Rechargeable lithium-ion batteries, composed of two lithium insertion electrodes and a conductive lithium-ion electrolyte, have become efficient energy storage devices since the first sale of lithium-ion batteries (LIBs) in 1991. LIBs based on cobalt/nickel as positive electrodes were originally designed as a high energy source for portable electronic devices, with an energy limited to less than 100 Wh as a single battery. Recently, large-scale LIBs have been developed and used as an alternative energy source for electric vehicles (energy of 5-20 KWh for electric vehicles). This could reduce the energy dependence of fossil fuels for a public transport system.

Most LIB technologies today consist of expensive cobalt-based materials such as positive electrodes, so there is a need to find new alternatives in order to reduce the costs of LIBs, especially for large energy storage systems. For this reason, LIBs with a scale of megawatt hours (MWh) are being developed to store electricity produced from renewable energy resources. In addition, the price and scarcity of lithium is another factor to consider. For this reason, scientists consider rechargeable sodium-ion batteries (SIBs) to be an alternative to LIBs [1], as it is one of the most abundant elements of the earth’s crust (Figure 1).

Figure 1: Elemental abundance in the Earth’s crust, towards Sodium-ion from Lithium-ion batteries [1].

In fact, developments in LIB technology have accelerated the development of NIBs, including studies on electrode materials, electrolyte and interface/interphase. Before 2010, the most difficult problem facing the demonstration of NIBs was the ability to insert sodium into negative electrodes and the batteries lifetime. Recently, highly efficient negative electrode materials for NIBs were discovered. These negative electrodes are key materials for performing high energy density performance NIBs (Figure 2). However, additional studies are necessary not only for electrode materials but also for electrolytes, additives and binders. In addition, a better understanding of the interface electrode/electrolyte is necessary to achieve new breakthroughs. For this, theoretical approaches have recently been applied to study this interface on the atomic scale, for both LIBs and NIBs systems.

Figure 2: Average voltage and energy density versus gravimetric capacity for various electrodes materials for NIBs [2].



[1] N. Yabuuchi, K. Kubota, M. Dahbi, S. Komaba, Research development on sodium-ion batteries, Chemical Review, 114, 11636–11682 (2014)

[2] M. Dahbi, N. Yabuuchi, K. Kubota, K. Tokiwa, S. Komaba, Negative electrodes for Na-ion batterie, Physical Chemistry Chemical Physics, 16, 15007-15028 (2014)