Free-standing hybrid film of less defective graphene coated with mesoporous TiO2 for lithium ion batteries with fast charging/discharging capabilities

doi:10.1088/2053-1583/4/1/015011

IMR OpenIR

	Free-standing hybrid film of less defective graphene coated with mesoporous TiO2 for lithium ion batteries with fast charging/discharging capabilities
	Feng,Bingmei 1,3; Wang,Huixin 1; Zhang,Yingqi 1; Shan,Xuyi 2; Liu,Min 2; Li,Feng 2; Guo,Jinghua 3; Feng,Jun 3; Fang,Hai-Tao 1
	2016-11-04
发表期刊	2D Materials
ISSN	2053-1583
卷号	4 期号:1
摘要	Abstract Benefiting from extremely high conductivity, graphene sheets (GS) with very low defect density are preferable to reduced graphene oxide sheets for constructing the free-standing hybrid electrodes of flexible electrochemical energy storage devices. However, due to the hydrophobic nature and deficiency of nucleation sites, how to uniformly and intimately anchor electrochemically active materials onto less defective GS is a challenge. Herein, a free-standing and mechanically flexible hybrid film with two-layer structure, mesoporous TiO2 anchored less defective GS hybrid (mTiO2-GS) upper-layer and graphene under-layer, denoted as mTiO2-GS/G, is fabricated. The hydrolysis of a Ti glycolate aqueous sol solution were applied to form mTiO2. The decoration of less defective GS with sodium lignosulfonate (SLS) surfactant is crucial for anchoring TiO2 nanoparticles (NPs). The aromatic rings of SLS favor a non-destructive functionalization of GS through the π-π stacking interaction. The sulfonic acid groups and hydroxyl groups of SLS, respectively, greatly improve the dispersity of GS in water and trigger the nucleation of TiO2 through the oxolation in the hydrolysis of Ti glycolate sol solution. The following characteristics of free-standing mTiO2-GS/G electrode benefit the fast charging/discharging capabilities: highly conductive graphene framework, ultra-small NPs (～5.0 nm) in mTiO2 anchored, high specific surface area (202.5 m2 g?1), abundant mesopores (0.32 cm3 g?1), intimate interfacial interaction between mTiO2 and GS, robust contact between the mTiO2-GS upper-layer and an under-layer of bare graphene as the current collector. In coin half-cells, the mTiO2-GS/G electrode delivers a capacity of 130 mA h g?1 at 50 C, and 71 mA h g?1 at 100 C, and it also exhibits excellent cycle stability up to 10 000 cycles under 10 C, with a degradation rate of 0.0033% per cycle. When packed in flexible cells, the mTiO2-GS/G electrode maintains fast charging/discharging capabilities regardless of being flat or bent. Furthermore, because of the high durability of mTiO2-GS/G electrode, repeated deformations do not cause extra capacity degradation.
关键词	mesoporous TiO2 graphene flexible electrode lithium ion battery
DOI	10.1088/2053-1583/4/1/015011
语种	英语
WOS记录号	IOP:2053-1583-4-1-015011
出版者	IOP Publishing
引用统计
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/80492
专题	中国科学院金属研究所
作者单位	1.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, People’s Republic of China 2.Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China 3.Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
推荐引用方式 GB/T 7714	Feng,Bingmei,Wang,Huixin,Zhang,Yingqi,et al. Free-standing hybrid film of less defective graphene coated with mesoporous TiO2 for lithium ion batteries with fast charging/discharging capabilities[J]. 2D Materials,2016,4(1).
APA	Feng,Bingmei.,Wang,Huixin.,Zhang,Yingqi.,Shan,Xuyi.,Liu,Min.,...&Fang,Hai-Tao.(2016).Free-standing hybrid film of less defective graphene coated with mesoporous TiO2 for lithium ion batteries with fast charging/discharging capabilities.2D Materials,4(1).
MLA	Feng,Bingmei,et al."Free-standing hybrid film of less defective graphene coated with mesoporous TiO2 for lithium ion batteries with fast charging/discharging capabilities".2D Materials 4.1(2016).