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(lán)志強(qiáng); 周文政; 郭進(jìn); 劉海鎮(zhèn)

（廣西大學(xué)物理科學(xué)與工程技術(shù)學(xué)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(guān)鍵詞:

儲(chǔ)氫材料; 硼氫化鋰; 納米鋁粉; AlB2; Li-Al-B相; 儲(chǔ)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(xiàn)標(biāo)志碼:

A

摘要:

硼氫化鋰（LiBH4）的有效儲(chǔ)氫密度可達(dá)13.6%（質(zhì)量分?jǐn)?shù)，下同），是一種具有潛在應(yīng)用前景的儲(chǔ)氫材料。但是，LiBH4的熱力學(xué)穩(wěn)定性高，導(dǎo)致其吸放氫溫度高，且其吸放氫動(dòng)力學(xué)差，可逆條件苛刻，嚴(yán)重限制了其實(shí)際應(yīng)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(jī)械球磨法制備了LiBH4+0.5Al和LiBH4+0.5nano-Al（物質(zhì)的量之比）這2種Li-Al-B-H復(fù)合儲(chǔ)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(fù)合儲(chǔ)氫材料的微結(jié)構(gòu)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(gòu)建的Li-Al-B-H復(fù)合儲(chǔ)氫材料具有比以普通Al粉構(gòu)建的Li-Al-B-H復(fù)合儲(chǔ)氫材料更優(yōu)異的放氫性能和循環(huán)性能。放氫產(chǎn)物微結(jié)構(gòu)研究表明，在放氫過程中，LiBH4會(huì)與Al發(fā)生反應(yīng)生成AlB2和Li-Al-B相，這是LiBH4吸放氫性能提高的關(guān)鍵。另外，由于納米Al的顆粒尺寸小，比表面積大，反應(yīng)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(yōu)于LiBH4+0.5Al的原因。研究結(jié)果將為進(jìn)一步理解Li-Al-B-H復(fù)合儲(chǔ)氫材料的儲(chǔ)氫性能和儲(chǔ)氫機(jī)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.