Low Cost Sodium-Aluminum Dual-Ion Batteries for High C-Rate Performance

With the global transition to clean energy, lithium-ion batteries have become the industry standard for light, energy dense batteries in electric vehicles and grid-scale storage. However, with increasing demand for lithium and scarce reserves, the cost of lithium has been increasing. Additionally, lithium metal is highly reactive and prone to dendrite formation which can lead to short circuits and battery fires ^[1]. To combat these challenges, researchers have explored various multivalent ion systems (Na⁺, K⁺, Ca²⁺, Mg²⁺, Al³⁺) to find a safer and energy dense alternative to lithium-ion batteries ^[2,3]. Another approach to solve this challenge has been to focus on dual-ion systems, such as Li-Na and Na-Al, which contain multiple active ions and have a wide operating voltage range ^[4]. While dual-ion systems show great potential, tuning the electrolyte and cathode to host both mobile ions is often a challenge.

In this work, we explore a sodium-aluminum dual-ion system which is stable up to 2.4V (vs Al/ Al³⁺). A cathode material has been synthesized to host both Na and Al ions which coupled with an aluminum metal anode shows excellent electrochemical performance over a wide range of temperatures and C-rates up to 10C. A further study has been done to understand the intercalation mechanism of the dual-ions in this system.

References –
1) Kim, Taehoon, et al. “Lithium ion Batteries: Outlook on Present, Future, and Hybridized Technologies.” Journal of Materials Chemistry A, vol. 7, no. 7, Jan. 2019, pp. 2942–64. https://doi.org/10.1039/c8ta10513h.

2) Kubota, Kei, et al. “Towards K Ion and Na Ion Batteries as ‘Beyond Li Ion.’” The Chemical Record, vol. 18, no. 4, Feb. 2018, pp. 459–79. https://doi.org/10.1002/tcr.201700057.

3) Yang, Yujie, et al. “Prussian Blue and Its Analogues as Cathode Materials for Na-, K-, Mg-, Ca-, Zn- and Al-ion Batteries.” Nano Energy, vol. 99, May 2022, p. 107424. https://doi.org/10.1016/j.nanoen.2022.107424.

4) Wang, Meng, and Yongbing Tang. “A Review on the Features and Progress of Dual Ion Batteries.” Advanced Energy Materials, vol. 8, no. 19, Mar. 2018, https://doi.org/10.1002/aenm.201703320.