On the overall, the results of the AMAPOLA have shown that the combination of Aluminium and Sulfur as a potential battery technology is feasible. Some promising electrochemical performance was obtained with aluminium-sulfur batteries made with acetamidine-based electrolytes.
However, the technology would require of more development to overcome the main challenges found during the project implementation, explained along the report and summarised below:
- The deep eutectic solvents (DES) developed in the project are not fully compatible with the cathode due to their high Lewis acidity. This most probably drives to chemical decomposition of the cathodic particles/electrolyte, that ultimately causes capacity depletion.
- The binder used in the cathode formulations plays a role, although the extent of its influence and whether or not it can be taken advantaged of in order to improve the cathode performance has remained beyond the reach of the project.
- The aluminium anode requires of eliminating the passive native oxide layer. The presence of the passivation layer results in non-uniform current distribution which causes poor Al electrodeposition. Formation of flaky/dendritic deposits ultimately causes loss of active aluminium (dead metal) during discharge reducing the overall efficiency.
Although the are several challenges identified, good results and clear advancements have been made in the synthesis of novel materials and methods. These have been either published in peer review scientific journals in Open Acess or patented, in the case of KRE1.
At the end of the project, up to 5 Key Exploitable results have been identified, namely
- KER1: A novel membrane has been developed and patented. It can act as functional separator and endures the contact with the corrosive electrolytes. This membrane, which level of porosity and thickness can be tuned, have shown its potential to be used in combination, not only with chloroaluminates, but also in other liquid electrolytes maintaining conductivity. Results have shown show that the use of the membrane in combination with the developed electrolyte enables or improves cyclability which is otherwise very poor.
- KER2: Sulfur electrode formulation to be combined with an aluminium electrode to produce a rechargeable battery.
- KER3: Anode performance can be improved by using active PVD-Al on inert current collector foil.
- KER4&5: Method of synthesis for chloroaluminate ionic liquid analogues (deep eutectic solvent) and New electrolyte formulations based on amidines and amidinium cations
Dissemination activities have included the participation in several actions organized by the EIC, participation in seminars, congresses and conferences. Moreover a devoted workshop was organised and an specific symposium in the frame of a scientific congress.
