物理化学学报2017，Vol.33Issue(2)：377-385,9.DOI:10.3866/PKU.WHXB201610272
锂离子电池用三维氧化锡/石墨烯水凝胶负极材料
3D SnO2/Graphene Hydrogel Anode Material for Lithium-Ion Battery
摘要
Abstract
With the widespread use of mobile electronic devices and increasing demand for electric energy storage in the transportation and energy sectors,lithium-ion batteries (LIBs) have become a major research and development focus in recent years.The current generation of LIBs use graphite as the anode material,which has a theoretical capacity of 372 mAh ·g-1.Tin-based materials are considered promising anode materials for next-generation LIBs because of their favorable working voltage and unsurpassed theoretical specific capacity.However,overcoming the rapid storage capacity degradation of tin caused by its large volumetric changes (＞ 200％) during cycling remains a major challenge to the successful implementation of such materials.In this paper,SnO2 nanoparticles with a diameter of 2-3 nm were used as active materials in LIB anodes and a three dimensional (3D) graphene hydrogel (GH) was used as a buffer to decrease the volumetric change.Typically,SnCl,aqueous solution (18 mL,6.4 mmol· L-1) and graphene oxide (GO) suspension (0.5％ (w,mass fraction),2 mL) were mixed together via sonication.NaOH aqueous solution (11.4 mmol· L-1,40 mL) was slowly added and then the mixture was stirred for 2 h to obtain a stable suspension.Vitamin C (VC,80 mg) was then added as a reductant.The mixture was kept at 80 ℃ for 24 h to reduce and self-assemble.The resulting black block was washed repeatedly with distilled deionized water and freeze-dried to obtain SnO2-GH.In this composite,GH provides large specific surface area for efficient loading (54％ (w)) and uniform distribution of nanoparticles.SnO2-GH delivered a capacity of 500 mAh·g-1 at 5000 mA·g-1 and 865 mAh·g-1 at 50 mA·g-1 after rate cycling.This outstanding electrochemical performance is attributed to the 3D structure of GH,which provides large internal space to accommodate volumetric changes,an electrically conducting structural porous network,a large amount of lithium-ion diffusion channels,fast electron transport kinetics,and excellent penetration of electrolyte solution.This study demonstrates that 3D GH is a potential carbon matrix for LIBs.关键词
石墨烯水凝胶/氧化锡/锂离子电池/负极/三维Key words
Graphene hydrogel/SnO2/Lithium-ion battery/Anode/Three-dimension分类
化学化工引用本文复制引用
白雪君,侯敏,刘婵,王彪,曹辉,王东..锂离子电池用三维氧化锡/石墨烯水凝胶负极材料[J].物理化学学报,2017,33(2):377-385,9.基金项目
The project was supported by the Shanghai Science and Technology Innovation Plan,China (15DZ1201001,16111106001).上海市科技创新行动计划(15DZ1201001,16111106001)资助 （15DZ1201001,16111106001）
