A Ga–Sn liquid metal-mediated structural cathode for Li–O2 batteries. (December 2020)

• Record Type: Journal Article
• Authors: Luo, Z.; Ji, C.; Yin, L.; Zhu, G.; Xu, B.B.; Wang, Y.; Liu, T.X.; Zhuge, X.; Luo, K.
• Is Part Of: Materials today energy. Volume 18(2020)
• Publication Date: 2020-12
• Subjects: Li–O2 batteries -- Ga–Sn liquid metal -- Flaky Li2O2 -- Cathode passivation; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2020.100559
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: One of the recent challenges in Li–O2 battery technology is the cycle life, which can be severely shortened by cathode passivation induced by discharge product accumulation; this can be eliminated by reducing the amount of discharge products. Herein, we report a feasibility study on the development of a Ga–Sn liquid metal (LM)-functionalized multiwalled carbon nanotubes (MWNTs) cathode. In a comparison of MWNT, LM, m-LM/MWNT (pre-mixed LM and MWNTs), and LM/MWNT (LM-modified MWNTs) cathodes, morphology analysis showed that small Li2 O2 flakes rather than large crystals grow on the conductive Ga–Sn LM and MWNTs of the LM/MWNT cathode only. The decomposition of the flaky Li2 O2 on the LM/MWNT cathode occurred at lower charge overpotentials, resulting in low polarization; thus, the cathode passivation and the consumption of the Li anode were both alleviated during the cyclic process. The LM/MWNT cathode significantly improved the cycle life, rate performance, and ultimate capacity of Li–O2 batteries. Graphical abstract: Image 1 Highlights: The Ga–Sn LM/MWNT cathode extends the cycle life of LOBs to up to four times that of the MWNT cathode. The discharge capacity of the Ga–Sn LM/MWNT cathode is approximately 7.4 times higher than that of the MWNT cathode. The Ga–Sn LM/MWNT cathode induces the formation of flaky Li2 O2 with smaller particles. Li anode corrosion is alleviated by using the Ga–Sn LM/MWNT cathode.