Title : Dimensionality of MnO2 cathodes as a key factor governing kinetics in Alumninium-ion batteries
Along with the non-stopping technological expansion, modern societies are in need of a constant energetic supply. Equipment with a stationary and non-stationary objective must have battery or capacitor devices adapted to its requirements, where energy storage has to be efficient. The Lithium-ion technology remains the most demanded system. However, the high cost and limited amount of lithium available has led to research for alternative systems: Na, K, Mg, Al, Ca and Zn . One of the most promising alternative among next-generation energy storage system is the aluminium-ion battery (AIB) which has a higher theoretical volumetric (8046 mA h cm-3) and gravimetric (2980 mA h g-1) capacity, but also due to its low cost, sustainability and low flammability [2,3].
Electrochemical activity of different MnO2 phases as electrodes of aluminium-ion batteries (AIBs) is studied. For this purpose, different simple synthesis routes have been carried out to obtain on the one hand, MnO2 rod-like with tunnelled structure (α-MnO2) and on the other MnO2 hexagonal micro-pellets with lamellar structure (δ-MnO2). α-MnO2 showed an outstanding capacity (Q) of 120 mA h g-1 at current densities of 100 mA g-1, which remains stable after 100 cycles with efficiencies over 90%. δ-MnO2 showed a good capacity of 80 mA h g-1 at current densities of 50 mA g-1 after 50 cycles and with efficiencies over 95%. Moreover, cyclic voltammetry (CV) measurements at different rates allowed for a better understanding of the electrochemical behaviour and revealed the contribution relation of diffusive and capacitive-controlled mechanisms in the corresponding AIB system. Further cyclic voltammetry (CV) measurements at different rates allowed a kinetic study of the diffusive and capacitive-controlled mechanisms. The results were interpreted concerning the influence of dimensionality (1D and 2D) of the MnO2 phases obtained.
- New battery technologies
- Learn about rechargeable aluminium batteries
- Understand the importance of the chemical and physical structure of materials in their electrochemical behaviour.