Octahydroxytetraazapentacenedione: New Organic Electrode Material for Fast and Stable Potassium Batteries

We report the synthesis and electrochemical characterization of octahydroxytetraazapentacenedione (OHTAPQ). The potassium batteries using OHTAPQ as electrode material delivered the specific capacity of 190 mAh g−1 at the current density of 0.6 A g−1. The use of the concentrated (2.2 M KPF6) diglyme-based electrolyte suppressed significantly the capacity fading of the potassium half-cells with OHTAPQ electrodes thus enabling their stable operation for 1200 charge-discharge cycles. Furthermore, OHTAPQ delivered the specific discharge capacity of 82–103 mAh g−1 at high current densities of 9–21 A g−1, which leads to high power densities approaching 41000 W kg−1. Thus, we demonstrate that the rationally designed organic electrode material enables high-capacity and high-power potassium batteries, which can be considered as a more environment-friendly and scalable alternative to the mainstream lithium-ion battery technology. © 2021 Elsevier B.V.This work was supported by the Russian Ministry of Science and Education (project 0089-2019-0010/AAAA-A19-119071190044-3 ). The XPS measurements were supported by the Ministry of Science and Higher Education of the Russian Federation (FEUZ-2020-0060), and Theme “Electron”, AAAA-A18-118020190098-5 at IPT UrFU and IMP UB RAS . The solid-state NMR spectroscopy experiments were performed at the Center of the Shared Facilities of IPCP RAS and Research Resource Center of the Scientific Center “Chernogolovka” of RAS. PAT acknowledges the support from EU’s Horizon 2020 ERA-Chair project ExCEED, grant agreement No 952008

A Review on Fullerene Derivatives with Reduced Electron Affinity as Acceptor Materials for Organic Solar Cells

Organic solar cells (OSCs) represent a promising emerging photovoltaic technology offering such benefits as light weight, mechanical flexibility, semitransparency, environmental friendliness and aesthetic design of solar panels. Furthermore, organic solar cells can be produced using scalable and high-throughput solution-based printing and coating technologies, which are expected to lead to very low product costs. Fullerene derivatives have been used as acceptor materials in virtually all efficient organic solar cells for more than two decades, following the demonstration of the first proof-of-concept devices in the middle of 1990s. Still, the power conversion efficiencies of fullerene-based organic solar cells became stuck at around 12% due to the suboptimal optoelectronic properties of conventional fullerene acceptors. Therefore, the latest efficiency records (>18%) for organic solar cells were set using different types of non-fullerene acceptor (NFA) materials with tailorable properties. However, NFA materials appeared to be very sensitive to light, thus impairing the operational stability of OSCs. On the contrary, there is growing evidence that rationally designed fullerene-based acceptors enhance the photostability of conjugated polymers and also NFAs, when used in ternary blends. Hence, a renaissance of fullerene-based materials is currently expected in the context of their use in multicomponent organic solar cells (e.g., as stabilizers) and also lead halide perovskite solar cells, where they play an important role of electron transport materials. The success in both of these applications requires the tunability of optoelectronic characteristics of fullerene derivatives. In particular, electron affinity of the fullerene cage has to be reduced in many cases to match the energy levels of other absorber material(s). Herein, we present a systematic review of different strategies implemented to reduce the acceptor strength of the fullerene derivatives and the results of their performance evaluation in OSCs with model conjugated polymers. Particular attention is paid to correlations between the chemical structure of organic addends and their influence on the electronic properties of the fullerene core. We believe this review would be valuable to researchers working on the rational design of new fullerene-based materials with tailored properties for photovoltaic and other electronic applications

Rational Design of Fullerene Derivatives for Improved Stability of p-i-n Perovskite Solar Cells

Perovskite solar cells (PSCs) with p-i-n architecture attracted particular attention from the research community due to their simple and scalable fabrication at low temperatures. However, the operational stability of p-i-n PSCs has to be improved, which requires the development of advanced charge transport interlayers. Fullerene derivatives such as phenyl-C61-butyric acid methyl ester (PC61BM) are commonly used as electron transport layer (ETL) materials in PSCs, though they strongly compromise the device stability. Indeed, it has been shown that PC61BM films actively absorb volatile products resulting from photodegradation of lead halide perovskites and transport them towards top metal electrode. Thus, there is an urgent need for development of new fullerene-based electron transport materials with improved properties, in particular the ability to heal defects on the perovskite films surface and block the diffusion of volatile perovskite photodegradation products. To address this challenge, a systematic variation of organic addends structure should be performed in order to tailor the properties of fullerene derivatives. Herein, we rationally designed a series of fullerene derivatives with different side chains and explored their performance as ETL materials in perovskite solar cells. It has been shown that among all studied compounds, a methanofullerene with thiophene pendant group enables both high efficiency and improved device operational stability. The obtained results suggest that further engineering of fullerene-based materials could pave a way for the development of advanced ETL materials enabling long lifetimes of p-i-n perovskite solar cells

Environmentally sustainable organic field effect transistors

Environmentally sustainable systems for the design, production, and handling of electronic devices should be developed to solve the dramatic increase in electronic waste. Sustainability in plastic electronics may be the production of electronic devices from natural materials, or materials found in common commodity products accepted by society. Thereby biodegradable, biocompatible, bioresorbable, or even metabolizable electronics may become reality. Transistors with an operational voltage as low as 6 V, a source drain current of up to 0.5 μA and an on–off ratio up to four orders of magnitude, with saturated field effect mobilities in the range of 1.5 × 10−4 to 2 × 10−2 cm2/V s, have been fabricated with such materials. Our work comprises steps towards environmentally safe devices in low-cost, large volume, disposable or throwaway electronic applications, such as in food packaging, plastic bags, and disposable dishware. In addition, there is significant potential to use such electronic items in biomedical implants. As such, organic materials offer a unique opportunity to guide electronics industry towards an environmentally safe direction

Self-Organization of Fullerene Derivatives in Solutions and Biological Cells Studied by Pulsed Field Gradient NMR

Fullerene derivatives are of great interest in various fields of science and technology. Fullerene derivatives are known to have pronounced anticancer and antiviral activity. They have antibacterial properties. Their properties are largely determined by association processes. Understanding the nature and properties of associates in solvents of various types will make it possible to make significant progress in understanding the mechanisms of aggregation of molecules of fullerene derivatives in solutions. Thus, this work, aimed at studying the size and stability of associates, is relevant and promising for further research. The NMR method in a pulsed field gradient was used, which makes it possible to directly study the translational mobility of molecules. The sizes of individual molecules and associates were calculated based on the Stokes–Einstein model. The lifetime of associates was also estimated. The interaction of water-soluble C60 fullerene derivatives with erythrocytes was also evaluated. The values of self-diffusion coefficients and the lifetime of molecules of their compounds in cell membranes are obtained. It is concluded that the molecules of fullerene derivatives are fixed on the cell surface, and their forward movement is controlled by lateral diffusion

Highly selective reactions of C(60)Cl(6) with thiols for the synthesis of functionalized [60]fullerene derivatives

Chlorofullerene C(60)Cl(6) undergoes highly selective reactions with thiols forming compounds C(60)[SR](5)H with high yields. These reactions open up straightforward synthetic routes to many functionalized fullerene derivatives, e.g. water-soluble compounds showing interesting biological activities.status: publishe