摘要
针对传统水系镍氢电池电化学窗口较窄以及能量密度较低的缺点,基于硅材料优异的储氢性能,采用射频磁控溅射方法和后气体氢化处理分别制备非晶硅(a-Si)和氢化非晶硅(a-Si:H)薄膜作为镍氢电池负极材料,通过XRD、TEM、XPS、SEM、EDS和电化学测试等方法研究了气体氢化处理前后非晶硅薄膜结构以及其在质子型离子液体中的电化学性能。结果表明,溅射所制备的硅薄膜呈非晶态,溅射后在硅薄膜与镍衬底界面处形成了硅镍化合物相,且溅射时非晶硅薄膜有一定程度的氧化。经气体氢化处理后,非晶硅薄膜中硅与氢形成SiH、SiH2和SiH3三种键合方式,并伴有少量的非晶硅晶化发生,薄膜发生一定程度的剥落,且氧化程度加重。电化学测试分析表明,溅射态非晶硅薄膜电极的放电容量很低(113 mAh·g^(-1)),气体氢化后的非晶硅薄膜电化学性能显著改善,当气体氢化30 min时薄膜电极具有最大的放电容量480 mAh·g^(-1),其充放电20个循环后其容量仍未衰减。
Aims at the disadvantages of low capacity density and narrow electrochemical window of conventional nickel-hydrogen batteries,combined with the excellent hydrogen storage performance of silicon materials,the amorphous silicon(a-Si)and hydrogenated amorphous silicon(a-Si:H)films were prepared by RF magnetron sputtering following gas hydrogenation as anode materials for Ni-MH batteries.The structure of amorphous silicon films and their electrochemical properties in proton ionic liquids were studied by XRD、TEM、XPS、SEM、EDS and electrochemical measurements.The results show that the silicon thin films prepared by sputtering are amorphous,and the silicon-nickel compound phase is formed at the interface between the silicon thin films and the nickel substrate.Moreover,the amorphous silicon film has some degree of oxidation during sputtering.After gas hydrogenation treatment,silicon and hydrogen form three bonding modes of SiH、SiH2 and SiH3 in amorphous silicon films,accompanied by a small amount of amorphous silicon crystallization,the film has a certain degree of exfoliation,and the oxidation is aggravated.The electrochemical test analysis shows that the discharge capacity of the sputtered amorphous silicon thin film electrode is very low(113 mAh·g^(-1)),and the electrochemical performance of the amorphous silicon thin film after gas hydrogenation is significantly improved.The film electrode hydrogenated 30 min has a maximum discharge capacity of 480 mAh·g^(-1),and its capacity is still not attenuated after 20 charge-discharge cycles.
作者
尤超
张海民
杨淞婷
罗永春
YOU Chao;ZHANG Haimin;YANG Songting;LUO Yongchun(Department of Materials Science and Engineer,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;School of Science,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou 730050,Gansu,China)
出处
《金属功能材料》
CAS
2021年第5期62-68,共7页
Metallic Functional Materials
关键词
非晶硅薄膜
磁控溅射
气体氢化处理
质子型离子液体
电化学性能
amorphous silicon film
megnetron sputtering
gas hydrogenated treatment
proton ionic liquid
electrochemical properties
