High energy density sodium-ion (Na-ion) batteries are now close to successful commercialization. These energy storage devices offer some significant advantages over their lithium-ion counterparts, such as lower material costs, improved safety characteristics and superior transportation properties [1,2]. In this study we demonstrate the electrochemical performance characteristics of full Na-ion cells constructed using a proprietary layered oxide cathode Na_aNi_(1-x-y-z)Mn_xMg_yTi_zO₂ and a hard carbon anode material [3].

Figure 1 depicts the voltage profile for a typical Faradion Na-ion cell. The cathode material delivers a reversible specific capacity of over 146 mAh/g and the cell generates an average discharge cell voltage of around 3.2 V. The projected specific energy for this battery system is 140-150 Wh/kg. The cell cycles with low polarization and with excellent columbic and (round-trip) energy efficiency. Figure 2 denotes a typical cycle life plot (100 % DOD) for a representative Na-ion cell. Following 170 cycles the discharge capacity fade is less than 1%. Simple linear extrapolation indicates that this cell should cycle 1000 cycles while maintaining well over 90% of its original discharge capacity.

To demonstrate the commercial viability of Na-ion batteries, Faradion has scaled-up this cell chemistry to the 3 Ah (9 Wh) prismatic pouch cell level. These cells were fabricated using traditional Li-ion manufacturing methods. Multiple prototype cells have been incorporated successfully into E-Bike (>400 Wh) and E-Scooter (>750 Wh) demonstrator packs [4,5]. 

Further performance and safety characteristics of the Na-ion cells will be provided during the presentation.

References:

1.  V. Palomares, P. Serras, I. Villaluenga, K. B. Hueso, J. Carretero-Gonzalez and T. Rojo, Energy Environ. Sci. 2012, 5, 5884. 

2.  J. Barker, M.Y. Saidi and J. Swoyer, Electrochem. Solid-State Chem. 2003, 6, A1 

3.  For example, J. Barker and R.J. Heap, PCT Patent App. WO/2014/057258 (filed October 2013)

4.  J. Barker and C. J. Wright. Presentation at the Advanced Automotive and Stationary/Industrial Battery Conference, AABC, Detroit, Michigan, USA, June 2015

5.  J. Barker, R.J. Heap, N. Roche, C. Tan, R. Sayers. J. Whitley and Y. Liu. Presentation at the 2^nd International Symposium on Sodium Batteries, Phoenix, Arizona, USA, October 2015