A lightweight carbon nanofiber-based 3D structured matrix with high nitrogen-doping level for lithium metal anodes  

用于锂金属负极的轻质、高掺氮量碳纳米纤维基三维集流体（英文）

作　　者：Haoliang Wu Yunbo Zhang Yaqian Deng Zhijia Huang Chen Zhang Yan-Bing He Wei Lv Quan-Hong Yang 吴浩良;张云博;Yaqian Deng;邓亚茜;黄志佳;张琛;贺艳兵;吕伟;杨全红

机构地区：[1]Nanoyang Group, State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University [2]Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University [3]Engineering Laboratory for Functionalized Carbon Materials, Shenzhen Key Laboratory for Graphene-based Materials, Graduate School at Shenzhen, Tsinghua University

出　　处：《Science China Materials》2019年第1期87-94,共8页中国科学（材料科学（英文版）

基　　金：the financial support from the Guangdong Natural Science Funds for Distinguished Young Scholar (2017B030306006); the National Natural Science Foundation of China (51772164, U1601206 and U1710256); the National Key Basic Research Program of China (2014CB932400);Shenzhen Technical Plan Project (JCYJ20150529164918734 and JCYJ20170412171359175)

摘　　要：Lithium metal is considered to be the most promising anode material for the next-generation rechargeable batteries. However, the uniform and dendrite-free deposition of Li metal anode is hard to achieve, hindering its practical applications. Herein, a lightweight, free-standing and nitrogen-doped carbon nanofiber-based 3D structured conductive matrix(NCNF), which is characterized by a robust and interconnected 3D network with high doping level of 9.5 at%, is prepared by electrospinning as the current collector for Li metal anode. Uniform Li nucleation with reduced polarization and dendrite-free Li deposition are achieved because the NCNF with high nitrogen-doping level and high conductivity provide abundant and homogenous metallic Li nucleation and deposition sites. Excellent cycling stability with high coulombic efficiency are realized. The Li plated NCNF was paired with LiFePO4 to assemble the full battery, also showing high cyclic stability.锂金属是未来二次电池实现高能量密度化的关键负极材料,然而,如何实现锂金属的均匀和无枝晶沉积是目前制约其实际应用的关键问题.本论文采用静电纺丝技术及高温碳化方法制备了一种轻质、高掺氮量(9.5 at%)的三维碳纳米纤维集流体.该集流体较低的密度能提升基于整个电池的能量密度,而且高掺氮量使其具备亲锂的特性,从而有效降低锂离子在其表面的初始形核过电位,得到均匀的金属锂种子层,实现后续金属锂的均匀沉积.这种三维结构有效抑制了锂枝晶的产生,降低了电池的极化,金属锂沉积/脱除测试中其库伦效率在循环250圈后仍可保持在98%以上.将其沉积金属锂后与LiFePO_4组装全电池,电池极化降低,在循环300圈后容量保持率可达82.4%,表现出很好的应用前景.

关 键 词：lithium metal anode NUCLEATION dendrite-free NITROGEN-DOPING OVERPOTENTIAL 

分 类 号：TQ342.742[化学工程—化纤工业]