Harnessing enhanced lithium-ion storage in self-assembled organic nanowires for batteries and metal-ion supercapacitors†

Abstract

Organic materials have emerged as highly efficient electrodes for electrochemical energy storage, offering sustainable solutions independent from non-renewable resources. In this study, we showcase that mesoscale engineering can dramatically transform the electrochemical features of a molecular organic carboxylic anode. Through a sustainable, energy-efficient and environmentally benign self-assembly strategy, we developed a network of organic nanowires formed during water evaporation directly on the copper current collector, circumventing the need for harmful solvents, typically employed in such processes. The organic nanowire anode delivers high capacity and rate, reaching 1888 mA h g⁻¹ at 0.1 A g⁻¹ and maintaining 508 mA h g⁻¹ at a specific current of 10 A g⁻¹. Moreover, it exhibits superior thermal management during lithiation in comparison to graphite and other organic anodes. Comprehensive electrochemical evaluations and theoretical calculations reveal rapid charge transport mechanisms, with lithium diffusivity rates reaching 5 × 10⁻⁹ cm² s⁻¹, facilitating efficient and rapid interactions with 24 lithium atoms per molecule. Integrated as the negative electrode in a lithium-ion capacitor, paired with a commercially available porous carbon, the cell delivers a specific energy of 156 W h kg⁻¹ at a specific power of 0.34 kW kg⁻¹ and 60.2 W h kg⁻¹ at 19.4 kW kg⁻¹, establishing a benchmark among state-of-the-art systems in the field. These results underscore the critical role of supramolecular organization for optimizing the performance of organic electrode materials for practical and sustainable energy storage technologies.