Project Title: Boron Repositories fabricated Additively for energy Storage Aplications 

Acronym: BRASA (PID2024-157151OB-I00)

Funding Entity: Ministerio de Ciencia, Innovación y Unicersidades  (MICIU) – Agencia Estatal de Investigación (AEI)

Participating Entities:  University of Extremadura

Duration: 01/09/2025 – 31/08/2028

Budget: 162.500,00  €

Principal Investigator (PI): Pedro Miranda

Number of researchers: 3

Abstract:

BRASA project will develop structural materials suitable for the implementation of ultra high-temperature, high energy density (over 1.7 MWh/m3, and 500 Wh/Kg are expected) thermal energy reservoirs where energy is stored in the form of latent heat of boron and its alloys. In particular, it will demonstrate that it is possible to additively manufacture (additive manufacturing, AM) durable refractory vessels for boron-based phase change materials (PCMs) from ultra-high temperature ceramics (UHTCs). With the help of additive manufacturing, BRASA project seeks to develop interpenetrating phase composites (IPCs) between the vessel and PCM materials that, thanks to the high thermal conductivities of ultra-high temperature ceramics acting as vessel materials and the large interfacial area of the IPCs, will act also as efficient heat exchangers for fast charge/discharge rates. This strategy will provide an all-in-one solution for the fabrication of efficient high temperature thermal energy storage systems (HTTES). Such HTTES could safely and efficiently store renewable energy, directly from concentrated solar or from renewable electricity surplus using efficient power-to-heat (P2H) conversion solutions (like direct joule heating, which will be evaluated in the context of the project). The stored thermal energy could be used to provide clean heat at ultra-high temperatures that are relevant to heavy industries (e.g. steel, cement, glass, ceramics, etc.) that are otherwise difficult to decarbonize or be used to power zero-emissions propulsion systems in aviation (e.g. in combination with micro gas turbines) and aerospace (e.g. solar-thermal propulsion). Heat-to-power (H2P) conversion is also greatly facilitated since the high temperature of these thermal storage solutions greatly increases the efficiency of existing alternatives, both those based on micro-turbines and, especially, in the case of thermophotovoltaic solutions. Efficient P2H2P solutions will enable the use of the HTTES energy reservoirs for electrical grid support with green energy from renewable power sources.

In the context of this project the most appropriate candidate materials for the fabrication of these HTTES will be selected and their thermo-mechanical performance and thermo-chemical degradation will be evaluated experimentally. Moreover, the manufacturing process for the fabrication of UHTC vessels and boron/UHTC interpenetrating phase composites will be optimized, aiming at developing a cost-effective and green processing route. The
reservoirs 3D architecture will be optimized as well with the aid of finite element modelling to maximize heat exchange and the thermomechanical performance and long term durability of the HTTES.
All these solutions will become key enabling technologies (KET) for the complete decarbonization of heat, electricity and transport sectors, with the ultimate goal of contributing to the transition to a climate neutral economy by 2030.