The energy transition demands green storage, where batteries are very effective in short-term and efficient energy storage for electronics, electrical mobility and stabilization of a smart electricity network. Battery demands are rising 20% per year making the need for usage of non-critical materials and circular processes an urgent requirement. None of the current rechargeable battery technologies can fully satisfy all the challenging requirements for our future energy storage applications, regarding energy density, charging time, lifetime, safety, circularity and sustainability. Furthermore, to answer these demands in a sustainable way, a new battery technology needs to be developed based on abundant elements (without lithium, cobalt, nickel, etc.), low CO2 emission production and circular system design, while maintaining decent energy storage performance for mobility (e.g. range > 400 km) and stationary applications (e.g. low costs and long cycle life).
The Challenge: Novel battery technologies based on sodium-ion chemistries with abundant and renewable elements are currently being explored. Sodium ions can be extracted from salt (sodiumchloride) with a much smaller CO2 footprint as compared to lithium mining. Salt (water) is present all over the world preventing geopolitical issues about its availability. Furthermore, sodium-ion cathodes with promising performance can be based on abundant elements (e.g. iron, manganese) in strong contrast to the required cobalt and nickel in conventional lithium-ion batteries. However, the central challenge is to realize the combination of a high energy/high power density and a long cycle life for sodium-ion batteries based on non-critical materials. Poor reversibility of the energy storage process due to parasitic reactions and unfavourable structural rearrangements/phase transitions are at the origin of such poor performance and eventually battery failure.
Combatting these degradations requires firstly in-depth understanding of the materials processes taking place, and secondly it requires materials solutions/design that prevent these detrimental processes. Furthermore, synthesis methods of these new sodium-ion chemistries need to be translated to sustainable, large scale production processes, which may be different from the current production of conventional lithium-ion batteries. The opportunities lie in (1) detailed characterization by innovative operando techniques for enhanced analysis during battery operation to deliver fundamental understanding of the degradation phenomena occurring at the electrode/electrolyte interfaces in sodium-ion batteries to enable (2) the development of new electrode and electrolyte materials for next-generation sodium-ion batteries with pronounced advantages regarding their performance as well as the use of sustainable materials and production methods.
More information : Mark Huijben (m.huijben@utwente.nl)