Polynitrosoarene Radical as an Efficient Cathode Material for Lithium-Ion Batteries

Abstract

Organic radical batteries (ORBs) with radical-branched polymers as cathode materials represent a valuable alternative to meet the continuously increasing demand on energy storage. However, the low theoretical capacities of current radical-contained compounds strongly hamper their practical applications. To address this issue, a chemically robust polynitrosoarene (tris(4-nitrosophenyl)amine) with a pronounced radical property is rationally designed as an efficient cathode for ORBs. Its unique multi-nitroso structure displays remarkably reversible charge/discharge capability and a superior capacity up to 300 mA h g–1 (93% theoretical capacity) after 100 cycles at 100 mA g–1 within a broad potential window of 1.3–4.3 V (vs Li+/Li). Moreover, the ultra-long cycle life is also achieved at 1000 mA g–1 with 85% preservation of the capacity after 1000 cycles, making it the best-reported organic radical cathode material for lithium-ion batteries.

Construction of Crystalline Nitrone-Linked Covalent Organic Frameworks Via Kröhnke Oxidation

“…Two novel polynitroso monomers were first prepared by nitrosodesilylation of corresponding trimethylsilyl-substituted precursors with BF 4 NO in quantitative yields (Scheme S1). 51 The preparation of nitrone-based COF was initially conducted between 1,3,5-tris (4-nitrosophenyl) benzene (TPB-3NO) and BPS under the same conditions as in the model reaction. Unfortunately, only the amorphous polymer was obtained.…”

“…At present, the approaches to multinitroso structures are rare and generally distinct from those of mononitroso compounds due to their intrinsically low stability and elusive persistence, 50 which significantly retards their application in COFs. Very recently, we reported a facile and general method toward robust ploynitroso compounds by nitrosating the corresponding trimethylsilyl-substituted precursors with BF 4 NO in quantitative yields, 51 which enables the usage of nitroso-based building units in synthesis of COFs. For the activated arylmethylene monomers, a benzylic bipyridinium salt was judiciously designed and employed.…”

Lithium Storage Mechanism: A Review of Perylene Diimide N-Substituted with a 1,2,4-Triazol-3-yl Ring for Organic Cathode Materials

“…Organic cathodes with high cycle performance in previous reports usually were a large single molecule with a high molecular weight and a dense redox-active functional group structure such as a carbonyl group (CO). Recently, not a carbonyl group but various redox-active functional groups, such as a nitro group (−NO 2 ), a dicyanomethyl group (−CH­(CN) 2 ), aromatic N-heterocycles, and radical species, have been extensively studied to improve the working voltage, specific capacity, and cycle stability, leading a new paradigm for the organic cathode. − Kang et al reported tris (4-nitrosophenyl) amine (TPA-3NO) as an organic radical cathode for LIBs, which showed excellent performances with a capacity of 300 mAh g –1 over 100 cycles in a wide potential range of 1.3–4.3 V vs Li/Li + . Its three nitroso groups (−NO) and the nitrogen atom of triphenyl amine revealed behaviors of n-type (accepting the electrons during the discharge process) and p-type (donating the electrons during the charge process), respectively.…”

“…11−14 Kang et al reported tris (4-nitrosophenyl) amine (TPA-3NO) as an organic radical cathode for LIBs, which showed excellent performances with a capacity of 300 mAh g −1 over 100 cycles in a wide potential range of 1.3−4.3 V vs Li/Li + . 15 Its three nitroso groups (−N�O) and the nitrogen atom of triphenyl amine revealed behaviors of n-type (accepting the electrons during the discharge process) and p-type (donating the electrons during the charge process), respectively. As such, the key to the development of organic cathodes is to search for redox-active functional groups with high energy density by controlling their electronic and chemical structures.…”

Reversible and high-contrast thermal conductivity switching in a flexible covalent organic framework possessing negative Poisson's ratio

“…With high porosities, extended periodicities, and large surface areas, COFs have emerged as new frontier materials that combine unique physical properties arising mostly from their highly modular architectures. 15–22 This combination of superlative physical properties positions COFs as attractive candidates for a plethora of applications over conventional polymers or even their metal organic framework (MOF) cousins. 15 For instance, COFs (when compared to MOFs) have shown a better promise for several thermal management applications, 23 owing to their relatively higher thermal conductivities originating from their extended crystalline frameworks comprising of strongly bonded light atoms ( e.g.…”