Materials for Sustainable Sodium-Ion Capacitors

Project Information

MUSIC

Grant agreement ID: 101092080

DOI

10.3030/101092080

EC signature date 18 November 2022

Start date 1 January 2023

End date 31 December 2026

Funded under

• Digital, Industry and Space

Total cost

€ 6 297 579,00

EU contribution

€ 6 297 578,75

Coordinated by

CENTRO DE INVESTIGACION COOPERATIVA DE ENERGIAS ALTERNATIVAS FUNDACION, CIC ENERGIGUNE FUNDAZIOA
Spain

Periodic Reporting for period 2 - MUSIC (Materials for Sustainable Sodium-Ion Capacitors)

Reporting period: 2024-07-01 to 2025-12-31

Summary of the context and overall objectives of the project

In the face of the global climate crisis and the urgent need to limit global warming below 2ºC by 2100, Europe aims to become a climate-neutral, circular, and competitive, zero polluting economy by 2050. Electrifying the key sectors transport, power, and industry will help to reduce greenhouse gas (GHG) emissions that are mainly responsible for global warming. The energy generation by renewables and their electrochemical storage will be key for such a transformation. Europe needs to take the lead in strategic value chains while reinforcing its independence and resilience with a secure supply in raw materials. Materials for sUstainable Sodium Ion Capacitors (MUSIC) develops a new supercapacitor (SIC) technology that reaches energy densities comparable to that of power batteries, but recharges within a few seconds and offers long cycle life with minimum efficiency loss over time for applications in renewables, industry and transport. Developing a technology that is sustainable by design and avoids the use of critical raw materials will reduce Europe’s dependencies along the raw materials value chain.

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

WP2 defined the requirements, specifications, and testing conditions, considering functionality and performance (energy & power profiles, cycle life expectancy), operating environment (temperature and humidity), and safety. It also outlined requirements for future SIC designs, a testing procedure, and a plan to validate these materials under realistic conditions, ensuring effectiveness and safety in sectors like railways and renewable energy.
WP3 focused on the synthesis and characterization of materials for SICs. After starting with Gen0 materials, the past two years have focused on improving sustainability and performance. Soft and hard carbons derived from biowaste have been synthesized, and the performance of new materials is nearing target goals. Notably, recycled aeronautical carbon fibers have shown good electrochemical performance, while new binder formulations and electrolyte configurations have been developed.
WP4 investigates the charge storage mechanism in SIC active materials using advanced characterization. The equipment has been implemented and tested on model materials and first-generation materials. This WP has shown the complementarity of different techniques for studying the electrode/electrolyte interface, sodium intercalation, and the implementation of new materials like recycled carbon fibers. The focus was on the binder's effect on the SEI of the negative electrode and the role of sacrificial salts in the positive electrode.
In WP5, significant progress has been made in electrode and pouch cell processing, despite technical and logistical challenges. Efforts were focused on developing both positive and negative electrodes, alongside ongoing work on aging and degradation mechanisms and initial dry processing analysis.
WP6 aimed to manufacture MUSIC SIC cells on a pilot line for large-scale production. RP2 laid the foundation for reproducible manufacturing of electrodes, particularly through progress in mixing and coating processes for the positive electrode, compatible with mature manufacturing technology at BYD.
WP7 developed smart SIC modules, integrating sensors and i-SMS. Commercial LIC pouch cells were screened, and the first 12V module using LIC technology was created, featuring an innovative SMS and estimation algorithms. However, delays in WP6 regarding SIC cell delivery have delayed electrical characterization and the adaptation of i-SMS.
WP8 established a methodological and data foundation for the sustainability assessment of SIC technologies. LCA of the multilayer cell highlighted key material hotspots like NaPF₆, NMP, and PC, with pilot-scale results confirming the importance of electrolyte choices, binder systems, and sacrificial salt synthesis on both environmental impacts and costs. Findings suggest that alternative materials and processes, such as water-based binders and efficient sacrificial salts, can improve the environmental and economic performance of SICs.

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)

MUSIC aims to develop supercapacitors with energy densities comparable to batteries, using environmentally friendly electrolytes. These supercapacitors recharge quickly, maintain performance over time, and have a longer lifespan. The advanced materials used will be free of Critical Raw Materials (CRM), instead relying on non-toxic, eco-friendly alternatives like carbon-based electrodes, green binders, and sustainable electrolytes. Materials like hard carbons and activated carbon are being developed for high capacity and high-rate performance, using natural resources, which makes them environmentally friendly. However, further work is needed to optimize their energy-to-power output.
MUSIC is also working on sustainable, aqueous-based slurry processing for both the positive and negative electrodes, eliminating toxic solvents like NMP and fluorinated compounds (e.g. PVDF) in favor of water and natural binders like CMC. This reduces energy consumption in electrode fabrication and enables easier recycling of materials. These developments contribute to climate change mitigation efforts.
Additionally, MUSIC will advance smart supercapacitor management systems (i-SMS) by integrating sensors into eco-designed SIC modules. During RP2, a 12V LIC module was developed with a focus on safety, performance, and recyclability. The i-SMS includes cell-level sensors for voltage, temperature, and impedance, as well as balancing systems and algorithms for state of health (SOH), state of charge (SOC), and state of power (SOP).
Life Cycle Assessments (LCA) and Life Cycle Costing (LCC) have been carried out to identify environmental and economic hotspots, optimizing material and process sustainability. This work directly contributes to circular economy efforts by assessing the sustainability of EDLCs and sodium-ion capacitors, reducing the environmental impact of energy storage in Europe’s mobility and energy sectors.
MUSIC follows a phased market entry strategy, initially targeting niche sectors where performance, safety, or regulatory drivers take precedence over cost, such as railway braking energy recovery, grid-connected services, industrial power buffering, and electric mobility fleets. Long-term applications like IoT, medical devices, and hybrid fuel-cell systems are also under consideration.
Ultimately, MUSIC will establish new industrial value chains with energy storage products tailored to end-user needs, with all materials produced in Europe to reduce dependence on imports.