工程科学学报，第41卷，第1期：111-116,2019年1月 Chinese Journal of Engineering,Vol.41,No.I:111-116,January 2019 D0L:10.13374/j.issn2095-9389.2019.01.012;htp:/journals.ustb.edu.cm 静电纺丝法制备空心钛酸锂材料 王瑜东12)，杨凯)四，张明杰，李建玲2》，高飞，刘皓)，耿萌萌) 1)中国电力科学研究院有限公司新能源与储能运行控制国家重点实验室，北京100192 2)北京科技大学治金与生态工程学院，北京100083 区通信作者，E-mail:yangkai(@cpi.sgcc.com.cn 摘要为进一步提升钛酸锂材料的性能，本文在传统静电纺丝技术的基础上，将纺丝喷头改进成内外嵌套的同轴喷头，以 两种溶液的形式进行同轴共纺，得到了具有空心结构的钛酸锂纤维丝.将其与传统静电纺丝法制备的实心结构钛酸锂纤维丝 进行对比，结果表明：空心钛酸锂材料粒度均一、无团聚现象，材料具有明显的空心结构，结晶性能良好，比表面积是实心结构 的1.3倍.形貌结构的改善极大地提高了空心钛酸锂材料的电化学性能，表现为小倍率下二者的放电比容量接近理论比容 量，但在20C倍率下空心结构的钛酸锂材料优于实心钛酸锂，仍可达到130mAh·g',循环200周后容量保持率仍达98%，具 有良好的稳定性：循环伏安和交流阻抗曲线也表明：空心结构使得钛酸锂材料的极化程度减少，电化学反应阻抗降低，更有利 于电化学反应的进行 关键词钛酸锂；静电纺丝：空心结构：储能：锂离子电池 分类号TG142.71 Fabrication of hollow lithium titanate material by electrospinning WANG Yu-dong2),YANG Kai,ZHANG Ming-jie),LI Jian-ling?,GAO Fei,LIU Hao,GENG Meng-meng 1)State Key Laboratory of Operation and Control of Renewable Energy Storage Systems,China Electric Power Research Institute.Beijing 100192,Chi- a 2)School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:yangkai@epri.sgce.com.cn ABSTRACT Lithium titanate (Li TisO,LTO)is an important material to be used as an anode for LIBs (Li'ion battery).LTO is a zero-strain material (i.e.,no structural change occurs during Li insertion/extraction).Although LTO is a very safe material that can be used as an anode material in high and low temperature environment,its rate capability is compromised by its low electronic conduc- tivity and poor Li'diffusion coefficient.In the recent years,considerable research around the world has focused on improving LTO rate performance.Efforts to achieve better electrical conduction between LTO particles have included LTO particle size control,conductive- material surface coatings,and alien ion doping.However,in this study electrochemical properties were improved by changing the mor- phology of LTO.Based on traditional electrospinning technology,LTO fibers with a hollow structure were produced using a nested coax- ial nozzle modified from the conventional spinning nozzle and coaxial cospinning with two different solutions.A comparison of this re- sults with those of solid LTO prepared by traditional electrospinning technology demonstrates that hollow LTO is characterized by uni- form particle size and no agglomeration,along with an obvious hollow structure,clear crystal lattice stripes,and good crystallization property.The specific surface of this hollow LTO is 1.3 times than its solid counterpart.This morphological change greatly improves the electrochemical performance of the material.Although the discharge specific capacities of both the solid and hollow LTO are close to the theoretical value for small ratios,the hollow LTO is superior to its solid counterpart at 20C.The discharge specific capacity of the hollow LTO can reach 130 mA.hg at 20C,and after 200 cycles,its capacity retention ratio remains at 98%,which suggests good 收稿日期：2017-12-20 基金项目：国家自然科学基金资助项目(51407166)：国网公司科技资助项目(DG71-16015)工程科学学报,第 41 卷,第 1 期:111鄄鄄116,2019 年 1 月 Chinese Journal of Engineering, Vol. 41, No. 1: 111鄄鄄116, January 2019 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2019. 