一个松果引发的灵感:高性能、长寿命硅负极设计
详细信息 查看官网全文
- 英文论文题名：A pinecone-inspired nanostructure design for long-cycle and high performance Si anode
- 论文作者：薛迎辉 ; 肖遥 ; 张琴 ; 张涛 ; 付磊
- 英文论文作者：Yinghui Xue ; Yao Xiao ; Qin Zhang ; Tao Zhang ; Lei Fu ; College of Chemistry and Molecular Science ; Wuhan University
- 年：2016
- 作者机构：武汉大学化学与分子科学学院;
- 论文关键词：硅负极 ; 石墨烯 ; 松果结构
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十一分会：纳米材料与器件
- 语种：中文
- 分类号：TM912
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十一分会 ; 纳米材料与器件
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：263k
- 原文格式：D
- 会议级别：全国
摘要
与石墨相比,硅负极具有超高的理论比容量和较低的脱锂电位,是一种有潜力的负极材料。但是,硅负极也存在一些缺点,即充放电过程中体积变化剧烈和固体电解质(SEI)膜不稳定。为了提高硅负极的性能,必须要释放体积变化带来的应力和稳定SEI膜。我们通过化学气相沉积法(CVD)在负载了硅纳米粒子的石墨烯泡沫上又生长了一层石墨烯,将硅封装在石墨烯和石墨烯泡沫中,形成了一种类似松果的三维异质结构。石墨烯泡沫为硅纳米粒子提供了一个三维骨架,同时也一个是三维的导电网络。硅纳米粒子牢牢地嵌在石墨烯泡沫表面,提供了一个较大的比表面积,有利于电解液的接触和锂离子的传导,减小了体积变化的应力。硅表面的石墨烯是部分交叠的,就像松果的鳞片一样,避免硅与电解液的接触,也能通过层间滑移缓冲硅的膨胀,保持了结构完整性。因此石墨烯封装的硅负极能够有较好的倍率性能(8400 mA/g下容量达800 mAh/g)和循环稳定性(2100 mA/g下循环300周容量可达1600 mAh/g),性能得到了提高。
Inspired by pinecone, here we develop a novel kind of direct chemical vapour deposition(CVD) derived graphene-encapsulated porous Si nanoparticles(NPs) on graphene foam(GF). The CVD derived graphene sheets on the surface of Si NPs are partly overlapped, act as the squamae of pinecone, preventing the direct exposure to the electrolyte. When the Si NPs expand, a sliding between the graphene layers occurs, providing an effective way to accommodate the volume expansion and stabilize the solid electrolyte interphase. As a result, the pinecone-like graphene-encapsulated Si electrodes exhibit a high capacity of 1600 mAhg~(-1) at a current density of 2100 mAg~(-1) after 300 cycles and a capacity higher than 800 mAhg~(-1) at a current density of 8400 mAg~(-1).
Inspired by pinecone, here we develop a novel kind of direct chemical vapour deposition(CVD) derived graphene-encapsulated porous Si nanoparticles(NPs) on graphene foam(GF). The CVD derived graphene sheets on the surface of Si NPs are partly overlapped, act as the squamae of pinecone, preventing the direct exposure to the electrolyte. When the Si NPs expand, a sliding between the graphene layers occurs, providing an effective way to accommodate the volume expansion and stabilize the solid electrolyte interphase. As a result, the pinecone-like graphene-encapsulated Si electrodes exhibit a high capacity of 1600 mAhg~(-1) at a current density of 2100 mAg~(-1) after 300 cycles and a capacity higher than 800 mAhg~(-1) at a current density of 8400 mAg~(-1).
引文
[1]Xue Y.;Deng J.;Wang C.;Mendes R.G.;Chen L.;Xiao Y.;Zhang Q.;Zhang T.;Hu X.;Li X.;Rümmeli M.H.;Fu L.J.Mater.Chem.A 2016,4:5395