Achieving High Dehydrogenation Kinetics and Reversibility of LiBH4 by Adding Nanoporous h-BN to Destabilize LiH

作者:Zhu, JY (Zhu, Jiuyi)^[1,2 ]; Wang, H (Wang, Hui)^[1,2 ]; Liu, JW (Liu, Jiangwen)^[1,2 ]; Ouyang, LZ (Ouyang, Liuzhang)^[1,2 ]; Zhu, M (Zhu, Min)^[1,2 ]

Lithium borohydride (LiBH4) is a potential high-capacity hydrogen storage material but is limited by its high thermal stability and poor reversibility. Nanostructured hexagonal boron nitrides (h-BNs) with thin-layer (TL-BN) and nanoporous (NP-BN) structures have been prepared by treating h-BN in a hydrolysis process of LiBH4 and then mixing with LiBH4 by ball-milling to investigate their catalyzing effect on dehydrogenation and rehydrogenation. Nanostructured h-BN, in particular NP-BN, with an average pore size of 40 nm, significantly promotes the dehydrogenation kinetics, dehydrogenation capacity, and reversibility of LiBH4. For a LiBH4 + NP-BN (mole ratio 1:0.3) composite, the dehydrogenation capacity reaches 13.9 wt % for LiBH4 at 400 degrees C, which is very close to its theoretical one. The cycling capacity could remain stable at, similar to 7.6 wt % with rapid kinetics after de/rehydrogenation cycles under 10 MPa of hydrogen at 400 degrees C. The improved de/hydrogenation performance of LiBH4 depends on the nanoconfinement structure of LiBH4 in NP-BN. After dehydrogenation, a lithium-intercalated h-BN(LixBN) nanocrystal was formed by the reaction of h-BN and LiH. This LixBN nanocrystal confined the dehydrogenation products of the amorphous structure during dehydrogenation. Thus, this nanocrystal-confine-amorphous structure destabilizing LiH and benefiting the rehydrogenation and reversible capacity of the composite.

KeyWords Plus:HEXAGONAL BORON-NITRIDE; HYDROGEN-STORAGE MATERIALS; REHYDROGENATION PROPERTIES; METAL-BOROHYDRIDES; AMMONIA BORANE; NANOTUBES; RELEASE; MG; DECOMPOSITION; NANOPARTICLES

通讯作者地址:Zhu, M (通讯作者)

South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510640, Guangdong, Peoples R China.   增强组织信息的名称     South China University of Technology

South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510640, Guangdong, Peoples R China.   增强组织信息的名称     South China University of Technology

地址:

	[ 1 ] South China Univ Technol, Sch Mat Sci & Engn, Guangzhou 510640, Guangdong, Peoples R China   增强组织信息的名称     South China University of Technology
	[ 2 ] South China Univ Technol, Key Lab Adv Energy Storage Mat Guangdong Prov, Guangzhou 510640, Guangdong, Peoples R China   增强组织信息的名称     South China University of Technology

电子邮件地址:memzhu@scut.edu.cn

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