The need for energy storage is in some cases very perceivable in our day-to-day lives, e.g. portable electronics and electrified vehicles, while in other cases this equally pressing need is less tangible, e.g. the transition of energy production from fossil fuels to renewable sources to balance energy production and consumption peaks. Nowadays, the lithium-ion battery (LIB) is one of the most mature and widely known energy storage technology offering high energy efficiency as well as high energy density. However, excessive consumption of costly and scarce elements, e.g. Li and Co, leads to major concerns about deployment of Li-ion batteries for large-scale energy storage. Consequently, interest in alternative more abundant metals such as sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), zinc (Zn), and aluminum (Al) have increased during the last decade (see figure comparing them). Among all of them, Aluminum presents a series of distinct advantages:
- high energy density (8040 Ah L-1)
- low cost (Al is the most abundant metal in the Earth´s crust) and
- safety, it can be easily handle in air conditions.
Unfortunately, Al-based batteries still face a series of challenges to become a competitive alternative to other mature technologies. The low capacity per cm2 of electrode demonstrated in the state-of-the-art has drastic detrimental implications on the specific energy as well as cost preventing market penetration of Al batteries.
Researches of the Electrochemical Processes Unit at IMDEA Energy* have proposed a new Al-based battery technology, which uses for the first time semi-solid electrodes for Al-ion batteries. The authors not only demonstrate the proof-of-concept for this battery technology, but also achieve impressive performance figures, e.g. 5-fold increase in capacity per cm2 of electrode with respect to the state-of-the-art. In their work, it is shown that battery performance improvement derived from the enhanced mass transport of ions through thick electrode (at least 1.8 times higher) and the versatility of the concept by implementing it to two types of active materials.
The values achieved in this proof-of-concept are very encouraging since the use of novel advanced cathode materials together with further understanding and optimization of semi-solid electrodes will lead to improved electrochemical performances lowering costs and making this technology more competitive for stationary energy storage.
(*) Muñoz-Torrero, D., Palma, J., Marcilla, R., Ventosa, E. Al-Ion Battery Based on Semisolid Electrodes for Higher Specific Energy and Lower Cost. (2020) ACS Applied Energy Materials.
More information: Jesús Palma, Head of the Electrochemical Processes Unit firstname.lastname@example.org