01. 012; http: / / journals. ustb. edu. cn 静电纺丝法制备空心钛酸锂材料 王瑜东1,2) , 杨 凯1)苣 , 张明杰1) , 李建玲2) , 高 飞1) , 刘 皓1) , 耿萌萌1) 1) 中国电力科学研究院有限公司新能源与储能运行控制国家重点实验室,北京 100192 2) 北京科技大学冶金与生态工程学院,北京 100083 苣 通信作者, E鄄mail: yangkai@ epri. sgcc. com. cn 摘 要 为进一步提升钛酸锂材料的性能,本文在传统静电纺丝技术的基础上,将纺丝喷头改进成内外嵌套的同轴喷头,以 两种溶液的形式进行同轴共纺,得到了具有空心结构的钛酸锂纤维丝. 将其与传统静电纺丝法制备的实心结构钛酸锂纤维丝 进行对比,结果表明:空心钛酸锂材料粒度均一、无团聚现象,材料具有明显的空心结构,结晶性能良好,比表面积是实心结构 的 1郾 3 倍. 形貌结构的改善极大地提高了空心钛酸锂材料的电化学性能,表现为小倍率下二者的放电比容量接近理论比容 量,但在 20C 倍率下空心结构的钛酸锂材料优于实心钛酸锂,仍可达到 130 mA·h·g - 1 ,循环 200 周后容量保持率仍达 98% ,具 有良好的稳定性;循环伏安和交流阻抗曲线也表明:空心结构使得钛酸锂材料的极化程度减少,电化学反应阻抗降低,更有利 于电化学反应的进行. 关键词 钛酸锂; 静电纺丝; 空心结构; 储能; 锂离子电池 分类号 TG142郾 71 收稿日期: 2017鄄鄄12鄄鄄20 基金项目: 国家自然科学基金资助项目(51407166);国网公司科技资助项目(DG71鄄16鄄015) Fabrication of hollow lithium titanate material by electrospinning WANG Yu鄄dong 1,2) ,YANG Kai 1)苣 ,ZHANG Ming鄄jie 1) ,LI Jian鄄ling 2) ,GAO Fei 1) ,LIU Hao 1) ,GENG Meng鄄meng 1) 1) State Key Laboratory of Operation and Control of Renewable Energy & Storage Systems, China Electric Power Research Institute. Beijing 100192, Chi鄄 na 2) School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing,Beijing 100083, China 苣 Corresponding author, E鄄mail: yangkai@ epri. sgcc. com. cn ABSTRACT Lithium titanate (Li 4Ti 5O12 , LTO) is an important material to be used as an anode for LIBs (Li + ion battery). LTO is a zero鄄strain material (i. e. , no structural change occurs during Li insertion / extraction). Although LTO is a very safe material that can be used as an anode material in high and low temperature environment, its rate capability is compromised by its low electronic conduc鄄 tivity and poor Li + diffusion coefficient. In the recent years, considerable research around the world has focused on improving LTO rate performance. Efforts to achieve better electrical conduction between LTO particles have included LTO particle size control, conductive鄄 material surface coatings, and alien ion doping. However, in this study electrochemical properties were improved by changing the mor鄄 phology of LTO. Based on traditional electrospinning technology, LTO fibers with a hollow structure were produced using a nested coax鄄 ial nozzle modified from the conventional spinning nozzle and coaxial cospinning with two different solutions. A comparison of this re鄄 sults with those of solid LTO prepared by traditional electrospinning technology demonstrates that hollow LTO is characterized by uni鄄 form particle size and no agglomeration, along with an obvious hollow structure, clear crystal lattice stripes, and good crystallization property. The specific surface of this hollow LTO is 1郾 3 times than its solid counterpart. This morphological change greatly improves the electrochemical performance of the material. Although the discharge specific capacities of both the solid and hollow LTO are close to the theoretical value for small ratios, the hollow LTO is superior to its solid counterpart at 20C. The discharge specific capacity of the hollow LTO can reach 130 mA·h·g - 1 at 20C, and after 200 cycles, its capacity retention ratio remains at 98% , which suggests good