Specific Surface Area for High‐Performance Lithium‐Ion Batteries

Abstract

Redox-active conjugated microporous polymers (RCMPs) polymerized by conventional methods are commonly obtained as irregular insoluble solid particles making the electrode processing difficult. In this work, the synthesis of RCMP based on anthraquinone moieties (IEP-11) is developed via a two-step pathway combining miniemulsion and solvothermal techniques that results in polymer nanostructures that are much easier to disperse in solvents facilitating the fabrication of electrodes. Interestingly, this synthetic approach is also found to have an important impact on the inherent morphology of IEP-11 that exhibits a dual porosity combining micro and mesopores with a specific surface area as high as 2200 m 2 g −1 , which is one of the highest values reported for RCMPs. Moreover, the compactness of the electrodes is also improved, the resulting electrodes have triple the density than those obtained with conventional methods. Consequently, when these electrodes are tested as cathodes in Li-ion battery, they deliver high gravimetric capacities (≈100 mAh g −1 ) and extraordinary rate capability keeping 76% of discharge capacity when charged-discharged in only 12 min (@5 C). Moreover, the insoluble and robust conjugated porous structure provides IEP-11-E12 with an unprecedented cycling stability retain ≈90% and ≈60% of its initial capacity after 5000 (@2 C) and 80 000 cycles (@30 C), respectively.

Redox‐Active Porous Organic Polymers for Energy Storage

“…In another hand, the thermodynamically spontaneous redox reactions can be applied for the energy discharging process. 1 In this regard, the redox-active POP 13,14,17,18,[22][23][24] As displayed in Figure 11, the redox-active POP materials have been fabricated on the surface of current collector using the binder and conductive carbon slurry. Usually, the redox-active POP materials have been studied as cathode materials in the Li-half cells.…”

“…The IEP-11-E12 with anthraquinone moieties showed capacities of 69 and 47 mAh/g at the 5C and 30C conditions, as cathode materials for lithium ion batteries, respectively 14 (entries 3 and 4 in Table 1). The charge/discharge potentials were located around 2.35 and 2.15 V (vs Li/Li + ), respectively.…”

“…12 Recently, there have been significant studies on the development of redox-active POPs for energy storage applications. [13][14][15][16][17][18][19][20][21][22][23][24][25] While redox-active metal-organic framework (MOF) and covalent organic framework (COF) have been reviewed, the redox-active (amorphous) POP materials have been relatively less reviewed. 4 In this review paper, we introduce the recent examples of redox-active POP materials for energy storage.…”

Crosslinked Polyimide and Reduced Graphene Oxide Composites as Long Cycle Life Positive Electrode for Lithium‐Ion Cells

“…Recent reports have shown that polymers containing conjugated carbonyl groups show better capacity retention over hundreds of cycles than the corresponding monomers. [26,27] Conductive coatings, and the incorporation of conductive additives, have been used to enhance charge transport in organic electroactive materials, and these strategies have been shown to improve rate capability. [28][29][30] For example, a microporous polyimide covalent-organic framework and carbon nanotube (CNT) composite that was prepared by in situ polymerization was reported to exhibit a near 100 % capacity retention after 8000 cycles, 95 mAh g À 1 at 2000 mA g À 1 (19.2 C), and 104 mAh g À 1 at 200 mA g À 1 (1.9 C).…”

“…Polymerization is also a good strategy to prevent the dissolution of active material during cycling. Recent reports have shown that polymers containing conjugated carbonyl groups show better capacity retention over hundreds of cycles than the corresponding monomers …”