文章信息/Info

Title:

Preparation and Hydrogen Storage Properties of Li-Al-B-H Composites

文章編號:

1674-3962(2023)01-0039-07

作者:

羅輝; 王新春; 陶小馬; 黃存可; 藍志強; 周文政; 郭進; 劉海鎮

（廣西大學物理科學與工程技術學院，廣西 南寧 530004）

Author(s):

LUO Hui;  WANG Xinchun;  TAO Xiaoma;  HUANG Cunke;  LAN Zhiqiang;  ZHOU Wenzheng;  GUO Jin;  LIU Haizhen

(School of Physical Science and Technology, Guangxi University, Nanning 530004, China)

關鍵詞:

儲氫材料; 硼氫化鋰; 納米鋁粉; AlB2; Li-Al-B相; 儲氫性能

Keywords:

hydrogen storage materials;  lithium borohydride;  nano-Al powder;  AlB2 powder;  Li-Al-B;  hydrogen storage properties

分類號:

TK912

DOI:

10.7502/j.issn.1674-3962.202209006

文獻標志碼:

A

摘要:

硼氫化鋰（LiBH4）的有效儲氫密度可達13.6%（質量分數，下同），是一種具有潛在應用前景的儲氫材料。但是，LiBH4的熱力學穩定性高，導致其吸放氫溫度高，且其吸放氫動力學差，可逆條件苛刻，嚴重限制了其實際應用。針對這些問題，以普通Al粉（記為“Al”）和納米Al粉（記為“nano-Al”）作為改性添加劑，采用機械球磨法制備了LiBH4+0.5Al和LiBH4+0.5nano-Al（物質的量之比）這2種Li-Al-B-H復合儲氫材料，并通過X射線衍射（XRD）、吸放氫測試、熱分析等手段研究了2種Al粉制備的Li-Al-B-H復合儲氫材料的微結構和放氫性能。放氫性能研究表明，添加Al后，LiBH4的放氫溫度得到降低，且以納米Al粉構建的Li-Al-B-H復合儲氫材料具有比以普通Al粉構建的Li-Al-B-H復合儲氫材料更優異的放氫性能和循環性能。放氫產物微結構研究表明，在放氫過程中，LiBH4會與Al發生反應生成AlB2和Li-Al-B相，這是LiBH4吸放氫性能提高的關鍵。另外，由于納米Al的顆粒尺寸小，比表面積大，反應界面更多，使得LiBH4+0.5nano-Al放氫后生成的AlB2和Li-Al-B相的量比LiBH4+0.5Al更多，這是LiBH4+0.5nano-Al放氫性能優于LiBH4+0.5Al的原因。研究結果將為進一步理解Li-Al-B-H復合儲氫材料的儲氫性能和儲氫機理提供參考。

Abstract:

Lithium borohydride (LiBH4) is a promising hydrogen storage material due to its large effective hydrogen storage capacity of 13.6wt%. However, the high thermodynamic stability resulting in high hydrogen absorption and desorption temperature, poor hydrogen absorption and desorption kinetics, and harsh reversibility conditions seriously limit its practical application. In response to these problems, two kinds of Li-Al-B-H composites (LiBH4+0.5Al and LiBH4+0.5nano-Al) were prepared by mechanical ball milling method using ordinary Al powder (written as “Al”) and nanoscale Al powder (written as “nano-Al”) as modification additives. The microstructures and hydrogen desorption properties of the Li-Al-B-H composites prepared with different Al powders were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), hydrogen absorption and desorption tests, and thermal analysis. The hydrogen desorption performance study shows that the hydrogen desorption temperature of LiBH4 is reduced after adding Al, and the L-Al-B-H composite constructed with nano�睞l has better hydrogen releasing performance and cycling performance than the Li-Al-B-H composite constructed with ordinary Al powder. The microstructure study of the hydrogen desorption product shows that during the hydrogen desorption process, LiBH4 reacts with Al to form AlB2 and Li-Al-B phases, which is the key to the improvement of the hydrogen absorption and desorption performance of LiBH4. In addition, due to the smaller particle size, the nano�睞l has larger specific surface area and more reaction interfaces, which leads to that the amount of AlB2 and Li-Al-B phases generated after LiBH4+0.5nano-Al dehydrogenation is more than that of LiBH4+0.5Al. This is the reason why the hydrogen releasing performance of LiBH4+0.5nano-Al is better than that of LiBH4+0.5Al. This work provides an important reference for further understanding the hydrogen storage performance and hydrogen storage mechanism of Li-Al-B-H hydrogen storage materials.