Dehydrogenation properties of two phases of LiNH2BH3. (13th January 2020)

• Record Type: Journal Article
• Authors: Liu, Xiaoran; Wang, Shumao; Wu, Yuanfang; Li, Zhinian; Jiang, Lijun; Guo, Xiumei; Ye, Jianhua
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 3(2020)
• Page Start: 2127
• Page End: 2134
• Publication Date: 2020-01-13
• Subjects: Hydrogen storage -- Ball milling -- α-LiNH2BH3 -- β-LiNH2BH3 -- Dehydrogenation; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2019.11.105
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Lithium amidoborane (LiNH2 BH3 ) is known as one of the most prospective hydrogen storage materials. In this paper, the differences between two allotropes (α-LiNH2 BH3 and β-LiNH2 BH3 ) of LiNH2 BH3 in the dehydrogenation properties was reported for the first time. A series of mixtures of α-LiNH2 BH3 /β-LiNH2 BH3 with different mass ratios were prepared by ball milling for different time and the contents of two phases in samples were determined with Rietveld's method. The thermal decomposition behaviors of samples were investigated by DSC. It shows that the initial dehydrogenation temperature of samples decreases with the content of α-LiNH2 BH3 phase increasing. The initial dehydrogenation temperature of α-LiNH2 BH3 is about 61 °C, which is approximately 15 °C lower than that of β-LiNH2 BH3 . Dehydrogenation kinetic analysis shows that α-LiNH2 BH3 has the lower activation energy (157 kJ mol −1 ) and higher rate ( k = 1.422 × 10 1 min −1 ) than that of β-LiNH2 BH3 (272 kJ mol −1 and 1.023 × 10 −1 min −1, respectively). It is suggested that α-LiNH2 BH3 is more supportive for hydrogen desorption. It gives a critical clue on exploring the dehydrogenation mechanism of lithium amidoborane. Moreover, the significant decrease of desorption temperature will shine a light on on-board hydrogen storage systems. Highlights: The two allotropes of LiNH2 BH3 have different dehydrogenation properties. The onset dehydrogenation temperature of α-LiNH2 BH3 is lower than that of β-LiNH2 BH3 . α-LiNH2 BH3 has the lower activation energy and higher rate than that of β-LiNH2 BH3 .