A sodium–aluminum hybrid battery12. Issue 14 (20th March 2017)

• Record Type: Journal Article
• Authors: Sun, Xiao-Guang; Zhang, Zhizhen; Guan, Hong Yu; Bridges, Craig A.; Fang, Youxing; Hu, Yong-Sheng; Veith, Gabriel M.; Dai, Sheng
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 14(2017)
• Page Start: 6589
• Page End: 6596
• Publication Date: 2017-03-20
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta00191f
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A hybrid battery based on an aluminum anode, a sodium insertion cathode Na3 V2 (PO4 )3, and a sodium/aluminum dual salt electrolyte has been demonstrated. The hybrid battery exhibits a discharge voltage of 1.25 V and a cathodic capacity of 99 mA h g −1 at a current rate of C/10. It also shows good rate performance and long-term cycling stability while maintaining a high coulombic efficiency of 98%. Abstract : Novel hybrid batteries are fabricated using an aluminum anode, a sodium intercalation cathode Na3 V2 (PO4 )3 (NVP), and a sodium/aluminum dual salt electrolyte based on NaAlCl4 and an eutectic mixture of 1-ethyl-3-methylimidazolium chloride (EMImC) and aluminum chloride. Cyclic voltammograms indicate that increasing the molar concentration of AlCl3 in the electrolyte is beneficial to high coulombic efficiency of aluminum deposition/stripping, which, unfortunately, results in lower coulombic efficiency of sodium extraction/insertion in the cathode. Therefore, EMImC–AlCl3 with a molar ratio of 1–1.1 is used for battery evaluation. The hybrid battery with 1.0 M NaAlCl4 exhibits a discharge voltage of 1.25 V and a cathodic capacity of 99 mA h g −1 at a current rate of C/10. In addition, the hybrid battery exhibits good rate performance and long-term cycling stability while maintaining a high coulombic efficiency of 98%. It is also demonstrated that increasing salt concentration can further enhance the cycling performance of the hybrid battery. X-ray diffraction analysis of the NVP electrodes under different conditions confirms that the main cathode reaction is indeed Na extraction/insertion. Based on all earth-abundant elements, the new Na–Al hybrid battery is very attractive for stationary and grid energy storage applications.