Periodic Reporting for period 2 - MUSIC (Materials for Sustainable Sodium-Ion Capacitors)
Periodo di rendicontazione: 2024-07-01 al 2025-12-31
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.
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.