MULTI-ELECTRON PROCESSES FOR LIGHT DRIVEN ELECTRODES AND ELECTROLYTES IN CONVERSION AND STORAGE OF SOLAR ENERGY

Project Information

LIGHT-CAP

Grant agreement ID: 101017821

DOI

10.3030/101017821

Project closed

EC signature date 4 December 2020

Start date 1 January 2021

End date 31 December 2024

Funded under

• EXCELLENT SCIENCE - Future and Emerging Technologies (FET)

Total cost

€ 3 184 393,75

EU contribution

€ 3 184 393,75

Coordinated by

FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA
Italy

Periodic Reporting for period 3 - LIGHT-CAP (MULTI-ELECTRON PROCESSES FOR LIGHT DRIVEN ELECTRODES AND ELECTROLYTES IN CONVERSION AND STORAGE OF SOLAR ENERGY)

Reporting period: 2024-01-01 to 2024-12-31

Summary of the context and overall objectives of the project

The intermittent character of solar energy calls for a stringent need to store it, in order to fully exploit the potential of photovoltaic technologies. The use of separate devices to carry out the two distinct processes, namely solar panels and big batteries, both characterized by high costs of installation and maintenance, as well as large sizes and weight, is nowadays the only available solution on the market. With the LIGHT-CAP project, we aim at tackling this current limitation in the renewable energy field by developing a hybrid technology that combines light energy conversion and storage into one single compact unit with low volume and weight, based on environmentally friendly and Earth abundant materials. In this way, we will stimulate the genesis of a novel Europe-based innovation eco-system around this new technological paradigm with a direct impact on portable and mobile electronics, simultaneously setting the basis for its future exploitation in large area systems too. The achievement of the LIGHT-CAP’ objectives will contribute to a future sustainable and zero-emission energy landscape in Europe, which is the urgent goal set by the European Commission with the European Green Deal.
Therefore, the overall objectives of LIGHT-CAP are properly those of providing new solutions for the solar-powered, low-cost, lightweight and compact generation and storage of clean energy. The disruptive technology targeted by LIGHT-CAP aims at a paradigm shift in renewable energy conversion and storage by exploring and exploiting the radically new principles of direct light energy absorption and accumulation in an emergent materials combination, originating from the coupling of zero-dimensional (0D) nanocrystal photo-capacitor (NCPCs) and graphene quantum dots (GQDs). 0D NCPCs, such as the transparent conducting oxides display remarkable charge-storage capability of multiple electrons per nanostructural unit as delocalized charges after light absorption. The main innovation of LIGHT-CAP resides indeed in the use of 0D NCPCs together with specifically designed multiple hole collectors, such as GQDs and other 2D materials. A key-advantage of employing GQDs among other nanomaterials consists in the possibility to apply bottom-up chemical synthesis routes to tailor them into atomically precise structures addressing variations in optoelectronic properties. GQDs and 0D NCPCs were combined and their light-induced interaction studied, highlighting the possibility of charge transfer between the two subunits, of importance to their use in liquid-liquid interfaces.The photoactive compartment consists of a 0D NCPC-based anolyte that store negative charges. The GQD dispersion acting as catholyte accepts the positive charges. This serves as first demonstrators for the light driven charge separation in solution. In solid state GQDs were deposited over optimized 0D NCPC electrodes and the systems were characterized with and without the excitation with light revealing charge transfer effects.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The consortium performed a literature review to extract novel doped metal oxides that can serve as 0D NCPCs based on non-critical raw materials. We then synthesized a set of metal oxide nanomaterials, such as ITO and Cu2O, as photo-active materials for the light-driven electrodes. We made use of solution processing deposition techniques in order to optimize respectively large area fabrication and micro-devices. We have successfully synthesized HBC-1 bearing bulky functional groups exhibiting good solubility in common organic solvents. We then studied the densification of nanoparticle inks with HBC-1 and the electronic characterization of their hybrid interaction with 0D NCPCs. Such interactions benefit the photo-doping phenomenon supporting the stability of photo-generated charges thanks to the hole-delocalization effect from the GQDs. Further we investigated other possible candidates for capacitor-like systems, in combination with 0D nanocrystal photocapacitors, based on 2D organic and inorganic materials such as metal-oxide frameworks and MXenes. Within LIGHT-CAP consortium we performed different tests in order to analyze the photoelectrochemical behavior, by means of photo-electrochemical analytical methods (CV, Impedance, GCD, OCP, photocurrent, chronoamperometry) as well as ultrafast spectroscopy and electrical characterizations, for the actual energy conversion and storage applications. In particular, we explored the possible use of the abovementioned materials in both in liquid phase and solid state. As for the first case we studied photo-generated charge extraction/transfer between OD and 2D materials as well as with various common redox active electrolytes. We then investigated the photo-electrodes/electrolyte (solid/liquid) and solid/solid, 0D/2D, interactions and the effect of light on the performance of the photoelectrodes. As proof of concept we analysed a complete solar flow battery system consisting of two reactors, with two-electrode configuration in series, operating under flow conditions. Moreover a light-driven capacitor was presented based on 0D NCPCs.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The LIGHT-CAP project seeks to change drastically the state-of-the-art of solar energy conversion and related accumulation, which today is still based mostly on expensive silicon solar panels and cumbersome batteries kept separated in two distinct devices, each one requiring its own maintenance. LIGHT-CAP will introduce new nanotechnology-enabled architectures combining the two functionalities in one single versatile device, in which the main components are constituted of eco-friendly and earth-abundant materials, thus not suffering from future possible risks of supply. The project tackles fundamental challenges like making possible a more efficient solar energy harvesting, conversion, storage, and controlled on-demand release for the fabrication of both portable and static technologies, potentially producing a considerable impact in the field of portable and mobile electronics that will drive the paradigm change towards a future sustainable and zero-emission energy landscape in Europe.
The special combination of nanomaterials such as graphene and its derivatives, together with metal oxide in nanoparticle-form (Indium, Zing, Iron, Tin), already in use within the electronic components of devices currently in use, will allow to realize active interfaces in solid and/or liquid form in which sunlight promotes the occurrence of multiple and reversible transfers of electrical charges, offering large room for improvement in charge storage capacity in comparison with classical batteries and supercaps. In addition, these species present interesting long-term stability and cyclability profiles, which will make them very competitive substitutes for active components in current energy storage technologies.
The ambitious LIGHT-CAP roadmap will allow creating the basis for the ignition of new production lines and products able to promote an innovative and sustainable vision on the energy market that will dominate the future economic scenario in Europe, aiming at the continuous decrease of the carbon footprint. Within this framework, the development of new products and transfer of technology to new markets will be incubated and made available for European R&D, allowing the building of skilled occupations, which can leverage the efforts of the European Commission to attain a globally competitive position.

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