Quinone-Enriched Conjugated Microporous Polymer as an Organic Cathode for Li-Ion Batteries

Abstract

Among various organic cathode materials, CO group-enriched structures have attracted wide attention worldwide. However, small organic molecules have long suffered from dissolving in electrolytes during charge–discharge cycles. π-Conjugated microporous polymers (CMPs) become one solution to address this issue. However, the synthesis strategy for CMPs with rich CO groups and stable backbones remains a challenge. In this study, a novel CMP enriched with CO units was synthesized through a highly efficient Diels–Alder reaction. The as-prepared CMP exhibited a fused carbon backbone and a semiconductive characteristic with a band gap of 1.4 eV. When used as an organic electrode material in LIBs, the insoluble and robust fused structure caused such CMPs to exhibit remarkable cycling stability (a 96.1% capacity retention at 0.2 A g–1 after 200 cycles and a 94.8% capacity retention at 1 A g–1 after 1500 cycles), superior lithium-ion diffusion coefficient (5.30 × 10–11 cm2 s–1), and excellent rate capability (95.8 mAh g–1 at 1 A g–1). This study provided a novel synthetic method for fabricating quinone-enriched fused CMPs, which can be used as LIB cathode materials.

Integrated Covalent Organic Framework/Carbon Nanotube Composite as Li‐Ion Positive Electrode with Ultra‐High Rate Performance

“…Polymeric materials are advantageous because, in addition to tunable insolubility, their molecular structures can be chemically tuned by employing different monomers to improve their performance. [9,10] COFs are a versatile class of crystalline porous solids formed by connecting organic precursors with covalent bonds to generate well-defined 2D or 3D frameworks. [11][12][13] Advantages of COFs include their high structural modularity, which enables functional groups to be introduced into their frameworks in predictable positions, coupled with high porosity and uniform pore sizes.…”

“…Polymeric materials are advantageous because, in addition to tunable insolubility, their molecular structures can be chemically tuned by employing different monomers to improve their performance. [ 9,10 ]…”

Electrochemical Preparation of Poly(N‐anthraquinoyl pyrrole) as High‐Performance Cathode Materials for Organic Lithium‐Ion Batteries

“…[ 49 ] At room temperature, the D Li ranged from 10 −11 to 10 −10 cm 2 s −1 during the lithiation and delithiation processes, which corresponds well with other reported quinone‐enriched polymers. [ 50 ]…”

“…[4][5][6] The electrochemical activities of organic electrode materials mainly depend on their well-designed functional groups (e.g., C═O, C═N, N═N, and S-S). [7] Therefore, many organic materials containing these functional groups were synthesized and applied as electrode materials, such as conductive polymers (e.g., polyacetylene, [8] polyphenyl, [9] polyaniline, [10] and polyimide [11] ), conjugated carbonyl compounds (e.g., quinones [12] and ketones [13] ), and so on. These organic materials presented outstanding electrochemical performances because of their multielectron transfer and structure engineering properties.…”

Catalyst-free nitro-coupling synthesis of azo-linked conjugated microporous polymers with superior aqueous energy storage capability

“…Thus, carbonyl (C=O), imine (C=N), and triphenylamine groups have been incorporated into polymers to function as electrochemical hosts for various cations (e.g., Li + , Na + , Mg 2+ , H + ) [13][14][15]. Building blocks such as quinones [16][17][18][19], phenazine [20,21], and triphenylamine [5,22] are usually employed as conjugated backbones. Furthermore, new redox functionalities are highly demanding to enrich the family of electrochemical CMPs.…”